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FIELD OF INVENTION
[0001] The present invention relates generally to tubular implantable prosthetic devices such as vascular grafts and other endoprostheses. More particularly, the present invention relates to a graft formed of porous expanded polytetrafluoroethylene (ePTFE) which supports a stent in an ePTFE composite graft-stent device.
BACKGROUND OF THE INVENTION
[0002] Intraluminal devices such as grafts and stents are known for treating stenosis, stricture, aneurysms and the like. These devices may be implanted either transluminally in a minimally invasive procedure or may be surgically implanted.
[0003] Such intraluminal devices provide a technique for expanding a constricted vessel or for maintaining an open passageway through a vessel. One common technique used to hold open a blocked or constricted vessel such as a blood vessel is to employ a vascular stent. Stents are implantable intraluminal devices typically formed of wire which may be radially expanded to hold open constricted vessels. Thus, wire stents are useful to prevent restenosis of a dilated vessel or to eliminate the danger of reocclusion of the vessel. In addition, wire stents can also be used to reinforce various lumen in danger of collapse. However, stents are not generally designed as conduits or bypass devices.
[0004] Intraluminal or endoprosthetic grafts, however, are designed as bypass devices which allow fluid flow therethrough. Often, these devices are percutaneously implanted within the vascular system to reinforce collapsing, partially occluded, weakened or abnormally dilated localized sections of, e.g., a blood vessel. Grafts may also be surgically implanted by anastomosis to replace a badly damaged portion of vessel.
[0005] Vascular grafts may be manufactured from a variety of bio-compatible materials. For example, it is well known to use extruded tubes of polytetrafluoroethylene (PTFE) as vascular grafts. PTFE is particularly suitable as it exhibits superior biocompatibility. PTFE tubes may be used as vascular grafts in the replacement or repair of blood vessels because PTFE exhibits low thrombogenicity. Further, expanded PTFE (ePTFE) tubes have a microporous structure which allows natural tissue ingrowth and cell endothelialization once implanted into the vascular system. This contributes to long term healing and graft patency.
[0006] Grafts formed of ePTFE have a fibrous state which is defined by interspaced nodes interconnected by elongated fibrils. The spaces between the node surfaces that are spanned by the fibrils are defined as the internodal distance (IND). The art is replete with examples of vascular grafts made of microporous ePTFE tubes useful as vascular grafts. The porosity of an ePTFE vascular graft is controlled by varying the IND of the microporous structure of the tube. An increase in the IND within a given structure results in enhanced tissue ingrowth, as well as, cell endothelialization along the inner surface thereof. Increasing the porosity of the tubular structure, however, reduces the ability of the graft to retain a suture placed therein during implantation and tends to exhibit low axial tear strength. In order to strike an effective balance between porosity and radial strength, multi-layer ePTFE tubes have been developed. The porosity of these multilayered tubes vary as between the outer and inner layers to achieve a composite structure having sufficient porosity for tissue ingrowth and cell endothelialization while still retaining sufficient radial strength.
[0007] It is known in the art to use stents in combination with vascular grafts and other endoprostheses. Stents may be positioned at one or both ends of a graft to support the graft within a portion of the vessel. Thus positioned, the stents help fix the graft to the vessel wall. In addition, stents serve to keep the lumen open and to anchor the graft in place. A single stent may also be employed in combination with a graft to allow the graft to “float” downstream toward the affected vessel. Once properly positioned, the single stent is expanded to anchor the graft in place.
[0008] Several techniques for securing one or more stents to a graft are known. For example, hooks or barbs extending from the stent have been used for securing stents to a graft. Alternatively, a stent may be sutured to a graft. Each of these techniques requires either specialized stent attachment means or secondary procedures to secure the stents to the graft.
[0009] Traditional stents have various shapes and sizes depending upon their intended function. For example, structures which have previously been used as stents include coiled stainless steel springs, helically wound coiled springs manufactured from an expandable heat-sensitive material, expanding stainless steel stents formed of stainless steel wire in a “zig-zag” pattern, cage-like devices made from malleable metal, and flexible tubes having a plurality of separate expandable ring-like scaffold members which permit radial expansion of a graft. Each of these devices is designed to be radially compressible and expandable so that it will easily pass through a blood vessel in a collapsed state and can be radially expanded to an implantable size after the target area of the vessel has been reached. Radial expansion and contraction of each of these causes associated longitudinal expansion and contraction of the stent.
[0010] Such expandable stents may be supported between the layers of a multi-layer tubular graft. The expandable stent would anchor and support the multi-layer tube within the lumen. Upon radial expansion, the stent would hold the graft outwardly against the inner wall of the lumen.
[0011] One example of such a graft-stent combination is shown in U.S. Pat. No. 5,123,917 issued to Lee et al. A stent-graft combination shown therein includes a plurality of separate scaffold members (stents) mounted between an inner tube and an outer tube forming the multi-layer graft. In one embodiment of this invention, the scaffold members are free floating within an intermediate pocket formed by the inner and outer tubes. In another embodiment, the scaffold members are adhesively affixed to the outer surface of the inner tube. In yet another embodiment of this invention, the inner and outer tubes are adhered to each other in such a manner that separate pockets are formed in which individual scaffold members are placed within each pocket.
[0012] In each of these different embodiments of the '917 patent, radial expansion of the scaffold member causes a change in the longitudinal expanse thereof. Thus, a drawback to the device shown in the '917 patent is that the net length of the scaffold member increases as the graft contracts. Accordingly, this increase in the net length of the scaffold member increases the stress forces on the graft as well as tends to delaminate the layers. Thus, these stress forces increase the likelihood that the inner tube will become separated from the outer tube and/or that the graft will tear upon expansion of the scaffold members.
[0013] Accordingly, it would be desirable to provide an improved intraluminal device, in particular, an ePTFE graft-stent composite device with improved radial strength that allows for the deployment of a stent and graft simultaneously with the stent already permanently positioned on the graft such that additional stress is not placed on the graft by the stent upon expansion.
SUMMARY OF THE INVENTION
[0014] In accordance with the present invention, an improved composite graft-stent device is provided. More particularly, the present invention is formed from two non thrombogenic tubes which are laminated or fused together with one or more stents secured therebetween. This composite device is then expanded to place it in intimate contact with the inner surface of the lumen in which it is positioned.
[0015] The composite device is preferably an implantable intraluminal device with a first porous tube that has two opposed ends, an interior luminal surface and an exterior surface. The composite device also contains a second porous tube which is disposed concentrically about the exterior surface of the first tube and is secured to the exterior surface of the first tube. A radially expandable member is disposed about the exterior surface of the first tube and is longitudinally immobilized between the first and second tubes when they are secured. In the present invention, the second tube is secured to the first tube by fusion or by lamination.
[0016] The radially expandable member between the two tubes includes a longitudinal expanse. As used herein, the term “longitudinal expanse” means the width of the radially expandable member as measured along the axis of the tube. In the present invention, when the member is expanded, there is no distortion along the longitudinal expanse of the member, e.g., the width remains constant as the member is expanded. The member is preferably an expandable stent.
[0017] The expandable stent of the invention includes an elongated element with a first end and a second opposed end. In one embodiment of the invention, the elongated element is formed in a generally circular configuration with the first end adjacent to and overlapping the second opposed end. The stent is expandable through the relative movement of the first end with respect to the second opposed end.
[0018] In another embodiment of the invention, the end extent of the first end of the elongated element has a plurality of second end engagement means for engaging the distal end of the second end to provide finite adjustability to the stent.
[0019] In yet another embodiment of the present invention, the radially expandable stent includes an elongate element having a first end and a second opposed end. This elongate element is formed in a generally circular configuration with the first and second ends in axial alignment to each other. In this embodiment of the invention, the second end has an elongate open-ended channel wherein radial expansion is achieved by movement of the first end out of the open-ended channel of the second end.
[0020] The implantable intraluminal device of the present invention is preferably fabricated out of a biocompatible metal. Most preferably, the implantable intraluminal device is stainless steel, platinum, gold, nitinol, tantalum and alloys thereof.
[0021] The first and second tubes of the present invention are preferably fabricated out of a bio-compatible material. Most preferably, the first and second tubes are fabricated out of expanded polytetrafluoroethylene (ePTFE).
[0022] In the present invention, a stent may be disposed about the exterior surface of the first tube adjacent to either of the first or second ends. Alternatively, a stent may be disposed about the exterior surface of the first tube at both ends. In yet another embodiment, a plurality of stents may be disposed about the exterior surface of the fist tube and longitudinally spaced between stents located at the first and second ends of the device.
[0023] In the present invention, the device may be expanded by an inflation force. Preferably, the inflation force is supplied by inflating a balloon catheter.
[0024] The process of the present invention hereby incorporates by reference all of the limitations described above for the intraluminal implantable device. By way of summary, in the process of the invention an implantable intraluminal device is provided which includes a first luminal porous tube having first and second ends, an interior luminal surface and an exterior surface. One or more radially expandable members is/are then radially disposed about the exterior surface of the first tube. A second porous tube is then concentrically positioned over the first tube and the radially expandable member(s). The first tube is then secured to the second tube so that one or more expandable members is/are immobilized along the longitudinal axis of the first and second tubes.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] The present invention can be further understood with reference to the following description in conjunction with the appended drawings, wherein like elements are provided with the same reference numbers. In the drawings:
[0026] FIG. 1 is a longitudinal cross-section of the composite graft-stent of the present invention.
[0027] FIG. 2 is a front view of the “key-ring” type stent employed in the composite graft-stent of FIG. 1 .
[0028] FIG. 3 is a front view of another embodiment of a stent of the composite graft-stent of FIG. 1 .
[0029] FIG. 4 is a front view, partially in section of a still further embodiment of a stent of the composite graft-stent of FIG. 1 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0030] Now turning to FIG. 1 , a longitudinal cross-section of the preferred embodiment of the graft-stent composite device 10 is shown. This device 10 includes a multilayer graft 25 which is formed of inner and outer tubes 12 and 22 that are preferably formed of expandable polytetrafluoroethylene (ePTFE). Although it is preferred that tubes 12 and 22 be made of ePTFE, any appropriate bio-compatible material, such as porous polyurethane, is also contemplated. Other potential materials for this application include DACRON, a proline mesh or the like. Ideally, the material should be inert and should not promote a significant amount of scar formation.
[0031] Graft 25 has first and second opposed ends 14 and 16 , respectively. Tube 12 includes an exterior surface 18 and an interior luminal surface 20 . Tube 22 has an interior surface 24 and an exterior vascular surface 26 . Tube 22 is disposed concentrically over the exterior surface 18 of tube 12 to form the multilayer graft 25 .
[0032] A plurality of longitudinally spaced stents 28 are disposed between the exterior surface 18 of tube 12 and the interior surface 24 of tube 22 . As will be described hereinbelow, each stent 28 is of the type which may be radially expanded. Stents 28 are longitudinally immobilized between tubes 12 and 22 when they are secured to each other. The stents 28 are positioned at spaced locations along the multi-layer graft 25 in numbers which may be selected based on use and application of the device 10 .
[0033] FIG. 1 shows tubes 12 and 22 laminated together to form graft 25 with stents 28 disposed therebetween. Although FIG. 1 shows tubes 12 and 22 laminated together, any appropriate method of securement, such as fusion, is contemplated. The lamination of tubes 12 and 22 causes stents 28 to be immobilized along the longitudinal axis of the multi-layer graft 25 .
[0034] Now turning to FIG. 2 , a preferred embodiment of stent 28 is shown. Stent 28 may be formed from a wire 30 which is wound in the shape of a simple circle generally described as a “key-ring.” The circular wire 30 includes a first end 34 adjacent to and overlapping a second opposed end 36 . The wire 30 is radially expandable by movement of first end 34 and second end 36 in opposing directions relative to each other as indicated by arrow A. Radial expansion is accomplished by, for example, the expansion of a balloon catheter exerting radial pressure on wire 30 . This radial expansion is achieved without a change in the longitudinal expanse 32 of the wire 30 which is shown in FIG. 1 . While balloon expansion is described, it is also contemplated that stent 28 may be of the self-expanding variety.
[0035] Now with reference to FIG. 3 , a further embodiment of the stent of the present invention is shown. Stent 28 ′ may be formed from a wire employing a simple “ratchet” design. The wire 30 ′ is formed in a circular configuration and includes a first end 34 ′ adjacent to and overlapping its second opposed end 36 ′. Several ratchet-like teeth 38 ′ are located at an end extent 40 ′ of the first end 34 ′. The other end 36 ′ includes a pawl 41 ′ at a distal end 42 ′ thereof for adjustable engagement with teeth 38 ′. Upon relative movement of opposed ends 34 ′ and 36 ′, teeth 38 ′ are engaged by pawl 41 ′ to provide adjustable interlocking therebetween. This allows the diameter of the circular stent 28 ′ to be adjustably expanded in incremental fashion, to set the diameter thereof at discrete increments.
[0036] Now with reference to FIG. 4 , an additional embodiment of a stent is shown. Stent 28 ″ is a wire stent employing telescoping-ends. The wire 30 ″ is formed in a circular configuration and includes a first end 34 ″ that is positioned in general axial alignment with a second opposed end 36 ″. A distal portion 34 a ′ of first end 34 ″ telescopes into an elongate open-ended channel 44 ″ formed at opposed end 36 ″. The diameter of the stent 28 ″ is contracted and expanded by movement of first end 34 ″ into and out of open-ended channel 44 ″.
[0037] The various embodiments of each of the stents 28 described herein are preferably manufactured out of a bio-compatible metal. Most preferably, the bio-compatible metal is stainless steel, platinum, gold, nitinol, tantalum and alloys thereof.
[0038] One or more such stents 28 may be disposed between tubes 12 and 22 . For example, in one embodiment a single stent 28 is disposed about one end of tube 12 . In an alternative embodiment of the invention, two stents 28 are disposed about each end of tube 12 . In yet another embodiment of the invention, several stents 28 are disposed about the exterior surface 18 of tube 12 and are longitudinally spaced therealong between the two ends 14 and 16 of tube 12 .
[0039] While the preferred embodiments of the invention are shown and described below, other embodiments that fall within the scope of the disclosure and appended claims are also contemplated.
[0040] The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention and all such modifications are intended to be included within the scope of the following claims.
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An implantable intraluminal device includes a multilayer composite tubular device supporting one or more stents between the layer thereof. A first porous elongate tube includes an exterior surface and an interior luminal surface. A radially expandable member is disposed about the exterior surface of the first tube. A second porous elongate tube is disposed concentrically over the first tube and is secured thereto so that the radially expandable member is longitudinally immobilized therebetween.
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TECHNICAL FIELD
The present invention relates generally to telecommunications systems and more particularly to dynamic route generation for real time network restoration using a pre-plan generation methodology.
BACKGROUND OF THE INVENTION
Telecommunications networks are subject to failure and must be restored after failure. Two competing methodologies have evolved to devise plans to restore telecommunications networks after failure: pre-plan and dynamic route generation. In the pre-plan methodology, restoral routes are generated for every traffic route within the network prior to network failure. Plans are then created to implement the restoral routes. These plans are known as “pre-plans,” and each pre-plan contains a set of commands for issuance to restoration network devices to activate the restoral routes. “Restoration network devices” are devices, such as digital cross connects (DXCs), that are used to restore traffic on the network in the event of network failure.
The pre-plan methodology has the benefit of generating optimal restoral routes. In general, all possible restoral routes (“pre-plans”) within a given a cost limit are generated for each traffic trunk, and the best (i.e., lowest cost) restoral route among those generated is selected for use in restoring the network. A major disadvantage of the pre-plan methodology is that it takes a long time to generate a batch of pre-plans for an entire telecommunications network. Moreover, given that network topology is generally very dynamic, there is a great likelihood that the pre-plans are quickly outdated after generation.
In the dynamic route generation methodology, a restoral route is generated for an impacted traffic route in real time in response to the network failure. Dynamic route generation is also referred to as “real time restoration.” Dynamic route generation generally places a cost limit on possible restoral routes and only generates the routes that fall within the cost limit. Typically, the cost limits used in pre-plan route generation are substantially higher than those used in dynamic route generation. The low cost limits employed in dynamic route generation ensure that very few routes are generated and considered; hence, increasing the speed with which a restoral route is generated.
One advantage of the dynamic route generation methodology is that it is very fast and uses current topology data. There is no need to generate a massive set of pre-plans as in the pre-plan methodology. A disadvantage suffered by the dynamic route generation methodology is that it often selects sub-optimal restoral routes for the sake of speed.
SUMMARY OF THE INVENTION
The present invention addresses the limitations of the prior art by providing a hybrid approach that combines the benefits of the pre-plan methodology with the benefits of the dynamic route generation methodology. In one embodiment of the present invention, pre-plan sub-routes are generated, where each sub-route is a portion of the network that may be used in formulating a restoral route. Lowest cost sub-routes are combined to quickly produce a low cost restoral route. The restoral route is dynamically generated using the pre-plan generated sub-routes.
In accordance with a first aspect of the present invention, a method is practiced in a telecommunications network that has nodes which are interconnected by connections. The telecommunications network also includes a computing resource for directing restoration of the network from a failure. The computing resource generates restoral sub-routes where each restoral sub-route is a portion of the network that has nodes and connections that connect the nodes. These nodes include end nodes that correspond to respective ends of the sub-routes. Each restoral sub-route has an associated cost less than a threshold cost amount. A failure is identified in the network and a traffic route that is impacted by the failure is also identified. The traffic route includes nodes that are logically divisible into nodes positioned on the left side of the failure and nodes on the right side of the failure. Selected ones of the sub-routes that have a selected end node that is one of the nodes of the traffic route impacted by the failure are identified. The end node is positioned on the left side of the failure are identified. Given ones of the sub-routes are identified where the given sub-routes have an end node that is one of the nodes of the traffic route that is impacted by the failure and the given end node is positioned on the right side of the failure. One of the selected left side sub-routes and one of the given right side sub-routes are employed to create a restoral route for restoring the telecommunications network from failure.
In accordance with a further aspect of the present invention, a data structure is provided for storing information about a sub-route. The sub-route constitutes a route formed by the subset of the nodes and the connections that may be used in formulating restoral routes to recover from a failure in a telecommunications system. Information regarding a first end node and a second end node of the sub-route is stored in the data structure. Information stored in the data structure is used in formulating a restoral route.
In accordance with another aspect of the present invention, a method of generating restoral routes for failure in a network that affects nodes along a given traffic route is practiced in the telecommunications network. Sub-routes are identified that include as an end node one of the nodes on a given traffic route. A first subset of the sub-routes that share common end nodes that are not on the given traffic routes are identified. If there are sub-routes in the first subset, sub-routes are selected that when combined produce the restoral route based upon their associated costs.
In accordance with yet another aspect of the present invention, a telecommunications network has a restoration system and nodes that are interconnected by connections. The restoration system includes a sub-route generator for generating sub-routes. The sub-routes have costs that do not exceed a cost limit. Each sub-route is a path network that interconnects selected nodes. The restoration system also includes a restoral route generator for dynamically generating restoral routes for restoring the network in response to the failure of the network. The restoral route is created from a first and a second sub-route that is generated by the sub-route generator.
The present invention may also be practiced with a pre-plan methodology. In particular, failure spans are identified in the network and restoral routes are generated for each failure span. The restoral routes are generated from sub-routes as described above.
BRIEF DESCRIPTION OF THE DRAWINGS
An illustrative embodiment of the present invention will be described below relative the following drawings:
FIG. 1 illustrates the topology of a telecommunications network that is suitable for practicing the illustrative embodiment of the present invention.
FIG. 2 illustrates a centralized restoration system for dynamically generating restoral routes in accordance with the illustrative embodiment of the present invention.
FIG. 3 is a flow chart illustrating the steps performed by the real time restoration process of FIG. 2 .
FIG. 4 is a flow chart illustrating the steps that are performed to build the sub-route tables.
FIG. 5 is a flow chart illustrating the steps that are performed to generate a restoral route.
FIG. 6 illustrates a centralized restoration system that implements a pre-plan restoral generation approach in accordance with the illustrative embodiment of the present invention.
FIG. 7 is a flow chart illustrating the steps that are performed to build an intersection table.
FIG. 8 is a flow chart illustrating the steps that are performed when a second series of analyses are performed to fold out sub-routes.
FIGS. 9A and 9B are flow charts illustrating the steps that are performed to select a restoral route based upon route intersections.
FIG. 10 illustrates an example of an intersection table that includes results of a single series of analyses.
FIG. 11 illustrates an example of an intersection table that holds the results of two series of analyses.
FIG. 12 is a flow chart illustrating the steps that are performed when a pre-plan restoration process is performed in the illustrative embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The illustrative embodiment of the present invention provides an approach to generating restoral plans for a telecommunications network that chooses close to optimal restoral routes without incurring the large time and computation overhead traditionally associated with pre-plan methodologies. The illustrative embodiment adopts a dynamic route generation approach that employs a route generation process akin to a pre-plan methodology. The route generation process is streamlined so that it can be executed with the speed necessary for real time restoration. The streamlined approach processes network topology data to generate a large number of possible restoral sub-routes. For each traffic trunk that is impacted by the failure, selected sub-routes are combined to generate restoral routes.
The illustrative embodiment has the benefit of being substantially faster than the pre-plan methodology. The restoral routes generated by the illustrative embodiment are close to optimal, unlike the restoral routes generated by traditional dynamic route generation methodologies. The “sub-routes” include partial restoral routes and complete restoral routes.
FIG. 1 depicts the topology of a telecommunications network 100 in which the illustrative embodiment of the present invention may be practiced. A “telecommunications network,” as used herein, includes any computer network, telephone network or other combination of nodes that communicate with each other that can carry both voice and data. A “node” refers to a point of connection into a network. The telecommunications network 100 includes restoration nodes (labeled A-Q in FIG. 1 ). Each restoration node is a network device that is used to restore traffic in the event of a network outage or failure. These restoration nodes may be DXCs, which are complex digital switches capable of automatically switching trunks upon external command. A “trunk” is a logical channel of communication capacity which traverses one or more nodes and one or more links between nodes. In the depiction shown in FIG. 1, it is assumed that a single trunk connects restoration node A with restoration node D (note the boldface line interconnecting the nodes A-B-C-D).
The nodes shown in FIG. 1 are interconnected by spans of network capacity. Some of the spans are designated to carry live traffic whereas other spans are designated to carry spare capacity (which is used in restoration of the network). Although a single line is depicted in FIG. 1 to interconnect nodes, each line represents several spans, where each span is capable of carrying a plurality of trunks. A single span may, for example, support one or more DS 3 trunks. The trunk between nodes A and D traverses spans 112 , 114 and 116 . More generally, connections exist between nodes to facilitate communications among the nodes.
Those skilled in the art will appreciate that the network topology depicted in FIG. 1 is intended to be merely illustrative and not limiting of the present invention. The present invention may be practiced with other networks that include a different number of restoration nodes.
FIG. 2 depicts a centralized restoration system 200 that is suitable for practicing the illustrative embodiment of the present invention. The centralized restoration system 200 is responsible for issuing commands to the restoration network devices 202 in order to restore the network after outage or failure. The centralized restoration system acts as a restoral route generator for generating restoral routes. Data links 204 , such as those found in X.25 networks, connect the restoration network devices 202 with the centralized restoration system 200 . The centralized restoration system 200 also has an interface with a provisioning system 206 for updating the topology of the network 200 based on customer demands and needs. In the illustrative embodiment of the present invention, the provisioning system 206 is implemented using a mainframe computer system. Those skilled in the art will appreciate that a mainframe computer system need not be used; rather other types of computing systems may be used. The provisioning system 206 includes a network topology database 216 that holds topology data regarding the telecommunications network 100 . This topology data may be downloaded to the centralized restoration system 200 as needed (see Step 214 in FIG. 2 ). The nature of the topology data and the use of the topology data by the centralized restoration system 200 will be described in more detail below.
The centralized restoration system 200 may be implemented via computer processes on one or more computer systems. For example, the centralized restoration system 200 may be implemented as computer software package that runs on multiple server computer systems, such as a cluster of servers that employ the DEC Alpha processor from Digital Equipment Corporation. In general, the centralized restoration system may be implemented using a computing resource that implements the functionality described herein. The computing resource may be, for example, a computer system, a digital switch or other device that has a microprocessor.
The centralized restoration system 200 includes one or more storage devices for storing data and programs (as will be described below). The storage devices may include different varieties of devices, such as RAM, ROM, PROM, EPROM, EEPROM, magnetic disk drives, optical disk drives and/or floppy disk drives.
The centralized restoration system 200 includes a network device interface 210 that manages communications between the restoration network devices 202 and the centralized restoration system 200 . The restoration network devices 202 need not all be alike; rather they may be different varieties of physical devices. The network device interface 210 receives alarms 220 from the restoration network devices 202 when a network failure occurs and also receives actions 222 from a real time restoration process 208 for implementing restoral routes.
The centralized restoration system 200 runs the real time restoration process 208 to oversee restoration of the network 100 . The real time restoration process 208 may be implemented as a set of executable programs. The real time restoration process 208 reads and writes data from a restoration database 212 . This data includes a series of tables that are utilized in developing restoral routes. The real time restoration process 208 reads data from a copy of network topology database 214 , which has been copied from the provisioning system 206 . As was mentioned above, this database 214 includes network topology data, such as records having data about nodes, spans and ports. The real time restoration process 208 builds and utilizes an intersection table 218 , which will be described in more detail below.
FIG. 3 illustrates the steps that are performed to realize a network restoration in the illustrative embodiment of the present invention. Initially, alarms 220 are received over the data links 214 from restoration network devices 202 . The restoration network devices 202 generate alarms when a network failure occurs. These alarms are analyzed to identify the location of the failure within the telecommunications network. The alarms and methods for determining the location of network outages are described in more detail in application Ser. No. 08/758,111, entitled “Method and Apparatus for Determining Maximum Network Failure Spans for Restoration,” application Ser. No. 08/753,559, entitled “Method and Apparatus for Isolating Network Failures by Applying Alarms to Failure Spans” and application Ser. No. 08/753/560, entitled “Method and Apparatus for Isolating Network Failure by Correlating Paths Issuing Alarms with Failure Spans,” which were all filed on Nov. 26, 1996 and which are all incorporated explicitly by reference herein.
The alarms 220 are received by the real time restoration process 208 so that the real time restoration process detects the outage or failure that prompted the alarms (Step 302 in FIG. 3 ). The real time restoration process 208 analyzes alarms 220 to isolate the location of the network outage (Step 304 in FIG. 3 ). The process of isolating the location of the outage is described in more detail in the pending patent applications referenced above. The outage is isolated to a single “failure span,” where a failure span is a maximum length span that can be restored with a single restoral route. The trunks that are affected by the outage are identified and prioritized based upon characteristics of the trunk (Step 306 ). Certain trunks are assigned higher priority for early restoral.
The real time restoration process 208 then proceeds to build a set of sub-route tables (Step 308 in FIG. 3 ). In this capacity, the real time restoration process 208 acts as a sub-route generator. The sub-route tables include all sub-routes that may utilized to build restoral routes that fall within a designated cost limit. This cost limit serves as a threshold cost that may not be exceeded. Those skilled in the art will appreciate that a number of different cost limits may be used. Each of the sub-routes is built from spare capacity within the telecommunications network 100 . “Spare capacity” is capacity that is not currently assigned to carry network traffic. A “sub-route” constitutes a portion of the network that may be used as part of a restoral route. Each sub-route may be viewed as a path leading from a first end node to a second end node, where an end node constitutes a terminus node for a sub-route. One example of a cost limit is a number of inter-node hops. For example, in FIG. 1, if a cost limit of three inter-node hops is designated, then a route that traverses nodes I, E and F (i.e., three hops) is included in the sub-routes but a route that traverses I, E, F and G (i.e., four hops) is not.
Each sub-route table has the following format:
Sub-route
unsigned long
end_node_id1.
unsigned long
end_node_id2.
int
cost
int
num_spans
span
*span[4]
boolean
used_flag
The “end_node_id 1 ” field of the sub-route table identifies a first end node for the sub-route associated with the sub-route table. Similarly, the end_node_id 2 field holds an identifier for the other end node in the sub-route.
The “cost” field holds a value that identifies the cost of the sub-route (e.g., the number of internode hops in the sub-route).
The “num_spans” field identifies the number of spans in the sub-route.
The “*spans[ 4 ]” field is a pointer to the span records for the spans that are included in the sub-route. Where a cost limit of greater 4 internode hops is used, the spans[ ] array will include more than 4 elements.
The “used_flag” field is a boolean field that identifies whether the sub-route is being used or not. This allows a sub-route to be avoided where all spans of the sub-route are already in use.
Those skilled in the art will appreciate the format of the sub-route table set forth above is intended to be merely illustrative and not limiting of present invention. Those skilled in the art will appreciate that the information regarding routes need not be stored in a table but may also be stored in other varieties of data structures. Further, additional fields may be included in such data structures, and there is no need to include all of the fields that are set forth above.
Those skilled in the art will also appreciate that the sub-route tables may be built at a different time in the restoration process than shown in FIG. 3 . For example, the sub-route tables may be built before the identification and prioritization of the impacted trunks takes place (i.e., before Step 306 in FIG. 3 ). The sub-route tables may even be built before the network outages are detected. Details regarding the building of the sub-route tables will be provided below relative to FIG. 4 .
FIG. 4 depicts the steps that are performed to build sub-route tables in the illustrative embodiment of the present invention (i.e., Step 308 in FIG. 3 ). Initially, the real time restoration process 208 retrieves network topology data 214 from network topology database 216 (Step 402 in FIG. 4 ). Each of the components within the telecommunications network 100 may be modeled as an object or record within the network topology database 216 . The network data is used to build the sub-route tables. The real time restoration process 208 then specifies a cost limit that is to be applied for the sub-routes (Step 404 in FIG. 4 ). As was discussed above, this cost limit may be specified as a number of internode hops. As the sub-routes are built purely from spare capacity, all spans of spare capacity must be built from the specific capacities of the interconnections between nodes as identified by the topology data (Step 406 in FIG. 4 ).
The building of a sub-route table proceeds iteratively on a per end node pair basis. This process begins by the real time restoration process 208 selecting an end node pair (Step 408 in FIG. 4 ). All possible sub-routes that lie within a specified cost limit are generated for the given end node pair (Step 410 in FIG. 4 ). The cost associated with the generated sub-routes are assigned to the sub-routes (Step 412 in FIG. 4 ). This process is repeated until all end node pairs have been processed (see Step 414 in FIG. 4 ). The resulting sub-routes are sorted by end nodes and then by cost (Step 416 in FIG. 4 ).
An example is helpful to illustrate the identification of sub-routes in accordance with the flow chart of FIG. 4 . Suppose that a cost limit of three node hops is designated for the telecommunications network 100 depicted in FIG. 1 . Further suppose that the selected end nodes are end node A and end node F. The sub-routes that fall within the three hop cost limits include A-I-E-F and A-I-J-F. Sub-route A-B-J-F is excluded as lying along the impacted trunks.
Once all the sub-route tables have been built, the number of sub-route tables that are candidates for inclusion in the restoral route is reduced by excluding sub-routes that traverse the impacted section of the network, (i.e., the span or spans where the outage occurred) from selection (Step 310 in FIG. 3 ). The real time restoration process 208 begins to generate and implement restoral routes for each of the impacted trunks. The impacted trunks are processed one at a time based upon the priority established in Step 306 . Thus, the next step is to select an impacted traffic trunk that has the highest priority (Step 312 in FIG. 3 ). A restoral route is generated for the selected traffic trunk using sub-routes from the sub-route table, as will be described in more detail below relative to FIG. 5 (Step 314 ). The real time restoration process 208 creates actions 222 for implementing the restoral route by sending commands over the data links 204 to the restoration network devices 202 (Step 316 in FIG. 3 ). Examples of actions 222 include the cross connecting and disconnecting of trunks by the DXCs that constitute the restoration devices 202 . The restoration network devices 202 then proceed to implement the restoral routes (Step 318 in FIG. 3 ).
The restoration network devices 202 send confirmations back to the real time restoration process 208 to confirm that the appropriate actions have been taken. If the restoral route has been successfully implemented (see Step 320 in FIG. 3 ), the real time restoration process 208 verifies that traffic is restored in the telecommunications network over the implemented restoral route (Step 324 in FIG. 3 ). If the restoral route was not successfully implemented, the topology data stored within the restoration database 212 is updated to exclude the capacity associated with that restoral route for use in new restoral routes (Step 322 in FIG. 3 ). The process is repeated beginning at Step 314 of FIG. 3 .
If the restoral route is successfully implemented (see Step 320 in FIG. 3) and verification that the traffic has been restored is received (see Step 324 in FIG. 3 ), the real time restoration process 208 determines whether all impacted traffic trunks have been selected and processed (see Step 326 in FIG. 3 ). If there are remaining traffic trunks that have been impacted by the network outage, the traffic trunks are processed in sequence according to priority by repeating the above described steps beginning at Step 312 of FIG. 3 . On the other hand, once all of the impacted traffic trunks have been processed the real time restoration process 208 confirms that the outage has cleared (Step 328 in FIG. 3 ). When the outages clear, there should no longer be any alarms being received by the real time restoration process 208 from the impacted region. The real time restoration process 208 normalizes the traffic routes according to the traffic routing policies implemented therein (Step 330 in FIG. 3 ).
FIG. 5 depicts the steps that are performed in generating a restoral route for a given impacted trunk (i.e., Step 314 in FIG. 3 ). Initially, an intersection table is built (Step 502 in FIG. 5 ). The intersection table identifies instances where a sub-route that originates from a lefthand node intersects (i.e., shares at least one common node) with a sub-route that originates from a righthand node. A lefthand node is one that lies on the “left-side” of the network outage and a righthand node is one that lies on the “right-side” of a network outage. Such intersecting sub-routes are used to build a restoral route, as will be described in more detail below.
FIG. 7 depicts steps that are performed to build an intersection table (see Step 502 in FIG. 5 ). Initially, a lefthand node of an impacted trunk is selected (Step 702 in FIG. 7 ). For example, in the telecommunications system shown in FIG. 1, nodes A and B are lefthand nodes on the impacted trunk. The selected lefthand node is then “folded out.” Folding out entails identifying from the sub-route table all nodes that are end nodes from a sub-route that begins from the node being folded out. End nodes of sub-routes that fall along the “left-side” of the impacted trunk are excluded. Thus, sub-routes from nodes A to B will be excluded in the example case depicted in FIG. 1 . The “left-side” entries of the intersection table are then populated (Step 704 in FIG. 7 ). This process is repeated until all lefthand nodes have been selected (see Step 706 in FIG. 7 ).
The building of an intersection table next proceeds by filling in entries of the “right-side” field of the table. To that end, the righthand nodes of the impacted trunks are selected (Step 708 in FIG. 7 ). In the example depicted in FIG. 1, the righthand nodes include nodes C and D. The righthand nodes are folded out in a manner like that described relative to the lefthand nodes. The “right-side” entries of the intersection table are populated accordingly (Step 710 in FIG. 7 ). This process repeats itself for the righthand nodes beginning at Step 708 until all righthand nodes have been selected and processed (see Step 712 in FIG. 7 ).
FIG. 10 depicts an example of an intersection table. As can be seen in FIG. 10, each row in an intersection table corresponds to a node in the telecommunications network 100 . Each row includes a node field that identifies the node associated with the row. Each row also includes a “left-side” field and a “right-side” field. The “left-side” field holds identification information that identifies any lefthand node that is an end node of a sub-route that has as its other end node the node associated with the row. Likewise, the “right-side” field holds identification information that identifies any righthand nodes that are end nodes of a sub-route that has as its other end node, the node associated with the row. The costs of the associated sub-routes are stored in the “left-side” and “right-side” fields.
An example is helpful to illustrate what kind of data is stored in the intersection table of FIG. 10 . The intersection table shown in FIG. 10 has a three internode hop cost limit. Consider the row associated with node F. The “left-side” field includes an entry for end node A because there is a sub-route (i.e., either A-I-E-F or A-I-J-F) that is within the cost limit, that connects node A with node F and node A is on the lefthand side of the impacted trunk. An entry for node B is also on the “left-side” field because there is a sub-route that is within the cost limit, that interconnects nodes B and F (i.e., B-J-F), and end node B is on the lefthand side of the impacted trunk. Node C has an entry on the “right-side” field of this row because the sub-route (i.e., C-K-G-F) that interconnects node C with node F within the cost limit, and node C is on the righthand side of the impacted trunk.
Once the intersection table has been built for the impacted trunk, all sub-route intersections within the intersection table are identified (Step 504 in FIG. 5 ). An “intersection” is found in a row where there is an non-null entry in both the “left-side” and “right-side” fields. For the example intersection table shown in FIG. 10, the rows for nodes F, G, N and P include intersections.
The real time restoration process 208 checks whether an intersection is found in the intersection table (Step 506 in FIG. 5 ). If an intersection is found, the optimal intersection route is selected (Step 508 in FIG. 5 ). The optimal route is the one having the lowest cost. The selection of the route constitutes a selection or combination of the two end node pairs that intersect. For the example depicted in FIG. 10, the route comprising sub-routes A-F and C-F may be selected as a first option, or the route comprising sub-routes A-P and D-P may be selected. The pair of sub-routes having the lowest cost is the one that is selected. The restoral formed by combining the sub-routes is then employed, as will be described in more detail below relative to FIG. 9A and 9B (Step 510 in FIG. 5 ).
There may be instances in which the intersection table does not include any intersections (see Step 506 in FIG. 5 ). In such a case, a second series of analysis is performed (see Steps 512 and 514 in FIG. 5 ). FIG. 8 depicts the steps that are performed when a second series of analysis is performed. The second series of analysis entails folding out from the end nodes of sub-routes that result from the first series of analysis. Initially, the end node that was folded out from the lefthand in the first series is selected (Step 802 in FIG. 8 ). The selected end node is then folded out, and “left-side” entries are populated from the folding out on the second series intersection table (Step 804 in FIG. 8 ).
FIG. 11 shows an example of an intersection table that includes results of both a first and a second series of analyses. With the intersection table in FIG. 11, the cost limit is 2 internode hops rather than 3 internode hops in the intersection table in FIG. 10 . In the row for node F, the first series only includes a “left-side” entry for node B. The second series entries are for sub-routes that are at most two hops away from node F. Thus, node F (which is two nodes away from node K and interconnected by the sub-route K-G-F) is added to the “left-side” field for the second series of node K. This process is repeated for all the “left-side” end nodes beginning with Step 802 (see Step 806 in FIG. 8 ).
Similar steps are performed for end nodes of sub-routes that were folded out from righthand nodes in the first series. These end nodes are selected (Step 808 in FIG. 8) and folded out. The resulting “right-side” entries are populated in the intersection table. With respect to the example of row K in FIG. 11, nodes C, G and H are all end nodes for sub-routes that have two or less internodes hops from node K. This process is repeated until all of the “right-side” end nodes have been processed (see Step 812 in FIG. 8 ).
After the second series of analyses is performed (see FIG. 8 ), the resulting intersection table is processed as described above, beginning with Step 504 . If after the second series of analyses is performed, there is still no intersection found in Step 506 of FIG. 5, no restoral route is generated for the given trunk (Step 516 in FIG. 5 ). The processing may then resume at Step 326 of FIG. 3 with a new impacted trunk (if any).
FIGS. 9A and 9B show the steps that are performed to select a restoral route based upon intersections that have been found in an intersection table (i.e., Step 510 in FIG. 5 ). Initially, all the sub-routes for the “left-side” end node pairs of intersections in the intersection table are identified. For example, in the intersection table of FIG. 10, the sub-routes that extend between nodes A and F and nodes B and F are identified. The lowest cost route is selected (see Step 902 in FIG. 9 A). Sub-routes B-G, A-N and A-P are also identified. Sub-routes B-J-F and A-M-N have the lowest cost; one of them is selected. Other cost factors could be utilized to differentiate between such sub-routes that have a same internode hop cost.
The sub-route table is updated to decrement capacity for the selected lefthand sub-route (see 904 in FIG. 9 A). Since the selected sub-route is being utilized for restoral, the capacity occupied by the selected sub-route must be reflected in the sub-route table.
A check is then made whether the non-intersection end node for the lefthand sub-route that has been selected is on the originally impacted trunk (see 906 in FIG. 9 ). For example, if the selected intersection includes the sub-route A-I-E-F, node A is the non-intersection node. This process is equivalent to checking wherein the intersection was found from a second series in the intersection table. If the intersection was found in the second series, a non-intersection node will not be on the original impacted traffic trunk (Step 906 in FIG. 9 A).
In the instances where the non-intersection node of the lefthand sub-route is on the originally affected traffic trunk (see Step 906 in FIG. 9 A), all sub-routes for the “right-side” node pair of the intersection are identified and the sub-route with the lowest cost is selected (Step 914 in FIG. 9 B). Thus, if the sub-route between nodes B-J-F is chosen for the “left-side”, the sub-route C-K-G-F is selected from the “right-side.” The sub-route tables are then updated to reflect the use and capacity for the selected righthand sub-route (Step 916 in FIG. 9 B).
In Step 906 of FIG. 9A when it is determined that the non-intersection of the lefthand sub-route is on the originally affected traffic trunk (i.e., the intersection was found from the second series), the end node is not on the originally affected traffic trunk. An end node pair is selected from the non-intersection node under the first series (Step 908 in FIG. 9 A). This step is equivalent to selecting the end node pair from the first series fold out for the originally affected traffic trunk node. In the example network shown in FIG. 1, this process selects, the end node pair A-E from row E. In Step 910 of FIG. 9A, all sub-routes within the cost limits from this end node pair are identified, and the sub-route with the lowest cost is selected. The resulting use of capacity is reflected by updating the sub-route tables (Step 912 in FIG. 9 A).
A similar process is performed in Step 920 of FIG. 9B when it is determined in Step 918 of FIG. 9B that the non-intersection node is not on the righthand side of the originally affected traffic trunk. Specifically, an end node pair is selected from the non-intersection nodes row in the first series (Step 920 in FIG. 9 B). All sub-routes for the selected end node pairs are identified and the sub-route with the lowest cost is selected (Step 922 in FIG. 9 B). The sub-route tables are updated to reflect the decrease in capacity due to the selection of the lowest cost sub-route (Step 924 in FIG. 9 B). Lastly, selected sub-routes are combined to complete the restoral route (Step 926 in FIG. 9 B).
In an alternate embodiment of the present invention, the above-described approach is not used in a real time restoration system (i.e., a dynamic route generation restoration system) but rather is used in a pre-plan restoration system. FIG. 6 depicts the centralized restoration system 600 in this in this alternative embodiment. The centralized restoration system 600 communicates via data link 604 to restoration network device 602 , such as described above. The centralized restoration system 600 communicates with a mainframe-based provisioning system 606 comprising network topology database 616 . A local copy 614 of the network topology database is downloaded into the centralized restoration system 600 . A pre-plan restoration process 608 communicates with the restoration network device 602 over a network device interface 610 . The pre-plan restoration process 608 builds and has access to an intersection table 618 and a restoration database 612 that includes other tables. A pre-plan database 626 is provided to bold pre-plans that are used in restoring the network.
FIG. 12 depicts the steps that are performed in this alternate embodiment. Initially, the sub-route tables are built (Step 308 in FIG. 12 ). As has been described above relative to FIG. 4, the traffic trunks that are affected by the network outage are identified and prioritized (Step 1202 in FIG. 12 ). The affected traffic trunks are processed in sequence with the selection of the highest priority traffic initially (Step 1204 in FIG. 12 ). A failure span is selected along the selected traffic trunk (Step 1206 in FIG. 12 ). Sub-routes that traverse the impacted section of the network are excluded (Step 310 in FIG. 12 ). A restoral route is generated using the pre-plans in accordance with the steps depicted in FIG. 5 (Step 314 in FIG. 12 ). The actions are created to realize the restoral (Step 316 in FIG. 12 ). The actions are stored as a pre-plan in the pre-plan database 626 (Step 1208 in FIG. 12 ). If all of the failure spans have been selected (see Step 1210 in FIG. 12 ), the pre-plan restoration process checks whether all traffic trunks have been selected (Step 1212 in FIG. 12 ). After all traffic trunks have been selected, the process is completed. If the all traffic trunks have not been selected, the process begins again starting at Step 1204 with a new traffic trunk. If all the failure spans within the traffic trunks have not been selected, the process is repeated beginning at Step 1206 .
While the present invention has been described with reference to an illustrative embodiment thereof, those skilled in the art will appreciate the various changes in form and detail may be made without departing from the intended scope of the present invention as defined in the appended claims.
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A restoral route generation process combines elements of a pre-plan methodology with a dynamic route generation methodology. The resulting hybrid approach quickly produces a restoral route in real time that has a minimal associated cost. The hybrid approach pre-generates sub-routes that are combined to produce a restoral route. The combining of the sub-routes takes place dynamically in response to a network failure. The hybrid approach may interactively operate to generate restoral routes for each trunk in the network that is affected by an outage.
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FIELD OF THE INVENTION
[0001] The present invention relates to a spark plug for an internal combustion engine.
BACKGROUND OF THE INVENTION
[0002] A spark plug for providing ignition in an internal combustion engine, such as a gasoline engine, has the following structure: an insulator is provided externally of a center electrode; a metallic shell (main metal fitting) is provided externally of the insulator; and a ground electrode which forms a spark discharge gap in cooperation with the center electrode is attached to the metallic shell. The metallic shell is generally formed from an iron-based material, such as carbon steel, and, in many cases, plating is performed on its surface for corrosion protection. A known technique for performing such plating forms a plating layer having a 2-layer structure consisting of an Ni plating layer and a chromate layer (Japanese Patent Application Laid-Open (kokai) No. 2002-184552, “Patent Document 1”).
Problems to be Solved by the Invention
[0003] According to the technique for forming a plating layer having 2-layer structure, a plating process is performed before a crimping process. In the crimping process, an insulator to which a center electrode is attached is inserted into a hollow portion of a hollow, cylindrical metallic shell; then, a portion of the metallic shell is crimped inward (toward the insulator), thereby fixing the metallic shell to the insulator. This crimping process has involved a problem in which an associated deformation of the metallic shell causes cracking or peeling of the plating layer, resulting in deterioration in salt corrosion resistance. Also, the crimping process has involved the following problem: because of residual stress in the metallic shell stemming from the crimping process or an increase in hardness the metallic shell associated with a microstructural change caused by heating in hot crimping, stress corrosion cracking arises in a portion which has high hardness and where a large residual stress exists. However, conventionally, sufficient measures have not been devised for attaining a spark plug superior in salt corrosion resistance and stress corrosion cracking resistance.
[0004] An object of the present invention is to provide a spark plug superior in salt corrosion resistance and stress corrosion cracking resistance.
SUMMARY OF THE INVENTION
Means for Solving the Problems
[0005] The present invention has been conceived to solve, at least partially, the above problems and can be embodied in the following modes or application examples.
[0006] [Application example 1] A spark plug comprising a metallic shell coated with a composite layer which includes a nickel plating layer and a chromate layer formed on the nickel plating layer, characterized in that the nickel plating layer has a thickness A which satisfies a relational expression 3μm≦A≦15 μm and that the chromate layer has a thickness B which satisfies a relational expression 2 nm≦B≦45 nm.
[0007] [Application example 2] A spark plug described in application example 1, wherein the thickness B satisfies a relational expression 20 nm≦B≦45 nm.
[0008] [Application example 3] A spark plug described in application example 2, wherein the thickness A satisfies a relational expression 5 μm≦A≦15 μm.
[0009] [Application example 4] A metallic shell for a spark plug, coated with a composite layer which includes a nickel plating layer and a chromate layer formed on the nickel plating layer, characterized in that the nickel plating layer has a thickness A which satisfies a relational expression 3μm≦A≦15 μm and that the chromate layer has a thickness B which satisfies a relational expression 2 nm≦B≦45 nm.
[0010] The present invention can be implemented in various forms. For example, the present invention can be implemented in a method of manufacturing a spark plug and a method of manufacturing a metallic shell.
Effects of the Invention
[0011] In the spark plug of application example 1, since the thickness A of the nickel plating layer of the metallic shell is not less than 3 μm, there can be restrained the formation of a plating-repellant portion (pinhole) which could otherwise result from a situation in which oil or the like that has adhered to the surface of the metallic shell before formation of the nickel plating layer remains incompletely removed due to insufficient cleaning, whereby salt corrosion resistance can be enhanced. Additionally, since the thickness A of the nickel plating layer is not greater than 15 μm, there can be restrained cracking of the nickel plating layer which could otherwise result from a large thickness, whereby plating peeling resistance can be enhanced. Therefore, salt corrosion resistance can be enhanced. Also, since a thickness range smaller than a relatively small thickness of 2 nm is excluded for the thickness B of the chromate layer, there can be restrained a fracture of the chromate layer which could otherwise result from residual stress associated with crimping. Additionally, since thickness range greater than a relatively large thickness of 45 nm is excluded for the thickness B of the chromate layer, there can be restrained the occurrence of cracking during working which could otherwise result from poor adhesion to the metallic shell (the nickel plating layer). Therefore, stress corrosion cracking resistance can be enhanced. Thus, a spark plug superior in salt corrosion resistance and stress corrosion cracking resistance can be provided.
[0012] Employment of the configuration of application example 2 can further enhance stress corrosion cracking resistance.
[0013] Employment of the configuration of application example 3 can further enhance plating peeling resistance and salt corrosion resistance.
[0014] In the metallic shell of application example 4, since the thickness A of the nickel plating layer is not less than 3 μm, there can be restrained the formation of a plating-repellant portion (pinhole) which could otherwise result from a situation in which oil or the like that has adhered to the surface of the metallic shell before formation of the nickel plating layer remains incompletely removed due to insufficient cleaning, whereby salt corrosion resistance can be enhanced. Additionally, since the thickness A of the nickel plating layer is not greater than 15 μm, there can be restrained cracking of the nickel plating layer which could otherwise result from a large thickness, whereby plating peeling resistance can be enhanced. Therefore, salt corrosion resistance can be enhanced. Also, since a thickness range smaller than a relatively small thickness of 2 nm is excluded for the thickness B of the chromate layer, there can be restrained a fracture of the chromate layer which could otherwise result from residual stress associated with crimping. Additionally, since a thickness range greater than a relatively large thickness of 45 nm is excluded for the thickness B of the chromate layer, there can be restrained the occurrence of cracking during working which could otherwise result from poor adhesion to the metallic shell (the nickel plating layer). Therefore, stress corrosion cracking resistance can be enhanced. Thus, by use of the metallic shell of application example 4, a spark plug superior in salt corrosion resistance and stress corrosion cracking resistance can be provided.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is a sectional view of essential members, showing the structure of a spark plug according to an embodiment of the present invention.
[0016] FIG. 2 is an explanatory view showing an example step of fixing a metallic shell 1 to an insulator 2 through crimping.
[0017] FIG. 3 is a flowchart showing the procedure of the plating process for the metallic shell.
[0018] FIGS. 4( a ) and 4 ( b ) are explanatory views showing the results of tests for plating peeling resistance, salt corrosion resistance, and stress corrosion cracking resistance with respect to 49 samples S 1 to S 49 prepared under the above-mentioned processing conditions.
DETAILED DESCRIPTION OF THE INVENTION
[0019] A. Configuration of spark plug: FIG. 1 is a sectional view of essential members, showing the structure of a spark plug according to an embodiment of the present invention. A spark plug 100 includes a tubular metallic shell 1 ; a tubular insulator 2 , which is fitted into the metallic shell 1 in such a manner that its forward end portion projects from the metallic shell 1 ; a center electrode 3 , which is provided in the insulator 2 in such a state that its forward end portion projects from the insulator 2 ; and a ground electrode 4 whose one end is joined to the metallic shell 1 and whose other end faces the forward end of the center electrode 3 . A spark discharge gap g is formed between the ground electrode 4 and the center electrode 3 .
[0020] The insulator 2 is formed from, for example, a ceramic sintered body of alumina or aluminum nitride and has a through hole 6 formed therein in such a manner as to extend along the axial direction thereof, and adapted to allow the center electrode 3 to be fitted therein. A metal terminal 13 is fixedly inserted into the through hole 6 at a side toward one end of the through hole 6 , whereas the center electrode 3 is fixedly inserted into the through hole 6 at a side toward the other end of the through hole 6 . A resistor 15 is disposed, within the through hole 6 , between the metal terminal 13 and the center electrode 3 . Opposite end portions of the resistor 15 are electrically connected to the center electrode 3 and the metal terminal 13 via electrically conductive glass seal layers 16 and 17 , respectively.
[0021] The metallic shell 1 is formed into a hollow, cylindrical shape from a metal, such as carbon steel, and forms a housing of the spark plug 100 . The metallic shell 1 has a threaded portion 7 formed on its outer circumferential surface and adapted to mount the spark plug 100 to an unillustrated engine block. A hexagonal portion 1 e is a tool engagement portion which allows a tool, such as a spanner or a wrench, to be engaged therewith in mounting the metallic shell 1 to the engine block, and has a hexagonal cross section. In a space between the outer surface of the insulator 2 and the inner surface of a rear (upper in the drawing) opening portion of the metallic shell 1 , a ring packing 62 is disposed on the rear periphery of a flange-like projection 2 e of the insulator 2 , and a filler layer 61 , such as talc, and a ring packing 60 are disposed, in this order, rearward of the ring packing 62 . In assembling work, the insulator 2 is pressed forward (downward in the drawing) into the metallic shell 1 , and, in this condition, the rear opening end of the metallic shell 1 is crimped inward toward the ring packing 60 (and, in turn, toward the projection 2 e , which functions as a receiving portion for crimping), whereby a crimp portion 1 d is formed, and thus the metallic shell 1 is fixed to the insulator 2 .
[0022] A gasket 30 is fitted to a proximal end of the threaded portion 7 of the metallic shell 1 . The gasket 30 is formed by bending a metal sheet of carbon steel or the like into the form of a ring. When the threaded portion 7 is screwed into a threaded hole of the cylinder head, the gasket 30 is compressed in the axial direction and deformed in a crushed manner between a flange-like gas seal portion 1 f of the metallic shell 1 and a peripheral-portion-around-opening of the threaded hole, thereby sealing the gap between the threaded hole and the threaded portion 7 .
[0023] FIG. 2 is an explanatory view showing an example step of fixing the metallic shell 1 to the insulator 2 through crimping. FIG. 2 omits the illustration of the ground electrode 4 . First, as shown in FIG. 2( b ), the insulator 2 whose through hole 6 accommodates the center electrode 3 , the electrically conductive glass seal layers 16 and 17 , the resistor 15 , and the metal terminal 13 is inserted into the metallic shell 1 shown in FIG. 2( a ) from an insertion opening portion 1 p (where a prospective crimp portion 200 which will become the crimp portion 1 d is formed) at the rear end of the metallic shell 1 , thereby establishing a state in which an engagement portion 2 h of the insulator 2 and an engagement portion 1 c of the metallic shell 1 are engaged together via a sheet packing 63 .
[0024] Then, as shown in FIG. 2( c ), the ring packing 62 is disposed inside the metallic shell 1 through the insertion opening portion 1 p; subsequently, the filler layer 61 of talc or the like is formed; and, furthermore, the ring packing 60 is disposed. Then, by means of a crimping die 111 , the prospective crimp portion 200 is crimped to an end surface 2 n of the projection 2 e, which functions as a receiving portion for crimping, via the ring packing 62 , the filler layer 61 , and the ring packing 60 , thereby forming the crimp portion 1 d and fixing the metallic shell 1 to the insulator 2 through crimping as shown in FIG. 2( d ). At this time, in addition to the crimp portion 1 d , a groove portion 1 h ( FIG. 1) located between the hexagonal portion 1 e and the gas seal portion 1 f is also deformed under a compressive stress associated with crimping. The reason for this is that the crimp portion 1 d and the groove portion 1 h are thinnest portions in the metallic shell 1 . The groove portion 1 h is also called the “thin-walled portion.” After the step of FIG. 2 d ), the ground electrode 4 is bent toward the center electrode 3 so as to form the spark discharge gap g, thereby completing the spark plug 100 of FIG. 1 . The crimping step described with reference to FIG. 2 is of cold crimping; however, hot crimping can also be employed.
[0025] B. Plating process: In manufacture of the spark plug 100 , before the above-mentioned crimping step, a plating process is performed on the metallic shell 1 . FIG. 3 is a flowchart showing the procedure for the plating process for the metallic shell. In step T 100 , nickel strike plating is performed. Nickel strike plating is performed for cleaning the surface of the metallic shell formed from carbon steel and for improving adhesion between plating and a base metal. However, nickel strike plating may be omitted. Usually employed processing conditions can be employed for nickel strike plating. A specific example of preferable processing conditions is as follows.
[0026] <Example of Processing Conditions of Nickel Strike Plating>
[0000] Composition of plating bath
Nickel chloride: 150-600 g/L 35% hydrochloric acid: 50-300 ml/L Solvent: Deionized water
Processing temperature (bath temperature): 25-40° C.
Cathode current density: 0.2-0.4 A/dm 2
Processing time; 5-20 minutes
[0030] In step T 110 , an electrolytic nickel plating process is performed. The electrolytic nickel plating process can be a barrel-type electrolytic nickel plating process which uses a rotary barrel, and may employ another plating method, such as a stationary plating method. Usually employed processing conditions can be employed for electrolytic nickel plating. A specific example of preferable processing conditions is as follows.
[0031] <Example of Processing Conditions of Electrolytic Nickel Plating>
[0000] Composition of plating bath
Nickel sulfate: 100-400 g/L Nickel chloride: 20-60 g/L Boric acid: 20-60 g/L Solvent: Deionized water
Bath pH: 2.0-4.8
[0036] Processing temperature (bath temperature): 25-60° C.
Cathode current density: 0.2-0.4 A/dm 2
Processing time: 24-192 minutes
[0037] In step T 120 , an electrolytic chromating process is performed. The electrolytic chromating process can also use a rotary barrel and may employ another plating method, such as a stationary plating method. An example of preferable processing conditions of the electrolytic chromating process is as follows.
[0038] <Example of Processing Conditions of Electrolytic Chromating Process>
[0000] Composition of processing bath (chromating processing solution)
Sodium dichromate: 20-70 g/L Solvent: Deionized water
Bath pH: 2-6
[0041] Processing temperature (bath temperature): 20-60° C.
Cathode current density: 0.01-0.50 A/dm 2 (preferably 0.02-0.45 A/dm 2 )
Processing time: 1-10 minutes
[0042] A usable dichromate other than sodium dichromate is potassium dichromate. Another combination of processing conditions (amount of dichromate, cathode current density, processing time, etc.) different from the above may be employed according to a desired thickness of the chromate layer.
[0043] By performing the above plating processes, a film of 2-layer structure consisting of the nickel plating layer and the chromate layer is formed on the outer and inner surfaces of the metallic shell. Another protection film can be formed on the film of 2-layer structure. For example, there can be formed a film of seizure inhibitor which contains C (mineral oil or graphite) and one or more components selected from among Al, Ni, Zn, and Cu. Through formation of a seizure inhibitor film, when the engine head is heated to a high temperature, there can be restrained seizure between the spark plug and the engine head. Also, for example, there can be formed a film of rust prevention oil which contains at least one of C, Ba, Ca, and Na. After a multilayered protection film is formed as mentioned above, the metallic shell is fixed to the insulator, etc., by the crimping step, thereby completing the spark plug.
C. EXAMPLE
C1. Processing Conditions:
[0044] The metallic shells 1 were manufactured, by cold forging, from a carbon steel wire SWCH17K for cold forging specified in JIS G3539. The ground electrodes 4 were welded to the respective metallic shells 1 , followed by degreasing and water washing. Subsequently, a nickel strike plating process was performed under the following processing conditions by use of a rotary barrel.
[0045] <Processing Conditions of Nickel Strike Plating>
[0000] Composition of plating bath
Nickel chloride: 300 g/L 35% hydrochloric acid: 100 ml/L
Processing temperature (bath temperature): 30±5° C.
Cathode current density: 0.3 A/dm 2
Processing time: 15 minutes
[0048] Next, an electrolytic nickel plating process was performed under the following processing conditions by use of the rotary barrel, thereby forming nickel plating layers. The nickel (Ni) content (% by mass) of the nickel plating layers was 98% or higher.
[0049] <Processing Conditions of Electrolytic Nickel Plating>
[0000] Composition of plating bath
Nickel sulfate: 250 g/L Nickel chloride: 50 g/L Boric acid: 40 g/L
Bath pH: 4.0
[0053] Processing temperature (bath temperature): 55±5° C.
Cathode current density: 0.3 A/dm 2
Processing time: 24-192 minutes
[0054] In the present example, there were prepared seven types of samples which differed in the thickness of the nickel plating layer as effected through control of the thickness of the nickel plating layer by means of the processing time of plating. Specifically, there were prepared seven types of samples which differed in the thickness of the nickel plating layer as effected by means of the following seven types of processing time. “The thickness of the nickel plating layer” means the total thickness of the thickness of a layer formed by the above-mentioned nickel strike plating process and the thickness of a layer formed by the above-mentioned electrolytic nickel plating process.
[0000] Processing time: 24 minutes
Nickel plating layer thickness: 2 μm
Processing time: 36 minutes
Nickel plating layer thickness: 3 μm
Processing time: 48 minutes
Nickel plating layer thickness: 4 μm
Processing time: 60 minutes
Nickel plating layer thickness: 5 μm
Processing time: 108 minutes
Nickel plating layer thickness: 9 μm
Processing time; 180 minutes
Nickel plating layer thickness: 15 μm
Processing time: 192 minutes
Nickel plating layer thickness: 16 μm
[0062] The relationship between processing time and the thickness of the nickel plating layer was experimentally obtained beforehand. The thickness of the nickel plating layer was measured by use of a fluorescent X-ray film thickness meter under the following conditions: beam diameter of X ray: 0.2 mm; and radiation time: 10 seconds.
[0063] Next, an electrolytic chromating process was performed by use of a rotary barrel under the following processing conditions, thereby forming a chromate layer on the nickel plating layer.
[0064] <Processing Conditions of Electrolytic Chromating Process>
[0000] Composition of processing bath (chromating processing solution)
Sodium dichromate: 40 g/L Solvent: Deionized water
Processing temperature (bath temperature): 35±5° C.
Cathode current density: 0.01 A/dm 2 -0.50 A/dm 2
Processing time: 5 minutes
[0067] In the present embodiment, there were prepared seven types of samples which differed in the thickness of the chromate layer as effected through control of the thickness of the chromate layer by means of the cathode current density. Specifically, there were prepared seven types of samples which differed in the thickness of the chromate layer as effected by means of the following seven types of cathode current density.
[0000] Cathode current density: 0.01 A/dm 2
Chromate layer thickness: 1 nm
Cathode current density: 0.02 A/dm 2
Chromate layer thickness: 2 nm
Cathode current density: 0.10 A/dm 2
Chromate layer thickness: 10 nm
Cathode current density: 0.20 A/dm 2
Chromate layer thickness: 20 nm
Cathode current density: 0.40 A/dm 2
Chromate layer thickness: 40 nm
Cathode current density: 0.45 A/dm 2
Chromate layer thickness: 45 nm
Cathode current density: 0.50 A/dm 2
Chromate layer thickness: 50 nm
[0075] The relationship between cathode current density and the thickness of the chromate layer was experimentally obtained beforehand. The thickness of the chromate layer was measured as follows. First, a small specimen was cut out from near the outer surface of each of the samples by use of a focused iron beam machining apparatus (FIB machining apparatus). Then, by use of a scanning transmission electron microscope (STEM), the small specimen was analyzed at an acceleration voltage of 200 kV, thereby obtaining a color map image of Cr elements with respect to the vicinity of the outer surface on a cross section (a section perpendicular to the center axis represented by the dot-dash line in FIG. 1 ) of the metallic shell. From this color map image, the thickness of the chromate layer was measured.
[0076] There were prepared 49 (7 types×7 types) metallic shell samples (S 1 to S 49 ) which differed in the thickness of the nickel plating layer and in the thickness of the chromate layer as effected through processing under the above-mentioned conditions. The samples S 1 to S 49 were tested for evaluation of salt corrosion resistance, plating peeling resistance, and stress corrosion cracking resistance.
C2. Evaluation Test Conditions:
[0077] <Salt Corrosion Resistance Test>
[0078] The neutral salt spray test specified in JIS H8502 was conducted for evaluation of salt corrosion resistance. In this test, after a 48-hour salt spray test, there was measured the percentage of a red-rusted area to the surface area of the metallic shell of a sample. The percentage of a red-rusted area was calculated as follows: a sample after the test was photographed; there were measured a red-rusted area Sa in the photograph and an area Sb of the metallic shell in the photograph; and the ratio Sa/Sb was calculated, thereby obtaining the percentage of the red-rusted area.
[0079] <Plating Peeling Resistance Test>
[0080] The evaluation test for plating peeling resistance was conducted as follows. After the metallic shells of the samples underwent a chromating process, the insulators, etc., were fixed by crimping. Subsequently, the crimp portions 1 d were inspected for a state of plating to see if lifting or peeling of plating was present.
[0081] <Stress Corrosion Cracking Resistance Test>
[0082] In order to evaluate stress corrosion cracking resistance, the following accelerated corrosion test was conducted. Four holes each having a diameter of about 2 mm were cut in the groove portions 1 h ( FIG. 1 ) of the samples (metallic shells); subsequently, the insulators, etc., were fixed by crimping. The holes were cut for allowing entry of a corrosive solution for test into the metallic shells. The test conditions of the accelerated corrosion test are as follows.
[0083] [Test Conditions of Accelerated Corrosion Test (Stress Corrosion Cracking Resistance Test)]
[0000] Composition of corrosive solution
Calcium nitrate tetrahydrate: 1,036 g Ammonium nitrate: 36 g Potassium permanganate: 12 g Pure water: 116 g
pH: 3.5-4.5
Processing temperature: 30-40° C.
[0088] The reason for adding potassium permanganate as an oxidizer into the corrosive solution is to accelerate the corrosion test.
[0089] After the 10-hour test under the above-mentioned test conditions, the samples were taken out from the corrosive solution. Then, the groove portions 1 h of the samples were externally examined by use of a magnifier to see if cracking was generated in the groove portions 1 h . When the samples were found to be free from cracking, the corrosive solution was replaced with a new one; then, the samples underwent the accelerated corrosion test under the same conditions for another 10 hours. The test was repeated until the cumulative test time reached 80 hours. As a result of the crimping step, a large residual stress is generated in the groove portions 1 h . Therefore, by means of the accelerated corrosion test, the groove portions 1 h can be evaluated for stress corrosion cracking resistance.
C3. Test Results:
[0090] FIGS. 4( a ) and 4 ( b ) are explanatory views showing the results of tests for plating peeling resistance, salt corrosion resistance, and stress corrosion cracking resistance with respect to 49 samples S 1 to S 49 prepared under the above-mentioned processing conditions.
[0091] As shown in FIGS. 4( a ) and 4 ( b ), regarding plating peeling resistance, substantially the same results were yielded in all thickness cases of the chromate layer. Specifically, in all thickness cases of the chromate layer, lifting or peeling of plating did not arise at a nickel plating layer thickness of 2 μm to 15 μm; however, lifting or peeling of plating arose at a nickel plating layer thickness of 16 μm (samples S 7 , S 14 , S 21 , S 28 , S 35 , S 42 , and S 49 ). Therefore, in view of plating peeling resistance, preferably, the nickel plating layer has a thickness of 2 μm to 15 μm. Conceivably, this is for the following reason: when the nickel plating layer has an excessively large thickness, the plating layer is apt to crack even under a small stress.
[0092] Regarding salt corrosion resistance, substantially the same results were yielded in all thickness cases of the chromate layer. Specifically, in all thickness cases of the chromate layer, the formation of red rust was restrained to 10% or less at a nickel plating layer thickness of 3 μm to 16 μm; however, the formation of red rust exceeded 10% at a nickel plating layer thickness of 2 μm (samples S 2 , S 8 , S 15 , S 22 , S 29 , S 36 , and S 43 ). Therefore, in view of salt corrosion resistance, preferably, the nickel plating layer has a thickness of 3 μm to 16 μm. Conceivably, this is for the following reason: when the nickel plating layer has an excessively small thickness, a plating-repellant portion (pinhole) is formed from a situation in which oil, stain, or the like that has adhered to the surface of the metallic shell remains incompletely removed due to insufficient cleaning; consequently, rust is formed at and propagates from such a portion.
[0093] Regarding stress corrosion cracking resistance, substantially the same results were yielded in all thickness cases of the nickel plating layer. Specifically, in all thickness cases of the nickel plating layer, cracking was not generated in the groove portion 1 h at a chromate layer thickness of 2 nm to 45 nm at a cumulative test time of 20 hours or less; however, cracking was generated in the groove portion 1 h at a chromate layer thickness of 1 nm (samples S 1 to S 7 ) and 50 nm (samples S 43 to S 49 ) at a cumulative test time of 20 hours or less. Therefore, in view of stress corrosion cracking resistance, preferably, the chromate layer has a thickness of 2 nm to 45 nm. More preferably, the chromate film has a thickness of 20 nm to 45 nm (samples S 22 to S 42 ), since cracking is not generated at a cumulative test time of 80 hours or less.
[0094] In the case where the chromate layer has a small thickness (1 nm), stress corrosion cracking resistance is poor, conceivably, for the following reason: since the chromate layer is excessively thin, the chromate layer is apt to be destroyed by residual stress. In the case where the chromate layer has a large thickness (50 nm), stress corrosion cracking resistance is poor, conceivably, for the following reason: since the chromate layer is thick, adhesion to the metallic shell deteriorates; consequently, cracking is apt to arise in the course of working, such as crimping.
[0095] According to comprehensive evaluation of the above test results regarding plating peeling resistance, salt corrosion resistance, and stress corrosion cracking resistance, most preferably, the nickel plating layer has a thickness of 5 μm to 15 μm, and the chromate layer has a thickness of 20 nm to 45 nm. The samples S 25 to S 27 , S 32 to S 34 , and S 39 to S 41 which satisfy these conditions have made the best marks in all the tests.
DESCRIPTION OF REFERENCE NUMERALS
[0000]
1 : metallic shell
1 c : engagement portion
1 d : crimp portion
1 e : hexagonal portion
1 f : gas seal portion (flange portion)
1 h : groove portion (thin-walled portion)
1 p : insertion opening portion
2 : insulator
2 e : projection
2 h : engagement portion
2 n : end surface
3 : center electrode
4 : ground electrode
6 : through hole
7 : threaded portion
13 : metal terminal
15 : resistor
16 , 17 : electrically conductive glass seal layer
30 : gasket
60 : ring packing
61 : filler layer
62 : ring packing
63 : sheet packing
100 : spark plug
111 : die
200 : prospective crimp portion
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A spark plug superior in salt corrosion resistance and stress corrosion cracking resistance is provided. The park plug includes a metallic shell coated with a composite layer which includes a nickel plating layer and a chromate layer formed on the nickel plating layer. The spark plug is characterized in that the nickel plating layer has a thickness A which satisfies a relational expression 3 μm≦A≦15 μm and that the chromate layer has a thickness B which satisfies a relational expression 2 nm≦B≦45 nm.
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FIELD OF THE INVENTION
The invention relates to a dispenser, and more particularly, to a device for dispensing a hygienic liquid into the nasal and sinus cavities for cleansing and flushing. In addition, the device is one which will dispense only in a unidirectional path, dispensing only the liquid within the receptacle and not permitting any contaminated liquid to re-enter the receptacle for further dispensing.
DESCRIPTION OF THE ART
Although there are many types of spray devices utilized for use with respect to the nose for spraying the nasal and sinus cavities, there is none which will prevent a return of any contaminated liquid to the receptacle. The liquid usually sprayed into the nose runs out and carries germs and residue therewith, which can re-enter the receptacle via the spray tip within the nostril, thereby contaminating the liquid within the receptacle. This return of the liquid already dispensed from the receptacle results in the liquid being a contaminate rather than an hygienic liquid. There is also no way in which the present dispensers can be washed or disinfected so the liquid is always certain to be hygienic with no contamination. Consequently, it can be said that the devices currently in use as a spray dispensing device in no way permits the hygienic liquid to be protected against re-contamination. In the device disclosed hereinafter all parts of the system are easily removable for cleaning and disinfecting and/or sterilizing. The nasal occluder is easily removed following each use and can be washed and dried for subsequent use. Other features are noted hereinafter which will distinguish the advantages of the present device as compared to those now in use. Clearly, the components of the device composing the invention are such that in combination they provide for a leak-proof device that can be readily utilized under most any conditions.
SUMMARY OF THE INVENTION
The present invention is concerned with a device for hygienically cleaning and flushing the nasal and sinus passages with a liquid contained in a pliant receptacle having an open end. An intermediate member is releasably attached to the receptacle at its open end for closing and sealing the end and into which an occluder can also be releasably attached at the other end, the occluder being readily insertable into one of the nostrils of the nose. The receptacle, per se, is of a pliant plastic material which permits the user to squeeze the bottle in order to eject and provide a flow of the liquid from the receptacle through the intermediate member, through the occluder and into the nose. Control means associated with either the intermediate member or the occluder permits and maintains a flow of the liquid only as long as the pliant receptacle is deformed and only in a direction to discharge the liquid from the occluder to the nostril.
The intermediate member is provided with a liquid passageway extending from one end of the member within the receptacle to the other end without the intermediate member. A second liquid passageway in the occluder is co-extensive with that of the intermediate member and directs the liquid to the nostril in which the occluder has been inserted. In the passageway of either the intermediate member or the occluder an anti-retractive device is inserted to control the direction of flow of the liquid from the receptacle to the nostril when the plaint receptacle is deformed by squeezing. With such a control member, the liquid flows. unidirectionally to the occluder and hence to the nostril. Upon release of the pressure applied to the receptacle, the receptacle returns to its original state by the entry of air into the receptacle through a breathing hole in which there is also an anti-retractive device or check valve. With the entry of air into the receptacle via the check valve, the air pressure within the receptacle becomes the same as the atmospheric pressure outside of the receptacle. In this way, the receptacle quickly returns to its original shape and is immediately ready for another deformation to dispense another stream of liquid without sucking in any of the already dispensed liquid. It has been found that with a device of this type which can be readily disassembled for cleaning and disinfecting, a health standard is acquired that is not heretofore possible with other types of dispensers utilized for the same purpose.
SUMMARY OF THE INVENTION
The primary object of the invention is to provide a device for hygienically cleaning and flushing the nasal and sinus passages with a liquid contained in a pliant receptacle and having a unidirectional flow.
A further object of the invention is to provide a liquid dispensing device in which the elements of the device can be readily disassembled, cleaned and disinfected for future use and which, when used, alleviates any possibility of contamination of the hygienic liquid in the receptacle by any liquid already dispensed.
Another object of the invention is to provide a liquid dispensing device in which the pressure within the receptacle for the hygienic liquid is always at a level with that of the atmospheric pressure to guarantee a unidirectional flow of the liquid upon deformation of the pliant receptacle.
Still another object of the invention is to provide a liquid dispensing device for hygienically cleaning and flushing the nasal and sinus passages with a liquid contained in a pliant receptacle in which a minimum number of parts are utilized and which permits easy disassembling of the device for cleaning and disinfecting, and/or sterilizing after each use.
These and other objects and advantages of the invention will be apparent to those skilled in the art by the description which follows.
DESCRIPTION OF THE DRAWINGS
Reference is now made to the accompanying drawings wherein like reference numerals and characters designate like parts and wherein:
FIG. 1 is an elevational view of a liquid dispenser in accordance with the invention and incorporating the elements required to provide a dispenser which is capable of a unidirectional flow of the liquid contained therein;
FIG. 2 is a vertical section through the elements attached to and forming a part of the dispenser associated with the open end thereof for sealing the end and for providing a unidirectional flow of the liquid;
FIG. 3 is a plan view of the intermediate member taken substantially along the line 3--3 of FIG. 2 and showing the elements comprising the liquid and the air passageways for maintaining the receptacle at a pressure uniform with that of the atmosphere;
FIG. 4 is a vertical section through the intermediate member and similar to that shown in FIG. 2 for disclosing another embodiment of the invention with a different type of anti-retractive check valve;
FIG. 5 is a plan view of the intermediate member showing primarily the arrangement of a different relation of the liquid and air passageways in the intermediate member for use with a different type of anti-retractive check valves;
FIG. 6 is a perspective view of an anti-retractive check valve such as shown in FIG. 4, in which the valve assumes a closed position when there is no pressure difference on the two sides of the valve; and
FIG. 7 is a perspective view similar to FIG. 6 showing the way in which the anti-retractive check valve opens when a pressure difference is induced on the two sides of the valve.
DESCRIPTION OF PREFERRED EMBODIMENTS
With respect to FIG. 1 in particular, the device 10, according to the invention, comprises a pliant receptacle 11, an intermediate member 12 and an occluder 13. These are the primary elements, each of which will be defined and described in more detail hereinafter.
The receptacle 11 is preferably a very pliant plastic material which can be readily deformed upon squeezing so as to move or flush a liquid within the receptacle toward the intermediate member 12 and the occluder 13. As is well known, such a receptacle can take the form of a bottle or similar shape with an open end 14 that is provided with a threaded portion 15 for receiving a cap 16.
The intermediate member 12 is shown in more detail in FIG. 2. In this disclosure the member 12 comprises a portion 17 which extends into the open end 14 of the receptacle and is provided with a shoulder 18 for engaging an O-ring 19 arranged between the shoulder and the end of the threaded portion 15 of the receptacle 11. As shown in this FIG. 2, the cap 16 upon being threaded onto the portion 15 compresses the O-ring 19 between the neck of the bottle and the shoulder 18 to seal the receptacle thereby providing a closure which prevents any leakage of the liquid within the receptacle. Also, the portion 17 is provided with a counterbore 20 for receiving an end of a plastic tube 21 that extends into the liquid within the receptacle for directing the liquid to the intermediate member 12. In connection with the counterbore 20, a small aperture 22 connects the counterbore 20 to a chamber 23 in which there is arranged a stainless steel ball 24 which is seated against a small O-ring 25 within the chamber and adjacent to the aperture 22 by a spring 26. The end 27 of the member 12 that is without the open end 14 of the receptacle 11 is provided with a counterbore 28 that is coextensive with counterbore 20, aperture 22 and chamber 23 for receiving the extension 29 of the occluder 13. The occluder 13 is provided with a central aperture 30 that is coextensive with the chamber 23 when the extension 29 is inserted in the counterbore 28, thereby providing an exit for the liquid from the other end of the chamber 23.
Also associated with the intermediate member 12 is a vertical opening 32 which provides a passageway for air via a slot 33 between opening 32 and a chamber 34. The chamber 34 is connected via an aperture 35 to an air entry opening 36. With this arrangement, this series of opening 36, aperture 35, chamber 34, slot 33, and the vertical opening 32 provide an air passageway connecting the atmosphere with the interior of the receptacle 11. In the chamber 34, as in chamber 23, there is also arranged a ball 37 which, as previously described with respect to the chamber 23, is biased against an O-ring 38 by spring 39 to provide a cut-off of any air flow from the atmosphere to the interior of the receptacle under normal conditions. It will be noted that the outer end of the intermediate member 12 carries a plate 40 having an aperture 41 for permitting the extension 29 of the occluder 13 to be inserted in the counterbore 28. The plate 40 seals the end of member 12 and can be provided with an extension or nib 42 for engaging and/or centering the spring 39 within the chamber 34. With the arrangement of the springs 26, 39 and balls 24, 37 within the respective chambers 23 and 34 an anti-retractive check valve is provided in each of the liquid and air passageways.
The occluder 13 is of a shape and size to permit entry of the bulb-shaped portion 44 into the nostril so the liquid dispensed from the receptacle can be forced or circulated into the nasal and sinus cavities. The liquid passageway 30 of the occluder 13 is coextensive with chamber 23 and is shown as terminating in a single aperture at the very end of portion 44. As an alternative a series of small holes can be provided so that a flow in the form of a spray can be utilized rather than a direct stream as shown in FIG. 2.
In the operation of the device 10, the receptacle is first filled with a saline solution or a prescribed liquid for cleansing and flushing the sinus and nasal cavities. The intermediate member is then inserted in the open end 14 of the receptacle 11, thereby sealing the open end when the cap 16 seats the shoulder 18 of the intermediate member against the O-ring 19. A liquid passageway to the occluder is then provided but only when the receptacle is squeezed to deform the latter, thereby forcing the liquid through the tube 21 into aperture 22 and against the ball 24 to raise it away from the O-ring 25. The liquid moves from the chamber 23 and then into the liquid passageway 30 of the occluder 13 and is finally dispensed from the end of the passageway 30 into the nostril in which the portion 44 has been inserted. The dispensing occurs as soon as squeezing of the receptacle takes place and will continue so long as squeezing is possible.
When the pressure due to squeezing is removed from the pliant receptacle 11 it can return to its normal position only when the air forced out of the receptacle by squeezing can be replaced by air from the outside of the receptacle so that an air pressure differential no longer exists between the inside and outside of the receptacle 11. This pressure release takes place immediately thereby causing spring 26 to return ball 24 into engagement with O-ring to prevent any further dispensing of the liquid. Further, as the pressure release takes place, the pressure differential between that inside and that outside the receptacle 11 is equalized. This is due to the outside pressure via the air entry opening 36 and aperture 35 causing ball 37 to disengage from O-ring 38, thereby permitting air to enter receptacle 11 to establish an equalization of pressure. Once the pressure has been equalized, the ball 37 assumes its normal position closing the aperture 35 in view of the force exerted thereagainst by the spring 39. Hence, with the balls 29 and 37 in their sealing positions there is no possibility of any dispensed liquid reentering the receptacle 11 to contaminate the liquid not yet dispensed.
Reference is now made to FIG. 4 in which another embodiment of the invention is disclosed and described. In this arrangement the intermediate member 50 is provided with two (2) passageways, the first being the liquid passageway 51 and the second being the air passageway 52 which is used to equalize the air pressure between the atmosphere and the inside of the receptacle 11. The structure for securing the intermediate member 50 to the open end 14 of the receptacle 11 is the same as that described hereinabove. However, in place of spring biased balls for controlling the opening or closing of the passageways a commercially available check valve is utilized. The check valve 53 as shown in FIG. 4, is arranged within the extension 29 of the occluder 13 rather than in the intermediate member 12 and the check valve 54 for controlling the entrance or equalization of the air pressure between the inside and outside of the receptacle 11 is inserted and sealed in the counterbore 55 in the end of the air passageway 52. Alternatively, the check valve 54 can be contained by a plate, as shown in FIG. 2 having only a hole in alinement with the liquid passageway 51 for receiving the extension 29 of the occluder 13.
The check valve 53 is shown in FIG. 4 as being arranged in a counterbore 56 in the extension 29 of the occluder 13 and coextensive with the liquid passageway 51 and the counterbore 20. The check valve 53 seals the liquid within the receptacle 11 and prevents any flow of the liquid until the pliant receptacle 11 has again be squeezed to dispense the liquid.
In FIGS. 6 and 7 the check valves as designated by 53 and 54 hereinabove, is shown in the positions assumed when arranged in the intermediate member 50, as shown in FIG. 4. The valve is made of a very soft polyethylene material and is commercially available for use in small apertures or openings. In FIG. 6 the normally closed position is shown with the lips 57 in contact with one another to maintain a closed position so long as there is no pressure differential relative to either side of the valve. In FIG. 7, however, when the pressure is no longer equalized, the lips 57 will open, thereby permitting a flow of liquid or air. When the entry of air has equalized the pressure in the present disclosure, the lips 57 will close and the receptacle will assume its normal position or form and be ready for another deformation to inject another flow of liquid via the liquid passageways into the nostril via the occluder 13. It can be readily appreciated that the check valve provides a means for controlling the flow of liquid upon deformation of the pliant receptacle and the direction of flow is only in a direction to discharge the flow from the occluder into the nostril. As described more fully hereinabove, once the pressure has been released from the receptacle, the difference in pressure between the inside and outside of the receptacle causes the check valve 53 in the liquid passageway 51 to close and the check valve 54 in the air passageway 52 to open and remain open until the pressure has been equalized. Through this arrangement any liquid discharged from the occluder into the nostril cannot re-enter the receptacle because of the check valve arrangement. Therefore, any contamination that may have been added to the liquid after it has been dispensed cannot re-enter the receptacle through the occluder 13. Also, with the structure herein provided the structure can be completely disassembled and reassembled for cleaning and disinfecting or sterilizing. Further, at no time is there a possibility of leakage of the liquid from within the receptacle, irrespective of the position of the receptacle.
As set forth hereinabove it can be readily appreciated by anyone skilled in the art that the invention disclosed herein provides a novel way of achieving a result not heretofore possible with presently used dispensers. There may be differences that can be affected without altering the operation, function or purpose of the invention as described and disclosed hereinabove. For example, it has been found that a plastic material is very satisfactory for use as the intermediate member and the occluder inasmuch as such material is easily shaped or molded, light in weight and readily cleaned and sterilized.
Accordingly, the invention has been disclosed in detail with particular reference to preferred embodiments thereof but it will be understood that variations and modifications can be affected within the spirit of the invention.
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The invention relates to a device for unidirectionally dispensing a hygienic cleaning and/or flushing liquid into the nasal and sinus cavities when an occluder is inserted into one of the nostrils. The liquid is contained in a pliable container which, upon insertion of the occluder into one of the nostrils and deformation of the container per se by squeezing, will cause the liquid to move via a passageway to the occluder and into the nostril. The device is provided with an anti-retractive valve which permits a unidirectional flow of the liquid only in a dispensing direction so any contaminated liquid that had been previously dispensed cannot reenter the container through the liquid dispensing passageway.
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CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims benefit of U.S. Provisional Patent Applications No. 61/132,258, filed Jun. 16, 2008, and No. 61/212,694, filed Apr. 15, 2009, the disclosures of which are incorporated herein by reference in their entirety.
BACKGROUND OF THE INVENTION
[0002] In the ongoing endeavor to use multiple light emitting diodes (LEDs) in commercial lighting fixtures, there are two primary aspects, optical and thermal, that require careful consideration. Several US patents disclose reflective types of LED combiners. In U.S. Pat. Nos. 7,246,919 B2; 6,846,100 B2; 6,598,996 B1; and 6,364,506 an array of LEDs is mounted on a planar base, attached to an Edison screw connector. That approach, however, enlarges the emitting area and complicates thermal management. U.S. Pat. Nos. 7,249,877 and 6,682,211 B2 put an LED array at a location corresponding to the filament location of a corresponding incandescent bulb, but cooling is adequate only for low-power LEDs. What is needed is a fresh approach to multiple-LED employment, offering both superior cooling and compact beam-forming optics.
SUMMARY OF THE INVENTION
[0003] One aspect of the present invention is a complete light source, comprising multiple LEDs, their optics, drive electronics, and integral cooling via a cylindrical housing. The LEDs are either mounted on the interior surface of the cylinder, facing radially inwards or optionally are mounted on the exterior of the cylinder, facing radially outwards. The cylinder is preferably metallic, or a composite material with adequate thermal conductivity, with external or internal fins for convective cooling. Alternatively, the cooling can be accomplished using the novel approach described in U.S. Provisional Application 61/205,390 titled “Heat Sink with Helical Fins and Electrostatic Augmentation” by several of the same inventors. This application is incorporated herein by reference in its entirety.
[0004] Each LED, or group of LEDs, has its own reflector, which forms an output beam running along the cylinder axis. A plurality of such LEDs, preferably four or more, and their reflectors are nested outside and/or inside the cylinder, with the light coming out one end of the reflector. The electrical power cabling and mechanical supports may come out the other end of the reflector. The combined light output of the four or more reflectors forms a typical PAR-type flood pattern. The advantage of this approach is multi-fold. The optical efficiency of the system is very high as the only losses come from absorption losses of light striking the reflectors. As such the intercept efficiency is typically at 90% (amount of light from the LED that gets to the target, with optical efficiency=reflectivity*intercept efficiency). In addition, the design may be made extremely compact allowing the system to operate inside a conventional 6 inch (15 cm) diameter ceiling can of conventional downlights.
[0005] Furthermore, the architecture aids in the creation of thermal cooling via convection loops even inside an insulated can. Using state-of-the-art white LEDs, the system can safely handle 15 watts of electrical power input to the LEDs (of which about ¾ is converted into heat) even with the system installed in an insulated can, as long as the room temperature is 35° C. or less. For example, using five CREE Corporation (of North Carolina) model MC-E white LEDs, flux levels of well over 1400 lumens (cool white) can be projected onto the floor. Using warmer color LEDs from the same manufacturer and others, the system can output approximately one thousand lumens with a color temperature under the 3000° K of incandescent light bulbs. This can be achieved with a sizable temperature safety margin for the system components. Thus this new approach makes it possible to produce solid state replacement lamps for the most popular PAR 20 and PAR 30 lamps, and even some PAR 38 lamps.
[0006] Other aspects of the invention provide reflector and cylinder sub-assemblies around which the complete light source may be built.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] The above and other aspects, features and advantages of the present invention will be apparent from the following more particular description thereof, presented in conjunction with the following drawings wherein:
[0008] FIG. 1 is a bottom plan view of a light source with four LEDs mounted internally on a cylindrical heat sink.
[0009] FIG. 2 is a perspective view of the light source shown in FIG. 1 .
[0010] FIG. 3 is a perspective view of the light source shown in FIG. 1 , showing light output, both reflected and unreflected, from one LED.
[0011] FIG. 4 is a perspective view of the light source shown in FIG. 1 , showing unreflected light output from one LED.
[0012] FIG. 5 is a perspective view of the light source shown in FIG. 1 , showing the entire output of the light source.
[0013] FIG. 6 shows the illuminance pattern of the light source of FIG. 1 .
[0014] FIG. 7 shows the far-field intensity pattern of the light source of FIG. 1 .
[0015] FIG. 8 shows a perspective view of a 5-LED light source.
[0016] FIG. 9 is a contour graph of illuminance when one LED of the 5-LED light source of FIG. 8 is emitting.
[0017] FIG. 10 is a contour graph of illuminance when all LEDs of the 5-LED light source of FIG. 8 are emitting.
[0018] FIG. 11 shows an isometric view of the illuminance when all LEDs of the 5-LED light source of FIG. 8 are emitting.
[0019] FIG. 12 shows a perspective view of a light source with 10 LEDs and reflectors, mounted externally on a cylindrical heat sink.
[0020] FIG. 13 shows a perspective view of a light source with five LEDs, along with primary and secondary reflectors.
[0021] FIG. 14 is a close-up perspective view of one of the LEDs and its reflectors, showing light rays.
[0022] FIG. 15 is an isometric view of the illuminance distribution produced by the light source of FIG. 12 .
[0023] FIG. 16 is an illuminance contour graph for the 10-LED system of FIG. 12 with one LED emitting.
[0024] FIG. 17 is an illuminance contour graph for the system of FIG. 12 with all 10 LEDs emitting.
[0025] FIG. 18 shows an isometric view of the illuminance when all LEDs of the 10-LED light source of FIG. 12 are emitting.
[0026] FIG. 19 shows an isometric view from the same 10-LED light source when the LEDs are moved away from their nominal position.
[0027] FIG. 20 shows a modified form of the design of FIG. 12 with both smooth and faceted sections for simplified molding.
[0028] FIG. 21 shows a peened 5-LED reflector system with the reflectors facing inwards.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0029] A better understanding of the features and advantages of the present invention will be obtained by reference to the following detailed description of the invention and accompanying drawings, which set forth illustrative embodiments in which various principles of the invention are utilized.
[0030] Referring to the drawings, and initially to FIGS. 1 through 5 , FIG. 1 shows a plan view of an embodiment of a light source, indicated generally by the reference number 100 , comprising LED packages 101 , ellipsoidal reflectors 102 , mounting cylinder 103 , and convective fins 104 . The ellipsoidal reflectors 102 are mounted on the inside of the cylinder 103 , with each LED package 101 mounted centrally within a respective reflector 102 . The fins 104 extend axially along, and project radially from, the outside of the cylinder 103 . When the light source 100 is mounted in a ceiling can, the view shown in FIG. 1 is the view of the light source 100 as seen looking up from the floor.
[0031] The downward intensity of the direct light from the LEDs is very low, one of the advantages of this design. Also, the area of the images of the LED sources seen from below is very small. Each LED appears to the observer as two small point like sources. One apparent source is the actual LED, which is the source of the portion of the light that exits the device without reflection. The other apparent source is the virtual source of the portion of the light that is reflected from beam forming optics before exiting. (In a more general case, the virtual source could appear as more than one apparent point-like source.) Thus, the bulb (light source 100 as a whole) in a direct view appears as a compact “stars” field. This is advantageous as it reduces the glare compared with light sources that are extended in area, which is the case for most current solid state light products. The reason for this advantage is that the human eye has adapted over thousands of years to be comfortable seeing many small bright objects on a dark background (the stars) but has not adapted as well for large area sources (a more recent phenomenon). An illuminating apparatus intended to simulate the appearance of a starry sky is described in U.S. Pat. No. 5,219,445 to Bartenbach.
[0032] FIG. 2 shows a perspective view of the light source 100 of FIG. 1 , also showing a better view of a mounting wedge 101 w . The mounting wedges 101 w are interposed between LED packages 101 and cylinder 103 so that package 101 faces slightly downwards, at a 10° angle from the wall of cylinder 103 . Wedge 101 w is preferably composed of a highly thermally conductive material such as copper.
[0033] FIG. 3 shows a different perspective view of the same light source 100 , also showing rays 105 r that, after being emitted by one of the LEDs 101 , are reflected by the ellipsoidal mirror 102 into a caustic at the second focus of ellipsoid 102 . As may be seen from the pattern of rays 105 r in FIG. 3 , the LED 101 is approximately at the first focus of the ellipsoid 102 , and the second focus is approximately vertically below the first focus, and below the bottom rim of reflector 102 and mounting cylinder 103 . FIG. 3 also shows direct rays 105 d , which are rays emitted straight out from the same one LED 101 without meeting mirror 102 .
[0034] FIG. 4 shows a different perspective view of the same light source 100 , showing only direct rays 105 d.
[0035] FIG. 5 shows a further perspective view of the same light source 100 , showing light emission 105 of all four LEDs 101 . (The LEDs themselves are not visible in FIG. 5 because of the angle of view).
[0036] FIG. 6 shows an isometric view of a normalized illuminance graph 200 , having a horizontal X axis 201 and horizontal Y axis 202 , with scales in millimeters, and vertical intensity axis 203 , running from 0 to 1. Graphical surface 204 represents the spatial distribution of light 3 meters from the light source. The Z axis in FIG. 6 is assumed to be the axis of symmetry of light source 100 (vertically downwards for a ceiling can light) and the mounting cylinder 103 with its cooling fins 104 is assumed to fit within a 6″ (15 cm) diameter ceiling can.
[0037] FIG. 7 shows a normalized intensity graph 300 , comprising horizontal axis 301 representing emission angle in degrees of arc from the axis of cylinder 103 of FIG. 1 and vertical axis 302 representing azimuthally integrated relative output in percent. Curved line 303 shows the angular intensity of light source 100 of FIG. 1 , relative to 100% on axis, falling to zero at about 60° off axis. Dotted curve 304 is a cumulative energy curve that shows as a function of angle off axis the energy of the part of the intensity distribution of light source 100 within a cone having the specified half-angle centered on the axis. Although the half-power point is at 20° off-axis, half the total energy is within 18° off-axis, a characteristic of a ‘peaky’ distribution, which is typical of commercial incandescent PAR lamps.
[0038] In case a light source with five LEDs is desired, FIG. 8 shows a perspective view of a further embodiment of light source 400 , comprising five LED packages 401 , toroidal reflectors 402 , mounting cylinder 403 , and convective fins 404 (not shown to scale). Coordinate triad 405 has its Z axis along the center axis of mounting cylinder 403 , and is aligned with the particular reflector 406 which is numbered, that is to say, with the negative direction of the Y axis radially outward through the center of the particular reflector 406 . The toroidal reflector differs subtly from an ellipsoidal shape. In a local coordinates system with the origin at the reflector apex, the toroid is described by the equation:
[0000] Sag=( v x x 2 +v y y 2 )/(1+sqrt{1−(1+ k x ) v x 2 x 2 −(1+ k y ) v y 2 y 2 }),
[0000] where v x , v y are sagittal and meridional curvatures and k x , k y are conic coefficients. Each reflector is oriented with the y axis of the sag coordinate system radial to the mounting cylinder 403 , in the 0YZ plane of triad 405 . The sag describes the axial position z of the point with coordinates (x,y). The following table provide k x , k y , v x , and v y coefficients for two preferred embodiments for the 5-LED light source of FIG. 8 . Embodiment #1 uses a CREE MC-E LED and Embodiment #2 uses a Nichia NCSL 136 LED.
[0000]
Parameters
k x
k y
v x
v y
A
Embodiment #1
−0.56
−0.49
1/9.10
1/9.42
16°
Embodiment #2
−0.57
−0.49
1/7.65
1/7.85
15.8°
[0039] Starting from the coordinate system 405 shown in FIG. 8 , the sag-axis coordinates of the reflector as described above are shifted in the −Y direction of coordinate system 405 by 28.3 mm for embodiment #1 and by 28.5 mm for embodiment #2 and then rotated through the angle A counter-clockwise relative to the positive X direction (that is to say, angling the sag-axis of the toroid towards the center of the illuminated area beyond the exit end of the light source 400 ), around the point with coordinates shown in the table of rotation points below.
[0040] For the two embodiments the coordinates of the points of rotation on angle A are
[0000] Y/mm Z/mm Embodiment #1 −28.3 7.2 Embodiment #2 −28.5 6
in the coordinate system 405 with its origin at the center of cylinder 403 .
[0041] The source center positions are
[0000]
Y/mm
Z/mm
Embodiment #1
−28.4
7.434
Embodiment #2
−29.7
6.195
[0042] The foci of the toroid are the following positions
[0000] Meridional Sagittal Y/mm Z/mm Y/mm Z/mm Embodiment #1 −28.542 6.356 −28.67 5.88 Embodiment #2 −28.701 5.287 −28.807 4.912
The tolerances for foci positions with respect to the source positions are 0.1 mm in x,y,z directions.
[0043] The inside diameter of the cylinder 403 is designed for the mounting of LEDs and equal to 56.8 mm for Embodiment #1 and 59.4 mm for Embodiment #2. Thus, the LED sources are approximately flush with the inner face of the mounting cylinder 403 . Attaching the LED sources to the face of the mounting cylinder 403 is in practice sufficiently close to flush. The minimum length of the cylinder 403 and reflectors 402 for Embodiment #1 is 27 mm and for Embodiment #2 is 22 mm. The length can be extended away from the exit end to provide space and support for LED drivers and other electronics. Both Embodiment #1 and Embodiment #2 produce a ±30° output beam.
[0044] The toroidal reflectors 402 are double ellipsoids having an aspheric modification that induces tailored aberrations. The aberrations' function is to remove source irregularities from the beam pattern output. That assists in producing a uniform circular output (as the combined output from all the light sources) for the central part of the pattern.
[0045] For the lux values projected by a single LED of FIG. 8 , FIG. 9 shows contour graph 500 with lux values listed and lined up with their corresponding contours. This is based on the output of Embodiment #1. FIG. 10 shows contour graph 550 for all LEDs of FIG. 8 , also with lux values listed, of course much higher than in FIG. 9 . FIG. 11 is an isometric view of illuminance at the plane 3 meters from the bulb, in which graph 600 has a surface 601 representing the lux values at each X, Y point under the lamp. The X and Y coordinates are in meters. The pattern for the case when all five LEDs are turned on is circular to a good approximation. The output pattern from a single LED is asymmetric. This is a novel approach as the prior art requires that each of the five beam outputs have circular symmetry. One benefit of this new approach is that the dimensions of the lamp can be reduced (versus the prior art), especially the diameter. This allows the lamp to be small enough to fit into a standard can while still achieving high flux.
[0046] For most purposes, the output pattern when all LEDs are turned on is sufficiently close to circular that any trace of polygonal pattern can be ignored. However, in special situations the number and orientation of the LEDs (four as shown in FIG. 1 , five as shown in FIG. 8 , or another number) may be chosen to provide a desired illumination pattern and/or a desired appearance when the light source 100 , 400 , etc. is viewed directly. In such cases, it may be appropriate to configure the light source with a more pronounced polygonal light distribution that would usually be regarded as non-optimal.
[0047] FIG. 12 shows a perspective view of a further embodiment of a light source 700 , comprising ten LED packages 701 , their ten reflectors 702 , mounting cylinder 703 , and convective fins 704 . Interior convective fins 704 are diagrammatic rather than representative of actual designs. Typically, the surface area of the fins will be 10 square inches (65 cm 2 ) or more for each watt of heat from the LEDs. Also, in order for the convective loop to function properly in an insulated can, the distance between the fins should be approximately 10 mm. As described, the light source 700 shown in FIG. 12 has a mounting cylinder 703 approximately 33 mm in radius, implying a circumference of 20 cm, so about 20 fins instead of the 80 fins shown. If the total heat dissipation is about 10 Watts thermal, which is a reasonable target for an LED downlight, each fin might then be around 1 cm (0.4 inches) in radial width and 16 cm (6.5 inches) in axial length, which is feasible within the dimensions of a conventional ceiling can. However, smaller fins may be preferred, for aesthetic reasons, where a lower thermal load permits. A more efficient cooling system uses the helical vanes of U.S. Provisional Application 61/205,390, or better still, the helical vanes with electro-static augmentation described in that application, which is incorporated herein by reference. Using the helical fins of that application, the length of the thermal management device can be reduced to 5 cm (2 inches), or only about one third of the length of the vertical system mentioned above, without reduction in cooling capacity.
[0048] With ten of the current Cree XP-E LED's this embodiment can provide 800 to 1000 lm light output (warm white). The following table provides k x , k y , v x , and v y coefficients for a preferred embodiment for the 10-LED light source of FIG. 12 .
[0000]
Parameters
k x
k y
v x
v y
A
−0.57
−0.54
1/7.55
1/6.9
16°
[0049] Starting from the central axis of mounting cylinder 703 shown in FIG. 12 , the sag-axis coordinates of the reflector as described above are shifted radially outward by 35.5 mm and then rotated through the angle A counter-clockwise relative to the positive X direction. The angle of rotation for reflector 706 in FIG. 12 is in the direction of arrow 707 for coordinate system 705 for FIG. 12 .
[0050] The coordinates for the center of rotation for angle A are:
[0000] Y/mm Z/mm 35.5 6
in the coordinate system 705 with its origin at the center of cylinder 703 .
[0051] The source center position is
[0000] Source center position Y/mm Z/mm 33.8 5.425
and the axis of the LED is orthogonal to the axis of the cylinder 703 .
[0052] The positions of the foci of the reflector nearest the source are:
[0000]
Meridional
Sagittal
Y/mm
Z/mm
Y/mm
Z/mm
35.08
4.54
35.103
4.846
[0053] FIG. 16 shows contour graph 1000 of the illuminance values in lux projected by a single XPE LED for the embodiment of FIG. 12 . FIG. 17 shows illuminance contour graph 1050 with all ten XPE LEDs of FIG. 12 emitting. FIG. 18 is an isometric view of illuminance for the ten-LED lamp on a plane 3 meters from the lamp. The X,Y coordinates at the illuminated plane are shown in mm. The pattern for the case when all ten LEDs are emitting is circular to a good approximation. The output pattern from the single LED is asymmetric. This is a novel approach as the prior art requires that each of the ten beam outputs have circular symmetry. In FIG. 16 the maximum intensity from the single LED spot is shifted away from the central axis of the lamp. Superposition of all ten LEDs creates the circular spot with the extended flat plateau shown in FIGS. 17 and 18 .
[0054] FIG. 19 shows an illuminance contour graph 1200 for a spot located at 3 meters from the lamp of FIG. 12 with 10 XPE LEDs all illuminated, with the LEDs shifted out of the nominal position 0.3 mm in the axial lamp direction (Z direction in FIG. 12 ) and 0.3 mm in lateral −X,Y direction. Contours are at steps of 14 lux from 0 lux to 112 lux. The size of the spot is the same as in FIG. 17 . The central part of the pattern with a flat plateau is transformed to a Gaussian type distribution. This elevates the illumination level at the center of the spot to 112 lux. Such performance tolerances are acceptable for typical illumination applications. Therefore, the lamp can be said to have a ±0.3 mm tolerance for positioning of the LEDs, an acceptable dimensional tolerance for volume manufacturing.
[0055] FIG. 13 shows a further embodiment of a luminaire 800 , comprising five lamps, with LEDs 801 , each located off the focus of a respective cutaway paraboloidal primary reflector 802 . The LEDs and reflectors are mounted on chimney 803 , having interior fins 803 f . The paraboloidal primary reflectors 802 face upwards and outwards. Struts 804 are connected to chimney 803 to support toroidal secondary reflectors 805 , above the primary reflectors 802 , which serve to spread out the light onto the floor below. The radial curvature of reflector 805 sends some of the light back under the associated primary reflector 801 so it can reach the part of the floor directly below the luminaire. The azimuthal curvature spreads the light out so the five patterns suitably overlap. FIG. 13 is a close-up perspective view of one of the LEDs 801 and its associated reflectors 802 and 803 of luminaire 800 , showing light rays 801 R.
[0056] FIG. 15 shows an isometric view of an illuminance graph 900 with surface 901 representing strength of illumination over the x and y axes on the floor under light source 800 of FIG. 13 . A smooth, nearly circular pattern results from the superposition of the five patterns of the individual secondary reflectors. The two curvatures of toroidal secondary reflector 805 of FIG. 12 can be adjusted for different illumination patterns. In fact, the reflector 805 could have two surfaces of different shapes back to back, for example, two toroidal surfaces that differ in one or both of their primary curvatures, for different patterns. The two-surface reflector 805 would then be mounted so it can be rotated (not shown) around strut 804 so either of two toroidal surfaces could be selected.
[0057] Although the embodiments described herein use reflectors that are smooth and specular, the invention also includes embodiments where the reflectors make use of spreading surface features such as faceting, peening or mild diffusers (including kineform or holographic structures). Using spreading features on the reflectors homogenizes the beam more than specular reflectors but has the effect of spreading the beam output angle and tends to eliminate the sharp cut-off at the periphery of the beam. This may be desirable in some lighting applications. The effect of spreading features (faceting, peening, etc.) on beam output is described in the book “The Optical Design of Reflectors” by William B. Elmer, on pages 27 thru 29, which is incorporated herein by reference. In particular, equations 1, 2 and 3 in Elmer provide a way of quantitatively predicting the effect of spreading features based on the average diameter of the peened spots, their radius and the radius of curvature of the reflector. Elmer also provides a simplified equation for the special case of flat facets. Of course the range of possible spreading surfaces is not limited to those described by Elmer. It should be evident to those skilled in the art how such spreading features can be applied to the designs of the present application to achieve a required or desired beam output.
[0058] In some cases it is desirable to have a hybrid reflector where a portion of the reflector is specular and another portion uses spreading features. That can be useful for eliminating artifacts in a beam pattern where the artifacts stem from a particular segment of the reflector. In that situation the reflector can be shaped so that only the segment causing the problem has spreading features on it.
[0059] For the embodiments described herein for the 5-LED and 10-LED systems, the reflectors are designed to wrap around the source and are considered re-entrant surfaces from the standpoint of molding technology. The molding of these parts is still possible for those skilled in the art of designing and manufacturing molds. Indeed it is possible even to mold multiple reflectors (10 in the case of FIG. 12 ) at once. Alternatively, the array of reflectors (five or ten respectively for the embodiments of FIG. 8 and FIG. 12 ) can be molded in two halves with a draft angle at or near zero degrees for each half. Finally, it is also possible to simply remove the small portion of the reflector that is re-entrant. Removal of this small section of the reflectors has little effect on the illumination pattern from the light source, as was proven by extensive ray tracing modeling carried out by the inventors.
[0060] FIG. 20 shows one half of a mold 1300 for a hybrid version of the embodiment of FIG. 12 combining triangular planar facets 1301 and smooth surfaces 1302 to make the 10-reflector part more easily moldable. No part of the 10-reflector array of FIG. 20 is re-entrant, and therefore a single 10-reflector part comprising the mounting cylinder 703 , cooling fins 704 , and reflectors 706 can be molded in one piece using simplified molding techniques. The performance of the hybrid-reflector system is equal to the preferred embodiment previously described herein.
[0061] FIG. 21 shows a peened embodiment 1400 with 5 reflectors, wherein the reflectors are facing inwards, as in FIG. 8 . The mounting cylinder is omitted from FIG. 21 to allow a clearer view of the reflectors. The peening features are sections of a sphere such that each feature produces a very similar circular pattern in the far field, thereby creating the desired beam pattern by multiple overlapping of beams with the same angle and shape (as opposed to the other approach described in this application). The overall shape of the reflectors in FIG. 21 is parabolic or it can also be compound parabolic. The peening features then convert the collimated beam from the original parabolic reflector into a uniform circular beam pattern with a desired divergence, controlled by the curvature of the individual peening features, that is wider than the pattern of the parent collimated beam. This is an alternative embodiment of the invention. This approach can also be used with other embodiments, including embodiments in which the reflectors facing outward as opposed to inward.
[0062] The preceding description of the presently contemplated best mode of practicing the invention is not to be taken in a limiting sense, but is made merely for the purpose of describing the general principles of the invention. The full scope of the invention should be determined with reference to the Claims.
[0063] Although various embodiments have been described, the skilled reader will understand how features of the different embodiments may be combined.
[0064] Various changes may be made in the described light sources without departing from the scope and spirit of the invention as claimed. For example, although the actual emitters of light are described as light emitting diodes (LEDs), other emitters, including emitters hereafter to be developed, may be used instead. Further, each LED package 101 , 401 , 701 , 801 or other light emitter may comprise a plurality of LEDs mounted close together within a common modified or unmodified ellipsoidal reflector. The LEDs within each package may then be the same or different, and may be switched on or off together or separately.
[0065] The light sources shown in the drawings have been described as being used in ceiling can lights, but for convenience of illustration have in many cases been drawn with the exit end (which would be downwards in a ceiling fixture) facing upwards in the drawing. Terms of orientation such as “bottom” are used with reference either to the normal orientation of the light sources in ceiling fixture use or to the orientation shown in the drawings. However, these and other light sources according to the invention may of course be used, mounted, and stored in either of those orientations or in other orientations.
[0066] The light sources shown in the drawings have been described as being circular, with the LED packages and reflectors evenly spaced around the axis of the mounting cylinder. However, for some purposes, for example, a wall-sconce designed to match the embodiments shown, the LED packages and reflectors may form an incomplete ring. For example, a wall-sconce designed to match the embodiment shown in FIGS. 13 and 14 might have the cylinder 803 mounted close to the wall, and only three of the five sets of components 801 , 802 , 803 , 805 . A wall-sconce designed to match the embodiment shown in FIGS. 1 to 5 , or FIG. 8 , or FIG. 12 might have an incomplete mounting cylinder mounted with its open side against the wall, or in the case of a semicircular mounting cylinder with its open side against a mirror, so that the real and mirror-image halves form a complete, circular luminaire.
[0067] The mounting cylinder 103 , 403 , 703 , 803 has been shown in the drawings as a right circular cylinder. The circular cylinder is simple to design, simple to manufacture, robust, and aesthetically pleasing. Other shapes, including a polygon or a shape intermediate between a polygon and a circle, are of course possible. To avoid redesigning the optics, a shape that maintains the even positioning of the LED packages and optics on a notional circle is preferred. In a practical embodiment, the cylinder may have a slight conical draft for ease of molding.
|
A cylindrical light source comprises multiple LEDs mounted on either the exterior or interior surface of the cylinder, with heat-sink fins respectively on its interior or exterior. The LEDs emit radially, but their emission is redirected along the cylinder axis by individual ellipsoidal reflectors.
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BACKGROUND OF THE INVENTION
1. Technical Field
This invention relates generally to cutting systems and more particular to a device for separating a multiple partitioned printed circuit board.
2. Description of the Prior Art
Printed circuit boards are being utilized more in electronic systems as the cost of assembly becomes an increasingly greater part of such systems. To reduce overall manufacturing costs, certain steps have been adopted for assembly of the boards. For example, through-hole components and surface mounted components are conveniently installed in predetermined positions on a printed circuit board by automated equipment such as "pick and place" machines or by a highly skilled operator. To further reduce costs through increased efficiency, in some operations, the through-hole and surface mounted components are assembled on a large substrate that has been previously partitioned into a multiple printed circuit board containing two or more individual circuit boards. This multiple or partitioned printed circuit board is then fully populated with through-hole and surface mounted components at one or more work stations by the automated equipment or operator.
An additional step in the assembly of electronic systems involves the process of separating the partitioned printed circuit board into the individual circuit boards. A number of methods and devices are known and available for performing this operation.
One such method involves a "punch and reinsert" operation wherein the individual circuit boards are punched out of the large substrate before components are inserted thereupon. These circuit boards are then reinserted back into the substrate where they are held by friction while the components are inserted thereupon. Once all the components are inserted, the individual circuit boards are again separated from the substrate. The separation operation involves having an operator warp or distort the substrate such that the individual circuit boards are dislodged. Some stresses are, unfortunately, imparted to the boards through this process and could possibly, damage the boards or the components thereon.
Other methods involve cutting a partitioned printed circuit board once it has been populated with through-hole and surface mounted components. One of these methods involves the use of a band saw which separates the individual circuit boards and also cuts away the excess stock around the border of these boards. This method imparts vibrations to the printed circuit board, however. These vibrations propagate across the board and, in turn, may cause damage to the solder junctions electrically connecting the through-hole and surface mounted components to the board. Also certain surface mounted components are very susceptible to the vibrations from the band saw and may be easily damaged thereby. This method is normally not preferred therefore because of the large vibrations imparted to the printed circuit board through its use.
Another method involves using a water knife cutter which, like the band saw, separates the individual circuit boards and also cuts away the excess stock around the border of these boards. Unlike the band saw, however, the water knife exerts minimal contact pressure on the material being cut due to the small surface area of the water jet stream. Thus, the water knife cutter provides an acceptable method of separating the boards since it exerts minimal stress and vibrations on the boards and therefore the components connected thereon. The disadvantage of this method is the relatively high cost of acquiring a machine employing this type of cutting system.
In keeping with the overall effort to reduce the cost of manufacturing electronic systems, what is desirable, therefore, is an economical device and method that will separate a multiple partitioned printed circuit board into individual circuit board sections without damaging the solder junctions and surface mounted components affixed thereupon.
SUMMARY OF THE INVENTION
In accordance with the invention, a device separates a multiple partitioned printed circuit board without damaging solder connections and delicate surface mounted components attached to the board. The device comprises at least one pair of disc cutters positioned in opposed alignment and minimally spaced apart for providing a bifurcated cutting edge which, upon engagement, conveys and separates the board. The device also comprises a transporter for supporting the board while it is conveyed through the bifurcated cutting edge. The multiple partitioned printed circuit board is thus separated into individual circuit boards with minimal longitudinal and vertical forces being exerted thereupon thereby avoiding damage to the solder connections and surface mounted components.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a perspective view of a first embodiment of the board separator assembly in accordance with the invention;
FIG. 2 is a top view of the device shown in FIG. 1;
FIG. 3 is a partial sectional view of the device shown FIG. 2 along the lines A--A;
FIG. 4 is a partial sectional view of the device shown in FIG. 2 along the lines B--B;
FIG. 5 is a top view of a second embodiment of the board separator assembly in accordance with the invention; and
FIG. 6 is a partial sectional view of the device shown in FIG. 5 along the lines C--C.
DETAILED DESCRIPTION
Throughout the drawings, the same elements when shown in more than one figure are designated by the same reference numerals.
With reference to FIGS. 1 through 4 in combination, a board separator assembly 10 shown in perspective view in FIG. 1 includes a base slab 11 and two upstanding side plates 12 and 13 mounted thereupon. Affixed to side plates 12 and 13 are a driver shaft 14 and an idler or driven shaft 15, both more easily seen in FIG. 4. Driver shaft 14 includes mounted disc cutters 16 and 17. Similarly, driven shaft 15 includes mounted driven disc cutters 18 and 19. Disk cutters 16 and 17 are respectively mounted in opposed relationship with disc cutters 18 and 19 to form a first and a second bifurcated cutting edge. Also mounted on the upstanding side plates 12 and 13 is a transporter 20 for supporting a partitioned printed circuit board as the board moves through the cutting edges formed respectively in combination by disc cutters 16 and 18 and 17 and 19.
The transporter 20 includes indexing pins 21 through 24 for mating with openings provided generally at the end or sides of a partitioned circuit board for correct positioning of the board in the board separator assembly. A recessed area 25 on the transporter 20 allows for the partitioned printed circuit board to be properly positioned on the transporter without the surface mounted components located on the bottom thereof contacting the transporter 20.
The transporter 20 also includes parallel and opposed slots 26 and 27. These slots respectively provide clearance for the outer rim of the disc cutters 16 and 17 to project through as the transporter is moved over these disc cutters.
Directional guidance for the transporter is provided primarily by a rod 28 which is attached to one side of the transporter 20 throughout its length. This rod 28 secures the transporter and transverses through two linear Ball bearings 29 and 30 embedded in the upstanding side plate 12. Movement of the transporter 20 is also limited in a direction perpendicular to the direction of translation by upper roller guide pins 31 and 32 and lower roller guide pins 33 and 34 mounted in the upstanding side plate 13.
Both the driver shaft 14 and driven shaft 15 are held in alignment in the side plates 12 and 13 by a roller bearing positioned on each side and illustratively shown in FIGS. 1 and 4 by roller bearings 36 and 37 respectively. Limiting collars 41 through 43 secure both ends of the driven shaft 15 and a first end of the driver shaft 14 to the side plates 12 and 13. Securing a second end of the driver shaft 14 is a drive 35 attached for rotating the driver shaft and therefore the driver disc cutters 16 and 17. This drive means may be, for example, either a stepper motor or even a hand crank for manual rotation of the the driver disc cutters 16 and 17.
A tongue and groove assembly in both of the side plates 12 and 13 houses the two roller bearings, e.g. bearing 36, supporting the driver shaft 15. This assembly allows for adjustment of the height of the driven shaft 15, thereby setting the spacing between the upper and lower disc cutters. End caps 38 and 39 respectively retain the tongue and groove assemblies in side plates 12 and 13. Adjusting screws 43 and 44 respectively cooperate with compression springs 45 and 46 in adjusting the height of the driven shaft 15 such that the spacing between the driver disc cutters 16 and 17 and the driven disc cutters 18 and 19 is only a few thousandths (typically 3-5 thousandths) of an inch apart.
By way of operations, a populated partitioned circuit board ready to be separated is positioned on indexing pins 21 through 24 by an operator or suitably automated machinery. The transporter 20 is then advanced to a point where the two disc cutter pairs 16 and 18 and 17 and 19 engage the circuit board. This initial advancement of the transporter 20 may be either by mechanical means or simply by manual means where an operator advances the transporter 20 to the engagement point by utilizing an opening 48. Once the board is engaged by the disc cutter pairs, the drive 35 begins to rotate the driver shaft 14 and the board is cut as it advances between the driver disc cutters 16 and 17 and the driven disc cutters 18 and 19. Beyond the engagement point the drive 35 is the only means used to advance the circuit board and transporter 20. The partitioned circuit board is thus separated with minimal longitudinal force, the vertical force being confined to an area between the cutting edges. Thus minimal stress is applied to the solder connections and the surface mounted components as the board passes between the driven and driver disc cutters.
With reference to FIGS. 5 and 6 in combination, a second embodiment of a board separator assembly 50 is disclosed in accordance with the present invention. The structure and operation of this board separator assembly is similar to that of the board separator assembly 10 shown in FIGS. 1 through 4. The principal difference is that this board separator assembly employs only one driver disc cutter and one driven disc cutter.
Included in the board separator assembly 50 are a base slab 51 and two upstanding side plates 52 and 53 mounted thereupon. Affixed to each of the side plates 52 and 53 are a driver shaft 54 and a driven shaft 55. A disc cutter 56 is mounted to the driver shaft 54 and a disc cutter 57 is mounted to the driven shaft 57. Also mounted on the two upstanding side plates 52 and 53 is a transporter 60 for carrying a printed circuit board through the cutting edge formed by disc cutters 56 and 57.
The transporter 60 includes indexing pins 61 through 64 for mating with openings provided generally at the end or sides of a partitioned circuit board for correct positioning of the circuit board in the board separator assembly. A recessed area 65 on the transporter 60 also allows for the board to be inserted without the surface mounted components on the bottom thereof contacting the transporter 60. The transporter 60 also includes a slot 66 that provides clearance for the outer rim of the disc cutter 56 to project through as the transporter is moved over this disc cutter.
Directional guidance for the transporter 60 is provided by a rod 68 which is attached to one side of the transporter throughout its length. This rod 68 secures the transporter and transverses through two linear ball bearings 69 and 70 embedded in the upstanding side plate 52. As in the board separator assembly of FIG. 1, movement of the transporter 60 is also limited in a direction perpendicular to the direction of translation by upper and lower roller guide pins (not shown) mounted in the upstanding side plate 53. The driver shaft 54 and driven shaft 55 are also mounted in the side plates 52 and 53 by roller bearings with limiting collars 71 through 73 securing both ends of the driven shaft 55 and one end of the driver shaft 54 to the side plates 52 and 53. Drive 75 secures the other end of the driver shaft and also provides for rotating the driver shaft and therefore the driver disc cutter 56. An adjustable tongue and groove assembly in both of the side plates 52 and 53 allows adjustment of the height of the driven shaft 55. Adjusting screws 73 and 74 respectively cooperate with compression springs (only spring 79 is shown) disposed in the side plates 52 and 53. These screws and springs determine the spacing of the driven shaft 55 such that the spacing between the driver disc cutter 56 and the driven disc cutter 57 is only a few thousandths of an inch apart. End caps 76 and 77 respectively retain the tongue and groove assemblies in side plates 52 and 53.
Shown in phantom in FIG. 5 along with the board separator assembly 50 is a partitioned printed circuit board partially separated and being moved in a direction indicated by the arrow A. The through-hole components as shown on the top surface of this board are attached prior to the board separation process. The surface mounted components (not shown) are also attached to the bottom of the board prior to this separation process. Engagement of this printed circuit board by the driven disc cutter 57 and the driver disc cutter 56 is by advancing the transporter 60 until the driven disc cutter 57 and the driver disc cutter 56 engage the board typically in a grooved portion thereof. It is this grooved portion that partitions the circuit board into the individual circuit boards. From this point on, advancement of the transporter is via the drive 75 rotating the driver shaft 54 and therefore the driver disc cutter 56. Because of the very close spacing between the two opposed discs, the circuit board is gripped between the discs and advances as the driver disc cutter 56 rotates. The driven disc cutter 57 turns freely and provides the opposed force necessary for cutting the board. The board is thus separated as it passes between the driver and driven disc cutter in the same manner of operation of the board separator assembly of FIG. 1.
Obviously, many 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.
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A device separates attached multiple printed circuit boards without damaging solder connections and delicate surface mounted components attached to the boards. The device comprises a pair of disc cutters positioned in opposed alignment and minimally spaced apart for providing a bifurcated cutting edge through which commonly attached sections of the printed circuit boards are conveyed while supported by a transporter. The contact pressure on the boards is limited to the commonly attached sections as they are engaged and conveyed by the cutting edge. Minimal stress and vibrations are imparted to the boards and therefore the components connected thereon with this device. The boards are thus separated while avoiding damage to the solder connections or the surface mounted components.
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BACKGROUND TO THE INVENTION
[0001] This invention relates to a circular saw blade, and an improved method for making the same.
[0002] The fabrication of a circular saw blade, particularly a tungsten carbide tipped blade, is a time consuming and expensive process.
[0003] The circular saw body is made from carbon steel and more recently stainless steel. One of the major problems that must be overcome is the tendency for the blade to be or become “out of flat” (warped) which can result in vibration and associated poor cutting during high-speed operation of the blade. This often occurs because of the stresses inherent in the metal blank or the various processes involved in manufacturing the blade that often includes the use/application of concentrated localised heat. The problem is often more acute in a blade that is thin (1 millimetre or less in thickness).
[0004] Clearly, it would be advantageous if a method could be found to produce a circular saw blade, particularly a thin tungsten carbide tipped blade, that is substantially flat and resistant to warping both subsequent to manufacture or in use.
SUMMARY OF THE INVENTION
[0005] It is believed that the present invention provides for these objectives and preferably includes further advantages.
[0006] The invention provides a method of manufacturing a tungsten carbide tipped circular saw blade characterised by the steps:
[0007] (a) supplying a sheet steel strip or blank to a laser cutting machine;
[0008] (b) laser cutting an arbor and the periphery profile of the blade according to a predetermined computer controlled pattern;
[0009] (c) pressing a rib pattern into the blade;
[0010] (d) brazing the tungsten carbide saw tips at respective locations on the periphery of the blade; and
[0011] (e) grinding the final cutting profile to each of the tungsten carbide tips.
[0012] In a preferred method, the following step is performed prior to step (b):
[0013] (f) passing said sheet steel strip or blank through a leveller to take camber (coil set out) out of the strip.
[0014] The rib pattern of step (c) is preferably a multi-start spiral or radial or concentric ring pattern. The sheet steel strip or blank is preferably stainless steel, expediently pre-hardened 304 and 301 stainless in a thickness of 0.6 mm to 2.5 mm. Expediently, the blade bodies are of a diameter from 88 mm to 250 mm (3.5 inches to 10 inches). Optionally the laser may also cut heat expansion slots/patterns at the time of manufacture.
[0015] In the case where the material chosen for the blade is stainless steel, then an additional step is performed after step (d).
[0016] (g) electropolishing the blade to remove brazing residues and heat discolouration from the surfaces.
[0017] In a preferred method, the process of step (b) is performed with the aid of nitrogen gas to provide a clean non-carbonised cut.
[0018] The invention also provides a tungsten carbide tipped circular saw blade when made in accordance with the method described above.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] [0019]FIG. 1 is an elevational view of a circular saw body according to the invention;
[0020] [0020]FIG. 2 is a sectional view taken along line A-A.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0021] Referring to FIGS. 1 and 2, the blade is provided with a plurality of ribs R pressed into the body to add additional wall strength and to flatten the blank saw body. The strengthening rib pattern is preferably a multi-start spiral or radial or concentric ring pattern in an alternating pattern, that is, one rib protrudes from the surface on one side whilst the adjacent rib protrudes from the surface on the other side (see FIG. 2). It is believed that the ribs also enhance the appearance of the finished saw blade.
[0022] Furthermore ribs R, when in the form of a multi-start spiral as illustrated perform an impeller function and direct airflow to the peripheral edge when blade S is spinning in use. This air flow cools the cutting area.
EXAMPLE
[0023] The first step of manufacture involves selection of the base material, in this example coils of 300 or 400 series stainless steel which weigh, 5-10 tons and have a gauge of 0.6 mm to 2.5 mm depending the end product required. The coils measure approx. 1216 mm wide and are pre-hardened to a suitable Rockwell hardness for saw blades, typically 36-44 RC. The coils are then split down to size, stress relieved, flattened and cut into squares to approximately the size of the saw blade to be produced. This is done using multi-directional levelling rollers.
[0024] The square blanks are then checked for flatness before laser cutting takes place.
[0025] In the next step the arbor and blade periphery are cut from the stainless steel blanks using a high powered CO 2 laser using pure nitrogen as an assist gas, to give a clean non-carbonised cut. This means that there is no need to clean the saw tip pockets with a sand blaster or grinding wheel which would otherwise be necessary for the next step of brazing the carbide tips in place.
[0026] In the next step, the blades are ribbed in a press tool to add additional wall strength and to flatten the blank saw body. It is found that forming the grooves in a multi-start spiral or radial manner gives maximum cross-sectional support and provides the effect of flattening and stress relieving the blank. This step is particularly relevant as it short cuts normal manufacturing methods. Traditionally saw blades are stress relieved using expensive heat treatments to achieve flatness. The substitution of this step provides major cost savings in the manufacture of these saw blades. Additionally, it has been found that thinner wall thickness material can now be used as the ribbed bodies have additional wall strength. This reduces the cost as less material is used.
[0027] The next step is brazing the tungsten carbide saw tips onto the periphery of the saw body which is done by using proprietary automatic brazing machines suitable for saw blade production. The heat source for brazing in this case is a gas flame, but induction, TIG or even lasers can be used for this purpose. Brazing is completed using a silver based filler metal and a brazing flux to make the brazed bond good and strong.
[0028] The next step comprises the electropolishing process. This is performed at this stage to clean up the brazing marks left behind after the brazing process, and to polish the saw body to a suitable shiny finish. This process is unique to stainless steel, thus avoiding the processes associated with carbon steel that require sand blasting the brazed area and polishing or finishing mechanically, to make the saw body presentable. The carbon steel saw then requires the application of a rust preventative coating to stop corrosion. Stainless steel saws do not require these processes. The electropolishing is done by immersing the saw blades into various tanks wherein the primary tank contains an electrolyte fluid (Electropol SS 92 ). An electric current is passed through from the saw blades to the walls of the electro-tank, thus removing the brazing soot and heat marks and polishing the saws at the same time. The power source is a 300 amp low voltage rectifier.
[0029] In the next step, the tungsten carbide tips of the cleaned and polished brazed blades are ground using an automatic diamond wheel grinding machine. The reason the carbide saw tips are sharpened after electropolishing is that the electropolishing dulls the carbide, eating at the binding material in the matrix of the carbide tip. Grinding after polishing produces a shiny sharp saw tip.
[0030] The final step is inspection and packaging of the finished product.
[0031] It will be appreciated that the above description is by way of example only and alternative process steps are envisaged within the scope of the invention.
[0032] Referring to FIG. 1 of the drawings, there is shown a saw blade S having a conventional 16 mm arbor 10 and a knock out diamond shaped arbor 11 . The body is shown without Carbide teeth being brazed thereto. These are not of importance to this invention.
[0033] The diamond arbor portion 11 is retained on to the body portion by means of one, two, three, four or more tags 12 . The cutting laser cuts the diamond arbor and the tags 12 to ensure they are large enough to provide sufficient strength for the blade to function when used with the circular arbor 10 . In any event, most saws use a locking flange F (not shown), which would substantially cover the portion of the blade beyond the diamond shaped or enlarged arbor 12 so that strength of the tags is not necessarily a critical factor.
[0034] The saw body is made from steel or stainless steel sheet, preferably pre-hardened 304 or 301 stainless. The advantages of this material is that it is naturally rust resistant, and with the use of electropolishing (reverse electroplating) gives a near mirror, low friction and aesthetically appealing finish. It is surprising and unexpected that the electropolishing process removes the residue brazing fluxes, other residues and associated heat discolourations and marks.
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A method of manufacturing a tungsten carbide tipped circular saw blade (S) The method and blade are characterised by pressing a rib pattern (R) into the body of the blade (S). The rib pattern strengthens the blade body and avoids warping, particularly in thin blades, e.g. less than 1 mm thick.
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BACKGROUND OF THE INVENTION
This invention relates to an hydraulically operated impact device, e.g. rock drill, comprising a reciprocably driven hammer piston arranged to impact upon an anvil means of a tool member, a supporting member for axially supporting the tool member, and a support piston that is slidable in a cylinder and subject to the hydraulic pressure in a pressure chamber in order to bias said supporting member into a defined forward end position. The pressure chamber is connected to a source of high pressure fluid and narrow clearances between the relatively moving surfaces of the support piston and its cylinder form narrow leak passages from said pressure chamber. The support piston and the pressure chamber form a damping device that reduces the stress on the housing of the impact device by dampening the reflected shock waves that propagate from the bit of the tool rearwardly through the tool which can be the drill stem of the rock drill or the chisel of a jack hammer or the like.
An impact device of this kind is described in U.S. Pat. No. 4,073,350. Because of the tolerances, it is unavoidable that the narrow clearances vary a great deal between rock drills of the same production line. Since the leakage varies with the cube of the width of the clearances, the leakage will vary a great deal. The leakage is a loss of energy which reduces the overall efficiency of the impact device.
One object of the invention is to control the leak flow out of the dampening device and simultaneously to give the damping device long service intervals. This will be achieved by the features defined in the characterizing parts of the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a longitudinal section through the front part of a rock drill according to the invention.
FIG. 2 is a longitudinal section through the rear part of the rock drill.
FIG. 3 shows a coupling circuitry of the rock drill shown in FIGS. 1 and 2. Corresponding details have been given the same reference numeral in the various figures.
FIG. 4 shows a part of FIG. 1 on a larger scale.
DETAILED DESCRIPTION
In the figures, the rock drilling machine 10 comprises a front head 11, a cover 12, a gear housing 13, an intermediate part 14, a cylinder 15 and a back head 16. A hammer piston 17 is reciprocable within the cylinder 15. The hammer piston 17 consists of a cylindrical rod with two piston portions 18, 19 having piston surfaces 20, 21. The portion of the hammer piston which extends forwardly from the piston portion 18 is denoted by 17a, and the portion which extends rearwardly from the piston portion 19 is denoted by 17b. The rod portion between the rod portions 18, 19 is denoted by 17c.
The piston portion 17a is arranged to deliver impacts against an adapter 22, which is intended to be connected with a drill string (not shown). A rotation chuck 23 is rotatably journalled in the gear housing 13 by means of roller bearings 24, 25. The rotation chuck 23 is provided with a gear ring 26 which cooperates with a gear wheel 27. A driver 28 transmits the rotation of the rotation chuck 23 to the adapter 22. The inner and outer surface of the driver or chuck bushing are out of round. The adapter 22 is thus non-turnably guided in the driver 28; but is axially movable, however, relative to the driver. The forward end of the adapter 22 is journalled in the front head 11 by means of a guide 29 and a ball bearing 30. Flushing fluid is supplied to the axial hole of the adapter 22 and the drill string through a flushing head 31. A stop ring 32 is mounted between the flushing head 31 and the driver 28. A support bushing 33 is inserted in the rear portion of the rotation chuck 23. The support bushing 33 is provided with a collar 34 adapted to rest against a rear end surface of the rotation chuck 23.
The gear wheel 27 is splined to a shaft 35. The shaft 35 is journalled in bushings 36, 37 in the gear housing 13. The shaft 35 is rotated by means of a hydraulic motor 38 attached to the cylinder 15.
As seen in FIG. 3, a rear annular pressure chamber 39 is defined by the cylinder 15, the rod portion 17b, the piston surface 21 on the piston portion 19, and the front surface of a sealing ridge 40. A forward annular pressure chamber 43 is defined in the same way by the cylinder 15, the rod portion 17a, the piston surface 20 on the piston portion 18, and the rear surface of a circular sealing ridge 44.
A distributing valve in the form of a slide 46 is supplied with pressurized hydraulic fluid through a supply conduit 47. An accumulator 48 is continuously connected to the supply conduit 47. On the one hand, the accumulator 48 discharges an instantaneously increasing pressurized hydraulic fluid flow during the working stroke of the hammer piston 17, and on the other it receives a certain amount of hydraulic fluid before the hammer piston has reversed upon the slide shift at the extreme positions. The supply conduit 47 leads to an annular inlet chamber 49 in the cylinder of the distributing valve. The cylinder of the valve has also two annular outlet chambers 50, 51 to which return conduits 52, 53 are connected. These return conduits lead to a non-illustrated sump from which a non-illustrated positive displacement pump sucks hydraulic fluid so as to supply the supply conduit 47 with a constant flow of pressurized hydraulic fluid through a non-illustrated control valve. An accumulator 54 is continuously connected to the return conduits 52, 53. The accumulator 54 shall prevent pressure shocks from arising in the system. The accumulators 48, 54 equalize the highly fluctuating need of pressurized hydraulic fluid of the impactor during the cycle of impacts and also equalize the pressure peaks.
With the slide 46 in its left-hand end position (FIG. 3), pressurized hydraulic fluid is supplied to the rear pressure chamber 39 through a combined supply and drain passage 55 while the forward pressure chamber 43 is drained through the return conduit 53 through another combined supply and drain passage 56. With the slide 46 in its non-illustrated right-hand end position, pressurized hydraulic fluid is instead supplied to the forward pressure chamber 43 through the passage 56 while the rear pressure chamber 39 is drained through the passage 55.
The slide 46 has extending end portions 57, 58, the end surfaces 59, 60 of which are acted upon by the pressure in control passages 61, 62 which terminate in the cylinder wall of the hammer piston 17. The end portion 58 has an annular piston surface 63 which is acted upon by the pressure in the passage 55 through a passage 64 in the slide 46. The end portion 59 has a similar piston surface 65 which is acted upon by the pressure in the passage 56 through a passage 66 in the slide 46. The piston surfaces 63, 65 constitute holding surfaces and are therefore of smaller area than the end surfaces 59, 60 which constitute shifting surfaces. A passage 74 is connected to sump so as to drain the space between the piston portions 18, 19. Thereby, one of the control passages 61, 62 will always drain through this passage 74 when the other one of these control passages is supplied with pressurized hydraulic fluid.
The control passage 61 has four branches which terminate in the cylinder wall of the hammer piston 17. The reference numeral 61a denotes one of these branches. One or several of these branches can be blocked by means of an exchangeable regulator plug 67. By this arrangement the rear turning point of the hammer piston 17 and thereby the piston stroke can be varied, which means that a various number of strokes and percussion energy per blow can be obtained.
A retard piston 68 is displaceably and rotatably guided in the intermediate part 14. A piston surface 69 on the retard piston defines a movable limitation wall of a retard or cushioning chamber 70. The retard chamber 70 is limited rearwards by a surface 73 in the machine housing. The retard chamber 70 communicates with the supply conduit 47 and the accumulator 48 through a passage 71. The feeding force applied to the rock drill 10 is transferred to the drill string via the pressurized hydraulic fluid in the retard chamber 70. Preferably, the piston surface 69 on the retard piston 68 and the accumulator 48 are dimensioned so that the force acting forwardly on the retard piston 68 substantially exceeds the feeding force. By such a dimensioning, the position in which the adapter 22 and thus the work tool is situated when the hammer piston hits the adapter remains unchanged independently of variations in the feeding force. This forwardly-acting force is transferred to a surface 72 on the cover 12 via the collar 34 of the rotation chuck bushing 33, the rotation chuck 23 and the thrust bearing 24.
The operation of the rock drill will now be described with reference to the figures.
Assume that the slide 46 is in the position shown in FIG. 3, so that the rear pressure chamber 39 is supplied with pressurized hydraulic fluid and the forward pressure chamber 43 is evacuated. Assume also that the hammer piston 17 is moving forward. The regulator plug 67 blocks the two right branches of the control passage 61. In the position in which the hammer piston 17 is in FIG. 3, the control passage 62 is being drained through the draining passage 74 and the control passage 61 has been drained through the forward pressure chamber 43 until the piston portion 18 covered the branch 61a. The slide 46 is positively retained in its position because the pressure in the supply conduit 55 is transmitted to the holding surface 63 of the slide. When the hammer piston 17 moves forward (to the left in FIG. 3), the control passage 61 is again opened so as to drain now into the draining passage 74. Then, when the piston portion 19 passes the port of the control passage 62, it opens the port to the rear pressure chamber 39 from which the pressure is conveyed through the control passage 62 to the end face 60 of the slide. Now, the slide shifts to its non-illustrated second position (to the right in FIG. 3) so that the forward pressure chamber 43 is pressurized while the rear pressure chamber 39 is drained. This takes place just before the hammer piston strikes the adapter 22. The slide 46 is positively retained in its right-hand position because the pressure in the supply conduit 56 is conveyed to the holding surface 65 of the slide. The control passage 62 is already in communication with the drain passage 74 when the piston surface 20 of the piston portion 18 passes the branch passage 61a of the control passage 61 so that the pressure in the forward pressure chamber 43 is transmitted through the control passage 61 to the end face 59 of the slide. The slide 46 shifts therefore to its left-hand position shown in FIG. 3 where it remains as previously described because of the fluid pressure upon the holding surface 63. Pressurized hydraulic fluid is now supplied through the inlet 47 to the rear pressure chamber 39 and the hammer piston 17 retards due to the hydraulic fluid pressure upon the piston surface 21. Now, the accumulator 48 receives the hydraulic fluid forced out from the pressure chamber 39 because of the movement to the rear of the hammer piston 17 which decreases the volume in the pressure chamber 39. The accumulator 48 is supplied with pressurized hydraulic fluid also during the first part of the work stroke. However, when the hammer piston 17 reaches the speed that corresponds to this supplied flow, the accumulator 48 starts supplying pressurized hydraulic fluid to the pressure chamber 39 and thus further increases the speed of the hammer piston 17.
When a feeding force is applied to the rock drilling machine 10, the adapter 22 will be biased against the rotation chuck bushing 33. The rotation chuck bushing 33 will be retained in its position shown in FIG. 1 because the forward-acting force on the retard piston 68 exceeds the feeding force. Therefore, when the feeding force is applied, the contact surface 72 will only be unloaded.
When the drill string and the adapter 22 recoils from the rock, during operation of the rock drilling machine, the adapter 22 strikes against the rotation chuck bushing 33. The recoil pulses are transmitted to the retard piston 68 and further to the pressurized hydraulic fluid in the retard chamber 70, and the fluid works as a recoil pulse transmission member. The accumulator 48 or other suitable spring means is constantly connected to the fluid cushion by means of the hydraulic fluid column in the passage 71. If the recoil force exceeds a certain value, the rotation chuck bushing 33 and therefore also the retard piston 68 are lifted out of contact with the rotation chuck 23. By this arrangement the influence of the recoil on the rock drilling machine 10 is damped. The adapter 22 and the drill string are then returned by means of the pressure in the retard chamber 70 to the position which is independent of the feeding force.
The rotation of the rotation chuck 23 and the adapter 22 is transmitted to the retard piston 68 by means of the rotation chuck bushing 33. The pressurized hydraulic fluid in the retard chamber 70 thus provides a thrust bearing for the adapter 22 and the drill string.
Narrow clearances 75, 76 are formed between the relatively moving surfaces (rotation and axial movement) of the support piston 68 and its cylinder that is formed in the intermediate part 14 of the housing. These clearances 75, 76 form narrow leak passages from the pressure chamber 70. In annular grooves 77, 78 at the outer ends of the clearances there are sealing rings 79, 80 (FIG. 4), and passges 81, 82 lead from the inner sides of the grooves 77, 78 to a passage 83 in which there is a replaceable screw 84 with a through bore that forms an orifice restrictor. A passage 85 leads off the leakage oil to the outlet passages 52, 53. Thus, the two clearances 75, 76 form two restrictions that are connected in parallel with each other and connected in series with the orifice restrictor 84. The restrictor 84 is a sharp edge orifice nozzle, that is, a nozzle that has a sharp inlet edge.
It is advantageous to have a small leakage out of the pressure chamber 70 since the leakage oil removes heat from the pressure chamber. The leakage should, however, not be too big since the leakage is a loss of energy. The described combination of the restrictions 75, 76, 84 has two main advantages; it makes the changes in leakage flow relatively small when the viscosity changes and it reduces the impact of the actual width of the clearance upon the leakage flow. If the viscosity is reduced, the flow through the clearances 75, 76 increases, and because of the increased flow which has to pass through the orifice restrictor 84, the pressure drop across the orifice restrictor 84 increases. Thus, the pressure drop across the clearances 75, 76 decreases and the decreased pressure drop tends to reduce the flow through the clearances. As a result, the increase in leakage flow will be comparatively small.
In practice, the actual clearances will vary from rock drill to rock drill because of the tolerances. Because of the orifice restrictor 84, the variations in leakage flow between the drills will be comparatively small also when the clearances will vary a great deal. In a rock drill in which the width of the clearances was 0.015 mm and the orifice 84 had a diameter of 0.5 mm, the leakage flow was 1.2 liters/min. When the width of the clearances was doubled, the leakage flow increased to 1.7 liters/min which is a very small increase.
In the pressure chamber 70, there is the normal pump pressure which is usually above 200 bar, but pressure peaks occur which are several times higher. These peaks will occur even when the passage 71 between the chamber 70 and the accumulator 48 is short, straight and wide as shown in FIG. 1 since the pressure build-up is very rapid. The pressure peaks will, however, dampen out in the clearances so that the sealing rings 79, 80 will not have to stand the excessive peak pressure. The pressure applied to the sealing rings is the pressure in the passage 83, which is lower than the pressure in the pressure chamber 70.
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In an hydraulic rock drill there is an hydraulic so called recoil damper that damps the reflected shock waves that propagates from the rock backwardly through the drill stem. The damper comprises a support piston (68) slidably in a cylinder so that a pressure chamber (20) is formed in which the support piston has a piston area. Narrow clearances (75,76) between the support (68) and its cylinder form leak passages and these leak passages are coupled in series with an orifice restrictor (84) to sump. The pressure peaks in the pressure chamber do not reach sealing rings located at the outer portions of the clearances.
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FIELD OF THE INVENTION
This invention is concerned with transport carts, particularly of the type used in industrial-commercial applications for movement of articles, preferably those loaded on pallets. The cart is particularly designed for use as a single transport vehicle or as one of a plurality of carts organized as a train and designed to accurately track and follow the propelling vehicle. Carts of this type must be capable of withstanding heavy loads and substantial abuse because of the operating environment for which they are designed. Vehicles of this type are used for transporting materials and articles in process throughout a plant or for movement of articles in a warehouse. In this connection, it is sometimes desirable that the carts be loaded on another vehicle or themselves placed in storage while fully loaded. It is sometimes necessary to move them from one level to another and this may be necessary even when the carts are loaded. For this purpose, it is important that the carts be capable of being lifted and moved by means such as a forklift truck. To withstand this type of use, the vehicles must be strong and should be so designed that there is no interference with the tines of such devices as a forklift truck. Further, it is desirable that they be of low silhouette so that they will not occupy valuable vertical space when used for storage purposes and will have a low center of gravity when used for transport. It is also important that the vehicles be so designed that they will accurately follow a towing vehicle, permitting one or more of the carts, when arranged in tandem, to navigate narrow aisles and to make turns from one aisle into another where the turning radius is very restricted.
A BRIEF DESCRIPTION OF THE INVENTION
The cart of the invention includes a platform mounted on swivel casters. The platform itself is a sandwich of two spaced panels with each panel having offset, rib-like or pan-like portions which position the main portions of the panels at a substantial spacing and provide areas where the panels are in contact with each other. At the areas of contact, the panels are rigidly joined as by welding to form a high-strength, rigid, unitary platform. The casters are recessed into this platform from beneath, whereby the platform is of low silhouette and thus has a minimum of ground clearance. The peripheral edges of the panels are bent downwardly to provide a rigid beam structure surrounding the platform to give it substantial strength and to provide a downwardly opening recess within which is mounted a linkage for controlling the swivel movement of the casters. Between the front and rear casters the interconnecting member of the linkage is recessed within the silhouette of the sides of the platform providing a clear area where the tines of a forklift may be inserted beneath the platform to lift it without interference with the caster-connecting linkage. The linkage is arranged in such a way that the cart will accurately track and precisely follow the towing vehicle ahead and thus can navigate corners of restricted radius.
The invention provides a platform having a smooth upper surface except for a pair of recessed wells which serve the dual function of strengthening and stiffening the platform and also permitting pallets of various sizes and leg configurations to be mounted on the platform. As constructed, the center of the platform provides a flat surface for receiving one or more flat bottom objects or pallets while the recesses permit the platform to receive one or more pallets having depending feet on their corners. Because the surface and sides of the platform are formed from a single sheet of material without joints, the platform provides a surface which resists collecting dirt and which may be readily washed and cleaned. This is particularly important when the carts are used in sensitive manufacturing processes such as precision electronics, pharmaceuticals, or the handling of dangerous chemicals.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the transport cart of this invention;
FIG. 2 is an exploded, perspective view of the basic components of the cart;
FIG. 3 is a sectional, elevation view taken along the plane III--III of FIG. 2;
FIG. 4 is a sectional, elevation view taken along the plane IV--IV of FIG. 2;
FIG. 5 is a bottom view of the transport cart of this invention omitting details of lower panel for clarity;
FIG. 6 is a sectional, elevation view taken along the plane VI--VI of FIG. 5 omitting front caster for clarity;
FIG. 7 is an enlarged, fragmentary view taken along the left-hand end of the plane VI--VI of FIG. 5; and
FIG. 8 is a sectional, elevation view taken along the plane VIII--VIII of FIG. 6.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIG. 1, the numeral 10 identifies the transport vehicle having a platform 11. As seen in FIGS. 2, 6 and 7, the platform 11 is, in effect, a sandwich made up of an upper panel 12 and a lower panel 13. The platform 11 is supported on four casters, two front casters 14 and two rear casters 14a. These casters are interconnected by a linkage 15.
The top panel 12 consists of a single sheet of material having a planar portion 20 and a pair of recessed wells 21. The panel has a depending flange 22 forming its periphery and extending entirely around the panel. The flange has an upper, outwardly inclined portion 23, a vertical portion 24 and a horizontally extending footpiece 25. The flange 22 provides a stiffening support for the panel 12 entirely surrounding the panel.
The two recessed wells 21 extend substantially the full width of the top of the panel and are recessed only a minor portion of the height of the side flanges 22. These recessed areas 21 are spaced apart and positioned adjacent the front and back of the panel and provide a receiving area for pallets of various sizes and having depending legs. They also serve the dual purpose of stiffening and reinforcing the panel 12.
The panel 13 also has a planar portion 30 surrounded by a depending flange 31 which has a horizontally extending footpiece 32 at its lower end. The size of the panel 13 is such that when the panel 13 is nested within the panel 12, the footpiece 25 of the panel 12 seats on the footpiece 32 of the panel 13 and the edges of the two footpieces are in the same vertical plane (FIGS. 6, 7 and 8). The panel 13 has a plurality of parallel, raised ridges 34 extending in a front-to-back direction. In addition, the panel 13 has a plurality of parallel depressed channels 35 also extending in a front-to-back direction. The tops of the ridges 34 and the bottoms of the channels 35 are flattened. Both the channels and the ridges are long, narrow structures which, in the case of the channels, extend substantially the full length of the lower panel 13. The ridges 34 are shorter and designed to seat between the front and back recessed wells 21 of the upper panel 12 when the two panels are sandwiched together. When the lower panel 31 is nested within the bottom of the upper panel 12, the tops of the ridges 34 seat against the undersurface of the planar area 20 of the upper panel and the bottoms of the recesses 21 seat against the upper surface of the planar portion 30 of the lower panel 13 (FIGS. 6 and 8). Where the panels are thus in contact, the panels are permanently and rigidly joined together. If the panels are fabricated from metal, such as steel, the panels are welded together in their areas of contact. If the panels are fabricated of a reinforced resin material, they will be bonded together at these points. In either case, the result is a sandwich structure in which the planar portions 20 and 30 of the panels are spaced apart the height of the ridges 34 and the recessed areas 21 to provide a very rigid, strong structure capable of standing high unit loading without deflection. The ridges 34 and channels 35 brace the platform against deflection in a lengthwise direction and the wells 21 brace the platform against transverse deflection.
The recessed wells 21 are each provided with a pair of holes 27 which permit water or other liquids to drain from the wells. This is particularly useful when the carts are scrubbed down to clean them. The holes 27 are aligned with the holes 37 in the lower panel so the liquids will pass entirely through the platform. Additional drain holes 38 are provided at each end of the central channel in the event any liquid accumulates in this area.
The peripheral flange of the cart is surrounded by bumper strip 39 of a suitable resilient material such as vinyl or rubber (FIG. 6). The strip 39 is secured by suitable means such as adhesive; is seated up and projects beyond the edge of the footpieces 25 and 32. It provides a cushion in the event of collision between the cart and an object to prevent, or at least lessen damage to either the cart or the object.
At each of the four corners of the lower panel, areas are provided to mount the casters 14 and 14a. This is best seen in FIG. 7. To mount each of the casters, depending weld-screws or studs 48 are welded to the lower panel to secure the mounting plates 41 of the casters. The lower surface of the lower panel in the four areas where the casters are mounted is substantially in the plane of the bottom surface of the wells 21 of the upper panel (FIG. 7). This is substantially above the bottom of the peripheral flanges of the platform for reasons which will be explained subsequently.
Each of the casters has a yoke 42 which is free to rotate about its vertical axis (FIG. 5). Each of the yokes is attached to a strap 43 which projects outwardly away from the pivot axis of the caster.
The straps 43 attached to the casters 14 at the front of the vehicle extend inwardly and rearwardly. The straps 43a attached to the casters at the rear of the vehicle extend inwardly and forwardly. The straps 43 for the forward casters, at their rearward, inner ends are connected by a cross link 44. The straps 43a for the rear casters at their forward ends are connected by a cross link 45. The cross link 44 is connected to the rearward end portion 46a of a tow bar 46. The tow bar also has a forward portion 46b connected to the rearward portion 46a by a hinge 47. The rearward portion 46b of the tow bar is positioned immediately beneath the bottom of the peripheral flange of the platform which forms the forward end of the platform and is pivotally connected to the platform by the stud 48 at a point substantially forward of the connection between it and the cross link 44. The connection between the tow bar and the cross link 44 is by means of the pin 49 which engages the cross link 44 by extending through the slotted opening 50. This provides a lost motion connection to accommodate the arcuate travel of the pin 49 as the tow bar is pivoted about the stud 48. The tow bar is also supported by the bracket 51. At the hinge 47, the forward end 46b of the tow bar is biased into an erected position by a spring 52, which normally holds the tow bar against the stop 53 (FIG. 6).
An arm 60 centered about the pivot stud 48 is rigidly secured to the rear portion 46b of the tow bar and projects to one side where it is pivotally connected at its outer or free end to the tie link 61. The rearward end of the tie link is pivotally connected to the pivot plate 62 at 63. The pivot plate, in turn, is pivotally secured to the platform by the pivot stud 64. The spacing between the pivot stud 64 and the point of pivotal connection between the tie link 61 and the pivot plate 62 is the same as the distance between pivot stud 48 and the pivotal connection between the end of the arm 60 and the tie link 61. The pivot plate 62 has a pin 65 which engages a slot 66 in the cross link 45. The spacing of the pin 65 from the pivot 64 is slightly greater than the spacing of the pin 49 from the pivot bolt 48. As the tow bar pivots to the left or the right, casters on the same side of the cart pivot through the same arc, about 18° on the outside of the turn and about 29.6° on the inside. This produces a turning radius for the cart of about 70 inches.
Because of the arrangement of the levers, when the tow bar is pivoted clockwise, as seen in FIG. 5, the casters 14 at the front end, will also be pivoted clockwise, whereas the casters 14a at the rear end of the platform will be pivoted counterclockwise. This results in the cart, in effect, rotating about its midpoint as it turns a corner. This is very important in enabling the cart to navigate sharp turns of limited radius, such as often occur in industrial and commercial facilities where one aisle joins another.
It will be noted from FIG. 6 that the tie link 61 is recessed up into the platform well above the lower edge of the peripheral flanges of the platform. Thus, it will not interfere with the tines of a forklift passing under the cart between the front and rear casters.
At the rearward end of the platform, a towing bracket 70 is secured to the platform and extends rearwardly out beyond the rear of the platform. This towing bracket is equipped with a hook 71 welded to its upper surface and designed to engage the loop at the forward end of the tow bar of the next following cart (FIG. 6).
The top panel, if fabricated from steel or aluminum, can be coated with suitable material such as vinyl to prevent rust and to facilitate cleanliness. When the panel is so coated, it can be easily cleaned as with a hose. The holes in the recessed wells 21 provide drains for this purpose.
Other linkage constructions for controlling the steering characteristics of the vehicle may be substituted for that specifically described in this invention, provided the mechanism interconnecting the front and rear wheel assemblies is sufficiently recessed within the vertical silhouette of the platform that it will not interfere with the lifting of the truck from beneath by means which seat against the platform between the front and rear wheels.
The sandwich construction for the cart provides a high-strength, deflection resistant panel of relatively thin construction, permitting it to have a low silhouette. This, coupled with the recessing of the casters and caster control mechanism, makes the truck particularly useful for both transport and storage. The construction also makes it versatile because it can safely and effectively handle pallets and other types of loads having a wide variety of designs and construction. It is also adapted to economical manufacture. The platform is particularly adapted to automated fabrication and even if not fully automated, involves a low labor factor for assembly. Being an integrated structure with only the tow bar and the towing bracket projecting, it is much less likely to be injured or to cause injury.
The rounded corners which are possible with the unitary construction involved also contribute to the elimination of injury to objects and personnel. Because both sides and the rear are free of obstructions, the cart can be loaded and unloaded from either side or the rear.
Having described a preferred embodiment of this invention, it will be recognized that various modifications of the invention may be made. Such of these modifications as do not depart from the principles of the invention are to be considered as included in the hereinafter appended claims, unless these claims, by their language, expressly state otherwise.
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A transport cart is disclosed having a load receiving and supporting platform of sandwich-type construction formed from a pair of spaced panels each having offset portions which contact the other panel. The panels, where they contact each other, are rigidly secured together to form a rigid, load supporting sandwich. The platform is mounted on swivel casters interconnected by a linkage system which responds to the pivotal movement of the tow bar and which effects opposite pivotal movement of the front and rear casters to cause the cart to track the towing vehicle.
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This is a continuation of application Ser. No. 969,746, filed Dec. 14, 1978 now abandoned.
BACKGROUND OF THE INVENTION
This invention relates to the treatment of superphosphoric acid and more particularly refers to an improved process for removing magnesium from wet process superphosphoric acid.
Wet process phosphoric acid is conventionally prepared by reacting sulfuric acid and phosphate rock, followed by filtration to remove the insoluble gypsum and other insoluble compounds. The resultant dilute or weak phosphoric acid containing about 26 to 30 percent P 2 O 5 by weight is commonly known as "filter" acid and is a highly impure material containing dissolved sulfates, fluosilicates, and salts of iron, aluminum, magnesium, sodium and other metals. These impurities may precipitate and settle out in varying rates and amounts during storage or further processing of the dilute wet process phosphoric acid.
Concentration of dilute or weak wet-process phosphoric acid up to the super range containing 64 to 72 percent P 2 O 5 is done in two steps. Preferably this two step concentration is done in separate equipment because of variation in temperature, corrosion and viscosity that occur through the total range.
As a first step, it is common to evaporate said dilute or weak acid and to partially purify said acid by removal of precipitated impurities consisting of CaSO 4 , Na 2 SiF 6 , (Fe, Al) 3 KH 14 (PO 4 ) 8 .4H 2 O and other salts to a concentration of about 38 to about 56 weight percent P 2 O 5 . This acid is known as "evaporator" acid with about 54 percent P 2 O 5 being most common. It is difficult to remove magnesium at this stage due to the high solubility of magnesium salts.
As a second step, the partially purified evaporated acid (38 to 56 weight percent P 2 O 5 ) is further evaporated to superphosphoric acid containing about 64 to 72 weight percent P 2 O 5 . Impurities that precipitate in the production of the superphosphoric acid consist of MgH 2 P 2 O 7 , FeH 2 P 3 O 10 , AlH 2 P 3 O 10 and other salts. Filtration of superphosphoric acid removes a portion of the magnesium, iron, and aluminum impurities, but such filtration of the superphosphoric acid is a difficult and slow process. The filtration rate is very slow, due to the high viscosity of the superphosphoric acid and the small crystals that have dimensions in the range of 1 to 15 microns.
Liquid ammonium phosphate fertilizer solutions are derived from wet process phosphoric acid. Said solutions, commonly 10-34-0 grade (10 weight percent N, 34 weight percent P 2 O 5 , and 0 weight percent K 2 O), are prepared either (1) by reacting superphosphoric acid containing 64-72 percent P 2 O 5 with liquid and/or gaseous ammonia or (2) by reacting acid containing 54 to 60 weight percent P 2 O 5 with gaseous ammonia. Magnesium is a particularly troublesome impurity in such prepared liquid ammonium fertilizer solution because it slowly precipitates as Mg (NH 4 ) 2 P 2 O 7 .4H 2 O or as MgNH 4 PO 4 .6H 2 O. The settling of these precipitates results in sludge losses in storage tanks or plugging of handling equipment.
Various prior art methods have previously been proposed for limiting precipitation of the magnesium salts or for removing magnesium from phosphates.
One method, described in U.S. Pat. No. 3,632,329, teaches a method for preventing post-precipitation of magnesium salt from ammonium phosphate fertilizer base solutions prepared from wet superphosphoric acid by the accelerated precipitation of Mg (NH 4 ) 2 P 2 O 7 .4H 2 O. The method comprises continuous agitation of said solution concurrently with seeding at specified temperatures and pH followed by separation of the precipitated magnesium sludge.
A second method, described in U.S. Pat. No. 3,554,728, teaches the accelerated precipitation of Mg(NH 4 ) 2 P 2 O 7 .4H 2 O in said solutions by means of overammoniation to high N/P 2 O 5 ratio followed by separation of the sludge and adjustment back to the desired N/P 2 O 5 ratio.
The disadvantage of these methods is that disposal or by-product use of the magnesium sludge containing valuable fertilizer P 2 O 5 and N can be very costly.
A third method, described in U.S. Pat. No. 3,642,439, involves forming a precipitate of a magnesium-aluminum-fluoride-phosphate complex compound from phosphoric acid. The process involves the following steps:
(a) evaporating the weak phosphoric acid at a temperature of 85°-100° C. at a pressure below atmospheric to a concentration of 45-53 weight percent P 2 O 5 , preferably 47-51 weight percent P 2 O 5 , whereby the H 2 SiF 6 content of the acid is reduced and the hydrogen fluoride content is increased;
(b) maintaining the hydrogen fluoride content of the concentrated phosphoric acid at F/MgO weight ratio of at least 2.2, preferably between 3 and 12;
(c) maintaining the soluble aluminum content of the concentrated phosphoric acid, measured as Al 2 O 3 , at an Al 2 O 3 /MgO weight ratio of at least 1.4, preferably between about 3 and 12;
(d) maintaining the concentrated phosphoric acid at 50°-100° C. for 15-40 hours to form a precipitate comprising a crystalline filterable magnesium-aluminum-fluoride-phosphate complex compound; and
(e) separating the precipitate from the purified concentrated phosphoric acid. The additives required for this process are costly.
A fourth method, described in U.S. Pat. No. 3,711,268, relates to adding a soluble fluorine compound to ammoniated superphosphoric acid to partially precipitate the magnesium impurities or partly stabilize the liquid. This method has the drawback that the fluoride reagent is very costly. A similar method utilizes less costly 23 percent by weight H 2 SiF 6 to precipitate MgSiF 6 .6H 2 O from phosphoric acid, but costs are still relatively high considering dilution cost and cost of H 2 SiF 6 .
Another method involves pretreating phosphate ore prior to conventional sulfuric acid leaching by leaching with an acidic solution to dissolve the magnesium impurities. But many phosphate rocks cannot be leached to a sufficiently low magnesium content.
The process of the present invention overcomes the shortcomings of prior art processes for removing magnesium from superphosphoric acid.
SUMMARY OF THE INVENTION
An object of the present invention is the efficient and economical separation of magnesium from wet process superphosphoric acid. Another object of the invention is the growth in the superphosphoric acid of magnesium-containing crystals that are easily separable. A further object of the invention is the production of a purified wet process superphosphoric acid by the removal of a substantial portion of the magnesium from said acid.
It has been discovered that it is possible to precipitate magnesium from wet process superphosphoric acid in the form of crystal agglomerates that are easily separated by filtration by the process herein described. The magnesium compound in the crystal agglomerates is MgH 2 P 2 O 7 .
DETAILED DESCRIPTION OF THE INVENTION
This invention is directed to a process for separating magnesium from wet process superphosphoric acid.
Firstly, wet process superphosphoric acid containing (1) about 62 to about 72 percent by weight P 2 O 5 with about 10 to about 45 percent, more preferably with about 25 to about 35 percent of the P 2 O 5 in polyphosphate form, and (2) about 0.5 to about 3.0 percent by weight MgO is aged under time and agitation conditions hereinafter specified.
The acid is aged for about 4 to about 180 hours, more preferably about 8 to about 36 hours at a temperature of about 85° to about 180° C., more preferably about 105° to about 140° C. at atmospheric pressure. During the aging step, it has been found critical that no agitation or "intermittent agitation" of the superphosphoric acid should occur.
By the term "intermittent agitation", it is meant that agitation of the aging acid should occur at least once for up to about 50 percent of the aging time period. Preferably a time period of such agitation at least once for about 2 to about 30 minutes per 8 hours of aging should occur or in other words such agitation should occur preferably for about 0.4 to about 6 percent of the aging time period.
Although no agitation works as well as intermittent agitation, it has been found not practical in a commercial plant due to some settling of sludge in the aging vessel. Intermittent agitation gives a filtration rate almost as large as with no agitation and does not allow settling of sludge in the aging vessel.
Any type intermittent agitation can be used, such as sparging or stirring. Although any type stirring is operative, stirring at a low shear rate is preferred.
The aging step can be either a batch or continuous operation.
Secondly, such aged superphosphoric acid is filtered by conventional means at any filterable temperature preferably about 85°-180° C., more preferably at about 100° to about 130° C.
Aging of the acid under the above conditions causes crystallization of magnesium as MgH 2 P 2 O 7 and with intermittent agitation prevents sludge from settling in the aging vessel. Thus, a maximum filtration rate of such aged superphosphoric acid is achieved. No or intermittent agitation yields a greater filtration rate than continuous agitation, that is, agitation for 100 percent of the aging time. Generally, the more agitation time employed the lower the filtration rate for the aged superphosphoric acid.
Any conventional means of filtration can be used. Preferably a rotary vacuum pre-coat filter.
Preferably a coarse-grade diatomaceous earth filter aid is used in the filtration step as a pre-coat on the filter media.
DESCRIPTION OF THE DRAWING
FIG. 1 is the plot of the filtration rates of four samples of freshly produced, unfiltered superphosphoric acid prepared according to Example I vs. the cake form time in minutes. One sample was no agitation during the aging step. The second sample was given intermittent agitation. The remaining two samples were continuously agitated with a slow rake and with a moderate speed turbine.
EXAMPLE I
The phosphate rock used in this example was obtained from typical mining operations in the Western United States. The rock was acidulated with H 2 SO 4 by the conventional wet process. The dilute phosphoric acid produced was evaporated to about 51 percent P 2 O 5 and immediately centrifuged to remove a substantial portion of the solids present. The acid containing about 51 percent P 2 O 5 was further concentrated by evaporation to yield superphosphoric acid containing 68.2 percent P 2 O 5 , 28 percent of the P 2 O 5 being in polyphosphate form, 1.02 percent MgO, 1.43 percent Fe 2 O 3 , 2.62 percent Al 2 O 3 , 4.62 percent H 2 SO 4 and 0.38 percent F.
A portion of the freshly-produced superphosphoric acid was filtered, with the filtrate analyzing 1.01 percent MgO. This example teaches that most of the magnesium present in the freshly-produced superphosphoric acid is in soluble form.
EXAMPLE II
Four portions of the freshly-produced, unfiltered superphosphoric acid from Example I were subjected to aging at 118° C., each under a different condition of agitation. The aging times were varied somewhat in order to achieve nearly the same percent MgO in the final filtrate. This enables one to compare the filtration rates on an equal basis. At the end of each aging period, about half of the soluble magnesium had crystallized as MgH 2 P 2 O 7 . The acid portions were filtered at 23 inches Hg vacuum and 118° C. in a Buchner funnel using a one-half inch of a coarse grade diatomaceous earth filter aid. The funnel and filter aid had previously been prepared by saturating the filter aid with a superphosphoric acid filtrate free of solids and equilibrating at 118° C. As the aged superphosphoric acid filtered, the MgH 2 P 2 O 7 cake formed on top of the filter aid. The filtration rate achieved vs. cake form time is plotted in FIG. 1.
As can be seen, the lowest filtration rate was obtained with continuous moderate turbine agitation. Also, as can be seen, a continuous slow rake somewhat improves the filtration rate. In contrast, as can be seen, a substantial improvement in filtration rate was achieved by utilizing no agitation during aging and when intermittent agitation for 5 minutes per 8 hours was utilized a filtration rate indistinguishable from the no agitation filtration rate was obtained.
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A method of separating magnesium from wet process superphosphoric acid by filtration characterized by no or minimizing agitation during the crystallization of the magnesium in order to form readily filterable agglomerates of MgH 2 P 2 O 7 .
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a process for distillation of petroleum of fossil or synthetic origin by progressive separations, in which the feed preheated by heat exchange is prefractionated in successive steps in at least one column which operates at a pressure within the range of 1 to 5 atm. abs., as well as to an installation for the application of the process.
2. Description of the Prior Art
Processes are already known which utilize recovery heat for saving power and which carry out a preliminary and variable degree of separation of light fractions such as the light petroleum gases, the gasolines and kerosine prior to atmospheric distillation. However, the feed residue of these columns is necessarily reheated in one or a number of fuel furnaces prior to distillation within these columns.
SUMMARY OF THE INVENTION
The aim of the process in accordance with the present invention is to make improvements in the methods mentioned in the foregoing by carrying out a more progressive separation of petroleum fractions before and after atmospheric distillation in order to permit more effective utilization of heating by means of the recovery heat.
The basic concept of the invention lies in the discovery that, by carrying out a succession of progressive separations within a series of columns of relatively small volume, better utilization of the recovery heat is achieved by virtue of measured and judiciously distributed additions of heat.
Furthermore, progressive separations carried out under increasingly severe conditions of pressure and temperature permit the advantageous possibility of reducing the volume of effluent which, after reheating with a final addition of external heat and especially by means of a furnace, will be processed in a vacuum distillation column. The low power consumption thus achieved will be essentially due to effective utilization of recovery heat for carrying out successive separations and to the reduction in volume of effluent which is subjected to heating by an external heat source.
The process in accordance with the invention essentially consists in successively separating increasingly heavy petroleum cuts at the head of a plurality of columns of a first series of distillation columns each fed with a residue from the previous column and in collecting at the bottom of the last column of said series a so-called atmospheric residue which is then processed in a vacuum distillation zone in which provision is made for reheating of the feed in a furnace.
In a variant of the process, the atmospheric residue collected at the bottom of the last column of the first series is reheated in a furnace, then processed in a vacuum distillation column.
In another variant of the process, said residue is fed without any external addition of heat to a first vacuum distillation column, the residue of which is processed in a second vacuum distillation column after reheating in a furnace.
In accordance with a distinctive feature of the invention, each cut collected at the head of each column of the first series is fed individually to one column of a second series of columns, the distillates of which are standard petroleum products.
The process in accordance with the invention permits high operational flexibility according to established production criteria. Thus, instead of an arrangement such that one column of the second series corresponds to each column of the first series, a feasible practice now consists in feeding at least one column of the second series with volatile effluents from the two columns of the first series. A rearrangement of two columns of the second series will thus be achieved, for example either by mounting them one above the other so as to form a single column for fractionating gasolines with sidestream withdrawal or by regrouping the two columns which are placed downstream of the gasoline fractionating column and produce petroleum naphtha and kerosine.
It is also possible to add a supplementary column in each series of columns. Thus, should it be desired to enhance the production of intermediate gasoline, the gasoline fractionating column can be split into a second and third column of the second series. The residue of the second column consisting of intermediate gasoline is removed as a standard petroleum product or fed to the third column which is also fed with a cut collected at the head of a third column of the first series for separating the intermediate gasoline from the petroleum naphtha.
A supplementary column can be added as a function of other production criteria. For example, in the case of a requirement such as the production of a solvent between petroleum naphtha and kerosine, it would be possible to interpose a supplementary column which is located before the last column of the first series and feeds a supplementary column placed before the last column of the second series.
Similarly, the flexibility of the process results in the possibility of varying the feed circuit for the columns of the second series.
In accordance with one of the distinctive features of the process contemplated by the invention, a first column of the second series is a column for stabilization of gasolines, the volatile effluent of which is fed to a plant for fractionating light petroleum gases and the residue of which is combined with the emergent gasoline cut from the second column of the first series in order to feed a second column of the second series.
In accordance with another distinctive feature, a second column of the second series is a column for fractionating gasolines, the residue of which consists of a petroleum naphtha which is combined with the volatile fraction of a third column of the second series.
In accordance with yet another distinctive feature, the residue of the gasoline fractionating column feeds the next column of the same series.
In regard to addition of heat, the initial feed, the residues which flow between the columns of the first series and the effluents which flow between the columns of the second series are preferably preheated by transfer of sensible and latent heat released by other effluents without addition of heat by means such as a furnace.
Similarly, the addition of heat for reboiling of columns is advantageously carried out by heat transfer of the same nature. In particular, the addition of sensible heat takes partially place by heat exchange with a fraction of the residue issuing from the last vacuum distillation column and recycled to the feed inlet of the furnace.
In order to enhance the flexibility of the process even further and in order to introduce an addition of heat in the stream being processed, a judicious procedure which has become apparent and constitutes another distinctive feature of the invention consists in continuously recycling a fraction of the exit residue from the last vacuum distillation column into the feed stream of one or more of the atmospheric columns of the first series or of the first vacuum distillation column.
The invention is further directed to an installation for carrying out the process outlined in the foregoing. This installation is distinguished by the fact that the head outlets of four columns of the first series of columns are connected individually to the four columns of the second series of columns. The first of these four columns is a gasoline stabilization column, a head outlet of which is connected to an installation for fractionating light petroleum gases and a bottom outlet of which is connected to a second column which is a gasoline fractionating column, the head and bottom outlets of which are connected to gasoline storage tanks. The third column has the function of separating petroleum naphtha from kerosine and is connected to storage tanks. The fourth column is fed with the top fraction of the so-called atmospheric column which is the last of the first series of columns and is also connected to the storage tanks. Finally, the atmospheric column just mentioned, or last column of the first series, is a reflux column connected to a stripper which is in turn connected to a storage tank for so-called atmospheric gas-oil. Said atmospheric column is provided with a bottom outlet for the so-called atmospheric residue which is connected via a fuel-heated furnace to the feed inlet of a vacuum distillation column connected to storage tanks.
In an alternative embodiment, the so-called atmospheric column is connected via a bottom outlet to a first vacuum distillation column provided with sidestream withdrawal means and with a bottom outlet connected via the furnace to a second vacuum distillation column. Both vacuum distillation columns are connected via sidestream withdrawal means to tanks for storage of gas oil and distillates.
In another embodiment, a supplementary column is interposed between the second and the third column of the first series and its head outlet feeds a supplementary column which is interposed between the second and the third column of the second series and which may if necessary be fed by the bottom outlet of the second column of the second series. The head outlet of said supplementary column of the second series is connected to a tank for storage of intermediate gasoline.
In a further embodiment, a supplementary column is interposed between the third and the fourth column of the first series and its head outlet feeds a supplementary column which is interposed between the third and the fourth column of the second series and the head outlet of which is connected to a tank for storage of a solvent having a boiling point between that of petroleum naphtha and kerosine.
In again another embodiment, the second and the third column of the second series are columns superposed within a single gasoline fractionating tower, the bottom outlet of which feeds a fourth column of the second series, each column being connected to respective storage tanks.
In an alternative embodiment, the third and fourth columns of the second series are combined in a single column, the feed inlets of which are connected to the head outlets of the third and fourth columns of the first series.
In another embodiment, the inlet of the third column of the second series, which is a column for the separation of petroleum naphtha from kerosine, is connected to the bottom outlet of the preceding column in the same series and to the outlet of the third column of the first series.
BRIEF DESCRIPTION OF THE DRAWINGS
Other features of the invention will be more apparent to those skilled in the art upon consideration of the following description and accompanying drawings, wherein:
FIG. 1 is a general flow diagram in accordance with a particular embodiment;
FIGS. 2, 3, 4, 5 and 6 are general diagrams showing a number of alternative embodiments;
FIGS. 7, 8, 9 and 10 are partial detail diagrams of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The installation comprises two series of columns. The first series is composed of distillation columns which operate at atmospheric pressure or at a pressure higher than atmospheric and are designated by the references C01, C02, C03 and C10 provided with a stripper C11. These columns are each fed with a residue from the preceding column and their top fractions feed individually each one of the columns of the second series of distillation columns C07, C04, C05 and C06. The base of the last column C10, or so-called atmospheric column, feeds with atmospheric residue a first vacuum distillation column C12. The residue from this first column is preheated in a single fuel furnace and introduced into a second vacuum distillation column C13.
The columns of the first series are plate-type distillation columns for the separation of top fractions and bottom fractions. In regard to temperature and pressure values, the operating conditions of these plate columns are predetermined with a view to ensuring that the volatile fractions released become progressively heavier. Thus, preheating of the residues fed to the columns and carried out by exchange of sensible and latent heat with other effluents has the effect of heating said residues to increasing temperatures in the order in which the columns are placed. The volatile fraction of column C01 composed of all the light petroleum gases and part of the gasolines is fed to column C07 of the second series which is a column for stabilization of gasolines, the volatile fraction of which feeds a plant for fractionating light petroleum gases. The volatile fraction of column C02 is combined with the residue of column C07 and feeds gasoline alone to column C04 which is a gasoline fractionating column, the head effluent of which is a light gasoline and the residue of which is a petroleum naphtha.
The volatile fraction of column C03 composed of a remaining quantity of kerosine is fed to column C05 which extracts petroleum naphtha from this latter as a volatile fraction and kerosine as a residue. The last column C10 of the first series is a reflux atmospheric column, the bottom of which is stripped with steam. A stripper C11 is connected to the top section of the column. The volatile fraction of column C10 feeds column C06 and an effluent containing gasoline, kerosine and water. The residue of column C06 is kerosine which combines with the residue of column C05 for subsequent storage. After separation of water, the volatile fraction constitutes the remainder of the petroleum naphtha which is transferred to storage.
The stripper C11 of column C10 serves to remove volatile fractions from the light atmospheric gas-oil prior to transfer to storage. The atmospheric residue which is steam-stripped at the bottom of column C10 is introduced into a first vacuum distillation column C12 in which three volatile fractions are separated by expansion and are withdrawn as sidestreams at different column levels: heavy gas-oil, vacuum gas-oil and a vacuum distillate as well as a residue. The residue from column C12 is heated in a fuel furnace, then introduced into a second vacuum distillation column C13 which separates a number of vacuum distillate cuts as well as a vacuum residue.
In the example of application which now follows with reference to the detail diagram shown in FIGS. 7 to 10, a feedstock of Arabian crude oil is processed in a plant of the type described earlier.
A charge of 771.6 t/h at 15° C. (stream F1) is pumped from storage by means of the pump P01 and preheated under pressure at 140° C. by heat transfer by means of the following heat-exchangers : E01 (condenser of column C04), E02 (circulating reflux F28 of the vacuum distillate), E03 (circulating reflux F20 of atmospheric gas-oil), E04 (condenser of column C01), E05 (condenser of column C06), E06 (circulating reflux of atmospheric gas-oil), E07 (atmospheric gas-oil F14), E08 (gas-oil F22 under vacuum), E09 (circulating reflux of vacuum distillate), E10 (condenser of column C05), E11 (distillate F16 of column C10), E12 (kerosine F45), E13 (distillate F16 of column C10) and E14 (atmospheric gas-oil}. The crude is desalted in a two-stage desalting unit B08, B09, then heated under pressure at 157° C. (F2) in the heat-exchangers E15 (low-pressure steam), E16 (vacuum distillates F32) and E17 (atmospheric gas-oil) and is fed to the column C01 at 2 bar abs.
The exit steam flow F3 from column C01 is partially condensed at 94° C. within the heat-exchanger E04.
The reflux is pumped from the reflux drum B01 by means of the pump P04 and returned to the head of column C01.
The steam distillate stream F4 composed of light petroleum gases and gasoline and flowing out of the reflux drum is passed to a so-called stabilizing column C07 which will be described hereinafter.
The stream F5 from the bottom of column C01 is recirculated by the pump P03 and reheated to 196° C. by means of the following heat-exchangers : E18 (vacuum distillate F23) E19 (condenser of column C10), E20 (circulating reflux F19 of gas-oil under vacuum), E21 (circulating reflux F27 of vacuum distillate), E22 (distillate F10 of column C03), E23 (circulating reflux of gas-oil under vacuum), E24 (circulating reflux F18 of vacuum distillate). The generated steam F6 is separated from the liquid in the drum B07, then returns into column C01. The liquid F7 is recirculated by the pump P05, then heated under pressure to 247° C. by means of the following heat-exchangers E25 (circulating reflux F27 of vacuum distillate), E26 (circulating reflux of gas-oil under vacuum), E27 (circulating reflux of vacuum distillate), E28 (condenser of column C03), E29 (vacuum distillate F29), E30 (vacuum residue F33), E31 (circulating reflux F13 with atmospheric gas-oil), E32 (vacuum residue), E33 (circulating reflux with atmospheric gas-oil), E34 (circulating reflux F17 for feeding column C12), E35 (circulating reflux of vacuum distillate) and E36 (circulating reflux with atmospheric gas-oil). This stream is fed to column C02 at 1.95 bars abs. This column produces a stream F8 of steam distillate at 141° C. consisting of a gasoline cut. The reflux from column C02 takes place via the heat-exchanger E52 (very-low-pressure steam generator), the drum B02 and the pump P07.
The stream F9 from the bottom of column C02 is recirculated by the pump P06, then heated under pressure to 296° C. by means of the following heat-exchangers: E37 (vacuum residue), E38 (vacuum residue), E39 (circulating reflux F26 and vacuum distillate), E40 (vacuum residue) and E41 (circulating reflux F25 of column C13). The stream which has thus been heated is fed to column C03 at 2.5 bar abs. This column produces a steam distillate F10 at 222° C., this distillate being composed of petroleum naphtha and kerosine. The reflux from said column C03 takes place via the heat-exchanger E28, the drum B03 and the pump P09. The stream F11 from the bottom of the column is recirculated by the pump P08, heated to 320° C. within the heat-exchanger E42 (vacuum residue), then mixed with 100 t/h of vacuum residue F12 at 380° C. in order to feed column C1O at 2.3 bar abs. The bottom of said column is stripped with 7.5 t/h of low-pressure steam. This column is provided with a circulating reflux with withdrawal of gas-oil F13 in order to condense the internal reflux which is necessary for good performance of the column. A side stripper C11 makes it possible to obtain 59 t/h of atmospheric gas-oil F14 consisting of a cut of petroleum naphtha, of kerosine and of steam. The heat-exchanger E19, the drum B10 and the pump P09 effect the reflux of the column. This reflux produces fractionation between the kerosine and gas-oil cuts.
The gas-oil thus produced is cooled to 45° C. within the heat-exchangers E17, E14, E07 and E59 (coolant water).
The residue F15 of the column or so-called atmospheric residue is fed to column C12 at 0.1 bar abs. The bottom of this column is stripped with 8 t/h of very-low-pressure steam. The column is provided with four circulating refluxes effected respectively by the following equipment units, starting from the base of the column:
pump P21 and heat-exchanger E34 : feed circulating-reflux F17
pump P22 and heat-exchanger E24 : circulating reflux F18 of vacuum distillate
pump P23 and heat-exchangers E26, E 23, E20 : circulating reflux of gas-oil under vacuum F19
pump P24 and heat-exchangers E06, E03 : circulating reflux of atmospheric gas-oil F20.
This column produces 80 t/h of atmospheric gas-oil F21 which is cooled to 45° C. by the heat-exchanger E60 (coolant water), 38 t/h of gas-oil under vacuum F22 which is cooled to 45° C. within the heat-exchangers E08, E55 (air preheater of the furnace) and 24 t/h of vacuum distillate F23, the available heat of which is recovered up to 160° C. within the heat-exchanger E18.
The vacuum of the column is produced by a precondenser and a group of ejector condensers which is common with the column C13. The process water is recirculated by the pump P25 from the drum B11 to a water-treatment plant.
The residue of said column F24 which is recirculated by the pump P20 is heated to 400° C. within a furnace F01 and diluted with 13 t/h of low-pressure steam and is then fed to column C13 which operates at 0.1 bar abs.
The column C13 is provided with four circulating refluxes which are effected respectively by the following equipment units starting from the base of the column :
pump P27 and heat-exchanger E41 : feed circulating-reflux F25
pump P28 and heat-exchanger E39 : circulating reflux F26 of vacuum distillate
pump P29 and heat-exchangers E35, E47 (reboiler of column C06), E25, E27, E21 (circulating reflux F27 of vacuum distillate)
pump P30 and heat-exchangers E09 and E02 : circulating reflux F28 of vacuum distillate.
The column C13 produces three cuts of vacuum distillate respectively, starting from the base of the column : vacuum distillate No 4, F29 ; No 3, F30 ; No 2, F31, namely a total stream flow F32 of 152 t/h.
Recovery of heat up to 160° C. contained in these streams takes place within the heat-exchanger E16, vacuum distillate No 4 having previously been cooled within the heat-exchanger E29. The bottom of the column is stripped with 9 t/h of very-low-pressure steam. The vacuum residue produced at the bottom of the tower is recirculated by the pump P26 and part of this residue under hot vacuum is recycled upstream of the column C10. The vacuum residue is successively cooled to 230° C. within the heat-exchangers E42, E40, E38, E46 (reheating of column C05), E37, E32 and E30. After the heat-exchanger E42, part of this residue is recycled to the bottom of the tower in order to adjust the temperature of the stream F34.
A vacuum is produced within said column by means of a precondenser and an ejector-condenser system which is common with column C12.
The steam distillate (F4) which passes out of the column C01 is cooled to 40° C. within the heat-exchanger E61 (coolant water). The liquid and vapor phases thus obtained are separated within the drum B12. The vapor phase F35 is heated to 60° C. within the heat-exchanger E50 (petroleum naphtha) before being compressed to 4 bar abs. by means of the compressor K01 in order to feed column C07. The liquid phase is recirculated by the pump P31, heated to 80° C. within the heat-exchanger E51 (petroleum naphtha) before being fed to the column C07 (stream F36).
The column C07 is reboiled by means of the heatexchangers E43 (kerosine) and E44 (low-pressure steam). Top-of-column condensation is produced by a cooling cycle composed of the drum B13, heat-exchangers E62 (coolant water), compressors K03 and the condenser E53. Condensation of part of the top-of-column stream takes place within the drum B14. The pump P32 effects the reflux of column C07. A flow rate of 15 t/h of light petroleum gases is accordingly produced. The residue F37 from column C07 is fed directly to column C04 by expansion at 1.7 bar abs. This column is also fed with the steam distillate F8 from column C02.
Reboiling of column C04 is carried out by the heat-exchanger E45. The steam flow from the top of the column is entirely condensed within the heat-exchanger E01, then collected within the drum B04. The pump P04 effects the reflux and transport of the 37 t/h of light gasoline F38 produced at the top of the column. This gasoline is cooled to 40° C. within the heat-exchanger E56 (coolant water). The residue F39 obtained at the bottom of the column and recirculated by the pump P10 consists of 40 t/h of a petroleum naphtha cut which, after having been mixed with the petroleum naphtha produced at the head of the columns C05, F40, and C06, F41, is cooled to 40° C. within the heat-exchangers E51, E50, E57 (coolant water).
The distillate F10 which passes out of column C03 and is cooled to 195° C. and 2 bar abs. within the heat-exchanger E22 is fed to column C05 which produces a liquid distillate of 23 t/h of petroleum naphtha F40 and a kerosine residue F42 of 10 t/h.
Reboiling of column C05 is carried out by the heat-exchanger E46. Condensation of the reflux and of the distillate takes place within the heat-exchanger E10 and the drum B05. The pump P05 effects the reflux at the top of the column and transfers the petroleum naphtha. The kerosine produced at the bottom is recirculated by the pump P12 and cooled to 40° C., after mixing with the 45 t/h of kerosine F43 produced at the bottom of the column C06, within the following heat-exchangers : E43, E12, E48 and E49 (addition of heat to the light gas treatment section), E58 (coolant water).
The steam distillate F16 which passes out of column C10 is cooled to 125° C. and 1.7 bar abs. within the heat-exchangers E13, E11 and is fed to column C06. This column produces at the top a liquid distillate of 13 t/h of a petroleum naphtha cut F44 and produces at the bottom 48 t/h of kerosine F43. Total condensation of the flow from the top of the column takes place within the heat-exchanger E05. The drum B06 serves to separate the hydrocarbon and water phases. The pump P15 effects the reflux and transfer of the petroleum naphtha. The process water is passed by the pump P16 to the water treatment. Reboiling of column C06 is carried out by means of the heat-exchanger E47. The pump P14 serves to transfer the kerosine produced within the column.
The process and installation in accordance with the invention can be adapted to a wide range of variants, a few of which are illustrated in the diagrams of FIGS. 2 to 6.
It is thus possible to dispense with the first vacuum distillation column C12 (as shown in FIG. 2) and to pass the atmospheric residue from the atmospheric column C10 through the furnace into the second vacuum distillation column C13, the effluents of which contain both the heavy gas-oils and the vacuum gas-oils as well as the distillates.
In accordance with another variant shown in FIG. 3, columns C04 and C05 are combined into a single tower for fractionating gasolines and kerosine with sidestream withdrawl, said tower being fed with the effluents from columns C02 and C03 of the first series of columns.
In yet another variant shown in FIG. 4, the last two columns C05 and C06 of the second series have been combined into a single column supplied with the volatile effluents from columns C03 and C10.
In a further varient shown in FIG. 5, a supplimentary column C04' and a supplimentary column C02' have been interposed respectively in the second and the first series of columns. This diagram is particularly applicable when it is desired to enhance the production of intermediate gasoline.
Column C04' is fed with the residue from column C04 and with the volatile effluents from column C02'.
In the variant illustrated in FIG. 6, the column C05 which separates petroleum naphtha from kerosine is fed with the volatile effluents from column C03 and with the residue from column C04.
Other variants could be applied to the process and to the installation in accordance with the invention without thereby departing from its scope, in particular as a function of pre-established production criteria.
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The process consists in successively separating increasingly heavy petroleum cuts at the head of a plurality of columns CO1, CO2, CO3 and Cl0 of a first series of columns which feed individually each column of the second series. The column CO7 is a gasoline stabilizing column which feeds an installation for fractionating light petroleum gases. The column CO4 is a gasoline fractionating column. The columns CO5 and CO6 are columns for separating petroleum naphthas from kerosine. The atmospheric residue collected at the bottom of the column Cl0 is processed in the vacuum distillation column Cl2 and the residue from this column is processed in the second vacuum distillation column Cl3 after reheating in a furnace.
By carrying out a succession of progressive separations performed in a series of columns of small volume, more efficient utilization of the recovery heat is achieved.
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RELATED APPLICATION
[0001] This application claims the benefit of U.S. Provisional Application No. 60/812,661, filed Jun. 9, 2006, which is incorporated herein by reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] Embodiments of the present invention generally relate to the treatment of carpal tunnel syndrome, and more particularly to a system and method for simultaneously applying a plurality of therapeutic modalities to treat carpal tunnel syndrome.
[0003] Carpal Tunnel Syndrome affects a wide demographic of the population. Occupational hazards such as typing in offices, performing mechanical operations repetitively, and carrying of heavy loads create repetitive stress injuries in the joint structures of the wrist and hand. These stresses irritate and inflame the carpal ligaments (both volar and transverse), as well as tendons and tissues between the ulna and radius bones of the forearm and the metacarpals. This inflammation leads to edema and swelling, which puts pressure on neural pathways (median nerve and to a lesser extent the ulnar nerve), as well as blood flow structures (radial artery and to a lesser extent the ulnar artery). The condition is painful, causes inflamed regions and pockets of fluid that decrease mobility, and diminishes nerve signal conduction resulting in a loss of control of the hand and finger structures. Carpal Tunnel Syndrome is progressive. As irritation, edema, and inflammation increase, numbness, pain, tingling sensations in the hand and digits and general swelling increase. The condition can progress such that neural scarring occurs, further decreasing nerve conduction.
[0004] Once the condition has produced sufficient neural scarring, invasive procedures are utilized to treat the patient. These procedures include releasing (severing) the transverse and possibly volar carpal ligaments, and additionally in some cases scraping away scar tissue.
[0005] Patients who seek intervention prior to the need for invasive procedures may receive manually applied physical therapy. These therapies are designed to non-invasively increase the mobility of the nerve structures of the carpal tunnel region. They are also designed to move fluids through the region, decreasing edema and pressure. Light therapy, including light sources such as lamps, light emitting diodes (LEDs), and “cold” lasers, may be applied to specific points for definite periods of time in an effort to increase local healing functions and reduce inflammation. In some cases, a carpal strap is applied about the carpal tunnel region between the metacarpals and the ulna and radius bones of the forearm. This strap is tightened such that pressures applied perpendicular to the flat of the hand press the carpal bones (including the harnate, capitate, trapeziod, trapezium, scaphoid, and lunate). This action deepens the carpal tunnel in an effort to increase the carpal tunnel space and relieve pressure on the median nerve. This action also decreases the stress on the transverse and volar ligaments. Patients are typically instructed to wear a wrist splint, which immobilizes the wrist, reducing further irritation through movement of the structures during periods throughout the day. A patient's daily activities may be assessed for causes of the irritation. More ergonomic methods may be suggested for activities which incite and irritate the carpal tunnel region. Finally, TENS units may be applied and additionally issued to patients for the reduction of pain and ability to increase cellular functions related to healing.
[0006] Exercises, both those with and without the assistance of a healthcare provider, are dependent upon technique and may vary from application to application. As well, exercises assisted by a healthcare provider require one-on-one time which is increasingly difficult to schedule as the number of patients exhibiting symptoms of carpal tunnel Syndrome increases.
[0007] Light therapy via cold laser therapy requires knowledgeable application by a healthcare professional and is point dependent—again placement of the laser can vary from application to application. Cold laser therapy covers only a small region of the carpal tunnel, resulting in the need for repeated applications. Additionally the wavelength of the laser is finite by the nature of the technology—it has been demonstrated that wavelengths between 790 nm and 870 nm are preferable for the treatment of inflammation and increased cellular function. Cold laser instruments are also expensive and require safety goggles to protect patient and healthcare provider vision. Light Therapy from lamps and LEDs can be applied about the carpal region. Flexible light pads containing lamps and LEDs provide heat and general light. In both cold laser and non-laser illumination, the carpal bones absorb and reflect a significant amount of light. As the bones block the underside of the carpal tunnel, light is typically directed around and about these structures—these methods limit the exposure of affected structures to the benefits of light therapy. As before, the one-on-one time required between patient and physician is increasingly difficult to schedule, and often a compromise between manual manipulation for mobility and some form of light therapy is required.
[0008] Carpal straps and wrist splints are affective for short periods of time and are dependent upon application. Often these devices are applied by unskilled patients, thereby limiting the effectiveness of the device.
SUMMARY OF THE INVENTION
[0009] Certain embodiments of the present invention provide a combination of effective modalities (Light Therapy and Electrical Stimulation) simultaneously to achieve a higher degree of effectiveness relative to the time spent in the healthcare provider's facility. Further, a device that may apply these modalities in an automatic fashion, requiring limited setup by a healthcare provider, increases the number of patients who may be successfully treated. A device that automates these modalities may also manipulate the carpal tunnel region simultaneously to circulate fluids and open the carpal spaces. The automated manipulation can be designed such that the bone structures of the carpal tunnel are separated, allowing the application of light therapy to penetrate deeper beyond and around the bones that would otherwise block their delivery.
[0010] Such a device would expedite the healing process of the patient and provide an opportunity for healthcare providers to treat more patients. The majority of a healthcare provider's time could be spent performing and instructing on stretches and exercises designed to increase mobility and move edema through the affected regions, counseling the patient on the use of passive immobilization devices outside of the healthcare provider's office, and assessing and counseling patients on more ergonomic methods of utilizing the hands and wrist.
[0011] Certain embodiments of the present invention include a system for capturing and positioning the wrist and hand of a patient for the application of a plurality of therapeutic modalities. The system includes a conforming, ergonomic portion above and below the hand and wrist that positions the structures for optimal delivery of therapeutic modalities. The lower portion may remain stationary while the upper portion is automatically lowered upon the hand and wrist. Tension measuring device(s) detect pressures exerted upon the hand and wrist so as to optimize capture of the structures while limiting the possibility of cutting off circulation and placing excessive pressures on the carpal tunnel space. The hand may be placed into this structure flat, parallel to the ground.
[0012] Certain embodiments of the present invention provide a system and method of placement of therapy devices containing both light therapy and electrical stimulation components. The placement of the therapy devices are optimized such that light therapy is fixedly directed to the entirety of the carpal tunnel region extending from the ends of the ulna and radius forearm bones to just above the beginning of the metacarpals. Electrical stimulation is fixedly placed such that bipolar interferential (two pad) electrical stimulation is applied above, about, and below the carpal tunnel region. Additionally, switching mechanisms allow for electrical pad designations that convert the pain blocking bipolar interferential therapies to change to a crosswise pattern that allows quadripolar interferential therapy. The electrodes are positioned such that the epicenter of the interference pattern is located central to the carpal tunnel. This switching mechanism allows for on-the-fly adjustments for optimal therapeutic benefit.
[0013] Certain embodiments of the present invention include an automated rotation of the hand and wrist once placed and secured between the upper and lower portions of the capturing device previously described. The hand and wrist are rotated 90° outward, palm facing towards the body, perpendicular to the floor. This action places the muscles and tendons in a natural state more suited to stimulation and the application of decompressive tensile forces. The hand and wrist capturing devices and light therapy and electrical stimulation apparatus is further automated to apply decompressive tensile forces inline with the forearm, wrist and hand. These forces extend and decompress the carpal bones, allowing light therapy to penetrate from all sides of the wrist into the carpal tunnel. Decompressive tensile forces are applied logarithmically and are alternated between upper and lower tensile force plateaus. The alternation of the forces produces a pumping motion that stimulates movement of fluids through the carpal tunnel. Fluids influenced include blood supply, nourishing the wrist and hand, as well as those associated with edema, moving them through and away from the carpal tunnel.
[0014] Embodiments of the invention described above are useful in the treatment of Carpal Tunnel Syndrome (CTS) as it may arise again after invasive procedures have occurred. The system is also capable of routine application as a preventative measure for those patients who have undergone invasive procedures.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 illustrates the wrist and hand bone structure.
[0016] FIG. 2 illustrates the ligament, nerve, and artery structures of the wrist and hand associated with Carpal Tunnel Syndrome.
[0017] FIG. 3 illustrates a lower portion of a therapy housing used to contain the wrist and hand according to one embodiment of the present invention.
[0018] FIG. 4 illustrates a therapeutic system for automatically compressing a wrist and hand between the upper portion and the lower portion of the form structure according to one embodiment of the present invention.
[0019] FIG. 5 illustrates a proximal therapeutic device that is used to supply light therapy and electrical stimulation simultaneously to the hand and wrist according to one embodiment of the present invention.
[0020] FIG. 6 illustrates a distal therapeutic device that is used to supply light therapy and electrical stimulation simultaneously to the hand and wrist according to one embodiment of the present invention.
[0021] FIG. 7 illustrates a system for aligning the light and electrical stimulation of a proximal and distal therapeutic device within the lower portion of a therapy housing according to one embodiment of the present invention.
[0022] FIG. 8 illustrates a wrist and hand positioned in the lower portion of a therapy housing according to one embodiment of the present invention.
[0023] FIG. 9 illustrates a wrist and hand compressed between the upper and lower portions of a therapy housing according to one embodiment of the present invention.
[0024] FIG. 10 illustrates a rotated and compressed wrist and hand and a secured upper arm during use of a therapeutic system in accordance with one embodiment of the present invention.
[0025] FIG. 11 is a top plan view of a wrist and hand positioned between the proximal and distal therapeutic devices as they may be positioned within the therapy housing (not shown) according to one embodiment of the present invention.
[0026] FIG. 12 is a top plan view of a wrist and hand undergoing Quadripolar Interferential stimulation while positioned between proximal and distal therapeutic devices according to one embodiment of the present invention.
[0027] FIG. 13 is a top plan view of an upper and lower proximal and distal therapeutic devices positioned about a patient's wrist and hand that is undergoing Medium Frequency or Bipolar Interferential stimulation of the carpal tunnel region according to one embodiment of the present invention.
[0028] The foregoing summary, as well as the following detailed description of certain embodiments of the present invention, will be better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, there is shown in the drawings, certain embodiments. It should be understood, however, that the present invention is not limited to the arrangements and instrumentalities shown in the attached drawings.
DETAILED DESCRIPTION OF THE INVENTION
[0029] FIG. 1 illustrates the wrist and hand bone structure 100 . The distal heads of the ulna forearm bone 105 and radius forearm bone 110 are shown crossing into the carpal tunnel region 155 of treatment. Although the focus of the light therapy and electrical stimulation of the present invention may be the carpal tunnel region 155 , in some embodiments of the present invention the light therapy and electrical simulation may also cover areas distal and/or proximal to the carpal tunnel region 155 . Distal to the carpal tunnel region 155 are the metacarpal bones 115 . The proximal metacarpal bones 115 are shown included in the carpal tunnel region 155 . The various bones of the wrist are all contained within the carpal tunnel region 155 , and include the lunate 120 , triquetral 125 , capitate 130 , harnate 135 , scaphoid 140 , trapezoid 145 , and trapezium 150 . The wrist bones may form the bottom and partial sides of the carpal tunnel region 155 itself. The decompressive tensile forces of the present invention seek to extend the spaces between these bones such that light therapy from a plurality of sources and types, including, but not limited to, laser, LED, and lamp, may penetrate between and into the bottom of the carpal tunnel region 155 .
[0030] FIG. 2 illustrates the ligament, nerve, and artery structures of the wrist and hand associated with Carpal Tunnel Syndrome (CTS). The two major carpal tunnel ligaments 270 associated with CTS are the volar carpal ligament 210 and the transverse carpal ligament 220 . The volar carpal ligament 210 and the transverse carpal ligament 220 may be relieved by the compressive forces of a carpal strap by exerting pressures on either side of the carpal tunnel region. Where a patient's condition indicates the need, the volar and transverse carpal ligaments 210 , 220 may be cut or “released” via invasive surgeries.
[0031] Extending through and about the carpal tunnel region 155 are the nerves, such as the median nerve 230 and the ulnar nerve 250 , along with arteries, such as the radial artery 240 and the ulnar artery 260 , that may be associated with CTS. The median nerve 230 may run directly through the center of the carpal tunnel region and may be affected by irritation and edema associated with CTS. With the infliction of CTS, the median nerve 230 conduction velocity may be gradually diminished, which eventually may lead to neural scarring that may require invasive scraping and removal. The radial artery 240 also may run through and about the carpal tunnel region. Through irritation and edema within the carpal tunnel region, the radial artery 240 may become compressed, thereby becoming less able to deliver blood to the structures of the wrist and hand.
[0032] Secondary structures affected by CTS may include the ulnar nerve 250 and ulnar artery 260 . Both the ulnar nerve 250 and ulnar artery 260 run through and about the carpal tunnel region. As discussed below, embodiments of the present invention may be configured to relieve irritation and edema related pressure on the median nerve 230 , radial artery 240 , ulnar nerve 250 and ulnar artery 260 by directing light therapy, electrical stimulation, and decompressive tensile force simultaneously at and about the carpal tunnel region.
[0033] FIG. 3 illustrates a lower portion 300 of a therapy housing used to contain the wrist and hand according to one embodiment of the present invention. The therapy housing may include both a lower portion 300 , as shown in FIG. 3 , and an upper portion (not shown). The upper portion may or may not have a configuration similar or at least generally identical to that of the lower portion 300 . Further, the lower portion 300 and the upper portion may be configured so that, when properly oriented and used in conjunction with each other, at least a portion of a patient's hand and/or wrist is enclosed by the therapy housing. Additionally, the therapy housing may be configured so as to accommodate a variety of different wrist and hand morphologies. When the upper portion and lower portion 300 of the therapy housing are in position for the therapeutic treatment of CTS, the therapy housing may also allow decompressive tensile forces to be comfortably applied to the hand and/or wrist.
[0034] In one embodiment of the present invention, the lower portion 300 of the therapy housing may be constructed with conforming foam that is built upon a rigid platform. The conforming foam may assist in attempting to evenly and comfortably distribute pressures that may be exerted on the hand and wrist when the hand and wrist are at least partially enclosed by upper portion and lower portion 300 of the therapy housing. In use, a patient's wrist may be laid into a wrist channel 310 on the lower portion 300 of the therapy housing. Wrist supports 350 may be located at either side of the wrist channel 310 so as to assist in properly positioning the hand and wrist of a patient at the desired location. The wrist supports 350 may also be configured to allow for the repeated placement of different patients' wrists in the same general location in the therapy housing. In one embodiment, the sizing and placement of the wrist supports 350 may also allow the lower portion 300 to “grab” the hand distal and at the heads of the ulna and radius forearm bones.
[0035] In one embodiment of the present invention, the wrist supports 350 may be extruded foam blocks. By constructing the wrist channel 310 primarily of conforming foam, the wrist channel 310 may be able to expand to accommodate larger wrist structures, which may thereby assist in allowing the placement of wrist and hand of many different patients in the same general location within the therapy housing.
[0036] In accordance with one embodiment of the current invention, the wrist supports 350 may extend several inches back from the heads of the ulna and radius forearm bones 105 , 110 , which may accommodate and seat the wrist sufficiently for therapy.
[0037] The lower portion 300 of the therapy housing may also include a carpal tunnel area 360 . The carpal tunnel area 360 may be designed to exert as little compressive force from the therapy housing as possible. Therefore, according to one embodiment of the present invention, the tunnel area may be a recessed surface that is configured so as to prevent any further irritation of the patient's CTS.
[0038] The lower portion 300 of the therapy housing may also extend beyond the wrist supports 350 sufficiently far so as to seat the patient's hand. The patient's hand may lie on a hand support region 320 that may be a relatively flat area or an at least partially contoured area. The hand region 320 may include foam that may assist in at least partially distributing compressive forces exerted upon the hand by the upper portion and/or lower portion of the therapy housing as evenly and comfortably as possible.
[0039] FIG. 4 illustrates a therapeutic system 400 for automatically compressing a wrist and hand between the upper portion 410 and the lower portion 300 of the therapy housing 900 according to one embodiment of the present invention. The therapeutic system 400 may include a controller 485 which receives commands from a computer that allows healthcare providers to set individual parameters for the treatment of different patients. The controller 485 may automate the lowering of the upper portion 410 of the therapy housing 900 upon the patient's hand. For example, the upper portion 410 may be lowered via a mechanical scissors apparatus 415 secured to the top of a fixed mechanical framework 405 and to the bottom of the upper portion 410 of the therapy housing 900 . The mechanical scissors apparatus 415 may be extended and contracted, exacting a lowering and raising of the upper portion 410 , by a rotational motor, for example a stepper motor 420 . Further, the stepper motor 420 may be operated by a controller 485 . In such an embodiment, the stepper motor 420 may include a threaded motor shaft screw that is rotated, thereby causing the centers of the mechanical scissors apparatus 415 to be forced outward, which results in the upper portion 410 of the therapy housing 900 to be extended downwards toward the lower portion 300 of the therapy housing 900 . The upper portion 410 of the therapy housing 900 may ride along rails 425 , which may smoothly deliver the upper portion 410 of the therapy housing 900 upward and downward, relative to the mechanical framework 405 .
[0040] In accordance with the embodiment of the present invention illustrated in FIG. 4 , in operation, a patient's wrist and hand may be seated on or against the lower portion 300 of the therapy housing 900 while the upper portion 410 may be at least partially retracted. Once the patient's wrist and hand are seated in the lower portion 300 , the upper portion 410 of the therapy housing 900 may be lowered onto at least a portion of the patient's hand and/or wrist by the rotation of the stepper motor 420 threaded shaft screw and resulting extension of the mechanical scissors apparatus 415 , as described above. A tension measuring device 435 , for example a load cell or load button, may be located underneath the lower portion 300 of the therapy housing 900 , and may provide compressive force feedback to the controller 485 . Based on feedback from the tension measuring device 435 , the controller 485 may continuously adjust the compression exerted on the wrist and hand by controlling the position of the upper portion 410 of the therapy housing 900 through the activation of the stepper motor 420 .
[0041] In one embodiment of the present invention, once the wrist and hand are compressed between the upper and lower portions 410 , 300 of the therapy housing 900 , the therapy housing 900 (and the hand inserted therein) may be rotated, for example by rotation assembly that may rotate the therapy housing approximately 90 degrees outward. Rotational adjustment of the location of hand and wrist may allow for the wrist and hand of the patient to be placed at an optimal position for treatment. Any number of mechanical devices and connections may be utilized by the rotation assembly to rotate the therapy housing. For example, the rotation assembly may be comprised of chains and sprockets, belts and pulleys, or the direct coupling of a motor to the therapy housing, among others. In the embodiment illustrated in FIG. 4 , this rotational adjustment may be achieved by rigidly securing the mechanical framework 405 to a large gear 440 . The large gear 440 is rotationally fixed to one side of a roller bearing, which is rigidly fixed to an intermediate frame 445 . The large gear 440 may be rotated in either direction by a smaller gear 450 , which may be connected to the output shaft of a gearbox 455 . The large gear 440 , small gear 450 , and gearbox 455 may provide sufficient mechanical advantage such that a small rotation motor 460 may be capable of smoothly rotating and holding in place the mechanical framework 405 of the wrist and hand capturing therapy housing 900 . Suitable rotational motors 460 include, but are not limited to, a servo motor, which may receive commands from a servo amplifier located within the controller 485 .
[0042] The large gear 440 may also be connected to a device that accurately records position, such as, but not limited to, a potentiometer, resolver, encoder, or absolute position sensor. The rotational sensing device may also be an absolute position sensor, which, upon device power up, relays feedback to the controller 485 of the exact position of the large gear 440 without the need to find a homing sensor and/or limit sensors. Limit sensors and mechanical stops may be positioned such that the rotation cannot exceed 90 degrees in either direction. Additionally, if the device is to only treat either the left or right wrist and hand, limit sensors and mechanical stops can be positioned to limit rotation to 90 degrees in a specific direction.
[0043] The frame 455 of the present embodiment supporting the rotation and compression devices described above may be secured to two hardened steel shafts 465 via pillow blocks located beneath it 455 figure. This may allow the frame 455 to slide linearly. Additionally a threaded mechanical screw 470 running between the steel shafts 465 may be held suspended between two lower support blocks 472 . The threaded mechanical screw 470 may be free to rotate, via bearings within the support blocks 472 . These support blocks 472 may also rigidly hold the steel shafting 465 .
[0044] In the embodiment illustrated in FIG. 4 , a small rotational motor 480 is coupled to a gearbox 475 , which is coupled to the threaded mechanical screw 470 . The small rotational motor 480 is operated by the controller 485 . The small rotational motor 480 may be a servo motor, and may be controlled via a servo amplifier located within the controller 485 . The threaded mechanical shaft 470 may be coupled to the frame 455 via an external linear nut that is rigidly fixed underneath the frame 455 . As the small rotational motor 480 rotates the threaded mechanical shaft 470 , the frame 455 is moved linearly forwards and backwards.
[0045] In one embodiment of the present invention in FIG. 4 , the upper arm of the patient may be held in a fixed position at the level of the side of the body by an upper arm restraint, such as that shown in FIG. 10 . The captured and rotated wrist and hand are moved linearly away from and back towards the elbow by the actions of the small rotational motor. As this cyclic action occurs, the bone structures of the wrist and hand are extended and retracted, affecting a cyclic unloading of said bone structions. This action decompresses the bone structures of the hand and wrist. The decompressive tensile forces described above are measured by a tension measuring device that may located within an upper arm restraining device that retains the position of the upper arm. The tensile force feedback of the upper arm restraining device may be fed back to the controller 485 , which may adjust and keep safe decompressive tensile force levels.
[0046] Dual light therapy and electrical stimulation devices may be located within the upper portion 410 and/or the lower portion 300 of the therapy housing 900 , which may apply simultaneous therapy to the hand and wrist. During periods of decompressive tensile force application, the controller 485 may power the light therapy devices such that light therapy is applied from above and/or below the wrist and hand. The controller 485 may also control the continuous application of electrical stimulation therapy. The decompressive tensile force may also be configured to cause a pumping action on the hand and/or wrist as it is cycled logarithmically between periods of maximum and minimum tension, thereby assisting in the movement of fluid through and about the wrist, reducing edema. Decompressive tensile forces may also promote the improvement of mobility of structures located within the carpal tunnel.
[0047] FIG. 5 illustrates a proximal therapeutic device 500 that is used to supply light therapy and electrical stimulation simultaneously to the hand and wrist according to one embodiment of the present invention. The proximal therapeutic device 500 shown may be housed in a single structure 540 . Further, the proximal therapeutic device 500 may be made of a solid, optically transparent material, for example ABS plastic, that is biologically safe for application to the skin. The proximal therapeutic device 500 may include a plurality of light therapy sources 520 , such as, but are not limited to, lasers, LEDs and lamps, or a combination thereof. The light therapy sources 520 may be arranged such that illumination is permitted to extend upward or downward and into the patient's carpal tunnel region. In one embodiment of the present invention, at least a portion of the light therapy sources may be positioned within the therapy housing. In such an embodiment, the light therapy sources 520 may be located nearer to the wrist, such as about and beyond the proximal heads of the metacarpals of the hand.
[0048] The proximal therapeutic device 500 shown in FIG. 5 may also include at least one electrode 510 . The electrode 510 may be made of a biologically safe material, including, but not limited to, medical-grade metals, such as stainless steel, and silicon-rubber doped with such agents as carbon-black, silver, and gold, among others. Further, in one embodiment, the electrode 510 may extend upon smooth lines above the clear housing 540 . The electrode 510 conducts electrical current into the hand and/or wrist and may communicate this current between any of the other wrist or hand electrodes of the present invention. In one embodiment of the present invention, the light therapy sources 520 and electrode 510 may be held rigidly in place within the clear housing 540 . Further, the light therapy sources 520 and electrode 510 may be connected internally to a printed circuit board 530 , which may deliver and route power to the light therapy sources 520 and electrode 510 . Further, the printed circuit board 530 may be electrically connected to a controller 485 .
[0049] FIG. 6 illustrates a distal therapeutic device 600 that is used to supply light therapy and electrical stimulation simultaneously to the hand and/or wrist according to one embodiment of the present invention. The distal therapeutic device 600 may include a housing 640 . The housing 640 may be constructed form a number of different materials, including, but not limited to, a solid, optically transparent material, such as ABS plastic, that is biologically safe for application to the skin. The housing 640 may be operably connected to a plurality of light sources 620 , for example lasers, LEDs and/or lamps, arranged such that illumination is permitted to extend upward or downward and into the patient's carpal tunnel region. For example, the housing may be configured so that the light therapy is directed principally at the carpal tunnel region and secondarily to the wrist at and below the ulna and radius forearm bones. When positioned within the therapy housing, the light sources 620 may be located nearer to the wrist, about and beyond the distal heads of the ulna and radius bones of the forearm. An electrode 610 made of a biologically safe material may extend upon smooth lines above the housing 640 . The electrode 610 conducts electrical current into the wrist and may communicate this current between any of the other wrist or hand electrodes of the present invention. The light sources 620 and electrode 610 may be held rigidly in place within the housing 640 , and may be connected internally to a printed circuit board 630 , which may deliver and route power to the light sources 620 and electrode 610 . The printed circuit board 630 may be electrically connected to the controller 485 .
[0050] FIG. 7 illustrates a system for aligning the light therapy and electrical stimulation of proximal and distal therapeutic devices 500 , 600 within the lower portion 300 of a therapy housing according to one embodiment of the present invention. The system of the present invention may be configured to allow the use or inclusion of any number of different therapeutic devices. In use, the wrist may be placed within the wrist channel 310 and the hand upon the hand support region 320 of the lower portion 300 of the therapy housing such that the distal heads of the ulna and radius forearm bones 105 , 110 are contained within the wrist supports 350 . The hand support region 320 of the lower portion 300 of the therapy housing may extend sufficiently to accommodate various hand and finger lengths. As shown, the carpal tunnel area 360 may extend from just before the end of the wrist supports 350 about the light therapy sources 520 of the proximal therapeutic device 500 . The proximal therapeutic device 500 may direct current into the wrist through a biologically safe conductive electrode 510 . As previously mentioned, light therapy may radiate into the wrist and carpal tunnel region via a plurality of light sources 520 . Further, the proximal therapeutic device 500 may direct current into the hand through a biologically safe conductive electrode 770 .
[0051] Light therapy may also radiate into the hand and carpal tunnel region via the distal therapeutic device 600 , which may include a plurality of light sources 620 and an electrode 610 . The plurality of light sources 620 and electrode 610 may be positioned within the therapy housing such that light and electrical stimulation is optimally delivered to a variety of wrist and hand morphologies. Further, the upper portion of the therapy housing may also include the same or similar therapeutic devices as those described above so that light and electrical stimulation therapy may be applied from both above and below the carpal tunnel region.
[0052] FIG. 8 illustrates a wrist 820 and hand 830 positioned in the lower portion 300 of a therapy housing according to one embodiment of the present invention. At least a portion of the wrist 820 may be placed within the wrist channel 310 and between the wrist supports 350 . The hand 830 may extend beyond the wrist supports 350 and lie on the hand support region 320 of the lower portion 300 of the therapy housing. The carpal tunnel area 360 is shown as extending from approximately just above the distal heads of the ulna and radius forearm bones in the wrist 820 to approximately just below the proximal heads of the metacarpal bones of the hand 830 . The proximal and distal therapeutic devices 500 , 600 are located correspondingly below the wrist 820 and hand 830 .
[0053] FIG. 9 illustrates a wrist 930 and hand 940 compressed between the upper and lower portions 410 , 300 of a therapy housing 900 according to one embodiment of the present invention. The therapy housing 900 may capture the wrist 930 and hand 940 in compression. The wrist supports 350 may be positioned and configured so as to assist in preventing the patient's wrist 930 and hand 940 from slipping out of the therapy housing 900 . As the upper and lower portions 410 , 300 of the therapy housing 900 are compressed about the wrist 930 and hand 940 , a space may exist only about the patient's carpal tunnel region such that minimal compression is exerted in this region.
[0054] FIG. 10 illustrates a rotated and compressed wrist 930 and hand 940 and a secured upper arm 1010 during use of a therapeutic system 1000 in accordance with one embodiment of the present invention. As shown, the therapeutic system 1000 may hold a patient's upper arm 1010 inline with his or her standing or seated body via an upper arm restraining device 1020 . The upper arm restraining device 1020 , which may prevent the patient's arm from moving forward, may contain a conforming foam and/or a pneumatic inflation bladder to cushion the upper arm 1010 during periods of decompressive tensile force application 1095 . The upper arm restraining device 1020 may include a tension measuring device, such as, but not limited to, a load cell or load button that may feed information regarding the decompressive tensile force 1095 exerted at the wrist 1050 and hand 1060 locations back to the controller 485 . Below the upper arm restraining device 1020 , the elbow 1030 may be bent to or near 90 degrees, and extends the forearm 1040 towards the wrist 930 and hand 940 . The wrist 1050 and hand 1060 are shown captured between the upper and lower portions 410 , 300 of the therapy housing 900 and rotated outward 90 degrees. In one embodiment, the patient's hand 940 may be positioned so that the palm is facing the patient's body. As previously mentioned, the wrist supports 350 of the therapy housing 900 may keep the wrist 930 and hand 940 from slipping out from between the therapy housing 900 during periods of decompressive tensile force application 1095 .
[0055] FIG. 11 is a top plan view of a wrist 930 and hand 940 positioned between the proximal and distal therapeutic devices 500 a , 500 b , 600 a , 600 b as they may be positioned within the therapy housing (not shown) according to one embodiment of the present invention. The lower proximal therapeutic device 600 a is shown being positioned such that the plurality of light sources 620 a are near the distal heads of the ulna and radius forearm bones and illuminate 1160 (shown as line arcs) the wrist 930 and carpal tunnel region 155 . The distal therapeutic device 600 b along the upper portion 410 may be positioned such that its plurality of light sources 620 b are near the distal heads of the ulna and radius forearm bones 105 , 110 and illuminate 1160 the wrist 930 and carpal tunnel region 155 . The lower proximal therapeutic device 500 a may be positioned such that its light therapy sources 520 a are near the proximal heads of the metacarpal bones and illuminate 1160 the hand 940 and carpal tunnel region 155 . The upper proximal therapeutic device 500 b may be positioned such that its light therapy sources 520 b are near the proximal heads of the metacarpal bones and illuminate 1160 the hand 940 and carpal tunnel region 155 .
[0056] During periods of illumination by the proximal and distal therapeutic devices 500 a , 500 b , 600 a , 600 b , which may be applied during decompressive tensile force cycles, light therapy from all of the therapeutic devices 500 a , 500 b , 600 a , 600 b may substantially illuminate 1160 the carpal tunnel region 155 .
[0057] FIG. 12 is a top plan view of a wrist 930 and hand 940 undergoing Quadripolar Interferential stimulation while positioned between proximal and distal therapeutic devices 500 a , 500 b, 600 a , 600 b according to one embodiment of the present invention. The lower distal therapeutic device 600 a may be positioned such that its electrode 610 a is near the distal heads of the ulna and radius forearm bones. This electrode 610 a may transmit a high frequency sine wave 1255 a through the wrist 930 and carpal tunnel region 155 to the electrode 510 b in the upper proximal therapeutic device 500 b. The upper distal therapeutic device 600 b may be positioned such that its electrode 610 b is near the distal heads of the ulna and radius forearm bones. This electrode 610 b may transmit a high frequency sine wave 1255 b through the wrist 930 and carpal tunnel region 155 to the hand electrode 510 a of the lower proximal therapeutic device 500 a . The lower proximal therapeutic device 500 a may be positioned such that its electrode 510 a is near the proximal heads of the metacarpal bones. This electrode 510 a may transmit a high frequency sine wave 1255 b through the wrist 930 and carpal tunnel region 155 to the electrode 610 b of the upper distal therapeutic device 600 b . The upper proximal therapeutic device 500 b may be positioned such that its electrode 510 b is near the proximal heads of the metacarpal bones. This electrode 510 b may transmit a high frequency sine wave 1255 a through the wrist 930 and carpal tunnel region 155 to the electrode 610 b of the lower distal therapeutic device 600 a.
[0058] The two high frequency sine waves 1255 a , 1255 b transmitted through the carpal tunnel region 155 may be of different frequencies (e.g. 4000 Hz and 4250 Hz). Wherever the two waveforms 1255 a , 1225 b are present, for example at a crossing 1265 at the center of the carpal tunnel region in FIG. 12 , interference may occur. Interference results in a waveform with low-frequency characteristics (a “beat frequency”) 1260 , 1270 , which radiates through and about the carpal tunnel region. 155 .
[0059] FIG. 13 is a top plan view of upper and lower proximal and distal therapeutic devices 500 a , 500 b , 600 a , 600 b positioned about a patient's wrist 930 and hand 940 that is undergoing Medium Frequency or Bipolar Interferential stimulation of the carpal tunnel region 155 according to one embodiment of the present invention. The lower distal therapeutic device 600 a may be positioned such that its electrode 610 a is near the distal heads of the ulna and radius forearm bones. The electrode 610 a of the lower distal therapeutic device 600 a may transmit a high frequency sine wave 1360 through the wrist 930 and carpal tunnel region 155 to the upper distal therapeutic device 600 b . The upper distal therapeutic device 600 b may be positioned such that its electrode 610 b is near the distal heads of the ulna and radius forearm bones. The electrode 610 b of the upper distal therapeutic device 600 b may transmit a high frequency sine wave 1360 through the wrist 930 and carpal tunnel region 155 to the electrode 610 a of the lower distal therapeutic device 600 a . The lower proximal therapeutic device 500 a may be positioned such that its electrode 510 a is near the proximal heads of the metacarpal bones. The electrode 510 of the lower proximal therapeutic device 500 a may transmit a high frequency sine wave 1360 through the wrist 930 and carpal tunnel region 155 to the upper proximal therapeutic device 500 b . The upper proximal therapeutic device 500 b may be positioned such that its electrode 510 b is near the proximal heads of the metacarpal bones. The electrode 510 b of the upper proximal therapeutic device 500 b may transmit a high frequency sine wave 1360 through the wrist 930 and carpal tunnel region 155 to the lower proximal therapeutic device 500 a.
[0060] While the invention has been described with reference to certain embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from its scope. Therefore, it is intended that the invention not be limited to the particular embodiments disclosed, but that the invention will include all embodiments falling within the scope of the appended claims.
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Embodiments of the present invention provide a system and method for delivering a plurality of modalities for the treatment of Carpal Tunnel Syndrome. Light therapy is applied to the carpal tunnel region of the hand during alternating periods of automated carpal bone structure extensions, whereby said light therapy penetrates beyond the bone structures to the carpal (volar and transverse) ligament structures, median nerve, and muscles. The light therapy is applied both above and below these structures. Simultaneously applied electrical stimulation may occurs between electrodes located both above and below various positions about the carpal tunnel region. Both light therapy and electrical stimulation are positioned optimally to affect the carpal tunnel via automated structures that provide continuous feedback to a control system. The automated structures also stimulate the flow of blood and movement of fluids associated with pressure inducing edema through the carpal tunnel region.
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LATIN NAME
BOTANICAL/COMMERCIAL CLASSIFICATION
[0001] Prunus persica ‘L. Batsch new clonal peach rootstock.
VARIETAL DENOMINATION
[0002] The varietal denomination of the claimed peach rootstock is ‘HBOK 50’.
BACKGROUND OF THE INVENTION
[0003] The present invention relates to a new and distinct cultivar of peach rootstock ( Prunus persica ) that has been denominated as ‘HBOK 50’ and more particularly to a peach rootstock that is graft compatible with peach and nectarine scion cultivars, and confers moderate vigor control on compound trees, produce fewer root suckers than ‘Nemaguard’, and is resistant to the rootknot nematode Meloidogyne incognita (race 1) isolate ‘Beltran’.
[0004] It is recognized that vigor control of compound trees on a standard rootstock, such as ‘Nemaguard’, is difficult to achieve and to do so requires extensive pruning both in mid summer and the dormant season. It is also recognized that root suckers produced on standard rootstock are required to be removed manually, resulting in cost to the grower. The ‘HBOK 50’ peach rootstock has modest vigor control that produces smaller trees, which requires less pruning, and much fewer root suckers than ‘Nemaguard’, which results in cost savings for the grower.
[0005] The peach rootstock of the present invention was created at Davis, Calif. In 1990 hybrid ‘P248-139’ was created by crossing ‘Harrow Blood’ (HB) with ‘Okinawa’ (OK) at Fresno Calif. Seeds resulting from the open pollination of a single F 1 plant from hybrid ‘P248-139’ were used to generate an experimental population (referred to as ‘OP-F 2 population’) in February of 1994. Fifty seven ‘OP-F 2 ’ seedlings were budded with ‘O'Henry’ (referred to as ‘O'Henry population’), and concurrently each of these seedlings was budded onto ‘Nemared’ rootstock (referred to as ‘OP-F 2 population’). There were no obvious defects in the bud unions indicating compatibility of scions and rootstocks at this stage. Compound trees of ‘O'Henry’ scion budded onto each seedling of the ‘OP-F 2 ’ segregating population as a rootstock were evaluated for trunk cross-sectional area (TCA), tree height, crop yield, cropping efficiency, fruit weight, and number of suckers. Eight seedlings were selected for further study of rootstock potential under semi-commercial conditions at Parlier, Calif. The primary criterion used for choosing seedlings having potential for size control as a rootstock was TCA. Wood from mother trees was propagated asexually (rooted), budded with ‘O'Henry’ peach scion and planted in a replicated field trial at Parlier, Calif. in 1999. ‘HBOK’ 50 was identified as a result of that trial, and was subsequently selected for further horticultural evaluation.
[0006] The new ‘HBOK 50’ peach rootstock of the present invention has been asexually reproduced by leaf cuttings at Davis, Calif. The distinctive characteristics of the new peach rootstock have been found to be stable and are transmitted to the new rootstocks when asexually propagated.
SUMMARY OF THE INVENTION
[0007] The ‘HBOK 50’ peach rootstock of the present invention has a peach pedigree (vs. inter-specific heritage) and offers size control ability, root knot nematode resistance, less wood from dormant and summer pruning, and production of fewer root suckers. When used as clonally-produced rootstocks with fresh market peach (‘O'Henry’ and ‘Springcrest’), cling peach (‘Ross’), and nectarine (‘Mayfire’ and ‘Summer Fire’) scions, they have contributed to size reduction of compound trees and no evidence of graft incompatibility or other abnormalities have been noted. Based on reduced tree height and smaller trunk cross-sectional area (TCA) compared to standard rootstocks, ‘HBOK 50’ had about a 7-8% size reduction. Although crop yield per tree usually was less than on ‘Nemaguard’ rootstock, the compound trees with ‘HBOK 50’ rootstocks that were smaller generally showed greater cropping efficiency. Ability to plant smaller trees at greater density in commercial fields provides an opportunity to recover economically viable yields per unit area. Fruit on compound trees with ‘HBOK 50’ rootstocks was either similar in size or smaller than ‘Nemaguard’. The ‘HBOK 50’ rootstock displays root knot nematode resistance levels similar to ‘Nemaguard’ and more resistance than ‘Lovell’. Compound plants with ‘HBOK 50’ rootstocks provide an opportunity for growers to develop new management practices that utilize the potential of these rootstocks to lower costs through size reduction, reduced pruning and less need for sucker control.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 shows a severely cut back tree of ‘HBOK 50’ with an abundance of vigorous, strait vegetative shoots, providing a large quantity of propagation materials for stem cuttings.
[0009] FIG. 2 shows the trunk of ‘HBOK 50’ grafted on ‘Nemared’ rootstock. The graft union here is indistinguishable.
[0010] FIG. 3 shows the trunk, scaffolds, and upper spreader branches of ‘HBOK 50’ grafted on ‘Nemared’ rootstock. The green color on the scaffolds is caused by algae growth, since the picture was taken in the cool wet winter.
[0011] FIG. 4 shows small and flattened bark lenticels from ‘HBOK 50’ wood. Bark lenticels are present on two to four year old wood of ‘HBOK 50’.
[0012] FIG. 5 shows a terminal piece of a branch of ‘HBOK 50’ showing newly made leaves.
[0013] FIG. 6 shows fruits of the ‘HBOK 50’ rootstock.
[0014] FIG. 7 shows flowers and flower buds of the ‘HBOK 50’ rootstock at different stages.
DETAILED DESCRIPTION OF THE INVENTION
[0015] The peach rootstocks ‘HBOK 10’, ‘HBOK 32’ and ‘HBOK 50’ were developed to be improved rootstocks with size control capability and pest resistance. These three peach rootstocks were developed by: 1) screening Prunus populations for compatibility with and growth controlling potential for peach and nectarine along with resistance to nematodes, crown gall and bacterial canker, 2) hybridizing parents with these traits and beginning selection in segregating populations for individuals that possess desired trait combinations, 3) identifying individual plants that are useful as asexually propagated clonal rootstocks, and 4) assessing the potential of the best materials for commercial peach and nectarine rootstocks.
[0016] ‘Okinawa’ peach was identified as a parent for its resistance to the nematodes M. incognita and M. javanica. Additionally it has a low chill requirement resulting in early blooming and presumably early seed germination. It is not known to be size controlling and it is an open, standard-type tree on its own root. ‘Harrow Blood’ peach, selected in Canada as a rootstock, was chosen as a second parent because it was reported to have dwarfing effect on scions in early years of tree growth. It is susceptible to root-knot nematode, has a high chill requirement (late bloom), produces fruit with red flesh and is a small, ‘twiggy’ tree. The cross of ‘Harrow Blood’ and ‘Okinawa’ was previously performed in 1990 at Fresno, Calif. (USDA-ARS), and an F 1 hybrid of that cross was used.
[0017] An experimental population (referred to as ‘OP-F 2 population’) derived from open pollination in 1994, of a single F, plant (No. P248-139) of the cross ‘Harrow Blood’ (HB)בOkinawa’ (OK) was generated and used.
[0018] Detailed research findings leading to the selection of the mother plants of the three rootstocks are presented in Gillen (2001). Briefly, 57 ‘OP-F 2 ’ seedlings were budded with ‘O'Henry’ (referred to as ‘O'Henry population’) and concurrently each of these seedlings was budded onto ‘Nemared’ rootstock (referred to as ‘OP-F 2 population’) in 1995 and planted in spring 1996. Successful bud unions of 49 seedling pairs (98 paired plants) were produced for which tree characters were measured during 1997, 1998, and 1999. There were no obvious defects in the bud unions indicating compatibility of scions and rootstocks at this stage.
[0019] A commercial nursery prepared the ‘OP-F 2 population’ by field budding a scion of each F 2 plant onto ‘Nemared’ seedlings. The ‘O'Henry population’ was prepared at Davis, Calif., by budding ‘O'Henry’ onto each of the segregating seedlings which were grown in pots until transplanted to the field. After transplanting, the main stems of all plants were pruned to approximately 24 inches and primary lateral branches to about 18 inches. Although the two populations, ‘OP-F 2 ’ and ‘O'Henry’ were handled differently at the outset, trees within each population received uniform treatment to facilitate detection of genetic differences.
Root knot nematode resistance screen
[0021] The root knot nematode resistance response of each ‘OP-F 2 ’ seedling in the segregating population was determined from a progeny test in which open-pollinated (F 3 ) seedlings from each ‘OP-F 2 ’ plant were inoculated with live root-knot nematodes and scored for their reaction. Based on whether the ‘OP-F 3 ’ family was all resistant, all susceptible, or segregating, the ‘OP-F 2 ’ plant was considered to be homozygous resistant, homozygous susceptible or heterozygous, respectively assuming reaction to be controlled by a single gene. Preparation and application of inoculum and procedures for growing and scoring the plants and details of the screening procedure are presented in Gillen (2001). Based on the response phenotypes of the OP-F 3 families, the ‘OP-F 2 population’ segregated 9 homozygous resistant, 26 heterozygous, 12 homozygous susceptible, and two plants were unable to be scored. This segregation pattern was consistent with control by a single dominant gene (Chi Squared Goodness-of-fit Test; df=46, p=0.63). The seedlings 94-94-10 and 94-94-50 were scored as heterozygous resistant and 94-94-32 homozygous resistant for root knot nematode reaction (Gillen, 2001).
Seedling selection for size control potential
[0023] Compound trees consisting of ‘O'Henry’ scion budded onto each seedling of the ‘OP-F 2 ’ segregating population as a rootstock were planted at Davis, Calif. In 1997, 1998, and 1999, trees were evaluated for trunk cross-sectional area (TCA), tree height, crop yield, cropping efficiency, fruit weight and number of suckers. The size control phenotypes (TCA and tree height) of the seedlings in the segregating population showed a continuous distribution (measured as percentage of mean TCA of the standard) and no discrete segregation pattern was seen in this population.
[0024] Eight seedlings were selected based on the trials at Davis, Calif., for further study of rootstock potential under semi-commercial conditions at Parlier, Calif. The primary criterion used for choosing seedlings having potential for size control as a rootstock was TCA, since that is considered to be a better measure of bearing surface of a tree than height (Westwood, 1978). Wood from mother trees was propagated asexually (rooted), budded with ‘O'Henry’ peach scion and planted in a replicated field trial at the KAC in 1999, details of which are discussed in Gillen (2001). A total of 20 trees of each rootstock/scion combination were planted and trained to the perpendicular V system. Between-row spacing of 5.49 m (18 ft) was the same for all rootstock/scion combinations, and in-row spacing was 2.13 m (7ft) between trees for all treatments. Four replications of 5 trees each were arranged according to a randomized complete block design. Data collected for plant height and TCA in 1999 showed that among the 8 entries, 94-94-10 (‘HBOK 10’), 94-94-32 (‘HBOK 32’), and 94-94-50 (‘HBOK 50’) were significantly smaller than the control in both 1999 and 2000 (Gillen, 2001). Data collection on 94-94-7 and 94-94-44 was discontinued after 1999. After 2000, testing was discontinued on 94-94-5 and 94-94-48, since they appeared to be the least promising (Table 1). During the four years of this trial tree height and TCA of the three experimental stocks were less than that of the controls (mean values of ‘Nemaguard’ and ‘Lovell’). At the 2003 harvest year (5 th leaf), 94-94-32 showed the most potential for size control followed by 94-94-10 and 94-94-50. 94-94-32 and 94-94-10 were significantly smaller than the control for all years (Table 1). Though 94-94-50 was smaller than the controls in all years it was not significantly so in 2003. In general, fruit weight was not different among trees with experimental rootstocks and the controls. Yield was consistently lower on the experimental rootstocks than the controls, though not always significantly less (Table 1). Pruning weights and suckering were less for the experimental rootstocks.
[0025] Table 1 below shows mean values for tree height, trunk cross sectional area (TCA), crop yield, fruit weight, cropping efficiency, winter pruning weight, and summer pruning weight of second-leaf through fifth-leaf ‘O'Henry’ peach scions on five ‘HBOK’ rootstocks and the control and mean number of root suckers on each of the rootstocks. Trees were planted at Parlier, Calif., in 1999.
[0000]
TABLE 1
Crop yield
Fruit weight
Tree height (cm)*
TCA (cm2)*
(kg/tree)*
(g/fruit)
Rootstock
Mean*
S.E.M.
Mean
S.E.M.
Mean
S.E.M.
Mean
S.E.M.
Harvest year: 2000 (2nd leaf)
94-94-5**
303.0
ab
10.08
33.6
ab
3.41
1.3
bc
0.18
179
a
6.05
94-94-10**
237.0
c
19.18
16.4
c
2.95
0.5
c
0.11
158
ab
11.10
94-94-32**
216.0
c
15.33
13.5
c
2.32
0.5
bc
0.07
134
b
5.42
94-94-48**
300.0
ab
21.60
29.1
ab
5.18
1.9
b
0.37
180
a
24.45
94-94-50**
260.0
bc
10.73
23.8
bc
2.28
0.7
bc
0.14
147
ab
14.00
Control***
326.0
a
12.41
35.4
a
3.63
5.7
a
0.61
180
a
10.16
Harvest year: 2001 (3rd leaf)
94-94-10****
272.1
b
18.59
27.6
b
5.85
11.6
b
2.23
141.7
a
7.52
94-94-32****
267.0
b
19.17
23.0
b
3.82
9.4
b
1.52
141.0
a
5.70
94-94-50****
321.5
ab
17.36
39.2
b
4.19
14.2
b
1.34
154.9
a
5.39
Control
380.5
a
19.66
60.2
a
6.09
24.4
a
1.78
147.0
a
5.02
Harvest year: 2002 (4th leaf)
94-94-10
345.0
b
25.57
41.8
b
8.01
19.7
b
3.37
179.2
a
8.81
94-94-32
313.5
b
27.76
30.4
b
5.84
16.5
b
1.89
180.3
a
4.70
94-94-50
357.7
b
15.25
52.6
b
5.19
22.2
ab
2.11
194.6
a
6.89
Control
417.5
a
12.55
77.4
a
8.12
29.6
a
2.60
179.7
a
11.48
Harvest year: 2003 (5th leaf)
94-94-10
387.5
b
41.0
54.6
bc
9.76
33.8
ab
3.24
190.6
a
9.51
94-94-32
355.0
b
22.8
41.3
c
6.81
26.6
b
2.96
193.4
a
7.20
94-94-50
407.7
ab
19.1
73.1
ab
5.54
38.0
ab
1.61
211.6
a
5.20
Control
441.8
a
28.7
94.0
a
13.22
40.1
a
2.62
203.2
a
8.77
Cropping
Winter pruning
Summer pruning
Root suckers
efficiency (Crop
weight
weight (kg/tree)*
(number/tree)
Rootstock
Mean
S.E.M.
Mean
S.E.M.
Mean
S.E.M.
Mean
S.E.M.
Harvest year: 2000 (2nd leaf)
94-94-5**
0.03
a
0.01
5.2
a
0.72
no data
0.0
c
0.0
94-94-10**
0.03
a
0.01
1.8
cd
0.66
0.6
b
0.1
94-94-32**
0.40
a
0.01
1.2
d
0.31
0.0
c
0.0
94-94-48**
0.07
a
0.02
3.8
abc
1.23
0.0
c
0.0
94-94-50**
0.95
a
0.01
2.2
bcd
0.55
0.0
c
0.0
Control***
0.20
a
0.03
4.2
ab
0.75
1.4
a
0.7
Harvest year: 2001 (3rd leaf)
94-94-10**
0.43
a
0.03
2.3
b
0.92
no data
0.0
b
0.0
94-94-32**
0.44
a
0.07
1.5
b
0.43
0.0
b
0.0
94-94-50**
0.40
a
0.04
3.3
ab
0.70
0.0
b
0.0
Control
0.46
a
0.03
5.8
a
0.90
0.8
a
0.9
Harvest year: 2002 (4th leaf)
94-94-10
0.50
ab
0.03
8.2
b
2.32
9.6
b
3.5
0.0
b
0.0
94-94-32
0.67
a
0.13
5.4
b
1.54
10.4
b
2.5
0.0
b
0.0
94-94-50
0.44
b
0.04
11.1
b
1.42
12.2
b
2.2
0.0
b
0.0
Control
0.46
b
0.05
17.3
a
1.97
21.8
a
1.9
0.9
a
0.5
Harvest year: 2003 (5th leaf)
94-94-10
0.68
a
0.08
4.1
ab
1.28
0.9
b
0.19
0.00
b
0.0
94-94-32
0.77
a
0.14
2.4
b
0.73
0.6
b
0.11
0.00
b
0.0
94-94-50
0.57
a
0.04
4.8
ab
0.50
1.3
b
0.10
0.00
b
0.0
Control
0.53
a
0.10
6.8
a
1.12
2.3
a
0.55
0.9
a
0.5
*Means within column and year with the same letter(s) are not significantly different according to Duncan's Multiple Range Test P ? 0.05.
**Data were collected on these five HBOK rootstocks only. out of original eight, because the other three were tested to be susceptible to root-knote nematode.
***Control is the average of values of Nemaguard and Lovell rootstocks together.
****Data on these three HBOK rootstocks only were collected, starting in 2001, because these were the ones that showed promise as tree size-reducing rootstocks.
Resistance of clonal propagules to root-knot nematode in greenhouse pot tests
[0027] In 2006, reactions of clonal propagules of 94-94-10 (‘HBOK 10’), 94-94-32 (‘HBOK 32’), and 94-94-50 (‘HBOK 50’) to the root-knot nematode M. incognita (race 1) isolate ‘Beltran’ were recorded in a greenhouse pot test. Leafy cuttings were taken from each of the three mother trees and rooted. Cuttings were grown for ten months in a greenhouse then given a chilling treatment by growing outside for another two months. Each was repotted in sand while dormant, then grown for another month in a greenhouse before nematode inoculation. A single inoculation with the isolate was made following procedures for inoculum preparation and inoculation as described by Gillen (2001) on Mar. 15, 2006. The test was evaluated after about five months of incubation, on Aug. 9, 2006. Entire root systems of each cutting were scored for gall formation and rated according to system of Sherman et al. (1981).
[0028] The mean scores for entries in this experiment ranged from 0 (considered to be resistant) to 5.0 (susceptible) (Table 2). The two standards ‘Lovell’ and ‘Nemaguard’ had mean scores similar to what was expected based on their known reactions. Among the three experimental rootstocks, 94-94-50 (‘HBOK 50’) had a mean score of 0, slightly better than ‘Nemaguard’, while the scores of 94-94-10 (‘HBOK 10’) and 94-94-32 (‘HBOK 32’) were comparable to ‘Nemaguard’ (Table 2). These results were consistent with those obtained from the seedling screen conducted earlier by Gillen (2001).
[0029] Based on data over several years of trials at Davis, Calif., and Parlier, Calif., the mother trees, 94-94-10 (‘HBOK 10’), 94-94-32 (‘HBOK 32’) and 94-94-50 (‘HBOK 50’) were chosen as sources of asexual propagules for additional field trials, planted in 2003 and 2004, to determine their potential as rootstocks for peach and nectarine.
[0030] The productivity of compound trees having peach and nectarine scion cultivars on ‘HBOK 10’, ‘HBOK 32’, and ‘HBOK 50’ and standard ‘Nemaguard’ were compared in several field trials in California. The results are summarized below.
[0031] Table 2 below shows Nematode reaction of rooted cuttings of selected clones of experimental lines compared to standard rootstocks ‘Lovell’ and ‘Nemaguard’ in greenhouse pot tests, conducted March-August, 2006.
[0000]
TABLE 2
Cultivar or clone
Number of plants
Mean score
S.E.M.
Lovell
12
4.75
0.18
Nemaguard
12
0.17
0.11
28-3
12
3.58
0.62
29-31
13
0.23
0.12
94-94-10
12
0.17
0.11
94-94-32
12
0.33
0.14
94-94-50
12
0
0
2-6
12
5.0
0
3-6
12
1.0
0
Scores: 0 =no galls present on roots;
1 = 1 to 5 galls;
2 = 6 to 10 galls;
3 = 11-15 galls;
4 = 16 to 20 galls;
and 5 = more than 20 galls.
Performance of ‘HBOK 10’, ‘HBOK 32’, and ‘HBOK 50’ in field trials
[0033] ‘HBOK 10’, ‘HBOK 32’, and ‘HBOK 50’ rootstocks were among several studied in field trials. Data for only ‘HBOK 50’, the standard rootstock ‘Nemaguard’, and in some cases, other rootstocks where a comparison is meaningful, are presented. Data for all entries in the field trials are found in DeJong et al. (2005, 2006, 2007, and 2008).
[0034] Most of the propagation of these experimental materials for the field experiments was by leafy cuttings at Davis, Calif. Rooted materials were then potted and budded, with chosen scion cultivars, in greenhouses. Compound plants were provided during the winter for planting the following spring.
Performance of ‘O'Henry’ peach scion on different rootstocks
[0036] A field trial was established at Parlier, Calif., in February 2003 to measure growth and productivity of compound trees of which the scion cultivar ‘O'Henry’ peach was bud grafted onto different rootstocks, including ‘HBOK 10’, ‘HBOK 32’, and ‘HBOK 50’ for comparisons to the standard rootstock ‘Nemaguard’ and to others either being tested or in commercial use. A total of 20 trees of each rootstock/scion combination were planted and trained to the perpendicular V system. Between-row spacing of 5.49 m (18 ft) was the same for all rootstock/scion combinations, and in-row spacing was 2.13 m (7ft) between trees for all treatments. Four replications of 5 trees each were arranged according to a randomized complete block design.
[0037] The soil at the site is a well-drained Hanford fine sandy loam. The trees were provided supplemental moisture with micro-sprinklers to maintain 100% of potential evapo-transpiration prior to harvest and about 80% after harvest. Supplemental nutrients were provided by applying UN 32 through irrigation at a rate of 5 gal per acre per application of 2 to 3 applications per year until the trees were 2 years old. Beginning in year three, 250 lb per acre of ammonium nitrate was applied each fall. Pesticides were applied according to standard horticultural practices. Weeds were controlled by mowing the row middles and applying herbicides to maintain a 1.5 m wide weed-free strip down the tree rows.
[0038] Trees were pruned in May and late November according to standard recommendations for growing the trees. Severity of pruning was adjusted according to the growth characteristics of each rootstock/scion combination to optimize crop production while developing/maintaining the desired tree shape. The first significant fruit set occurred in the third leaf and crop load was adjusted for tree size by hand thinning to maintain a minimum spacing between fruit. Because patterns of fruit maturity varied among rootstocks, fruit were harvested in several picks but data were combined from all harvests to calculate mean fruit yield. Data on crop load (fruit per tree) and fruit size were also recorded.
Results
[0040] The six rootstocks compared beginning at the 3 rd-leaf ( 2005 harvest year) and continuing through the 6 th -leaf had differences in tree height and TCA among the compound trees (Table 3). Trees on ‘Nemaguard’ were the largest throughout. Trees on ‘1-1130K 10’ and ‘HBOK 32’ were smaller than ‘Nemaguard’ and similar to ‘Ishtara’, which is known for size controlling, potential (Table 3). ‘HBOK 50’ was shorter than ‘Nemaguard’ except in harvest year 2007 and although the TCA was less than ‘Nemaguard’ each year, the difference was significant only in 2005 (Table 3). ‘Cadaman’ was included for comparison because it has a level of resistance to nematodes but as seen here, trees are of similar size to ‘Nemaguard’ (Table 3). ‘Ishtara’, which has some nematode resistance, showed reduced tree height and smaller TCA than ‘Nemaguard’. ‘Cadaman’ is a peach×almond hybrid and ‘Ishtara’ a peach×plum hybrid.
[0041] Cropping efficiency of ‘HBOK 10’ and ‘HBOK 32’ was greater than of ‘Nemaguard’ in 2006 through 2008, but significant only for ‘HBOK 32’ (Table 3). Fruit weight was slightly less also. Each of the four years, the amount of material removed during both summer and dormant pruning from ‘HBOK 10’ and ‘HBOK 32’ was significantly less than from ‘Nemaguard’, and usually there was less pruned material from trees on ‘HBOK 50’ (Table 3). All three rootstocks produced significantly fewer root suckers than ‘Nemaguard’ each year.
[0042] Table 3 below shows mean values for tree height, trunk cross sectional area (TCA), crop yield, fruit weight, cropping efficiency, winter pruning weight, and summer pruning weight of third-leaf through sixth-leaf ‘O'Henry’ peach scions on six different rootstocks and mean number of root suckers on each of the rootstocks. Trees were planted at the Parlier, Calif., in 2003.
[0000]
TABLE 3
Crop yield
Fruit weight
Tree heigh (cm)*
TCA (cm2)*
(kg/tree)*
(g/fruit)*
Rootstock
Mean*
S.E.M.
Mean
S.E.M.
Mean
S.E.M.
Mean
S.E.M.
Harvest year: 2005 (3rd leaf)
HBOK 10
342
b
9.1
43.4
c
4.4
7.7
b
1
255
cd
5.5
HBOK 32
337
b
7.1
33.9
d
1.6
7.1
b
1.7
250
d
2
HBOK 50
367
b
2.4
58.7
b
4.7
10.1
b
1.5
251
d
15.2
Nemaguard
402
a
5
68.8
a
2.9
14.3
a
1.5
268
cb
7
Cadaman
383
a
7.1
59.9
b
2.8
14.5
a
1.7
283
b
7.4
Ishtara
333
b
7.1
36.8
dc
2.2
6.2
b
0.6
298
a
5.9
Harvest year: 2006 (4th leaf)
HBOK 10
428
b
9.2
52.7
b
4.3
24.1
c
1.3
191
bc
2.8
HBOK 32
421
b
8.1
46.2
b
2.3
24.5
c
0.7
188
c
5.1
HBOK 50
459
b
5.2
73.4
a
2.8
30.2
b
1.1
192
b
2.5
Nemaguard
502
a
4.1
82.9
a
2.8
33.9
a
0.8
206
a
3.8
Cadaman
479
ab
6.2
73.5
a
3.2
33.0
a
0.4
191
b
5.7
Ishtara
416
b
8.3
49.7
b
2.9
29.5
b
0.8
188
c
2.1
Harvest year: 2007 (5th leaf)
HBOK 10
390
cb
9.4
68.3
b
5.7
45.1
c
1.9
208.2
bc
3.4
HBOK 32
376
cd
8.7
59.1
b
3.3
50.8
b
0.9
194.5
c
6.8
HBOK 50
424
a
7.5
102.3
a
5.3
58.0
a
0.4
199.8
c
11.7
Nemaguard
432
a
3.4
104.1
a
4.3
60.4
a
1.2
240.5
a
5.2
Cadaman
409
b
5.8
100.2
a
5.5
61.1
a
0.8
220.2
b
5.7
Ishtara
361
d
9.4
64.3
b
3.6
47.6
bc
2
197.4
c
1.7
Harvest year: 2008 (6th leaf)
HBOK 10
425.6
c
9.8
83.5
b
6.6
45.7
d
1.1
205
b
5.9
HBOK 32
383.6
d
6.8
73.2
b
3.9
47.7
dc
2.2
218.7
b
4.6
HBOK 50
450
b
6.1
111.6
a
6
50.4
c
1.3
216.4
b
5.4
Nemaguard
490.9
a
9.7
119.9
a
4.7
56.5
b
0.9
221.7
ab
5.4
Cadaman
462.7
b
8.9
112.9
a
5.3
62.2
a
1.5
235.2
a
6.5
Ishtara
394.7
d
6.8
71.2
b
3.7
41.2
e
1.3
207.5
b
6.6
Cropping efficiency
Winter pruning
Summer pruning
Root suckers
(Crop yield/TCA)*
weight (kg/tree)*
weight (kg/tree)*
(number/tree)*
Rootstock
Mean
S.E.M.
Mean
S.E.M.
Mean
S.E.M.
Mean
S.E.M.
Harvest year: 2005 (3rd leaf)
HBOK 10
0.21
a
0.04
4.1
b
0.5
1.1
c
0.2
0.3
b
0.1
HBOK 32
0.21
a
0.05
2.4
c
0.2
0.7
c
0.1
0
b
0
HBOK 50
0.18
a
0.03
4.3
b
0.4
0.9
c
0.3
0.1
b
0
Nemaguard
0.21
a
0.02
5.8
a
0.1
2.1
a
0.2
3.8
a
0.1
Cadaman
0.26
a
0.03
5.6
a
0.4
1.6
b
0.1
4.4
a
1
Ishtara
0.17
a
0.02
2.5
c
0.2
0.9
c
0.1
0
b
0
Harvest year: 2006 (4th leaf)
HBOK 10
0.49
bc
0.04
5.7
b
0.4
0.5
b
0
0.3
b
0.1
HBOK 32
0.55
ab
0.03
3.4
c
0.2
0.3
c
0.1
0
b
0
HBOK 50
0.40
d
0.02
6.4
b
0.4
0.5
b
0
0.1
b
0
Nemaguard
0.41
d
0.01
8
a
0.3
0.6
a
0
3.8
a
0.1
Cadaman
0.45
dc
0.02
8
a
0.7
0.7
a
0
4.4
a
1
Ishtara
0.59
a
0.04
2.9
c
0.1
0.2
d
0
0
b
0
Harvest year: 2007 (5th leaf)
HBOK 10
0.66
cb
0.05
6.7
c
0.2
2.6
b
0.3
0.3
b
0
HBOK 32
0.86
a
0.05
6
d
0.2
1.9
cb
0.4
0
b
0
HBOK 50
0.62
c
0.04
9.4
ab
0.7
4.0
a
0.7
0.1
b
0
Nemaguard
0.58
c
0.03
10.1
a
0.3
3.8
a
0.6
4.1
a
0.4
Cadaman
0.61
c
0.03
8.4
b
0.4
3.8
a
0.5
4.1
a
0.8
Ishtara
0.74
b
0.05
4.2
e
0.1
1
c
0.2
0
b
0
Harvest year: 2008 (6th leaf)
HBOK 10
0.59
ab
0.04
5.8
c
0.4
0.5
bc
0.05
0.3
b
0
HBOK 32
0.67
a
0.03
4.4
d
0.27
0.3
dc
0.05
0
b
0
HBOK 50
0.46
c
0.02
7
b
0.5
0.81
a
0.07
0.1
b
0
Nemaguard
0.48
c
0.02
8.9
a
0.3
0.65
ab
0.1
4.4
a
0.4
Cadaman
0.56
b
0.02
8.5
a
0.4
0.64
ab
0.09
4.1
a
0.8
Ishtara
0.6
ab
0.03
2.1
e
0.2
0.13
d
0
0.1
b
0
*Means within column and year with the same letter(s) are not significantly different according to Duncan's Multiple Range Test P ≦ 0.05
Discussion
[0044] In this trial ‘HBOK 10’ and ‘HBOK 32’ showed consistent measures of tree height and TCA that are indicative of size controlling rootstocks for peach. Although compound plants with ‘HBOK 50’ were smaller than the checks in the previous trial with ‘O'Henry’ scions and generally so in this trial, the differences were not always significant.
[0045] The ‘HBOK 50’ rootstock appears to give a small reduction in size, which may make it be more appropriate for use as a rootstock for almond scions, since both ‘HBOK 10’ and ‘HBOK 32’ would give too great of a reduction. Also the root-knot nematode resistance of ‘HBOK 50’ would be valuable if used with an almond scion.
Nematode response of rootstocks in field trials
[0047] Trees of ‘HBOK 10’ and ‘HBOK 50’ were determined to be heterozygous resistant and ‘HBOK 32’ homozygous resistant to root-knot nematodes based on reactions of OP-F3 progeny seedlings from each inoculated with nematodes (Gillen, 2005) and levels of resistance comparable to ‘Nemaguard’ were confirmed in subsequent pot tests. Although field tests were not conducted to determine reaction to root-knot nematode, available data from other sources describe ‘HBOK’ rootstock response to root knot nematode and other nematodes that infest roots of Prunus crops.
[0048] Clonal propagules of these rootstocks have been included in several field trials conducted at Parlier, Calif., and other sites. The results of a nematode screening field trial conducted in 2004 are shown in Table 4 below. ‘HBOK 10’ and ‘HBOK 32’ had levels of response to root-knot nematode similar, but slightly less resistant than ‘Nemaguard’. ‘HBOK 50’ showed no symptoms in the single repetition in that trial.
[0049] Table 4 below shows the response (nematodes/g root, fw) of six rootstocks to root lesion and root-knot nematodes in field trials during 2004.
[0000]
TABLE 4
Root lesion and
Root lesion only
Root-knot only
Root-knot
Rootstock
Mean
S.E.M.
Mean
S.E.M.
Mean
S.E.M.
HBOK 10
0.03
0.02
0.09
0.07
0.12
0.09
HBOK 32
0.91
0.79
0.77
0.71
1.68
0.88
HBOK 50
0.35 a
—
0
—
0.35
—
Nemaguard
0.72
0.35
0
0
0.7
0.35
Cadaman
0.01
0.01
0
0
0.01
0.01
Ishtara
22.46
4.12
0.02
0.02
22.48
4.1
[0050] The field trial included planting out 20 seedlings into an open field of Hanford sandy loam soil. Six seedlings were inoculated with root knot by itself, 6 were inoculated with root lesion by itself and the remaining 8 were inoculated with the combination of the two nematodes but from a different source that came from a ‘Nemaguard’ replant setting. If four or five more seedlings were available, and if adequate space was available, the four or five seedlings were planted into sandy soil containing ring nematode plus a single ‘Nemaguard’ adjacent to each of the five. Tree roots and above-ground biomass were assessed by using a backhoe to exhume the entire tree, usually at 6 months 12 months, and 18 months after planting. Young roots were collected from all along each root system. A 20 gram sample of diced root tips was placed in a funnel within a mist chamber for five days and nematodes forced to migrate through tissue paper into the test tubes. Nematodes were counted and identified as to species. The population of root-knot, Meloidogyne incognita was aggressive, the population of root lesion, Pratylenchus vulnus was moderately aggressive, and the population of ring nematode, Criconemoides xenoplax was moderately aggressive.
[0051] Additional data suggests that these three rootstocks have useful resistance to root-knot nematode and possibly to other nematodes as well. In “A Report to the California Tree Fruit Agreement—A greater number of rootstock choices can provide a partial alternative to methyl bromide fumigation ” (McKenry, Dec. 30, 2007) it states, “One selection, ‘HBOK-10’, was as resistant to root-knot as ‘Nemaguard’ but supported half the number of root-lesion as ‘Nemaguard’.” In 2008, McKenry reported that ‘HBOK 10’ showed only 0.08 root-knot nematodes per gram of root compared to 0 for ‘Nemaguard’, ‘Okinawa’, ‘Cadaman’, and ‘Ishtara’, and 31 for ‘Lovell’ (McKenry, 2008). In the same report, a 2-year study showed few or no root-knot nematodes on ‘HBOK 10’ and ‘HBOK 50’, respectively, the latter being similar to ‘Nemaguard’. There were few root lesion nematodes Pratylenchus vulnus per gram of root on ‘HBOK 10’, similar to numbers on ‘Nemaguard’, ‘Lovell’, ‘Okinawa’, ‘Cadaman’ and ‘Ishtara’, while ‘HBOK 50’ had higher levels than ‘Nemaguard’ (McKenry, 2008). In a field trial in Stanislaus County, Calif., ‘HBOK 32’ roots had fewer ring nematodes and root lesion nematodes and a similar amount of root-knot nematodes than ‘Nemaguard’ (McKenry, 2007).
[0052] Based on the seedling responses, ratings made in a pot test and the limited field studies, it is believed that ‘HBOK 10’, ‘HBOK 32’, and ‘HBOK 50’ have useful levels of resistance to root-knot nematode. The observations reported by McKenry suggest that they may have useful levels of resistance to some other nematodes.
Propagation of ‘HBOK 10’, ‘HBOK 32’, and ‘HBOK 50’ for rootstocks
[0054] Asexual propagation of peach rootstock planting materials is usually peformed by one of three methods: leafy cuttings, hardwood (dormant) cuttings and tissue culture. Most of the propagation of these experimental materials for the field experiments was by leafy cuttings at Davis, Calif.
Propagation via leafy cuttings
[0056] Materials were propagated using leafy cuttings. Stems were collected from June through August. They were cut into segments 6 to 10 inches long and the leaves near the base stripped away. Cuttings were then dipped in 1000 ppm IBA (dissolved in 50% ethyl alcohol) for five seconds and the base then placed in a soil-less mix of 1 part vermiculite and 2 parts perlite in propagation flats. Flats were placed under mist, with the frequency of misting regulated by an artificial leaf Rooting occurred in about two to three weeks.
Propagation via hardwood (dormant) cuttings
[0058] Materials were propagated using hardwood cuttings. Current year shoots were collected in the middle of November. They were cut to 14 inch long and the basal ends soaked for 24 hours in a 100 ppm IBA. They were then placed in moist burlap bags, which were then placed in plastic bags, securely closed with a wire, and incubated at about 60° F. Cuttings were inspected every week starting after the second week of incubation. When the bases of most cuttings were covered with callus, they were planted in paper sleeves with soil-less mix of three parts fir bark and one part sand. They were placed under cover to protect from rain and watered whenever needed.
Propagation via tissue culture
[0060] Materials were propagated using tissue culture. The procedures involved collecting young shoots, usually in April, and then sterilizing them with a surface sterilizing agent such as common household bleach. The shoots were then rinsed several times with sterile water, cut into small pieces each containing vegetative terminal or auxiliary buds. These cuttings were then placed in special media for tissue establishment. They were transferred into shoot multiplication medium where auxiliary shoots proliferate in numbers dependent on the type of rootstock. These multiplied shoots were cut and placed in a rooting medium to produce complete plants. The plants were taken out from the test tubes, where they were grown in the laboratory, placed in trays with soil-less mix and transferred into a greenhouse with fogging system for hardening. These were individually potted and transferred to a regular greenhouse where they were budded with different Prunus tops, grown till winter, and sold to farmers.
BOTANICAL DESCRIPTION OF THE PLANT
[0061] An experimental population (referred to as ‘OP-F2 population’) derived from open pollination in 1994, of a single F1 plant (No. P248-139) of the cross ‘Harrow Blood’ (HB)בOkinawa’ (OK) was subsequently brought to Davis, Calif. The rootstock ‘HBOK 50’ resulted from a single plant (94-94-50) selected from that population at Davis, Calif. and subsequently propagated asexually to be studied as a rootstock.
[0062] The following horticultural description was developed from plant material of this new rootstock cultivar growing at Davis, Calif. Trees of ‘HBOK 50’ were observed for description during 2008 growing season. At that time, the trees were growing for the twelfth year. Color definition used throughout the following botanical description of this rootstock was set by Munsell Color Chart for Plant Tissues standards.
Tree:
Tree.— The tree from which this description is taken was grafted on ‘Nemared’ and planted at the Davis, Calif., in 1996. It was used as a source from which to propagate the new rootstock for experimental tests and plantings. The propagated tree was grown in a V-shaped training system for two years. Since then, the tree has received rather severe annual pruning to keep it in a highly vegetative state. The heavy pruning favors the development of many long straight shoots especially suited for the production of clonal rooted cuttings ( FIG. 1 ). The trees of the subject new cultivar are vigorous and hardy under typical Sacramento Valley, Calif. climatic conditions.
Trunk:
Trunk.— The ‘HBOK 50’ scion was grafted on ‘Nemared’ rootstock and the union between the two peach accessions was so complete that the point of the graft union, after twelve years, was undistinguishable ( FIG. 2 ). The circumference of the ‘HBOK 50’ trunk, 20 cm above the soil level, averages 64 cm. The trunk surface is coarse and has moderate number of cracks. Trunk color is green yellow (2.5 GY7/2 by Munsell Color Chart for Plant Tissues standards).
Branches:
Branches.— The tree branches have the normal thickness of a peach. The primary scaffolds arising from the trunk range from 30 to 35 cm in circumference measured at the base. Color of the main scaffolds is yellow red (2.5YR 7/2 Munsell Color Chart for Plant Tissues standards). Base circumference of upper spreader limbs ranges from 10 to 13 cm ( FIG. 3 ). Lower and smaller fruit hangers wood bases range from 1.5 to 2 cm in circumference. Older branch surfaces are netted and lightly furrowed. Surface color of four year old branches ranges from red (2.5R 4-11 to 2.5R5-4 by Munsell Color Chart for Plant Tissues standards). Numerous small and flattened bark lenticels are present in two to four year old wood and absent on one year and older than four year old wood ( FIG. 4 ) Lenticels range from 0.5 to 1 mm in width and 2 mm in length. Their color is yellow red (7.5YR 8/2 by Munsell Color Chart for Plant Tissues standards).
Leaves:
Leaves.— The length of leaves, selected from the middle of shoots bearing fruits, ranges between 11 to 12 cm including the petiole and the width, measured at the widest point, is 3 cm in average. Leaf shape is subulate, the tip is acuminate, the base is acute, the venation is netted and the surface is glabrous ( FIG. 5 ). Leaf Margins: Leaf margin is serrulate and at the tip of each indentation there is a protrusion that resembles a small spine with a red color (2.5R-4/8 set by Munsell Color Chart for Plant Tissues standards). Leaf color, in mid July, is green yellow (5GY 4-4 set by Munsell Color Chart for Plant Tissues standards). The leaf petiole is of average size. The color of the leaf petiole is green yellow (5GY 6-4 set by Munsell Color Chart for Plant Tissues standards). The length of the petiole is 10 mm and the thickness is 1 mm. The leaf petioles are glabrous. There are no stipules at the base of the petiole. There are an average of two reniform shaped leaf glands per leaf located on the petiole portion closest to the leaf blade. The color of the leaf glands is red (2.5 R 5/4 set by Munsell Color Chart for Plant Tissues standards).
Fruit:
Fruit.— The fruit is free stone. They ripen in the last week of July to the first week of August in Davis, Calif. Their surface, resembling a typical peach, is pubescent. Their shape is round with length equal to the width ranging from 50 to 60 mm. The tree produces an abundance of fruits and may break branches if not thinned. The color of fruit skin is green yellow (GY 21-2 set by Munsell Color Chart for Plant Tissues standards) — ( FIG. 6 ). The color of the fruit when the fruit is between mature and ripe is yellow green (22-1 set by Munsell Color Chart for Plant Tissues standards). The color of the flesh adjacent to the seed is reddish (2.5R-5/10 set by Munsell Color Chart for Plant Tissues standards).
Seed:
Seed.— The seed (pit), resembling a typical peach seed, is ovate in shape with protrusion at the tip and deep grooves on the surface. The length, including the protrusion, is 30 to 35mm and the width is 20 to 25 mm. The color is yellow red (7.5 YR 4-4 set by Munsell Color Chart for Plant Tissues standards) — ( FIG. 6 ). The kernel of the seed is ovate with a length of 15 mm and a width of 12 mm. The color of the kernel is yellow red (5 YR 6/8). Resembling a typical peach seed kernel, it is bitter in taste.
Floral description:
Flower buds.— The flower buds are medium in size, 5 mm in length and 3.5 mm in width when first swelling ( FIG. 7 ). One flower bud is usually born on each side of a vegetative bud. One vegetative bud is born on each node of one-year old wood. The flower buds are conic in form and relatively plump. The buds are hardy under typical Sacramento Valley, Calif. climatic conditions. Bud scales are red (2.5R-4-4) set by Munsell Color Chart for Plant Tissues standards ( FIG. 7 ). The surfaces of the buds are heavily pubescent on the margins of the bud scales and gradually less in pubescence towards the center of the bud scales. The center of the bud scales is slightly pubescent. Blooming time.— The time of the bloom is early in relation to standard commercial peach cultivars grown in the Sacramento Valley, Calif. climatic conditions. Average date of bloom is February 19. Average date of full bloom is March 1st. The start of vegetative bud break coincides with full bloom. Flower size.— Average flower diameter, in a fully expanded condition, is 40 mm ( FIG. 7 ). Bloom quality.— Bloom quantity is heavy when compared with standard commercial peach cultivars grown in the Sacramento Valley, Calif. climatic conditions. The number of flower buds per node ranges from 1 to 3 with an average of two being most common. Many of the flower buds are retained on the tree to full bloom. Flower petals.— The number of the petals per flower is five. The length of the flower petal is 20-25 mm and the width is 15-17 mm, in a fully expanded flower ( FIG. 5 ). The shape of the petals is orbicular with margins that are entire. Each of the petals has nine main ribs palmate with net arranged veins. The petal color is pink (2.5R-9/3 set by Munsell Color Chart for Plant Tissues standards), with color intensifying (2.5R-8/5) towards the base. Flower pedicels.— The length and the width of each of the flower pedicel and calyx, in a fully expanded flower, is 1 mm each. The color of the pedicel and the calyx is green yellow (2.5GY-7/8 set by Nickerson Color Fan standards) — ( FIG. 7 ). The surface of the pedicel is glabrous. Sepals.— The number of the sepals is five. The surfaces of the sepals are heavily pubescent on the margins of the bud scales and gradually less in pubescence towards the center of the bud scales. The center of the bud scales is slightly pubescent. The form is conic with a round apex. The width of the upper part, measured at the middle point, is 4 mm; the lower part is 2 mm. The color of the sepals, in a fully expanded flower, is red (2.5R-4/6 set by Munsell Color Chart for Plant Tissues standards) — ( FIG. 7 ). The lower section of the sepals, from the early stages of the popcorn state to fully expanded flowers, has red dots. The color of the dots is the same as the sepals at the fully expanded state of the flower. Anthers and pollen.— The size is of the anthers is average. During the pop-corn stage of flower bud development, the color is red (5R-5/10 set by Munsell Color Chart for Plant Tissues standards) dorsally and around the edges ventrally ( FIG. 7 ). Pollen is viable and medium in availability. Pollen color is yellow (2.5Y-8/12 set by Munsell Color Chart for Plant Tissues standards). Stamens.— The average number of stamens is 40. Stamen length is variable, from 11 to 19 mm in a fully expanded flower. Color of stamen is red (2.5R-8/4 set by Munsell Color Chart for Plant Tissues standards) — ( FIG. 7 ). Pistil.— The pistil length is 18 to 20 mm. The pubescent ovary is 2 mm in length with a width of 1 mm; the style length is 18 mm with 0.3 mm width; and the stigma's length is 0.5 mm and with a width of 0.2 mm. The color of the style is yellow (7.5Y-9/8 — set by Munsell Color Chart for Plant Tissues standards). The color of the ovary, after removing the pubescence, is green yellow (2.5GY-6/8 set by Munsell Color Chart for Plant Tissues standards).
Summary
[0087] The new ‘HBOK 50’ rootstock, a hybrid between two peach parents, is useful as a commercial under-stock for peach and nectarine and perhaps, almond cultivars. The stock has been successfully propagated clonally by leafy cuttings and tissue culture. This rootstock imparts significant vigor control to the scion cultivar that is propagated on top of it. This rootstock produces very few root suckers, its anchorage is good and it is resistant to root-knot nematode. Utilization of adapted growth controlling rootstocks in commercial orchard situations reduces the height of the tree and the amount of wood pruned in the winter and summer, without compromising the quality of the fruit. This in turn increases the efficiency of various cultural operations such as pruning, thinning and harvesting by reducing the need for workers in the field to use tall ladders when carrying out these operations.
[0088] The following references are incorporated by reference for the purpose of providing further comparative data related to the claimed plant material.
Bliss, F. A., A. A. Almehdi, A. M. Dandekar, P. L. Schuerman and N. Bellaloui. 1999. Crown gall resistance in accessions of 20 Prunus species. HortScience 34(2):326-330. DeJong, T., A. Almehdi, S. Johnson and K. Day. 2005. Improved rootstocks for peach and Nectarine. California Tree Fruit Agreement, Annual Report-2005. 20 pp. DeJong, T., A. Almehdi, S. Johnson and K. Day. 2006. Improved rootstocks for peach and Nectarine. California Tree Fruit Agreement, Annual Report-2006. 18 pp. DeJong, T., A. Almehdi, S. Johnson and K. Day. 2007. Improved rootstocks for peach and Nectarine. California Tree Fruit Agreement, Annual Report-2007. 19 pp. DeJong, T., A. Almehdi, S. Johnson and K. Day. 2007. Improved rootstocks for peach and Nectarine. California Tree Fruit Agreement, Annual Report-2008. 19 pp. DeJong, T., A. Almehdi, J. Grant and R. Duncan. 2004. Evaluation of rootstocks for tolerance to bacterial canker and orchard replant conditions. Cling Peach Annual Report— 2004 . 11 pp. DeJong, T., A. Almehdi, J. Grant and R. Duncan. 2005. Evaluation of rootstocks for tolerance to bacterial canker and orchard replant conditions. Cling Peach Annual Report—2005. 16 pp. DeJong, T., A. Almehdi, J. Grant and R. Duncan. 2006. Evaluation of rootstocks for tolerance to bacterial canker and orchard replant conditions. Cling Peach Annual Report—2006. 15 pp. Dirlewanger, E., E. Graziano, T. Joobeur, F. Garriga-Caldere, P. Cosson, W. Howard and P. Arús. 2004. Comparative mapping and marker assisted selection in Rosaceae fruit crops. Proc. Natl. Acad. Sci. USA 101:9891-9896. Foolad, M. R., S. Arulsekar, V. Becerra, F. A. Bliss. 1995. A genetic map of Prunus based on an interspecific cross between peach and almond. Theor. Appl. Genet. 91:262-269. Gillen, Anne M. 2001. Developing a Size-controlling and Root-knot Nematode Resistant Peach [ Prunus persica (L.) Batsch] Rootstock. Ph.D. Dissertation, University of California, Davis. 237 pp. Gillen, Anne M. and F. A. Bliss. 2005. Identification and mapping of markers linked to the Mi gene for root-knot resistance in peach. J. Amer. Soc. Hort. Sci. 130:24-33. Howad, W., T. Yamamoto, E. Dirlewanger, R. Testolin, P. Cosson, G. Cipriani, A. J. Monforte, L. Georgi, A. G. Abbott. 2005. Mapping with a few plants: using selective mapping for microsatellite saturation of the Prunus reference map. Genetics 171:1305-1309. McKenry, M. 12-30-2007. A greater number of rootstock choices can provide a partial alternative to methyl bromide fumigation. A Report to the California Tree Fruit Agreement. McKenry, M. 2008. Development of nematode/rootstock profiles for 40 rootstocks with the potential to be alternatives to ‘Nemaguard’. California Almond Board, 2007 Conference Proceedings. Ogundiwin, E. A., C. P. Peace, T. M. Gradziel, D. E. Parfitt, F. A. Bliss and C. H. Crisosto. 2009. A fruit quality gene map of Prunus. BMC Genomics (In review). Sherman. W. B., Paul M. Lyrene and P. E. Hansche. 1981. Seedling Peach Rootstocks Resistant to Root-knot Nematodes. HortScience 16:523-524. Westwood, M. N. 1978. Temperate-Zone Pomology. Freeman, New York, N.Y.
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A new and distinct variety of peach rootstock denominated ‘HBOK 50’ is described. The ‘HBOK 50’ peach rootstock offers size control ability, root knot nematode resistance, less wood from dormant and summer pruning, and production of fewer root suckers. ‘HBOK 50’ has contributed to size reduction of compound trees when it is used as a clonally-produced rootstock with the fresh market peach “O'Henry”. No evidence of graft incompatibility or other abnormalities have been noted in such circumstances. Fruit on compound trees with ‘HBOK 50’ rootstocks is either similar in size or smaller than ‘Nemaguard’. The ‘HBOK 50’ rootstock displays root knot nematode resistance levels similar to ‘Nemaguard’ and more resistant than ‘Lovell’.
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CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to U.S. Provisional Patent Application Ser. No. 61/742,135, filed Aug. 3, 2012, which application is incorporated herein in its entirety by this reference.
FIELD OF THE INVENTION
[0002] This invention relates generally to carpet tiles and other textile face modular flooring and to methods of designing modular flooring having striped patterns and installations of such flooring that mimics the appearance of broadloom carpet.
BACKGROUND OF THE INVENTION
[0003] In part for ease of installation, modular carpet has traditionally been installed in aligned rows and columns of square modules or “tiles,” with the edges of each tile aligned with the edges of adjacent tiles (“conventional carpet tile installation method”). Conventional carpet tile has also historically been a product that sought to mimic the appearance of seamless broadloom carpet and to hide or at least de-emphasize the fact that the product was modular. See, for instance, U.S. Pat. No. 6,908,656, which is incorporated herein in its entirety by reference.
[0004] Textile face modular flooring designers have sometimes designed flooring and flooring installations that do not seek to mask, but rather emphasize, the modularity of the flooring. For instance, modules can be installed “quarter-turned” with each tile position rotated 90° relative to each adjacent tile. In other instances, module edges are emphasized to achieve an installation appearance similar to that of ceramic tile separated by grout.
[0005] There continues, however, to be substantial demand for flooring designs that do not visually emphasize the modularity of flooring components and instead appear to have a design that spans the entire flooring installation or part of the flooring installation rather than appearing to be confined to individual modules.
[0006] There likewise is continuing demand for carpet tiles capable of installation in ways that present new visual designs and patterns.
[0007] Carpet tile and other textile face modular flooring has to be highly uniform in size and shape and has to have edge structures that present a uniform floor covering when edges of adjacent tiles are abutting. These requirements typically make it a practical necessity for such products to be produced by forming a web of material that is at least somewhat wider than the width of one flooring module, and preferably a bit wider than some multiple of modules, and then cutting modules from that web. For instance, carpet tiles are typically produced by manufacturing a web a bit more than six feet wide and then cutting from it tiles that are eighteen inches square, or by manufacturing a web a bit more than two meters wide and then cutting from it tiles that are one-half meter square. In each case, four tiles can be obtained across the web. While it is relatively easy to cut modules from such a web that have a desired size with a high level of accuracy, it is difficult to position the longitudinal cuts or module separation lines accurately with respect to predetermined positions on the web. It is likewise difficult to position the transverse cuts or separation lines accurately with respect to predetermined positions on the web, at least without substantial material waste.
[0008] Some design types present particular problems for use on modular flooring. One such difficult design type is parallel stripes. (As used in this application and patent, “stripes” are visibly different regions of the flooring face having portions of relatively uniform width that typically are significantly longer than wide.) To ensure a fluid appearance in a flooring installation, the tiles cut from a web having uninterrupted stripes extending along its length obviously must be oriented so that all of the stripes of the tiles are oriented in the same direction. However, this alone will not achieve an aesthetically desirable installation appearance.
[0009] First, attention has to be paid to the appearance at the places where side-by-side tiles are abutting in an installation so that there is not an out-of-place or odd appearing stripe at that location. Additionally, attention may be drawn to the place where top-to-bottom tile abutment occurs, i.e., where the ends of stripes on one tile meet the ends of stripes on another tile.
[0010] One could imagine a design having uniform-width, parallel stripes that fall in precisely the same locations on each tile. It would then be possible to position such tiles in the same orientation on a floor to produce a uniform pattern of uninterrupted, uniform, parallel stripes across a room. Such carpet tiles would be very difficult to produce, however, using conventional production techniques where a carpet web is produced and then cut into tiles, because it is difficult to achieve identical tiles.
[0011] One reason for this is that it is difficult to locate the cuts that separate the web into tiles precisely in predetermined locations. This will result in different width stripes at tiles edges (where the stripes are of uniform width on the carpet web). Additionally, unless tiles are positioned so that the stripes on one tile are precisely aligned with the stripes on an adjacent tile, the appearance of continuous stripes on the web will not be reproduced on the floor. Such precise alignment is difficult to do unless the tiles are reassembled exactly as they came from the web. It is unlikely that stripes will align from one tile to the next because, among other reasons, of variation in the location of longitudinal cuts on the web. Imprecise cutting can result in stripes of a tile appearing offset from stripes of adjacent tiles, thereby betraying seams and ruining the appearance of continuous stripes in the flooring installation. Additionally, as noted above, the position of the longitudinal cuts relative to the stripes into which or next to which they fall can create a stripe that appears to be wider or narrower than those in the design (except, of course, where the modules are assembled on the floor in the same side-by-side location they had in the web and the split stripe is re-assembled). Given the necessity but difficulty of attaining cutting precision with conventional striped designs, flexibility in placement of the tiles having a conventional striped pattern of equal-width, continuous stripes is severely limited.
[0012] U.S. Pat. No. 7,297,385 (incorporated in its entirety herein by this reference) addressed the need for modular flooring design and production techniques that enable the creation of flooring designs having parallel stripes notwithstanding the above-described and other constraints of conventional modular carpet construction and installation. It did so by providing a broadloom carpet web and a method of forming a carpet web having a striped pattern and color scheme that permits carpet tiles cut from the web to be installed without regard to relative tile positions and without visibly disrupting the pattern, but rather maintaining the appearance of a broadloom web. This was accomplished, in part, by introducing in the web design, and therefore in some of the tiles cut from the web, “longitudinal discontinuities” that mask or take attention away from longitudinal discontinuities that typically occur at top-to-bottom tile interfaces. (“Longitudinal discontinuities” are places in the flooring where one or more stripes or other visible elements of the flooring end and other stripes extending in the same direction or other visible elements begin.) The U.S. Pat. No. 7,297,385 patent techniques produce attractive, distinctive carpet tile installations that exhibit prominently numerous longitudinal discontinuities.
SUMMARY OF THE INVENTION
[0013] The terms “invention,” “the invention,” “this invention” and “the present invention” used in this patent are intended to refer broadly to all of the subject matter of this patent and the patent claims below. Statements containing these terms should be understood not to limit the subject matter described herein or to limit the meaning or scope of the patent claims below. Embodiments of the invention covered by this patent are defined by the claims below, not this summary. This summary is a high-level overview of various aspects of the invention and introduces some of the concepts that are further described in the Detailed Description section below. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used in isolation to determine the scope of the claimed subject matter. The subject matter should be understood by reference to appropriate portions of the entire specification of this patent, any or all drawings and each claim.
[0014] The broadloom-like appearance of installations of the flooring of this invention is achieved by producing carpet modules in certain sizes and or proportions (as further described below) from a carpet web in which multiple yarn heights, types, colors or other properties produce narrow stripes or rows of yarn that differ in a random-looking way in color, yarn type, height, width or length or a combination of some or all of those or other attributes.
[0015] Optionally, the web may have variations in “background” and “foreground” yarn color, height and pile (e.g., loop or cut pile) according to a separate patchy, cloud-like or organic-looking pattern or other patterns. After the web is manufactured and backing is applied, it is cut into rectangular modules or “planks” typically (but not necessarily) approximately one-fourth meter wide and one meter long (or approximately one-fourth yard wide and one yard long), and the carpet modules are installed, usually aligned longitudinally but staggered laterally.
[0016] Modular carpet installations aligned in one direction (e.g., up and down the floor) and staggered at right angles to that first direction (e.g., laterally) may be referred to as “ashlar” installations. Installations aligned across a floor and staggered up and down are sometimes also referred to as “ashlar” installations and other times are referred to as “brick” or “brick ashlar” installations. “Ashlar” as used in this application and patent means modules installed aligned in a first direction and staggered in a second direction perpendicular to the first direction.
[0017] The absence of lateral alignment in modular flooring installations of this invention means that longitudinal visual discontinuities in the installation will be relatively narrow and unobtrusive. Significantly, the visual discontinuities for rectangular carpet modules of the above-described dimensions will be, at most, only one-half as wide as would be the case with conventional square tiles because the modules are only half as wide. The modest width of visual discontinuities helps to mask the fact that the flooring is modular. Furthermore, while these rectangular carpet modules will have twice as much length of longitudinal “seams” where two modules abut side to side as compared to square carpet tiles one-half as long as these rectangular modules, the same installation of rectangular carpet modules will have about one-half as much length of perpendicular (end to end) “seams” where two modules abut end to end. The combination of shorter and fewer end to end seams facilitates creation of broadloom-like appearance in flooring installations of the rectangular modules of this invention. This benefit would be even greater if the rectangular modules are made longer and if they are made narrower or both. Thus, the modules could be as little as about 2 to 1 length to width and as great as about 10 to 1 length to width, but there are practical limits on length and width of modules, which limits may be different in different situations depending on such variables as manufacturing technique, installation conditions, room size and many other variables.
[0018] In many fields of human endeavor scale is not particularly important because, among other possibilities, changes in scale will not change function. There are, on the other hand, numerous situations where scale is significant. In some instances, human scale matters very much. Human vision is limited by the characteristics of the human eye and brain. Close objects can be too small for a human to see without magnification, just as larger objects may be too distant for humans to see without magnification. Another example also has to do with vision. Humans can see certain wavelengths of light but not all wavelengths and not as broad a range of wavelengths as some animals.
[0019] Most floorcoverings are seen by humans from at a range of distances beginning at about four feet, the typical minimum distance of adult human eyes above the floor of a standing person looking down at a floor. Interior building spaces are almost all designed to “human scale” with similar size rooms, similar width corridors and the like. Even in relatively uncommon interior spaces that are dramatically larger than typical spaces, the heights of humans and the constraints of their visual abilities cause them to see clearly about the same quantities of floor space from about the same distances and with about the same visual acuity.
[0020] Similarly, “carpet scale” constraints are associated with carpet and carpet tile textile floorcoverings. While versatile, commercially practical weaving and tufting techniques all utilize closely similar materials (mostly nylon fiber on carpet faces), the same relatively small range of sizes of fibers and yarns, the same small range of lengths of yarns protruding on the carpet face, the same small range of densities of yarns and the essentially the same palate of colors.
[0021] Carpet can be produced in very large sizes and much smaller sizes and has been so produced. Carpet tiles have long been produced in square sizes, but only sizes ranging between about one foot square up to one yard or one meter square (i.e., in a ratio of side lengths of 1:1) are commercially practical and desirable. Carpet tiles have previously been produced in rectangles such as ½ meter by 1 meter or 18 inches by 36 inches (i.e., in a ratio of side lengths of 2:1). The inventor of this patent has discovered that smaller, proportionately narrower rectangles of carpet tile—on the order of about ¼ meter (25 centimeters) by about 1 meter (100 centimeters) (or about 9 inches by about 36 inches) (i.e., in a ratio of side lengths of 1:4) and with appropriate face yarns and patterns—enable:
a. installations having remarkable uniform, broadloom-like appearance without visible seams and b. a wide variety of other visually attractive and visually functional installation designs.
[0024] These capabilities utilizing carpet “planks” about ¼ meter by about 1 meter seem to function as they do because of, and to reflect, human scale, carpet scale and visual diversity considerations.
[0025] One aspect of the greater visual diversity and better seam-hiding that can be achieved with carpet planks of this size can be understood by imagining a typical human-scale floor that is five meters by five meters square (around 16 feet by 16 feet square). Such a floor is fully covered by 10×10=100 one-half meter square tiles with 9×5=45 meters of seams running in each of the up and down and across directions. By contrast, such a floor is fully covered by 20×5=100 one-fourth meter by one meter plank-shaped tiles, with only 3×5=15 meters of across the web seams. Thus, with the planks, there is only one third as much cross-web seam to hide. This facilitates achieving a continuous appearance using certain stripe patterns in installations of closely similar tiles.
[0026] Such carpet planks are very versatile in other installation patterns using planks that are not all alike, and that are not necessarily installed with staggered plank ends, including installations of planks having different colors, different tufting patterns, different yarns, different yarn heights and other differences in appearance. Such planks can also be used with tiles of different sizes and shapes, including, for instance, tiles that are one-fourth meter square.
[0027] Now consider a commercial space corridor about two meters wide. With one-half meter square tiles, only 4 tiles can be positioned across the width of the corridor. By contrast, with one-fourth meter by one meter tiles positioned longitudinally, 8 tiles can be positioned across the width of the corridor facilitating dramatically different corridor floor patterns.
[0028] As yet another example, herringbone patterns of one-fourth meter by one meter planks (side ration of 1:4) are dramatically different in appearance from herringbone patterns of one-half meter by one meter or one meter by two meter tiles (side ration of 1:2) because of human scale and carpet scale considerations as well as the difference in the ratio of side lengths.
BRIEF DESCRIPTION OF THE FIGURES
[0029] This patent or application file contains at least one color photograph. Copies of this patent or patent application publication with color photograph(s) will be provided by the Office upon request and payment of the necessary fee.
[0030] Illustrative embodiments of the present invention are described in detail below with reference to the following drawing figures:
[0031] FIG. 1 is a perspective view of a modular carpet installation of this invention.
[0032] FIG. 2 depicts a pattern used to produce a tufted web from which the carpet modules or planks depicted in FIG. 1 were made.
[0033] FIGS. 3 , 4 , 5 and 6 depict top or plan views of assemblies of carpet modules having the pattern depicted in FIGS. 1 and 2 but with different sizes and arrangements as follows:
[0034] FIG. 3 depicts ¼ meter by 1 meter modules in an ashlar installation.
[0035] FIG. 4 depicts ¼ meter by 1 meter modules in a monolithic installation.
[0036] FIG. 5 depicts ½ meter by ½ meter tiles in an ashlar installation.
[0037] FIG. 6 depicts ½ meter by ½ meter tiles in a monolithic installation.
[0038] FIGS. 7 , 8 , 9 and 10 are the same as FIGS. 3 , 4 , 5 and 6 , respectively, except that broken lines have been added at the locations of the module edges to make the individual modules easier to see.
[0039] FIG. 11 is a schematic diagram depicting an installation of carpet modules with adhesive-bearing connectors located under approximately one half of module corner locations.
[0040] FIG. 12 is another schematic diagram depicting an installation of carpet planks with adhesive-bearing connectors located under all module corner locations.
[0041] FIGS. 13A and 13B depict monolithic and ashlar assemblies of square modules, respectively, with regular or regimented stripes; FIGS. 13C and 13D depict monolithic and ashlar assemblies of rectangular carpet modules, respectively, with a random-looking stripe pattern.
[0042] FIGS. 14 A and 14 B depict monolithic and ashlar assemblies of square modules, respectively, with a random-looking stripe pattern; FIGS. 14C and 14D depict monolithic and ashlar assemblies of rectangular modules, respectively, with a random-looking stripe pattern.
[0043] FIGS. 15-100 depict additional carpet tiles, planks and other modules and additional assemblies of planks and other modules in accordance with this invention.
DETAILED DESCRIPTION
[0044] The subject matter of embodiments of the present invention is described here with specificity to meet statutory requirements, but this description is not necessarily intended to limit the scope of the claims. The claimed subject matter may be embodied in other ways, may include different elements or steps, and may be used in conjunction with other existing or future technologies. This description should not be interpreted as implying any particular order or arrangement among or between various steps or elements except when the order of individual steps or arrangement of elements is explicitly described.
[0045] FIG. 1 depicts an installation 10 of the carpet modules or planks 12 of this invention that exhibits a broadloom-like appearance. FIG. 2 depicts a pattern 14 usable to produce a carpet web from which the carpet planks 12 are produced.
[0046] The broadloom-like appearance of installations of the flooring of this invention, such as installation 10 , is achieved by producing carpet modules having at least two characteristics and installing them in an arrangement that facilitates a continuous appearance. This can often be achieved with an ashlar or similar arrangement with staggered shorter edges, but other arrangements will be acceptable in some instances. First, a carpet web from which the modules will be produced having narrow stripes or striations 15 , preferably in a random-looking pattern. An example of a random-looking pattern 14 having stripes or striations 15 may be seen in FIG. 2 . Such stripes or striations 15 can be created in numerous ways, including printing a fabric web or creating a fabric web with stripes or striations 15 by tufting in different colors or producing other variations in yarn height, type, pile (e.g., loop or cut pile). Second, the carpet modules are manufactured in rectangles approximately ¼ meter wide by one meter long (approximately 25 centimeters by 100 centimeters) or approximately ¼ yard wide by one yard long (approximately 9 inches by 36 inches) with longer module edges parallel to the stripes or striations 15 . The rectangular modules are preferably installed in an ashlar arrangement such as that depicted in FIGS. 1 , 3 , 7 , 11 and 12 in which the rectangular modules are aligned end to end but not side to side (the longer edges are aligned with the longer edges of modules abutting the shorter edges of each module but the shorter edges are not aligned with like edges of tiles abutting the longer edges).
[0047] The appearance of an installation of such modules 12 can be further enhanced by incorporating patchy, cloud-like or organic-looking elements in the pattern, such as elements 17 , 19 and 21 in pattern 14 in FIG. 2 , but a broadloom-like appearance may be achieved without such elements 17 , 19 and 21 and with other design elements. Likewise many different patterns of stripes or striations may be used to produce the modules of this invention.
[0048] The stripes or striations 15 significantly reduce the prominence of the longer module 12 edges 23 (See FIG. 7 ) because they lie parallel to the striations 15 and are essentially buried between the striations 15 or otherwise are not visually prominent. Narrow strips avoid the risk of an “out-of-place” narrow strip that could appear at the edge of a module having a pattern with only broad stripes. Use of a random-looking pattern of narrow stripes or striations 15 contributes to a continuous, broadloom-like appearance in an installation of such modules 12 for reasons that can be appreciated by comparing the appearance of monolithic and ashlar assemblies of square and rectangular modules having either (1) a “regimented” or regular stripe pattern or (2) a random-looking stripe pattern.
[0049] FIGS. 13A and 13B depict monolithic and ashlar assemblies of square modules 30 , respectively, with regular or regimented stripes formed by utilizing a regular or regimented thread-up like AABBCCDD . . . etc. FIGS. 13C and 13D depict monolithic and ashlar assemblies of rectangular modules 32 , respectively, with a regular or regimented striped formed by utilizing a regular or regimented thread-up.
[0050] Because wider stripes 34 sometimes appear where stripes on side-to-side abutting square modules 30 “combine” in the assembly, but only at places where tiles abut, such wider stripes 34 are visually prominent, as is clear in FIGS. 13A and 13B . Likewise, the same phenomenon is present in the assemblies of rectangular tiles 36 in FIGS. 13C and 13D , where such visually prominent wide stripes 38 are marked.
[0051] FIGS. 14 A and 14 B depict monolithic and ashlar assemblies of square modules 40 , respectively, with a random-looking stripe pattern produced by using a random thread-up in which the stripes have different widths and or different colors or types of yarns are utilized in a random-looking sequence that was not have a visually identifiable sequence. FIGS. 14C and 14 D depict monolithic and ashlar assemblies of rectangular modules 42 , respectively, with the same random-looking stripe pattern as is used in modules 40 . The random-looking stripe pattern includes stripes of various widths, including wide stripes 44 and narrow stripes 46 . Because wide stripes 44 appear elsewhere in the modules, the occurrence of wide stripes at abutting module edges, because both edges carry part of a stripe having the same appearance, does not look out of place or call attention to the location where the modules 40 or 42 abut. This contributes to camouflage of tile “seams” parallel to the stripes 44 and 46 .
[0052] Focusing again on FIGS. 3 , 4 , 7 and 8 , the module 12 shorter edges 25 are more easily seen than longer edges 23 , but the shorter edges 25 in FIGS. 3 and 7 are not visually prominent because they are not aligned with the shorter edges 25 of abutting modules (as is the case in FIGS. 4 and 8 ).
[0053] In the case of a rectangular module four times as long as it is wide (like modules 12 in FIGS. 7 and 8 ), there is only one-half as much length of such shorter edges 25 than would be found in an installation of square modules that are twice as wide and one-half as long. Modules even longer than about one yard or one meter would further reduce the quantity of shorter edges in a given installation, but significantly longer modules present manufacturing, shipping, installation and other issues that make modules 12 in at least approximately the described dimensions very practical while providing a good balance of visual and other properties.
[0054] In order to further illustrate the benefit of staggered installation of the modules 12 , FIGS. 4 and 8 depict modules 12 that are not staggered but are instead installed with both longer and shorter edges aligned. The horizontal, aligned shorter edges marked in FIG. 8 are relatively easily seen without marking in FIG. 4 .
[0055] FIGS. 5 and 9 depict an ashlar configuration of square tiles 13 (and half-tiles 13 A in FIG. 9 ) using the pattern of FIG. 2 . This ashlar configuration is superior to the monolithic installation of the same square tiles 13 depicted in FIGS. 6 and 10 . However, all of the installations of square tiles 13 and 13 A in FIGS. 5 , 6 9 and 10 have twice as much tile edge 17 perpendicular to the stripes 15 as do assemblies of rectangular modules 12 (where the rectangles are four times as long as they are wide). Such tile edges 17 are easily seen in the monolithic installations of FIGS. 6 and 10 (where they are aligned) and are undesirably evident in the ashlar installations of FIGS. 5 and 9 .
[0056] A carpet web usable to make the carpet planks or modules of this invention may be tufted using conventional or computer controlled tufting machines able to produce patterns containing the stripes or striations 15 described above with appropriate yarn thread ups.
[0057] Installation of the carpet planks or modules 12 of this invention in a room may be accomplished by snapping a chalk line on the floor of the room dividing the room approximately in half. The line typically will be (but need not necessarily be) parallel to least one wall in the room. A line of carpet modules 12 of this invention is then laid on the floor end to end and aligned with the chalk line on the floor. A second line of modules 12 may then be installed beside the first line but with the end to end seams of the second row staggered relative to the first line. Such staggering can be done with the seams of one row of modules 12 at the mid-point of a contiguous row of modules 12 , but the seams may be staggered in different relative positions, such as is achieved by staggering adjacent rows offset by one third of module length. Moreover, alternate rows need not be aligned with each other. When alternating lines of modules 12 or every third line of modules 12 are to be aligned, it may be desirable to snap a second and perhaps a third and fourth chalk line perpendicular to the first chalk line so that ends of tiles in alternating rows are aligned with one of the second or third or fourth (perpendicular) chalk lines.
[0058] The modules 12 may be “free laid” without adhesive or any other attachment to the floor or each other. The modules 12 may also be glued down with appropriate conventional adhesive spread on the floor, the undersides of the tiles or both in advance of installation. The modules 12 may also be installed utilizing adhesive-bearing connectors such as Interface Flooring's TacTiles® adhesive connectors, typically by locating such a connector 26 on the undersides of the modules 12 at every pair of corners 28 (see FIG. 12 ) or every other pair of corners 28 (see FIG. 11 ). Usable adhesive connectors are disclosed, among other places, in U.S. Pat. Nos. 7,721,502, 7,464,510 and 8,381,473 B2, all of which are incorporated herein in their entirety by reference. ( FIGS. 3 and 7 and the schematic depictions of FIGS. 11 and 12 include full modules 12 and partial modules 12 A. Partial modules 12 A would typically by cut from full modules 12 for use at the edge of a room where a floor encounters a wall.) Typically the connectors 26 will be attached to and joining two module or plank corners 28 and the adjacent third plank or module 12 . Installation with TacTiles® or similar connectors can be done with the connectors inserted as the flooring modules 12 are laid. Connectors 26 can be used at all module 12 corners 28 , at one half of the module corners 28 or in any other appropriate configuration. The sequence of installation of connectors can vary. For instance, the following two sequences of steps are two method that may be used to install floor modules 12 with connectors 26 at only half of all tile corners 28 .
[0059] A first sequence of steps for rectangular carpet module installation with adhesive-bearing connectors at about half of all module corners includes:
1. positioning a first module on the floor, 2. lifting a corner of the first module and inserting approximately one-fourth of a first adhesive-bearing connector under the lifted module corner, 3. pressing the lifted module corner down on the first connector, 4. laying a second module abutting and aligned end to end with the first module and pressing a corner of the second module onto the first connector, 5. laying a third module abutting and side to side with the first and second modules 12 and on top of the uncovered portion of the first connector, 6. lifting a corner of the second module and inserting approximately one-fourth of a second connector under the lifted module corner, 7. pressing the second tile lifted module corner down on the second connector, 8. repeating steps 4 and 5 with fourth and fifth modules 12 as needed until two side-by-side lines of modules 12 are positioned on the floor, 9. lifting the adjacent corners of the third and fifth modules 12 remote from the second module, inserting approximately one-half of a third connector under the third and fifth modules 12 and pressing those lifted corners down on the third connector, 10. on the side of the row remote from the first row of modules 12 , lifting the adjacent corners of each pair of modules 12 in the second row of modules 12 and inserting approximately one-half of a connector and pressing the module corners down on the connector until all second line module pairs are so connected, 11. repeating step 9 until a third line of modules 12 has been installed, and 12. positioning a fourth line of modules 12 adjacent to the third line of modules 12 abutting and staggered relative to the third line of modules 12 and repeating steps 9, 10 and 11 until all modules 12 required have been installed.
[0072] A second, alternative sequence of steps for floor module installation with connectors at about half of all module corners includes:
1. positioning a first module on the floor, 2. lifting a corner of the first module and inserting approximately one-fourth of a first connector under the lifted module corner, 3. pressing the lifted module corner down on the first connector, 4. laying a second module abutting and aligned end to end with the first module and pressing a corner of the second module onto the first connector, 5. laying a third module abutting and side to side with the first and second modules 12 and on top of the uncovered portion of the first connector, 6. lifting a corner of the second module and inserting approximately one-fourth of a second connector under the lifted module corner, 7. laying a fourth module abutting and aligned end to end with the second module and pressing and pressing fourth module onto the second connector, 8. lifting a corner of the third module remote from the first module and inserting approximately one-fourth of a third connector under the lifted module corner, 9. pressing the third tile lifted module corner down on the third connector, 10. laying a fifth module abutting and aligned end to end with the third module and on top of portions of the second and third connectors, and 11. repeating appropriate ones of the preceding steps with additional modules 12 and connectors until all modules 12 needed have been laid.
[0084] The carpet modules 12 of this invention can also be installed in the same general manner as described above but with placement of a connector at all tile corners or at any fraction of all of the tile corner locations. Regardless of the number of connectors used for an installation of carpet modules 12 , the sequence of steps can be varied for ease, convenience and otherwise as desired in a particular installation.
[0085] The modules 12 of this invention may be produced by first producing a wider carpet web having a pattern exhibiting the characteristics described herein and then cutting the web into modules 12 in the conventional ways that tiles are typically cut from a carpet web produced for that purpose. The web design can be rendered in any conventional manner, such as tufting or weaving a web with a desired pattern or by printing a tufted, woven or other web. The techniques of this invention are particularly well suited, however, for production by rendering the pattern through tufting with yarn pre-dyed in suitable colors.
[0086] Appropriate backing like that used for conventional square carpet tiles is applied to the carpet web before it is cut into modules 12 in order to impart appropriate stiffness, stability and other needed properties.
[0087] Different arrangements are possible for the components and steps shown in the drawings or described above, and components and steps not shown or described can also be used. Similarly, some features and subcombinations are useful and may be employed without reference to other features and subcombinations. Embodiments of the invention have been described for illustrative and not restrictive purposes, and alternative embodiments will become apparent to readers of this patent. Accordingly, the present invention is not limited to the embodiments described above or depicted in the drawings, and various embodiments and modifications can be made without departing from the scope of the claims below.
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Rectangular carpet modules or “planks” and installation of such planks having the continuous appearance of broadloom carpet or a wide variety of other effective, human scale designs. “Planks” sized approximately ¼ meter (25 cm) by 1 meter (100 cm) (or approximately 9 inches by 36 inches) are particularly effective.
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FIELD
The present invention relates to tarpaulin cover systems, and in particular to a tensioning and locking device for producing and maintaining a sufficient amount of tension throughout a tarp cover.
BACKGROUND
Tarpaulin cover systems are commonly used to cover cargo being transported by truck, train, ship, and other vehicles. It is often desirable to cover cargo to protect it from the elements. It may also be desirable to shield the cargo from view.
Cargo that is to be transported may be positioned directly on a vehicle, such as on a truck or trailer bed, or on a rail car. Alternatively, the cargo may first be positioned on a shipping base, such as a shipping or cargo pallet. The shipping base may then be placed on or in the vehicle for transport. The term “base structure” will hereinafter be used to refer to both vehicles and shipping bases. In either instance, it is often desirable to cover the cargo being transported.
Tarpaulin cover systems are particularly common in the trucking industry. One type of shipping configuration comprises a fully enclosed and rigid cargo area. Most of these cargo areas have one or more doors in the enclosure for loading and unloading the cargo. In particular, many trucks or trailers have an opening at their rear end for this purpose. However, such fully enclosed and permanent cargo areas are not well suited for the loading and unloading of certain types of cargo. For example, very large or very heavy items are most easily loaded onto a vehicle, trailer, or base from the top or the side using a crane, forklift or other lifting device. Therefore such large or heavy items are more easily loaded onto a vehicle, trailer, or base having no sidewalls or no roof. Flatbed trucks and trailers are well adapted to carry such loads. However, as discussed above, it is often desirable to cover the loaded cargo during transport, as well as during storage. Tarpaulin cover systems provide an attractive solution as they can be quickly and easily retracted or removed to expose the entire cargo area during loading.
Tarpaulin cover systems are known in the art. For example, flexible tarpaulin systems for highway trailers have been disclosed in U.S. Pat. No. 5,152,575 to DeMonte et al., U.S. Pat. No. 5,538,313 to Henning, and U.S. Pat. No. 6,511,117 to Henning.
Retractable tarpaulin systems can come in a flat-top style, as taught by the two Henning patents, or in a peaked style, as taught by DeMonte. An increasingly common style of flexible cover system comprises a plurality of bows that support a flexible cover. The bows, and thus the cover, are moveable, typically along the length of the base or vehicle, and may be retracted in an accordion-like manner to expose a cargo area. The lower ends of each bow typically comprise sliding means, such as one or more wheels or rollers, which ride in or on a pair of tracks or rails on the base or vehicle.
It is important that the tarpaulin cover in retractable bow-style cover systems be fully stretched-out when the cover is in the extended position. In other words, it is important that tension be maintained in the tarp cover system. This is particularly significant for cover systems that are exposed to high winds or fast-moving air, such as cover systems positioned on vehicles. Firstly, applying and maintaining tension in the cover reduces the severity of flapping in the cover caused by the passing air or wind. A reduction in flapping reduces the material fatigue in the cover and in the bows, and therefore prolongs the service life of these parts. A reduction in flapping also reduces the amount of noise emitted and provides for a quieter ride. Secondly, a taut cover reduces the aerodynamic drag of the cover system. This likely increases the fuel or energy economy of the vehicle transporting the cover system. For the aforementioned reasons, it is desirable to have a satisfactory and substantially uniform tension in the flexible cover.
Tensioning devices and systems for sliding systems covers are also known in the art. Many existing systems involve the application of a force to the front-most or rear-most bow in order to fully stretch out the cover. For example, one such system is disclosed in U.S. Pat. No. 6,616,211 to Cramaro, which uses a crank and a lever that are connected to rear-most bow of the moveable tarpaulin framework. The crank is first rotated to move the lever into a catch position, and then counter-rotated to further extend the framework, which in turn stretches-out the cover.
However, known systems such as the one disclosed by Cramaro suffer from a number of shortcomings. In particular, the tensioning force applied in many existing systems is applied to a front-most or a rear-most bow at the lower ends of the bow. As a result, a satisfactory degree of tension can be applied and maintained in the lower side portions of the cover. However, the resultant tension in the upper side portions and the top portion of the cover will be lower than the tension achieved in the lower side portions. This difference can be at least partially attributed to the flexibility of the parts of the covering system, and in particular of the front-most or rear-most bow.
Existing tensioning devices and systems suffer from further shortcomings. Many systems are heavy or bulky, or both, and are therefore difficult to install and operate. Some systems are inefficient in that they require a significant amount of physical effort or time to achieve the desired degree of tension in the cover.
For the foregoing reasons, it can be appreciated that a need exists for a tarp tensioning and locking device that produces a satisfactory amount of tension in the entire cover, including the side portions and top portion of the cover. It is also desirable that the device be compact, lightweight, and easy to use.
SUMMARY
The present disclosure provides a tarp tensioning and locking device that addresses the problems described above. In particular, the present invention is directed to a sliding tarpaulin tensioning and locking device for achieving a sufficient amount of tension throughout a flexible cover and locking the tensioning in that position. The tensioning and lock device of the present invention comprises a base and an extending mechanism comprising an actuator. The actuator may be of the hydraulic, pneumatic, or mechanical variation and can be either manually or automatically powered. The device is lightweight, compact, easy to install and accomplishes its function in a minimal amount of time. Furthermore, the present invention is particularly well suited for retractable, flexible cover systems used in the trucking industry, but is also useful in other applications and in other fields.
In one aspect, the present disclosure is directed to a tarp tensioning and locking device comprising a base; and an extending mechanism for applying a tensioning force to a tarp, the extending mechanism being pivotally connected to the base, the extending mechanism comprising a bar and an actuator for extending or retracting the bar.
BRIEF DESCRIPTION OF THE DRAWINGS
The present disclosure will be better understood having regard to the drawings in which:
FIG. 1 is a perspective view of a flatbed trailer comprising a sliding tarp cover system and one embodiment of the cover tensioning device;
FIG. 1A is an enlarged view of inset 1 A shown in FIG. 1 ;
FIG. 2 is a perspective view of a pair of cover tensioning devices;
FIG. 3 is a sectional side view of a second embodiment of the cover tensioning device in the disengaged position; and
FIG. 4 is a sectional side view of a second embodiment of the cover tensioning device in the tensioned position.
DETAILED DESCRIPTION
The present tarp tensioning and locking device is described in one embodiment in the following disclosure with reference to the Figures. While this embodiment is described in the context of a sliding cover system installed on a flatbed trailer, the scope of the present disclosure is not intended to be limited to sliding cover systems on flatbed trailers. The present tarp tensioning device can be used in other applications and in other fields, including but not limited to tarp systems installed on other vehicles such as trains and ships, and tarp systems installed on separate shipping bases (i.e. not directly installed on a vehicle).
To provide a degree of background to the present invention, a known sliding tarp cover system is now described with reference to the Figures.
FIG. 1 shows a flexible cover system 200 installed on a base structure 300 , in this case a flat bed trailer. This cover system is shown in its extended (i.e. tightened) position. A tarp cover 202 is supported by a plurality of support members, or “bows”, over the trailer bed 300 thereby defining an enclosed cargo area. The sliding tarp system can comprise end bows at the front and rear, such as a rear bow 210 , and can also comprise one or more intermediate bows 230 . The end bows, such as rear bow 210 , may be of a more rigid construction to support the end loads of the tarp 202 . For example, as best shown in FIG. 1A , the rear bow 210 can comprise a pair of vertical support members 212 joined by braces 214 . The lower ends of each bow are slidably connected to the trailer bed 300 by way of a known wheel system. The slidable connection of the bows to guide members, such as tracks or rails 302 , enables the longitudinal movement of the bows along the length of the trailer 300 . The slidable connection may be formed by connecting one or more wheels 218 to the ends of a bow, each wheel riding in a track 302 positioned along an edge of the trailer 300 .
When the time comes to expose the cargo area of the trailer, the tarp cover 202 and plurality of bows 210 , 230 are moved towards one end of the trailer, usually the front end. The tarp cover 202 thereby collapses in an accordion-like manner. When the tarp 202 is to be moved into its extended position, the cover 202 and bows 210 , 230 are moved towards the opposite end of the trailer 300 , typically the rear end.
The various features and components of the present cover tensioning and locking device are now described.
As shown in FIGS. 1A and 2 , in at least one embodiment, the tensioning and lock device 100 of the present invention comprises an extending mechanism 120 and a base 130 . The device 100 may also comprise a vertical support 110 . It should be noted that FIG. 2 shows a pair of tensioning and lock devices 100 , which can be used in tandem.
In at least one embodiment comprising a vertical support, the vertical support 110 , extending mechanism 120 , and base 130 can be arranged in a triangular formation. The lower ends of both the vertical support 110 and the extending mechanism 120 are pivotally connected to the base 130 at spaced apart points on the base 130 . Furthermore, the upper ends of the vertical support 110 and the extending mechanism 120 can be pivotally connected to one another, or to a common connection member, such as an engagement member 112 .
The tensioning device 100 may be built to restrict the movement of the extending mechanism 120 , as well as a vertical support 110 , to a single plane of motion. This would prevent any unnecessary side-to-side movement of the extending mechanism 120 and vertical support 110 .
Vertical support 110 can serve as a guide and support for the extending mechanism 120 . In effect, the vertical support 110 directs the force exerted by the extending mechanism 120 in the desired direction to apply tension in the tarp cover 202 . In the embodiment illustrated in the Figures, the desired direction is towards the rear of the trailer and is substantially parallel to the longitudinal axis of the trailer. This direction is indicated by arrow Y in FIG. 3 . The application of force in this direction will fully extend the cover system 200 and will produce tension in the tarp cover 202 .
As best illustrated in FIG. 1A , the tensioning system 100 can comprise an engagement member 112 for engaging the cover system 200 . The engagement member 112 can be connected to or formed integrally with the upper end of the extending mechanism 120 . In at least one embodiment, the engagement member 112 is adapted to engage a bow, such as rear bow 210 . For example, in the embodiment shown in FIG. 1A , the engagement member 112 can comprise a recess or notch 114 for engaging a mechanical obstruction, such as a pin 220 , on the bow. The pin 220 can comprise a stop member 222 at its distal end to prevent the engagement member 112 from slipping off of the pin 220 when force is applied to the pin 220 by the tensioning device 100 . The engagement member 112 can further comprise securing means to releasably secure it to the cover system 200 , including but not limited to a clip, a clamp, and any other suitable type of fastener.
The relative height at which the tensioning device 100 applies force to a bow, such as the rear bow 210 , is an important consideration. In particular, the relative height at which the extending member 120 applies the tensioning force to the tarp 202 , or the rear bow 210 , should not be overlooked. It is desirable to obtain a satisfactory and substantially uniform amount of tension in all areas of the tarp cover 202 , which includes lower and upper side portions 204 , 206 and the top portion 208 (see FIG. 1 ). One way to achieve a satisfactory and substantially uniform degree of tension in the tarp cover 202 is to position the upper end of the extending mechanism 120 such that it exerts a tensioning force at approximately the vertical midpoint of the tarp cover 202 or rear bow 210 . The embodiment of the tensioning device 100 shown in FIG. 1 has such a configuration. Such a configuration should provide a satisfactory and substantially uniform amount of tension in the lower and upper side portions 204 , 206 of the cover as well in the top portion 208 . However, if the extending mechanism 120 engages the cover 202 or rear bow 210 at too low of a height, then the degree of tension in the upper side portions 206 and the top portion 208 of the cover 202 may be inadequate. Likewise, if the extending mechanism 120 engages the cover 202 or rear bow 210 at too high of a height, then the degree of tension in the lower side portions 204 of the cover 202 may be inadequate.
The extending mechanism 120 comprises a rigid extension member, such as a bar 122 , and also comprises an actuator 124 . The actuator 124 is connected to the bar 122 , and selectively extends and retracts the bar 122 in the directions indicated by arrow X (see FIG. 1A ).
The actuator 124 can be powered either manually (e.g. by hand) or automatically (i.e. by another energy source), and should be capable of producing a sufficient amount of force to obtain satisfactory amount of tension in the tarp cover 202 . In addition, it is very important that the actuator 124 be capable of entering a locked state, in which any further extension or retraction of the bar 122 is resisted. When a plurality of tensioning devices 100 are used together, the actuators 124 of each device can be powered individually or collectively. As best shown in FIG. 2 , in at least one embodiment the actuator 124 is a hydraulic cylinder, which is part of a manually powered hydraulic system 250 . The hydraulic cylinder is fluidly connected to a master cylinder 252 by hydraulic line 254 . The master cylinder 252 can comprise a handle 256 for manual operation.
As mentioned above, FIG. 2 shows a pair of tensioning and lock devices, which can be used in tandem to form a single tensioning system. In the embodiment shown in FIG. 2 , the two tensioning devices 100 are powered by the same hydraulic system 250 . The line exiting the master cylinder 252 splits into two separate lines, each one being fluidly connected to one of the tensioning devices 100 . Alternatively, each tensioning and lock device 100 could have separate means to power its actuator 124 .
In addition, a person skilled in the art would appreciate that suitable alternatives to a manually operated hydraulic system exist to power the actuator 124 . That is, the actuator 124 can comprise any other suitable means for selectively extending and retracting the extension member or bar 122 . These means include but are not limited to pneumatic devices or systems; mechanical devices or systems including but not limited to worm gear mechanisms, ratchet mechanisms, rack and pinion gear mechanisms; as well as other mechanical, hydraulic, pneumatic and electrical means.
In addition to supporting the extending mechanism 120 , and in some instances a vertical support 110 , the base 130 can serve as a mounting point for the tensioning and lock device 100 . As shown in FIG. 1A , in at least one embodiment the base 130 engages a mounting plate 140 , which can be installed on the base structure 300 , such as a trailer or truck bed. The engagement of the base 130 with the mounting plate 140 may be a releasable engagement thereby allowing for quick and easily installation and removal of the tensioning and lock device 100 from the base structure 300 .
Although the base 130 is depicted in the Figures as an elongate member, it is to be understood that the base 130 can take other shapes and forms, and may be much shorter and or smaller than depicted. This is particularly so where the tensioning device 100 does not comprise a vertical support 110 . In such a configuration, the base 130 does not support a vertical support 110 and therefore need not have an elongate shape.
The operation of the present cover tensioning device is now described. FIGS. 3 and 4 show the tensioning device 100 in two different stages of operation. FIG. 3 shows the tensioning device 100 in the disengaged position, whereas FIG. 4 shows it in the engaged, or tensioned, position. In FIG. 3 , the rear bow 210 and thus the tarp cover 202 is not fully extended towards the rear of the base or trailer 300 , and the extending mechanism 120 of the tensioning device 100 is in a retracted state. In operation, the engagement member 112 of the tensioning device 100 is positioned in contact with or in proximity to the pin 220 on the rear bow 210 . The actuator 124 is then activated, thereby extending the bar 122 of the extending mechanism 120 . As the extending mechanism 120 extends, it pivots the upper portion of vertical support 110 , as well as the engagement member 112 connected to the upper end thereof, in the direction indicated by arrow Y. The force of the extending mechanism 120 is applied to the pin 220 , and thus the bow 210 , also in the direction of arrow Y. This force expands the cover 202 in the same direction, in this case towards the end of the base structure or trailer 300 . Once the desired degree of tension in the cover 202 has been achieved, the actuator 124 is deactivated and the cover 202 is held in a tensioned and locked state. To release the tension in the cover 202 , the actuator 124 is selectively activated to retract the bar 122 .
The present cover tensioning device 100 has herein been described and illustrated as being disposed at the rear end of a base structure or trailer 300 . However, it is to be understood that the tensioning device 100 can be positioned at various other suitable locations relative to a tarp cover system. For example, the device 100 can be installed at the front end of a base structure or trailer. Furthermore, one or more tensioning devices 100 can be positioned at opposite ends (e.g. front and rear) of a base structure or trailer 300 .
The previous detailed description is provided to enable any person skilled in the art to make or use the present invention. Various modifications to those embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention described herein. Thus, the present invention is not intended to be limited to the embodiments shown herein, but is to be accorded the full scope consistent with the claims, wherein reference to an element in the singular, such as by use of the article “a” or “an” is not intended to mean “one and only one” unless specifically so stated, but rather “one or more”. All structural and functional equivalents to the elements of the various embodiments described throughout the disclosure that are known or later come to be known to those of ordinary skill in the art are intended to be encompassed by the elements of the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims.
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The present invention is directed to a tensioning and lock device for achieving a sufficient amount of tension throughout a tarp cover. The present invention is particularly well suited for retractable, tarp cover systems used in the trucking industry, but is also useful in other applications and in other fields. The tensioning and lock device comprises a base and an extending mechanism comprising an actuator. The actuator may be of the hydraulic, pneumatic, or mechanical variation and can be either manually or automatically powered. The present tensioning device is lightweight, compact, easy to install and accomplishes its function in a minimal amount of time.
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PRIORITY CLAIM
This application claims priority on provisional application 62/017,936 named “Low Cost Probes for Slide Screw Tuners”, filed on Jun. 27, 2014.
CROSS-REFERENCE TO RELATED ARTICLES
1. Load Pull Measurements, http://en.wikipedia.org/wiki/Load_pull.
2. “Computer Controlled Microwave Tuner—CCMT”, Product Note 41, Focus Microwaves, January 1998.
3. Standing wave ratio, VSWR, https://en.wikipedia.org/wiki/Standing_wave_ratio.
4. Corona discharge, http://en.wikipedia.org/wiki/Corona_discharge.
5. “High Resolution Tuners Eliminate Load Pull Performance Errors”, Application Note 15, Focus Microwaves, January 1995.
6. HFSS, High frequency electro-magnetic simulator, http://en.wikipedia.org/wiki/HFSS.
7. TSIRONIS, U.S. Pat. No. 7,248,866, “Frequency selective load pull tuner and method”.
8. Anodization, http://en.wikipedia.org/wiki/Anodizing.
9. TSIRONIS, U.S. Pat. No. 8,410,862, “Compact Multi Frequency-Range Impedance Tuner”, FIGS. 2b) and 17.
BACKGROUND OF THE INVENTION
This invention relates to RF load and source pull testing of medium and high power RF transistors and amplifiers using remotely controlled electro-mechanical impedance tuners.
Modern design of high power and low noise RF amplifiers and mixers, used in various communication systems, requires accurate knowledge of the active device's (microwave transistor's) characteristics. In such circuits, it is insufficient for the transistors, which operate in their highly non-linear regime, close to power saturation, to be described using non-linear numeric models.
A popular method for testing and characterizing such microwave components (transistors) is “load pull” or “source pull”. Load/Source pull is a measurement technique employing microwave tuners and other microwave test equipment ( FIG. 1 ), such as signal source ( 1 ), input and output tuner ( 2 , 4 ), power meter ( 5 ) and test fixture ( 3 ) which comprises the device under test (DUT). The tuners and equipment are controlled by a computer ( 6 ) via digital cables ( 7 , 8 , 9 ). The microwave impedance tuners are used in order to manipulate the microwave impedance conditions under which the DUT (transistor) is tested (see ref. 1); this document refers hence to “impedance tuners”, in order to make a clear distinction to “tuned receivers (radios)”, popularly called elsewhere also “tuners” because of the included tuning circuits (see ref. 2).
Electro-mechanical impedance tuners ( FIG. 2 ) in the frequency range between 100 MHz and 60 GHz use the slide-screw concept and include a slabline ( 24 ) with a center conductor ( 23 ) and one or more mobile carriages ( 28 ) which carry a motor ( 20 ), a vertical axis ( 21 ) and control the vertical position ( 216 ) of a reflective probe ( 22 ). The carriages are moved horizontally ( 217 ) by additional motors and gear ( 27 ). The signal enters into one port ( 25 ), the “test port”, and exits from the other port ( 26 ), the “idle port”; in the case of the input tuner ( 2 ) the test port is the signal exit port, whereas in the case of the output tuner the test port is the signal entry port. The entire tuner mechanism is, typically, integrated in a solid housing ( 215 ) since mechanical precision is of highest priority.
The typical configuration of the core of the tuner is shown in FIGS. 3 and 4 ; it comprises, in general, a slotted transmission airline ( 31 , 44 ) and a number of metallic parallel tuning elements ( 30 , 41 ) also called “tuning” probes, “reflective” probes or “slugs”, which are coupled with the center conductor to an adjustable degree, depending from very low coupling (when the probe is withdrawn) to very strong coupling (when the probe is within Corona discharge distance from the center conductor, see ref. 4). “Sampling” probes on the other hand are loosely coupled with the center conductor and only detect a small amount of the signal power.
When the tuning probes approach ( 34 , 44 ) the center conductor ( 32 , 43 ) of the slabline ( 31 , 44 ) and moved along the axis ( 45 ) of the slabline, they modify the amplitude and phase of the reflection factors, covering parts or the totality of the Smith chart (the normalized reflection factor area). The relation between reflection factor and impedance is given by GAMMA=(Z−Zo)/(Z+Zo), where Z is the complex impedance Z=R+jX and Zo is the characteristic impedance. A typical value used for Zo is 50 Ohms (see ref. 3).
Up to now such tuning metallic probes (slugs) have been made in a cubical form ( 30 , 41 ) with a concave bottom ( 35 ) which allows capturing, when approaching the center conductor ( 32 , 43 ), the electric field which is concentrated in the area ( 36 ) between the center conductor ( 32 ) and the ground planes of the slabline ( 31 ) ( FIGS. 3 and 13 ), where the center conductor is closest to the internal surface of sidewalls ( 37 ). This field capturing allows creating high and controllable reflection factors. Contact of the probes with the sidewalls ( 37 ) is critical. It can be either capacitive or galvanic. If the contact is capacitive, the surface of the probes and/or the sidewalls of the slabline must be electrically insulated. This can be done using chemical process such as “anodization” (see ref. 8). Nevertheless capacitive contact means extreme requirement in sidewall planarity and straightness to keep the quasi sliding contact constant for the whole length and depth of the slabline as the probe travels.
Galvanic contact is safer, but requires a spring mechanism to allow for constant pressure of the probe on the sidewalls. The two possible scenarios (capacitive and galvanic contact) are shown in FIG. 5 ; FIG. 5 a ) shows a probe ( 56 ) with galvanic ground contact ( 50 ) and FIG. 5 b ) a probe ( 55 ) with capacitive contact ( 54 ) with the slabline walls ( 56 , 57 ). Probe 5 a ) must have a springing mechanism ( 51 ) which is created by machining a horizontal hole and slot ( 52 ) into the body of the probe. Probe 5 b ) can be massive ( 55 ).
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
The invention and its mode of operation will be more clearly understood from the following detailed description when read with the appended drawings in which:
FIG. 1 depicts prior art, a typical automated transistor load pull test system.
FIG. 2 depicts prior art, a frontal cross section of an automated slide screw impedance tuner using a single vertical axis and RF probe (slug).
FIG. 3 depicts prior art, cross section of RF tuning probe inside a slotted airline (slabline) approaching the center conductor.
FIG. 4 depicts prior art, a perspective view of relevant dimensions and parameters of the operation of a vertically adjustable RF tuning probe (slug).
FIG. 5 depicts prior art: front views of cubical tuning probes with galvanic ground contact ( 5 a ) and capacitive ground contact ( 5 b ).
FIG. 6 depicts a cross section of the new tubular tuning probe and the control mechanism for vertical movement inside the slabline.
FIG. 7 depicts a perspective view of the new tuning probe placed for maximum coupling and reflection factor close to the center conductor.
FIG. 8 depicts frequency response of the reflection factor (S11) of the new probe inside a slabline for a number of vertical positions (gap sizes between probe and center conductor).
FIG. 9 depicts a comparison of wideband reflection factor (S11) between a prior art probe ( FIG. 5 a ) and the new probe ( FIG. 6 ).
FIG. 10 depicts a setup for calibrating a tuner, which uses the new probes.
FIG. 11 a ) through 11 b ): 11 a ) depicts perspective view of new probe for higher frequencies (Fmax=50 GHz); 11 b ) depicts the frequency response of the reflection factor of the high frequency probe at maximum coupling (closest to center conductor).
FIG. 12 depicts a variance of the new probe in an easier to manufacture form (no edge treatment).
FIG. 13 a ) through 13 b ): 13 a ) depicts the electric field distribution in a slabline in the area of the tuning probe having galvanic ground contact, when the tuning probe approaches the center conductor; 13 b ) depicts a detail in the area of the ground contact.
FIG. 14 depicts the electric field distribution in a slabline in the area of the tuning probe having capacitive ground contact.
FIG. 15 a ) through 15 b ): 15 a ) depicts partly prior art: the tuning probes of frequency selective tuner (U.S. Pat. No. 7,248,866) and 15 b ) depicts the new probes.
DETAILED DESCRIPTION OF THE INVENTION
This invention discloses new tuning probes for electro-mechanical and manual slide screw impedance tuners. The basic form of the new probes and their typical cross-section are shown in FIGS. 6, 7, 11 a ), 12 , 13 and 15 b ). A thorough analysis of the electric field distribution in the slabline around the center conductor leads to the conclusion that the massive body of the prior art tuning probes (slugs) has no vital effect on the reflected energy. It would therefore be logical to eliminate it, if there would be another advantage; and there is:
Manufacturing prior art structures ( FIG. 5 ) is tedious, both, in the case of slugs with spring effect to make galvanic ground contact ( FIG. 5 a ) and in the case of solid slugs with capacitive ground contact ( FIG. 5 b ). In the case of FIG. 5 a ) the hole ( 52 ) must be placed very carefully in the center of the slug in order to achieve the right symmetrical pressure and similar (identical if possible) spring effect ( 51 ) of the galvanic contact ( 50 ) on both sidewalls. Equally the exact width of the slot ( 58 ) is critical and must be kept small to avoid resonances which may appear (item ( 95 ) in FIG. 9 ). In the case of solid slugs, having capacitive ground contact, the manufacturing requirements have been discussed before: extreme precision in all dimensions, slugs and slabline uniformity and surface treatment must fit perfectly, in order to establish smooth slug travel along the whole horizontal and vertical travel of the slug inside the slabline to keep the capacitance constant; and to avoid the risk of “rubbing off” the extremely thin insulation layer between slug and slabline wall, which is necessary to reach sufficient capacitance (and low grounding resistance).
The new tuning probes have the approximate form of a half tube or axially cut cylinder ( FIGS. 6, 7, 11 a ) and 12 ). Typically the probe periphery extends beyond half the cylinder, in order to reach beyond the center of the center conductor and capture a maximum of the electric field ( 134 ), ( 130 ) when the tube is closest to the center conductor ( 131 ); the electric field is concentrated between the center conductor ( 131 ) and the grounded slabline sidewalls ( 133 ), FIG. 13 b ). Maximum reflection is created when the distance between the probe ( 132 ) and the center conductor ( 131 ) is at a minimum, whereby the maximum deformation and capture of the electric field ( 134 ) occurs.
Ground contact of the probe with the slabline walls can be galvanic ( FIG. 13 ) or capacitive ( FIG. 14 ); in the case of capacitive contact the probe edge ( 144 ) slides vertically and horizontally flat ( 146 ) on a thin dielectric layer ( 141 ), which is deposited on the sidewall ( 142 ) of the slabline. The electric field is still concentrated in the area ( 140 ) between the center conductor ( 143 ) and the sidewall ( 142 ); the field distribution is symmetrical to the center of the slabline (left side not shown in FIG. 14 ); it is important that the contact area ( 147 ) is large enough for creating the capacitance needed to be considered a RF short circuit: using the relation |Z|=1/(2π*C*freq) one can estimate that, at 5 GHz the capacitance needed for a ground resistance to be 5 Ohm is C≈6.3 pF; using the relation C=∈o*∈r*A/s, whereby A is the contact area, s is the thickness of the dielectric layer (coating) and ∈r its dielectric constant, ∈o=8.854 pF/m and assuming ∈r=4 for some Teflon or other plastic material having a thickness of 0.00005 m (50 μm), we obtain a required surface contact area A=8.9 mm 2 This is a realistic number to achieve, assuming the probe being 10 mm long, the contact height ( 147 ) should be less than 1 mm Considering also that the probe makes contact on both sidewalls simultaneously, creating two parallel resistances, such dimensions would generate a total grounding resistance of half the size, i.e. 2.5 Ohms The relations shown here are applicable in general, so various alternatives can be considered.
The thickness of the tube material ( 132 ) is easily controlled: for low frequency (long) probes ( FIGS. 7 and 8 ) the material will be thinner than in (short) high frequency probes ( FIG. 11 ) in order to control the elasticity of the tube and by that the pressure ( 120 ) of the probe wings on the slabline sidewall ( 125 ). Numerical simulation using HSFSS (see ref. 6) shows the new probes ( FIGS. 6, 7, 11 a and 12 ) to have the same or better tuning capability (maximum reflection factor response or “tuning range”) as prior art cubical (block) probes ( FIGS. 8, 9 and 11 b ) see ref. 5 . FIG. 8 shows the wideband reflection factor response of the new probes as a function of penetration into the slabline (distance between probe bottom and center conductor); traces ( 82 , 83 , 84 , 85 ) correspond to the frequency response at large gaps. When the probe is completely withdrawn the electric field is not disturbed and the tuner behaves as a matched transmission line. Trace ( 81 ) is at maximum penetration (smallest gap between probe and center conductor); the smallest gap allowed, before electrical discharge, depends, obviously, on the applied RF power and DC voltage through the tuner. The electric field shall not exceed the discharge (Corona) value in air (approximately 4V/μm, see ref. 4).
Depending on the application the stabs holding the probes ( 67 ) can be dielectric (non-conductive) in order to avoid resonances, or metallic. In a previous patent (see ref. 7) resonant tuning probes were disclosed ( FIG. 15 a ). The difference to the new probes ( FIG. 15 b ) is that in those resonant probes the tubular body was floating and did not have ground contact with the sidewalls of the slabline, neither galvanic nor capacitive; the holding stab is conductive, since the entire function of the probe relies on the series resonance created between the stab's ( 115 in FIG. 15 a ) inductive behavior and the capacitance between the floating probe body ( 58 in FIG. 15 b ); whereas in the present invention the probe body ( 151 in FIG. 15 b ) is grounded ( 152 ).
In FIG. 15 the structure of the carriage ( 157 ), which slides horizontally on the slabline ( 158 ) is shown. The vertical motor ( 156 ) holds the vertical axis ( 155 ) which holds the holding stab ( 153 ) of the tuning probe ( 151 ). Horizontal carriage control is as in prior art (motor, gear ( 27 ) and lead-screw ( 29 ) in FIG. 2 ). If the stabs ( 153 ) are conductive then, depending of the RF termination on their end which is not attached to the probe, they may create an RF short circuit at a given frequency at the probe contact ( 154 ): if the (conductive) stab ( 153 ) is open (i.e. insulated electrically from the vertical axis) and has an electrical length of λ/4 or it is shorted (i.e. electrically connected to the grounded vertical axis) and has a length of λ/2, in both cases it will create an RF short at the top of the probe ( 154 ). At frequencies in-between, a conductive stab will create some capacitive or inductive load at the top of the probe, which, in combination with the capacitance between the probe and the center conductor, and, depending on the grounding method of the tube edges ( 152 ) (especially in the case of capacitive grounding ( 146 )) it may create undesired and unpredictable resonances (see ref. 7).
In a manual tuner configuration (not shown) the vertical motor ( 156 ) and axis ( 155 ) are replaced by a micrometer screw and horizontal movement is either by pushing the sliding carriage ( 157 ) by hand along the slabline ( 158 ), or by replacing the horizontal motor ( 27 ) by a rotating knob and using the same lead-screw ( 29 ), or by replacing the horizontal gear ( 27 ), ( 29 ) completely by a second micrometer screw. This would be more practical for high frequency tuners, where horizontal travel is short.
Beyond simpler manufacturability a further, practical advantage of the new probe structure is low sensitivity to vibrations: tuners are moved and shipped. During transportation they are subject to shocks and sudden accelerations/decelerations; the massive prior art probes will vibrate because they have a higher mass and will apply lateral force on the vertical axis, which supports them; this may even damage the vertical axis on which they are mounted. The new probes are less sensitive to shocks, and apply less stress on the vertical axis, because they have much lower mass.
Tuner calibration at a selected frequency F comprises a number of steps, whereby the probe(s) ( 103 ) are placed at various vertical and horizontal positions inside the slot of the slabline ( 109 ) and the s-parameters are measured between the tuner ports using a pre-calibrated network analyzer ( 100 ) and saved, the total being controlled remotely ( 108 ) by a system computer ( 102 ). Each probe ( 103 ) is scaled, i.e. moved from a high (withdrawn) initial position into the slabline ( 109 ) towards the center conductor, to generate a number of reflection factor levels, which, depending on the application and resolution required, may vary from 5 to 20, from a minimum (residual reflection S11.min or GAMMA.min) value to a maximum S11.max (as required by the application): residual S11.min values are typically around 0.05 or less and maximum values S11.max depend on probe size and frequency and can reach S11.max>0.95; the ratio S11.max/S11.min is the tuning range of the probe. The measured reflection factor (S11) is associated with the corresponding vertical position of the probe and saved. In the case of multiple probes in the same carriage (this configuration is used in the case when each probe covers a different frequency range, see ref. 9 , FIG. 2( b ) , items (High frequency probe) and (Low frequency probe) and FIG. 17 ) the procedure is repeated for each probe. In the case of multiple independent carriages the s-parameters of the initialized tuner, i.e. when the probes are withdrawn and moved to horizontal initial position, are measured and saved as matrix [S0]. This matrix [S0] is used later to be de-embedded (multiply the invers of its equivalent transmission matrix (T-matrix) [T0] −1 with the equivalent T-matrices of s-parameters) from s-parameters of all probes except for the probe closest to the test port. In that context s-parameters of a probe “N” means s-parameters of the whole tuner measured between the test and the idle port, with probe N moving and all other probes initialized. All s-parameters of all probes are saved and permutations of s-parameters for the individual probe positions are generated numerically and saved in calibration files.
During tuning operations the s-parameters are retrieved from calibration files in memory for given probe position(s) and are, either used as such, or used to calculate interpolated s-parameters and subsequently measure and associate the measured DUT data to the corresponding reflection factor, which is the essence of load/source pull (see ref. 1).
Obvious alternatives to the disclosed concept of low cost semi-cylindrical RF probes for slide screw tuners are imaginable but shall not impede on to the validity of the present invention.
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A new tuning probe for slide-screw impedance tuners uses a simplified semi-cylindrical tubular form. This ensures reduced manufacturing cost and high machining tolerance for probes using galvanic ground contact. RF performance matches or exceeds traditional cubical probes both using galvanic and capacitive ground contacts.
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FIELD OF THE INVENTION
[0001] The present invention relates to a building system. More particularly the invention relates to stucco type cavity wall construction techniques and resultant consumables, subassemblies, assemblies, etc.
[0002] Exterior panels defined in situ in a plaster material in New Zealand have been restricted to a height no higher than about 2.4 meters high and 4 meters wide by building regulation. Larger cladding areas require movement control joints.
[0003] The present invention in one aspect is directed to a building system (eg. structures, methods, procedures, apparatus, etc) which would allow panels of greater than 2.4 meters in height to be created and/or greater than 4 meters width to be created without movement joints.
[0004] The present invention also or instead is directed to building envelopes being closed by a cavity wall plaster system which, with our without movement control joints (eg. vertical and/or horizontal control joints), can provide walls of considerable size and/or non-square or non-rectangular perimeter.
BACKGROUND OF THE INVENTION
[0005] For a typical (nominal) 21 mm panel thickness in compliance with NZS3604, we envisage at least square or rectangular panels being created in situ that can achieve, without a movement control joint, a height of at least 4.85 meters and can be as wide as much as, for example, up to 12 meters, all without mandatory movement control joints. Smaller panel widths of 6 meters, 8 meters or other are also within the compass of the present invention. Likewise heights.
[0006] By way of example, and without in any way being limiting, we expect for an in situ panel, of say 21 mm thickness so as to be NZ compliant, a single level panel size of, say, 2.4×6 metres and a double level panel size of say, 5.2×8 metres without any mandatory movement control joint.
[0007] In other countries (eg. USA) a thicker panel of say, about 40 mm may find favour. We expect our system to cater similarly for such panels.
[0008] Irrespective of the dimensions of any resultant panel, its peripheral shape, etc any method of in situ formation of a reinforced plaster panel that allows that greater dimensional reach of a panel is also within the scope of the present invention. However a preferred system of plaster matrix will be described with respect to NZ requirements but in no way restricted to NZ regulatory constraints.
[0009] It is an aim or object of the present invention to provide a building and/or a building system, related assemblies, sub assemblies, procedures, methods, panels, flashings, reinforcements, cavity walls of part stucco construction, etc which will at least provide the public with a useful choice.
[0010] It is a further or alternative aim or object of the present invention to provide compliance with the plaster code NZS4251 in the provision of a building and/or a building system, related assemblies, subassemblies, procedures, methods, panels, flashings, reinforcements, cavity walls of part stucco construction etc, all which will at least provide the public with the useful choice.
[0011] It is a further or alternative aim or object of the present invention to provide compliance with the building code NZS3604 in the provision of a building and/or a building system, related assemblies, subassemblies, procedures, methods, panels, flashings, reinforcements, cavity walls of part stucco construction etc, all which will at least provide the public with the useful choice.
[0012] It is a further or alternative aim or object of the present invention to provide compliance with the building code NZS3604 and plaster code NZS4251 in the provision of a building and/or a building system, related assemblies, subassemblies, procedures, methods, panels, flashings, reinforcements, cavity walls of part stucco construction etc, all which will at least provide the public with the useful choice.
[0013] It is a further or alternative aim to provide stucco walled structures having panel rigidity and integrity.
[0014] It is a further or alternative aim or object of the present invention, or at least some embodiments, of the present invention to provide methods to meet what is expected to be allowable under NZ regulation.
BRIEF DESCRIPTION OF THE INVENTION
[0015] In an aspect the invention is a building which has as a wall of its envelope, a wall of a size of at least 2.4 m high, at least 4 m wide and about 21 mm thick;
[0016] wherein the wall has
[0017] a frame or a substructure having studs at least some of which are spaced by a modular distance,
[0018] battens supported from and fixed to said frame or substructure, such battens fixed both on and between studs,
a first mesh (“inner mesh”) attached to such battens, a second (“outer”) mesh supported at least in part by a plaster matrix, and the plaster matrix applied as more than one layer, the plaster matrix penetrating the first mesh, interposing both meshes, attaching to the second mesh and covering the second mesh;
[0021] wherein the wall has at least one opening selected from a group consisting of door and window openings;
[0022] and wherein at least part of the periphery of each opening, within the matrix, has been further reinforced by one or more of
(a) one or more of at least one mesh and/or lattice-work at each corner, (b) one or more of at least one mesh and/or lattice-work at each vertical side, and/or (c) one or more mesh between adjacent openings.
[0026] Preferably the studs are of minimum cross-section of 45 mm×90 mm.
[0027] Preferably there are dwangs at nominal 900 mm spacings between the studs.
[0028] Preferably the batten attached mesh is of a metal.
[0029] Preferably the batten attached mesh overlies a backing sheet.
[0030] Preferably the battens are of nominal 35 mm×40 mm cross-section.
[0031] Preferably the second mesh is non-metallic
[0032] Preferably regional reinforcement is by or includes metallic mesh.
[0033] Preferably the metallic mesh regional reinforcement has been attached prior to being embedded.
[0034] Preferably regional reinforcement is by or includes a non-metallic sheet material or mesh able to be embedded and penetrated by the matrix material.
[0035] Preferably panel boundaries include at least partially embedded lattice-like periphery defining members.
[0036] In another aspect the invention is a building which has a wall that has
[0037] a frame or a substructure that includes studs substantially to a modularly spacing of about 600 mm where suitable,
[0038] battens supported from and fixed to said frame or substructure, said battens being fixed both to at least the modularly spaced studs and inbetween,
[0039] a first mesh attached to such battens,
[0040] a second mesh supported at least in part by a plaster matrix, and
[0041] one or more additional mesh as regional mesh reinforcement,
[0042] the plaster matrix applied as more than one layer, the plaster matrix penetrating the first mesh, embedding the second mesh, embedding the regional mesh or meshes.
[0043] Preferably the studs are of minimum cross-section of 45 mm×90 mm.
[0044] Preferably there are dwangs (preferably at nominal 900 mm spacings) between the studs.
[0045] Preferably the batten attached mesh is of a metal.
[0046] Preferably the batten attached mesh overlies a backing sheet.
[0047] Preferably the battens are of nominal 35 mm×40 mm cross-section.
[0048] Preferably the second mesh is non-metallic
[0049] Preferably regional reinforcement is by or includes metallic mesh.
[0050] Preferably the metallic mesh regional reinforcement has been attached prior to being embedded.
[0051] Preferably regional reinforcement is by or includes a non-metallic sheet material or mesh able to be embedded and penetrated by the matrix material.
[0052] Preferably panel boundaries include at least partially embedded lattice-like periphery defining members.
[0053] In still another aspect the invention is a stucco wall comprising or including
[0054] a stud including wall frame,
[0055] battens carried by the wall frame and in excess of the number of studs in the wall frame,
[0056] a mesh or the like perforate reinforcement sheet(s) carried by the battens,
[0057] a mesh or the like perforate reinforcement sheet(s) outwardly of and spaced from the batten carried sheet(s),
[0058] additional regional reinforcement mesh,
[0059] lattice and/or perforate reinforcement, and
[0060] a plaster or cementitious matrix, applied as at least a two layer application, that penetrates the batten carried sheet(s) and embeds or also embeds the other said reinforcement(s).
[0061] Preferably the studs are of minimum cross-section of 45 mm×90 mm.
[0062] Preferably there are dwangs (preferably at nominal 900 mm spacings) between the studs.
[0063] Preferably the batten attached mesh is of a metal.
[0064] Preferably the batten attached mesh overlies a backing sheet.
[0065] Preferably the battens are of nominal 35 mm×40 mm cross-section.
[0066] Preferably the second mesh is non-metallic
[0067] Preferably regional reinforcement is by or includes metallic mesh.
[0068] Preferably the metallic mesh regional reinforcement has been attached prior to being embedded.
[0069] Preferably regional reinforcement is by or includes a non-metallic sheet material or mesh able to be embedded and penetrated by the matrix material.
[0070] Preferably panel boundaries include at least partially embedded lattice-like periphery defining members.
[0071] In another aspect the invention is a building which has as a wall of its envelope, a wall of a size of at least 2.4 m high, at least 4 m wide and about 21 mm thick;
[0072] wherein the wall has
[0073] a frame or a substructure,
[0074] battens supported from and fixed to said frame or substructure,
[0075] a first mesh (“inner mesh”) attached to such battens,
[0076] a second (“outer”) mesh supported at least in part by a plaster matrix, and
[0077] the plaster matrix applied as more than one layer, the plaster matrix penetrating the first mesh, interposing both meshes, attaching to the second mesh and covering the second mesh;
[0078] wherein the wall has at least one opening selected from a group consisting of door and window openings;
[0079] and wherein the, or each, opening is positioned only as allowed and the, or each, opening is further reinforced in the plaster matrix at least substantially in accordance with the Rules as herein provided (preferably thereby to be NZS3604, or both NZS3604 and NZS4251, compliant, all as current June 2010).
[0080] Preferably the frame or substructure has studs that are of minimum cross-section of 45 mm×90 mm.
[0081] Preferably there are dwangs at nominal 900 mm spacings between the studs.
[0082] Preferably the batten attached mesh is of a metal.
[0083] Preferably the batten attached mesh overlies a backing sheet.
[0084] Preferably the battens are of nominal 35 mm×40 mm cross-section.
[0085] Preferably the second mesh is non-metallic
[0086] Preferably regional reinforcement is by or includes metallic mesh.
[0087] Preferably the metallic mesh regional reinforcement has been attached prior to being embedded.
[0088] Preferably regional reinforcement is by or includes a non-metallic sheet material or mesh able to be embedded and penetrated by the matrix material.
[0089] Preferably panel boundaries include at least partially embedded lattice-like periphery defining members.
[0090] In yet another aspect the invention is a building having at least one stucco wall, the stucco matrix having been layed up as plural settable layers, the wall being of at least 2.4 m high, at least 4 m wide and about 21 mm thick, the wall comprising or including
[0091] a frame or a substructure that includes studs of at least 45×90 mm cross-section, where appropriate, at about 600 mm centres,
[0092] battens of about 40 by 35 mm cross-section supported from the frame or substructure both on and in
[0093] between the studs,
[0094] reinforcement metal mesh attached to the battens and penetrated by a said layer of the stucco matrix,
[0095] reinforcement set out from the batten carried metal mesh and embedded in the stucco matrix,
[0096] regional extra embedded reinforcement, and
[0097] the stucco matrix
[0098] Preferably there are dwangs at nominal 900 mm spacings between the studs.
[0099] Preferably the batten attached mesh is of a metal.
[0100] Preferably the batten attached mesh overlies a backing sheet.
[0101] Preferably the second mesh is non-metallic
[0102] Preferably regional reinforcement is by or includes metallic mesh.
[0103] Preferably the metallic mesh regional reinforcement has been attached prior to being embedded.
[0104] Preferably regional reinforcement is by or includes a non-metallic sheet material or mesh able to be embedded and penetrated by the matrix material.
[0105] Preferably panel boundaries include at least partially embedded lattice-like periphery defining members.
[0106] In another aspect the invention consists in a building [or any kit, method or procedures which results in such a building] which has, or is to have, as part of its envelope and/or any wall,
a frame or a substructure, battens supported from and fixed to said frame or substructure, a first mesh (“inner mesh”) attached to such battens, a second mesh (“outer mesh”) supported at least in part by a plaster matrix, and the plaster matrix applied as more than one layer; wherein the plaster matrix penetrates the first mesh, interposes both meshes, attaches to the second mesh, and covers the second mesh;
[0113] wherein the panels (at least of said primary plaster matrix and the meshes has one or more of the following characteristics,
is about 21 mm thick is of a size of at least 2.4×4 m has no movement control joints has movement control joints mandated by the Rules hereafter has extra mesh reinforcement outwardly of the corners of openings has extra mesh reinforcement between openings has said extra mesh positioned within a base layer of the plaster matrix, the plaster matrix being of several applied layers has embedded unfixed extra mesh reinforcement mandated by the Rules hereafter has such extra reinforcement mandated by the Rules positioned within a layer of the plaster matrix, the plaster matrix being of several applied layers.
[0123] Preferably the first mesh is a metal mesh.
[0124] Preferably said first mesh “wraps” (as herein defined) the framing or substructure over the battens and to and/or substantially to any openings of the envelope.
[0125] Preferably prepared mesh sheet (preferably zinc coated) has been used as the inner mesh, paper side inwards.
[0126] Preferably the pre-papering provides, as if formwork, for first layer plaster application capture behind and to the inner mesh.
[0127] Preferably, or optionally, the inner mesh is of vertical and horizontal wire.
[0128] Optionally and preferably corners of openings have as additional reinforcement for and/or support for the plaster matrix (almost as if a patch), a zone a mesh with its wires running substantially at an angle with respect to the vertical and horizontal wires of the inner mesh “wrap”. These are outwards of each corner of any opening (e.g. doors or windows).
[0129] Preferably each corner is also further reinforced as additional reinforcement for, and/or support for, the plaster matrix, (almost as if a patch) a zone of a Rules mandated mesh between openings of close proximity (whether of same height or not). Preferably this is embedded in the base coat of the plaster system.
[0130] Preferably the first or inner mesh is a metal or wire mesh. It can be woven, forge knotted, welded or the like mesh or can be expanded perforate sheet material to define a “mesh”.
[0131] Preferably the outer or Rules mandated mesh is a non-metal mesh e.g. preferably fibreglass. Preferably that is a woven mesh.
[0132] Preferably external corners have a skeletal or lattice member embedded at least in part by the plaster matrix and embedded on both sides of the corner by the plaster matrix (eg. as if flanges).
[0133] Preferably the skeletal or lattice member is batten supported.
[0134] Preferably the external corner skeletal or lattice member is over the inner mesh.
[0135] Preferably the corner has acted as formwork.
[0136] Preferably said skeletal or lattice member is a corner moulding.
[0137] Preferably the external corner skeletal or lattice member is of a plastics material (eg. PVC).
[0138] Preferably window and/or door openings each have a head flashing to provide a canopy and that head flashing receives the inner mesh (ie. preferably holds the free ends of vertical wires of the mesh).
[0139] Preferably such flashings have end stopping (eg. flashing tape provided).
[0140] Preferably the flashings are of a plastics material (eg. PVC).
[0141] Preferably the head flashing is in part below the bottom ends of vertical battens and in part over a trim batten.
[0142] Preferably window and/or door openings have side jamb flashings.
[0143] Preferably each side jamb flashing locates a skeletal or lattice member (“side jamb skeletal or lattice member”) embedded at least in part by the plaster matrix.
[0144] Preferably each side jamb flashing is batten supported (at least in part).
[0145] Preferably each side jamb flashing is fixed to a trim batten or other batten.
[0146] Preferably window and/or door openings have a sill flange spanning between battens it is attached to.
[0147] Preferably a sill flashing (eg. of aluminium) overlays at least part of said sill flange.
[0148] Preferably the sill flashing is of “Z” section.
[0149] Preferably the sill flashing is of aluminium.
[0150] Preferably the sill flange has acted as a formwork periphery of the plaster matrix.
[0151] Preferably the top region of the sill flashing underlies the window frame (if opening is a window).
[0152] Preferably an inner mesh overlaps a flange of a wall bottom member (with preferably a drip edge).
[0153] Preferably the wall bottom member has two flanges, one to be positioned behind the bottom of vertical battens (and preferably to above any floor level) and one to be positioned over the same vertical battens and overlayed by the inner mesh.
[0154] Preferably the wall bottom member has acted as formwork for the plaster matrix.
[0155] Preferably the “Rules” hereafter described are or have been followed.
[0156] In another aspect the invention consists in a cavity wall type structure comprising:
a framing or a substructure, a paper or like wrap of such structure, battens supported from said framing or substructure but over said paper or like wrap, an inner metal mesh (preferably with its own paper) stapled or otherwise fixed to such battens, extra metal mesh attached to said battens and/or to the inner mesh outwardly of corners of openings, a second mesh (preferably a non-metallic mesh) as the (hereafter referred to as “outer mesh”) supported at least in part by a plaster matrix, mesh reinforcement (preferably a non-metallic mesh) of some regions with additional mesh as required by the Rules hereafter, and a plaster matrix that has been applied as more than one layer, at least one and preferably two layers having being applied prior to the association thereto of said outer mesh, the plaster matrix not showing any substantial amount of said outer mesh at the face surface to the outside of the building.
[0165] Preferably the plaster matrix is of at least a three layer application.
Preferably the inner metal mesh, extra metal mesh and the additional mesh reinforcement is in or to a base layer of the plaster matrix and the second mesh reinforcement is to a second layer of the plaster matrix.
[0167] In an aspect the invention is an in situ formed type stucco (ie. plaster matrix) panel of a building structure supported from cavity providing battens;
[0168] wherein the panel is supported (at least in part) from the battens by an embedded metal mesh (optionally and preferably of two layers in some areas) and the plaster matrix embeds, more outwardly than the metal mesh, another mesh (eg. of fibreglass) [optionally and preferably of two layers] in some areas;
[0169] wherein [optionally but preferably] the panel is about 21 mm thick;
[0170] and wherein the panel has no movement control joints;
[0171] and wherein the panel is of perimeter larger than 2.4 mm×4 m.
[0172] Preferably outwardly of corners of opening there is two layers of the metal mesh.
[0173] Preferably “Rules” as hereinafter described mandate use of an extra layer of the mesh more outwardly of the metal mesh and embedded into the base coat.
[0174] In still a further aspect, the invention consists in a building envelope having battens that support part or all of an in situ formed panel (preferably of about 21 mm thick);
[0175] wherein there is
an inner mesh attached to the battens, zonal reinforcement mesh outwardly of at least some corners of any openings in the panel, an outer mesh, different and/or same zonal reinforcement by a mesh, and a plaster matrix embedding all of the meshes; and wherein the outer mesh is of smaller opening size than both the mesh of the inner mesh and the zonal reinforcement mesh of each (or some) opening(s).
[0182] Preferably the Rules mandated mesh is of smaller opening size than the inner mesh.
[0183] In a further aspect the invention consists in a building envelope having battens that support part or all of an in situ formed panel (preferably of about 21 mm thick);
[0184] wherein there is
an inner mesh attached to the battens, zonal reinforcement mesh outwardly of at least some corners of any openings in the panel, an outer mesh different and/or same zonal reinforcement by a mesh, and a plaster matrix embedding all of the meshes; and wherein the outer mesh is of smaller opening size yet at least as flexible as the inner mesh and the zonal reinforcement mesh outwardly of each (or some) opening(s).
[0191] In a yet further aspect the invention consists in a building envelope having battens that support part or all of an in situ formed panel (preferably of about 21 mm thick);
[0192] wherein there is
an inner mesh attached to the battens zonal reinforcement mesh outwardly of at least some corners of any openings in the panel an outer mesh, different and/or same zonal reinforcement by a mesh, and a plaster matrix embedding all of the meshes; and wherein the Rules impose a mesh of smaller opening size than the inner mesh (or the inner mesh and the zonal reinforcement mesh outwardly of each (or some) corner(s)) for some spaces between openings (or elsewhere as the Rules mandate).
[0199] In yet another further aspect, the invention consists in a building envelope having battens that support part or all of an in situ formed panel (preferably of about 21 mm thick);
[0200] wherein there is
[0201] an inner mesh attached to the battens
zonal reinforcement mesh outwardly of at least some corners of any openings in the panel an outer mesh, different and/or same zonal reinforcement by a mesh, and a plaster matrix embedding all of the meshes; and wherein the perimeter of the in situ formed movement control jointed containing panel is other than square or rectangular; and wherein there is a Rule dictated movement control joint provided as a consequence of any significant departure of the square or rectangular perimeter.
[0208] In another aspect the invention consists in any of the assemblies, procedures, structures, NZ regulatory authority satisfying cavity wall stucco panels or the like substantially as herein described with or without reference to the “Rules” and/or with or without reference to any one or more of the accompanying drawings.
[0209] In a further aspect the invention consists in a building envelope having battens that support, part or all of an in situ formed panel of about 21 mm thick;
[0210] wherein there is
an inner mesh attached to the battens, a plaster matrix carried at least in part by the inner mesh and an outer mesh in turn supported, by embedment by the plaster matrix; and wherein any one or more of the preferments apply.
[0215] Preferably an envelope is further characterised in that the battens are supported from framing or a substructure.
[0216] Preferably that framing or substructure includes studs of timber, metal or other material.
[0217] Preferably the battens are fixed by penetrative fixers with preferably no fixing of the wire mesh is fully through a batten.
[0218] Preferably the panel reinforced by overlays of one or both the inner and outer mesh with further mesh reinforcing.
[0219] In another aspect the invention consists in a method of in situ formation of a reinforced plaster panel as cladding of a support structure, (eg. thereby to define a stucco type cavity wall structure) said method comprising or including the steps of
said fixing battens to the support structure, preparing for the panel creation
(A) by affixing a mesh (as an “inner mesh”) to the battens, and (B) providing prior to such affixing of the inner mesh, during the affixing of the inner mesh and/or after the affixing of the inner mesh, a periphery to co-act with the inner mesh as at least part of the formwork,
applying plaster into and onto the inner mesh and/or to or adjacent to the periphery to provide a base coat of plaster, after at least a partial set of the base coat, applying plaster onto the base coat as a second and levelling coat to the periphery, overlaying the second and levelling coat with a mesh (the “outer mesh”), by any suitable means (eg. trowelling and or otherwise) embedding or part embedding the outer mesh into the second and levelling coat, and applying a third plaster coat onto the second and levelling coat or the second and levelling coat and the at least partially embedded outer mesh; and wherein steps leading to any of the preferments are employed.
[0230] Preferably a building, cavity wall type structure, or stucco panel, of any of the previously defined or preformed forms is a result of such method.
[0231] The invention is also any product of such a method.
[0232] The invention is also, in combination, components suitable for or of any such product produced by such a method.
[0233] In another aspect the invention is a building structure comprising or including
framing of a pair of intersecting walls; battens outwardly (as herein defined with respect to internal or external intersections); a lower set of stucco panels cladding over some of the battens; a higher set of stucco panels cladding over some of the battens, there being a space defined between the lower and higher sets; and plural flashing members in and/or behind said space, including one flashing member that extends about the framing at the transition of framing for one of the intersecting walls to the other, in a mutual lapping condition flashing member to flashing member, affixed to the framing behind the lower regions of the higher set of panels and behind some of the battens, and extending over and down higher regions to the outside of the lower set of panels.
[0239] Preferably any one or more of the preferments herein referred to apply.
[0240] In still another aspect the invention is a building structure comprising or including:
framing of a pair of intersecting walls; battens outwardly (as herein defined with respect to internal or external intersections); a lower set of panels being of mesh reinforced plastered material(s), cladding over some of the battens and attached by the mesh at least to the battens and/or framing; a higher set of panels, being of mesh reinforced plastered material(s), cladding over some of the battens and attached by the mesh at least to the battens and/or framing, there being a space defined between the lower and higher sets; and plural flashing members in and/or behind said space, including one flashing member that extends about the framing at the transition of framing for one of the intersecting walls to the other, in a mutual lapping condition flashing member to flashing member, affixed to the framing behind the lower regions of the higher set of panels and behind some of the battens, and extending over and down higher regions to the outside of the lower set of panels.
[0246] Preferably any one or more of the preferments herein referred to apply.
[0247] In still another aspect the invention is a building structure of a stucco type comprising or including:
framing of a wall; battens on said framing; a horizontally spaced pair of in situ formed panels cladding over said battens on said framing, the pair of panels defining a vertical movement control joint wherein the vertical movement control joint is being a vertically extending space bounded by opposing edges of each panel, and a vertically extending flashing having
(i) a zone (“zone 1”) underlying, as a flange, each proximate edge region of a panel but over a said batten; (ii) a zone (“zone 2”) from each flange-like zone facing and/or keying to the edge of the panel; and (iii) a zone (“zone 3”) of allowing flexure horizontally between zones (i), zones (ii) or zones 1 and 2.
[0255] Preferably any one or more of the preferments herein referred to apply.
[0256] In yet another aspect the invention is a side jamb assembly of or for a peripherally framed glazed or glazable assembly of a stucco type structure, the side jamb assembly having:
at least one framing member vertically extending about the opening to be glazed and dressed; at least one batten vertically extending from said framing members; a first extruded flashing affixed to at least one batten to underlie in part behind an inserted, or to be inserted, peripherally framed glazed or glazable assembly, and a second extruded flashing outwardly of but extending laterally to the first extruded flashing, and affixed to at least one batten.
[0261] Preferably any one or more of the preferments herein referred to apply.
In still another aspect the invention is a sill flashed window or door assembly of a stucco type building structure:
[0263] wherein a “Z” type flashing has
an upper flange behind part of each side jamb flashing extending down towards the median part of the “Z” form; an upturn of each partly freed end region of the median part, rising as it extends rearwardly from the lower flange, to or towards the upper flange, and each such upturn is sealed to the upper flange.
[0267] Preferably any one or more of the preferments herein referred to apply.
[0268] In still a further aspect the invention is a head flashed window or door assembly of a building structure of a stucco type:
wherein there is a ‘Z’ type head flashing with its median part and lower flange at each end overlying a top part of a side jamb flashing; and wherein a flashing tape from (preferably under) the median part at each end of the ‘Z’ type head flashing is captured above the median part of the ‘Z’ type head flashing as at least part of a stop-end of an extruded still like drip edge extrusion as a flashing above both the median part and lower flange of the ‘Z’ type head flashing.
[0271] Preferably any one or more of the preferments herein referred to apply.
[0272] As used herein the term “and/or” means “and” or “or”. In some circumstances it can mean both.
[0273] As used herein the term “(s)” following a noun means one or both of the singular or plural forms.
[0274] As used herein “stucco” or “stucco panel(s)” includes (but is not limited to) any batten fixed mesh carrying a plaster matrix which itself embeds a mesh more outwardly of the batten fixed mesh, the panel(s) having been in situ formed to structure or frame carried battens.
[0275] Preferably regional reinforcement by one or both meshes being overlayed is provided.
[0276] As used herein the term “wrap” and related words) in respect of the first or inner mesh envisages, but is not limited to, discrete mesh expanses being placed (preferably with lapping) to provide an inner mesh support wheresoever there is to be the laying up of the plaster system.
[0277] As used herein “mesh” includes any lath or indeed alternatives such as any suitable perforate sheet. Preferably in respect of the batten fixed “inner” reinforcement it is of metal substantially as herein described. However in other variants it can be of, for example, stainless steel. The term “mesh” (or indeed the alternatives referred to) where not the batten fixed “inner” reinforcement or fixed regional reinforcement preferably is of a suitable glass or plastics fibre or at least derived from such materials (i.e. glass or plastics). In still other less preferred embodiments it can be of metal.
[0278] As used herein, the term “regional” means less than coextensive with the whole panel (minus openings). The preferred inner and outer reinforcements that are preferably so coextensive are “nonregional” in that sense.
[0279] As used herein “plaster” or “plaster matrix” can include (but is not restricted to) in the same panel, the same or different “plaster” for different layers of application.
[0280] For example MCL® Stucco Rite® System plaster mixes. Such as, in sequence, NZ660 Multicoat cement plaster (pumped, and trowelled only after outer mesh placement) and top coat layer NZ660 Multicoat cement plaster (hand skimmed) and sponge finish.
[0281] Alternatively, a water repellent plaster sealer may be applied as a seal to the second layer and a top coat of a finishing plaster applied [e.g. MCL® Stucco Rite® AL40 SP Polymer Modified Finishing Plaster.
[0282] A water repellent plaster sealer may be applied prior to full set. A final waterproof coating can be applied post set.
[0283] To those skilled in the art to which the invention relates, many changes in construction and widely differing embodiments and applications of the invention will suggest themselves without departing from the scope of the invention as defined in the appended claims. The disclosures and the descriptions herein are purely illustrative and are not intended to be in any sense limiting.
BRIEF DESCRIPTION OF THE DRAWINGS
[0284] One preferred form of the present invention will now be described with reference to the accompanying drawings in which
[0285] FIG. 1 shows in isometric a preferred moulding (or if an extrusion preferably with added machining) to provide for leakage bottom preferably with a drip edge (eg. as in our NZ Registered Design 408975),
[0286] FIG. 2 shows in isometric a moulding (or extrusion preferably optionally with machining) suitable for use for the window and door head, and which also provides a drip edge (eg. as in our NZ Registered Design 408975),
[0287] FIG. 3 shows a soffit or sill flange (eg. as in our NZ Registered Design 408977) able to be extruded,
[0288] FIG. 4 shows a jamb flashing able to be extruded (eg. as in our NZ Registered Design 408976),
[0289] FIG. 5 shows a vertical movement control joint extrusion (eg. as in our NZ Registered Design 408978),
[0290] FIG. 6 shows a preferred form of mesh to be used as the first or inner mesh, the mesh having a full or partial paper backing,
[0291] FIG. 7 shows a variety of horizontal movement control joints each in the form of a Z flashing and with complementary components able to accommodate for both external and internal corners of the outer cladding of the building envelope, FIGS. 60-72 show these components in more detail,
[0292] FIG. 8 shows a typical batten for use in the framing or substructure in accordance with the present invention, such battens for example being treated to H3.1 or H3.2,
[0293] FIG. 9 shows a typical framing radiata pine dwang treated to H3.1 or H3.2,
[0294] FIG. 10 shows a typical stainless steel ring grip nail (for example of 75 mm×2.8 mm diameter) for insertion into battens and/or framing components,
[0295] FIG. 11 shows a typical hot dipped galvanised round head nail (for example 20 mm×2.8 mm) used in some of the subassemblies or assemblies hereinafter depicted,
[0296] FIG. 12 shows a typical stainless steel staple (for example of at least 1.6 mm diameter) able to be used to locate the inner mesh to the dwangs,
[0297] FIG. 13 shows a typical flashing tape to be used,
[0298] FIG. 14 shows a typical silicone sealant dispenser,
[0299] FIG. 15 shows a typical wall wrap which can be used between the framing members and dwangs such as in FIG. 9 and the battens (such as shown in FIG. 8 ),
[0300] FIG. 16 shows the Z form flashings preferably of powder coated aluminium that can be used as head or sill Z flashings,
[0301] FIG. 17 shows a typical timber framing layout typically of double stud adjacent openings and with dwang spacings of 900 mm or less, typical dwang sizes being 45 mm×90 mm or larger with the stud sizes being complementary,
[0302] FIG. 17A shows nominal stud spacings of 600 mm, nominal dwang spacings of 90 mm centres and batten placement on each stud and midway (i.e. at about 300 mm) between studs.
[0303] FIG. 18 shows framing such as shown in FIG. 17 wrapped with the moisture barrier wall wrap of FIG. 15 , also showing the use of flashing tape about the openings,
[0304] FIG. 19 shows a concrete floor slab and its juxtaposition to the bottom member depicted in FIG. 1 ,
[0305] FIG. 20 shows a batten layout for a double level wall showing with the detailing head, from the top left in a clockwise sense, the sill detail, the head batten detail and the butt joint on a double dwang,
[0306] FIG. 21 is an elevational view detailing the positioning of the sill flange and its relationship to the sill Z flashing,
[0307] FIG. 22 details the side jamb flashing,
[0308] FIG. 23 shows the elevation of the head Z flashing in its subassembly,
[0309] FIG. 24 shows the soffit flange in elevation in its subassembly,
[0310] FIG. 25 shows in elevation where it is a movement control joints meets a horizontal movement control joint, the Z flashing extending horizontally,
[0311] FIG. 26 is a plan view of the vertical movement control joint and its relationship to the inner metal mesh, the outer fibreglass mesh, the plaster matrix and the battens,
[0312] FIG. 27 shows, to the bottom right of an opening, how sheets of inner mesh substantially as depicted are lapped and are fixed by staples to the underlying battens through the carried paper,
[0313] FIG. 28 shows some metal mesh, without the paper being used, as a zonal reinforcement overlay or reinforcement “patch” outwardly of the opening at each corner, such square mesh being laid diagonally in order to provide strength in directions other than primarily the vertical and horizontal, outer fibreglass mesh is then laid outwardly of the metal mesh.
[0314] FIG. 29 is a typical detail of the bottom of a door,
[0315] FIG. 30 shows an inner mesh and inner mesh corner reinforcement at the head of an opening,
[0316] FIG. 31 shows a similar arrangement for the bottom of an opening (in this case a window),
[0317] FIG. 32 shows a typical mesh to be used as the outer mesh (typically of fibreglass),
[0318] FIG. 33 shows a gun applying a second layer of plaster onto the first layer or base layer of plaster which has passed through the inner mesh and has attached at least in part to the inner mesh,
[0319] FIGS. 34A and 34B show the skeletal or lattice external corner members (eg. as in our NZ Registered Design Application 408974) positioned respectively to the top of the wall and to the bottom of the wall over the inner mesh,
[0320] FIGS. 34C and 34 D show the skeletal or lattice flange members positioned to the side of a window opening,
[0321] FIG. 35A shows the skeletal or lattice-like flange member (eg. of NZ408974) for use with each window and door opening,
[0322] FIG. 35B shows a jamb flashing (as in our NZ Registered Design Application 408976) able to locate and anchor one part of the skeletal or lattice flange of FIG. 35A ,
[0323] FIG. 36 shows the combination of the two components of FIGS. 35A and 35B with the flange toeing into and being kept located by a shoulder of the side jamb flashing, the lattice region of the flange being able to be fixed by nail into a batten,
[0324] FIG. 37 shows an exploded diagram able to explain spacially how various components cooperate when an opening is to be glazed,
[0325] FIG. 38 shows in part the application of a mesh, as shown in FIG. 2 , over part of the lattice region of the flange of FIG. 35A ,
[0326] FIG. 39 shows the location of the lattice flange of FIG. 35 relative to a sill of a window opening,
[0327] FIG. 40 shows a base coat plaster being applied and using in part the lattice region to the nose of the member of FIGS. 34A , 34 B and 35 substantially as both reinforcement and formwork,
[0328] FIG. 41 shows the trowelling in of the outer mesh (as shown in FIG. 32 ) subsequent to the application of the second coat shown being applied in FIG. 33 ,
[0329] FIG. 42 shows a plan view of the relationship of the components of the cavity wall system of the present invention,
[0330] FIG. 43 shows a vertical section of the detail shown in FIG. 42 ,
[0331] FIG. 44 shows in elevation the detailing with respect to a soffit,
[0332] FIG. 45 shows in more detail the arrangement previously shown in FIG. 19 ie. the concrete foundation and base detail,
[0333] FIG. 46 shows in plan the detail of an external corner, there being seen the lattice and nose providing corner member as shown in FIGS. 34A , 34 B and 35 ,
[0334] FIG. 47 shows an internal corner (ie. internal only in the sense that it is still part of the exterior of the wall structures), no similar (but complementary) lattice member to that as depicted in FIG. 34A , 34 B or 35 being necessary,
[0335] FIG. 48 shows head detail in elevation,
[0336] FIG. 49 shows sill detail in vertical section,
[0337] FIG. 50 shows jamb detail in plan,
[0338] FIG. 51 shows in vertical section the bottom of a door to deck with some sill detail,
[0339] FIG. 52 shows the bottom of a door to deck with flush detail,
[0340] FIG. 53 shows, in vertical section, a horizontal movement control joint between different wall levels (ie. its position optionally at an intermediate floor location),
[0341] FIG. 54 is a three dimensional view of a break away drawing of some features of the present invention,
[0342] FIG. 55 shows a vertical movement control joint meeting a horizontal movement control joint, all in vertical section,
[0343] FIG. 56 shows bottom drip edge detail to a flat roof wall, all in elevation.
[0344] FIG. 57 shows the plan section through a jamb to a typical door,
[0345] FIGS. 58 A through 58 MMM show diagrams and detail (herein incorporated as text hereof by reference) appropriate for application of certain rules (“Rules”) as to movement control joint (“MCJ”) location and extra fibreglass mesh reinforcement placement, such extra fibreglass being insertable by, for example, trowelling of it into an unset plaster layer, preferably the base coat layer.
[0346] FIG. 59A shows MCL® Stucco Rite® NZ660 multicoat cement plaster in 25 kg bags,
[0347] FIG. 59B shows MCL® Stucco Rite® A140 SP polymer modified finishing plaster in 25 kg bags & pre-mixed in plastic buckets,
[0348] FIG. 59C shows MCL® water repellent plaster sealer in plastic containers,
[0349] FIG. 59D shows MCL® fibreglass mesh 1×50 m rolls 160 grams per square metre,
[0350] FIG. 59E shows a MCL® uPVC Kwik™ corner,
[0351] FIG. 59F shows a MCL® uPVC Kwik™ flange for windows and doors,
[0352] FIG. 59G shows a MCL® Stucco Rite® mortar pump (G5C),
[0353] FIG. 59H shows a MCL® Stucco Rite® pump (Blitz),
[0354] FIG. 59I shows a MCL® Stucco Rite® Mortar Pump (Ritmo),
[0355] FIG. 60 shows a straight joiner moulding,
[0356] FIG. 61 shows a ‘Z’ flashing aluminium extrusion,
[0357] FIG. 62 shows a straight joiner moulding joining two ends of ‘Z’ flashing aluminium extrusions,
[0358] FIG. 63 shows a front view of the assembly of FIG. 62 , and shows the location of the cross section A-A,
[0359] FIG. 64 shows an end view of the assembly of FIG. 62 ,
[0360] FIG. 65 shows the cross section view A-A of FIG. 63 , and shows the location of the detail ‘B’,
[0361] FIG. 66 shows the detail ‘B’ of FIG. 65 ,
[0362] FIG. 67 shows a corner joiner moulding (as moulded), which is reversible to suit both external and internal corner configurations via the use of packers,
[0363] FIGS. 68A and 68B shows corner joiner packer mouldings which can be clipped into the corner joiner moulding of FIG. 67 for the external corner configuration,
[0364] FIG. 69 shows an external corner joiner assembly with packers clipped into place,
[0365] FIG. 70 shows an end view of the external corner joiner assembly of FIG. 69 ,
[0366] FIG. 71 shows an internal corner joiner assembly, no packers are required,
[0367] FIG. 72 shows an end view of the internal corner joiner assembly of FIG. 71 .
DETAILED DESCRIPTION OF THE INVENTION
[0368] The existing MCL StuccoRite® Cavity Wall Cavity System is a masonry cladding system incorporating a 35 mm vented cavity, comprising of special pre-papered steel mesh fixed to H3.1 treated timber battens, incorporating flashings for openings and penetrations, control joints, H3.1 treated fixing blocks, plus a proprietary cementitious render. The cladding system is installed on timber framing that complies with NZS3604 protected by a building wrap and protected by a building wrap and pre-qualified window sealing tape that complies with Table 23 of E2/AS1 and BQI interim Performance Standard BQI C4021*. The render is protected from the weather with a coating system complying with BQI interim Performance Standard C5031*.
[0369] In the opinion of BEAL, the MCL StuccoRite® Cavity Wall Cavity System (known as MCL StuccoRite®) and when installed according to the MCL StuccoRite Technical Manual dated January 2006, will meet the following performance requirements of the Building Code:
Clause B1—Structural Integrity (including to NZS3604: 50 m+wind speed) Clause B2—Durability Claims C—Spread of Fire (resistance) Clause E2—External Moisture
[0374] The present invention is an evolution of that system.
[0375] The current system of the invention comprises proprietary plaster, reinforced with pre-papered hot dipped galvanised zinc steel wire MCL® StuccoRite® Mesh Sheet and other reinforcement, to achieve a nominal thickness of 21 mm with a standard sponge or plastic float finish. The plaster is applied by MCL® StuccoRite® Mortar Pumps over the mesh which is stapled to 35 mm×40 mm nominal sized H3.1 or H3.2 treated vertical timber battens providing a ventilated and drained cavity.
[0376] The proprietary plaster is applied in three coats; a base coat, a levelling coat, and the top coat. The base coat encapsulates the pre-papered MCL® StuccoRite® Mesh Sheet reinforcement as well as additional reinforcement at corners and around joinery. The levelling and mesh coat contains further reinforcement in the form of fibreglass mesh (MCL® Fibreglass Mesh).
[0377] The final skim coat is sponge or plastic float finish.
[0378] The MCL® StuccoRite® Mesh Sheet is fabricated from copper bearing cold drawn hot dipped galvanised zinc vertical face wires and horizontal back wires, electrically welded at all points of intersection. The zinc coating is not less than 27.9 g/m 2 .
[0379] The face and back wires are 1.5 mm diameter with openings not exceeding 51 mm. A layer of absorptive, slot perforated paper is placed between the face and back wires. The mesh is self furring by being fabricated horizontally into the lath at 152 mm centres with a 6.5 mm crimp in each face wire at its intersection with double back wires. A layer of Type 1, Grade D, Style 2 black building paper in compliance with UBC Standard No. 17-1 is strip glued to the back of the high absorbent slot perforated paper and is extended 100 mm beyond the lath at the left end of the sheet and 100 mm beyond the upper long edge of the sheet.
[0380] Reinforcement at all external corners is provided by MCL® uPVC Kwik corners being a 55 mm×55 mm angle with nosing and MCL®uPVC Kwik flanges, being 65 mm×15 mm angles with nosing, provide reinforcement at window and door openings.
[0381] MCL®Fibreglass Mesh is contained locally at certain openings in the base coat and continuously in the levelling and mesh coat. The MCL®Fibreglass Mesh is alkali resistant and woven with a 4 mm×4 mm aperture weighing not less than 165 grams per square mere.
[0382] The edges of the plaster are formed and supported by a number of uPVC mouldings. The MCL® Bottom J-Mould with Drip Edge and the MCL® Window/Door head with Drip Edge also provide vermin proofing and allow for drainage and ventilation to the cavity.
[0383] Movement is accommodated by providing physical breaks in the plaster. This is achieved with a uPVC moulding for the vertical movement control joint (VMCJ) and with a uPVC window head moulding and Z flashing for the horizontal movement control joint (HMCL).
[0384] Joinery shall comply with the requirements of E2/AS1 and be flashed with head and sill Z flashings as described in this Appraisal.
[0385] To provide a moisture resistant surface the completed plaster is sealed with the MCL® Water Repellent Plaster Sealer. The MCL® StuccoRite® System is completed by being waterproofed with the application of not less than a 2 coat paint system in accordance with Paragraph 9.3.7 of E2/AS1.
[0386] Components and consumables of the new system are preferably:
[0000] Battens—No. 1 framing, rough sawn or gauged 35 mm×40 mm Radiata Pine treated to H3.1 or H3.2.
Tolerance shall be + or −3 mm on both dimensions.
No. 1 framing Radiata Pine dwangs treated to H3.1 or H3.2. Minimum gauged 45 mm×90 mm.
Wall wrap complying with Table 23 of E2/AS1.
Flashing tape complying with Paragraph 4.3.11 of E2/AS!.
Powder Coated Aluminium Z flashings at head and sill of joinery.
Plain Aluminium Z flashing at garage door heads.
Mesh staples to the battens shall not be less than 1.6 mm diameter, 38 mm×9.5 mm or wider type 304 stainless steel gundriven divergent point staples.
Batten nails shall be not less than 75 mm long×2.8 mm diameter ring grip 304 stainless steel gun driven nail.
20 mm×2.8 mm diameter hot dipped galvanised round head nails.
Sealant to soffit, window/door jambs, HMCJ jointers and corners, meter box and all penetrations as per Paragraph 4.5.2 (g) of E2/AS1 which is a neutral cure silicone sealant.
At meter boxes 20 mm×20 mm×0.75 mm aluminium angle.
At decks:
M12 bolt with nut and washers; all Type 304 stainless steel length to suit.
50 mm×50 mmsq.×3 mm washer with 14 mm diameter hole, Type 304 stainless steel. 50 mm×50 mm sq.×3 mm EPDM washer.
10DN PVC Sleeve 22 mm long.
Saddle flashings as described in NZS 3604 and E2/AS1 can be used but to the dimensions described herein. Flashing material shall comply with Clause 4.10.2 of NZS 3604 or the ‘50 year’ requirement of Table 20 in E2/AS1.
Proprietary Type 304 Stainless Steel Joist Hanger minimum shear strength half span x spacing×3.35 kn (for 2.0 kpa Deck) or 4.85 kpa (for 3.0 kpa Deck)
140 mm×140 mm sq.×13 mm fibre cement board with 14 mm diameter hole.
Aluminium Z Flashings and uPVC Mouldings
MCL® Plain Aluminium deck and HMCJ Z flashings including uPVC Jointers and Corners to the HMCJ Z flashings all as described in the Technical Manual.
MCL® uPVC Bottom J-Mould with Drip Edge
MCL® uPVC Window/Door head with Drip Edge
MCL® uPVC Soffit/Sill Flange
MCL® uPVC Side Jamb Flashing
MCL® uPVC Vertical Movement Control Joint
Plaster and Sealer:
[0387] MCL® StuccoRite® NZ 660 Multicoat Cement Plaster (25 kg bags)
MCL® StuccoRite® AL 40 SP Polymer Modified Finishing Plaster (25 kg bags and pre-mixed in plastic buckets).
MCL® Water Repellent Plaster Sealer in plastic container.
Reinforcement
[0388] MCL® StuccoRite® Mesh Sheets by K-Lath Division of Tree Island Steel Inc, Monrovia California Fed. Spec. QQ-L-10c. (2.180 m×0.7 m)
MCL® uPVC Kwik Corner Reinforcing
MCL® uPVC Kwik Flange Reinforcing
MCL® Fibreglass Mesh with 4 mm×4 mm apertures and weighing 160 g/sqm (1 m×50 m rolls).
The MCL® plaster shall be mixed with potable water and applied to walls by a MCL® StuccoRite® Mortar Pump. These electric powered rotor/stator pumps are as shown in the Technical Manual and are supplied for purchase or hire by MCL®.
[0389] Materials for use as the plaster system are available from Mineral Coatings (NZ) Limited.
[0390] The MCL® StuccoRite® System requires a continuous concrete foundation or slab edge thickening under all walls.
[0391] The MCL® StuccoRite® System is intended to be fixed to timber walls with studs at 600 mm centres, heights up to 4.8 m and dwangs spaced at up to 900 mm centres. An additional dwang is required at soffit level as described in the Technical Manual.
[0392] The system is able to resist wind face loading up to and including those associated with VH wind speed zones.
[0393] The weight of the total system is 41 kg/m 2 and does not contribute to the building lateral bracing.
[0394] The system may be fixed to wet timber framing provided the interior lining and insulation is not installed until the framing moisture content is less than 18%.
[0395] The location of Movement Control Joints (VMCJs) shall be shown on the consented building elevations in compliance with the Rules.
[0396] Vertical Movement Control Joints (VCNJ's) shall be provided at changes in elevation, at openings and to break the length of a wall into sections no wider than 8 meters or 2.75 times the panel's height all as required by the Rules hereafter. Where VMCJ's are required they shall not be located any closer than 175 mm to any penetrations including those for windows or doors.
[0397] Horizontal Movement Control Joints (MMCJ's) shall be provided at intermediate floor level where the moisture content of flooring timbers or wall plates abutting the intermediate floor is greater than 18%. Checks on moisture content shall be conducted prior to plastering commencing to ensure this requirement is met.
[0398] Where battens extend continuously past an intermediate floor (i.e. with no provision for a HMCJ) and checks before plastering reveal a moisture content higher than 18% then either the wall shall be re-battened allowing for the provision of a HMCJ at intermediate floor level or plastering operations shall be delayed until such time as the moisture content has dropped to 18% or less.
[0399] In addition to any HNCJ that may be required at the intermediate floor level, HMCJ's shall be provided at horizontal steps and to break the height of the wall into panels with a maximum average height of 5 meters except at gable ends and other certain narrow panels all as required by the Rules hereafter. Where HMCJ's are required to limit height they shall be located at an intermediate floor as shown herein.
[0400] The MCL® Stucco Rite® System allows for the construction of decks, simply supported or cantilevered. The requirements of NZS 3604 must be followed except to extent required to account for the junction.
[0401] Whilst specific materials have been specified for various employments herein, various consumables in so far as the reinforcement attachment and building up the matrix, a person skilled in the art will appreciate other alternatives that might exist Likewise in respect of any weather proofing of the plaster matrix other options to those described or described in the aforementioned website can be used.
[0402] FIG. 1 shows a preferred bottom member 1 preferably of a small uPVC and having two main flanges and a drip edge as well as openings 1 A for moisture drainage purposes.
[0403] FIG. 2 shows, similarly of a uPVC material, a member able to act as a window and door head. This member 2 also has a drip edge feature 2 A and moisture drainage openings 2 B for use in the assembled condition shown in FIG. 55 as an example.
[0404] FIG. 3 shows a soffit and sill flange 3 , preferably also of uPVC.
[0405] FIG. 4 shows a member 4 which can act as a jam flashing. This also is preferably of uPVC.
[0406] FIG. 5 shows a preferred member, preferably also of uPVC, able to be used to provide a vertical movement control joint. This member with its bellows like central region and its two flanges (each with openings to facilitate water migration and/or fixing) is used in the manner as shown in FIG. 26 .
[0407] FIG. 6 shows MCL® Stucco Rite® zinc coated mesh sheet typically of 2.180 m×0.7 m double wire. This wire mesh is used as the inner mesh 6 and is laid with overlapping over battens 8 to be stapled by staples 12 .
[0408] The same mesh, without the paper backing shown in FIG. 6 , can be used for the reinforcement requirements at the corners herein described. These reinforcement members 23 likewise can be stapled to battens or can be tied to the existing mesh 6 , or both.
[0409] FIG. 7 shows aluminium control joint members showing assemblies of corner elements with straight flashing portions. The Z form flashing members 7 are used as part of the horizontal movement control hereinafter described. Shown as 7 A and 7 B respectively are assemblies of such components for use on an inside exterior corner and an outside exterior corner respectively.
[0410] FIG. 8 shows a typical rough sawn treated batten as foresaid typically 35 mm by 40 mm.
[0411] FIG. 9 shows a typical dwang component 9 preferably of minimum size 45 mm by 90 mm for use with the framing (typically shown in FIG. 17 ).
[0412] FIG. 10 shows a typical nail 10 that can be used in the system to secure battens to the under lying building structure or wooden frame such as shown in FIG. 17 .
[0413] FIG. 11 shows nails 11 able to be used to secure some of the flashing components and other components as hereinafter described.
[0414] FIG. 12 shows a staple 12 able to be used to secure the mesh 6 to the underlying battens 8 as hereinafter described.
[0415] FIG. 13 shows flashing tape 13 used, for example, in a manner shown in FIG. 18 in connection with the wall wrap 14 .
[0416] FIG. 16 shows powder coated aluminium head and sill Z flashings 15 used as hereinafter described.
[0417] FIG. 17 shows, by way of example, a simplified frame of studs, paired about openings and provided with appropriate dwangs.
[0418] Preferably the studs are at 600 mm centres or less.
[0419] Preferably the gaps between bottom plates and dwangs and between dwangs is a maximum of 900 mm.
[0420] The underlying frame as shown in FIG. 17 is then wrapped with the wrapping material 14 as already used in the Stucco Rite® system. The flashing tape 13 is applied as shown about a window opening 16 and door opening 17 .
[0421] Battens 8 are then applied over the surface. These battens are shown over the wrap as shown in FIG. 8 . Battens are paired alongside openings and are elsewhere spaced vertically such that there is a batten to all studs and in between. The maximum batten spacing is 300 mm.
[0000] The batten fixing with nails 10 is shown in FIG. 20 for a two level structure, the transition between the two levels being shown.
[0422] The construction method is preferably as previously stated. This results in a bottom panel near a foundation or concrete slab 18 having a batten 8 nailed by nails 10 into a floor plate on the slab 18 with building paper 14 interposed. A bottom member 1 as in FIG. 1 is located with its flanges as shown in FIG. 19 and nailed by nails 11 to the floor plate. In turn the inner metal mesh 16 is fixed to the battens 18 by staples 12 thereby to allow a sequence of applications of plaster to provide the build up of a plaster matrix 20 (preferably of three layers) which also embeds the fibreglass mesh 19 .
[0423] FIGS. 21 and 22 shows similar arrangement for the use of a sill flange and the side jam flashing.
[0424] In FIG. 21 the steam attached to a batten by nail a sill flange 3 and in turn its been overlayed so as to provide a canopy effect by a head flashing 15 or 7 .
[0425] FIG. 22 shows in plan a double batten arrangement 8 into a double stud arrangement about a window or door opening. Shown is a lattice like member 21 toed as in Figure?
[0426] In FIGS. 35A to 36 show the side jam flashing 4 , the lattice providing member 21 (preferably also of a PVC material) to be used in position substantially as shown in FIGS. 38 and 39 . Shown in part in FIG. 38 is the outer mesh 19 overlying the lattice type member 21 .
[0427] With reference to FIGS. 35 to 36 jamb flashing 4 may be installed flush with the inner window trim edge. The window flange 21 can then be fitted, by clipping the window flange 21 into the vertical groove of the jamb flashing 4 . Nails/clouts 11 can then be used to fasten the window flange 21 in place.
[0428] FIG. 37 shows in respect of an opening how a side jam member 4 is to be used to underlie the canopy of the to be fitted head flashing 7 . This position alongside an opening and to battens subsequently enables lattice member 21 to be toed in for nail fixing.
[0429] Incidentally FIG. 37 shows bevelled battens 8 to allow both the top 13 (and the end-stop tape 13 A) and the top region of flashing 7 under the battens 8 .
[0430] Later drawings show other preparative arrangements and the resultant stucco panels.
[0431] A feature that enables the satisfying of likely regulatory requirements for such larger size panels (albeit nominally of 21 mm thickness) is all as shown. A major requirement is not to take panels beyond an approved size without moving control joints or by satisfying the reinforcement requirements (that preferably involves the use of an extra amount of mesh as dictated by the Rules hereinafter described) and the movement control joint requires (also as dictated by the Rules).
[0432] FIG. 44 shows soffit 25 positioned relative to an underlying panel of the system, the soffit 25 being overlayed by a timber member 35 .
[0433] FIG. 51 shows flooring 30 over blocking 31 in relation to an in situ formed panel. FIG. 52 similarly but note the set down option.
[0434] FIG. 53 shows a HMCJ below flooring 30 and a joist 32 . Shown is a top plate 33 and a stud 26 . Also a bottom plate 34 .
[0435] The bevelling of battens 8 can be seen in a number of locations to accommodate flashing taped flashings.
[0436] The usual method of construction can be seen by reference to our website mentioned previously.
[0437] Shown, by way of example, in FIG. 1 is an already applied basecoat A over and through the mesh 6 and any additional regions of mesh 23 as mandated outwardly of each corner.
[0438] The second layer B is being shown applied in FIG. 3 and this is the region on to which mesh 19 is positioned and trowelled in as shown in FIG. 41 .
[0439] Any extra mesh material (e.g. of preferably a similar type to 19 ) mandated by the Rules is positioned on or applied into the base layer A (e.g. by a similar technique to that shown for mesh being positioned into layer B). This is in addition to the mesh 23 requirements.
[0440] Once the mesh impregnated layer B has been smoothed the third coat can then be applied thereby to leave the plaster matrix ready for finishing in a manner as previously described. For example any suitable preset/post set water repellent/resistance coating system.
Rules for MCJ Location and Fibreglass Mesh Reinforcing
[0441] For the purpose of these Rules the alphanumeric and numeric content of the appended drawings is here included by reference.
[0442] The location of movement control joints, both vertical (VMCJ) and horizontal (HMCJ), and additional Fibreglass Mesh into the basecoat, all is required by these Rules, shall be shown on plans and specifications.
[0443] With stucco extending vertically from the base of the wall (i.e. bottom member of FIG. 1 ) to the top of the wall (i.e. soffit flange shown in FIG. 44 ) and horizontally between external or internal corners (see FIGS. 46 and 47 ) it shall be divided (where size of panel dictates) into wall panels by means of horizontal (HMCJ) and vertical (VMCJ) control joints (see FIG. 25 and FIG. 26 ) as required by the following Rules.
[0444] The width and average height of a wall panel shall be measured between the control joints or the stucco edges (base soffit or internal/external corners) that bound the wall panel.
[0445] For the purposes of these Rules the locations and dimensions of the “openings” shall be measured to the plasters' edge.
[0446] Rule 1 A VMCJ, as required by these Rules, shall extend from the bottom member of FIG. 1 or a HMCJ of FIG. 25 up to the soffit or upper HMCJ. A HMCJ shall extend the full width of the wall panel and around internal or external corners along the adjacent wall panel to a VMCJ. A HMCJ does not have to extend beyond a VMCJ.
[0447] Rule 2 A VMCJ is required:
a) At each end of all openings wider than 3 m or higher than 1.95 m. the VMCJ's shall be placed no further than 300 mm from each side of the openings except a VMCJ is not required if the openings is closer than 600 mm from an internal or external corner or when Rule 10 applies. b) At a change in wall heights except as allowed by c) below. c) Where a change of direction occurs in either the top or bottom of the MCL®Stucco Rite® wall panel and the angle between the panel surfaces, as shown in the figures below, is less than 135°. A vertical offset (angle is 90°±20°) up to 600 mm long does not require a VMCJ.
VMCJ required at the locations shown in broken lines in each of FIGS. 58A to 58D . FIGS. 58A and 58B is for vertical offset lower and upper edge where height greater than 600 mm. FIGS. 58C and 58D were offset lower and upper edge at angle between surfaces less than 135°.
[0451] Rule 3 Install a HMCJ at any horizontal step in a wall panel where the width of the step is wider than 600 mm. For steps less than 600 mm embed a 400 mm square of fibreglass mesh in the basecoat diagonally across the step.
[0452] Rule 4 HMCJs shall be provided at intermediate floor level where, at the time of plastering, the moisture content of flooring timbers or wall plates abutting the intermediate floor is greater than 18%. In addition, HMCJs at intermediate floor level shall be provided where necessary to ensure the requirements on panel height are met.
[0000] The maximum average height of a MCL® Stucco Rite® wall panel shall be 5.2 m except in the following situations where the maximum height of the wall panel shall be 7 m:
a) Panels wider than 2.5 m and less than 6 m with a monoslope top edge of angle greater than 11° from the horizontal, and b) Panels wider than 4, and less than 8 m with sloping top surfaces of angle greater than 11° from the horizontal forming a gable with the apex located within the middle third of the panel width. c) The Z-Flashings below a cantilevered timber deck, as required by on page and shown on drawing is also a HMCJ.
[0456] Rule 5 Not withstanding the above Rules, the maximum width (L) of a wall panel shall not be greater than 2.75 times its height or 8 m.
[0457] Rule 6 A minimum separation distance of 175 mm shall be provided between the following:
a) VMCJ's and openings b) VMCJ's and corners (internal or external) c) VMCJ's d) Openings e) Openings and corners (internal or external) f) Corners (internal or external)
[0464] In all situations above where the separation distance is less than 300 mm provide a layer of fibreglass mesh in the basecoat over the full length of the separation distance. Where the separation distance is at an opening extend the mesh 300 mm beyond each end of the opening. See FIG. 58E onwards.
[0465] If the separation between openings is not horizontal or vertical but instead at some angle then the layer of fibreglass mesh in the basecoat shall extend out perpendicular to that angle, in both directions, over the full width of the separation for a distance of at least twice the separation distance. See FIG. 58E onwards (particularly FIGS. 58H to 58I ).
[0466] Rule 7 When the sum of the opening heights (Σh) in a wall panel exceeds 40% of the wall panel's average height (H) then reduce the wall panel's width to not greater than 6 m. When determining the sum, openings separated horizontally by 900 mm or less shall be included as shown in FIG. 58E onwards.
[0467] Rule 8 When the ratio Σh/H as determined by Rule 7 exceeds 80% of the wall panel average height then in addition to meeting the Rule 7 a VMCJ shall be provided no further than 300 mm from each side of all openings. A VMCJ is not required if the opening is closer than 600 mm from an internal or external corner or when Rule 10 applies. See FIGS. 58H to 58I ).
[0468] Rule 9 When the sum of the opening widths (Σb) exceeds 60% of wall panel width (L) then a layer of fibreglass mesh embedded in to the basecoat, shall be provided between all openings between openings and the panels edges extending from 300 mm above to 300 mm below he openings. When determining the sum, openings separated vertically by 900 mm or less shall be included as shown in FIG. 58E onwards (particularly FIGS. 58K to 58M ). This mesh is not additional to that required by Rule 6.
[0469] Rule 10 If the distance between two openings is 1.2 m or less than two MVCJ's between the openings may be replaced by one centrally located VMCJ.
[0470] In respect of FIGS. 58E to 58M the following is the key:
[0000]
L = width of MCL ®
H = average Panel
MCL ® Fibre Mesh in
Stucco Rite ® Wall
Height
base coat extending
Panel
Σb = Sum of Opening
300 mm above and
Σh = sum of Opening
Widths
below opening
Heights
b 1 b 2 = opening widths
h 1 h 2 = opening heights
[0471] In FIGS. 58 N to 58 KK are shown examples for MCJ and mesh location on single level buildings. In these drawings the key is as follows:
[0000]
L = Width of MCL ®
R = Rise of Gable
MCL ® Fibre Glass
Stucco Rite ® Wall
B = Opening width −
Mesh in base coat
Panel
Single Level
extending 300 mm
H = Average Panel
Σb = Sum of Opening
above and below
Height
width
opening
H′ = Lower Panel
b′ = Opening width −
* = CMCJ's required
Height
lower level
by Rules 2 or 8 and
H″ = Upper Panel
b″ = opening width −
placed at min
Height
Upper Level
separation distance
h = opening heights −
He - Eaves Height
i.e. 175 mm
single level
VMCJ or HMCJ -------
* = CMCJ's required
Σh = Sum of
Floor/Wall Junction
by Rules 2 or 8 and
Opening Heights
—
placed at max
h′ = Opening Height −
separation distance
Lower Level
i.e. 300 mm
h″ = Opening Height −
Upper Level
[0472] In FIGS. 58 LL to 58 MM are shown examples for MCJ and mesh location on two level buildings. In these drawings the key is as follows:
[0000]
L = Width of MCL ®
R = Rise of Gable
MCL ® Fibre Glass
Stucco Rite ® Wall
B = Opening width −
Mesh in base coat
Panel
Single Level
extending 300 mm
H = Average Panel
Σb = Sum of Opening
above and below
Height
width
opening
H′ = Lower Panel
b′ = Opening width −
* = CMCJ's required
Height
lower level
by Rules 2 or 8 and
H″ = Upper Panel
b″ = opening width −
placed at min
Height
Upper Level
separation distance
h = opening heights −
He - Eaves Height
i.e. 175 mm
single level
VMCJ or HMCJ -------
* = CMCJ's required
Σh = Sum of
Floor/Wall Junction
by Rules 2 or 8 and
Opening Heights
—
placed at max
h′ = Opening Height −
separation distance
Lower Level
i.e. 300 mm
h″ = Opening Height −
Upper Level
[0473] The present invention has been described by reference to the drawings and requirements that might satisfy New Zealand regulatory approvals. Whilst the description is in respect of a wooden framed structure having a cavity depth of about 35 mm clad by a reinforced and weather sealed plaster matrix of about 21 mm thick, variations that might satisfy requirements in other countries are within the scope of the present invention. Reference is drawn to our website www.mineral.co.nz/stuccorite.cfm which discloses details of the existing MCL StuccoRite cavity wall cladding system described in our Technical Manual dated January 2006.
[0000] Some features of note in the new system include:
Stucco Panel
[0000]
Pumped in mortar to mark face
Bagged dry-mix—consistent high quality mix design and consistency
Lower water/cement to achieve lower shrinkage
Fibreglass mesh standard in top coat
Square of fibreglass mesh diagonal in top coat across corners of openings
Additional fibreglass mesh in base coat of narrower stucco panels located between larger stucco panels
Max panel size 8 m×5.2 m
Mesh
[0000]
K-Lath mesh is stapled to batten, not timber framing
Mesh can span up to 460 mm 16 g wire to 300 mm system or up to 640 mm with 149 g wire.
Built in plastering paper
Built in backing bituminous paper
Supplied and fixed as sheet with overlap of mesh and bituminous paper on two edges
Batten
[0000]
Vertical timber batten is structural size and enhances strength and strength of wall
Batten placement at 300 mm spacings fixed not only to stud face but can span up to 1.2 m between dwang to plates
Battens can span over floor/walls junction
HMCJ
[0000]
Spaced up to 5 m centres (instead of 2.4 m)
Special PVC z-flashing
Special PVC z-flashing splice and corner jointers
If z-flashing not nailed to batten then is replaceable due to taper at back of vertical batten
Can be located at
floor/wall junction window head any locations on timber framed wall
[0497] VMCJ
Spaced up to 8 m apart instead of 4 m Not located at side of openings Can be located as close as 175 mm to side of openings or corners No VMCJ at top corner of openings No VMCJ at bottom corner of openings Shrinkage absorbed by rolling/deflection of the batten
Special uPVC Profiles
Special pvc moulding for base of stucco wall panel incorporating batten, insert, drip edge Special pvc moulding for window head and VMCJ Special pvc moulding for window/door side jamb—two piece Special pvc moulding for soffit, sill and edge Special pvc moulding for VMCJ Fully waterproof moulding Accepts shrinkage or expansion Does not require double studs at VMCJ Does not even require any stud at VMCJ
[0513] Compliance with the Rules as set out we believe will enable compliance with both building code NZS3604 and plaster code NZS4251.
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A building which has as a wall of its envelope, a wall of a size of at least 2.4 m high, and at least 4 m wide; wherein the wall has a frame or a substructure having studs at least some of which are spaced by a modular distance, battens supported from and fixed to said frame or substructure, such battens fixed both on and between studs, a first mesh (“inner mesh”) attached to such battens, a second (“outer”) mesh supported at least in part by a plaster matrix, and the plaster matrix applied as more than one layer, the plaster matrix penetrating the first mesh, interposing both meshes, attaching to the second mesh and covering the second mesh; wherein the wall has at least one opening selected from a group consisting of door and window openings; and wherein at least part of the periphery of each opening, within the matrix, has been further reinforced by one or more of (a) one or more of at least one mesh and/or lattice-work at each corner, (b) one or more of at least one mesh and/or lattice-work at each vertical side, and/or one or more mesh between adjacent openings.
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FIELD OF INVENTION
[0001] The present invention is related to video game applications in general and video game applications where virtual characters evolve as they interact with a large number of players in particular.
BACKGROUND
[0002] When fighting and defeating a villain or monster requires a set number of techniques or attacks, a player may lose interest in the game. Predictability in how a virtual character behaves and how it is defeated also encourages a sort of cheating whereby a player can go online (e.g. to YouTube) and see how other players have defeated the villain, and then the player can repeat the same techniques in the game to defeat the said villain.
[0003] Additionally, when repetitive and mindless activities like farming and mining are needed, players may get bored or may have other players perform that activity for them. Similarly, when defeating a boss/monster/enemy is repetitive it takes away from the fun of playing the game and the players do not get the same sense of achievement as when defeating a unique and difficult to beat enemy. For example, in certain existing games, an attack move by a player may inflict 10 damage points to the villain. If the villain has 100 health/life points, then 10 such moves by the player can effectively defeat the villain. This makes the game predictable, repetitive and boring while taking away from the challenge.
[0004] A virtual world is a computer simulated environment. A virtual world may resemble the real world, with real world rules such as physical rules of gravity, geography, topography, and locomotion. A virtual world may also incorporate rules for social and economic interactions between virtual characters. Players (users) may be represented as avatars, two or three-dimensional graphical representations. Virtual worlds may be used for massively multiple online role-playing games, for social or business networking, or for participation in imaginary social universes.
[0005] Prior art virtual worlds present a static experience when engaging in gameplay. By overcoming these limitations, the present invention allows for a richer and more unique gameplay experience for each player.
SUMMARY OF THE INVENTION
[0006] It would be desirable to have a gameplay whereby the virtual characters evolve based on their interaction with different players, allowing virtual characters to learn from their recent defeats and vary their techniques so that the next player who happens to have an encounter with the virtual character cannot defeat it using the same technique that was used last time to defeat it.
[0007] In one embodiment of the invention, the game may start with a “string-set” that may contain more than one string to emulate different behaviors for the same virtual character. For example different strings like Easy, Medium and Hard for a monster (villain, boss, enemy, arch-nemesis etc.) may compose the string set at the beginning. Thus the monster may variably exhibit different levels of challenge required to defeat it using a different string. As more players interact and try to defeat the monster, it learns from the techniques of the players and mid-session may combine components from different strings in its string set. For example components from the Easy string may be combined with the components of a hard string. Thus the resultant behavior of the monster is different since now it has the combined characteristics of two different strings. This new string is now also added to the earlier string set. Thus next time when combining characteristics this new string may also be used along with the previous strings in the string set. Thus as more time goes by, there are more strings to choose from when an alternate behavior for the virtual character (monster, boss, villain, hero etc.) is required. This ensures that no two players when interacting with the same virtual character (villain or other) will have the exact same experience, therefore essentially requiring different techniques to defeat the same virtual character. This will also be true when the same player encounters the virtual character on two different occasions, either in the same level or on different levels of the game.
[0008] This application describes systems and methods whereby the virtual characters in a virtual world may change based on the interactions with real world players. Thus the more players interact with the virtual character, the more sophisticated it becomes as it learns and morphs with each interaction. This provides for a richer gaming experience and increases player engagement while making the gameplay of the virtual world more unique for each player. The systems and methods described here enable a player to have a unique and more enjoyable gaming experience.
[0009] According to a first aspect of the invention, a computer-implemented method is provided for providing virtual gameplay on a computing device in communication with a storage means. Access is provided to a video game in which players are able to interact via characters and each character behaves according to a series of scripts in a script set. A first player character is monitored as it interacts with a second character in the video game and the second character responds according to a script in its script set. Upon the first player character exhibiting repetitive behaviour in the interaction that causes damage to the second character that exceeds a preset damage threshold, the second character's script is changed. The changed script is stored on the storage means for future use.
[0010] Both the first player character and the second character can be player characters or non-player characters. In a preferred embodiment, the first player character is a player character and the second character is a non-player character (i.e. not under the direct control of a human player). However, it will be appreciated that even player characters can behave (at least in part) according to scripts, and the method can also be appropriate (with modifications as needed) where the second character is a player character.
[0011] In one embodiment, changing the script includes replacing the script with another script from the script set. For example, the replacement script may be replaced by a script for a higher level than would otherwise be default.
[0012] In one embodiment, each script has at least two sub-components. In this case, changing the script may include combining or replacing at least one of the sub-components with sub-components from another script in the script set. Preferably, each sub-component includes at least one statistic. The statistic may be a primary statistic or a derived statistic. Changing the script can also include changing the formula or algorithm by which a derived statistic in the sub-component is derived.
[0013] In another embodiment, changing the script includes combining or replacing the script with a script that has been downloaded, transferred, purchased, gifted, won, or lost, or restored or linked from another game. Any of the foregoing steps can be initiated by the player/user or the system (as appropriate according to the method, or as triggered by a behavior(s) of the player/user).
[0014] After the script is changed, the first player character is preferably allowed to continue the interaction with the second character with the changed script invoked. In this case, the second character will behave according to the changed script. For example, the second character may be detectably strengthened by invocation of the changed script. Or, for example, the second character may be detectably faster by invocation of the changed script. In another embodiment, invoking the script may result in the second character having at least one non-default move, attack or defence, and/or at least one non-default tool or weapon (including, armour, property, gold, etc.). In another embodiment, the second character may have detectably increased health or life by invocation of the changed script.
[0015] Various configurations of storage are possible. Preferably, the storage means is provided by one or a combination of: a local fixed memory, a local removable memory, a remote fixed memory, a remote removable memory, and a virtual memory.
BRIEF DESCRIPTION OF THE FIGURES
[0016] FIG. 1 is a flow diagram illustrating the primary steps of the method, according to a preferred embodiment.
[0017] FIG. 2 is a flow diagram illustrating an ongoing process for evaluating repetitive and damaging moves to trigger evolving a virtual character by changing strings.
[0018] FIG. 3 is an illustrative notional data structure showing statistics of a virtual character and possible combinations of statistics to evolve the virtual character.
[0019] FIG. 4 is an illustrative notional data structure showing statistics of a virtual character and possible combinations of statistics to evolve the virtual character.
[0020] FIG. 5 is an illustrative notional data structure showing statistics of a virtual character and possible combinations of statistics to evolve the virtual character.
[0021] FIG. 6 is an illustrative notional data structure showing statistics of a virtual character and possible combinations of statistics to evolve the virtual character.
[0022] FIG. 7 is a conceptual diagram illustrating evolution of default strings into multiple combinations and sub-combinations over time.
[0023] FIGS. 8A-8B are conceptual diagrams illustrating an interaction between two virtual characters before and after a change of the second character's script.
DETAILED DESCRIPTION
[0024] Methods and arrangements of evolving virtual characters for gaming applications and virtual worlds are disclosed in this application.
[0025] Before embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of the examples set forth in the following descriptions or illustrated drawings. The invention is capable of other embodiments and of being practiced or carried out for a variety of applications and in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting.
[0026] Before embodiments of the software modules or flow charts are described in detail, it should be noted that the invention is not limited to any particular software language described or implied in the figures and that a variety of alternative software languages may be used for implementation of the invention.
[0027] It should also be understood that many components and items are illustrated and described as if they were hardware elements, as is common practice within the art. However, one of ordinary skill in the art, and based on a reading of this detailed description, would understand that, in at least one embodiment, the components comprised in the method and tool are actually implemented in software.
[0028] As will be appreciated by one skilled in the art, the present invention may be embodied as a system, method or computer program product. Accordingly, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment (including firmware, resident software, micro-code, etc.) or an embodiment combining software and hardware aspects that may all generally be referred to herein as a “circuit,” “module” or “system.” Furthermore, the present invention may take the form of a computer program product embodied in any tangible medium of expression having computer usable program code embodied in the medium.
[0029] Computer program code for carrying out operations of the present invention may be written in any combination of one or more programming languages, including an object oriented programming language such as Java, Smalltalk, C++ or the like and conventional procedural programming languages, such as the “C” programming language or similar programming languages. The program code may execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer or server. In the latter scenario, the remote computer may be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection may be made to an external computer (for example, through the Internet using an Internet Service Provider).
[0030] A “virtual world” as used herein need not be a “game” in the traditional sense of a competition in which a winner and/or loser is determined, but rather that the term “game” incorporates the idea of a virtual world. Moreover, a person or entity that enters the virtual world in order to conduct business, tour the virtual world, or simply interact with others or the virtual environment, with or without competing against another person or entity is still considered to be “playing a game” or engaging in the gameplay of the game.
[0031] Virtual worlds can exist on game consoles for example Microsoft Xbox, and Sony Playstation, Nintendo Wii, etc., or on online servers, or on mobile devices (e.g. an iPhone or an iPad), Smartphones, portable game consoles like the Nintendo 3DS, or on a PC (personal computer) running MS Windows, or MacOS, Linux or another operating system. This list is not exhaustive but is exemplary of devices or computing environments where virtual worlds can exist, many other variations are available and known to persons skilled in the art.
[0032] A computer or a game console that enables a user to engage with a virtual world, including a memory for storing a control program and data, and a processor (CPU) for executing the control program and for managing the data, which includes user data resident in the memory including a set of gameplay statistics. The computer, or a game console, may be coupled to a video display such as a television, monitor, or other type of visual display while other devices may have it incorporated in them (iPad). A game or other simulations may be stored on a storage media such as a DVD, a CD, flash memory, USB memory or other type of memory media. The storage media can be inserted to the console where it is read. The console can then read program instructions stored on the storage media and present a game interface to the user.
[0033] Typically, a user or a player manipulates a game controller to generate commands to control and interact with the virtual world. The game controller may include conventional controls, for example, control input devices such as joysticks, buttons and the like. Using the controller a user can interact with the game, such as by using buttons, joysticks, and movements of the controller and the like. This interaction or command may be detected and captured in the game console. The user's inputs can be saved, along with the game data to record the game play. In one embodiment, the gameplay data can include usage statistics captured to record the user's experience as they progress from one level of the game to the next.
[0034] The term “player” is intended to describe any entity that accesses the virtual world, regardless of whether or not the player intends to or is capable of competing against other players. Typically, a player will register an account with the game console within a peer-to-peer game and may choose from a list or create virtual characters that can interact with other virtual characters of the virtual world.
[0035] The term “engage in gameplay” generally implies playing a game whether it is for the purpose of competing, beating, or engaging with other players. It also means to enter a virtual world in order to conduct business, tour a virtual world, or simply interact with others or a virtual environment, with or without competing against another entity.
[0036] A “virtual character” may include a persona created by a player or chosen from a list in the virtual world. Typically virtual characters are modeled after the humans whether living or fantasy (e.g. characters from mythology). In this disclosure the term virtual character is used interchangeably with villain, boss, monster etc. but the intent is to mean any kind of a virtual character whether it is a protagonist or an antagonist, celebrity, champion, conqueror, charlatan, daredevil, entrepreneur, explorer, fortune-hunter, gambler, globetrotter, hero, heroine, hobbit, madcap, mercenary, magician, mage, opportunist, pioneer, pirate, romantic, speculator, stunt person, swashbuckler, traveler, voyager, wanderer or the like.
[0037] A virtual character is represented by one or more gameplay statistics, which encapsulate some meaning to connect the virtual (and digital) reality of the game to the real world. Many of these statistics are not apparent to the user as such, but are instead encoded within the framework of the game or composed together to form a script. In role-playing games (RPGs) and similar games, these statistics may be explicitly exposed to the user through a special interface, often with added meaning which provides context for the user's actions.
[0038] In virtual worlds (video/computer games) a non-player character (NPC) is a virtual character that is controlled by the program and not a player. NPC may also refer to other entities not under the direct control of players. NPC behavior in a virtual world may be scripted and automatic.
[0039] A “player character” or “playable character” (PC) is a virtual character in a virtual world that is controlled or controllable by a player. A player character is a persona of the player who controls it. In some cases a virtual world has only one player character and in other cases there may be a small number of player characters from which a player may pick a certain virtual character that may suit his or her style of gameplay, while in other scenarios there may be a large number of customizable player characters available from which a player may choose a virtual character of their liking. An avatar—may include the physical embodiment of a virtual character in the virtual world.
[0040] The system and method described in the patent disclosure is equally applicable to any type of a virtual character whether it is protagonist or an antagonist, PC or NPC, male or female, or any other kind that is obvious to the one skilled in the art.
[0041] Statistics (Stat)
[0042] A “statistic” (stat) in role-playing games (RPG) is a datum which represents a particular aspect of a virtual character. Most virtual worlds separate statistics into several categories. The set of categories actually used in a game system, as well as the precise statistics within each category may vary greatly from one virtual world to another. Many virtual worlds also use derived statistics whose values depend on other statistics, which are known as primary or basic statistics. Derived statistics often represent a single capability of the character such as the weight a character can lift, or the speed at which they can move. Derived statistics are often used during combat, can be unitless numbers, or may use real-world units of measurement such as kilograms or meters per second.
[0043] Primary Statistics represent assigned, abstract qualities of a virtual character, such as Strength, Intelligence, and so on. Partially defined by convention and partially defined by context, the value of a primary statistic corresponds to a few direct in-game advantages or disadvantages, although a higher statistic is usually better. In this sense, primary statistics can only really be used for direct comparison or when determining indirect advantages and disadvantages.
[0044] Derived Statistics represent measured, concrete qualities of a virtual character, such as maximum carry weight, perceptiveness, or skill with a weapon. Such a stat is derived from some function of one or more of a character's primary stats, usually addition or multiplication. These stats then serve an important function in turn, providing a fair means by which to arbitrate conflicts between virtual characters and the virtual environment. For example, when two virtual characters are in violent conflict, Strength, a primary statistic, might be used to calculate damage, a derived statistic, with the winner being the character with the most damage.
[0045] Other factors may affect derived statistics, such as other derived or primary statistics, or even environmental factors, such as weather conditions. In these cases, the environment can be modeled as a virtual character with its own primary statistics or it may be given a special role in conflict resolution. Whatever-the-case, the role of primary statistics should remain clear because this is the primary interface by which players understand their interactions within the virtual world.
[0046] Some statistics deserve special mention. “Health (or Hit Points) vs. Damage,” describes a gameplay mechanic that has fixated the current generation of games. Damage refers to a primary or (usually) derived statistic that represents a character's ability to destroy or cause harm to the environment or virtual characters. Likewise, Health (or Hit Points) refers to a primary or (usually) derived statistic that represents a character's ability to withstand damage and continue to function normally. Each time a character suffers damage, that amount of damage is subtracted from their remaining health or hit point total, and if this total is now zero or less, the character is eliminated or the player loses.
[0047] A virtual character's statistics affects how it behaves in a virtual world. For example, a well-built muscular virtual character may be more powerful and be able to throw certain virtual objects farther, but at the same time may lack dexterity when maneuvering intricate virtual objects. A virtual character may have any combination of statistics, but these statistics may be limited by either a hard counter, soft counter or a combination of both. The most often used types of statistic include but are not limited to the following:
[0048] Attribute/Ability
An “attribute/ability” describes to what extent a virtual character possesses a natural, in-born characteristic common to all virtual characters in the game. Ability defines a quality in a virtual character to perform certain actions, for example wield a sword or to run. Many games use attributes to describe a virtual characters' physical and mental characteristics, for example their strength or wisdom. Many games also include social characteristics as well, for example a character's natural charisma or physical appearance which often influence the chance to succeed in a particular challenge. Some games work with only a few broad attributes, while others may have several more specific ones.
[0050] Trait
“Traits” may be stable personal characteristics (i.e., temperament or physical endowment) that are additional qualities that help define a virtual character. Traits can be positive or negative. Traits also affect the ability to build particular skills. For instance, an active virtual character will find it easier to develop a more muscular body than an inactive one. Generally a trait represents a broad area of expertise of a character.
[0052] Skills
A “skill” represents the learned knowledge of a virtual character. Skills are manifestations of abilities and traits. During the creation of a virtual character, skills are generally chosen from a list. A virtual character may have a fixed number of starting skills, or a player can acquire them by spending game points. Each skill has an associated attribute and can be improved upon by practicing. For example if a virtual character has the ability to wield a sword and has the trait of being physically strong then the skill of being a swordsman can be accomplished by practicing wielding the sword. As opposed to abilities few games set a player's skills at the start of the game, instead allowing players to increase them by playing the game and spending game points or during moving from a low level to a higher level in the game. Some skills are likely to be more useful than others therefore different skills often have different costs in terms of game points.
[0054] Advantages and Disadvantages
An “advantage” is a physical, social, intellectual, or other enhancement to a virtual character, while a disadvantage is an adverse effect. Advantages are also known as virtues, merits or edges and disadvantages as flaws or hindrances. Many games encourage or even force players to take disadvantages for their characters in order to balance their advantages or other positive statistics.
[0056] Powers
“Powers” represent unique or special qualities of a virtual character and often grant the virtual character the potential to gain or develop certain advantages or to learn and use certain skills.
[0058] For the purpose of this application the term “gameplay statistics” refers to any one or any combination of gameplay frequency, gameplay time, number of times game played, percent game complete etc. as result of engaging in gameplay.
[0059] Encounters
[0060] In a virtual world an “encounter” may be defined as a meeting between two or more virtual characters or may be thought of as a decision point at which a player encounters an opposing element (e.g. an enemy). An encounter may be player initiated (actively engaging in fighting an enemy) or unwanted by the player. A player may opt to avoid an encounter or may actively engage in them to move to the next level of the virtual world. The outcome of the encounters may at times define how the rest of the game progresses.
[0061] A random encounter is a feature commonly used in various role-playing games (RPGs) whereby an encounter with a non-player character (NPC), an enemy, a monster, or a dangerous situation occurs sporadically and at random. Random encounters are generally used to simulate the challenges associated with being in a hazardous environment, such as a monster-infested wilderness or dungeon usually with an uncertain frequency of occurrence to simulate a chaotic nature.
[0062] Settings
[0063] “Settings” in the virtual world control multiple areas of the virtual world (game). Settings may be changed by a player or may be impacted by the location of a player.
[0064] Levels
[0065] A “level” in the virtual world (video game) terminology refers to a discrete subdivision of the virtual world. Typically a players begins at the lowest level (level 1 ), and proceeds through increasingly numbered levels, usually of increasing difficulty, until they reach the top level to finish the game. In some games levels may refer to specific areas of a larger virtual world, while in other games it may refer to interconnected levels, representing different locations within the virtual world.
[0066] FIG. 1 is a flow diagram illustrating the primary steps of the method, according to a preferred embodiment. A system is provided with a virtual world 101 . The virtual world may be a single player game or a multiplayer game or a MMORPG (Massively Multiplayer Online Role Playing Game) and may exist on any type of a gaming device which may include but not limited to an iPhone, iPad, Smartphones, Android phones, personal computers e.g. laptops, gaming consoles like Nintendo Wii, Nintendo DS, Sony PlayStation, Microsoft Xbox 360, and online server based games etc.
[0067] The computer program comprises: a computer usable medium having computer usable program code, the computer usable program code comprises: computer usable program code for enabling change in storyline based on the real world location of a player, computer usable program code for presenting graphically to the player the different options available to modify and personalize different aspects of the virtual world including but not limited to settings.
[0068] The player engages in gameplay of the virtual world 102 . As mentioned earlier, the term “engage in gameplay” generally implies playing a game whether it is for the purpose of competing, beating, or engaging with other players. It also means to enter a virtual world in order to conduct business, tour a virtual world, or simply interact with others or a virtual environment, with or without competing against another entity.
[0069] When the player game style or moves become repetitive during an encounter with a villain while also inflicting a certain amount of damage to the villain virtual character, the system changes the behavior of the villain virtual character 103 .
[0070] The behavior of said villain virtual character may be altered by changing the default script that is controlling the behavior of the virtual character. A script defines the default behavior of a virtual character. If there is no external stimulus a virtual character acts as per the default script. Just as with statistics, different scripts can refer to different behaviors for virtual characters.
[0071] The changed behavior of the villain virtual character renders the player's moves ineffective in inflicting damage to the villain virtual character 104 .
[0072] In one embodiment of the invention, another string that is already present in the string set can be used to alter the behavior of the villain virtual character, forcing the player to seek other moves in continuing to defeat the said villain character. Once all strings in the string set have been used to alter the behavior of the villain virtual character, stats can be combined from different strings in the string set associated with the virtual character to form a new string to change the behavior of said villain virtual character.
[0073] In another embodiment, new strings can be obtained by combining stats from more than one script (or strings) associated with the said villain virtual character.
[0074] In another embodiment, any virtual character may follow this path of changing behavior, and it is not just limited to the villain, boss, or monster.
[0075] In one embodiment, when a first player engages in gameplay with the virtual character of a virtual world, this interaction may alter the existing default scripts by combining elements from more than one string that may be already present in the virtual world.
[0076] Even with a default script of a single virtual character, many behaviors are possible. In fact, the manner by which derived statistics are calculated can itself be defined by a particular script, rather than a simple function. For this reason, it is sometimes difficult to determine whether a derived statistic refers more to a particular measurable quality or the behavior that defines that quality. For example, a skill may be represented by a statistic where a higher value corresponds to a higher degree of skill in some particular endeavor. However, a trait may refer to the behavior that defines that trait, rather than simply a statistic. In this way, it is important to distinguish when skills, traits, abilities, and other game components are represented by statistics or behaviors.
[0077] Once altered, the new string (which is a combination of two or more earlier strings) can be saved in the preferred memory location. Most devices where virtual worlds exist provide a mechanism to save the state of the game, so that the game can be played from the same point where it was left off. Methods for saving the state of the game include but are not limited to the examples cited here, for example a gaming console may provide internal memory chips, or a port where a user can connect user supplied memory; while games played over the Internet may provide online memory. The aforementioned memory space can also be used for saving the different components of the storyline that are affected by the change in the real world location of the player to enhance the gameplay experience.
[0078] The memory location may be the local data storage (internal memory) of a game console including one for the linked linkable and extensible virtual character. The local data storage can be local inbuilt memory (for example on board memory) or user provided (for example a USB device, a Flash Memory SD card etc.) such that said memory is accessible to other virtual worlds. In another embodiment the memory location may be an online server
[0079] FIG. 2 is a flow diagram illustrating an ongoing process for evaluating repetitive and damaging moves to trigger evolving a virtual character by changing strings. Gameplay starts using a default script for the virtual character and monitor player moves/keystrokes 201 . The player may use any one of the several possible mechanisms to interact with the virtual world including but not limited to a gamepad, keyboard, mouse, joystick, wired game controller, wireless remote game controller or other such mechanism. To monitor player moves and keystrokes implies taking into consideration the moves that a player is making and checking for a pattern.
[0080] The system checks to see if the player's moves/keystrokes are repetitive 202 . If No 202 a (i.e. the player's moves/keystrokes are not repetitive) then gameplay of the virtual world continues 207 and the system continues to monitor player moves/keystrokes periodically 201 . Any key combinations or button combinations that are used more frequently than other combinations, or being used repetitively for example pressing the “fire” button repeatedly to fire indiscriminately would fall in this category.
[0081] If there are no repeated patterns in the player moves in a given time period then it can be concluded that the player moves are non-repetitive.
[0082] If Yes 202 b (i.e. there are repeated patterns in the moves that a player is making in a given period of time), then it can be concluded that the player moves are repetitive. For example pressing the “fire” button repeatedly with no other significant moves made over a given period of time e.g. 60 seconds concludes that the player is using a repeated move.
[0083] The system (concurrently or in sequence) checks how much damage is being inflicted on a villain virtual character due to the repetitive moves of a player 203 .
[0084] Health is a game mechanic used in virtual worlds to give a value to virtual characters, enemies, NPCs, (non player characters) and related virtual objects. Health is often abbreviated by HP which may stand for health points or hit points; it is also synonymous with damage points or heart points. In virtual worlds health is a finite value that can either be numerical, semi-numerical as in hit/health points, or arbitrary as in a life bar, and is used to determine how much damage (usually in terms of physical injury) a virtual character can withstand when said virtual character is attacked, or sustains a fall. The total damage dealt (which is also represented by a point value) is subtracted from the virtual character's current HP. Once the virtual character's HP reaches 0 (zero), the virtual character is usually unable to continue to fight or carry forward the virtual world's mission.
[0085] A typical life bar is a horizontal rectangle which may begin full of color. As the virtual character is attacked and sustains damage or mistakes are made, health is reduced and the colored area gradually reduces or changes color, typically from green to red. At the start of a typical game, the virtual character may have 100% health. At some point the life bar changes color completely, or loses color; at this point the virtual character is usually considered dead.
[0086] To assess damage, the system checks whether the inflicted damage to the health of the villain virtual character is greater than a threshold 204 . For example, the threshold may be 8% and if repeated moves by a player are causing a 10% damage to the health of a villain virtual character then it can be safely assumed that if the player continues to repeat these moves then in 10 such moves the health of the said virtual character will reach zero and the player would have effectively defeated the villain.
[0087] If No 204 a (i.e. the inflicted damage to the health of the villain virtual character is less than the defined threshold) then gameplay continues 207 and the system periodically monitors the player activity and the inflicted damage.
[0088] If Yes 204 b (i.e. the inflicted damage to the health of the villain virtual character is greater than the defined threshold) then the system combines stats from different strings associated with the villain virtual character 205 . The villain virtual character is evolved to incorporate the new strings 206 and gameplay continues 207 and the system periodically monitors the player activity and the inflicted damage on the villain virtual character.
[0089] The system learns when a player uses repeated moves and the moves inflict more than a given range/percentage damage to the virtual character's health points. When such a situation arises the system is able to take more than one strings associated with the villain virtual character that the player is combating with, and combine the stats from these strings to create a new string, or replace one entire string with another, to change the behavior of the villain virtual character. Thus after this change of stats by either replacing a string with another or combining stats from several strings, the moves that the player was using to inflict damage on the villain virtual character will no longer be effective and the player will have to discover another move or combination of moves to be able to defeat the villain virtual character.
[0090] Thus we note that the villain virtual character can be evolved by either changing the default script with another one that may be part of the string set for that virtual player, or by creating a new string by combining the stats of two or more strings that may be present in the string set for said virtual character. In alternate embodiments the strings may also be downloaded from a server, purchased, sold, exchanged, gifted, won, lost, etc. The invention is not limited to these examples, but the intent is to cover all such possibilities that are obvious to persons skilled in the art.
[0091] The occurrence and outcome of special bonus features, the amounts wagered on any bets, the outcomes for any intermediate game stages, the results of any player decisions made during the game, bonus plays and their outcomes, the final game outcomes etc. may also change as a result of combining the stats from different strings.
[0092] In one embodiment of the invention, a method of combining the stats of different strings associated with a virtual character may use a certain data structure to define the statistics of the virtual characters in each of the virtual worlds. One such method to save the statistics is to use an XML structure.
[0093] In one embodiment of the invention, the presence or absence of a Skill, Ability, Trait, Advantage, Disadvantage or Power is represented by a “1” or a “0” respectively. One exemplary data structure that may be used to define a virtual character's statistics is shown in FIG. 3 .
[0094] The data fields may be arranged in a given order, so that the statistics from one string associated with a virtual character in a virtual world correspond to the same statistics in another string for the same virtual character in the same virtual world. In another embodiment there may be a mapping mechanism that may translate the statistics of one string associated with a virtual character to that of another string associated with the same virtual character. The data structure may be a file e.g. an XML file, or a table, or a database, or a string.
[0095] The data structure fields may be ordered to allow different strings associated with a virtual character to correspond uniformly to one another. For example, “Strength” may be the first field in this ordering, “Wisdom” may be the second field and so on. Therefore when one or more strings associated with a virtual character are combined, statistics for the relevant data fields are composed by some function, for example in one case Strength is added to Strength, while Wisdom from one string is subtracted from the value of Wisdom in another string.
[0096] In another embodiment of the invention, there may be mapping that allows the data structure fields to be mapped indirectly from one to the other so that the relevant data fields correspond with each other. This is especially relevant for derived statistics. For example, if the “Dodge Skill” in one string is composed of the “Dexterity” primary statistic and a “Dodge Training” secondary statistic, and the “Reflex Save” derived statistic in another string is composed of “Dexterity” and “Perception” primary statistics, then the “Dodge Skill” and “Reflex Save” can be composed when combining the stats from these strings.
[0097] In another embodiment, where there may be a non-uniform number of data fields (if, for example, one set of statistics has 5 data fields and the other set of statistics has 8 data fields) the mapping allows for the relevant data fields to correspond. Thus the combined string may take all or some of the stats when creating a new string to change the behavior of the virtual character.
[0098] For each of the statistics that are present in a virtual character, there may be a corresponding value that defines the extent of that particular statistic. For some statistics the possible range of values may include positive numbers, zero and negative numbers. Thus when the value is a positive number there may be a beneficial effect (positive effect), while a zero implies no effect and a negative number implies a negative effect. One such exemplary data structure showing a string of statistics associated with a given virtual character is shown in FIG. 5 . The top row shows the presence or absence of a particular statistic while the second row shows a value that defines the quality of that particular statistic if it is present.
[0099] Another exemplary data structure showing the statistics of a second string associated with the same virtual character is shown in FIG. 5 . The top row shows the presence or absence of a particular statistic while the second row shows a value that defines the quality of that particular statistic if it is present.
[0100] In one embodiment when a first string associated with a given virtual character in a virtual world is combined with a second string also associated with the same virtual character, the resultant statistics may be an addition (super-set) of the two previous individual statistics of the first and second strings associated with the said virtual character. FIG. 6 shows the resultant statistics when statistics of a first string associated with a virtual character in a virtual world ( FIG. 4 ) are combined with the stats of a second string also associated with the same virtual character ( FIG. 5 ). This in FIG. 6 , we see that in the top row statistics are a super-set of the individual statistics of the FIG. 4 and FIG. 5 .
[0101] Similarly the values of the individual statistics that were present in both strings associated with the virtual character may get added (as in this example). Thus values of certain statistics would get reinforced (if both individual values of a certain statistic were either positive or negative) while values of certain other statistics may get negatively impacted (if one value was positive and the other value was negative) due to the combining of the strings associated with said virtual character.
[0102] There may be many different methods of combining the statistics for example in one embodiment while some statistics are added, others are deleted or subtracted as a result of combining two or more strings associated with the same virtual character. The resultant stats are saved as a new string which later may be used for combining with previously existing strings. Thus over time, more and more strings are available for changing the behavior of a virtual character to create variations in the encounters with players.
[0103] In one embodiment there may be more than one default scripts associated with a certain virtual character and are already embedded in a virtual world (game), but are dormant and may get invoked once a player or players discover how to defeat the villain easily. In one embodiment there may be generic scripts associated with virtual characters for example Easy, Medium, Hard etc. As an example stats from the Easy string may be combined with the stats of the Hard string once the players start to defeat the villain easily using repetitive moves. This results in a new string that may be saved to the game and at a later point when stats from more than one string need to be combined, this string may also be used in addition to the default strings that were already embedded in the virtual world. FIG. 7 illustrates this in more detail.
[0104] FIG. 7 shows the changes to a string set for a virtual character over a period of time 700 . At the start of the game, there may be some default strings associated with a virtual character. This is depicted by time t 0 , where the string set 701 may consist of three strings Easy (E), Medium (M) and Hard (H).
[0105] As time passes and player(s) have interacted with the virtual character and all strings in string set 701 have been used to alter the behavior of the virtual character, combine stats from more than one strings to form a new string C 1 (any possible combination of E, M and H strings). This forms the new string set 702 at Time t 1 which now consists of string E, M, H and C 1 .
[0106] Similarly, at Time t 2 , the string set 703 now contains string E, M, H, C 1 and C 2 . As more time passes and player have already engaged in the gameplay involving all the strings in string set 703 , a new string C 3 is added, thus at Time t 3 , the string set 704 now contains string E, M, H, C 1 , C 2 and C 3 . This continues and at Time tn, there are many more strings in the string set 705 including E, M, H, C 1 , C 2 , C 3 up to Cn.
[0107] Turning to FIGS. 8A and 8B , an example is shown of an interaction where the change in string or script has an effect on the outcome. A default script (Script “1”) is invoked in the interaction between First Character 801 A and Second Character 802 A in FIG. 8A . Under these circumstances, the jump attack planned by First Character 801 A would ordinarily result in First Character 801 A defeating Second Character 802 A. First Character 801 A has greater strength and speed than Second Character 802 A.
[0108] However, the tables are turned in FIG. 8B . Due to script change (arising from prior recognition of a pattern of repetitive and damaging moves by the first character against the second character), the script for Second Character 802 B has been changed. Here, the Second Character's 802 B strength and aim stat sub-components have been reshuffled with those of another script (not shown) and are increased. So now, as shown, Second Character 802 B is able to defeat First Character 801 B by virtue of Second Character's 802 B improved aim under Script “Mod 1”.
[0109] The application is not limited to the cited examples, but the intent is to cover all such areas that may be used in a virtual world to impact the evolution of virtual characters in a virtual world.
[0110] In one embodiment of the invention the combined statistics are derived by taking an average of the individual statistics of the different strings associated with the said virtual character. The number of strings used to come up with a new combined sting may vary from one application to another. Thus at least two stings may be required to come up with a new combination. There can be many variations when using multiple strings e.g. using 3 stings, using 4 stings, using 5 stings with average of all stat elements, using 4 strings with weighted averages etc.
[0111] In another embodiment of the invention the combined statistics are derived by taking a weighted average of the individual statistics of two or more strings associated with said virtual character, with preference (weight) given to any one of the stats where the preference can be either user defined, based on the player's gaming style or system driven.
[0112] A player's gaming style can be defined by player preferences, which may have been captured by either tracking the player's gaming style or by asking the player a series of questions, and then the answers from these questions determining the gaming style which in turn impacts the evolution of the virtual characters. That is how stings are combined, or which elements in the stings are combined may vary with the gaming style of the player.
[0113] A script defines the default behavior of a virtual character. Just as with statistics, different scripts can refer to different behaviors. Using the method and system of the invention, a default script of a virtual character may define its default behavior and in order to implement an altered behavior associated with a change in location a certain other script may be used instead of the default script of a virtual character.
[0114] The system of the invention may import scripts associated with virtual characters, so that the resulting combination is more varied and thus more sophisticated.
[0115] In another embodiment the scripts associated with different virtual characters may be downloaded (either automatically or by player request) from a central server that acts as a repository for additional scripts. In another embodiment the user may have to pay when acquiring these additional scripts e.g. from a remote server.
[0116] In another embodiment the combined statistics are derived by taking an average of the individual statistics of the different strings associated with a virtual character.
[0117] In yet another embodiment the combined statistics are derived by taking a weighted average of the individual statistics of the different strings associated with the virtual characters, with preference (weight) given to any one of the stats and where the preference can be either user defined or system driven.
[0118] It should be understood that although the terms “script” and “string” have been used interchangeably to imply the mechanism for altering the behavior of the virtual character, the intent is to cover all such mechanism that can provide this functionality.
[0119] One embodiment of the invention may preferably also provide a framework or an API (Application Programming Interface) for virtual world creation that allows a developer to incorporate the functionality of evolving virtual characters as more players interact with them. Using such a framework or API allows for a more exciting virtual world generation, and eventually allows for more complex and extensive ability to keep a player engaged over a longer duration of gameplay.
[0120] It should be understood that although the term game has been used as an example in this application but in essence the term may also imply any other piece of software code where the embodiments of the invention are incorporated. The software application can be implemented in a standalone configuration or in combination with other software programs and is not limited to any particular operating system or programming paradigm described here. For the sake of simplicity, we singled out game applications for our examples. Similarly we described users of these applications as players. There is no intent to limit the disclosure to game applications or player applications. The terms players and users are considered synonymous and imply the same meaning. Likewise, virtual worlds, games and applications imply the same meaning. Thus, this application intends to cover all applications and user interactions described above and ones obvious to persons skilled in the art.
[0121] Although virtual world have been exemplified above with reference to gaming, it should be noted that virtual worlds are also associated with many industries and applications. For example, virtual worlds can be used in movies, cartoons, computer simulations, and video simulations, among others. All of these industries and applications would benefit invention.
[0122] The examples noted here are for illustrative purposes only and may be extended to other implementation embodiments. While several embodiments are described, there is no intent to limit the disclosure to the embodiment(s) disclosed herein. On the contrary, the intent is to cover all alternatives, modifications, and equivalents obvious to those familiar with the art.
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A computer-implemented method is provided for providing virtual gameplay. Access is provided to a video game in which players are able to interact via characters and each character behaves according to a series of scripts in a script set. A first player character is monitored as it interacts with a second character in the video game. The second character responds according to a script in its script set. When the first player character exhibits repetitive behaviour in the interaction that causes damage to the second character that exceeds a preset damage threshold, the second character's script is changed and the changed script is stored for future use. As strings are changed over successive iterations, the second character evolves.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates to a magnetic head slider and head gimbal assembly, and to a manufacturing method and manufacturing apparatus therefor, and more particularly to manufacturing technology for reducing the variation in flying height among the individual magnetic head sliders and head gimbal assemblies manufactured.
[0003] 2. Description of the Related Art
[0004] In a magnetic disk drive, a magnetic head slider is used that flies while maintaining a minute interval between itself and a disk recording medium that rotates. Ordinarily, the slider will comprise, at the leading edge thereof, a magnetic transducer for recording information on and playing back information from the disk recording medium, and is subject to demands to make the bit density higher and the track width narrower in order to realize higher recording density. It is particularly demanded that the slider be made to fly in a condition of low flying height wherein it is made to approach as close as possible to the disk recording medium, in order to raise the bit density. In order to implement data recording and playback with sufficient reliability in such a low-flying-height condition, a critically important task is that of lowering the flying height differences, that is, the variation in the flying height, between individual manufactured sliders.
[0005] The negative pressure slider is effective in reducing flying height variation, and is widely and generally used. With the negative pressure slider, because of the high rigidity of the air film that develops between the disk recording medium and the flotation surface, it is possible to reduce flying height variation and fluctuation that arise from the static attitude and load wherewith the suspension supporting the slider presses against the disk recording medium, suspension vibration, and disk waviness in the disk recording medium, etc., and thus the negative pressure slider is effective in effecting lower flying height.
[0006] Nevertheless, the demands for lower flying height are becoming increasingly severe year by year, with efforts being made to achieve a flying height of 10 nm in the face of demands to lower the flying height as much as possible in a condition wherein no contact with the disk recording medium occurs. It is in this area of such low flying height that variation in the flying height among individual manufactured sliders becomes particularly problematic. If there is a variation of 5 nm in the flying height in sliders designed for a flying height of 10 nm, for example, changes of only 5 nm will be allowed in the flying height variation associated with the surface roughness of the slider and disk recording medium, the surface waviness of disk recording medium, and environmental variation (in pressure, temperature, etc.). Accordingly, in order to achieve lower flying height, in addition to reducing flying height variation induced by environmental changes or undulations and surface roughness that are physical flying height loss [factors], the variation in flying height among individual manufactured sliders must also be reduced.
[0007] Manufacturing methods and manufacturing apparatuses for reducing such flying height variation among individual manufactured sliders are disclosed, for example, in Japanese Patent Application Laid-Open No. H6-84312/1994 (published), U.S. Pat. No. 6,073,337, and Japanese Patent Application Laid-Open No. H11-328643/1999 (published). These are manufacturing methods and manufacturing apparatuses that adjust the curvature of the air bearing surface by subjecting the back surface of the slider to laser machining, the basic ideas whereof are as follows.
[0008] First, notice is taken of the fact that one of the manufacturing variation factors that has the greatest effect on flying height variation is the curvature of the air bearing surface. The curvature of the air bearing surface is expressed by the crown, defined as the amount of unevenness from a hypothetically flat plane (curvature∞) looking in the long direction of the slider, the camber, defined as the amount of unevenness from a hypothetically flat plane looking in the short direction of the slider, and the twist, defined as the difference in elevation looking in the diagonal direction of the slider. The curvature of the air bearing surface affects the air pressure produced between the air bearing surface and the disk recording medium and causes the flying height to vary. It is know that, in particular, the crown [factor] in the curvature of the air bearing surface has the greatest effect on the flying height, followed by camber and then twist.
[0009] Accordingly, with the manufacturing methods and manufacturing apparatuses disclosed in the patents noted earlier, stress in the back surface of the slider that has developed during the lapping process in the row bar condition (prior to cutting the slider chips) is melted with a laser, the stress is released, causing the condition of curvature in the air bearing surface to change, and curvature [factors] of the air bearing surface such as the crown are adjusted. By preprogramming the relationship between the laser machining amount, position, and machining pattern and the like and the curvature of the air bearing surface, moreover, the curvature of the air bearing surface can, with a number of repeated machinings, be made to approach close to the design value. The manufacturing methods and manufacturing apparatuses noted above can dramatically reduce the flying height variation resulting from curvature variation in the air bearing surface, and now constitute effective manufacturing technologies for realizing low flying height (of 10 to 25 nm or so) in sliders.
[0010] At flying heights of 25 nm or less, the step negative pressure slider is used which sharply reduces the variation in flying height relative to changes in temperature and atmospheric pressure. In the step negative pressure slider, as described in detail in Japanese Patent Application Laid-Open No. 2000-57724 (published), step bearings are adopted which have a submicron or smaller depth of large air bearing effect, and a negative pressure channel is designed at a depth where the negative pressure generated in the negative pressure channel becomes maximum. Thereby, a larger negative pressure can be utilized as compared to a conventional negative pressure slider, wherefore the rigidity of the air film becomes even higher, and the flying height variation caused by changes in the static attitude and the load wherewith the suspension presses on the disk recording medium is reduced.
[0011] The particulars relating to this reduction in flying height variation also apply to a head gimbal assembly. What should be given attention here is the technology, disclosed in U.S. Pat. No. 6,011,239, for adjusting the load and static attitude of the suspension, by applying laser processing to the suspension, so that the flying height while the slider is being made to fly coincides with the design value. The manufacturing technology disclosed here is aimed at the realization of sliders that exhibit small flying height variation.
SUMMARY OF THE INVENTION
[0012] However, step bearings of submicron or smaller depth require high machining precision and have a great effect on flying height variation. Also, because the flying height variation is reduced by adjusting the curvature of the air bearing surface as described earlier, the main cause of flying height variation in a step negative pressure slider becomes the variation in the depth of the step bearings. Furthermore, because the step bearings are formed by a machining method such as ion milling, the numerical quantities machined at one time are large, and [flying height variation] appears as a shift in the average value of the flying height in units of [whole] lots. Because the flying height average value shift greatly influences slider flying height yield, difficult cost-related problems sometimes develop.
[0013] Such flying height average value shifts cannot be resolved merely by regulating the machining so that the curvature is kept to that which is determined by certain specifications as conventionally. As flying heights become increasingly lower, the seriousness of flying height variation induced by flying height average value shift will increase. In order to resolve this [problem], the objective must be made that of minimizing flying height variation between individual manufactured sliders, and not merely that of minimizing manufacturing variation such as in air bearing surface curvature and the like.
[0014] An object of the present invention is to provide a manufacturing method wherewith the flying height of a magnetic head slider is predicted from shape data thereof, and flying height variation is reduced by adjusting the curvature of the air bearing surface according to the predicted flying height, together with a manufacturing apparatus using that method, and also a head gimbal assembly and magnetic disk drive wherein a magnetic head slider manufactured with that manufacturing apparatus is mounted.
[0015] In order to attain the object noted above, the magnetic head slider manufacturing method of the present invention comprises the steps of: inputting slider shape data; calculating the predicted slider flying height, taking those shape data into consideration; calculating a target curvature for making adjustments from the difference in that predicted flying height and the desired target flying height; and adjusting the curvature of the air bearing surface to that target curvature.
[0016] Alternatively, [the magnetic head slider manufacturing method of the present invention] comprises the steps of: measuring slider shape data; calculating the predicted slider flying height, taking those shape data into consideration; calculating a target curvature for making adjustments from the difference in that predicted flying height and the desired target flying height; and adjusting the curvature of the air bearing surface to that target curvature.
[0017] By slider shape data are meant at least one type among the step bearing depth, negative pressure channel depth, rail width, and air bearing surface curvature.
[0018] The manufacturing apparatus for manufacturing a magnetic head slider by those manufacturing methods comprises: a slider shape data input unit, an arithmetic processing unit for calculating the predicted flying height of the slider, taking those shape data into consideration, and calculating a target curvature for making adjustments from the difference between that predicted flying height and the desired target flying height; and a control unit for adjusting the curvature of the air bearing surface to that target curvature.
[0019] Also, in order to attain the object stated above, the head gimbal assembly manufacturing method of the present invention comprises the steps of: inputting suspension shape data; calculating the predicted slider flying height taking those shape data into consideration; calculating a target curvature for making adjustments from the difference between that predicted flying height and the desired target flying height; and adjusting the curvature of the air bearing surface to that target curvature.
[0020] Alternatively, [the head gimbal assembly manufacturing method of the present invention] comprises the steps of: measuring suspension shape data; calculating the predicted slider flying height taking those shape data into consideration; calculating a target curvature for making adjustments from the difference between that predicted flying height and the desired target flying height; and adjusting the curvature of the air bearing surface to that target curvature.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] [0021]FIG. 1 is a diagram representing a magnetic head slider manufacturing method and manufacturing apparatus according to a first embodiment aspect;
[0022] [0022]FIG. 2 is a diagonal view of a typical magnetic head slider, wherein the present invention can manifest effects, seen from the air bearing surface;
[0023] [0023]FIG. 3 is an arrow-view diagram of the section at the A-A′ line in FIG. 2;
[0024] [0024]FIG. 4 is a plan of a magnetic disk drive wherein is mounted a magnetic head slider relating to the present invention;
[0025] [0025]FIG. 5 is a flowchart for describing a magnetic head slider manufacturing method and manufacturing apparatus according to the first embodiment aspect of the present invention;
[0026] [0026]FIG. 6 is a diagonal view of a typical magnetic head slider, wherein the present invention can manifest effects, seen from the back surface thereof;
[0027] [0027]FIG. 7 is a graph that plots the relationship between the amount of shift in the depth δs of a step bearing in the slider diagrammed in FIG. 2 from the design value and the amount of flying height change in the vicinity of the leading edge;
[0028] [0028]FIG. 8 is a graph that plots the relationship between the amount of shift in the crown of the slider diagrammed in FIG. 2 from the design value and the amount of flying height change in the vicinity of the leading edge;
[0029] [0029]FIG. 9 is a model diagram for describing changes in the flying height of a magnetic head slider based on a conventional manufacturing method and manufacturing apparatus;
[0030] [0030]FIG. 10 is a model diagram for describing changes in the flying height of a magnetic head slider based on the manufacturing method and manufacturing apparatus of the present invention;
[0031] [0031]FIG. 11 is a diagram representing a magnetic head slider manufacturing method and manufacturing apparatus according to a second embodiment aspect of the present invention;
[0032] [0032]FIG. 12 is a diagram representing a magnetic head slider manufacturing method and manufacturing apparatus according to a third embodiment aspect of the present invention;
[0033] [0033]FIG. 13 is a flowchart for describing a magnetic head slider manufacturing method and manufacturing apparatus according to the third embodiment aspect of the present invention;
[0034] [0034]FIG. 14 is a diagonal view of a typical head gimbal assembly wherein the present invention can manifest effects;
[0035] [0035]FIG. 15 is a graph that plots the relationship between the amount of shift in the load of the head gimbal assembly diagrammed in FIG. 13 from the design value and the amount of flying height change in the vicinity of the leading edge;
[0036] [0036]FIG. 16 is a diagram representing a magnetic head slider manufacturing method and manufacturing apparatus according to a fourth embodiment aspect of the present invention;
[0037] [0037]FIG. 17 is a flowchart for describing the magnetic head slider manufacturing method and manufacturing apparatus according to the fourth embodiment aspect of the present invention;
[0038] [0038]FIG. 18 is a diagram representing a magnetic head slider manufacturing method and manufacturing apparatus according to a fifth embodiment aspect of the present invention;
[0039] [0039]FIG. 19 is a diagram representing a magnetic head slider manufacturing method and manufacturing apparatus according to a sixth embodiment aspect of the present invention; and
[0040] [0040]FIG. 20 is a flowchart for describing the magnetic head slider manufacturing method and manufacturing apparatus according to the sixth embodiment aspect of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0041] [0041]FIG. 1 is a diagram for describing a magnetic head slider manufacturing method and manufacturing apparatus according to a first embodiment aspect of the present invention. Before giving a detailed description of the present invention, the typical magnetic head slider diagrammed in FIG. 2 and the magnetic disk drive diagrammed in FIG. 4, wherein the present invention can manifest effects, are described.
[0042] The slider 1 diagrammed in FIG. 2 is configured so as to comprise an trailing edge 2 , a air bearing surface 3 , and an leading edge 4 . Here the air bearing surface 3 of the slider 1 is configured of a front pad 13 , a negative pressure channel 12 , and a center pad 14 , where in turn the front pad 13 is configured of a front step bearing 5 formed so as to continue from the trailing edge 2 , a pair of side rail surfaces 6 and 7 formed so as to continue from that front step bearing 5 , and a pair of side step bearings 8 and 9 having the same depth as the front step bearing 5 , the negative pressure channel 12 is enclosed by the pair of side rail surfaces 6 and 7 and the pair of side step bearings 8 and 9 , and the center pad 14 comprises a center rail surface 11 on the leading edge 4 side of the slider 1 , and a rear step bearing 10 formed so as to enclose the center rail surface 11 , at the same depth as the front step bearing 5 .
[0043] The front step bearing 5 and the side step bearings 8 and 9 function as an air induction unit that efficiently forms a stiff air film (compressed air layer) between the air bearing surface 3 (bearing surface) and the surface opposite (the recording surface of the disk recording medium 25 ). This stiff air film functions to prevent direct contact between the air bearing surface 3 and the disk recording medium 25 , to [facilitate] the slider 1 following the surface shape (deformations due to the crown and undulations) of the disk recording medium 25 , and to maintain the flying height of the slider 1 constant.
[0044] The slider 1 diagrammed in FIG. 2 has a length of 1.25 mm, width of 1.0 mm, and thickness of 0.3 mm. The distance from the trailing edge 2 of the front step bearing 5 to the pair of [side] rail surfaces 6 and 7 is 0.08 mm. The depth δs of the front step bearing referenced to the pair of side rail surfaces 6 and 7 , and to the center rail surface 11 , is 150 nm. The maximum length of the pair of side rail surfaces 6 and 7 as seen in the long direction of the slider is 0.45 mm, the maximum width as seen in the short direction of the slider is 0.305 mm, and the maximum width is 0.68 times the maximum length. FIG. 3, which is an arrow-view diagram of the section at the A-A′ line in FIG. 2, is given for describing the correlations between the pair of side rail surfaces 6 and 7 and the center rail surface 11 , the front step bearing 5 , the side step bearings 8 and 9 , the rear step bearing 10 , and the negative pressure channel 12 . The depth of the pair of side step bearings 8 and 9 and of the rear step bearing 10 in FIG. 3 is the same as the depth δs=150 nm of the front step bearing 5 as already noted (hereinafter sometimes collectively referred to as the step bearings).
[0045] The depth R of the negative pressure channel 12 referenced to the pair of side rail surfaces 6 and 7 , and to the center rail surface 11 (hereinafter sometimes referred to collectively as the rail surfaces) is 1 μm. The center rail surface 11 of the center pad 14 has a magnetic transducer 19 for recording information to and playing back information from the disk recording medium 25 . And the curvature of the air bearing surface 3 of the slider 1 is expressed by the crown, camber, and twist as defined in the prior art.
[0046] A plan of the magnetic disk drive 28 wherein the slider 1 diagrammed in FIG. 2 is mounted is diagrammed in FIG. 4. The magnetic disk drive 28 has mounted therein a 2.5 type disk recording medium 25 that involves a yaw angle variation from approximately +7° to −15°. The yaw angle here is the angle subtended between the long direction of the slider 1 and the direction wherewith air flows in along the circumference of the disk recording medium 25 to the slider 1 due to a swinging movement produced by a rotating actuator 27 , with the slider 1 positioned in opposition to the disk recording medium 25 . As to the sign of the yaw angle, the direction wherein air flows in from the inner circumferential side of the disk recording medium 25 relative to the long direction of the slider 1 is expressed as positive. The magnetic disk drive 28 is configured of the disk recording medium 25 attached to a spindle 26 that rotates at a speed of 4200 rpm, and the slider 1 that is attached to the tip end of a suspension 20 , through the suspension 20 and a carriage 24 [extending] from the rotating actuator 27 . The slider 1 is pressed down with a force of 2.7 gf on the disk recording medium 25 by the suspension 20 , and flies at a flying height of 22 nm or so from the disk recording medium 25 due to the infusion of an air flow produced by the rotating of the disk recording medium 25 between the slider 1 and the disk recording medium 25 . The slider 1 is positioned precisely at any radial position, from approximately 15 to 29 mm, over the disk recording medium 25 by the rotating actuator 27 , and information is recorded to and played back from the disk recording medium 25 , at any position, by the magnetic transducer 19 mounted to the center pad 14 of the slider 1 .
[0047] From this point forward the magnetic head slider manufacturing method and manufacturing apparatus according to the first embodiment aspect of the present invention are described with reference to the FIG. 1 and to the flowchart in FIG. 5. The first embodiment aspect of the present invention is configured of two large modules, as diagrammed in FIG. 5. One of these is a target curvature calculation module 40 , which is characteristic of the present invention, and the other is a machining module 50 that adjusts the curvature of the air bearing surface 3 to the target curvature set by the target curvature calculation module 40 with a laser to the back surface 30 of the slider 1 .
[0048] First, the target curvature calculation module 40 is configured with a flow that [begins with] a shape data input process 41 for setting the shape data 110 of the slider 1 (such data including, for example, the step bearing depth δs, negative pressure channel depth R, rail width, and air bearing surface curvature, etc.), [passes to] a flying height predicting process 42 for calculating the predicted flying height of the slider 1 , taking the shape data into consideration, and reaches a target curvature determination process 43 for calculating the target curvature from the difference between the predicted flying height calculated in the flying height predicting process 42 and the target flying height. Furthermore, the step bearing depths δs used in the shape data 110 are deemed to be identical depths because, in this embodiment aspect, the front step bearing 5 and the side step bearings 8 and 9 are formed in the same machining process. Accordingly, it is only necessary to input [the depth at] any one location. In cases where the front step bearing 5 and the side step bearings 8 and 9 are produced in different machining processes, all of the step bearing depths may be input.
[0049] Similarly, the input of the curvature of the air bearing surface, as with the step bearing depth δs, may be done for any one of the front part, side parts, or rear part, or for all, and the input of the rail width may be any one of the [widths] of the side rail surfaces 6 and 7 or of the center rail surface 11 or may be all.
[0050] Here, the shape data input process 41 in FIG. 1 is executed by a shape data input unit 111 , while the flying height predicting process 42 and the target curvature determination process 43 are executed by an arithmetic processing unit 112 .
[0051] The machining module 50 , on the other hand, is configured of a machining condition input process 51 for inputting such basic machining conditions as the relationship between the curvature of the air bearing surface 3 and the machining amount derived beforehand, laser intensity, machining frequency, and machining pattern, a curvature measurement process 52 for measuring the curvature of the air bearing surface 3 , an adjusting curvature determination process 53 for comparing the target curvature determined by the target curvature calculation module 40 and the measured curvature measured by the curvature measurement process 52 and determining the adjusting curvature of the air bearing surface 3 , a machining assessment process 54 for judging whether to continue or terminate machining, a machining amount calculation process 55 for determining the machining amount in accordance with the adjusting curvature, a machining process 56 for subjecting the back surface 30 of the slider 1 to laser machining in a machining pattern 31 such as diagrammed in FIG. 6, and a final curvature measurement process 57 for measuring the final curvature of the air bearing surface 3 . When it is determined in the machining assessment process 54 to continue the machining, moreover, the machining amount calculation process 55 and then the machining process 56 are implemented, whereupon the curvature measurement process 52 is returned to again to constitute a closed loop.
[0052] Furthermore, the machining condition input process 51 in FIG. 1 is executed by a machining condition input unit 113 that inputs such initial machining conditions, in the machining conditions 114 , as the number of the row bar 1 a , the length of the row bar 1 a , and the position where machining is implemented, etc. The curvature measurement process 52 and the final curvature measurement process 57 are executed in the adjusting curvature determination process 53 , by a curvature measurement unit 101 controlled by a curvature measurement control unit 105 , while the machining assessment process 54 and machining amount calculation process 55 that control the laser output, machining frequency, and such crown amounts as the feed pitch for the stage on which the row bar 1 a is carried are executed by a central control unit 104 . Then the machining process 56 is executed by a laser generator unit 102 that is controlled by a laser control unit 103 , and the row bar 1 a is machined. Finally, by a machining process not diagrammed, the slider is produced by cutting the row bar 1 a at the positions indicated by the broken lines.
[0053] The example described in the foregoing is one wherein a laser is used as the method of adjusting the curvature of the air bearing surface 3 , but other machining methods such as milling or scribing with a diamond needle, etc., that can alter the stress conditions in the air bearing surface 3 or back surface 30 in order to adjust the curvature of the air bearing surface 3 , may also be used.
[0054] The [peculiar] characteristics of the magnetic head slider manufacturing method according to the first embodiment aspect of the present invention are to be found in the target curvature calculation module 40 for reducing flying height variation. Those characteristics are in having means for inputting shape data other than the curvature of the air bearing surface 3 , and the determination, as the target curvature, of the curvature of the air bearing surface 3 at which an amount of flying height change occurs that cancels the amount of flying height change resulting from a shift from the design value in the shape data noted earlier, taking the shape data into consideration.
[0055] As an example, the flow of target curvature determination is described in a case where the step bearing depth δs has shifted from the design value. First, the amounts of change in the flying height in the vicinity of the leading edge 4 of the center rail surface 11 relative to the amount of shift from the design value for the step bearing depth δs are plotted in FIG. 7. In the amounts of change in the flying height plotted in FIG. 7 are indicated the changes when the slider 1 was positioned at a radial position of 15 mm (inner radius) and of 29 mm (outer radius), respectively, over the disk recording medium 25 in the magnetic disk drive 28 . When the amount of shift from the design value for the step bearing depth δs was −10 nm, the amount of change in the flying height was approximately −1 nm at the inner radius and approximately −2 nm at the outer radius. Such changes in the amount of flying height occur similarly when the curvature of the air bearing surface 3 shifts from the design value. For example, the amount of change in the flying height in the vicinity of the leading edge 4 of the center rail surface 11 relative to the amount of shift from the design value of the crown of the slider 1 will be as plotted in FIG. 8. As will be understood from FIG. 8, when the amount of shift from the design value of the crown is +8 nm, the amount of change in flying height will be +1.7 nm at the inner radius and +2 nm at the outer radius. By using this property of the flying height being increased or decreased by these changes in the shape of the slider 1 , the flying height can be adjusted to the target flying height. That is, by causing the crown to be altered +8 nm from the design value so that a change in flying height of approximately +2 nm will occur and thereby canceling the change in flying height of approximately −2 nm at the outer radius caused by the shift in the step bearing depth δs from the design value, the target flying height is maintained.
[0056] The effectiveness of the present invention is also described in comparison against the prior art. Model diagrams that compare the flying condition of a slider 1 based on a conventional manufacturing method and of the slider 1 based on the manufacturing method of the present invention are respectively given in FIG. 9 and FIG. 10. In the slider 1 based on the conventional manufacturing method diagrammed in FIG. 9, [sliders] having the same curvature in the air bearing surface 3 are manufactured, and the flying attitude does not greatly vary, but the flying height in the vicinity of the element cannot maintain the target flying height due to variation in shape [factors] other than curvature, such as the step bearing depth δs, etc. In the slider 1 based on the method of the present invention, on the other hand, the crown and flying attitude change, respectively, but the flying height in the vicinity of the element can support the target flying height. When this is compared with a crown and flying height distribution diagram, the effectiveness becomes patently clear. With respect to the curvature of the air bearing surface 3 of the slider 1 based on the manufacturing method of the present invention, the crown distribution widens because various different target curvature settings are made, taking shape [factors] other than curvature into consideration, but the flying height distribution narrows due to the effectiveness of trying to maintain the target flying height. With the slider 1 based on the conventional manufacturing method, on the other hand, the crown distribution relative to the design value will become narrow, but the flying height distribution will broaden.
[0057] In the first embodiment aspect of the present invention, for the example described in the foregoing, the measured data 110 for the step bearing depth δs are input in a shape data input unit 111 of the target curvature calculation module 40 , the predicted flying height is calculated according to the amount of shift from the design value for the measured data 110 in an arithmetic processing unit 112 , and, in the same arithmetic processing unit 112 , a crown at which a change in flying height will occur that will cancel the difference between the predicted flying height and the target flying height is determined as the target curvature. Here, the calculation of the predicted flying height may be done using a sensitivity coefficient derived from the relationship between the amount of shift from the design value for the step bearing depth δs and the flying height found by simulation or the like [using] the finite-element method or the like, or it may be calculated directly with simulation [employing] the finite-element method or the like. Following thereupon, the curvature of the air bearing surface 3 is adjusted to the target curvature in each part of the machining module 50 , and flying height variation in the slider 1 is reduced by maintaining the target flying height.
[0058] Based on a second embodiment aspect of the present invention, as diagrammed in FIG. 11, the flow of target curvature determination executed in the arithmetic processing unit 112 can be verified with numerical values or graphs with a data display unit 115 that can display [that flow].
[0059] Up to this point, the first embodiment aspect of the present invention has been described taking the step bearing depth δs as an example of slider 1 shape variation, but there are shape variations that cause the flying height to change other than the step bearing depth δs, such as the negative pressure channel depth R and the rail width, etc. If the variation in the flying height relative to these shape variations is first determined, it is possible then to set the target curvature from the relationship between the flying height and curvature [factors] such as the crown, as shown in FIG. 8.
[0060] A magnetic head slider manufacturing method and manufacturing apparatus according to a third embodiment aspect of the present invention are described with reference to FIG. 12 and the flowchart in FIG. 13. In this third embodiment aspect, there is no shape data input unit 111 for inputting shape data 110 for the slider 1 as in the first embodiment aspect, and the target curvature calculation module 40 is configured by only the flying height predicting process 42 and the target curvature determination process 43 . What is characteristic of the third embodiment aspect is that there is a shape measurement process 52 a for measuring such shape data as the step bearing depth δs that is a feature of the curvature measurement unit 101 . A channel depth measurement control unit 106 controls such [factors] as the magnification and focal point of a lens so as to match the air bearing surface, step surface, and negative pressure channel surface in order to measure the channel depth (i.e. the relative distance between the surfaces), and measures shape data using the curvature measurement unit 101 . Then, by passing those shape data to the target curvature calculation module 40 , shape data input is made unnecessary. Processes other than this shape measurement process are the same as in the first embodiment aspect. With this third embodiment aspect, by making the configuration in this manner, the need for other shape measurement equipment is eliminated, the curvature of the air bearing surface 3 can be effected, taking shape variation in the slider 1 into consideration, with the curvature adjustment apparatus only, and a slider 1 of small flying height variation can be manufactured.
[0061] Next, an embodiment aspect of the present invention that reduces flying height variation in a head gimbal assembly condition is described. A typical head gimbal assembly 32 is diagrammed in FIG. 14. The head gimbal assembly 32 is structured such that a mount 33 for attaching it to the carriage 24 of the magnetic disk drive 28 , a suspension 20 for generating a load for pressing the slider 1 against the disk recording medium 25 (which load is expressed hereinafter simply as the load), and a gimbal 34 for flexibly supporting the slider 1 at the tip end of the suspension 20 are attached thereto, with the back surface 30 of the slider 1 adhesively supported by the gimbal 34 .
[0062] The dominant causes of flying height variation in the head gimbal assembly 32 are the load and static attitude of the suspension 20 . The amounts of change in the flying height relative to amounts of shift in the pressing load of the suspension 20 from the design value are as plotted in FIG. 15. In FIG. 15, when the amount of shift in the load from the design value is 4 mN, the amount of change in the flying height is approximately—1.7 nm at the inner radius and approximately 2 nm at the outer radius. Accordingly, if the crown is shifted approximately +8 nm from the design target value in order to cancel the amount of change in the flying height produced by the shift in the load from the design value by the crown of the slider 1 , the target flying height can be maintained, and flying height variation can be reduced.
[0063] A head gimbal assembly manufacturing method and manufacturing apparatus according to a fourth embodiment aspect of the present invention are described with reference to FIG. 16 and the flowchart given in FIG. 17. This fourth embodiment aspect is configured by a target curvature calculation module 40 and a machining module 50 as is the first embodiment aspect. What is characteristic of the fourth embodiment aspect is that the target curvature calculation module 40 is configured by a flow that [begins with] a load and attitude angle data input process 41 a for inputting load or static attitude data 110 a for the head gimbal assembly 32 , [passes to] a flying height prediction process 42 for calculating the predicted flying height, taking the load or static attitude data 110 a into consideration, and reaches the target curvature determination process 43 for calculating the target curvature from the difference between the target flying height and the predicted flying height calculated in the flying height predicting process 42 . Here, the load and attitude angle data input process 41 a in FIG. 16 is executed by the load or static attitude data input unit 111 , and the flying height predicting process 42 and target curvature determination process 43 are executed by the arithmetic processing unit 112 . The machining module 50 , on the other hand, except for the machining being carried on in the head gimbal assembly 32 condition, is the same as in the first embodiment aspect. Nevertheless, in cases where laser machining of the back surface 30 of the slider 1 is very difficult, if necessary, either laser machining, or milling or scribing with a diamond needle, etc., that can alter the stress conditions, may be implemented, from the air bearing surface 3 of the slider 1 , or from the back surface side of the gimbal 34 .
[0064] Based on a fifth embodiment aspect of the present invention, as diagrammed in FIG. 18, the flow of target curvature determination executed in the arithmetic processing unit 112 can be verified with numerical values or a graph with a data display unit 115 that can display [that flow].
[0065] A head gimbal assembly manufacturing method and manufacturing apparatus according to a sixth embodiment aspect of the present invention are described with reference to FIG. 19 and the flowchart given in FIG. 20. In this sixth embodiment aspect, there is no data input unit 111 a for inputting the load or static attitude data 110 a of the head gimbal assembly 32 as in the fourth embodiment aspect, and the target curvature calculation module 40 is configured only of the flying height predicting process 42 and the target curvature determination process 43 . The characteristic points in the sixth embodiment aspect are that there is a load and static attitude measurement process 52 b for measuring the load or static attitude data that is a feature of the curvature measurement unit 101 , and that those data are passed to the target curvature calculation module 40 . The other processes are the same as in the fourth embodiment aspect. By configuring the sixth embodiment aspect as described in the foregoing, the need for other shape measurement equipment is eliminated, the adjustment of the curvature of the air bearing surface 3 , taking variation in the load or static attitude of the head gimbal assembly 32 into consideration, can be realized with only the curvature adjustment apparatus, and a slider 1 of small flying height variation can be manufactured.
[0066] By adjusting the curvature of the air bearing surface according to the predicted flying height calculated while giving consideration to shape data such as slider channel depth and the like, magnetic head slider flying height variation can be reduced without narrowing manufacturing tolerances. Also, by adjusting the curvature of the air bearing surface according to the predicted flying height calculated from the pressing load or static attitude of the head gimbal assembly, head gimbal assemblies that exhibit small flying height variation can be realized. Furthermore, by reducing these flying height variations, the flying height of the magnetic head slider can be lowered.
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With negative pressure sliders having step bearings, there are variations in flying height resulting from variations in shape factors, such as the step bearing depth. In order to achieve lower flying height, it is considered necessary to reduce the variation in flying height caused by the variation in curvature of the air bearing surface and the variation in flying height caused by the variation in the shapes of the step bearings. The curvature of the air bearing surface of the slider can be observed in the pre-cut row bar condition or in a unit product condition. Shape data of the magnetic head slider can be input, such as the step bearing depth, etc., so as to calculate the predicted flying height of the slider An arithmetic processing unit calculates an adjusted target curvature from the difference between the predicted flying height and the target flying height.
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BACKGROUND OF THE INVENTION
This invention relates to sheet protectors, and more particularly to a tabulated sheet protector for use in an indexed refillable book, as well as a method for making such sheet protectors.
There are many areas which require use of a tabulated, indexed, refillable book. For example, a telephone director typically utilizes a series of tabulated, indexed pages with the tabs being identified by the letters of the alphabet. The tabs generally extend laterally from the pages of the book so that they can be easily selected and the book opened to the proper page. Frequently, diaries also utilize such tabulated pages with the tabs being identified by the names or numbers of the months. Many other types of books similarly utilize tabulated pages including recipe books, calendars, credit card directories and numerous others.
Many of these tabulated books utilize a looseleaf type binder with rings for holding the tabulated pages. The rings can generally be opened to permit the addition and/or removal of individual pages from the book.
By way of example, in a telephone directory, there can be a number of sheets provided within the looseleaf book with a sheet having a column for inserting the name, address, and telephone number of various individuals. Laterally extending from each sheet will be a tab identifying the particular letter of the alphabet relating to those names. Additional sheets bearing the same letter can be added. Alternately, additional sheets without any tabs can be added behind a particular indexed sheet having a tab with an identifying letter.
When utilizing such books, the sheets must be accessible for adding new entries into the directory, such as adding additional names and addresses. At the same time, they must be durable so as to sustain continued turning of pages, regular usage, rubbing against the pages, and similar harsh treatment. Also, the sheets should be of a type which can be easily removed and replaced within the binder.
One solution is to utilize sheet protectors for protecting the individual sheets. The sheets can be inserted or removed from the sheet protectors for adding or removal of names. At the same time, once inserted into the sheet protectors, the sheet itself will be protected so that continuous usage will not damage the sheet. However, the difficulty with utilizing such sheet protectors is that they must be readily insertable into the binder and additional sheet protectors should be available for easy insertion and removal from the binder. Additionally, the problem arises as to how to provide the tabulation for the sheets. If the sheets themselves are tabulated, then the tabs will extend beyond the sheet protector and the tabs will be damaged. If the sheet protectors are tabulated, the tabs will have a tendancy to rip off, or be separated from the sheet protectors. Additionally, a difficulty arises in how to retain the tabs onto the sheet protectors to provide a permanent and yet not mar the sheet protector nor disturb the attractiveness of the book.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a tabulated refillable book which avoids the aforementioned problems of prior art books of a similar nature.
A further object of the present invention is to provide a tabulated refillable book having a plurality of sheet protectors with each sheet protector formed with an integral tab.
Still another object of the present invention is to provide a tabulated refillable book having a plurality of transparent sheet protectors with each sheet protector having a laterally extending integral tab and with the various respective positions of the tabs on each sheet being sequentially indexed. A further object of the present invention is to provide a sheet protector formed of upper and lower layers of substantially transparent plastic material to define a sheet receiving pocket therebetween, and having a pair of complementary tabs laterally extending and integral with each of the layers.
Another object of the present invention is to provide a sheet protector formed of upper and lower layers of plastic material each having a matching tab portion laterally extending and integral therewith with the layers being sealed together through heat sealing means with the heat seal engraving an identification indicia on the tab.
Yet another object of the present invention is to provide a method for forming a sheet protector with an integral tab portion.
A further object of the present invention is to provide a method of forming a sheet protector formed of two layers by heat sealing together the two layers and simultaneously engraving an identification indicia in the tab portion using the same heat sealing procedure.
Briefly, in accordance with the present invention, there is provided a sheet protector formed of an upper and lower layer of substantially transparent plastic material. A pair of complementary tabs are provided with each tab laterally extending from the edge of a respective layer and integrally formed with that layer. Heat seals are formed for securing together at least a portion of the peripheries of the layers and also for securing together the matching tabs. An opening is formed in the layers for defining in combination with the layers a suitable pocket whereby a sheet may be inserted in the pocket.
The present invention also contemplates a method of forming a sheet protector by first obtaining an upper and lower layer of substantially transparent plastic material with each layer having an integral matching tab laterally extending from an edge thereof. The layers are then heat sealed together to that at least a portion of the peripheries of the layers are secured as well as the matching tabs being secured together.
An access is provided into the space between the layers to define a pocket whereby a sheet may be inserted into the pocket. An identification indicia is then impressed on the tabs.
In an embodiment of the invention, the identification indicia is formed in conjunction with the heat sealing step whereby the indicia is formed by means of heat seals impressed into the plastic material.
The invention further contemplates a tabulated refillable book having a looseleaf type binder with a plurality of rings positioned along a spine and levers for opening the rings. A number of the aforementioned transparent sheet protectors are supported by the rings. Individual sheets may be inserted into the protectors. The tab positions on the respective sheet protectors are sequentially indexed with respect to each other.
The aforementioned objects, features and advantages of the invention will, in part, be pointed out with particularity and will, in part, become obvious from the following more detailed description of the invention, taken in conjunction with the accompanying drawings, which forms an integral part thereof.
BRIEF DESCRIPTION OF THE DRAWING
In the drawings:
FIG. 1 is a plan view of the tabulated refillable book in an open position exposing various sheet protectors, in accordance with the present invention;
FIG. 2 is an exploded view of the upper an lower layers forming an individual sheet protector, and
FIG. 3 is a cross sectional view taken along lines 3--3 of FIG. 1, and specifically through one sheet protector.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIG. 1, the sheet protector of the present invention is shown generally at 10 and is positioned within a looseleaf binder, shown generally at 12. The looseleaf binder is of a standard type including a front cover 14 and a rear cover 16 interconnected by a spine portion 18. Located on the spine portion is a metal bar 20 supporting a purality of rings 22 having an interfitting split section 24 to permit opening of the rings. End levers 26, 28 are available for manipulation causing a spring mechanism within the bar section 20 to open the rings, as is well known. The bar section itself is retained onto the spine by means of rivets 30.
An overlying flap 32 is formed on the lower portion of the front cover to define a storage pocket therein, and a similar overlying flap 34 is formed on the rear cover 16 to similarly define a pocket therein.
The particular sheet protectors are formed of upper and lower layers 36, 38, as best shown in FIG. 2. The layers are formed of substantially transparent material, typically plastic such as vinyl or the like. The layers can be formed with a clear or satin finish, as long as it permits viewing of a sheet inserted therebetween. The upper and lower layers, 36, 38 are each substantially rectangular and almost identical in shape. However, the upper layer 36 has its longitudinal dimension slightly shorter than the lower layer 38. As a result, when the two layers are placed adjacent each other, the top edge 40 of the upper layer 36 will be spaced from the top edge 42 of the lower layer 38, as shown by the dotted line 44 in FIG. 2.
Laterally extending and integral with the upper layer 36 is the tap portion 46. A correspondingly shaped tap portion 48 is formed with the lower layer 38 and integral therewith. The two layers are paired and sealed together about their periphery by typical heat sealing mechanisms. All of the peripheral edges of the layers are sealed together with the exception of the top edges 40, 42. As a result, the two layers form a pocket therebetween for receiving a sheet therein.
More specifically, as shown in FIGS. 1 and 3, the upper layer 36 and lower layer 38 are placed onto each other, and utilizing heat sealing mechanisms three of the peripheral edges are secured together. The heat sealing mechanisms forms an indent at the point of fusion, as shown typically at 50. After the three peripheral edges are sealed together, an internal pocket 52 is formed. By displacing the top edges 40, 42 of the two layers, insertion of a sheet into the pocket 52 is facilitated. This can best be seen in FIG. 1 wherein insertion of the sheet 54 is facilitated by placing it between the edges 40 and 42.
Simultaneously with the sealing of the peripheral edges of the layers 36, 38, the peripheral edges of the tab sections 46, 48 are also heat sealed together at their semicircular peripheries. Additionally, an identifying indicia can be formed into the tab section by means of the heating sealing operation. The same indents which form the heat sealing channel around the periphery of the sheets can also form sections of the identifying indicia.
Specifically, as shown in FIGS. 1 and 3, individual alphanumeric letters have been formed in the tab sections by means of the heat sealing operation. Thus, the sheet on the left portion in FIG. 1 has the identifying letter A placed in its tab portion 54. Similarly, other of the tabs have other letters of the alphabet formed therein. As shown in FIG. 3, the specific indents 56 and 58 identify the letter D in the tab section 60 shown in FIG. 1.
During the formation of the letters or other indents, a sheet of material could be interposed whereby the letters or indents could be decoratively colored. For example, a sheet of gold leaf material could be used to provide a gold tint to the letters.
In order to insert the sheets into the looseleaf binder, a selvage section 62 is formed along the inner edge of the sheet protectors. The selvage section 62 is defined by means of the heat sealing indented channel 64 separating the pocket 52 from the selvage section 62. Within the selvage section, a plurality of holes 66 are formed with the peripheries of the holes being heat sealed together at 68. By means of the heat seal operation, the hole effectively becomes reinforced so it can be securely retained within the binder rings.
In order to utilize the sheets for indexing, the particular tab locations on successive sheets can be positioned in a sequential manner. Thus, the tab bearing the letter A is placed at the top of the sheets, and the next tab bearing the letter B is placed at a location spaced in sequence from the tab bearing the letter A. Similarly, the other tabs can be positioned so as to be spaced adjacent to each other so as to permit easy identification of the indicia formed thereon.
At the opposing ends of the selvage, the sheet itself is shown to include upper and lower shoulder portions 70 so as to permit easy access to the releasing levers 26, 28. The complete periphery of the selvage section is heat sealed so that all of the edges of the entire sheet protector are closed, with the exception of the top edges which give access to the pocket.
It should be appreciated, that all of the peripheral edges of the layers could be sealed together and a separate slit opening could be formed in one of the layers to give access to the pocket. Other access could also be provided.
In the particular embodiment shown, the booklet forms a telephone directory and the particular sheets 54 which are inserted in each of the sheet protectors are ones which have preprinted room for names, addresses, and telephone numbers. However, other types of sheets could be inserted into the sheet protectors and accordingly, other types of identifying indicia could be placed on the tabs. For example, the book could be utilized as a calendar with pages insertable representing the particular months of the year. Each page would have as indicia identifying the particular month. By means of the replaceable feature of the sheets, the same book could be continuously used year after year by simply replacing the sheets having the months printed on them. Additionally, the book can be used as a recipe book, a standard index, and similar types of books requiring tabulation and refillability.
With the embodiment as described, when an additional name must be entered, the particular sheet can be extracted from the sheet protector and the name added. The sheet is then replaced into the pocket between the layers forming the sheet protector. Furthermore, extra sheet protectors could be provided without having any tab on them for extra pages between adjacent tabs. Thus, between the tab A and B, if additional names having the letter A is required, additional sheets and sheet protectors without tabs could be placed between the A and B tabs for extra names with the Letter A. The front or rear book pockets 32, 34 can be used to hold extra sheets for insertion into the sheet protectors.
In forming the particular sheet protectors, the shape of the sheets can initially be cut as shown in FIG. 2 and these sheets then inserted in the heat sealing press. Alternately, the apparatus which provides for the heat sealing can simultaneously be utilized to cut the sheets to the particular size desired so that the cutting operation and the heating sealing operation are carried out in conjunction with each other.
There has been disclosed heretofore the best embodiment of the invention presently contemplated. However, it should be understood that various changes and modifications may be made thereto without departing from the spirit of the invention.
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A sheet protector formed of upper and lower layers of substantially transparent plastic material. A pair of complementary tabs each laterally extending from the edges of the respective layers are integrally formed therewith. Heat sealing is utilized for securing together at least some of the peripheries of the layers as well as the matching tabs. An opening is provided to define in combination with the layers a receiving pocket whereby a sheet may be inserted in the pocket. A looseleaf type binder is provided for holding a plurality of the sheet protectors. The tab positions of the respective sheet protectors in the binder are sequentially indexed with respect to each other to provide a set of position selectable sheet protectors.
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FIELD OF THE INVENTION
[0001] The invention pertains to the field of cosmetic containers and more particularly display devices which show application of cosmetic products.
BACKGROUND OF THE INVENTION
[0002] Display of some personal care products and cosmetics often require the viewer to take an imaginative leap in visualizing, let alone fixating, what the particular product displayed would look like as applied to their own face or body. Applying sample products is not always available or convenient, and sampling a number of products at one sitting may prove difficult. Store displays, purchasing aids, and advertisements may illustrate cosmetic colors, but the question of how these colors may combine with a user's facial tones or how they may appear in combination with other cosmetics is usually left to the purchaser's imagination. Moreover, manipulable aids such as color wheels and the like may be nearly overwhelming in their presentation of so many colors and nonetheless operate in a context that makes it difficult to visualize their actual color and effect on the wearer. Cosmetics are unique in that their optimal use may usually rely on contrasting colors on a particular foundation where the ultimate colors and tone of which are heavily dependent on the user's complexion and other facial features for its effect. Some apparatus and/or method of reproducing this effect for a potential wearer without having to “try-on” numerous cosmetic compounds would find significant use.
[0003] This application uses the wording “Cosmetic Products” or “Cosmetics” broadly to encompass, without limitation, beautifying, enhancing, cleansing, covering and/or medicinal compounds which may be applied to a wearer's body, or portion thereof, especially those exhibiting a particular ornamental color, shade or tone on the wearer. “Facial Design” is likewise used broadly in this application to encompass a body portion of a human which may derive benefit from use of cosmetics and which may illustrate particular colors, tones and complexions, was well as features exemplified by facial elements such as nose, eyes, lips and cheeks, but by no means so limited to such features.
SUMMARY OF THE INVENTION
[0004] What is disclosed is an apparatus and method for displaying and packaging cosmetic items. The display case apparatus for cosmetics and other personal care products comprises a housing having an overall shape defining a peripheral edge; a retainer defining a plurality of interstices, said retainer coupled to said housing such that it is co-extensive with at least a portion of the housing peripheral edge, said retainer having a front whereupon a design is visible whereas the plurality of interstices are disposed at pre-determined portions of the design; at least one holding compartment disposed within at least one retainer interstice for receiving an article. The method comprises the steps of providing a design corresponding to a human body portion having pre-determined colors, the design defining interstices at locations in the design corresponding to pre-determined body part segments and disposing within the interstices cosmetic and personal care containers of a pre-determined color or shade complimentary with the pre-determined body part segment.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] [0005]FIG. 1 a illustrates a facial design exhibiting one complexion of an exemplary embodiment of the invention.
[0006] [0006]FIG. 1 b illustrates a facial design exhibiting another complexion of an exemplary embodiment of the invention.
[0007] [0007]FIG. 1 c illustrates a facial design exhibiting yet another complexion of an exemplary embodiment of the invention.
[0008] [0008]FIG. 1 d illustrates a facial design exhibiting still another complexion of an exemplary embodiment of the invention.
[0009] [0009]FIG. 2 illustrates a facial design exhibiting cosmetic compartments in one embodiment of the invention.
[0010] [0010]FIG. 3 illustrates an alternative embodiment of the invention indicating shapes and positions of cosmetic compartments in a facial design.
[0011] [0011]FIG. 4 illustrates an alternative embodiment of the invention featuring a facial design with surrounding cosmetic compartments.
[0012] [0012]FIG. 5 illustrates an alternative embodiment of the invention featuring a facial design and cosmetic compartments contained within a travel case.
[0013] [0013]FIG. 6 illustrates one housing configuration of the invention.
[0014] [0014]FIG. 7 illustrates and alternative housing configuration of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0015] With respect to the figures provided, illustrating one embodiment of the invention, FIGS. 1 a , 1 b and 1 c illustrate facial designs which are reproductions of various facial types, including complexion types, allowing a user to more clearly approach their own facial structure and complexion. These facial designs provide the basis for the display or packaging of various cosmetics, allowing these cosmetics to be viewed in relation to a particular complexion against which they may be compared and/or contrasted either alone or in various combinations. The facial designs feature facial types available that may be selected from a representative assortment or may be customized to an individual's particular facial structure and complexion. Preparation of such a facial design may be derived from a profile, whether generic or customized, based on a photograph, digitized image, artist's rendering, or any combination thereof or in other ways of graphic reproduction known in the art. The drawings illustrate use of artist renderings.
[0016] [0016]FIG. 1 a illustrates facial design with fair skinned, blond haired features; FIG. 1 b a facial design with an ebony complexion with dark hair; FIG. 1 c illustrates a facial design with a medium complexion and red hair; and FIG. 1 d illustrates a brunette haired medium dark complexion facial design. It is to be appreciated that numerous variations and complexions may also be illustrated and/or customized in a facial design. The facial designs each exhibit sufficient surface area for skin, eyes, lips, eyebrow, hair, cheeks, ears and nose to also accommodate application of a cosmetic product that may be applied to each area. Other areas, such as neck, forehead, upper and lower eyelashes, eyelids and any other facial or body features may also be illustrated and similarly presented for the application of particular cosmetics. In the figures, an artists rendering of a face is illustrated, but, as stated previously, this may be any one of a combination of digitized image, photograph or otherwise. For instance, the facial design may be derived from a photograph which is retouched to elongate or distort facial features to provide sufficient space for the application of cosmetics or personal care products of varying styles and colors while maintaining the original complexion for purposes of comparison and demonstration. The artistic display possibilities and renderings for the facial design are therefore unlimited and may be prepared according to the methods known in the art.
[0017] The facial design is applied to a surface, which may be composed of various polymer plastics or other material retaining sufficient tensile strength to support integrated interstices wherein containers of cosmetics are disposed. This surface may be placed within a housing that basically comports to the overall shape of the surface. The surface upon which the design appears is either of sufficient durability and strength to retain and hold compartments defined within interstices in the surface into which will be received containers having reservoirs of cosmetics. Alternatively, the facial design may be applied to a surface within a housing over which a transparent retaining layer may be placed, where the design is visible through the retaining layer and the retaining layer otherwise has the properties of the surface previously described, i.e. strength and durability to receive reservoir containers into interstices defining compartments.
[0018] [0018]FIG. 2 illustrates a particular facial design 10 of one embodiment of the invention where a plurality of interstices (not pictured) are defined within the facial design surface, or within an intermediate transparent layer placed over the facial design surface, provide areas for cosmetic containers to be received, so as to provide a comparison or contrast with the overall complexion, hair color and/or facial features of the design, whether that design is of a specific individual or of a generic type. The cosmetics are thus held in place by a retainer comprising either the facial design surface or the intermediate transparent layer with an underlying facial design surface visible therethrough. Thus, powder 12 may be inserted in a corresponding powder interstice (not pictured) on cheek 15 to allow for the comparison of the powder color with the particular skin color 20 . Blush 21 may be placed on the opposite cheek 16 from powder 12 to allow its view in isolation from other applications yet allowing a direct comparison to the overall complexion of the figure or any desired contrast from powder 12 . Foundation 17 may be placed on nose 19 to highlight its use as close to the corresponding site of use for the face of a use. Similarly, interstices for shadow 22 , eye liner 23 , concealer 24 , eye brow pencil color 26 and hair brush 28 may also be included, among other types of products that may be applied to the figure depicted.
[0019] Lips 33 may include interstices for an upper 34 and lower lip 35 segments. In one embodiment, this division of lip 33 interstice may provide openings for the placement of gloss 37 and lipstick 38 . The gloss portion may already have a base lipstick color to heighten the visual effect of any gloss applied thereto. Actual containers (not pictured) of lipstick and lip gloss, as with other application products depicted on the face design, may occupy the lip 33 interstices, divided into segments 34 and 35 , and may be freely removable therefrom, as will be further described in later figures, to allow demonstration and view of a number of different application products according to their colors and tones in comparison/contrast with the overall tone and complexion of the facial design 10 .
[0020] Interstices may have shapes and sizes sufficient to manipulate and replace cosmetic containers therein. In the embodiment illustrated, the interstices (not pictured) have the size and shape of the simulated facial design features themselves. For instance, concealer 24 interstice and reservoir occupies the lower eye region at the point where concealer 24 would be utilized on a user's face. Similarly lips 33 interstices conform to the basic shape of human lips. The invention, however, is not limited to providing interstices, containers or reservoirs which are shaped according to the facial feature or element of the corresponding application product. For instance, the interstices for powder 14 may be small circular interstices within an area defined by powder 14 on facial design 10 . Into these interstices may be received containers bearing the powder reservoir which may alternatively be open to allow the cosmetic powder to be accessed and applied, covered with a transparent cover to view the cosmetic powder, or covered with an opaque cover bearing a reproduction of the powder color within the container.
[0021] One or more interstices, moreover may be provided for powder at various portions of the facial design to allow the user to move the application to other areas for comparison/contrast with the overall complexion or color of the face, or to place separate colored powders in each interstice to compare and contrast the use of multiple color powders in combination on facial design 10 . Similarly, shadow interstices need not be eyeshaped or semi-eliptical, but may be round, square, triangular or any other type of shape so long as the interstices accept a similarly shaped container or reservoir of the application product that will be placed within.
[0022] [0022]FIG. 3 illustrates one embodiment of the facial design as provided with containers for various cosmetics situated approximately at a facial element depicted on the facial design. In this embodiment, the location of the cosmetic containers pertain to interstices located at the depicted facial element that the particular cosmetic is likely to be applied by a user. For instance, foundation 61 , occupies the nose section, and, in this embodiment, features a nose shaped container. Translucent face powder 62 occupies the lower facial design near the chin element. Various containers for different eye shadows 64 - 67 may be incorporated on the eyebrow location of the facial design. Other containers, 68 - 80 , are similarly listed and situation on the facial design as shown in FIG. 3.
[0023] The containers themselves may be shaped in accordance with their location and use on the facial design. Hence, container 62 a for the translucent face powder conforms to at least a portion of the shape of the facial element and fits in a corresponding size interstice located at that portion of the facial design. Container 62 a has a depth for holding a pre-determined amount of cosmetic, in this instance translucent face powder. Similarly, container 67 a for eye shadow also has a shape conforming to a portion of the corresponding facial element, in this case the eyebrow, and has a depth for holding a pre-determined amount of eye shadow. In this embodiment, containers 62 a and 67 a would generally have a bowl like shape for holding cosmetic products which may include a surrounding lip rim to rest on the facial design surface surrounding the interstice in which it would be received. Corresponding containers 68 - 80 for other facial elements would generally follow the same basic composition as those described for containers 62 a and 67 a, e.g. they would conform to the applicable interstice located at the particular facial element and the containers would have depths to hold an effective pre-determined amount of cosmetic product.
[0024] [0024]FIG. 4 illustrates yet another embodiment of the invention, wherein the interstices within the facial design are accompanied by other interstices wherein other cosmetic products and applicators may be disposed. For instance, brushes and applicators 50 of various sizes for various functions, as well as lip and eyeliner pencils 55 and mascara applicators 58 may be placed around the facial design to make up the overall package, along with the actual cosmetics to be applied disposed at the appropriate location, within interstices where holding compartments are disposed to hold any containers therefor, on the facial design. FIG. 5 illustrates an alternative embodiment, where the display is in compact form for travel. Brushes and applicators may be positioned on a cover opposite the facial design, which is folded over to cover the facial design to form a case when not in use.
[0025] [0025]FIG. 6 illustrates a possible configuration of one embodiment of the invention whereby the facial design and interstices are coordinated in a single unit case. Case 100 accommodates a transparent molded tray layer containing interstices (not pictured) for receiving and retaining cosmetic containers. On the case inner cover, disposed below the tray, is the facial design portrait which, when the tray is placed thereover, is visible through the tray. The interstices within the tray correspond to the particular location of the product, e.g. blush container over the cheeks, eyeliner container over the eyes, such that superimposing the cosmetic color, visible either as applied to an outer covering of the container or by viewing the actual cosmetic product itself (utilizing, for instance, a removable transparent plastic cover), over the facial design provides the point of comparison and contrast for the user with respect to each cosmetic product that may be interposed within the tray (as stated earlier, this embodiment may also allow for interchanging of cosmetic containers).
[0026] [0026]FIG. 7 illustrates an alternative configuration of one embodiment of the invention. Wherein the case accommodates a transparent retaining layer that includes magnets at the bottom of each interstice to receive and hold the containers, which may be either fully or partially made of metal to allow for magnetic attraction within the interstices. As with the embodiment in FIG. 6, the facial design appears below the transparent layer, so as to be visible to a viewer.
[0027] While the invention has been described in respect to the above embodiments of the invention, it should be understood that the invention is not limited to these precise embodiments. Rather, many modifications and variations will present themselves to persons skilled in the art without departure from the scope and spirit of the inventions, which is defined in the appended claims.
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An apparatus and method for displaying and packaging cosmetic items. The display case apparatus for cosmetics and other personal care products comprises a housing having an overall shape defining a peripheral edge; a retainer defining a plurality of interstices, said retainer coupled to said housing such that it is co-extensive with at least a portion of the housing peripheral edge, said retainer having a front whereupon a design is visible whereas the plurality of interstices are disposed at pre-determined portions of the design; at least one holding compartment disposed within at least one retainer interstice for receiving an article. The method comprises the steps of providing a design corresponding to a human body portion having pre-determined colors, the design defining interstices at locations in the design corresponding to pre-determined body part segments and disposing within the interstices cosmetic and personal care containers of a pre-determined color or shade complimentary with the pre-determined body part segment.
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[0001] This application is related to and claims priority from U.S. provisional application No. 60/664,282. Application No. 60/664,282 is hereby incorporated by reference.
BACKGROUND
[0002] 1. Field of the Invention
[0003] The present invention relates to drywall taping tools and more particularly to a drywall taping tool with a powered cutter.
[0004] 2. Description of the Prior Art
[0005] There are many automatic drywall taping devices in production today that are commonly called BAZOOKAs (BAZOOKA is a registered trademark). Normally tools of this type have a tape (or paper) cutter incorporated into the design. This cutter is usually activated by pulling a movable tube down against a spring. This requires a movement of the arm while holding the bazooka. This can be very difficult in tight spots, at odd angles or when reaching high up joints.
[0006] It would be advantageous to have a drywall taping tool that converted this same type of cutting mechanism into a powered, trigger activated, auto cutter.
DESCRIPTION OF THE FIGURES
[0007] FIG. 1 shows a side view of the tool in the idle position.
[0008] FIG. 2 shows a Section C-C from FIG. 1 .
[0009] FIG. 3 shows Detail F from FIG. 1 .
[0010] FIG. 4 shows the tool in the cocking position.
[0011] FIG. 5 shows Section C-C from FIG. 4 .
[0012] FIG. 6 shows the tool in the cocked and ready position.
[0013] FIG. 7 shows Section C-C from FIG. 6 .
[0014] FIG. 8 shows Detail F. from FIG. 6 .
[0015] FIG. 9 shows the tool in the triggered and cut position.
[0016] FIG. 10 shows Section C-C from FIG. 9 .
[0017] FIG. 11 shows Detail F. from FIG. 9 .
[0018] Several drawings and illustrations have been presented to aid in the understanding of the invention. The scope of the present invention is not limited to the figures.
SUMMARY OF THE INVENTION
[0019] The present invention relates to a drywall taping tool that includes a standard drywall taping tool such as a BAZOOKA tool with an elongated handle, a tape cutter mounted on a distal end of the taping tool, wherein drywall tape passes through the tape cutter, and a trigger mounted on said elongated handle where the trigger causes the tape cutter to cut said drywall tape. The drywall taping tool of can be spring powered, hydraulic powered, electric powered or otherwise powered.
DESCRIPTION OF THE INVENTION
[0020] The present invention relates to a drywall tape dispensing tool with a powered auto cutter. This auto cutter uses the stored energy of a spring to do the cutting once the operator has depressed a trigger, normally with one finger. No arm motion is normally required to make the cut. This allows the operator to keep the tool precisely positioned at any angle, height, especially in tight spaces. The auto cutter can be cocked (ready for the next cut) while moving from one joint to the next joint.
[0021] The present invention is not limited to a spring powered cutter, rather the cutter may be powered by any means such as pneumatic, hydraulic, electrical, or any other power source.
[0022] Turning to FIG. 1 a side view of a taping tool is seen. This view shows a side view of the entire tool in the Idle position (not cocked, piston & pin assembly is up). On this view you can see where section C-C is located for the creation of FIG. 2 .
[0023] FIG. 2 shows section C-C as derived from FIG. 1 . Section C-C shows mainly the pertinent parts and assembly(s) needed for an understanding of the present invention. The tool is shown in the idle position.
[0024] FIG. 3 shows Detail F as derived from FIG. 2 . Detail F shows the latch 10 and triggering cable 12 in the idle position.
[0025] FIG. 4 shows a side view of the entire tool in the Cocking position as will be described.
[0026] FIG. 5 shows section C-C again, as derived from FIG. 4 while the tool is in the Cocking position. In FIG. 5 can be seen more clearly that the slider assembly 4 has been pulled down. Doing this pulls down the piston & pin assemble 8 until it is captured by the latch 10 . During this motion the piston & pin assembly 8 pulls the piston chain 5 which pulls the blade carrier 1 to the left end of the blade guide 2 . The movement of the blade carrier 1 pulls the spring chain 6 which pulls on the spring 3 , extending it.
[0027] FIG. 6 shows a side view of the entire tool in the cocked & ready position as will be described.
[0028] FIG. 7 shows section C-C again, as derived from FIG. 6 , while the tool is in the cocked & ready position. That means the sliding tube 4 has been raised leaving the piston & pin assembly 8 captured by the latch 10 and ready to be triggered. In this position the tool is ready to cut. A cut is initiated by pushing down on the trigger 13 . This pulls a the trigger cable 12 which runs the length of the tool body 7 and pulls up on the latch 10 .
[0029] FIG. 8 shows Detail F, as derived from FIG. 7 , which is a detail view of the latch 10 , trigger cable 12 , piston & pin assembly 8 and the slider assembly 4 , in the cocked & ready position.
[0030] FIG. 9 shows a side view of the entire tool in the Triggered & Cut position as will be described.
[0031] FIG. 10 shows section C-C as derived from FIG. 9 , in the Triggered & Cut position. In the Triggered & Cut position the catch has been rotated away from the cylinder & pin assembly by pulling on the trigger cable 12 which is routed down the tool main body 7 to the trigger 13 . Once the trigger 13 is depressed, the trigger cable 12 is pulled which pulls on the catch 10 rotating it away from the cylinder & pin assembly 8 . This rotation of the catch 10 releases the cylinder & pin assembly 8 . The spring 3 tension pulls spring chain 6 which pulls the blade carrier 1 to the right side of the blade guide 2 instantly pulling the blade across the path of the taping product which is held in place by the product guide 11 . The taping product is cut instantly by depressing the remote trigger. During this motion the blade carrier 1 pulls the actuation chain 5 which pulls the cylinder & pin assembly 8 up. The system ends up in the idle position.
[0032] FIG. 11 shows Detail F as derived from FIG. 10 , which is a detail view of the latch 10 , trigger cable 12 and the slider assembly in the Triggered & Cut position.
[0000] Operation
[0033] The blade carrier 1 which holds the cutting blade and slides through a blade guide 2 which spans the width of the tool and across the path, and up against the taping product which is held in this position by a product guide 11 . A chain is attached to each end of the carriage 1 which is used to pull the blade carriage 1 from one end of the guide 2 to the other end cutting the taping material as it moves. Attached to one side of the carriage 1 is a spring chain 6 that leads around a pulley 14 to a spring 3 which is anchored to the main tool body 7 . On the other side of the carriage an actuation chain 5 is attached which leads around another pulley 15 to a sliding tube assembly 4 that the operator holds onto during operation. The sliding tube assembly 4 is concentric with the main tool tube 7 and has rollers allowing it to be freely moved up and down a portion of the main tool tube 7 . With the chain attached to this sliding tube assembly 4 the operator can pull the actuation chain 5 , which pulls the blade carriage 1 through the guide 2 which pulls the spring chain 6 stretching the spring 3 at the other end of the chain. The blade carriage 1 slides through the blade guide 2 , across the path of the taping product which is held in place, next to the blade guide 2 , by the product guide 11 , cutting the taping product. This is done against the resistance of the stretching spring 3 which is anchored to the main tool body 7 . When the operator releases the sliding tube assembly 4 the spring 3 pulls the assembly back to its original position.
[0034] The present invention incorporates a latch and trigger mechanism into the prior art taping tool mechanism. An actuation chain 5 is attached to a piston & pin assembly 8 . The piston and pin assembly slides freely inside a cylinder 9 with the pin of the cylinder & pin assembly 8 running in a slot on the side of the cylinder 9 . The movable tube 4 is adapted to hit the piston & pin assembly 8 on the pin. When the movable tube 4 is pulled down (the same motion currently made when cutting with prior art taping tools) it hits the piston & pin assembly 8 causing it to slide down the cylinder 9 . This pulls the actuation chain 5 , which moves the blade carriage 1 along the guide 2 , which pulls the spring chain 6 , stretching the spring 3 . When the movable tube 4 is pulled far enough down the piston & pin assembly 8 engages the catch 10 until the catch 10 drops into a step in the side of the piston & pin assembly 8 . This captures the piston & pin assembly 8 .
[0035] The sliding tube assembly 4 is then raised back up to it's original position beyond vertical travel of the piston & pin assembly 8 . The tool is now cocked and ready to cut. The operator uses the bazooka as he normally would to apply joint compound and tape to the joint. At the end of the joint the operator depresses the trigger lever 13 which pulls the trigger cable 12 . The other end of the trigger cable is attached to the latch 10 and when the trigger cable 12 is pulled it rotates the latch 10 until it releases the cylinder & pin assembly 8 . Once the cylinder & pin assemble 8 is free, the spring 3 which has been pulling on the system pulls the blade carrier 1 along the blade guide 2 across the path of the taping material. This happens instantaneously. The tool can then be cocked again and is ready for the next joint.
[0036] Several descriptions and illustrations have been presented to aid in understanding the present invention. One skilled in the art will realize that many changes and variations can be made without departing from the spirit of the invention. Each of these changes and variations is within the scope of the present invention.
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A drywall tape or trim dispensing tool of the type similar to those sold under the name BAZOOKA with an elongated handle and a tape or trim dispensing head. The head can contain a blade coupled to a power mechanism such as a spring, hydraulic or electric energy source where the blade can be placed into a cocked position by a cocking mechanism and then triggered by a pull on a remote trigger located on the handle. After the device is cocked, the user can dispense tape or trim to a desired length and then cut it exactly by a simple trigger pull.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part of U.S. patent application Ser. No. 10/077,920 filed on Feb. 20, 2002, which claims priority from U.S. Provisional Patent Application Ser. No. 60/326,004 under 35 U.S.C. §119(e). This application claims priority from U.S. patent application Ser. No. 10/077,920 under 35 U.S.C. §120 and from U.S. Provisional Patent Application Ser. No. 60/326,004 under U.S.C. §119(e).
FIELD OF THE INVENTION
[0002] The present invention relates to equipment, commonly referred to as “feeders”, for dispensing finely divided particulate materials that are flowable. In particular this invention relates to an apparatus and a method for removing interstitial air between the particles of finely divided particulate materials while they are being dispensed through a feeder.
BACKGROUND OF THE INVENTION
[0003] Many continuous processes that include adding finely divided particulate materials, such as silica, carbon black, and other fillers, are typically rate-limited by the volume addition of those materials. In part, this is because most finely divided particulate materials interstitial and entrained air, and have a large part of their volume represented by air. For this reason there have been attempts to remove the air by vacuum, and/or densify the finely divided particulate material by mechanical means such as shaking or compacting.
[0004] U.S. Pat. No. 3,664,385 to Carter teaches an apparatus and a method of compacting finely divided particulate material which uses a first rotating screw feeder for advancing the material along a housing having a tubular sleeve mounted within the housing. The sleeve and housing define a closed hollow chamber, extending about the sleeve with a plurality of perforations in the sleeve. Suction is applied chamber so that air can flow from the sleeve to the chamber. Intermittent air pressure is applied to the chamber to back-flush particulate material from the perforations. The particulate material, which is densified in the first rotating screw, is then mechanically advanced along the second sleeve passage to a container filling station.
SUMMARY OF THE INVENTION
[0005] The present invention is a feeder that removes interstitial air from finely divided particulate materials by creating a compression force counter to the material feed direction, allowing pressure to build up while the finely divided particulate material is transported through a housing and then venting air from the housing.
DETAILED DESCRIPTION OF THE INVENTION
[0006] The feeder of the present invention is suitable for removing interstitial air from a variety of finely divided particulate materials, such as fluffy powders or mineral fillers used in the rubber and coating industry. In the present invention, finely divided particulate material enters a cylindrical housing ( 1 ) at an inlet ( 2 ) located near one end of the cylindrical housing. In a preferred embodiment, the finely divided particulate material is fed into the inlet ( 2 ) from a hopper ( 3 ), and a weighing device on the hopper, or a flow meter placed between the hopper and the inlet, measures the flow rate of the finely divided particulate material as it moves through the inlet ( 2 ). The use of a weighing device or flow meter allows for the feeder to be used in a continuous process where an amount of finely divided particulate material needs to be delivered at a constant or known rate.
[0007] The finely divided particulate material is conveyed along the length of the cylindrical housing ( 1 ) by a helix ( 4 ) within the housing that is driven by a motor to rotate coaxially to the cylindrical housing. The helix can be a coil or a screw with threads. When a coil is used to advance the material, it is often called a pigtail. When a screw with threads is used, the threads of the screw can be either convex (as an auger) or concave in shape. Some feeders use a single screw. Other feeders use two screws, with the helix of the first screw offset so as to intermesh with the helix of the second screw. This type of feeder is called a “twin-screw”. The screws of the twin-screw extruder can rotate in the same direction (co-rotate), or in opposite directions (counter-rotate). For the feeder of this invention, a co-rotating twin screws with concave threads are preferred. When a twin-screw feeder is used, the finely divided particulate material is turned over more times, exposing more surface and interstitial air to the pressure differential. The concave threads are preferred because the finely divided particulate material is pushed with at force more normal to the walls of the cylindrical housing than would be typical for convex or auger designs. The size of the feeder, the size of the screw, and the power to drive the rotation of the screws are dependent on the material to be dispensed, as well as the speed with which dispensing is required.
[0008] The feeder of this invention uses compression force on the feeder to generate pressure to force interstitial air out of the finely divided particulate material. The compression force is created as the finely divided particulate material is conveyed along the helix ( 4 ) within the cylindrical housing ( 1 ), and is discharged through an outlet ( 5 ) against an end plate ( 6 ) held in place against the flow of the finely divided particulate material with a compression screw ( 7 ).
[0009] The compression force generates a differential pressure between the inside of the feeder housing and the pressure outside the feeder, usually atmospheric pressure. The pressure forces the interstitial air through a vent ( 8 ), removing it from the finely divided particulate material. This increases the density of the finely divided particulate material. Without being tied to any one theory, the inventors believe that an increase in density is a function of the compressive force, the vent area, and the flow rate of the finely divided particulate material through the feeder. The compressive force should be optimized. Excessive compressive force leads to plugging, potential silica damage, and feeder instability due to inadequate pumping capacity. Too little force creates inadequate differential pressure. Maximizing the vent area allows lower compressive force and maximizes the vent capacity. Higher flow rates result in less density improvement because of the increased air volume. To get higher rates, the feeder screws rotate faster, resulting in less residence time in the event area, and therefore less air can be vented. To achieve the maximum benefit, feeders with larger diameter screws are required. Larger diameter screws would be used to increase the volume per revolution of filler, resulting in lower screw speeds, and more residence time in the vent area.
[0010] In a preferred embodiment, the outlet ( 5 ) is located between the housing ( 1 ) and the plate ( 6 ), so that the finely divided particulate material exits radially to the axis of the helix. The direction of the flow of the finely divided particulate material after it has traveled through the outlet can then be directed by any conventional means.
[0011] The plate ( 6 ) is held in place by one or more compression springs. The compression spring can be adjusted to adjust the pressure against the flow of the finely divided particulate material. The springs allow the plate to move slightly as the force against the plate increases. The use of springs reduces or prevents seizing of the feeder from over-compression of the finely divided particulate material. Other means for providing compression on the plate that are suitable for this invention include cams, elastic bands, cantilevered weights and the like.
[0012] Preferably, between the outlet ( 5 ) and the end plate ( 6 ) is a restrictor plate ( 9 ). The restrictor plate directs the flow of the finely divided particulate material from the chamber with the helix, reducing the cross-sectional area of the flow as the finely-divided particulate material from the cylindrical housing, through a tapered surface, such as a partial cone, toward the center of the plate ( 6 ). The tapered surface distributes pressure to the center of the plate, creating an isotropic pressure gradient over the face of the plate. The angle of the tapered surface, from the inside diameter of the cylindrical housing ( 1 ) to the plate ( 6 ) can be from about 5° (nearly parallel to the axis of the cylindrical housing) to about 85° (nearly perpendicular to the axis of the cylindrical housing). If an insufficient taper used, the finely divided particulate material tends to compact. If the taper is too narrow (i.e. too close to 90°) there will be too much compression force directed back to the outlet, causing compacting at the outlet. Preferably, the tapered surface is a right centered cone, with the tapered surface at an angle of between 5° and 60° and more preferably between about 30° and 45° from parallel to the axis. The exact angle that is useful for each machine will be determined by simple experimentation.
[0013] In the feeder of the present invention, the housing is fitted with a vent ( 8 ). The vent allows air to escape the feeder while retaining the finely divided particulate material in the feeder. In one embodiment, a conventional vent with a filter is attached to the feeder housing perpendicular to the axis of the screw. In a preferred embodiment, the vent is constructed by using sintered metal as the housing material for a section of the housing. By using a sintered metal housing, there is less buildup of finely divided particulate material at the vent surface. Air transport through some particulate materials, such as silica or mica, can be quite slow. The area of venting will be determined by the desired flow rate and compression of the material.
[0014] To maximize the removal of interstitial air, the flow rate of the finely divided particulate material should be optimized to maximize residence time and exposure to the pressure differential, while maintaining an acceptable flow rate for the process that the feeder is supplying. Too high of a flow rate requires faster feeder screw speeds, resulting in less residence time for venting.
[0015] While the feeder of the present invention is designed to use compressive force to push interstitial air out of the finely divided particulate material through a vent, it is possible to use vacuum to assist the airflow. In an embodiment using vacuum in addition to compressive force, a second housing would be fitted around the cylindrical housing. On the second housing would be a vacuum port through which air would be removed from the space defined between the cylindrical housing and the first housing. Another advantage of having a second housing surrounding the cylindrical housing is that it would allow the filtering surface to be easily cleaned through a pulse back of air through the sintered metal.
EXAMPLES
Example 1
[0016] A device of the present invention was constructed to remove air from silica having bulk densities ranging from 35 to 70 g per liter. This design a maximum of 5 N of compressive force on an area of approximately 0.002 m 2 (3.53 in 2 ) creating about 2.5 kPa (0.4 psi) of discharge pressure. A vent area of about 0.015 m 2 (24 in 2 ) results in adequate venting capacity to effectively increase the silica density at rates up to 45.5 kg/hr (100 lb/hr). The resulting silica bulk density was about 100 g/L. The silica in this example was discharged to a silicone compounder for making a curable silicone composition.
[0017] The device of Example 1 increases the silica density and reduces density variation. As shown in FIG. 3, the average density increased by 17.8% and the operational density increased by 28.5% over a feeder refill cycle. The operational density is the density the compounding process would have to operate at to prevent overfilling (Flooding) the compounder. Compounder flooding leads to waste and/or poor product quality because the process is shutdown or the material is produced with varying levels of silica.
[0018] Compressive Force
[0019] The effect of compressive force on the compression screws of the device on density was measured. This data is from the device configuration of example 1Optimum compressive force for the design if example 1 is approximately 5 N. FIG. 4 shows the impact of excessive and insufficient compressive force.
[0020] Vent Area
[0021] [0021]FIG. 5 shows that maximizing the vent area allows lower compressive force and maximizes the vent capacity.
[0022] Flow rate
[0023] The effect of flow rate of M7-D silica through the device of EXAMPLE 1 on the resulting density was measured. The results can be seen in FIG. 6.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] [0024]FIG. 1 shows an apparatus of the present invention having
[0025] 1. a cylindrical housing,
[0026] 2. an inlet to the housing,
[0027] 3. a hopper that feeds finely divided particulate material to the inlet,
[0028] 4. a helix driven by a motor, the helix installed so that it can axially rotate within the cylindrical housing,
[0029] 5. an outlet,
[0030] 6. an end plate mounted perpendicularly to the outlet at a distance to allow finely divided particulate material to discharge from the outlet against the plate and radially from the axis of the cylindrical housing,
[0031] 7. compression screws holding pressure against the end plate,
[0032] 8. a vent located on the cylindrical housing, the vent providing fluid communication between the interior of the cylindrical housing and the exterior of the cylindrical housing by means of openings having a smaller diameter than the diameter of the particulate material, and
[0033] 9. a restrictor plate mounted to the outlet.
[0034] [0034]FIG. 2 shows an example of a silica de-airing process using the device of the present invention.
[0035] [0035]FIG. 3 shows the reduced density variation and the density increase of silica using the device of the present invention.
[0036] [0036]FIG. 4 shows density as a function of flow rate and compression.
[0037] [0037]FIG. 5 shows air vented as a function of compressive force for two vent sizes.
[0038] [0038]FIG. 6 shows silica density as a function of flow rate through a device of the present invention.
[0039] [0039]FIG. 7 shows a cutaway perspective view of a portion of an apparatus of the present invention having:
[0040] 1. a housing,
[0041] 2. an inlet to the housing,
[0042] 3. a hopper that feeds finely divided particulate material to the inlet,
[0043] 4. a helix, the helix installed so that it can axially rotate within the housing, where the helix comprises
[0044] 11. a first threaded screw inside the housing, and
[0045] 12. a second threaded screw inside the housing, wherein the first threaded screw has threads offset from and intermeshed with the threads of the second threaded screw and where the first threaded screw and the second threaded screw have
[0046] 13. concave threads.
[0047] [0047]FIG. 8 shows a photograph of a portion of the housing 1 of the apparatus in FIG. 7. The housing 1 has a sintered metal vent 10 .
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An apparatus for removing air from finely divided particulate material comprises a housing including a vent; an inlet to the housing; an outlet from the housing; a helix, rotatably mounted in the housing, the helix being adapted upon rotation to feed a particulate material from the inlet to the outlet; a motor mounted to the helix for the purpose of rotating the helix; and a compression assembly mounted to the outlet for compressing the particulate material passing through the outlet.
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BACKGROUND OF THE INVENTION
The invention relates to a viscous coupling having a first coupling part designed as a housing, a second coupling part designed as a hub, at lest two sets of coupling plates, with the first set being non-rotatingly connected to the coupling housing and the second set(s) being non-rotatingly connected to the coupling hub, with the two sets being arranged so as to alternate axially, with at least one set of coupling plates being axially movable to a limited extent, and the remaining interior space being at least partially filled with a viscous fluid whose pressure may be predetemined by a controllable pressure generator consisting of a piston/cylinder unit.
A viscous coupling having a pump for conveying the viscous medium is known from GB 22 02 602 A. The design as described in the patent specification includes a piston pump which permits the internal pressure in the viscous coupling to be changed, with the maximum pressure and the predeterminable pressure being set by two control valves. One of the disadvantages of this design is that as a result of the abrasion of the coupling plates, the viscous fluid is polluted to an increasing extent.
SUMMARY OF THE INVENTION
It is an object of the present invention to improve the prior art viscous coupling in that the abrasion particles resulting from the friction between the plates are flushed out of the coupling housing and at the same time to cool the viscous fluid when high loads are applied.
Pursuant to this object, and others which will become apparent hereafter, one aspect of the present invention resides in providing the viscous coupling with a drainage channel which, for pressurizing purposes, may be closed via a shut-off valve and with a supply channel leading to a storage container, and with a flushing pump and that while being in a pressure-free condition, the interior of the viscous coupling is at least temporarily connected to the flushing pump.
With the help of the flushing pump it is possible to flush the interior of the viscous coupling through the supply and drainage channels. To ensure that the functioning of the viscous coupling is not adversely affected, flushing takes place only in the pressure-free condition of the viscous coupling, which is the reason why the supply channel may be closed by a shut-off valve.
In a further embodiment of the invention, the fluid for flushing the viscous coupling is supplied from the flushing pump into the piston cylinder unit whose piston shuts off the fluid supply during pressurization. This measure permits the supply channel of the pump to be closed automatically through the piston travel when pressure is applied, as a result of which functioning of the viscous coupling is maintained.
In a preferred embodiment, the flushing pump is designed as a vane or hose pump.
According to a further embodiment, the viscous coupling is combined with the flushing pump to form an assembly, with the drive for the flushing pump being derived from the speed differential between the coupling plates of the input and output ends and with the assembly being enclosed by a storage container. By combining the viscous coupling with the flushing pump, the entire assembly is arranged within the storage container, thereby permitting multiple applications in the drive assembly of a motor vehicle.
For cooling the viscous fluid, in a further embodiment, the fluid flow passes through a flow cooler.
The fluid level in the storage container should preferably be kept below the passage apertures for the input and output ends of the assembly consisting of the viscous coupling and flushing pump. In this way it is ensured that the viscous coupling is easy to regulate and control and there is no need for stringent requirements as far as sealing the coupling housing relative to the coupling hub is concerned.
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 drawings.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a diagrammatic view of the principle of the invention;
FIG. 2 shows the principle according to FIG. 1 including an additional flow cooler;
FIG. 3 shows a possible design of the piston/cylinder unit including a supply channel;
FIG. 4 shows a possible design of the flushing pump in the form of a hose pump;
FIG. 5 illustrates the viscous coupling in accordance with the invention, in the case of which the flushing pump is integrated into the viscous coupling; and
FIG. 6 is a further embodiment of the viscous coupling having an integrated flushing pump.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
FIGS. 1 and 2 illustrate the principle of the invention by showing a sketch of the fluid circuit. A viscous coupling 1 is connected to a flushing pump 3 via a piston/cylinder unit 2. A supply pipe 4 of the flushing pump 3 is connected to a storage container 5 from which the viscous fluid is sucked. Through the flushing pump 3 and via the piston/cylinder unit 2 as well as the connecting pipe 6, 7, the viscous fluid reaches the interior of the viscous coupling 1. Any excess pressure in the viscous coupling 1 is prevented by a further connecting pipeline 8, 9 between the viscous coupling 1 and the storage container 5, with a shut-off valve 10 having a closing function. The connecting pipeline 8, 9 always has to be closed when torque is to be transmitted by the viscous coupling 1 and when the internal pressure is increased by the piston/cylinder unit 2. At the same time, when pressure is applied to the viscous coupling 1, the fluid supply to the flushing pump 3 is blocked by the piston/cylinder unit so that functioning of the viscous coupling 1 is fully ensured.
In FIG. 2, a flow cooler 11 is provided between the flushing pump 3 and the piston/cylinder unit 2 for the purpose of cooling the viscous fluid.
FIG. 3 shows an embodiment of the piston/cylinder unit 2. The seal between the interior of the viscous coupling 1 and the piston/cylinder unit 2 consists of a cup-shaped sleeve 12. Axial bores 14 connect the annular space 13 to the piston face 15 at the pressure end. The cup-shaped sleeve 12 comprises a bottom part and a sleeve edge 16. A spring plate 18 is arranged between the outer bottom part 17 of the sleeve 12 and the piston face 15 at the pressure end. A spring 19, one end of which is supported on the bottom face 20 of the cylindrical space 21 and the other end of which is supported on the internal bottom 22 of the sleeve 12, ensures contact between the sleeve 12 and the spring plate 18. At the same time, the spring 19 serves to return the piston 23 into its starting position where it establishes contact with the stop ring 24. The spring plate 18 acts on the outer edge of the sleeve 12. When the load on the piston is reduced in the direction of arrow A, the sealing lips, i.e., the reduced sleeve edge 16, are pressed radially inwardly with the assistance of the spring plate 18 and the resulting vacuum so that the sleeve 12 loses its sealing function, with fluid being able to flow from the annular space 13 via the axial bore 14 between the bore wall 25 and the sleeve edge 16, thereby contributing to an exchange of fluid with the cylindrical space 21. This means that the piston 23 is able to return into its basic position abruptly and without being hindered. A supply bore 26 permits the connection of the flushing pump for the viscous coupling 1.
When the piston 23 is pressurized in the direction of arrow A, the supply bore 26 is closed by the sleeve edge 16 and the piston 23, thereby interrupting the fluid circuit of the flushing pump 3 and permitting the viscous coupling 1 to maintain its full function.
FIG. 4 is a diagrammatic illustration of the design of a hose pump. The hose pump 27 substantially consists of an annular housing 28 and a central part 29 rotatably supported therein as well as a hose 30 guided therein. The housing 28 and the central part 29 are each associated with a set of plates of the viscous coupling 1. The rotating central part 29, at its radial ends, comprises a spherical thickened portion 31 dimensioned so that that the hose 30 in the annular housing 28 is compressed and forms a transporting space 32. When a speed differential occurs between the set of plates, the hose pump 27 pumps the viscous fluid from an entry aperture 33 to an exit aperture 34, with the pumping direction being determined by the relative direction of rotation. The hose pump 27 operates in a relatively wear-free manner and is insensitive to abrasion particles in the viscous fluid.
FIG. 5 shows a first embodiment of the invention comprising a viscous coupling 1 and an integrated flushing pump 3. The entire assembly is surrounded by a storage container 5 which is totally enclosed and which comprises two rotation passages 35 for the input shaft 36 and the output shaft 37. The input shaft 36, with the internal teeth of a connecting flange 38, engages the outer teeth of the first set of plates and drives the viscous coupling 1. At the same time, the first set of plates is connected to the housing 28 of the flushing pump 3. The second set of plates of the viscous coupling 1 is associated with the output end and is connected to the central part 29 of the flushing pump 3 and to the output shaft 37. Pressurization of the viscous coupling 1 in the direction of arrow A is effected via a piston/cylinder unit 2 arranged in the rotation aperture 35 at the output end and in the output shaft 37. The connecting pipeline between the viscous coupling 1 and the flushing pump 3, and the shut-off valve 10 are not illustrated in this figure. The storage container 5 surrounding the assembly comprises a fluid level 39 which is positioned below the two rotation apertures 35, so that there is no need for any special seals. At the lowest point of the non-rotatingly arranged storage container 5 there is provided a deposit bag 40 in which abrasion particles of the set of plates may collect. The ventilation bore 41 ensures pressure compensation if the assembly heats up. Because the ventilation nozzle 42 is designed like a smell excluding trap used for sanitary installations, the ventilation nozzle 42, together with the fluid level, may be regarded as a seal against the outside air so that it is not possible for external dirt to penetrate into the storage container 5. The flushing pump 3 sucks the fluid from the fluid level 39 and pumps it into the viscous coupling 1 via the supply bore (not illustrated). The shut-off valve 10 with its connecting pipelines 8, 9 leading to the viscous coupling 1 is not illustrated, either.
FIG. 6 shows the design of the viscous coupling 1 having a flushing pump 3. The viscous coupling 1 comprises a coupling housing 43 having a cylindrical casing whose inner face is provided with axially extending, circumferentially distributed teeth. A coupling hub 44 is rotatably supported in the coupling housing 42 so as to extent concentrically thereto. For this purpose, the coupling hub 44, with its outer face 45, is accommodated in corresponding bores in the coupling housing 43. On its outer face 45, the coupling hub 44 comprises a set of circumferentially distributed teeth extending in accordance with the axial length of the coupling housing 43. Plates 46, 47 are associated with the coupling housing 43 and the coupling hub 44, with the plates 46, via outer teeth, being non-rotatingly accommodated in the housing 43, whereas the plates 47, via a toothed bore, are non-rotatingly arranged to the outer circumference of the coupling hub 44. One end of the coupling housing 43 is closed by a housing cover 48 which is sealed relative to the inner wall of the housing 43, and is held in position by a securing ring 49. Furthermore, the housing 43 is sealed via seals 50 relative to the outer face 45 of the coupling hub 44.
The part of the interior 41 of the housing 43 not occupied by the coupling plates 46 and 47 is filled with a viscous fluid. If the housing 43 moves relative to the coupling hub 44, the fluid shears, and with an increasing relative speed, an increasing torque is built up. The torque, additionally, depends on the viscous fluid pressure prevailing in the housing interior. The housing 43 may, for example, be connected to an input end whereas the coupling hub 44 serves as the output end.
The coupling hub 44 is partially hollow and comprises a bore 52. At its end, there is provided a separating wall which represents the bottom 53 of the cylindrical space 54 formed by the bore. A piston 55 is movably supported in the cylindrical space 54, i.e., at the wall of the bore 52. The piston 55 is sealed relative to the wall of the bore 52 by a primary seal 56 and a secondary seal 57. A spring 58 holds the piston 55 in its position which, in the drawing plane, is displaced to the right, and returns it into its position. The withdrawn position is secured by a stop ring 59. The cylindrical space 54 is connected to the interior 51 of the coupling housing 43 via radially extending, circumferentially distributed bores 60 which are arranged in such a way that they end in approximately the center of the axial extension of the housing 43. Furthermore, the casing of the coupling hub is provided with circumferentially distributed supply bores 61. When the piston 55 is in its starting position, i.e., in the uncoupled position in which practically no torque is transmitted between the coupling housing 53 and the coupling hub 44, the supply bore 61 is not covered, but is in contact with the cylindrical space 54. A rotation passage 62 is arranged on the outer face 45 of the coupling hub 44 so as to be movable relative to the coupling hub 44. The supply bore 61 is connected to the flushing pump 3 via a connecting pipeline 63. If the piston 55 is in the position as illustrated in FIG. 6, the viscous fluid contained in the cylindrical space 54 and in the interior 51 of the coupling housing 43 is under atmospheric pressure. If the piston 55 is moved in the direction of the bottom face 53 of the cylindrical space 54 against the force of the spring 58, the supply bore 61 is closed first so that, if the piston 55 is moved further, pressure builds up in the cylindrical space 54 and in the interior 51 of the housing. The pressure build-up ensures that torque can be transmitted between the coupling housing 43 and the coupling hub 44. If the load is removed from the piston 55, it is returned to its starting position under the influence of the spring 58 until the supply bore 61 again establishes a connection between the cylindrical space 54 and the flushing pump 3.
The piston 55 and the bore 52 form a piston/cylinder unit 2. Because of the open connection between the cylindrical space 54 and the interior 51 of the coupling housing 53, on the one hand, and the cylindrical space 54 and the flushing pump 3 via the supply bore 61, on the other hand, flushing of the viscous coupling 1 is ensured. The connecting pipeline between the flushing pump 3 and the storage container and the connecting pipeline between the viscous coupling 1 and the storage container 5 are schematically illustrated in the drawing.
While the invention has been illustrated and described as embodied in a viscous coupling for a drive assembly, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.
Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention.
What is claimed as new and desired to be protected by letters patent is set forth in the appended claims.
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A viscous coupling having a flushing pump for a drive assembly, in which the abrasion particles occurring as a result of friction between the plates are flushed out of the coupling housing. This is achieved by connecting the viscous coupling to a storage and a supply channel, and the flushing pump is driven as a result of relative movement of the two sets of plates in the viscous coupling and ensures that the viscous fluid flushes the interior of the viscous coupling.
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This application is a provision of Ser. No. 60/013,186 filed Mar. 13, 1996.
This application is a provision of Ser. No. 60/013,186 filed Mar. 13, 1996.
FIELD OF THE INVENTION
The present invention relates to methods and compositions for dissolving coke oven gas ("COG") deposits. More particularly, the invention relates to the use of a synergistic blend of N-methyl-2-pyrrolidinone (NMP) and a second amide, preferably dimethylformamide (DMF), to dissolve COG deposits.
BACKGROUND OF THE INVENTION
Metallurgical coke is produced from coal in a coke oven. The coking process involves the destructive distillation of a complex carbonaceous material. The compounds formed or driven off during the coking process have a wide range of boiling and melting points and solubilities. As a result, selective condensation or crystallization of the compounds with higher boiling points occurs, with consequent plugging of transmission lines, resulting in poor flow and all of the associated difficulties and dangers.
The gas transmission lines carrying coke oven gas can have up to 50% of their cross sectional area blocked by deposition due to (a) the dropping out of organic constituents, or (b) inorganic corrosion products formed by the hydrogen sulfide, cyanide, or thiocyanate contained in the gas acting on the metal piping. Where blast furnace gas is mixed with coke oven gas, iron oxide or other inorganic particles contribute to the reaction that results in corrosion products. Coke oven gas also is usually saturated with naphthalene and other readily sublimable hydrocarbons, such as anthracene and phenanthrene, and droplets of coal tar are almost always carried along throughout the gas system.
Deposits usually form at points of minimum velocity, or at sites of maximum surface to volume ratio, such as burner nozzles and orifice pins. The presence of these deposits limits the gas flow through the mains and can increase the pressure drop across the transmission distribution lines. As a result, proper distribution of the gas can be hindered. The hindrance is especially important for the underfiring system for heating coke ovens or for proper flame temperature control in boilers or reheating furnaces. A particular problem is plugging of the refractory-lined standpipes and goosenecks leading to the horizontal collecting main, which conducts the volatile products to the chemical recovery plant.
A method to prevent plugging of such lines during the refining of coke would be very desirable. One method that has met with success is the introduction of very powerful solvents into the system to dissolve and disperse the deposits. The solvent tends to liquify the deposits, with the liquid being removed from the line through a drip-leg. A most successful product that is used for this purpose contains the solvent N-methyl-2-pyrrolidinone (NMP). Unfortunately, NMP is an expensive solvent. A less expensive solvent system that would effectively prevent such plugging would be very desirable.
SUMMARY OF THE INVENTION
The present invention provides a method of dissolving coke oven gas deposits comprising treating the deposits with a combination of a first amide and a second amide under conditions and at a ratio sufficient to dissolve a first amount of the deposit greater than a second amount of the deposit calculated based upon the proportional individual solvencies of the first amide and the second amide, wherein the first amide comprises N-methyl-2-pyrrolidinone.
DETAILED DESCRIPTION OF THE INVENTION
The solvent of the present invention comprises a mixture of between about 10-90 wt % of NMP and between about 10-90 wt % of a second amide having the following general structure: ##STR1## wherein R 1 is selected from the group consisting of hydrogen, aryl groups, and alkyl groups having between about 1-3 carbon atoms, and wherein R 2 and R 3 independently are selected from the group consisting of hydrogen, aryl groups and alkyl groups having between about 1-2 carbon atoms. Preferably, R 2 and R 3 are the same, and are selected from the group consisting of hydrogen and methyl groups. Suitable second amides include, but are not necessarily limited to dimethylformamide, N,N-dimethylacetamide, N,N-dimethylpropionamide, acetamide, formamide, propionamide, and butyramide. A preferred second amide is dimethylformamide (DMF).
In a preferred embodiment, the amount of N-methyl-2-pyrrolidinone is minimized to the lowest amount possible while still achieving synergism--that is, the dissolution of an amount of the deposit greater than an amount calculated based upon the proportional individual solvencies of the N-methyl-2-pyrrolidinone and the second amide. The amount of the less expensive second amide preferably is maximized in order to minimize cost.
A preferred formulation includes between about 1-10 wt % of a dispersant, preferably Hypermer SC™, a nonionic surfactant mixture available from ICI, Wilmington, Del., and between about 1-70 wt % of a supplemental solvent, preferably a solvent that is less expensive than the active NMP and/or second amide. Suitable supplemental solvents include, but are not necessarily limited to, heavy aromatic naphtha and mixtures of alkyl-substituted aromatics. A preferred supplemental solvent is FINA SOLV 150™, available from Fina Oil and Chemical Company.
When a supplemental solvent and/or dispersant is included, the resulting mixture should contain between about 15-35% of NMP, between about 35-55% of a second amide, and between about 5-50% of the supplemental solvent. In a preferred embodiment, the mixture comprises: about 25 wt % N-methyl-2-pyrrolidinone; about 45% dimethylformamide; about 26% FINA SOLV 150™ and about 4% of Hypermer SC™. NMP, other amide solvents, heavy aromatic naphtha, mixtures of alkyl-substituted aromatics, and nonionic surfactants may be obtained from a number of commercial sources.
In order to use the present invention, the mixture should be injected into the gas flow from coke ovens, preferably by aspiration or atomization, into: plugged or partially plugged gas flow lines; gas transfer lines where gas is used as fuel; low pressure compressors (boosters and exhausters); and/or, various interconnecting piping where the gas is being transported to other locations in the plant for processing. The mixture also can be aspirated into the inlet of a heat exchanger (frequently called a pre-heater) which is just upstream of the underfiring main.
The invention will be better understood with reference to the following examples.
EXAMPLE 1
The relative solvency of the solvent system was measured by dissolving 1.00 g (W 2 ) of a pulverized deposit from the burning of West Virginia and Western Pennsylvania bituminous coal, weighed to 0.01 g, into a 2 oz bottle followed by 9.00 g of solvent. The bottle was capped and shaken for an appropriate amount of time (at least overnight, with some samples being shaken for 31/2 days) on a wrist action shaker. A Millipore filter assembly was readied (using Whatman #40 or #1 paper or, if filtration was too slow, a higher porosity paper) and the equilibrated mixture was poured onto the filter pad while vacuum was applied. After most of the supernatant was passed through, the vacuum was released and a 100 μl sample of the filtrate was transferred to a 100 ml volumetric flask using a Drummond type pipette. The sample was diluted to 100 ml using NMP. Sometimes, further dilution was necessary in order to obtain an absorbance reading of 0.1-0.6 at 425 nm. For purposes of calculation, all absorbances were normalized to correspond to a dilution factor of 10,000. Thereafter, using a standard curve (prepared using either NMP or Candidate A from Example III), the % color bodies dissolved (solvency) was extrapolated.
TABLE I______________________________________ RELATIVE SOLUBILITY.sup.1 OFSOLVENT SOLUTE IN SOLVENT______________________________________NMP 28.6%.sup.2DMF 27.6%NMP/DMF = 50/50 34.9%NMP/DMF = 25/75 31.0%______________________________________ .sup.1 NMP standard curve used. .sup.2 Because of filtration problems, a reading of 20.7% (which is believed to be low), was substituted with previous number that was obtained without the filtration problem.
The table shows the relative solvency of four solvent systems at a solids loading of 43%. Unexpectedly, the combination of either 50/50 or 25/75 NMP/DMF had a higher relative solubility than NMP, alone. The combination of NMP and DMF therefore appears to be synergistic.
EXAMPLE 2
The procedure described in Example 1 was repeated using 50% loading (5 g of COG deposit in 5 g of solvent) in each sample. The results are shown in Table II:
TABLE II______________________________________ SOLUTE IN SOLVENT SOLUTE IN SOLVENT (WT %) (WT %) DUPLICATESOLVENT FIRST ANALYSIS ANALYSIS______________________________________NMP 44.0 42.5DMF 33.3 35.0NMP/DMF = 50/50 46.6 41.7NMP/DMF = 25/75 43.8 43.2______________________________________
The data in Table II is consistent with that in Table I, although the solubilities are higher. The reason for the higher solubility is that the solids loading was higher (50% as opposed to 43%). The relative solvencies are the same.
The NMP/DMF combinations unexpectedly have better relative solvency than the calculated average solvency if no synergism is assumed. Therefore, the combination of NMP/DMF has a synergistic effect; i.e., the combination is unexpectedly superior to either NMP or DMF, individually.
EXAMPLE III
1.0 g (W 1 ) each of COG deposits from the burning of Pennsylvania coal (sample 1) and Mexican bituminous coal (sample 2) was added to a 1/2 oz bottle followed by 4.0 g of solvent candidate. The bottle was placed in an oven at 60° C. (140° F.) for 3 hours. Twice during this three hour period, at 1 and 2 hours, the bottles were removed from the oven and shaken on a wrist-action shaker for 10 minutes, then returned to the oven. A filtration flask and funnel were heated in the oven at 60° C. (140° F.) for 1 hour prior to removing the samples.
After the 3 hour period elapsed, the samples and the filtration equipment were removed from the oven, and the samples rapidly were filtered by vacuum. The residue was washed with 10 ml of acetone and then dried in a vacuum oven for 2 hours at 100° C. (212° F.). After cooling, to room temperature, the residue was weighed (W 2 ). The amount of deposit dissolved was calculated as follows: ##EQU1##
The solvent candidates were the following:
______________________________________CANDIDATE A CANDIDATE B______________________________________70% NMP 45% DMF26% Fina Solv-150 25% NMP 4% Hypermer SC ™ 26% Fina Solv-150 4% Hypermer SC ™______________________________________
The results are shown in Table III:
TABLE III______________________________________ % DEPOSIT % DEPOSIT DISSOLVED.sup.1 DISSOLVEDSAMPLE CANDIDATE A CANDIDATE B______________________________________1 16.1%.sup.2 24.07%.sup.22 32.8%.sup.2 36.1%.sup.2______________________________________ ##STR2## .sup.2 Average of 3 replicates.
Again, the formula containing the NMP/DMF combination unexpectedly performed better than the formula containing the NMP, alone. Therefore, the combination of NMP/DMF has a synergistic effect; i.e., the combination unexpectedly dissolves an amount of the deposit greater than the amount that would be calculated based upon the proportional individual solvencies of the NMP and DMF. A similar synergistic effect would be expected using other second amide solvents.
Persons of ordinary skill in the art will appreciate that many modifications may be made to the embodiments described herein without departing from the spirit of the present invention. Accordingly, the embodiments described herein are illustrative only and are not intended to limit the scope of the present invention.
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The present invention provides a method of dissolving coke oven gas deposits comprising treating the deposits with a combination of a first amide and a second amide under conditions and at a ratio sufficient to dissolve a first amount of the deposit greater than a second amount of the deposit calculated based upon the proportional individual solvencies of the first amide and the second amide, wherein the first amide comprises N-methyl-2-pyrrolidinone.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation application of application Ser. No. 09/824,961 filed on Apr. 3, 2001 and entitled “Two Window Optical Scanner”, which is now U.S. Pat. No. 6,631,845.
FIELD OF THE INVENTION
The present invention relates to optical scanners and particularly to a scanner with at least two windows for scanning objects from different angles.
BACKGROUND OF THE INVENTION
Slot scanners are often used to read and decode bar codes which are disposed on various items. An example of a slot scanner is shown in U.S. Pat. No. 5,717,195, incorporated herein by reference. Two-window slot scanners essentially have a horizontal window and a vertical or generally vertical (referred to as “vertical” hereinafter) window on two surfaces of a generally L-shaped housing. Projecting generally upward out of the horizontal window is a light beam that creates a first set of scan lines while projecting generally horizontally out of the vertical window is a light beam that creates a second set of scan lines. When the scanner is in use, an operator (such as a person working at a supermarket checkout counter) moves an object with a bar code over the horizontal window and past the vertical window. If the bar code is located on the bottom of the object, the bar code reflects the light beam projecting out of the horizontal window. If the bar code is located on the side of the object facing the vertical window, the bar code reflects the light beam projecting out of the vertical window.
Attempts have been made to extend the reading ability of scanners beyond the bottom and one side of an object. One way to accomplish this, for example, is to have a light beam projecting out of the horizontal window at an angle, so that a bar code on some other sides of an object not facing the vertical window can be read. A light beam projecting out from near the top of the vertical window, but at a downward angle, may provide some ability to read a bar code located on the top of an object.
Heretofore, two-window scanners have used beam splitters to split a light beam from a single light source, such as a laser, into two beams. The two beams are directed at different sides of a spinning polygon mirror, which reflects the two beams toward arrays of stationary mirrors. A typical polygon mirror used in this fashion is mounted directly on a motor shaft and has three or four reflecting facets. The arrays of stationary mirrors provide paths for the two beams to form two scan patterns.
Use of a single light source with a beam splitter has several disadvantages. One disadvantage is that a single light source, such as a laser, must be powerful enough to provide two light beams of adequate intensity and therefore must operate at a higher power, which results in a shorter expected operating life. Another disadvantage is that use of a single light source with a beam splitter may be more costly to manufacture than use of two light sources with no beam splitter. This is because a system using beam splitters usually needs additional mirrors and alignment adjustments that actually are more expensive than having two light sources. Yet another disadvantage of using a single light source is that once that light source fails, the scanner becomes non-operational until the light source is replaced.
SUMMARY AND OBJECTS OF THE INVENTION
The present invention relates to a two-window scanner having a plurality of light sources. The scanner has a housing with a horizontal window and a vertical window. Each window has associated with it a light source and a polygon mirror rotated by a motor. Preferably, each window also has a separate collection system for detecting the reflection of the light beam off a bar code. The collection systems send electrical signals to a decoder, which generates a digital signal that corresponds to the bar code. Preferably, the decoder is capable of reading a bar code even if part of the bar code is scanned by one of the windows and another part of the bar code is scanned by the other window.
It is an object of the present invention to provide a two-window optical scanner having two light sources.
It is another object of the present invention to provide a two-window optical scanner with a longer operational life expectancy than previously available.
It is another object of the present invention to provide a two-window optical scanner that is capable of reading bar codes when a light source or other component malfunctions.
It is another object of the present invention to provide a two-window optical scanner that distributes heat within its housing to avoid hot spots near heat-sensitive components.
It is another object of the present invention to provide a two-window optical scanner that utilizes fewer stationary mirrors.
Another object of the present invention is a slot scanner which uses two rotating polygons, each of which is operated by its own motor.
A further object is a slot scanner which uses two lasers, one laser directed at a polygon that scans out of the vertical window, and the other laser aimed at the other polygon and scanned out of the horizontal window.
The polygon that scans the horizontal window is preferably mounted on a motor with its axis of rotation oriented vertically. The axis of rotation of the motor and polygon that scan out of the vertical window is oriented horizontally. Both polygons have four reflective sides, and preferably the sides are tilted differently with respect to the axis of rotation on the two polygons.
The two lasers may be focused differently and/or may operate at different laser powers.
As mentioned above, the scan pattern that is projected out of the horizontal window is preferably generated by the polygon that rotates about a vertical axis. This polygon is located below the horizontal window at the end of the window that is closest to the vertical window.
The polygon scans a laser beam produced by one of the lasers across an array of mirrors located around the periphery of the horizontal window. Most of these mirrors direct the scanned beam downward, away from the window towards a large mirror on the bottom of the housing. The scanned laser lines reflected off this bottom mirror pass upwards through the horizontal window where they will strike a package passing over the window.
The mirrors in the array are preferably oriented such that they produce scan lines in all the orientations needed to read a symbol passed over the window, no matter how the symbol is oriented. The symbol doesn't have to be on the bottom of the package, because the scan lines don't shoot straight up. They emerge from the window at an angle, so they can also shine on the sides of a package moving across the window. There are lines that project on the front of a package (the side in the direction of travel), on the back of the package (opposite the front) and on the end of the package opposite the vertical window.
Some scan lines reflect off one mirror in the array to another mirror in the array and then out the window without reflecting off the large bottom mirror. This enables projection of some scan lines in different directions that can otherwise be obtained.
The use of second motor/polygon allows one to use a much simpler mirror array for the scan pattern projected from the vertical window than is possible with single polygon scanners. Preferably the design uses only four mirrors in this array. Unlike all other two-window scanners, the scan lines radiating from this second polygon (with a horizontal axis of rotation) are reflected off only a single mirror in the array passing out of the window. This makes the mirror array less expensive and also provides a stronger signal to the photodetector that senses the laser light reflected off symbols that are scanned by the vertical window. Eliminating a second mirror in the paths of the outgoing laser beams eliminates half of the losses that are due to the fact that the mirrors only reflect about 90 percent of the laser light.
Although the polygon can be mounted above the four mirrors in the array, it is understood that the scan pattern can also be generated by inverting the arrangement shown so that the polygon is below the mirror array. This inverted arrangement may enable one to separate the left and right pairs of mirrors at the center line which might open up space for two or three more mirrors that can be oriented to direct scan lines down towards the top of low objects passing over the horizontal window. Doing this, one can still retain only a single reflection of the scanned beam off of the array mirrors.
It should be noted that the array mirrors preferably do not project scan lines directly out of the window. The two mirrors on the right are preferably tilted so that the pattern they create projects towards the center line of the scanner as they leave the mirrors. Lines from the two mirrors on the left project the other way so that the lines cross in the space above the horizontal window. This allows the vertical window to read symbols not only on a side of a package parallel to the window, but also on the sides that are rotated up to around 90 degrees, around a vertical axis, with respect to the plane of the vertical window. Thus, both the horizontal and vertical windows have the ability to scan symbols on the front of a package (the side in the direction of travel of the package over the scanner) and on the back of a package. This overlapping capability assures aggressive scanning performance.
Locating the polygon that scans out the vertical window close to the vertical mirror array results in a scan pattern that grows much faster than the patterns created by single polygon scanners, which locate their polygon down low, far from the vertical pattern mirrors. In a preferred embodiment, the rapidly growing scan pattern soon becomes much higher than the window, allowing the scanner to reach higher up the sides of packages than other scanners can.
The vertical and horizontal scanning systems preferably have independent retro-reflective collection systems. The horizontal scanner uses a collection mirror located under the edge of the horizontal window furthest from the vertical window to direct light towards a photodiode mounted near the edge of the P.C. board under the motor that scans the horizontal window. The vertical scanning systems uses a lens to concentrate light onto a second photodiode mounted on the same circuit board but back under the vertical scanning mechanism. This allows the unit to share a common circuit board for both systems, which reduces manufacturing costs
Each photodiode is preferably connected to its own amplifiers and digitizer. The outputs of the two digitizers both go to a decoder that is preferably designed to accept two digitized signals simultaneously.
This scanner will be used primarily to decode UPC, EAN or JAN. These symbologies can be decoded even when no signal scan line covers the whole symbol. Depending on the decode algorithm being used, symbols can be correctly decoded even if they have to be reconstructed from information obtained from up to four different scan lines. The scanner needs to work even if part of a symbol is scanned by one window and another part of the symbol is scanned by the other window. To do this, the decoder will need access to digitized data from both scan windows.
A preferred embodiment for this decoder will use two identical hardware circuits (preferably ASICs). Each circuit will monitor the digitized data arriving from one of the scanning windows. The circuits will recognize likely bar code data, or fragments of bar code data, and, using DMA circuitry, place the bar code data in memory where it can be further examined by a microprocessor. The microprocessor will discard unusable symbol fragments and assemble usable fragments into complete symbols that pass a variety of safety checks to make sure no mistake has been made. When this happens, the scanner will beep and transmit the decoded symbol to the host computer.
Notice that it is unnecessary for the decode microprocessor to have any information about which scan window a symbol fragment was scanned by. It will work if all digitized data is received from a single window, or if fragments are received from both windows.
The decoder will be preferably located on the same circuit board as the photodiodes, amplifiers, digitizers, laser power supplies, motor speed regulators, etc. This avoids the expense and unreliability associated with interconnecting multiple circuit boards.
The circuit board can preferably be located near the bottom of the scanner housing below the vertical window. This allows it to be removed easily for service by removing a cover on the bottom of the housing. Interface connectors can be mounted directly on the edge of the board and are accessible from the back of the scanner housing.
The lifetime of today's laser diodes is very dependent on temperature and optical output power. To assure that the two lasers are at least as reliable as competitors' single laser system, the lasers in the present invention are preferably operated at low output power and are kept cool.
The scanners in the prior art use beam splitters to divide the single laser beam into two beams. Each of these beams has half the optical power of the original single beam. However, each of the two half power beams must have enough power to achieve desired scanner performance. Therefore, the original beam, before being split, has to have twice as much power as is needed for desired scanner operation.
In the present invention having a two-laser system, each laser needs to have only enough power for desired operation, so the laser can operate at one half of the output power of the laser in the prior art scanners, reducing laser output power by half which increases laser life significantly.
The scanner of the present invention is also preferably designed to keep the lasers cooler than other similar scanners. The lasers are preferably located low in the housing, below warm air that floats to the top of the housing. The lasers are preferably located close to the polygons which circulate air around the laser heat sinks. Measurements show that these two things lower laser temperature several degrees below what is achieved with other designs. Laser life is heavily temperature dependent, so this significantly increases their lifetimes.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a two-window scanner of the present invention.
FIG. 2 is a side view of a two-window scanner of the FIG. 1 and a horizontal scan pattern.
FIG. 3 is a top view of the optical layout of a light beam associated with the horizontal window of the scanner of FIG. 1 .
FIG. 4 is a head-on view of the optical layout of a light beam associated with the vertical window of the scanner of FIG. 1 and a vertical scan pattern.
FIG. 5 is a representation of a docking well used to interface a two-window scanner and a hand-held scanner.
DETAILED DESCRIPTION OF THE INVENTION
With reference to FIG. 1 , a two-window optical scanner 100 , having a horizontal window 40 and a vertical window 80 , is shown. In a preferred embodiment shown in FIG. 2 , housing 10 is partially under surface 15 , which can be, for example, a supermarket check-out counter. Light source 22 , preferably a laser, generates a light beam that is reflected off spherical reflector/collector 30 and onto rotating polygon mirror 32 . In a preferred embodiment, rotating polygon mirror 32 has four reflecting facets, rotates around a vertical axis, and is driven by motor 33 . Referring to FIG. 3 , the facets of rotating polygon mirror 32 reflect the incoming light beam toward an array of mirrors H 1 -H 8 located along the periphery of horizontal window 40 . Most, but not all, of the light reflected off of array of mirrors H 1 -H 8 in this preferred embodiment is then reflected off bottom mirror H 9 and out horizontal window 40 (some of the light is reflected off mirror H 1 to mirror H 2 and out horizontal window 40 while some light is reflected off mirror H 8 to mirror H 7 and out horizontal window 40 , for example).
FIG. 2 shows the horizontal scan pattern 50 for the configuration of mirrors disclosed, and scan lines corresponding to combinations of mirrors. A bar code on an object situated in horizontal scan pattern 50 reflects light back through horizontal window 40 and off at least some of mirrors H 1 -H 9 to rotating polygon mirror 32 and spherical reflector/collector 30 . This light reflects off spherical reflector/collector 30 and onto collection assembly 23 , which comprises lens 25 , fold mirror 26 , filter 27 , and photodiode 28 .
Since the light leaving horizontal window 40 approaches horizontal scan pattern 50 at different angles, a bar code being scanned need not be on the bottom of an object—it could very well be on the front or back or a side of the object. For example, it may be easier for light beams not reflecting off of bottom mirror H 9 to read bar codes on the front or back of an object (though this does not exclude the possibility that light beams reflecting off bottom mirror H 9 will read such bar codes). Also, since the scan lines in horizontal scan pattern 50 are at various angles, any orientation of the bar code can be scanned.
Light source 62 , preferably a laser, generates a light beam that shines on rotating polygon mirror 72 . In a preferred embodiment, rotating polygon mirror 72 has four reflecting facets, rotates around a horizontal axis, and is driven by motor 73 . Referring to FIG. 4 , the facets of rotating polygon mirror 72 reflect the incoming light beam toward an array of mirrors V 1 -V 4 located along the periphery of vertical window 80 and out vertical window 80 .
FIG. 4 shows the vertical scan pattern 90 for the configuration of mirrors disclosed. A bar code on an object situated in vertical scan pattern 90 reflects light back through vertical window 80 and off at least some of mirrors V 1 -V 4 to rotating polygon mirror 72 , which then reflects it toward collector lens 70 and photodiode 68 .
Since the light leaving vertical window 80 approaches vertical scan pattern 90 at different angles, a bar code being scanned need not be on the side of the object facing vertical window 80 —it could very well be on the front or back of the object, by way of example only. Also, since the scan lines in vertical scan pattern 90 are at various angles, any orientation of the bar code can be scanned.
Various features of the embodiment described above are used to further improve performance, drive down cost, etc. For example, in a preferred embodiment the facets of rotating polygon mirror 32 may be tilted at different angles with respect to the axis of rotation; similarly, the facets of rotating polygon mirror 72 may also be tilted at different angles with respect to their axis of rotation. Light source 22 and light source 62 may be focused differently and/or may operate at different power. In the preferred embodiment shown, for example, some of the light generated by light source 22 is reflected off more surfaces than the light generated by light source 62 , and so it may be advantageous for light source 22 to operate at a higher power.
In an alternative preferred embodiment, the positions of rotating polygon mirror 72 and array of mirrors V 1 -V 4 is inverted so that rotating polygon mirror 72 is below array of mirrors V 1 -V 4 . Such an arrangement enables mirrors V 1 , V 2 to be shifted to the left and mirrors V 3 , V 4 to be shifted to the right so that additional mirrors may be placed in between. These additional mirrors can be oriented so that they direct scan lines down toward the top of low objects being passed over horizontal window 40 .
Locating rotating polygon mirror 72 close to array of mirrors V 1 -V 4 results in a scan pattern that grows faster than patterns created by single polygon mirror scanners, which typically locate their rotating polygon mirrors lower in the housing, far from a vertical array of mirrors. In a preferred embodiment of the present invention, a rapidly growing vertical scan pattern 90 grows higher than vertical window 80 , allowing two-window optical scanner 100 to read bar codes located higher up on the sides of objects being passed through.
In a preferred embodiment, the vertical and horizontal scanning systems disclosed have independent retro-reflective collection systems. The horizontal component of two-window optical scanner 100 uses spherical reflector/collector 30 to direct light toward photodiode 28 . The vertical component of two-window optical scanner 100 uses collector lens 70 to focus light onto photodiode 68 . In a preferred embodiment, light source 22 , collection assembly 23 , light source 62 , and photodiode 68 are all mounted on a single printed circuit board 110 near the bottom of housing 10 , reducing manufacturing costs and allowing easy removal.
In a preferred embodiment, photodiode 28 and photodiode 68 each has its own amplifier and digitizer, and the outputs of the two digitizers go to a decoder designed to accept two digitized signals simultaneously. In a preferred embodiment the decoder is also mounted on printed circuit board 110 , and connects to a host computer by way of connectors 120 .
Two-window optical scanner 100 may be used to read and decode a large variety of bar code symbols. In a preferred embodiment, bar code symbols conforming to at least the UPC, EAN, or JAN standards are read and decoded. These symbologies can be decoded even when no scan line covers the whole symbol. Depending on the decode algorithm being used, symbols can be accurately decoded even if they need to be reconstructed from information obtained from up to four scan lines. Preferably, the decoder used to decode signals from photodiodes 28 , 68 uses the information from both photodiodes so that if part of bar code is scanned through horizontal window 40 and another part of the bar code is scanned through vertical window 80 , the bar code can nevertheless be decoded.
In a preferred embodiment, the decoder uses two substantially identical hardware circuits (such as ASICs). Each circuit monitors digitized data arriving from one of the photodiodes. Using DMA or other circuitry, bar code data or fragments of bar code data is recognized and placed in a memory where the information can be further analyzed by a microprocessor. Preferably, the microprocessor discards unusable symbol fragments and assembles usable fragments into complete symbols that pass a variety of safety checks to ensure that the bar code has been read accurately. It would not be necessary for the microprocessor to have information on which scan window was used to scan a bar code or bar code fragment. A beep may indicate that a successful scan has been accomplished, and information related to the decoded bar code symbol may be transmitted to a host computer.
As indicated above, in a preferred embodiment light source 22 and light source 62 are lasers. Since two lasers are used, each one uses less power than a single laser generating two light beams (using a beam splitter) and thus operates cooler and can expect to have a longer operating life. Other methods of extending laser life in a preferred embodiment include: use of heat sinks, low placement of the lasers within housing 10 to avoid warm air that tends to float to the top of housing 10 , and placement of the lasers close to rotating polygon mirrors 32 , 72 that act like fans to circulate air around the lasers and/or their heat sinks. Advantageously, if one of the lasers (or other component, such as a motor by way of example only) does happen to fail, two-window optical scanner 100 can operate using only one window.
In a preferred embodiment, other features of the present invention include a display or other indicator for indicating that only one of the scanning mechanisms is functioning. Additionally, a user may wish to connect a hand-held scanner (by means of a cable, radio, infrared, or other connection means) that does not have its own decoder to two-window optical scanner 100 . Using a trigger such as a switch, the scanning mechanisms within two-window optical scanner 100 may be disconnected from, and the hand-held scanner connected to, the decoding circuitry within housing 10 . Similarly, light sources 22 , 62 may be powered off when the hand-held scanner is connected or being used. Additionally, a docking well 500 in or on two-window optical scanner 100 that is receptive of a hand-held scanner and has the functions shown in FIG. 5 may be used to interface two-window optical scanner 100 and the hand-held scanner. Signal 510 from a hand-held scanner is converted to data via input processor 520 for storage in data well 550 . The data in data well 550 is retrieved by processor 560 and sent as signal 570 to two-window optical scanner 100 . In an alternative preferred embodiment, two-window optical scanner 100 may comprise, or be attached to, a base station, such as the base stations disclosed in U.S. Pat. No. 5,668,803, incorporated herein by reference, for use with a cordless scanner.
The present invention has been illustrated and described with respect to specific embodiments thereof. It is to be understood, however, that the above-described embodiments are merely illustrative of the principles of the invention and are not intended to be exclusive embodiments.
Alternative embodiments capturing variations in the enumerated embodiments disclosed herein can be implemented to achieve the benefits of the present invention.
It should further be understood that the foregoing and many various modifications, omissions and additions may be devised by one skilled in the art without departing from the spirit and scope of the invention.
It is therefore intended that the present invention is not limited to the disclosed embodiments but should be defined in accordance with the claims which follow.
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The invention relates to a scanning device for reading bar code symbols, wherein the scanning device comprises a housing having a substantially horizontal surface and a substantially vertical surface. A motor rotates a polygon mirror, which reflects a light beam from a light source and redirects it toward a mirror array and out a window in the substantially horizontal window. Another motor rotates another polygon mirror, which reflects a light beam from a second light source and redirects it toward a second mirror array and out a window in the substantially vertical surface. A plurality of sensors detects light reflected back from a bar code and generates a plurality of electrical signals proportional to the intensity of the reflected light.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This is a continuation-in-part of patent application Ser. No. 09/664,271 filed Sep. 18, 2000.
FIELD OF THE INVENTION
[0002] This invention relates to the production of illusionary snow. More particularly, a machine which capable of creating the illusion of snow for theatrical or special effect purposes without the use of refrigeration, and without causing the accumulation of any residual moisture in the area in which it is used.
BACKGROUND OF THE INVENTION
[0003] The world of theater and special effects has prided itself on the ability to create illusions. The masters of this art are continually creating their magic for the entertainment of their patrons. One of the most challenging illusions is that of snow. This presents a distinct difficulty. Limitations based on temperature and accumulation of moisture have always plagued the special effects creators.
[0004] There are many commercially available machines for producing snow. Many of these liquid based snow machines have been able to produce artificial snowflakes. The flakes formed were tight groupings of bubbles that were moist and had a tendency to clump together. This caused difficulty in dissipation. Additionally, there were concerns regarding moisture buildup in the area in which the machine was used. The problems of slippery floors, surfaces, and staining from the product have not been overcome. In an attempt to overcome these problems, people have attempted the use of fans in order to more widely distribute the artificial snow produced by these earlier machines. However, the flakes tend to form agglomerates which are not substantially effected by the auxiliary fans. These auxiliary fans do not overcome the physical difficulty of moisture buildup or the danger, which it presents.
[0005] The current invention overcomes these deficiencies. It provides for the creation of illusionary snow by an apparatus that utilizes a solution, which is commercially available as FG-100 Evaporative Snow (manufactured by Snow Masters, Plantation Fla.) drawn into a turbulent carrier wave of air at the same point at which the flakes are produced. The preciseness of placement of the carrier wave prevents tight clumps from forming, and causes greater separation between the flakes. Once the individualized flakes are carried from the machine, the evaporative process occurs and prevents moisture buildup.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] [0006]FIG. 1 shows a complete illusionary snow machine that incorporates all of the aspects of the invention.
[0007] [0007]FIG. 2 illustrates the pump with connecting hose and the flake generator.
[0008] [0008]FIG. 3 illustrates a front view of the apparatus
[0009] [0009]FIG. 4 illustrates the apparatus in a cut away from the front
[0010] [0010]FIG. 5 illustrates the apparatus in a cut away from the rear
[0011] [0011]FIG. 6 is a foam streamer attachment
[0012] [0012]FIG. 7 illustrates the foam streamer in a cut away
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0013] The illusionary snow solution 2 under pressure is drawn into connecting hose 3 by means of an in-line liquid pump 1 at a rate of 4 ounces per minute. The liquid then continues to a flake generator 7 where it saturates a sock 4 . An impeller 5 contained within flake generator 7 causes flakes to form and to be projected into the air while an integrated carrier fan 6 facilitates the distribution of individual flakes. The flake generator 7 will produce a constant 3000 cubic feet per minute of airflow. This volume of air is forced through sock 4 and holes 8 , which are on the outer surface of flake generator 7 . Pressure of the air coming through sock 4 causes flakes to be formed on the outer surface of said sock 4 . The volume of air produced by impeller 5 that exits flake generator 7 through the holes 8 lift the flakes from the surface of sock 4 . Once the flakes are lifted from sock 4 , they are projected away from the apparatus by means of airflow produced by carrier fan 6 . When the force of air contacts the flakes produced carrier fan 6 there are two physical phenomena that occur. First the flakes are broken into smaller particles. This is a novel part of the current invention. The other commercially available machines have a great tendency to produce larger agglomerates, which in turn lead to excessive moisture buildup in the surrounding area. Second, once the flakes are separated into smaller particles, they are more easily dispersed in the area away from the machine. Once they are in the air in this matter the overall ratio of surface area exposed to air greatly increases. With this increased surface are comes a greater ability to speed the evaporative process. These two factors combine to speed the evaporative process and make it more complete. Another novelty of the current invention lies in the design of carrier fan 6 being lined up with flake generator 7 to lift the flakes and eject them from the apparatus in a manner that is greatly increased then a machine that would not contain both of these features placed together and at a proper distance from one another. This allows the flakes to remain in the air for a longer period of time and thus increases the transit time before they reach the ground. This increased time provides more exposure to air and allows for the completeness of evaporation to occur. The final result is an evaporative artificial snowfall that is truly free from residue of any type. Additionally, the snow produced does not resemble typical artificial snow that is ejected from a carrier hose or other apparatus. The current invention lifts the illusionary snow in a manner that produces a gentle cloud of snow in a wider horizontal area. The individualized flakes provide a cloud of gently falling flakes that is truly more realistic than anything currently available.
[0014] In one embodiment it has been found that one need not place the carrier fan in a centered position behind the flake generator. It has further been discovered that when placing a drum fan outlet below the flake generator and sock, on can produce a greater amount of illusionary snow, without increasing the velocity of the air from the carrier fan. In using a drum fan with the current invention, it has been discovered that a very large volume of illusionary snow can be produced. The volume is such that this embodiment allows the subject invention to be used in large arenas and stadiums. The same velocity of 3000 cubic feet per minute will generate a noticibly increased amount of illusionary snow. This is an important feature because without the need or increased air velocity, there is no increase in any noise created by the apparatus. If the apparatus were to be used indoors eg. in the theater, the amount of noise created would be minimal. Additionally, with the increased efficiency comes the ability of the user to regulate the flow rate of the solution into the apparatus. The solution can have a flow rate between 1-4 ounces per minute and still produce illusionary snow.
[0015] [0015]FIG. 3 illustrates an embodiment with apparatus housed within a case 140 which has a handle 170 on either side to facilitate carrying. A container 150 for holding the solution is placed inside when opening door 145 . The sock 155 as previously described is mounted on the front upper portion of the apparatus. An outlet air exhaust 165 provides air from the carrier fan.
[0016] [0016]FIG. 4 shows the interior of the case 140 in which a drum fan 205 as is comonly known in the art, is used to produce the necessary velocity to project the illusionary snow from the apparatus. There is a plate 185 for holding inlets 175 and 185 through which a remote control means can be connected to operate the apparatus. The circuit board 220 receives electrical power from either electrical inlet 195 or 200 which are secured to case 140 by means of a connecting plate 190 and can be controlled through a suitable controlling means as connected to either connector 175 or 180 .
[0017] [0017]FIG. 5 illustrates the aforementioned elements, and additionally shows placement of the flake generator 160 and the pump 225 .
[0018] The method for producing an illusionary snowfall which employs an evaporative snow solution, is a method comprising the steps of:
[0019] Supplying electricity to the unit and drawing said evaporative snow solution into an apparatus through a hose, which is connected to a pump, directing said solution from said pump to a flake generator, which forms flakes on the outer surface of a sock, said flake generator comprises an impeller which disperses evaporative snowfall away from the apparatus, and a carrier fan which provides added velocity in projecting the illusionary snow from the apparatus.
[0020] In a further embodiment of the subject invention it has been discovered that if one prevents the air from the holes on the outer surface of the flake generator, from reaching the sock, the illusionary snow will be produced in larger from as opposed to individual flakes. FIG. 6 illustrates an attachment which is connected to the outside of the flake generator and prevents the air from the holes on the outside of the flake generator from removing individualzed flake. The air flow from the flake generator that reaches the sock, creates a solid form. In this embodiment, a cylindrical shield 235 prevents air from the holes on the outer surface of the flake generator 245 from reaching the sock. FIG. 7 shows the position of a sock 240 within the cylindrical shield. In this embodiment, the cylindrical shield produces long cylindrical columns of illusionary snow. These long cylindrical columns are carried from the sock that reaches the sock from the flake generator. Once the cylindrical column exits the cylindircal shield, the carrier fan propels it away from the apparatus. One can make the shield in various shapes in order to change the shape of the column.
[0021] While the invention has been described in its preferred form or embodiment with some degree of particularity, it is understood that this description has been given only by way of example and that numerous changes in the details of construction, fabrication, and use, including the combination and arrangement of parts, may be made without departing from the spirit and scope of the invention.
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A Machine and method for producing the illusion of snow is disclosed and described. It produces said product in a manner such that is easier to manufacture, operate, and produce than is currently available.
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CROSS-REFERENCE TO RELATED APPLICATION(S)
This application claims priority under 35 U.S.C. § 119(e) to U.S. Provisional Application Ser. No. 60/431,828, filed on Dec. 9, 2002, which is incorporated herein by reference.
FIELD OF THE INVENTION
This invention relates to a grip, and more particularly, to a grip and/or a firearm with a grip having a hinged pull tab.
BACKGROUND OF THE INVENTION
Modern firearms often require batteries for the operation of various firearm features, such as laser sight lines, lights, laser illuminators, laser target designators, infra-red lights, illuminated sights, and holographic sights. Accordingly, a need exists for a firearm grip having an internal battery storage chamber and/or a firearm grip having a hinged pull tab that removably covers a firearm grip cavity.
SUMMARY OF THE INVENTION
In one embodiment, the present invention is a grip for attachment to a firearm. The grip includes a housing having an internal storage cavity and a pull tab fixedly attached to the housing. The pull tab includes a body and a stopper attached to the body, which removably engages a wall that defines an open end of the internal storage cavity to removably cover the internal storage cavity.
In another embodiment, the present invention is a firearm grip for attachment to a firearm. The firearm grip includes a housing having an internal storage cavity and a pull tab fixedly attached to the housing. The pull tab includes a body; a stopper attached to the body, which removably engages a wall that defines an open end of the internal storage cavity to removably cover the internal storage cavity; a protrusion that extends from the body and removably lockingly engages a wall that defines a notch in the housing; a hinge integrally formed with the body, allowing for pivotal movement of the body; and a flexible handle integrally formed with the body.
In yet another embodiment, the present invention is a firearm grip for attachment to a firearm. The firearm grip includes a housing having at least two elongated cylindrical internal storage cavities and a pull tab fixedly attached to the housing. The pull tab includes a body and a stopper attached to the body for each internal storage cavity, wherein each stopper removably engages a wall that defines an open end of a corresponding one of the internal storage cavities to removably cover the internal storage cavity, and wherein each stopper includes at least one ring about its perimeter, which removably frictionally engages the wall that defines the open end of a corresponding one of the internal cavities to form a water tight seal with the internal cavity to prevent moisture from entering therein. The pull tab also includes a protrusion that extends from the body and removably lockingly engages a wall that defines a notch in the housing; a hinge integrally formed with the body, allowing for pivotal movement of the body; and a flexible handle comprising a first end integrally formed with the body and a free movable second end that resiliently retracts to a position adjacent to a bottom surface of the body when no external force is applied thereto.
In still another embodiment, the present invention is a firearm that includes a firearm grip having a housing with an internal storage cavity. A pull tab is fixedly attached to the housing. The pull tab includes a body; a stopper attached to the body, which removably engages a wall that defines an open end of the internal storage cavity to removably cover the internal storage cavity; a protrusion that extends from the body and removably lockingly engages a wall that defines a notch in the housing; a hinge integrally formed with the body, allowing for pivotal movement of the body; and a flexible handle integrally formed with the body.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a firearm grip according to the present invention;
FIG. 2 is a side view of the firearm grip of FIG. 1 attached to a firearm and having, in an opened position, a hinged pull tab;
FIG. 3 is a longitudinal cross-sectional view of the firearm grip of FIG. 1 with the hinged pull tab omitted for clarity;
FIG. 4 is a bottom view of the firearm grip of FIG. 1 with the hinged pull tab omitted for clarity;
FIG. 5A–5D each show a longitudinal cross-sectional view of the firearm grip of FIG. 1 having batteries in various battery arrangements within a battery storage chamber of the firearm grip;
FIG. 6 is a longitudinal cross-sectional view of the firearm grip of FIG. 1 showing the hinged pull tab mounted therein for supporting batteries that are disposed within a battery storage chamber of the firearm grip;
FIG. 7 is a lateral cross-sectional view of the hinged pull tab of FIG. 6 taken from line 7 — 7 of FIG. 6 ;
FIG. 8 is a bottom view of the hinged pull tab of FIG. 6 ; and
FIG. 9 is a longitudinal cross-sectional view of the hinged pull tab of FIG. 6 taken from line 9 — 9 of FIG. 8 .
DESCRIPTION OF THE INVENTION
As illustrated in FIGS. 1–9 , embodiments of the present invention are directed to a firearm grip having an internal battery storage chamber and/or a firearm grip having a hinged pull tab that removably covers a firearm grip cavity, such as a battery storage chamber.
FIG. 1 shows a firearm grip 10 according to one embodiment of the present invention. FIG. 2 shows the firearm grip 10 attached to a weapon, such as a firearm or gun 12 (for clarity purposes, only a portion of the firearm 12 is shown.) As discussed in detail below, the firearm grip 10 includes a housing 11 having a pull tab 14 attached thereto, which removably covers an internal cavity of the housing 11 , such as an internal battery storage chamber 16 , as shown for example in FIG. 3 .
In the embodiment of FIG. 3 , the battery storage chamber 16 includes two storage cavities 18 . Each cavity 18 , in turn, includes a series of inwardly stepped battery compartments that extend from a lower portion 22 of the firearm grip 10 to an upper portion 24 of the firearm grip 10 .
In the depicted embodiment, each cavity 18 includes a first battery compartment 26 , a second battery compartment 28 , and a third battery compartment 30 . In the embodiment of FIGS. 3 and 4 , each battery compartment 26 , 28 and 30 is substantially cylindrical in shape, with each successive battery compartment 26 , 28 and 30 having a smaller diameter than its adjacent battery compartment when viewed from the lower portion 22 of the firearm grip 10 to the upper portion 24 of the firearm grip 10 .
In another embodiment, although each cavity is generally inwardly stepped from the lower portion 22 to the upper portion 24 of the firearm grip 10 , one or more of the battery compartments may be substantially the same size as an adjacent battery compartment. In addition, in another embodiment, each cavity includes a plurality of battery compartments that are each of substantially the same size.
In one exemplary embodiment, each battery compartment 26 , 28 and 30 also shares a common wall. For example, in the embodiment of FIGS. 3 and 4 , each battery compartment 26 , 28 and 30 is non-concentrically positioned with respect to the remaining battery compartments, such that a side of each battery compartment 26 , 28 and 30 is aligned to form a substantially smooth common wall 32 that extends across the length of each cavity 18 . The smooth wall 32 facilitates insertion of batteries into the battery compartments 26 , 28 and 30 of each cavity 18 .
At least one of the cavities 18 includes a fastener hole 34 , for example at its uppermost end, for receiving a fastener 36 , such as a screw. The fastener 36 extends through the fastener hole 34 enabling the firearm grip 10 to be removably secured to the firearm 12 . A sealing washer 38 is disposed between a head 40 of the fastener 36 and the fastener hole 34 to create a fluid tight seal at the uppermost end of the corresponding cavity 18 , in which the fastener hole 34 is disposed.
Opposite the common wall 32 each battery compartment 26 , 28 and 30 forms a shoulder 26 S, 28 S and 30 S at its upper end for receiving and supporting an upper end of a battery. In embodiments, where the battery compartments 26 , 28 , and 30 are concentric, however, each battery compartment 26 , 28 and 30 forms two shoulders at its upper end for receiving a battery.
FIGS. 5A–5D show examples of how various batteries fit within the battery compartments 26 , 28 and 30 according to exemplary embodiments of the invention. For example, as shown in FIG. 5A–5D , the third battery compartment 30 is formed to securely receive a typical DL-1 type battery 42 . As such, the length and diameter of the third battery compartment 30 are substantially the same as or slightly larger than the length and diameter of the DL-1 type battery 42 , while the uppermost portion of the third battery compartment 30 forms the shoulder 30 S that is smaller than the diameter of the DL-1 type battery 42 to prevent the DL-1 type battery from extending therepast.
As shown in FIG. 5C , the first battery compartment 26 is formed to securely receive a typical 123 Lithium Series battery 44 . As such, the length and diameter of the first battery compartment 26 are substantially the same as or slightly larger than the length and diameter of the 123 Lithium Series battery 44 , while the uppermost portion of the first battery compartment 26 forms the shoulder 26 S that is smaller than the diameter of the 123 Lithium Series battery 44 to prevent the 123 Lithium Series battery 44 from extending therepast.
As shown in FIG. 5A , the first and second battery compartments 26 and 28 are formed to securely receive a typical AA battery 46 . As such, the combined length of the first and second battery compartments 26 and 28 is substantially the same as or slightly larger than the length of the AA battery 46 ; and the diameter of the second battery compartment 28 is substantially the same or slightly larger than the diameter of the AA battery 46 , while the uppermost portion of the second battery compartment 28 forms the shoulder 28 S that is smaller than the diameter of the AA battery 46 to prevent the AA battery 46 from extending therepast.
As shown in FIG. 5D , the second battery compartment 28 is formed to securely receive a typical N type battery 48 . As such, the diameter of the second battery compartment 28 is substantially the same as or slightly larger than the diameter of the N type battery 48 , while the uppermost portion of the second battery compartment 28 forms the shoulder 28 S that is smaller than the diameter of the N type battery 48 to prevent the N type battery 48 from extending therepast.
In any portion of each cavity 18 that does not receive a battery, a spacer 50 may be inserted to reduce movement (i.e., rattling) of the batteries within the cavity 18 . In one embodiment, the spacer 50 is a foam spacer that is laterally compressible to fit within any of the battery compartments 26 , 28 and 30 .
In addition, the pull tab 14 , discussed in more detail below, is attached to the lower portion 22 of the firearm grip 10 to support a lower surface of any battery or spacer that is positioned adjacently thereto. In one embodiment, the pull tab 14 slightly extends into the first battery compartment 26 to press against any battery or spacer that is positioned adjacently thereto. This further reduces rattling of the batteries within each cavity 18 .
FIGS. 5A–5D show exemplary arrangements of batteries combinations that may be received within each cavity 18 of the firearm grip 10 . For example, FIG. 5A shows each cavity 18 storing a DL-1 typebattery 42 and a AA battery 46 , with a spacer 50 disposed above the DL-1 type battery to reduce rattling. FIG. 5B shows each cavity 18 storing a DL-1 type battery 42 with a spacer 50 disposed therebelow to reduce rattling. FIG. 5C shows each cavity 18 storing a DL-1 type battery 42 and a 123 Lithium Series battery 44 , with a spacer 50 disposed therebetween to reduce rattling. FIG. 5D shows each cavity 18 storing a DL-1 type battery 42 and a N type battery 48 , with a spacer 50 disposed below the N type battery 48 to reduce rattling.
Although the battery compartments 26 , 28 and 30 have been described above as capable of receiving and storing some combination of DL-1 type batteries 42 , N type batteries 48 , 123 Lithium series batteries 44 and AA batteries 46 , the battery compartments 26 , 28 and 30 may be formed to receive any appropriate type of battery and/or any appropriate combinations of batteries.
Although the battery compartments 26 , 28 and 30 have been described above as being cylindrical in shape, each battery compartment 26 , 28 and 30 may be formed to any one of a variety of shapes, such as rectangular, square, elliptical, or crescent, among other appropriate shapes. In addition, one or more of the battery compartments 26 , 28 and 30 may have a different shape than the remaining battery compartments 26 , 28 and 30 and/or each battery compartment 26 , 28 and 30 may have a different shape.
Also, although each cavity 18 has been described as having three battery compartments 26 , 28 and 30 , each cavity 18 may have any number of battery compartments, limited only by the desired length of the firearm grip 10 ; and although the battery storage chamber 16 has been described as having two cavities 18 , the battery storage chamber 16 may have any appropriate number of cavities 18 , such as one, three or four, for example.
In one embodiment, the firearm grip 10 is formed from a non-conductive material, such as a hard plastic material, in a molding process. Although, the firearm grip 10 may be formed from any appropriate material, it is desirable that at least the lower and upper portions 22 and 24 of the firearm grip 10 and/or the upper and lower ends of each cavity 18 are either formed from a non-conductive material or insulated so that electrical current does not flow through the batteries when the batteries are stored within each cavity 18 . Although the battery storage chamber 16 has been described above as being used in a firearm grip 10 , the battery storage chamber 16 may be incorporated into any appropriate portable device such as a camera.
The pull tab 14 is attached to the lower portion 22 of the firearm grip 10 . In one embodiment, the pull tab 14 is integrally formed from a flexible material, for example an elastomeric material, such as a rubber material. As shown in FIG. 3 , the housing 11 of the firearm grip 10 includes a slot 52 for receiving the pull tab 14 .
As shown in FIGS. 6 and 9 , the pull tab 14 includes an arm 54 that is fixedly mounted within the slot 52 , such that the pull tab 14 is integral to the firearm grip 10 . The pull tab 14 may be mounted within the slot 52 by any appropriate means such as by use of an epoxy, an adhesive, a mechanical fastener, or heat fusing among other appropriate fastening means.
The arm 54 is connected to an integrally formed hinge 56 that allows for pivotal movement of the pull tab 14 . The pull tab 14 has a body portion 55 that contains one or more stoppers 58 . The pull tab 14 contains one stopper 58 for each cavity 18 in the battery storage compartment 16 of the firearm grip 10 .
For example, in the embodiment of FIG. 6 the battery storage compartment 16 contains two cavities 18 in the battery storage compartment 16 of the firearm grip 10 and the pull tab 14 includes two stoppers 58 . Each stopper 58 fits tightly within a lower opening 60 of its corresponding cavity 18 to frictionally secure each stopper 58 within its corresponding cavity 18 . In one embodiment, the lower opening 60 of each cavity 18 is substantially circular and each stopper 58 is substantially cylindrical.
When secured within its corresponding cavity 18 , each stopper 58 forms a water tight seal with a wall of its corresponding cavity 18 to prevent moisture from entering the cavity 18 . In addition, when secured within its corresponding cavity 18 , each stopper 58 longitudinally supports the batteries and/or spacers that are disposed within its corresponding cavity 18 .
As shown in FIGS. 6–9 , each stopper 58 has at least one circumferential ring 62 , such as a circular ring. Although the depicted embodiment shows each stopper as having two circumferential rings 62 , each stopper 58 may have any appropriate number of circumferential rings 62 . Each circumferential ring 62 assists in frictionally securing the stopper 58 within against a wall of its corresponding cavity 18 and assists in creating a water tight seal between the stopper 58 and its corresponding cavity 18 to prevent moisture from entering the cavity 18 .
In one embodiment, the pull tab 14 includes a protrusion 64 that mates with a notch 66 in the housing 11 of the firearm grip 10 . In the embodiment of FIG. 3 , the notch 66 is part of an opening 68 in the housing 11 of the firearm grip 10 that is disposed below the battery storage chamber 16 . The mating of the protrusion 64 of the pull tab 14 with the notch 66 in the firearm grip 10 provides a locking engagement between the pull tab 14 and the firearm grip 10 and helps secure each stopper 58 within its corresponding cavity 18 .
An integrally formed flexible handle 70 extends from the pull tab 14 . When the handle 70 is pulled in a direction away from the lower portion 22 of the firearm grip 10 , the body 55 of the pull tab 14 rotates about the hinge 56 of the pull tab 14 , causing the protrusion 64 of the pull tab 14 to disengage from the notch 66 of the firearm grip 10 , and causing each stopper 58 to disengage from its corresponding cavity 18 . When the handle 70 is released, the handle 70 resiliently retracts adjacent to the body 55 of the pull tab 14 .
Similarly, when the handle 70 is pushed in a direction towards the lower portion 22 of the firearm grip 10 , the body 55 of the pull tab 14 rotates about the hinge 56 of the pull tab 14 , causing the protrusion 64 of the pull tab 14 to lockingly engage the notch 66 of the firearm grip 10 , and causing each stopper 58 to frictionally engage its corresponding cavity 18 .
In the embodiments of FIGS. 6–9 , each stopper 58 includes a an inner ring 73 and an outer ring 75 separated by a channel 74 . The channel 74 assists in dust and debris collection within the battery storage chamber 16 and allows the outer ring 75 to be easily compressible. An advantage of the outer ring 75 being easily compressible is that it allows the outer ring 75 to be formed to a larger size than the lower opening 60 of its corresponding cavity 18 . Thus, forming a more secure frictional engagement of each stopper 58 with its corresponding cavity 18 .
In the embodiment of FIG. 6 , the pull tab 14 is mounted within to the firearm grip 10 in an opening 68 in the housing 11 of the firearm grip 10 that is disposed below the battery storage chamber 16 , such that when each stopper 58 is frictionally engaged with its corresponding cavity 18 and when the protrusion 64 of the pull tab 14 is lockingly engaged the notch 66 of the firearm grip 10 , the pull tab 14 is disposed completely within the opening 68 with the handle 70 disposed substantially flush with a bottom surface of the firearm grip 10 . Although the pull tab 14 has been described above as being used in a firearm grip 10 , the pull tab 14 may be incorporated into any appropriate portable device such as a camera.
The preceding description has been presented with reference to various embodiments of the invention. Persons skilled in the art and technology to which this invention pertains will appreciate that alterations and changes in the described structures and methods of operation can be practiced without meaningfully departing from the principle, spirit and scope of this invention.
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A grip for attachment to a firearm is provided. The firearm grip includes a housing having an internal storage cavity and a pull tab fixedly attached to the housing. The pull tab includes a body and a stopper attached to the body, which removably engages a wall that defines an open end of the internal storage cavity to removably cover the internal storage cavity.
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BACKGROUND OF THE INVENTION
The present invention relates to an electronic device such as a portable telephone which permits the use of the electronic device when an authentic user identification card on which personal information of the holder (subscriber) is recorded, and a unique information management method.
In recent years, people often carry cards such as credit cards on which personal information is recorded. Along with this, crimes of illicit copy and misuse of cards without any permission of authentic holders are increasing. In the field of electronic devices such as portable telephones, there is recently proposed a system of enabling communication by mounting a user identification card called a SIM (Subscriber Identity Module) card on a telephone main body. The SIM card on which personal information of the holder is recorded is always inserted into a telephone, and the telephone is turned on/off in accordance with whether the telephone is used or not.
Even if the user does not own a telephone, or the user cannot use his/her own telephone because of a dead battery or the like, the user can make speech communication using his/her own ID code by inserting his/her SIM card into the telephone of another person or a public telephone. In this case, charging processing can target the holder of the SIM card. Using a telephone owned by another person, the cardholder can make a call by one-touch operation on the basis of memory dial data stored in the SIM card.
Even such a convenient user identification card such as a SIM card may be illicitly copied and misused without any permission of the authentic holder, similar to a credit card. If the user identification card is lost, the authentic holder notifies the loss or theft of the card. However, if the card is returned after being removed from an electronic device and copied without any permission of the holder, the holder cannot recognize illicit copy of the card.
For this reason, the conventional system suffers the problem that an electronic device such as a portable telephone is misused to charge the card holder owing to the malicious intent of another person who illicitly copied the user identification card. The personal information of the authentic holder is read from the user identification card and leaks out.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an electronic device for preventing illicit copy of a user identification card or leakage of personal information recorded on a user identification card, and a unique information management method.
To achieve the above object, according to the present invention, there is provided an electronic device comprising a device main body whose use is permitted by inserting an authentic user identification card on which personal information of a holder is recorded, card control means for detecting removal/insertion of the user identification card from/into the device main body during a power-off state, and device control means for displaying a warning representing removal/insertion of the card on the basis of a detection result of the card control means in power-on operation.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram showing a portable telephone according to an embodiment of the present invention;
FIG. 2 is a perspective view showing the portable telephone in FIG. 1;
FIG. 3 is a flow chart showing a control operation of a SIM card controller in FIG. 1;
FIG. 4 is a flow chart showing another control operation of the SIM card controller in FIG. 1;
FIG. 5 is a flow chart showing the control operation of a controller when the power switch is pressed; and
FIG. 6 is a view showing a state in which the portable telephone of the present invention receives radio waves from three base stations.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention will be described in detail below with reference to the accompanying drawings.
FIG. 1 shows a portable telephone according to an embodiment of the present invention, and FIG. 2 shows the portable telephone in FIG. 1 . This embodiment will exemplify a portable telephone as an example of an electronic device.
As shown in FIG. 2, a portable telephone 20 has a key operation portion 1 and display 2 which are arranged on upper and lower portions of the front surface. The key operation portion 1 includes many dial keys corresponding to figures, characters, and various other symbols such as “#” and “*”, power switches, and the like. The display 2 is formed from a liquid crystal display device, and displays various messages on the screen.
A microphone 3 for inputting speech to be transmitted is arranged at the lower portion of the portable telephone 20 , and a loudspeaker 4 for outputting a speech signal such as received speech or a ringing tone is arranged above the display 2 . An antenna 5 is freely extendably attached to the upper end of the portable telephone 20 . A slot (not shown) for detachably inserting a SIM card 6 is formed on the back side of the portable telephone 20 . The SIM card 6 is inserted into the slot to make electrical connection to a SIM card controller 7 via a serial interface (to be referred to as a serial I/F hereinafter) 8 .
As shown in FIG. 1, the SIM card 6 incorporates a nonvolatile memory 61 which stores personal information such as a telephone number, the account number of a bank, or a telephone directory. The SIM card controller 7 always monitors via the serial I/F 8 whether the SIM card 6 is inserted into the slot.
In addition to the key operation portion 1 , display 2 , SIM card 6 , and SIM card controller 7 , the portable telephone 20 comprises a controller 9 formed from a microcomputer or the like to control the overall portable telephone 20 , the antenna 5 , a transmitter/receiver 10 connected to the antenna 5 , a data converter 11 connected to the transmitter/receiver 10 , a speech processor 12 connected to the data converter 11 , the microphone 3 and loudspeaker 4 that are connected to the speech processor, a memory 13 , a primary battery 14 , a secondary battery 15 , and a power controller 16 .
The key operation portion 1 is connected to the controller 9 , and an operation signal from the key operation portion 1 is input to the controller 9 . The display 2 is connected to the controller 9 , and display operation of the display 2 is controlled by the controller 9 . The memory 13 and SIM card controller 7 are connected to the controller 9 . The memory 13 stores control programs for communication (speech communication and mail transmission/reception) and various data.
The slot of the SIM card 6 is formed on the back side of the primary battery 14 , and exposed by removing the primary battery 14 . The SIM card 6 is removed/inserted while the primary battery 14 is kept removed, so the SIM card 6 and SIM card controller 7 must operate even while the primary battery 14 is removed. Thus, the SIM card 6 and SIM card controller 7 receive power from the secondary battery 15 mainly used to back up a timepiece function in the portable telephone.
The primary battery 14 is connected to the controller 9 , and the secondary battery 15 is connected to the SIM card 6 and SIM card controller 7 . The power controller 16 is connected between the primary battery 14 and the secondary battery 15 . In this connection, the power controller 16 converts the voltage of the primary battery 14 into a predetermined power supply voltage, and supplies the power supply voltage to the respective building circuits of the portable telephone 20 including the controller 9 . When the primary battery 14 is mounted in the portable telephone 20 , the power controller 16 supplies a voltage from the primary battery 14 to the SIM card 6 and SIM card controller 7 . When the primary battery 14 is removed, the power controller 16 supplies a voltage from the secondary battery 15 to the SIM card 6 and SIM card controller 7 .
The operation of the portable telephone 20 having this arrangement will be described with reference to the flow chart shown in FIG. 3 .
While the portable telephone 20 is OFF, the SIM card controller 7 periodically transmits an inquiry signal to the SIM card 6 via the serial I/F 8 (step S 71 ), and checks whether the SIM card 6 responds to the inquiry signal (step S 72 ). With this operation, the SIM card controller 7 always monitors whether the SIM card 6 is inserted into the slot. If the SIM card 6 does not respond, the SIM card controller 7 determines that the SIM card 6 is not connected and is removed from the slot, and stores in a memory 7 a the current time and position information (base station number) of the portable telephone 20 sent from a corresponding base station (step S 73 ).
In this manner, the memory 7 a stores SIM card removal/insertion information including the removal time of the SIM card 6 and position information of the portable telephone 20 at that time. Note that the SIM card removal/insertion information may be only the time or the date and time. The SIM card controller 7 may monitor whether the SIM card 6 is inserted into the slot only when the primary battery 14 is removed. In this case, power consumption can be suppressed.
A signal received by the antenna 5 as position information of the portable telephone 20 is decoded by the transmitter/receiver 10 , and necessary information is extracted from the decoded signal by the data converter 11 . The extracted position information is sent to the SIM card controller 7 via the controller 9 . Note that position information is periodically transmitted from the base station. As soon as position information changes, it is sent to the SIM card controller 7 via the controller 9 to always hold the latest position information in the memory 7 a of the SIM card controller 7 .
If the SIM card 6 does not respond, the SIM card controller 7 copies the current position information stored in a given area of the memory 7 a to another area of the memory 7 a , thereby storing the current position information as SIM card removal/insertion information. Note that the latest position information and SIM card removal/insertion information are stored in different areas of the memory 7 a , but may be respectively stored in two independent memories.
Another operation of the SIM card controller 7 will be explained with reference to the flow chart shown in FIG. 4 . The SIM card controller 7 checks the physical connection state (e.g., voltage) of the terminal of the serial I/F 8 , and always monitors whether the serial I/F 8 is connected to the SIM card, i.e., the SIM card 6 is inserted into the slot (step S 74 ). If the SIM card 6 is not connected to the serial I/F 8 , the SIM card controller 7 stores the current time and current position information as SIM card removal/insertion information in the memory 7 a (step S 75 ).
The operation of the portable telephone 20 when the power switch of the key operation portion 1 is pressed will be described with reference to FIG. 5 . If the power switch of the key operation portion 1 is pressed, the controller 9 of the portable telephone 20 displays a message prompting input of a PIN code (password number) on the screen of the display 2 . In response to this, the user of the portable telephone 20 operates the key operation portion 1 to input the PIN code (step S 101 ).
The controller 9 collates the PIN code input from the key operation portion 1 with a PIN code registered in the SIM card 6 , and determines whether the user is authentic (step S 102 ). If the input PIN code is correct, the controller 9 refers to the SIM card controller 7 to check whether the SIM card 6 was removed and inserted before power-on operation (step S 103 ). That is, the controller 9 checks whether the memory 7 a stores SIM card removal/insertion information.
If the memory 7 a stores SIM card removal/insertion information, the controller 9 determines that the SIM card 6 was removed and inserted before power-on operation, and displays the SIM card removal/insertion information on the screen of the display 2 (step S 104 ). The controller 9 displays a message on the screen of the display 2 to confirm whether the SIM card removal/insertion information is saved (step S 105 ).
If the user designates saving of the information by operating the key operation portion 1 , the SIM card removal/insertion information is kept saved in the memory 7 a , and can always be checked. If the user designates erase of the information by operating the key operation portion 1 , the controller 9 erases the SIM card removal/insertion information stored in the memory 7 a via the SIM card controller 7 (step S 106 ). Then, the controller 9 enters a normal mode in which communication is done (step S 107 ).
If the memory 7 a does not store SIM card removal/insertion information (NO in step S 103 ), the controller 9 determines that the SIM card 6 was not removed or inserted before power-on operation, and immediately enters the normal mode.
In the normal mode, a signal received by the antenna 5 is demodulated by the transmitter/receiver 10 , and converted into speech data by the data converter 11 . The converted speech data is converted into a transmission signal (analog speech signal) by the speech processor 12 , and output from the loudspeaker 4 . To the contrary, a reception signal (analog speech signal) input from the microphone 3 is converted into speech data by the speech processor 12 , and converted into communication data by the data converter 11 . The converted communication data is modulated by the transmitter/receiver 10 , and transmitted from the antenna 5 .
In mail reception, a signal received by the antenna 5 is demodulated by the transmitter/receiver 10 , and converted into communication data. The converted communication data is converted into character data by the data converter 11 , and displayed on the display 2 . In mail transmission, character data input from the key operation portion 1 or stored in the memory 13 in advance is converted into communication data by the data converter 11 . The converted communication data is modulated by the transmitter/receiver 10 , and transmitted from the antenna 5 .
As described above, in the portable telephone 20 of this embodiment, whether SIM card removal/insertion information is written in the memory 7 a of the SIM card controller 7 is detected before a service starts upon power-on operation. Accordingly, whether the SIM card 6 was removed and inserted before power-on operation is determined. If the SIM card 6 is determined to have been removed and inserted, a card removal/insertion warning is issued by informing the user of SIM card removal/insertion information including the removal time of the SIM card 6 or the like.
If the user of the portable telephone 20 does not remember the removal/insertion represented by this warning, he/she can estimate when and where the SIM card 6 was removed by a third party, from the SIM card removal/insertion information displayed on the display 2 . In this case, the user immediately takes the cancellation procedure of the SIM card 6 with respect to the company of the mobile communication system, and prevents misuse of the SIM card 6 . If the card 6 is removed while the portable telephone 20 is ON, warning display including an alarm sound is sent right away.
In this embodiment, the removal time and position information of the SIM card 6 are stored as SIM card removal/insertion information in the memory 7 a . Moreover, the field strength of the base station when the SIM card 6 was removed may be stored as SIM card removal/insertion information in the memory 7 a . This field strength information can be obtained by the transmitter/receiver 10 which demodulates a signal received by the antenna 5 , and is sent to the SIM card controller 7 via the controller 9 . This enables further specifying the removal place of the SIM card 6 .
The field strengths of a plurality of base stations when the SIM card 6 was removed are stored as SIM card removal/insertion information in the memory 7 a , which allows specifying the removal location of the SIM card 6 in more detail. For example, a W-CDMA (Wideband-Code Division Multiple Access) portable telephone 20 receives radio waves from three base stations BS 1 , BS 2 , and BS 3 , as shown in FIG. 6 . Thus, the field strengths of the three base stations BS 1 to BS 3 when the SIM card 6 was removed can be stored as SIM card removal/insertion information in the memory 7 a.
In this embodiment, SIM card removal/insertion information is written once. Alternatively, new SIM card removal/insertion information may be additionally written in the memory 7 a every time removal/insertion of the SIM card 6 is detected. In this case, the log of SIM card removal/insertion information corresponding to the number of removal/insertion operations of the SIM card 6 can be recorded. Note that all the log of SIM card removal/insertion information may be erased at once in step S 105 of FIG. 5, or part thereof may be erased.
In this embodiment, SIM card removal/insertion information is displayed. However, when specific information is not wanted to be recognized by the user, e.g., private information such as position information (base station number) or field strength information is not wanted to be recognized, only information which can be disclosed to the user (e.g., removal time of the SIM card 6 ) may be displayed without displaying these pieces of information. In this case, SIM card removal/insertion information such as position information or field strength information is analyzed when a person in charge of a mobile communication system company carries the portable telephone to the service center.
In this embodiment, the SIM card controller 7 detects removal/insertion of the SIM card 6 in power-off operation of the telephone, and displays removal/insertion information of the SIM card 6 as a warning. Alternatively, removal/insertion of the SIM card 6 may be detected regardless of power-on/off operation of the telephone. In this case, a warning is displayed in the first power-on operation after the SIM card 6 is removed/inserted.
This embodiment has exemplified a portable telephone as an example of an electronic device which permits its use when an authentic user identification card is inserted. The present invention is not limited to this, and may be applied to another electronic device. Position information includes position information representing a single radio zone, and position registration information including a plurality of radio zones.
As has been described above, according to the present invention, a warning is issued in power-on operation when removal/insertion of a user identification card before power-on operation is detected. This allows monitoring illicit removal/insertion of the user identification card. As a result, the user can recognize the possibility of misuse of the user identification card or leakage of personal information recorded on the user identification card.
Since removal/insertion information representing that the user identification card was removed and inserted before power-on operation is written in a memory means, the removal/insertion information can be saved and always be checked.
If removal/insertion information is written every time a detection means detects removal/insertion of the user identification card, the log of removal/insertion information corresponding to the number of removal/insertion operations of the user identification card can be recorded.
When removal/insertion information is information representing the removal time of the user identification card, the holder can know the time when the user identification card was illicitly removed and inserted.
When removal/insertion information is information representing the removal location of the user identification card, the holder can know the location where the user identification card was illicitly removed and inserted.
When removal/insertion information is information representing the field strength of the base station when the user identification card was removed, the holder can specify in more detail the location where the user identification card was illicitly removed and inserted.
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An electronic device includes a device main body, card controller, and device controller. The use of the device main is permitted by inserting an authentic user identification card on which personal information of a holder is recorded. The card controller detects removal/insertion of the user identification card from/into the device main body during a power-off state. The device controller displays a warning representing removal/insertion of the card on the basis of the detection result of the card controller in power-on operation. A unique information management method for the electronic device is also disclosed.
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The invention relates to the enrichment of photosynthetic microorganisms in organic selenium, in particular using selenohydroxy acid compounds, and more particularly using 2-hydroxy-4-methylselenobutanoic acid, in (D,L) form, or of an enantiomer, salt or ester or amide derivative of this compound, and also to the use of the photosynthetic microorganisms thus enriched in animal or human nutrition, in cosmetics or in pharmacy.
Selenium is a micronutrient essential to humans and mammals in particular (Wendel, A.; Phosphorus, Sulfur Silicon Relat Elem., 1992, 67, 1-4, 404-415). In particular, it participates, in the form of L(+)-selenocysteine or L(+)-selenomethionine (Muller, S. at al., Arch. Microbiol., 1997, 168, 421), in the biosynthesis of selenoproteins such as glutathione peroxidase, thioredoxin reductase and selenoprotein P.
Selenium deficiencies have been reported in humans, in particular in the case of patients subjected to parenteral feeding over long periods of time (Von Stockhausen, H. B., Biol. Trace Elem. Res., 1988, 15:147-155). A daily supplementation of 200 μg of selenium is considered to be safe and adequate for an adult human of average weight (Schnauzer, G. N., J. Am. Col. Nutr., 2001, 20:1-14).
Selenium is found naturally, in two forms: organic and inorganic.
The inorganic compounds are most commonly salts such as sodium selenite or selenate. These compounds are very toxic to humans and most animals.
The organic compounds (organoselenium compounds) are represented in living organisms, in particular, by the amino acids L(+)-selenomethionine, L(+)-methylselenocysteine and L(+)-selenocysteine.
L(+)-Selenomethionine is the main source of organic selenium in humans and animals. However, humans and animals are autoxotrophic for this amino acid, which can be obtained only through the diet.
Selenium should therefore ideally be incorporated into food supplements aimed at treating or preventing a selenium deficiency, in this organic form.
It has thus been possible to demonstrate that supplementing the diet with L(+)-selenomethionine is much less toxic and provides better bioavailability than an intake in the form of sodium selenite (Mony, M. C. et al., J. of Trace Elem. Exp. Med., 2000, 13:367-380).
Currently, metabolic pathways for selenium uptake by living organisms other than those using inorganic selenium, mainly in the form of sodium selenite, and selenomethionine, as substrates are unknown.
A suitable supply of organic selenium can be found in higher plants (wheat, maize, soya, in particular), in which more than 80% of the selenium is made up of L(+)-selenomethionine (Schnauzer, G. N., J. Am. Coll. Nutrit., 2001, 20(1):1-4). However, the selenium concentration in these plants is not sufficient to be able to readily, and less expensively, produce food additives.
One of the approaches explored for obtaining selenomethionine-rich compositions consists in enriching certain microorganisms in organic selenium using inorganic selenium. Once enriched, these microorganisms can be used as starting material for the preparation of food or cosmetic products.
Numerous publications describe, for example, the preparation of selenium-enriched yeasts, and more particularly the yeast Saccharomyces cerevisiae (Oh Tae-Kwang et al., patent KR950006950 of Jun. 26, 1995), for the purpose of using them as such or of incorporating them into food compositions (Moesgaard S. et al., patent DK200200408 of Sep. 16, 2003); or else of obtaining selenium-enriched derived products such as, for example, selenium-enriched bread (Wang Boaquan, patent CN 1817143 of Aug. 16, 2006), milk (Deng Chang-Yi, patent TW565432 of Dec. 11, 2003), eggs (Cui Li et al., patent CN1302723C of Mar. 7, 2007), chocolate (In Gyeong Suk et al., patent KR20040101145 of Nov. 8, 2004) or beer (Jakovleva L. G. et al., patent RU2209237 of Jul. 27, 2003). In the health foods sector, preparations containing selenium-enriched yeasts have also been proposed for pregnant women (Wang Weiyi, patent CN1778199 of May 31, 2006), or else for improving the intestinal microenvironment of hypoglycemic patients (Li Tao Zhao, patent CN1810161 of Aug. 2, 2006). In the dermocosmetics field, compositions containing selenium-enriched yeasts have been developed for the purpose of reducing hair loss (Kasik Heinz, patent DE19858670 of Jun. 21, 2000) or in the prevention of photoaging (Kawai Norihisa et al., patent JP07300409 of Nov. 14, 1995). Pharmaceutical preparations containing selenium-enriched yeasts have been used in the prevention and treatment of inflammatory pathological conditions such as retinopathies related to diabetes (Crary Ely J., patent U.S. Pat. No. 5,639,482 of Jun. 17, 1997), or which are cardiovascular (Nagy P. L. et al., patent HUT060436 of Sep. 28, 1992).
Bacteria, and more particularly probiotic bacteria, have themselves also been the subject of selenium enrichment (Calomme M. et al., Biol. Trace Elem. Res., 1995, 47, 379-383). Lactobacillus acidophilus , but also Lactobacillus reuteri, Lactobacillus ferintoshensis and Lactobacillus buchneri/parabuchneri (Andreoni V. et al., patent U.S. Pat. No. 0,258,964) have been described as selenium-enriched food supplements. Mixtures of probiotics made up of yeasts and lactobacilli, for the purpose of reinforcing the immune system and resistance to diseases (Huang Kehe Qin, patent CN1283171C of Nov. 8, 2006) have been prepared.
However, in all these preparations, the selenium-enriched microorganisms are prepared from inorganic selenium only. Thus, the source of selenium most commonly used consists of sodium selenite or selenate solubilized in the culture media of the microorganisms. The microorganisms thus enriched, although having synthesized satisfactory amounts of organic selenium which can be assimilated by the human organism, often exhibit a high residual level of unconverted inorganic selenium, which can prove to be dangerous to the individual consuming same.
In a previous application published under WO 2006/008190, novel organic compounds of selenohydroxy acid type have been described as being able to serve as precursors for the synthesis of L(+)-selenomethionine in humans and animals.
Surprisingly, the applicant has noted that organic compounds of selenohydroxy acid type, such as those described in application WO 2006/008190, can be incorporated into culture media for enriching various photosynthetic microorganisms in organic selenium. The results obtained have revealed that these compounds make it possible to very efficiently enrich such micro-organisms, in particular in L(+)-selenomethionine, with a yield that is equivalent to, or even higher than, that obtained using the inorganic compounds normally used.
It has thus become apparent that the enrichment of photosynthetic microorganisms in organic selenium using organic compounds of selenohydroxy acid type makes it possible to produce organic selenium free of inorganic selenium, and also to solve the problems of toxicity related to the prior art methods.
The photosynthetic microorganisms thus enriched can be used directly in the food trade in the context of the prevention or treatment of selenium deficiencies, in particular for the purpose of producing pharmaceutical, nutritional or cosmetic products and compositions.
DETAILED DESCRIPTION OF THE INVENTION
The present application relates to the obtaining of photosynthetic microorganisms, that is to say of microorganisms, the growth of which is dependent on a source of energy from light.
The term “microorganism” is intended to mean any living unicellular organism belonging to one of the following kingdoms: monera, protists, mycetes or protozoa, having a eukaryotic or prokaryotic cellular structure, of microscopic or ultramicroscopic size, and having a metabolic and reproductive potential. Said unicellular microorganisms may be involved in the formation of filaments or biofilms.
Preferably, the photosynthetic microorganisms according to the invention are eukaryotic microalgae, more preferably Chlorophyceae of the Chlorella genus, or prokaryotic microalgae such as cyanobacteria, preferably of the Spirulina or Arthrospira genus (spirulin). The latter are well known to those skilled in the art for being used as food supplements, in particular in developing countries.
The term “organic selenium” is intended to mean a collection of molecules containing at least one compound having at least one selenium atom in its chemical structure, capable of being produced by a living organism, such as, in particular, the amino acids selenomethionine, methylselenocysteine and selenocysteine, or peptides or proteins containing them.
The photosynthetic microorganisms thus enriched in selenium can be used as such, or else as a food additive. They can, for example, be dehydrated so as to form a stable powder that can be incorporated into compositions acting as a base for the preparation of transformed products, but can also be used live as probiotics in food product transformation processes, for the purpose of obtaining, for example, fermented milks or drinks.
A subject of the present invention is therefore a novel method for enriching a photosynthetic microorganism in selenomethionine and/or in selenocysteine, characterized in that said photosynthetic microorganism is cultured in a culture medium comprising a compound of selenohydroxy acid type.
Preferably, the compound of selenohydroxy acid type is a compound of general formula (I), or a precursor, a salt or alternatively an ester or amide derivative thereof:
in which formula:
n is equal to 0, 1 or 2;
R 1 is an OH, OCOR 3 , OPO 3 H 2 , OPO 3 R 4 R 5 or OR 6 group;
R 2 is an OH, R 3 , NHR 7 , S-cysteinyl or S-glutathionyl group; it being understood that, when n=1 and R 2 is OH, then R 1 cannot be OH;
R 3 is an alkoxyl, ceramide 1, ceramide 2, ceramide 3, ceramide 4, ceramide 5, ceramide 6a and 6b, S-cysteinyl or S-glutathionyl group, or a group chosen from the following:
Preferably, R 3 is an alkoxyl, S-cysteinyl or S-glutathionyl group;
OR 4 is a (C 1 -C 26 ) alkoxyl, ceramide 1, ceramide 2, ceramide 3, ceramide 4, ceramide 5 or ceramide 6a and 6b group, or a group chosen from the following:
Preferably, OR 4 is a (C 1 -C 26 ) alkoxyl group;
OR 5 is a (C 1 -C 26 ) alkoxyl, ceramide 1, ceramide 2, ceramide 3, ceramide 4, ceramide 5 or ceramide 6a and 6b group, or a group chosen from the following groups:
Preferably, OR 5 is a (C 1 -C 26 ) alkoxyl group;
OR 6 is a pyruvate, lactate, citrate, fumarate, maleate, myristate, palmitate, stearate, palmitoleate, oleate or linoleate group, a natural fatty acids group or a 13-cis-retinoate group;
R 7 is an H or (C 1 -C 26 ) alkyl group, a natural amino acid or a natural amine.
In formula (I) above:
the term “alkyl” is intended to mean a linear or cyclic, optionally branched, optionally fluorinated or polyfluorinated, group containing 1 to 26 carbon atoms, and optionally comprising one or more carbon-carbon double bonds, such as, for example, methyl, ethyl, isopropyl, trifluoromethyl, linoleyl, linolenyl or palmitoyl; the term “alkoxyl” is intended to mean a linear or cyclic, optionally branched, optionally fluorinated or polyfluorinated, group derived from a primary, secondary or tertiary alcohol containing 1 to 26 carbon atoms, and optionally comprising one or more carbon-carbon double bonds, such as, for example, methoxyl, ethoxyl, isopropoxyl, trifluoromethoxyl, linoleoxyl, linolenoxyl or palmitoxyl; structures of radicals of ceramide type are described in particular in “Cosmetic Lipids and the Skin Barrier”, Thomas Förster Ed. 2002, Marcel Dekker, Inc., p 2, FIG. 2; the term “natural” is intended to mean any corresponding compound found in the metabolism of organisms of the plant and animal world, and also in that of humans (Steglich W., Römpp Encyclopedia Natural Products , G. Thieme ed.); the term “oligomer” is intended to mean any compound formed by the linking of 2 to 15 monomers connected to one another by means of an ester-type bond; the term “polymer” is intended to mean any compound formed by the linking of more than 15 monomers connected to one another by means of an ester-type bond.
According to the invention, said compounds of formula (I) are preferably used in the form of calcium salts, zinc salts or magnesium salts, which generally makes it possible to obtain better solubility in culture media, and also better assimilation by the photosynthetic microorganisms.
In one preferred embodiment of the invention, the photosynthetic microorganism is chosen from the group formed by Cyanophyceae and Chlorophyceae. Thus, the photosynthetic microorganism is advantageously selected from Cyanophyceae or Chlorophyceae, preferably chosen from the group formed by Chlorophyceae of the Chlorella genus and Cyanophyceae of the Spirulina or Arthrospira genus.
The invention relates more particularly to the use of a compound of formula (I), chosen (or taken) from
L-2-hydroxy-4-methylselenobutanoic acid, D-2-hydroxy-4-methylselenobutanoic acid, DL-2-hydroxy-4-methylselenobutanoic acid,
or a salt of these compounds.
These compounds are described in application WO 2006/008190.
A subject of the invention is also a photosynthetic microorganism enriched in organic selenium, that can be obtained according to the method of the invention. Such a microorganism generally has an organic selenium content of greater than 500 ppm, preferably greater than 1000 ppm, more preferably greater than 2000 ppm on a selenium equivalent basis, and an inorganic selenium content of less than 0.5%, preferably less than 0.2%, and more preferably less than 0.1% by dry weight of said microorganism. Preferably, the invention relates to the case where the photosynthetic microorganism comprises less than 1.5%, preferably less than 0.5%, more preferably less than 0.1% by mass of inorganic selenium relative to the total selenium.
In other words, the residues of selenium in inorganic form that are present in the photosynthetic microorganisms enriched according to the method of the invention generally account for less than 1.5% of the total selenium present in the microorganisms, which generally represents less than 0.5% of the total dry biomass (dry weight) of said microorganism.
The invention relates most particularly to a photo-synthetic microorganism enriched in organic selenium, characterized in that the content, of said microorganism, of selenium in the form of selenomethionine represents more than 50%, preferably more than 70%, more preferably more than 80%, and even more preferably more than 90%, by mass of selenium, relative to the total selenium present in said photosynthetic microorganism. Such a proportion of selenomethionine represents a considerable and particularly advantageous improvement, in terms of amount and quality of organic selenium present in the microorganism, compared with what was obtained in the prior art.
In particular, the invention relates to the case where the microorganism is characterized in that it is a selenium-enriched Chlorophycea microalga, preferably of the Chlorella genus, and in that said microorganism contains a selenomethionine content of generally greater than 50 micrograms of selenium equivalent per gram (μgSe/g), preferably greater than 70 μgSe/g, and more preferably greater than 100 μgSe/g by dry weight of said microorganism.
The amount of selenium fixed inside the microorganisms in the form of organic molecules (selenomethionine, selenocysteine, or the like) or inorganic molecules (selenium salts) is expressed as mass of selenium per gram (μgSe/g) of dry weight of the microorganisms. In other words, the selenium content of the photosynthetic microorganisms is established by calculating the mass of selenium present in these organic or inorganic molecules, related back to the total dry biomass of the microorganism. In addition, the proportions by mass of selenium present in organic and inorganic form are also established and expressed as percentages relative to the mass of total selenium.
The content of total selenium and selenium in the form of selenomethionine, of the photosynthetic microorganisms according to the invention, can be determined, respectively, by mineralization and enzyme digestion after centrifugation and lyophilization of the microorganisms, for example by following the method according to Lobinsky et al., described in Mester, Z. et al. (2006) Annal. Bioanal. Chem. 385:168-180.
The results obtained according to the present invention, which are illustrated in the examples of the present application, show that the photosynthetic microorganisms, more particularly the Chlorophycea and Cyanophycea microalgae accumulate selenium in the form of selenomethionine in a content of generally greater than 100 micrograms of selenium equivalent per gram (μgSe/g), preferably greater than 200 μgSe/g, more preferably greater than 500 μgSe/g, even more preferably greater than 1000 μgSe/g by dry weight, and even greater than 1400 μgSe/g by dry weight of these microalgae.
The invention therefore relates more particularly to a Chlorophycea or a Cyanophycea enriched in organic selenium, characterized in that its content of organic selenium in the form of selenomethionine is generally greater than 100 μgSe/g, preferably greater than 200 μgSe/g, more preferably greater than 500 μgSe/g, and even more preferably greater than 1000 μgSe/g by dry weight.
Such a Chlorophycea or Cyanophycea enriched in organic selenium is generally characterized in that its content of organic selenium in the form of selenomethionine represents more than 50%, preferably more than 70%, more preferably more than 80%, even more preferably more than 90%, and even more than 95% of the total selenium that it contains, and also in that its residual content of inorganic selenium, generally less than 1.5%, is preferably less than 0.5%, more preferably less than 0.1% of the total selenium that it contains. In general, its residual content of inorganic selenium is less than 1%, preferably less than 0.5%, more preferably less than 0.2%, and even more preferably less than 0.1% of the total biomass of said Chlorophycea, by dry weight.
The invention also relates to the production of food, cosmetic or pharmaceutical products from said photosynthetic microorganisms enriched in selenium according to the method of the present invention. This production makes use of techniques known to those skilled in the art.
The photosynthetic microorganisms according to the invention can also be of use in animal nutrition, in particular for the purpose of obtaining secondary derivatives enriched in organic selenium, for instance fish, milk or eggs.
The derived products and molecules thus obtained are of use in various applications, including those summarized in the preamble, in particular as a cosmetic, pharmaceutical or nutritional agent.
A subject of the invention is also the use of a selenium-enriched photosynthetic microorganism according to the invention, as a cosmetic, pharmaceutical (or therapeutic) or nutritional product (or agent).
The invention also relates to the compositions, generally cosmetic, pharmaceutical or nutritional compositions, comprising said photosynthetic microorganisms.
The invention also relates to a culture medium for a photosynthetic microorganism, characterized in that it comprises one or more of the compounds of formula (I) defined above. Such a culture medium is of use for implementing the method of enriching photosynthetic microorganisms in selenium according to the invention.
In particular, the invention relates to a solid or liquid culture medium comprising at least one compound of formula (I), preferably 2-hydroxy-4-methylselenobutanoic acid or a salt thereof, at a concentration of between 0.5 and 2000 mg/l, preferably between 1 and 1000 mg/l, more preferably between 2 and 500 mg/l, i.e. respectively approximately between 0.2 and 800 mg/l of said compound on a selenium equivalent basis, preferably between 0.4 and 400 mg/l of said compound on a selenium equivalent basis, more preferably between 0.8 and 200 mg/l of said compound on a selenium equivalent basis.
For the microalgae of marine origin, the compounds of formula (I) can be diluted in sterile filtered seawater or in synthetic seawater produced, for example, from the “Reef Crystal” medium from the company Aquarium Systems Inc., so as to form a minimum culture medium.
A method for preparing microalgae according to the invention can in particular comprise one or more of the following steps:
preparing a culture medium, preferably a minimum medium, containing the chemical elements necessary for the growth of a microalga; introducing, into the culture medium, a compound of formula (I), preferably 2-hydroxy-4-methylselenobutanoic acid, as organic source of selenium; adjusting the pH of the mixture to a value of between 6 and 10; placing an inoculum of preculture of said microalga in culture in the mixture thus formed, at a temperature of between 12 and 45° C., with orbital shaking of between 100 and 500 rpm, and an atmosphere that may contain from 0 to 20% of oxygen and from 0.3% to 20% of carbon dioxide, preferably from 24 to 120 hours; centrifuging the mixture at between 4000 and 10 000 rpm for a few minutes, or filtering the mixture through a 0.2 micrometer filter and rinsing the filter through with physiological saline; taking the cell pellet up in physiological saline; centrifuging again at between 4000 and 10 000 rpm for a few minutes; recovering the moist cell pellet which contains the selenium-enriched microalgae.
The moist cell pellet may be lyophilized or air-dried.
Other characteristics and advantages of the invention are given in the examples which follow. The examples hereinafter are provided only by way of illustration and cannot in any way limit the scope of the invention.
EXAMPLES
Example 1
Production of the Chlorella vulgaris microalga enriched in selenium in a medium containing 2-hydroxy-4-methylselenobutanoic acid (THD-177), under autotrophic conditions
Experimental Conditions
The strain used under photoautotrophic conditions is Chlorella vulgaris SAG211-11B: an axenic strain originating from the SAG collection of the University of Göttingen (SAG: Sammlung von Algenkulturen der Universität Göttingen [Collection of Alga Cultures of the University of Göttingen]).
This strain was cultured in the BG-11 medium (blue-green medium) described by [Stanley R Y et al. 1971 Bacteriol. Rev. 35:171-205], the composition of which is the following (per liter):
(1) NaNO 3 : 1.5 g (2) K 2 HPO 4 : 0.04 g (3) MgSO 4 .7H 2 O: 0.075 g (4) CaCl 2 .2H 2 O: 0.036 g (5) Citric acid: 0.006 g (6) Ferric ammonium citrate: 0.006 g (7) EDTA-Na 2 : 0.001 g (8) Na 2 CO 3 : 0.02 g (9) Distilled water 1.0 l (10) Solution of trace elements: 1 ml/l
H 3 BO 3 : 2.86 g MnCl 2 .4H 2 O: 1.81 g ZnSO 4 .7H 2 O: 0.222 g Na 2 MoO 4 .2H 2 : 0.39 g CuSO 4 .5H 2 O: 0.08 g Co(NO 3 ) 2 .6H 2 O: 0.05 g
The pH was adjusted to 7.1 and the medium was autoclaved at 121° C. for 15 minutes.
This strain was cultured at 25° C., 2400+/−200 Lux under photoautotrophic conditions for 2 to 7 days with orbital shaking (80 rpm), OD init660nm =0.05. The OD 660nm of the strain reaches 0.5 in 48 h.
Culture Conditions
The organic source of selenium, namely 2-hydroxy-4-methylselenobutanoic acid (THD-177, Tetrahedron SAS, France, CAS: 873660-49-2) was administered at a concentration of between 0.5 mg/l and 100 mg/l on a selenium equivalent basis, i.e., respectively, 1.25 mg/l and 250 mg/l of 2-hydroxy-4-methylselenobutanoic acid. The compound containing selenium was added just one time (i.e. an amount of between 0.125 mg and 25 mg per 100 ml of culture) at the beginning of the culture, or several times at regular time intervals, the duration of the intervals being between 6 and 24 hours, the culture having been maintained for a period of 2 to 7 days.
Example 2
Production of the Chlorella vulgaris microalga enriched in selenium in a medium containing 2-hydroxy-4-methylselenobutanoic acid (THD-177) (example according to the invention) or in a medium containing sodium selenite (comparative example) under mixotrophic conditions (presence of light and of carbohydrate—glucose—in the medium)
In these tests, the strain used is a strain of Chlorella vulgaris SAG211-11B: an axenic strain originating from the SAG collection of the University of Göttingen (SAG: Sammlung von Algenkulturen der Universität Göttingen [Collection of Alga Cultures of the University of Göttingen]) which was cultured under mixotrophic conditions in the following medium:
Yeast extracts
0.33
g
Beef extracts
0.33
g
Tryptose
0.66
g
FeSO 4
0.66
mg
Glucose
3.3
g
Distilled water
qs 1.0
l
The pH was adjusted to 7.2 and the medium was autoclaved at 121° C. for 15 minutes.
The organic source of selenium, namely 2-hydroxy-4-methylselenobutanoic acid (THD-177, Tetrahedron SAS, France, CAS: 873660-49-2) was administered at a concentration of 20 mg/l on a selenium equivalent basis, i.e. 50 mg/l of 2-hydroxy-4-methylselenobutanoic acid.
The inorganic selenium source (NaSe, sodium selenite) was administered at a concentration of 20 mg/l on a selenium equivalent basis, i.e. 43.9 mg/l of sodium selenite.
The compound containing selenium was added just one time in the exponential growth phase of the Chlorella vulgaris strain (i.e. 3 days after the inoculation).
Preparation of the Samples for Analyses:
After incubation for 7 days, the medium was filtered through a 0.2 micron Nalgene membrane (Ref a-PES, diameter 90 mm), and the cell retentate was rinsed with physiological saline. The wet cell mass was lyophilized for analysis of the constituents containing selenium (total selenium, selenomethionine and sodium selenite).
Analysis of the Constituents Containing Selenium of Chlorella vulgaris
The total selenium was assayed by ICP coupled to detection by mass, after mineralization of the sample. The speciation of the selenium was carried out by high performance liquid chromatography coupled to tandem mass detection, after enzyme digestion of the sample, according to the method described by Lobinsky et al., in Mester, Z. et al. (2006) Annal. Bioanal. Chem. 385: 168-180.
Results
Table 1 below indicates the average values, on a selenium equivalent basis, obtained in triplicate for incubation times of 7 days.
TABLE 1
Analysis of the components containing selenium
of the Chlorella vulgaris microalga
Total Se
SeMethionine
Se(IV)
mgSe/kg
mgSe/kg
mgSe/kg
biomass
biomass
biomass
Addition
1293 ± 23
1274 ± 109
6 ± 1
THD177
(98.5% of
(0.4% of
20 mgSe/l
total Se)
total Se)
Addition
144 ± 5
29 ± 2
4.1 ± 0.4
NaSe
(20% of
(2.7% of
20 mgSe/l
total Se)
total Se)
The results obtained showed, for the same dose of selenium added in the form of THD177 or of NaSe, in this case 20 mgSe/l, that:
nine times more total Se was detected if the addition is carried out in the form of THD177 than if the addition is carried out in the form of NaSe; the level of selenium accumulated intracellularly in the form of selenomethionine, obtained by means of an addition of THD177, is 44 times higher than that obtained by means of an addition in the form of NaSe; the level of selenium accumulated intracellularly in the form of selenomethionine reaches virtually 100% (98.5%) of the intracellular compound forms containing selenium if the addition is carried out in the form of THD177, compared with a level of 20% with NaSe; and that: only 0.4% of Se(IV) in the total selenium was detected if the addition is THD177, whereas 2.7% of Se(IV) were detected in the total selenium in the case of the addition of NaSe.
Example 3
Production of the Arthrospira platensis microalga enriched in selenium in a medium containing 2-hydroxy-4-methylselenobutanoic acid (THD-177) (example according to the invention) or in a medium containing sodium selenite (comparative example) under autotrophic conditions
In these tests, the strain used is a strain of Arthrospira platensis 3054-E0001.
The 3054-50001 strain was cultured under autotrophic conditions in the following medium:
Yeast extracts
0.33
g
Beef extracts
0.33
g
Tryptose
0.66
g
FeSO 4
0.66
mg
Distilled water
qs 1.0
l
The pH was adjusted to 7.2 and the medium was autoclaved at 121° C. for 15 minutes.
The organic source of selenium, namely 2-hydroxy-4-methylselenobutanoic acid (THD-177, Tetrahedron SAS, France, CAS: 873660-49-2) was administered at a concentration of 25 mg/l on a selenium equivalent basis, i.e. 62.5 mg/l of 2-hydroxy-4-methylselenobutanoic acid.
The inorganic selenium source (NaSe, sodium selenite) was administered at a concentration of 25 mg/l on a selenium equivalent basis, i.e. 54.4 mg/l of sodium selenite.
The compound containing selenium was added just one time, just after the inoculation with the Arthrospira platensis strain (i.e. T=0).
Preparation of the Samples for Analyses:
After incubation for 10 days, the cell pellet was filtered through a 0.2 micron Nalgene membrane, and the cell retentate was rinsed with physiological saline. The wet cell mass was lyophilized for analysis of the constituents containing selenium (total selenium, selenomethionine and sodium selenite).
Analysis of the Constituents Containing Selenium of Arthrospira platensis
The total selenium was assayed by ICP coupled to detection by mass, after mineralization of the sample. The speciation of the selenium was carried out by high performance liquid chromatography coupled to tandem mass detection, after enzyme digestion of the sample, according to the method described by Lobinsky et al., in Mester, Z. et al. (2006) Annal. Bioanal. Chem. 385: 168-180.
Results
Table 2 below indicates the average values, on a selenium equivalent basis, obtained in triplicate for incubation times of 10 days.
TABLE 2
Analysis of the components containing selenium
of the Arthrospira platensis microalga
Total Se
SeMethionine
Se (IV)
mgSe/kg
mgSe/kg
mgSe/kg
biomass
biomass
biomass
Addition
1431 ± 68
1402 ± 47
17.2 ± 0.7
THD177
(98% of
(1.2% of
25 mgSe/l
total Se)
total Se)
Addition
177 ± 2
13 ± 3
5.1 ± 0.3
NaSe
(7% of
(2.9% of
25 mgSe/l
total Se)
total Se)
The results obtained showed, for the same dose of selenium added in the form of THD177 or of NaSe added, in this case 25 mgSe/l, that:
eight times more total Se was detected for an addition carried out in the form of THD177 than for an addition carried out in the form of NaSe; the level of selenium accumulated intracellularly in the form of selenomethionine, obtained by means of an addition of THD177, is 108 times higher than that obtained by means of an addition in the form of NaSe; the level of selenium accumulated intracellularly in the form of selenomethionine reaches 98% of the intracellular compound forms containing selenium if the addition is carried out in the form of THD177, compared with a level of 7% with NaSe; and that: only 1.2% of Se(IV) in the total selenium was detected if the addition is THD177, whereas 2.9% of Se(IV) were detected in the total selenium in the case of the addition of NaSe.
Example 4
Production of the Arthrospira platensis micro-alga enriched in selenium in a medium containing 2-hydroxy-4-methylselenobutanoic acid (THD-177) (example according to the invention)
In these tests, the strain used is a strain of Arthrospira platensis 3054-E0001. A comparison is made between the results
of the previous example, example 3, during which the addition, according to the invention, of the compound containing selenium THD-177 was carried out just one time just after the inoculation with the Arthrospira platensis strain, and a new experiment in which the addition, according to the invention, of the compound containing selenium THD-177 was carried out in the exponential phase of culture of said Arthrospira platensis strain, as in example 2.
Results
Table 3 below indicates the average values, on a selenium equivalent basis, obtained in triplicate for incubation times of 10 days.
TABLE 3
Analysis of the components containing selenium
of the Athrospira platensis microalga
Analysis of the components containing selenium
of the Arthrospira platensis microalga
Total Se
SeMethionine
THD177
Se(IV)
mgSe/kg
mgSe/kg
mgSe/kg
mgSe/kg
biomass
biomass
biomass
biomass
Addition at
1431 ± 68
1402 ± 47
5 ± 1
17.2 ± 0.7
inoculation
(98% of
(0.35% of
(1.2% of
THD177
total Se)
total Se)
total Se)
25 mgSe/l
Addition
1274 ± 16
1078 ± 89
11 ± 2
14 ± 2
exponential
(85% of
(0.86% of
(1.1% of
phase THD177
total Se)
total Se)
total Se)
25 mgSe/l
The results showed that 12% more total selenium and 30% more selenium in the form of selenomethionine were obtained in the “addition at T0” test compared with the “addition in the exponential phase” test. This difference could be the result of the longer contact time between the biomass and the THD177 in the “addition at T0” test than in the other, “addition in the exponential phase”, test.
In both cases, the intracellular Se(IV) level remains low at 1% of total selenium.
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The invention relates to the enrichment of photosynthetic microorganisms in organic selenium using selenohydroxy acid compounds, in particular 2-hydroxy-4-methylselenobutanoic acid, in D or L form, or an enantiomer, salt or ester or amide derivative of these compounds, and also to the use of the microorganisms thus enriched in animal or human nutrition, in cosmetics or in pharmacy.
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BACKGROUND OF INVENTION
The present invention relates generally to an apparatus for checking the functionality of a fuel tank vapor pressure sensor using vacuum produced by a pump at an atmospheric port.
A non-integrated vehicle fuel system includes a normally-sealed fuel tank. Fuel system integrity is verified by the presence of pressure or vacuum created by temperature difference or a leak check pump. If the system holds pressure or vacuum above a certain threshold, the fuel system is considered leak free.
Because the fuel system integrity determination relies upon the tank vapor pressure sensor reading, a rationality check must be performed on the fuel tank vapor pressure sensor. Primary failure modes such as sensor-offset or sensor-stuck-in-range must be checked.
The architecture of a non-integrated fuel system presents unique challenges to verify leak integrity without redundant pressure sensors or excessive emissions. For example, in order to reliably ensure that the indicated fuel tank vapor pressure is correct, the fuel system might, for example, include two pressure sensors and compare the outputs of the sensors. If a difference in output from the sensors is present, the system's diagnostics sets a malfunction indicator warning light. But this technique requires a second sensor, a manifold, and a hose connecting the manifold to a carbon canister.
A need exists for a fuel system and method for checking that the vapor pressure sensor returns to zero and is not stuck-in-range without actually relieving all the pressure or vacuum in the fuel tank. Performance of the system should comply with emission regulations at low cost.
SUMMARY OF INVENTION
A vehicle fuel emissions system includes a fuel tank, a tank pressure sensor indicating a pressure differential between the tank and the port in communication with the atmosphere, a pump for selectively producing vacuum in the tank, and a passage connecting the pump and the pressure sensor external air reference port to the system.
The invention contemplates a method for checking operation of a fuel tank pressure sensor in a sealed fuel system. That method includes using a tank pressure sensor to indicate a magnitude of pressure in the tank, using a pump to produce vacuum in the system, communicating said vacuum to a port communicating with the fuel tank, and checking correct operation of the fuel tank pressure sensor by comparing a pressure change indicated by the tank pressure sensor due to said vacuum with a pressure change due to said vacuum indicated by a second pressure sensor located in the system.
Under normal running conditions, the air reference port hose does not affect the output of fuel tank vapor pressure sensor because the air reference port is open to atmosphere. The system provides a reliable check on the operation of the fuel tank pressure sensor without opening the Diurnal Control Valve (DCV) and without need for a second fuel tank vapor pressure sensor.
The system lowers overall emissions and reduces cost associated with the eliminated second fuel tank vapor pressure sensor, manifold, and a hose connecting the manifold to the carbon canister. The system avoids failure modes that would prevent the second sensor from operating correctly while working concurrently with correct operation of the first sensor.
BRIEF DESCRIPTION OF DRAWINGS
The invention will be more readily understood by reference to the following description, taken with the accompanying drawing, in which the FIGURE is a schematic diagram showing a fuel system for a motor vehicle.
DETAILED DESCRIPTION
The fuel tank emission system 10 shown in the drawing, includes a fuel tank 12 ; a file pipe 14 through which fuel enters the tank 12 ; an evaporative leak check module (ELCM) 20 ; filter 22 ; a normally-closed diurnal control valve (DCV) 24 ; carbon canister 26 , connected by a passage 28 to tank 12 ; fuel tank vapor pressure sensor (FTVPS) 30 ; an atmosphere reference port 32 ; and a purge valve 34 , connected by a passage 36 to an engine 37 . The FTVPS 30 is used to check the fuel system vapor space for the presence of a leak equivalent to about a 0.020 inch (0.508 millimeters) diameter hole.
Fuel vapor generated in tank 12 is at least partially vented through a first vapor flow path, which includes passage 28 and canister 26 . Activated carbon, similar to charcoal, contained in canister 26 collects and stores the hydrocarbons. When the engine is running, air is drawn through canister 26 , and the hydrocarbons are drawn into the engine 37 .
The tank vapor pressure sensor 30 is essentially a membrane exposed on one side of its thickness to fuel tank and canister pressure, and on the opposite side to atmospheric pressure through port 32 .
The ELCM 20 includes a valve 40 , pressure sensor 42 , and pump 44 , preferably a vane pump. Pump 44 communicates though a port 46 with the fuel tank 12 through a second vapor flow path, which includes passages 48 , 49 and a filter 22 . Passages 48 , 50 connect filter 22 to valve 40 . The air line 56 may include the evaporative leak check module (ELCM) 20 . The ELCM filter 22 filters the air flow to the ELCM 20 .
The evaporative leak check module 20 includes the ELCM diverter valve 40 , vacuum pump 44 and ELCM pressure sensor 42 . A reference orifice 70 may also be included within the evaporative leak check module 20 .
The diverter valve 40 includes a first path 62 and a second path 64 , which pass through valve 40 . In a first position as illustrated in the FIGURE, air is directed through path 62 of the diverter valve 40 directly from its input to the DCV 24 . In the second position, the diverter valve 40 is controlled upward so that the vacuum pump 44 is in use, thereby creating vacuum in the passage 55 , 56 , 64 up to the diurnal control valve 24 . In either case, the pressure sensor 42 generates a pressure signal corresponding to the pressure within the ELCM 20 .
The pump's port 52 communicates with valve 40 through passage 64 and with pressure sensor 42 , passage 56 and the DCV 24 through passage 55 . Pressure sensor 42 preferably indicates absolute pressure in the system.
The valve 40 of the ELCM 20 is a two-position valve, actuated by a solenoid 58 and compression spring 60 . Valve 40 moves alternately to and from the position shown in the FIGURE wherein passages 50 , 56 are interconnected through valve passage 62 . In the position shown in the FIGURE, the vacuum pump 44 is isolated from the system. In the alternate position, passage 50 is isolated and vacuum pump 44 can apply a pressure differential to create vacuum in passages 55 , 56 and 64 .
Through the use of diverter valve 40 , pump 44 has ability to draw a reference vacuum on orifice 70 corresponding in magnitude to the vacuum in a fuel system having a leak through an orifice of about 0.20 inch diameter. If pump 44 can produce a larger vacuum on the complete fuel system 10 than the reference vacuum, the system 10 is assumed to be sealed. If the pump cannot produce vacuum as great as the reference vacuum, the system is assumed to be unsealed or leaking.
A pressure relief valve 66 , located in a passage 68 , is connected to the DCV 24 and passage 56 . The reference orifice 70 is located between pressure sensor 42 and passage 56 .
A low-cost snorkel hose 72 has an open end connected to the atmospheric reference port 32 of the FTVPS 30 . Hose 72 is connected through a tee fitting 74 in passage 56 between the DCV 24 and pump 44 .
An engine control module (ECM) 80 communicates through electronic data lines to a fuel level sensor 82 in the fuel tank 12 , the solenoid 83 of purge valve 34 , the FTVPS 30 , the solenoid 58 and pressure sensor 42 of the ELCM 20 , and the solenoid 85 of the DCV 24 .
Unlike typical evaporative emissions systems that are vented to atmosphere during normal operation, the evaporative emissions system 10 is closed to atmosphere by the DCV 24 . The FTVPS 30 is located on the sealed side of the DCV 24 , but it is undesirable to open the DCV 24 when the gasoline engine 37 is not operating. Opening the DCV 24 without the engine running would allow the escape of hydrocarbon vapors.
In the sealed system 10 , pressure in the fuel system will vary from negative to positive during normal operation and while the vehicle is parked with the engine off. No operating condition exists in which pressure in the system is predictably zero. Because of this, the fuel tank vapor pressure sensor 30 could be stuck-in-range at a pressure reading, in which case it would be impossible to diagnose the condition. A reliable way is needed to confirm that the fuel tank vapor pressure sensor 30 is operating correctly and reading the actual pressure in the fuel tank 12 .
To reliably ensure that fuel tank vapor pressure sensor 30 is operating correctly, while the engine is not running, pump 44 in the ELCM 20 is used to produce vacuum, which is communicated to the atmospheric reference port 32 of the fuel tank vapor pressure sensor 30 through hose 72 .
The fuel tank vapor pressure sensor 30 is intended to read the pressure differential between the sealed system 10 and atmosphere. In the illustrated example, the vapor pressure sensor 30 is attached directly to the carbon canister 26 . The snorkel hose 72 connects the atmospheric reference port 32 on the fuel tank vapor pressure sensor to passage 56 between the DCV 24 and the ELCM 20 with the use of tee fitting 74 . Pump 44 in the ELCM 20 creates a vacuum which is applied to the atmospheric reference port 32 on fuel tank vapor pressure sensor 30 through hose 72 .
Pump 44 can produce up to 4 kPa of pressure differential between the sealed system 10 and atmosphere, which is great enough to cause a change in output of fuel tank vapor pressure sensor 30 . The change in output of fuel tank vapor pressure sensor 30 can be used to confirm that the sensor is operating properly. The pressure sensor 42 in the ELCM 20 produces a signal representing absolute pressure, which is used in a rationality test to confirm that the output of fuel tank vapor pressure sensor 30 changed the correct amount when vacuum is produced in the system by pump 44 .
Under normal running conditions, the air reference port hose 72 does not affect the output of fuel tank vapor pressure sensor 30 because the air reference port 32 is open to atmosphere. The air reference port 32 is protected from water splash. The system provides a reliable check on the operation of the fuel tank pressure sensor 30 without opening the DCV 24 .
While certain embodiments of the present invention have been described in detail, those familiar with the art to which this invention relates will recognize various alternative designs and embodiments for practicing the invention as defined by the following claims.
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A vehicle fuel emissions system includes a fuel tank, a tank pressure sensor indicating a pressure differential between the tank and a port communicating with the atmosphere, a pump for selectively producing vacuum in the tank, and a passage connecting the pump and a pressure sensor air reference port external to the system.
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This application claims priority to and is a continuation of U.S. application Ser. No. 12/960,208, which was filed on Dec. 3, 2010 and is entitled “Variable Duty Cycle Switching with Imposed Delay.”
BACKGROUND
The present invention relates to solid-state power conversion and more specifically to solid-state switch management, feedback, and control.
An inverter is an electrical device that uses switches to convert direct current into alternating current. The switches open and close in a pattern to create a reciprocating current back and forth through a load. Conditioning and other circuit functionality can be applied to the resulting reciprocating current to change or manage its frequency, voltage, and size. Switches in inverters may be both mechanical and solid-state.
Devices performing the converse function of inverters are called rectifiers. Rectifiers function to convert an alternating current into a direct current. Like inverters, rectifiers may use switches that open and close in a pattern to create a single polarity current through a load. Also like inverters, rectifiers may be both mechanical and solid-state.
Solid-state inverters and rectifiers may use electronic switches, including FETs and MOSFETs, to convert direct current into alternating current or alternating current into direct current. Solid-state inverters may be employed to provide AC power from DC sources such as solar panels, batteries, and fuel cells while solid-state rectifiers may be used to convert alternating current from a power grid or AC generator into direct current for use to charge batteries, driving DC motors, or powering other DC current loads.
As with all power management systems, conversion losses in both inverters and rectifiers can serve to reduce the amount of power available after the power has been converted to a useable form. The smaller the quantity of the loss the more efficient the inverter or rectifier is considered to be. Power losses may be attributable to switching attributes, including the buildup of electric charge in a circuit, and the opposition to current an electric charge buildup may provide.
Switches in solid-state inverters can be positioned in a two-by-two configuration, commonly referred to as an H-bridge. In this configuration pairs of switches can fire to create alternating current through the load.
Embodiments provided herein are directed to, among other things, inverters, rectifiers, switch topologies for power conversion, current conditioning, voltage conditioning, current and voltage sensing, switch feedback, switch timing, and switch topology. Other embodiments may be plausible as well.
BRIEF SUMMARY
Embodiments may include processes, machines, and articles of manufacture. These embodiments may serve to provide switch operation having reduced switching losses or improved signal output, or both. Embodiments may include the use of upper and lower duty cycle boundaries to manage the operation and timing of switching operations. In embodiments, these duty cycle boundaries may be constants or variable and may be offset as well. Switching losses may be controlled or managed through the use of these duty cycle boundaries.
Embodiments may further include switch-side current sensing and logical current sensing for feedback control. Still further, embodiments may also include secondary global feedback control. These and other embodiments are described throughout and should be seen as exemplary and not limiting on the scope of invention.
Embodiments may include solid-state circuits having power train switches and diodes, sensor circuits configured to provide a sensor signal indicative of current flowing from the power train switches, and a logic circuit electrically coupled to the power train switching circuit, the logic circuit configured to send switching instructions for switching switches in the power train switching circuit. These switching instructions may include switching a pair of switches on and off, independently switching a third switch in the power train on and off, and holding open a fourth switch in the power train. In embodiments, the switches may have various configurations including MOSFET transistors, IGBT transistors, and other configurations as well. In embodiments the diodes may be included within the switches, as with MOSFET transistors, and may be separate as well, as with p-n junction diodes connected across IGBTs in an antiparallel configuration.
Embodiments may also include: a power converter having a switching type step-down converter circuit; having an input port to couple to a supply voltage; and having an output port to provide an output voltage at a magnitude that is lower than a magnitude of the supply voltage. The power converter may further contain a control circuit to receive a feedback signal and regulate the magnitude of the output voltage in response thereto, a switching type DC/AC converter circuit having a primary side and a secondary side, a rectifier circuit having an input port and an output port, the input port being coupled to the secondary side of the DC/AC converter circuit, and a feedback circuit to generate the feedback signal in response to the output port of the rectifier circuit.
Embodiments may also include converting direct current to alternating current. These embodiments may include generating a command signal representing a desired current, sensing an existing current in an H-bridge switch powertrain, comparing the command signal with the sensed current, and generating a first set of switching signals, the set including signals to alternately switch a first switch and a second switch in the H-bridge powertrain on and off, independently turn a third switch in the H-bridge powertrain on and off, and hold a fourth switch of the H-bridge powertrain open.
Embodiments may include converting alternating current to direct current. These conversions may include generating a command signal representing a desired current, sensing an existing current in a switch powertrain, comparing the command signal with the sensed current, and generating a first set of switching signals, the set including signals to alternately switch a first switch and a second switch in the powertrain on and off, independently turn a third switch in the powertrain on and off, and hold a fourth switch of the powertrain open.
According to aspects of embodiments of the invention, a power conversion may be provided. Embodiments may include: receiving a supply voltage and generating a first output voltage having a magnitude that is higher or lower than a magnitude of the supply voltage, where the act of generating comprises regulating the first output voltage in response to a feedback signal; generating an AC voltage from the first output voltage or generating a DC voltage from the first output voltage; rectifying the AC voltage to provide a DC voltage or inverting the DC voltage to provide an AC voltage; and generating a feedback signal in response to the generated voltage.
This invention and/or embodiments thereof will be further described and appreciated from the accompanying detailed description in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
FIG. 1 shows and H-bridge switching topology of a power circuit as may be employed in accord with embodiments of the invention.
FIG. 2 shows an alternating current held between top and bottom duty-cycle boundaries as may be employed in accord with embodiments of the invention.
FIG. 3 shows power conversion circuitry including top and bottom boundary comparators as may be employed in accord with embodiments of the invention.
FIG. 4 shows top and bottom voltage boundaries for an approximate switching cycle as may be employed in accord with embodiments of the invention.
FIG. 5 shows a current signal for an approximate switching cycle as may be rendered in accord with embodiments of the invention.
FIG. 6 shows a current signal for an approximate switching cycle as may be rendered in accord with embodiments of the invention.
FIG. 7 shows top and bottom voltage boundaries for an approximate switching cycle as may be employed in accord with embodiments of the invention.
FIG. 8 shows a current signal for an approximate switching cycle as may be rendered in accord with embodiments of the invention.
FIG. 9 shows circuitry, including feedback circuitry, as may be employed in accord with embodiments of the invention.
FIG. 10 shows power conversion circuitry using switch side leg sensor resistors as may be employed in accord with embodiments of the invention.
FIG. 11 shows analog multiplexer circuitry as may also be employed with the switch side leg sensor resistors in accord with embodiments of the invention.
FIG. 12 shows a schematic of circuit logic parameters as may be employed in accord with embodiments of the invention.
FIG. 13 provides features as may be individually or cumulatively employed in processes in accord with embodiments of the invention.
FIG. 14 shows topology of a power converter in accord with embodiments of the invention.
DETAILED DESCRIPTION
Embodiments of the invention may provide switching, sensing, or filtering techniques as may be employed by or for power conversion circuits. These can include the use of solid-state switching methodologies to control or assist switching management and timing, as well as to control or assist circuit feedback and sensing. Embodiments can include the use of software to control or assist switching management, switching timing, and circuit feedback and sensing.
These methodologies can include the introduction of fixed or variable duty-cycle boundaries to reduce or eliminate power loss associated with imperfect switching circuits. These methodologies can also include or employ feedback and filtering circuits to control currents or voltages between or around fixed and variable boundaries and to smooth output power signals from power conversion circuits.
Switch circuitry imperfections addressed in embodiments can include, but are not limited to reducing electrical charges, commonly called reverse recovery charges, which can serve to retard current flow. These reverse recovery charges may be formed or serve to impede current flow in p-n junction diodes, including those found in transistor body diodes as well as diodes used outside of transistors, but in conjunction with them. Different or additional sources and attributes of imperfect switch circuitry may also be addressed in embodiments. Still further, in certain embodiments, little or no measurable improvement to switch circuitry imperfections may be accomplished or perceived.
In embodiments, inverter switches may be fired in certain sequences and in certain groups. A result of these methodologies may provide for reduced MOSFET or other switch body diode recovery losses. These timing sequences may include having switches operate in critical conduction mode for prescribed periods of time and at times triggered by hysteresis type feedback and sensing.
Through the use of fixed or variable voltage boundaries, MOSFETs or other switches with antiparallel diodes may be timed and fired such that body diode losses or other diode losses associated with reverse current switching may be diminished if not eliminated. In other words, switch timing, switch methodologies, and switch topologies may be used that provide dead time for latent electrical charges in antiparallel diodes or other electrical charge impediment to dissipate before switches may be fired again and currents reversed.
Further to the above, embodiments may provide that current in a monitored powertrain be sensed directly from an inductive filter using a small resistance or shunt to produce a small voltage proportional to the current. This small voltage, which may be less than 50 mV, may be amplified to several volts in order to improve resolution and noise immunity. In embodiments, based on the difference in the measured current and a commanded current, a duty-cycle command may be produced. This duty-cycle command may be converted to switching signals that control switching MOSFETs in the power train. And, in embodiments, this command duty-cycle may adjust for or seek to reduce body-diode conduction loss problems through timing and delay firing methodologies. In so doing, variable and shifted boundaries serving to set the switch triggering signals may be used.
Still further, in embodiments, modified hysteresis control may also be used. In these embodiments, the sensed current may also be compared to a commanded current. If the sensed current exceeds the commanded current then the MOSFETs or other switches may be switched to redirect the current to decrease. Likewise, if the sensed current goes below the commanded current the MOSFETs or other switches may be switched to redirect the current increase. In so doing the actual current may oscillate back and forth around the commanded current.
Also, in these hysteresis embodiments, the sensed current may be compared to variable offset boundaries that serve to reduce switching losses associated with diode reverse recovery. Here, as well as in other embodiments, a reduction in switching losses may be realized by introducing a very short delay of dead time between the commutation of switches. This dead time may provide sufficient time for body diode conduction to dissipate, thereby reducing associated switching losses. Since current in the switches returns to zero or near zero in embodiments, the inverter may be considered to be a critical conduction mode inverter.
FIG. 1 shows a power train topology power circuit 100 . Visible in the circuit of FIG. 1 are MOSFET switches 110 , 112 , 114 , and 116 , dc voltage source 140 , inductor 120 , inductor current 150 , and output/line voltage 130 . Also visible in FIG. 1 are body diodes 111 , 113 , 115 , and 117 . These body diodes are resident within MOSFET switches 110 , 112 , 114 , and 116 , but are explicitly shown to explain switching methodology of embodiments described herein.
In embodiments, including FIG. 1 , a sensed current may be compared to a target current in order to control the switches of the power train of a circuit. When the sensed current exceeds the commanded current by some predetermined amount, the MOSFET switches 110 , 112 , 114 , and 116 may be switched to redirect the current to decrease its flow. Likewise, if the sensed current goes below the commanded current by the predetermined amount, the MOSFET switches may be switched to redirect the current increase. In this way, the actual current oscillates back and forth around the commanded current.
In embodiments, this switching methodology may be further defined such that when i o 150 is positive, MOSFETs 114 and 112 may switch rapidly, MOSFET 111 may be off, and MOSFET 116 may be held on. More specifically, when MOSFET 114 is on, i o 150 may increase towards a threshold that is related to the desired output current of the power circuit 100 . When this threshold is reached, MOSFET 114 may be turned off and MOSFET 112 may be turned on. Subsequent to this switching activity, there may also be a very short delay, designated as dead time or deadband between the commutation of the two switches 112 and 114 . During this deadband time, the body diode of MOSFET 112 may turn on as the inductive current continues to flow. Once MOSFET 112 turns on, most or all of the current may flow through MOSFET 112 instead of its body diode 113 . Also, once MOSFET 112 is on, the current i o 150 may decrease toward zero. At zero, there may be little if any current flowing in either MOSFET 112 or its body diode 113 . In this way, switching loss experienced by either the MOSFET 112 or the body diode 113 may be reduced.
Conversely, when the current is flowing in the opposite direction, the timing and activity of the switches may be reversed. For example, MOSFETs 110 and 116 may switch rapidly while MOSFET 114 may be off and MOSFET 112 may be held on. Thus, when MOSFET 110 is on, i o 150 may move towards a threshold that is related to the desired output current of the inverter. When this threshold is reached, MOSFET 110 may be turned off and MOSFET 116 may be turned on.
By following this switching methodology, the current may reach zero each switching cycle. However the current may not dwell there for a significant or substantial amount of time.
While remaining at zero may serve to discharge MOSFET body diodes and reduce associated power losses, the output signal may become too distorted when zero lag times are too long. Likewise, when zero crossing times are too short, the output signal may contain less noise, but the power losses may be more significant. The use of variable duty-cycle boundaries may be used in embodiments when waveform integrity is desired. The startup noise may be generated when circuit components are settling in. Distortion, once the circuit is up and running, is not preferred as it can cause failure to meet standards or other problems.
The power train of FIG. 1 , as well as other embodiments, may also include further filtering to smooth the output power. In a preferred embodiment, the frequency of the switching will be high such that smaller inductors may be used in “LCL” and other types of filters.
FIG. 2 shows duty-cycle boundaries as may be employed in embodiments. As can be seen the top duty-cycle boundary may be sinusoidal and the bottom duty-cycle boundary may be constant. In FIG. 2 , the boundaries have been shifted by −0.5 A for the bottom boundary and by +0.5 A for the top boundary. The current generated from these boundaries may be approximately half of the distance between the boundaries. In this embodiment, as well as in others, the bottom boundary may be offset from the OA axis to reduce switching losses. When this offset is performed, the upper boundary may be offset by a similar amount to maintain power circuit output.
As can be seen in FIG. 2 , with the offset, the top boundary 210 is defined by the curve 2i*+0.5 and the bottom boundary 220 is defined by the constant −0.5 A. The triangles within the boundaries represent thousands of oscillations of current through the inductors. These oscillations may be defined by numerous upper and lower boundary curves and boundary constants. The top boundary may be set so that that top value of the current is sinusoidal. The bottom boundary may be set such that it provides that the MOSFET body diodes have had adequate time to recover. In embodiments, as noted, the bottom boundary may be offset from zero amps such that adequate time for discharge of the MOSFET body diodes is provided. During time in which the current is negative, stored charge in the MOSFET body diodes may be dissipated. In a negative cycle, the boundaries may reverse, with the top boundary being a constant value, perhaps +0.5 amps and the bottom boundary being a sinusoidal and offset by −0.5 amps. FIG. 4 shows an example of this.
In embodiments, hysteresis control may be used to control commanded current. As noted, the upper bound may be allowed to vary with the commanded current while the lower bound may be fixed. As shown in FIG. 2 , for a given cycle, the current may form a triangle from i l to i u . For these triangles it can be shown that the average value of the current is
i
_
=
1
2
(
i
u
+
i
l
)
where a preferred upper bound (assuming a fixed lower bound) may be set to
i u =2 ī−i l
In embodiments the lower bound may be set to 0 A. In this instance, the upper bound may be twice the desired current. In other preferred embodiments, the lower bound may be set slightly below 0 A. By setting the bound below 0 A, a stored charge in the body diode may have time to dissipate before a top switch (e.g., MOSFET 114 ) is turned on. In preferred embodiments, some lower bound near and below 0 A may be preferred for minimizing overall loss when conduction, switching loss, and body-diode switching loss, are collectively considered.
Varying the boundaries under different circumstances may be preferred in other embodiments and exemplary boundary configurations are addressed in further detail below.
FIG. 3 illustrates an exemplary power converter with an H-bridge type topology. The timing of the switching events and the use of current sensing may employ embodiments. Likewise, the comparator inputs may exemplify the boundaries described herein and the related and prescribed diode discharges.
FIG. 3 shows a DC power supply 301 that incorporates a power converter circuit 300 in accordance with embodiments of the invention. The power converter circuit of FIG. 3 may be used by itself, as a power supply, or may be combined with one or more other circuits in forming other types of power supply circuits, for example, to provide an AC power supply 302 . Furthermore, sections of the circuit 300 may also be used in rectifiers embodying the invention.
Circuit 300 can be considered to include several main elements: a DC power source 301 , switches 310 , a filter 320 , a sensor circuit 330 , a gain circuit 340 , a comparator circuit 350 , gate drives 375 and 385 , and control circuitry consisting of, for example, a flip-flop 360 and command gates 370 , 380 . These main elements may be used to output the AC output voltage 302 .
FIG. 3 shows the DC power source 301 connected to four power MOSFET switches 311 - 314 in an H-bridge configuration. These power MOSFETS include body diodes in anti-parallel orientation. The body diodes are not explicitly illustrated in FIG. 3 but are shown above in FIG. 1 . Inductors L 1 321 , L 2 322 and capacitor C 1 323 are also shown in FIG. 3 . The inductors L 1 and L 2 and the capacitor C 1 may serve to smooth the output of the four MOSFET switches, which is inherently rough. In other words, the inductors and capacitor may serve as a third-order filter that dampens the output of the power MOSFETs into a smoother sine waveform. This smoother sine waveform may be fed to the alternating current voltage source 302 . This voltage source 302 may be considered to be an AC voltage to the power grid.
In embodiments, the MOSFETS in FIG. 3 may be opened and closed in a pattern such that they serve as a pulse-width modulated bridge. In operation, depending upon the positions of the MOSFETS, the bridge may be producing one of three outputs: positive direct current, negative direct current, and zero direct current. The speed with which the MOSFETS are opened and closed may be increased in certain embodiments such that the size of the inductors may be preferably minimized or reduced.
Brief periods may exist where two switches are both carrying the full current and blocking the full voltage causing a spike of power for, perhaps, nanoseconds. On average, these spikes add up to a significant amount of power loss. Thus, preferred embodiments provide switching fast without dissipating much power.
The body diodes of the MOSFETS 311 - 314 serve to dissipate current from the inductor L 1 in instances when Q 1 311 and Q 2 313 are turned off. However, these body diodes may have poor reverse recovery charge characteristics. In embodiments, when these body diodes conduct the reverse recovery event may be reduced or eliminated as these reverse recovery events can constitute large portions of switching loses.
The sensing circuit 330 may act to detect the current that is flowing through the inductors. In embodiments, the value of R s may be small, perhaps 20 m ohms. As shown, the sensing circuit may also include an op-amp or gain amplifier R f 340 , which serves to provide a voltage indicative of the current flowing through the inductors. Two signals, which represent the top and bottom of the voltage, may then be fed to comparators 351 and 352 . Signals B b and B t fed into these comparators may represent the boundaries for the top and bottom of the voltage. When boundaries are crossed, flip flops may be set and reset to manage the MOSFET switches and the current flowing through the inductors. The signals Q 354 and Q 353 may be used to determine if the flip flops are set or reset.
In FIG. 3 the additional gates show how signals P c and P c , which represent the polarity of the current, may be used to control switching signals q 1 -q 2 382 and q 3 -q 4 372 . These switching signals 382 and 383 may be fed to gate drive circuits 385 and 375 . So instructed, the gate drive circuits may then serve to fire the applicable gate node of one or more of the switches 311 - 314 . When the voltage is positive, P c is set to one and the current P c may be zero. In embodiments, the duty-cycle boundaries may be set such that when the diodes discharge they may do so without spiking or without heavy noise anomalies.
FIG. 4 shows top and bottom duty-cycle boundaries for almost an entire switching cycle. As can be seen the cycle can last less than 0.02 seconds and the voltage may be positive and ranging from above 3.5 volts to below 1.5 volts. These ranges are exemplary and may vary depending upon the use and particular circuit involved. Here, the voltages have been offset such that 2.4 volts represents zero amps.
In embodiments, varying the top boundaries can serve to determine how much power is delivered to the grid—with the larger the area under the boundary the more power may be delivered. The bottom boundaries may be near zero amps, but are more likely offset in order to clear out charge in the body diodes or other circuit elements providing reverse recovery charges. The cycle speed in this and other embodiments may be on the order to 200 KHz.
FIG. 5 illustrates the current output of a power controller circuit controlled consistent with embodiments of the invention. Notably, the boundary parameters from which this current wave was taken employs a variable upper boundary and a fixed lower boundary, such as the boundaries shown in FIG. 4 .
Feedback controllers may be employed to provide current outputs consistent with FIG. 5 . These controllers may serve to correct for errors such as start up noise 510 , and for zero-cross distortions 500 , both of which are shown in FIG. 5 . In addition to using the feedback circuit to settle the current, all four switches may be pulsed near the zero-crossing to facilitate pushing through that crossing. This pulsing may occur 300 microseconds before and after the zero-crossing. This pulse timing may be selected based upon a percentage of the cycle time. For example, with a 60 Hz cycle waveform, a 300 microsecond lead and lag can represent about 1.8% of a line cycle. In preferred embodiments, this pulsing may have a small impact on efficiency and may have the beneficial effect of reducing distortion at the zero-crossing. In embodiments, the pulsing may occur at different times and for different durations as well. Still further, the pre-crossing pulse may begin 200 microseconds before zero-crossing and the post-crossing pulse may end 350 microseconds after zero-crossing. other pulse times and percentages of cycle time may be employed as well in embodiments.
FIG. 6 shows the corresponding current for the boundaries of FIG. 4 , where the current is oscillating between two boundaries at a rate approximately equal to 200 KHz. In FIG. 6 , an offset of 0.25 A was employed and peak current was 1.0 A.
FIG. 7 shows top and bottom boundaries where the bottom boundary has a sinusoidal aspect instead of being a constant. In this embodiment the bottom boundary begins and ends at 0 . 0 and then moves to −0.5 during a cycle. By moving off of zero, clearing out the body diode charge may be accomplished.
As shown in FIG. 7 , the top boundary may be defined by the wave
B top =2.4424+2 sin(ω t ) P c +O
and the bottom boundary may be defined by the wave
B bottom =2.4424+2 sin(ω t ) P c −O
As can be seen, these boundary equations may be shifted by a constant—here 2.4424. This shift constant may serve to provide that current sense amplifiers substantially always or always output positive values, even when the current becomes negative. Accordingly, in embodiments the output of a current sense amplifier may include the sum of a shift constant and the value of the actual sensed current.
The upper boundary and the lower boundary can serve to have the effect of reducing switching loss by clearing out reverse recovery charges. In embodiments, variable bottom boundaries may provide for a much smoother transition from positive current to negative current. A smooth transition is shown in FIG. 8 . Comparatively, because of the larger area, constant duty-cycle boundaries can serve to ensure that charges are cleared out more thoroughly than with variable duty-cycle boundaries. This more complete clearing of electrical charge can provide for more efficient switching. Comparatively, variable duty-cycle boundaries may provide for smoother output waveforms but not as efficient switching and associated losses.
Embodiments may also include duty-cycle boundaries setting other thresholds. These thresholds can include constant stepped boundaries, where the steps increase or decrease in fixed or variable amounts and the plateaus of the steps may remain constant as well as variable stepped boundaries, where the steps increase or decrease in fixed or variable amounts and the plateaus of the steps may themselves be curved or variable. Still further, the steps in these or other embodiments may be variable and may or may not be uniform. Other modifications to the boundaries, and the thresholds they set, are also possible.
FIG. 8 shows current output where the offset may be adjusted to a constant value of 0.25 and the output peak current is set to 1 A, which are the boundaries shown in FIG. 7 . As can be seen, zero-cross distortion 800 and startup distortion 810 may also be adjusted and managed by offsets in the values of the boundaries and adjustments in the peak current settings. Notably, embodiments need not employ feedback controllers to function. The simulation represented in FIG. 8 does not employ such a controller.
FIG. 9 shows a portion of an exemplary circuit embodying the invention. In FIG. 9 , op-amp feedback circuit generates an error signal representing the difference between the desired current and the actual current. Embodiments may or may not include this secondary global feedback circuit as the op-amps U 5 and U 7 also serve to provide feedback correction in the circuit. The Q err signal signal may then be fed to two parallel op-amps U 4 and U 3 to implement the boundaries. By using a feedback circuit, discrepancies between desired current and actual currents can be resolved and converged.
Alternatively, the duty-cycle boundaries may be implemented with software and digital converters. Software may be limited because of sampling rates. Nevertheless, if a controller can be configured as such, it may be more advantageous because of price savings associated with software.
In FIG. 9 , the op-amps serve as clamps, where the lower op-amp lets an error pass though unless it is negative, in which case the error is set to negative 0.5 amps. The top op-amp may be providing the top boundary. ILTR+ and ILTR− provide signals that represent the top and bottom boundaries. These signals may be sent to op-amps U 5 and U 7 . Thus, the feedback controller is an extension of the duty-cycle boundary features and may or may not be used in embodiments.
FIG. 10 shows a power circuit inverter including a feedback circuit as may also be used in embodiments. This power circuit includes high-side switches 1110 and 1014 , low side switches 1012 and 1016 , series inductors 1020 and 1021 , capacitor 1070 and split phase voltage system 1081 and 1082 . Also shown in FIG. 10 are low-side bus reference sense resistors 1050 and 1051 . By using these sense resistors current may be sensed from the common of the DC supply rather than or in addition to sensing form the filter inductors as discussed above. By placing the sensors on the low side of the DC supply, control circuitry may be referenced from the bus. Comparatively, if current is sensed from the filter inductors then high-side or floating sense resistors are preferably used. In embodiments, low-side sensing may be preferred as high side sensing may invoke unwanted noise or require costly components to avoid, especially when small amounts of voltage, on the order of 20 mV or so are provided by the high-side sense resistors from the node that oscillates in the range of 0 VDC to 400 V DC. Nevertheless, embodiments may include high-side buses in their designs. Thus, low-side bus reference sensing may be preferred in embodiments.
The use of sense resistors 1050 and 1051 in each of the MOSFET legs of the dc-ac output stage of FIG. 10 shows that embodiments may include these low-side sense resisters when a common is readily accessible near the switches. As noted, the inductors 1020 and 1022 of the embodiment of FIG. 10 are effectively in series and are coupled to a split-phase voltage system 1081 and 1082 . For purposes of circuit analysis, this split-phase system may be considered a single source of double the voltage value.
FIG. 11 shows that the low-side sense resistor signals may be amplified and multiplexed so as to create a signal i sns representing the absolute value of the line current. This signal may then be compared with a commanded boundary current to control switching logic of the switches. The circuit of FIG. 12 shows one such circuit as to how the i sns signal may be used in controlling switching logic.
In FIG. 11 , two differential amplifiers 113 and 1140 are shown and coupled to provide gain to the small sense resistor voltages of sense resisters 1050 and 1051 . These sense resistors, i.e., leg resistors, are shown and may be referenced to the bus common. The differential amplifier output may be multiplexed by the analog switch/multiplexer 1110 , which is shown toggling between two outputs. The multiplexing may be controlled by logic signals P 1120 and P 1121 . As shown, this control and multiplexing produces an i sns value 1130 that represents the absolute value of the line current in the switching block. In use, with a positive current at switch 1016 , a proportional voltage may be produced across sensor 1051 . This voltage may then be referenced into an applicable current. By alternating between leg resistors 1050 and 1051 the current in the switch block can be synthesized.
FIG. 12 shows embodiments for making the comparison to generate the same switching signals. FIG. 12 uses a set reset flip flop with a truth table. Shown in FIG. 12 is that the sensed current may be shifted up in embodiments (0.5 as shown in this figure) to account for the lower bound (in this circuit, the sensed current +0.5 is compared to zero volts). The upper bound then also has to be shifted by +0.5 to account for the negative lower bound, and then another 0.5 to account for the shift in the sensed value. The comparators produce the switching signal which is set by the SR flip-flop. The switch logic device 1220 may then produce the appropriate switch gating signals consistent with the truth table shown.
FIG. 12 provides a circuit topology showing how a sensed current i sns may be compared to a command current in order to control switch block logic in embodiments. The sensed current i sns may originate in circuits similar to those shown above as well as in other circuit topologies. In the topology of FIG. 12 , digital to analog converter 1250 may receive a signal from the processor and blocks. This signal may represent the command current 1290 , which is shown as 2i*|1. This command current may be fed to comparator 1270 , which may also receive a sensed current signal i sns . This sensed current signal may be increased and may be offset by 0.5 to accommodate and provide for the body drain discussed above. The i sns signal may also be fed into comparator 1271 in order to be compared to ground. The outputs of the comparators 1270 and 1271 may be fed to the set-reset flip flop 1230 . This flip flop may itself be coupled to a switch logic device 1220 , which also has logic signal P as an input. The switch logic device may generate output drive signals for switches q oc1 -q oc4 depending upon the logic state of P and Q. The flip flop truth table 1240 provides the logical output forth e logic device 1220 depending upon the inputs.
In operation, when the comparators detect that the command current threshold or the low side thresholds are crossed, signals may be sent to the SR flip flop 1230 to provide the needed logic for controlling the switches by the switch logic device. As upper threshold are met, alternate switches may be thrown to reverse the current and maintain it within the thresholds. Likewise, when the bottom threshold is met, the switch logic may be reversed such that current will rise against towards the upper threshold. This containment between the thresholds, while also crossing a zero-volt setting can serve to reduce body diode losses. Still further, in embodiments, rather than using a fixed 0.5 adjustment to the i sns current, a variable benchmark may be used as well. This variable benchmark may serve to smooth zero-transition noise as the current and voltage cycle from positive to negative.
In further embodiments, the boundary references, comparison, and subsequent gating control may also be performed by software. The software may sample the applicable voltage sensor, determine the applicable current, compare that current to a threshold and generate signal for use by a switching gating control. When sampling rates are high, software may not be preferred as it may not be able to render signals at that speed. However, when cycle rates are lower, software comparators may be preferred to simplify the circuit design.
FIG. 13 provides features or processes as may be employed with embodiments. These features and processes may be employed as described and in variants as well. The features and processes may be performed in the presented order, in different orders, and with more or less than the features and processes provided. In other words, some features or processes may be added and others may be skipped or used elsewhere in embodiments.
As can be seen in FIG. 13 , embodiments may include generating a command signal for use in instructing or controlling inverter switch control. The inverter switch control may be consistent with discussions above, including using the logic tables provided in FIG. 12 and implicitly provided in FIG. 3 .
As can also be seen in FIG. 13 , a process in embodiments may also include generating a sensed current signal as shown at 1320 , establishing an upper voltage boundary, as shown at 1330 , and establishing a lower voltage boundary, as shown at 1340 . Consistent with discussions above, the upper voltage boundary may be a constant value or a variable value. Likewise, the lower voltage boundary may also be a constant value or a variable value.
As shown in FIG. 4 , as current alternates back and forth, the upper and lower voltage boundaries may switch from being a variable threshold to being a constant threshold. The variables used for these duty-cycle boundaries, may include the formulas identified and described above. For example, these can include the formulas shown in FIG. 7 , as well as those identified in the text above. Other formulas may also be used.
In embodiments, as shown in FIG. 13 , the lower voltage boundary may be offset such that it falls below and becomes negative for approximately half a cycle. This offset may be a constant, as well as a variable. In preferred embodiments the offset will be a constant value. Likewise, the upper value may also be offset opposite to and in response to the offset for the lower boundary. By creating equal and opposite duty-cycle boundary offsets the output currents can remain within expected values.
As explained at 1350 , because the current is swinging between positive and negative values, the offsets may be considered to apply within each cycle. In other words when the measure voltage is negative, the lower boundary may be a constant, and may be offset by another constant value. Conversely, when the voltage swings positive and the current is negative, that upper boundary may now be considered to be a constant and the offset also a constant value. In embodiments the absolute values may be considered when determining and establishing offsets.
As explained above, the offsets and the boundaries may be set such that inverter switching losses may be minimized. In embodiments, resident voltage charges associated with reverse recovery charges, may dissipate or be reduced through the introduction of switching delays, and/or through the use of certain switch timing.
As shown at 1370 , the sensed current signal may then be compared to the established voltage boundaries when the upper boundary is applicable, and to an established lower boundary, when the lower boundary is applicable. This determination is shown at 1380 .
As shown at 1390 , if the determination reveals that the signal falls within the applicable boundary, then one or more powertrain switches may be triggered in the circuit. Conversely, if the sensed current signal falls outside of the applicable boundary, then no triggering signals for the MOSFET or other powertrain switches may be sent. As shown in FIG. 13 , the process may begin again at 1310 or remain in a sensing loop at 1395 . Embodiments may contain other steps or features as well.
FIG. 14 shows topology of a power converter 1400 comprising a step-down converter circuit 1420 of switching type having an input port 1415 to couple to a supply voltage 1410 and having an output port 1425 to provide an output voltage at a magnitude that is lower than a magnitude of the supply voltage. The converter also comprises a control circuit 1465 configured to receive a feedback signal and regulate the magnitude of the output voltage in response thereto and a DC/AC converter circuit 1430 of switching type having a primary side 1455 and a secondary side 1460 , the primary side having an input port 1435 coupled to the output port 1425 of the step-down converter circuit 1420 . The secondary side 1460 also has an output port to provide an AC output voltage. Still further, the converter also comprises a rectifier circuit 1445 having an input port 1440 and an output port 1450 , the input port being coupled to the secondary side 1460 of the DC/AC converter circuit 1430 , the output port 1450 supplying a DC voltage and a feedback circuit 1470 to generate the feedback signal in response to the output port of the rectifier circuit.
The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms “a,” “an” and “the” are intended to include plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specific the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operation, elements, components, and/or groups thereof.
Embodiments may be implemented as a computer process, a computing system or as an article of manufacture such as a computer program product of computer readable media. The computer program product may be a computer storage medium readable by a computer system and encoding a computer program instructions for executing a computer process.
The corresponding structures, material, acts, and equivalents of all means or steps plus function elements in the claims below are intended to include any structure, material or act for performing the function in combination with other claimed elements are specifically claimed. The description of the present invention has been presented for purposes of illustration and description, but is not intended to be exhaustive or limited to the invention in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill without departing from the scope and spirit of the invention. The embodiment was chosen and described in order to best explain the principles of the invention and the practical application, and to enable others of ordinary skill in the art to understand the invention for embodiments with various modifications as are suited to the particular use contemplated.
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Power conversion methods, systems, articles of manufacture, and devices are provided. The power conversion may include converting between direct current and alternating current wherein switching losses associated with latent electrical charges are reduced. Current sensing may be low-side bus reference. Solid-state implementations, code implementations, and mixed implementations are provided.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims priority to U.S. Provisional Application Ser. No. 61/838,952 filed on Jun. 25, 2014, the contents of which are hereby incorporated in their entirety.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable.
NAMES OF PARTIES TO A JOINT RESEARCH AGREEMENT
Not Applicable
REFERENCE TO SEQUENCE LISTING, A TABLE, OR A COMPUTER PROGRAM LISTING APPENDIX SUBMITTED ON A COMPACT DISC AND INCORPORATION-BY-REFERENCE OF THE MATERIAL
Not Applicable.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a substrate for manufacturing customizable interlocked web products. More particularly, the invention relates to an apparatus and method for making bracelets and other products which are composed of elastic bands and may be customized by being interlinked in different patterns and by attaching charms to them.
2. Background Information
Ornamental bands such as bracelets, anklets and necklaces made of interlinked elastic materials such as rubber bands and other related materials are popular accessories that people wear to represent school spirit, group associations and other symbolic forms of expressions. Bands can be worn on the arms and also on other areas of the body such as on the ankles. These bands are very difficult to manufacture by hand, as skill in the art and a great quantity of time is required, which many people do not have.
Finding ready-made elastic jewelry products customized to an individual's needs can be very difficult, and also very expensive, as the need to purchase more jewelry increases.
It is therefore desirable to provide a device which can easilyist any person wishing to sevl lined bands to form a braceletther device.
It is also desirable to provide an easy method of creating such interlinked bands performable by anyone regardless of knowledge or skill.
It is also desirable to provide a device which allows an easy method of creating customizable elastic jewelry products.
BRIEF SUMMARY OF THE INVENTION
The principles of the invention provide a device and method which allows the end user to conveniently cross link elastic materials such as rubber bands by providing an easy to use pin wheel guiding platform, and an interlocking utensil.
An object of the invention is to provide an easy method of making a customizable elastic jewelry products and one that is more economical for the average end user.
Another object of the invention is to provide a new and unique type of jewelry making device which allows the user to make customizable products which may not be available on the market.
In one embodiment, a platform has a plurality of substrate stations. Each substrate stations have a pair of upwardly protruding, cylindrical stems. The stems each have a bulbous cap that may protrude more in one direction, such as away from each stem. The plurality of substrate stations may be arranged in one or more rows, and may be numbered and/or provided a beginning and end point for each row. The stems may protrude from a pedestal, or other base-like structure at the bottom of the substrate station.
In use, elastic bands may be placed on each pin pair of each substrate station and subsequently interlinked with one another to produce a bracelet, necklace or other woven product. A utensil may be used to assist in interlinking the bands. The bands may be interlinked in a variety of different patterns. Charms or other objects may also be used to ornament the web product.
In another embodiment, a platform for weaving interlinking elastic bands comprises a platform having a top surface and a plurality of stations on the top surface. The stations are aligned into one or more rows.
Each of the stations comprises a pedestal, two stems extending upward from the pedestal, each of the stems having a crown.
In one embodiment, the stations are removably attached to the platform. The platform may further comprise one or more storage wells, and/or a clip for holding a weaving utensil and a weaving utensil.
In another embodiment, the platform is circular. The crowns of the stems may be spherical or oblong. If they are oblong, they may face away from each other and/or be perpendicular to the direction of the rows.
In another embodiment, the stations are removably attached to the platform and the platform may include one or more storage wells.
Also disclosed is a method for weaving interlinking bands comprising the steps of a) stretching an elastic band between two or more stems of two or more stations of a platform having a plurality of stations aligned into one or more rows such that tension created by the stretching holds the band in place suspended between the two or more stems, b) stretching another elastic band between two or more stems of two or more stations of a platform having a plurality of stations aligned into one or more rows such that tension created by the stretching holds the band in place suspended between the two or more stems, c) pulling a portion of one of the elastic bands through the elastic band by means of a weaving utensil, d) attaching the portion of the elastic band pulled through another elastic band to at least one stem such that tension caused by stretching the elastic band holds the portion in place about the at least one stem; and repeating steps a-d to provide a plurality of interwoven elastic bands.
The method for weaving interlinking elastic bands may use stems includes a spherical or oblong crowns, which may be perpendicular to the rows.
These and other objects and advantages of the present invention will become apparent from a reading of the attached specification and appended claims. 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 features of the invention that will be described hereinafter and which will form the subject matter of the claims appended hereto.
BRIEF DESCRIPTION OF THE DRAWINGS
A more complete understanding of the present invention, and the attendant advantages and features thereof, will be more readily understood by reference to the following detailed description when considered in conjunction with the accompanying drawings wherein:
FIG. 1 is a perspective view of a circular platform for weaving interlinking elastic bands in accordance with the principles of the invention;
FIG. 2 is a perspective view of a station in accordance with the principles of the invention;
FIG. 3 is top view of the circular platform for weaving interlinking bands in accordance with the principles of the invention;
FIG. 4 is a side view of a removably attachable station use with removable stations in accordance with the principles of the invention;
FIG. 5 is an alternative top view of a circular platform having a plurality of sockets for removable attachment of stations in accordance with the principles of the invention;
FIG. 6 is a cross-sectional side view of a circular platform having a plurality of sockets for removable attachment of stations in accordance with the principles of the invention;
FIG. 7 is an enlarged view of a portion of a cross-sectional side view of a circular platform having a plurality of sockets for removable attachment of stations in accordance with the principles of the invention.
DETAILED DESCRIPTION
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.
FIG. 1 shows a circular platform for weaving interlinking bands 10 in accordance with the principles of the invention. Platform 10 is comprised of a base 12 in the shape of a flattened cylinder. The base 12 has a top surface. The top surface 14 may include two storage wells 20 that may be used to store elastic bands or other materials. Top surface 14 may also include a clip 22 for securing a weaving utensil 18 to the top surface 14 when not in use. In this embodiment, the weaving utensil 18 may be elongate having a handle 19 on one end and a weaving hook 17 on the opposite end.
A large portion of top surface 14 may be covered by a plurality of stations 16 . Each station 16 may be designed to accommodate one or more elastic bands during the weaving process. The stations 16 may be arranged in one or more rows.
FIG. 2 is an enlarged view of a station 16 . Stations 16 may have a pedestal 30 serving as a base for the station 16 . Two stems 32 may extend upward from the pedestal 30 . Each of stems 32 may have a crown 34 at the top. Each crown 34 may be spherical, oblong, parallelepiped or other shape. The crown may include a distal end 36 extending at least partially perpendicular to the stem 32 . In this embodiment, the distal ends 36 of the oblong “egg-shaped” crowns 34 extend away from each other, may be substantially perpendicular to the stems 32 and may have rounded edges. In other embodiments, it may be desirable for the distal ends 36 of the crowns 34 to extend in the same direction, perpendicular to each other, or at an acute or obtuse angle relative to each other.
Stems 32 may be substantially cylindrical and rigid. It is generally desirable for the stems 32 to be rigid in order to securely retain elastic bands in a semi-extended form, and held in place by tension resulting from the elastic bands being stretched over two or more stems. In some embodiments, it may not be desirable for stems 32 to be completely rigid. It may also be desirable for stems 32 to have an oval or polygonal cross-section instead of being cylindrical. Similarly, in this embodiment, pedestal 30 is cylindrical. It may be desirable for pedestal 30 to be more prismatic or rectangular. Optionally, it may be desirable for the pedestal 30 to be rounded, or have a hemispherical shape. This embodiment of a station 16 has bilateral symmetry. Stations may optionally have other types of symmetry or none at all.
FIG. 3 shows a top view of the circular platform 10 . It may be seen that top surface 14 is substantially bilaterally symmetric. As a result, wells 20 may be symmetrical. The stations 16 may be generally aligned in rows as shown here. An outer row 40 , central row 42 and inner row 40 . are substantially parallel to each other. The top surface 14 may include numbering in order to designate each individual substrate station 16 for ease of use.
FIG. 4 shows a side view of a removably attachable station 50 , designed as a unitary manufactured piece for integration with a separately manufactured platform shown in FIGS. 5-7 . Removably attachable station 50 includes a pedestal 52 and two stems 54 . As with substrate station 16 in FIGS. 1-3 , pedestal 52 is a flattened cylinder. Stems 54 are topped by crowns 56 , each having an oblong shape. Station 50 includes a bottom portion 60 having two downwardly protruding fingers 62 each having a tab 64 that snaps into place when the station 50 is attached to a platform.
FIG. 5 shows a circular platform 70 having a plurality of substrate station sockets 76 arranged in three rows on the top surface 74 of platform 70 . Storage wells 78 may be used to hold objects while clamp 80 may be used to hold a weaving utensil (not shown). A station 52 , as shown in FIG. 4 may be snapped into each of the station sockets 76 . FIG. 6 shows a cross-sectional view of platform 70 along axis A and FIG. 7 shows an enlarged view of a portion of FIG. 6 . In both FIGS. 6 and 7 it may be seen that wells 78 and sockets 76 are cavities within platform 70 . By providing removable attachment of stations into sockets on a platform, the weaving platform in accordance with the principles of the invention allows simple repair and/or replacement of stations. Because the stems are relatively thin and are exposed to forces imparted by elastic bands stretched over them, they may be prone to breaking
The platforms in the embodiments are circular having three rows. Optionally, the platforms may be rectangular, ovoid, or any other shape and may have only one row, or may have more than three rows running parallel.
In use, elastic bands are stretched over two or more stems, either on the same station or on neighboring stations. A weaving utensil may then be used to pull a portion of one of the elastic bands through another band. The stretched portion may then be attached to another stem. In this manner, a Brunnion link is formed, connecting the two bands. This process is continued for many elastic bands over many stems to form a long chain of elastic bands all interconnected by means of Brunnion links.
Whereas, the present invention has been described in relation to the drawings attached hereto, it should be understood that other and further modifications, apart from those shown or suggested herein, may be made within the spirit and scope of this invention. Descriptions of the embodiments shown in the drawings should not be construed as limiting or defining the ordinary and plain meanings of the terms of the claims unless such is explicitly indicated.
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.
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A platform for linking elastic bands together to form bracelets, anklets, necklaces and jewelry products has a circular platform having a plurality of substrate stations for retaining elastic bands in a semistretched configuration. An interlinking utensil allows a user to make cross-linked jewelry products which can be worn around a wrist or other area of the body. The substrate stations may be aligned in one or more rows.
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TECHNICAL FIELD
This invention relates to an AC/DC converter.
Background Of The Invention
In an advanced single phase, sine-wave voltage, high frequency power distribution system, for example, such as that used in a 20 kHz Space Station Primary Electrical Power Distribution System, power conversion from AC to DC is required. Some of the basic requirements for this conversion are:
1. High efficiency
2. Light weight and small volume
3. Regulated output voltage
4. Close to unity input power factor
5. Distortion-less input current
6. Soft-starting (low input surge current)
7. Low EMI, and
8. High reliability
There are a number of conventional approaches to the design of AC/DC converters. The most common approaches are briefly discussed below:
Link AC/DC Converters
In this type of converter, the AC output voltage is first converted into unregulated DC voltage. The unregulated voltage is then converted to regulated DC voltage by using a known DC/DC converter topology. To meet the input requirements (distortion-less input current and close to unity power factor) and output requirements (ripple free constant DC voltage), link converters employ several conversion stages and have a high count of power components. Therefore, this type of converter has a low efficiency and reliability and a high weight and volume.
Switch Mode Rectifier (SMR)
The SMR circuit has been used in low frequency applications for AC/DC conversion with a good quality input current waveform. In this approach an active filter is used at the output of the diode rectifier to reduce the size of input filter which is very bulky at lower frequencies. The active filter used in a SMR is essentially a boost or buck converter whose switching frequency is approximately 500 times greater than the input supply frequency, to eliminate the lower order harmonics from the input current. Therefore, this circuit in a high frequency power distribution system, where the distribution frequency is in the order of 20 kHz, would be very inefficient due to very high switching losses of the buck or boost converter at these elevated switching frequencies. In addition, this circuit has all the aforementioned drawbacks of any link AC/DC converter.
Controlled Rectifier
In this rectifier the output DC voltage is controlled by controlling the delay angle of the thyristors. This circuit generates large current harmonics in the supply lines, has a poor input power factor over the full range of voltage control, and has high EMI.
None of the above approaches entirely satisfy the main design objectives of AC/DC converters for high frequency power distribution system in, for example, space applications.
SUMMARY OF THE INVENTION
According to the present invention there is provided an AC to DC converter comprising:
(a) an input transformer for connection to a single phase, high frequency, sinusoidal wave form, AC voltage source, the transformer, in operation, providing a matching output voltage for, and isolating from, the AC voltage source,
(b) a resonant network for converting the single phase, high frequency, sinusoidal wave form, AC voltage to a sinusoidal, high frequency bi-directional current output,
(c) a current controller connected in parallel to the resonant network to receive the sinusoidal high frequency current output therefrom and provide the desired output current from the converter.
(d) a diode rectifier connected in parallel with the current controller, and for converting the bi-directional current into a unidirectional current output, and
(e) an output filter connected to the rectifier to provide an essentially ripple free, substantially constant voltage, DC output.
The resonant network may be connected to receive the output matching voltage.
The resonant network may be for connection to the AC voltage source and for passing the high frequency current output, generated by the resonant network, to the transformer.
The input transformer may have a primary and a secondary winding, and the resonant network may comprise two capacitors, one capacitor being connected in series with the primary winding of the transformer, and the other capacitor being connected in series with the secondary winding of the transformer.
The resonant network may comprise an inductor and a capacitor, and the capacitor may be connected in series to the output of the inductor.
The resonant network may further comprise a capacitor connected in parallel with the input transformer.
The current controller may be a bi-directional switch.
The bi-directional switch may be a thyristorized bi-directional switch.
The output filter may be a capacitor.
The output filter may be a π network comprising a capacitor, an inductor and a capacitor.
BRIEF DESCRIPTION OF THE DRAWING
In the accompanying drawings which illustrate, by way of example, embodiments of the present invention,
FIG. 1 is a schematic diagram of an AC to DC converter,
FIG. 2 is one form of a resonant circuit that may be used in the converter shown in FIG. 1,
FIG. 3 shows various wave forms generated in the converter shown in FIG. 2,
FIG. 4 shows the normalized output voltage of the converter shown in FIG. 2 as a function of the firing angle of the current controller,
FIG. 5 is a different form of resonant circuit that may be used in the converter shown in FIG. 1,
FIG. 6 shows the operating principle of the circuit shown in FIG. 5,
FIG. 7 shows the control of the output voltage, of the circuit shown in FIG. 5, as a function of angle α,
FIG. 8 is yet another different form of resonant circuit to that shown in FIG. 1,
FIG. 9 shows the operating principle of the circuit shown in FIG. 8, and
FIG. 10 is a form resonant circuit to that shown in FIG. 1 having two outputs.
DETAILED DESCRIPTION
In FIG. 1 there is shown an AC to DC converter comprising:
(a) an input transformer, generally designated 1, for connection to a single phase, high frequency, sinusoidal wave form, AC voltage source 2, the transformer 1, in operation, providing an output matching voltage for, and isolating, the AC voltage source 2,
(b) a resonant network, generally designated 4, for converting the single phase, high frequency, sinusoidal wave form AC voltage to a sinusoidal, high frequency bi-directional current output,
(c) a current controller, generally designated 6, connected in parallel to the resonant network 4 to receive the sinusoidal high frequency current output therefrom and provide the desired output current from the converter,
(d) a diode rectifier, generally designated 8, connected in parallel with the current controller 6 and for converting the bi-directional current into a unidirectional current output, and
(e) an output filter, generally designated 10, connected to the rectifier 8 to provide an essentially ripple free, substantially constant voltage, DC output to a load 11.
As shown in FIG. 2, in some embodiments of the present invention the resonant network comprises an inductor 16 and a capacitor 18, with the capacitor 18 connected in series to the output of the inductor 16.
The current controller 6 is a thyristorized, bi-directional switch comprising two anti-parallel, thyristor switches 20 and 22.
The diode rectifier comprises four diodes 24 to 27.
The output filter 10 comprises a capacitor.
In operation a single phase, high frequency, sinusoidal wave form, AC voltage from source 2 is applied to the primary winding 12 of the transformer 1 and the secondary winding 14 providing a matching output voltage for, and isolates the remaining circuit from, the source 2.
The matching output from the secondary winding 14 of the transformer 1 is fed to the inductor 16. Both of the series components of the resonant network 4, that is, the inductor 16 and the capacitor 18 are tuned closely to the operating frequency of the input from the single phase, high frequency, sinusoidal wave form, AC voltage source 2, so that these components offer close to zero impedance for fundamental current and very high impedance to harmonic currents to keep the total harmonic current distortion of the input current to a minimum. This also ensures an input power factor that is close to unity.
The current controller 6 controls the amount of output current from the resonant network 4 that is needed to be rectified, to achieve the output voltage and current desired at the load 11.
The output filter 10 smooths the ripples generated by the diode rectifier 8 and provides a constant voltage to the load 11.
A description of the operation of the AC/DC converter shown in FIG. 2 will now be given with reference to FIG. 3.
At the position of the cycle where w o t=0, diodes 24 and 27 are conducting and the input resonant current i i is charging the output capacitor 10. This input current keeps charging the capacitor 10 until w o t=α, where the switch 20 is triggered. At this point, the input current is instantaneously transferred to the switch 20 from the diode rectifier 8 to end the charging period of the output capacitor 10. At w o t=π-φ, the resonating input current, flowing through switch 20, goes to zero, thereby extinguishing its conduction. At this instant, diodes 25 and 26 become forward biased and carry the negative input resonant current. The rectification action of the diodes 25 and 26 changes the direction of this current at the output and starts the charging of the capacitor 10. At w o t=π+α, the current flowing through diodes 25 and 26 is transferred to switch 22 by triggering it to end the charging period. Switch 22 conducts until the input resonant current flowing through it goes to zero. At this point, diodes 24 and 27 start to conduct once again and a new cycle begins.
Referring now to FIGS. 2 and 4, in this type of converter the control of the output voltage is provided by controlling the firing angle (α) of the current controller 6. FIG. 4 shows a typical curve for the output voltage of this type of converter as a function of the angle.
At α=180°, neither of the thyristor switches 20 and 22 of the current controller. 6 are conducting, and energy stored in the components 16 and 18 of the resonant network 4 is limited by the output load. For any other value of the α≠180°, excess energy is stored in the components 16 and 18 of the resonant network 4 for a duration of (π-α) in each half cycle in which either one of the thyristor switches 20 and 22 is conducting. This excess energy results from the fact that the equivalent quality factor of the resonant network 4 has increased due to the partial short circuiting of the output load 11. The excess energy stored in the components 16 and 18 of the resonant network 4 is released to the output load 11 to increase the output voltage level during the interval of each half cycle.
As seen in FIG. 4, the output voltage of the converter increases as the firing angle (α) decreases. An operating point, therefore, is chosen for α≠180° to provide the control of output voltage (V o ).
In FIGS. 5 to 6, similar parts to those shown in FIG. 1 and 2 are designated by the same reference numerals and the previous description is relied upon to describe them. However, as will be seen, while the components and their individual functions may be the same as those shown in FIG. 1 and 2, these components function collectively on different principles thereto.
In FIG. 5, the resonant circuit 4 further comprises a capacitor 28 connected in parallel with the input transformer 1. In operation a single phase, high frequency, sinusoidal wave form, AC voltage from source 2 is applied to the primary winding 12 of the transformer 1 and the secondary winding 14 provides a matching output voltage for, and isolates the remaining circuit, from source 2.
The components 28, 16 and 18 of the resonant circuit 4 are selected in such a way that a close to unity input power factor, and a sinusoidal AC current of near constant amplitude through components 16 and 18, under full-load to short-circuit conditions, are obtained when the matching output voltage from the secondary winding 14 of the transformer 1 is fed to the resonant circuit 4.
The current controller 6 controls the amount of output current, from the resonant circuit 4, that is needed to be rectified, to achieve the output voltage and current desired at the load 11.
The output filter 10 which consists of a capacitor 30, an inductor 32, and a capacitor 34, provides a low ripple constant output voltage to the load 11.
A description of the operation of the AC/DC converter shown in FIG. 5 will now be given with reference to FIG. 6.
At the position of the cycle where w o t=φ, diodes 24 and 27 are conducting and the input resonant current i i is charging the output capacitor 30. This input current keeps charging the capacitor 30 until w o t=φ+α, where the switch 20 is triggered. At this point, the input current is instantaneously transferred to the switch 20 from the diode rectifier 8 to end the charging period of the output capacitor 30. At w o t=π+φ, the resonating input current flowing through switch 20, goes to zero, thereby, extinguishing its conduction. At this instant, diodes 25 and 26 become forward biased and carry the negative input resonant current. The rectification action of the diodes 25 and 26 changes the direction of this current at the output and starts the charging of the capacitor 30. At w o t=φ+α+π, the current flowing through diodes 25 and 26 is transferred to switch 22 by triggering it to end the charging period. Switch 22 conducts until the input resonant current flowing through it goes to zero. At this point, diodes 24 and 27 starts to conduct once again and a new cycle begins.
Referring now to FIG. 5 and 7, in this type of converter the control of the output voltage is provided by controlling the firing angle (α) of the current controller 6. FIG. 7 shows a typical curve for the output voltage of this type of converter as a function of the angle.
At α=180°, neither of the switches 20 and 22 of the current controller 6 are conducting, all the current flowing through the resonant components 16 and 18 is rectified by the rectifier 8, thereby, producing the maximum output voltage at the load 11. As described earlier, the resonant components 28, 16 and 18 are selected in such a way that the resonating current flowing through 16 and 18 has a near constant amplitude under full-load to short-circuit conditions. For α≠180°, when either switches 20 and 22 of the current controller 6 is conducting in each half-cycle, for a duration of (π-α), a portion of the current is shunted by the current controller 6. Thereby, reducing the amount of the current at the input of the rectifier 8. This lowers the output voltage across the load 11.
As seen in FIG. 7, the output voltage of the converter, which is shown as output voltage (V o )/Rated Output voltage V R , decreases as the firing angle (α) decreases.
In FIG. 8, the resonant circuit 4 comprises the capacitors 36 and 38, capacitor 36 being connected in series with the input of the primary winding 12 of the transformer 1, and the other capacitor 38 being connected in series with the secondary winding 14 of the transformer 1.
The capacitors 36 and 38, and the transformer 1 are selected in such a way that a close-to-unity input power factor, and a sinusoidal AC current wave form of near constant amplitude through capacitor 38, under full-load to short-circuit conditions, are obtained when a single-phase, high frequency, sinusoidal wave form AC voltage from source 2 is applied to the series combination of the capacitor 36 and the primary winding 12 of the transformer 1.
The current controller 6 controls the amount of the output current, from the resonant circuit 4, that is needed to be rectified, to achieve the output voltage and current desired at the load 11.
The output filter 10 provides a low ripple constant output voltage to the load 11.
A description of the operation of the AC/DC converter shown in FIG. 8 will now be given with reference to FIG. 9.
At the position of the cycle where w o t=π/2, the resonating input current ii goes to zero and forward biases the diodes 25 and 26. The rectification action of the diodes 25 and 26 changes the direction of this current at the output and starts to charge the capacitor 10. At w o t=π/2+α, the current flowing through diodes 25 and 26 is transferred to switch 22 by triggering it to end the charging period. Switch 22 conducts until the input resonant current flowing through it goes to zero. At this point, diodes 24 and 27 start to conduct and the charging of the capacitor 10 begins. At w o t=3π/2+α, switch 20 is triggered to end the charging period. The input current i i is now carried by the switch 20. Switch 20 conducts until, the current flowing through it goes to zero. At this point, diodes 25 and 26 start to conduct once again and a new cycle begins.
The output voltage of this converter is controlled by varying the firing angle (α) in a similar manner that as shown in FIG. 7.
In FIG. 10, wherein the circuit components function in a similar manner as the corresponding components described with reference to FIG. 2, the resonant circuit 4 and the current controller 6 are on the input side to the primary winding 12 of the transformer 1.
The transformer 1 has two secondary windings 14 and 40, connected to two diode rectifiers 8 and 41 respectively, each diode rectifier comprising diodes 42, 44 and 46, 48 respectively. The diode rectifiers 8 and 41 are connected to output filters 10 and 50 respectively, which in turn are connected to loads 11 and 52 respectively.
In this manner two or more loads, such as loads 11 and 52, may be provided with regulated DC power.
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An AC/DC converter is provided, suitable for use in an advanced single phase, sine wave voltage, high frequency power distribution system, such as that used on a 20 kHz Space Station Primary Electrical Power Distribution System. The converter comprises a transformer, a resonant network, a current controler, a diode rectifier and an output filter. The voltage source is converted into a sinusoidal current source. The output of this current source is rectified by the diode rectifier and is controlled by the current controller. The controlled rectified current is then filtered by the output filter to obtain a constant voltage across the load.
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RELATED APPLICATIONS
This application is a continuation application of PCT Patent Application No. PCT/CN2013/086618, entitled “METHOD AND SYSTEM OF ADDING PUNCTUATION AND ESTABLISHING LANGUAGE MODEL” filed Nov. 6, 2013, which claims priority to Chinese Patent Application No. 201310034265.9, “METHOD, SYSTEM OF ADDING PUNCTUATION AND ESTABLISHMENT METHOD, DEVICE OF ITS LANGUAGE MODEL,” filed Jan. 29, 2013, both of which are hereby incorporated by reference in their entirety.
FIELD OF THE INVENTION
The present invention relates to the field of information processing technology, especially relates to method and system of adding punctuation and establishing language model.
BACKGROUND OF THE INVENTION
In the fields of communication and the Internet, it is needed to add punctuation for some documents short of punctuation in some application scenarios, for example, adding punctuation for speech documents.
On adding punctuation for speech documents, conventionally, there exists a kind of scheme; it is based on the mute interval when the speaker is speaking to automatically add punctuation.
Concretely, setting the threshold value of the length of mute first, if the length of mute interval when the speaker is speaking is bigger than the threshold value, adding punctuation at this place, if it is not bigger than the mentioned threshold value, not adding punctuation.
Simply relying on the interval threshold value when the speaker is speaking to add punctuation may excessively result in wrong punctuation adding, wrong pauses of sentences and so on, for example, if the speaking speed of the speaker is fast, there is no interval or the interval is so short that it is less than the threshold value, there is no punctuation added in the whole passage, if the speaking speed of the speaker is slow, approaching speaking out sentences with cruel intervals after each character, the whole passage will have a lot of punctuation, these two kinds of situations will result in wrong punctuation adding, low accuracy of punctuation adding.
Aiming at the question of low accuracy existing in the scheme of adding punctuation for speech documents based on the threshold value of the length of mute, there is a kind of improved scheme of punctuation adding based on hyphenation processing and the place of each character.
In the mentioned improved scheme, conducting hyphenation processing to the sentences in corpus first, after dividing the sentences to be processed into each character, determining the place of each character in the sentences, namely at the beginning, in the middle or at the end of sentences, and determining the situation of punctuation after each character, for example, whether there is punctuation or not and so on, establishing language model according to the place of each character in the corpus and the situation of punctuation after each character, using the established language model to add punctuation to the sentences to be processed.
In the mentioned improved scheme, it uses the place of single character in the sentences and whether there is punctuation after single character or not to establish language model, due to the information used is limited, and the information used and the status of punctuation are not closely associated, the established language model cannot extract out the real relationship between the information of sentences and the punctuation status of sentences.
Due to the language model used in the mentioned improved scheme does not extract out the real relationship between the information of sentences and the punctuation status of sentences, the accuracy of punctuation adding is low as well.
SUMMARY
The above deficiencies and other problems associated with the conventional approach of adding punctuation marks to a document are reduced or eliminated by the invention disclosed below. In some embodiments, the invention is implemented in a computer system that has one or more processors, memory and one or more modules, programs or sets of instructions stored in the memory for performing multiple functions. Instructions for performing these functions may be included in a computer program product configured for execution by one or more processors.
One aspect of the invention involves a computer-implemented method of processing information content based on a language model is performed by a computer having one or more processors and memory. The computer-implemented method includes: identifying a plurality of expressions in the information content that is queued to be processed; dividing the plurality of expressions into a plurality of characteristic units according to semantic features and predetermined characteristics associated with each of the plurality of characteristic units, each characteristic unit including a subset of the plurality of expressions and the predetermined characteristics at least including a respective integer number of expressions that are included in the characteristic unit; extracting, from the language model, a plurality of probabilities for a plurality of punctuation marks associated with each of the plurality of characteristic units; and in accordance with the extracted probabilities, associating a respective punctuation mark with each of the plurality of characteristic units included in the information content.
Another aspect of the invention involves a computer-implemented method of establishing a language model from training information content is performed by a computer having one or more processors and memory. The computer-implemented method includes: identifying, within the training information content, a plurality of expressions, wherein the plurality of expressions are separated and grouped by a plurality of punctuation marks that are located at predetermined locations in the training information content; dividing the plurality of expressions into a plurality of characteristic units according to semantic features and predetermined characteristics of each characteristic unit in the plurality of characteristic units, each characteristic unit including a respective subset of expressions; recording a respective frequency of occurrence for each of the plurality of punctuation marks that follow each of the plurality of characteristic units in the training information content; and establishing the language model based on a plurality of frequencies of occurrence of the plurality of punctuation marks, further including the recorded respective frequency of occurrence, for the plurality of punctuation marks that follow each of the plurality of characteristic units, wherein in accordance with the language model, the plurality of probabilities for the plurality of punctuation marks are used to determine a punctuation mark for a corresponding characteristic unit included in certain information content that is not yet segmented by punctuation marks.
Another aspect of the invention involves a computer system. The computer system includes memory, one or more processors, and one or more programs stored in the memory and configured for execution by the one or more processors. The one or more programs include: identifying a plurality of expressions in the information content that is queued to be processed; dividing the plurality of expressions into a plurality of characteristic units according to semantic features and predetermined characteristics associated with each of the plurality of characteristic units, each characteristic unit including a subset of the plurality of expressions and the predetermined characteristics at least including a respective integer number of expressions that are included in the characteristic unit; extracting, from the language model, a plurality of probabilities for a plurality of punctuation marks associated with each of the plurality of characteristic units; and in accordance with the extracted probabilities, associating a respective punctuation mark with each of the plurality of characteristic units included in the information content.
BRIEF DESCRIPTION OF THE DRAWINGS
The aforementioned features and advantages of the invention as well as additional features and advantages thereof will be more clearly understood hereinafter as a result of a detailed description of preferred embodiments when taken in conjunction with the drawings.
FIG. 1 is a first flowchart diagram of the method of establishing a language model used for adding punctuation according to some embodiments.
FIG. 2 is a second flowchart diagram of the method of establishing a language model used for adding punctuation according to some embodiments.
FIG. 3 is a structural diagram of the establishment device of language model used for adding punctuation according to some embodiments.
FIG. 4 is a flowchart diagram of adding punctuation method according to some embodiments.
FIG. 5 is a composition schematic diagram of adding punctuation system according to some embodiments.
FIG. 6 is a block diagram illustrative of the components of a computer system in accordance with some embodiments
Like reference numerals refer to corresponding parts throughout the several views of the drawings.
DESCRIPTION OF EMBODIMENTS
Reference will now be made in detail to embodiments, examples of which are illustrated in the accompanying drawings. In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the subject matter presented herein. But it will be apparent to one skilled in the art that the subject matter may be practiced without these specific details. In other instances, well-known methods, procedures, components, and circuits have not been described in detail so as not to unnecessarily obscure aspects of the embodiments.
FIG. 1 is the first flowchart diagram of the method of establishing a language model used for adding punctuation according to some embodiments.
As shown in FIG. 1 , this first flowchart diagram includes:
Step 101 , conducting word segmentation processing for the sentences in corpus, in which, the sentences in corpus have been added punctuation in advance.
Step 102 , according to the semantic feature of each word in the sentences after word segmentation processing, relying on the preset characteristic template, searching for the characteristic unit occurring in the mentioned corpus, recording the occurrence number of each kind of punctuation status of each characteristic unit in the mentioned corpus according to the punctuation status after each word in characteristic unit.
Step 103 , according to the occurrence number of each kind of punctuation status of each characteristic unit, determining the weight of each kind of punctuation status of each characteristic unit, establishing the language model of the correspondence of the weight of each characteristic unit and each kind of punctuation status of its own.
In which, the mentioned language model is used for providing the correspondence of the weight of each characteristic unit and each kind of punctuation status of its own in the mentioned language model according to the search request when searching out the characteristic unit from the sentences short of punctuation, so as to depend on the mentioned correspondence to add punctuation to the sentences short of punctuation.
In the Step 102 of the method shown in FIG. 1 , it can adopt Method 1, namely labeling the semantic feature and punctuation status of each word in the sentences of the mentioned corpus in advance, and then searching the characteristic unit occurring in the mentioned corpus according to the preset characteristic template, and recording the occurrence number of each kind of punctuation status of each characteristic unit. It can also adopt Method 2, namely when searching the characteristic unit occurring in corpus according to the preset characteristic template, recognizing the semantic feature of each word and the punctuation status after each word in sentences in real-time. Now, further introduce the method shown in FIG. 1 in detail with the example of realizing Step 102 by using the mentioned Method 1, referring to FIG. 2 for more information.
FIG. 2 is the second flowchart diagram of the method of establishing a language model used for adding punctuation according to some embodiments.
As is shown in FIG. 2 , the method includes:
Step 201 , conducting word segmentation processing for the sentences in corpus, in which, the sentences in corpus have been added punctuation in advance.
Step 202 , according to the semantic information of each word of the sentences after word segmentation processing in the mentioned sentences, labeling semantic feature for each of the mentioned word, according to the punctuation status information after each of the mentioned word in the mentioned sentences, labeling punctuation status for each of the mentioned word.
Step 203 , according to the mentioned semantic feature of each word, generating characteristic unit based on the preset characteristic template, the mentioned characteristic template includes the number, semantic features of the obtained words, the mentioned characteristic unit includes words and semantic features of words.
Step 204 , searching for each characteristic unit from sentences of the mentioned corpus, recording the punctuation status of the characteristic unit when each characteristic unit occurring, recording the occurrence number of each kind of punctuation status of this characteristic unit, among which, the punctuation status of the characteristic unit includes the punctuation status of each word in this characteristic unit.
Step 205 , according to the occurrence number of each kind of punctuation status of each characteristic unit, determining the weight of each kind of punctuation status of each characteristic unit, establishing the language model of the correspondence of the weight of each characteristic unit and each kind of punctuation status of its own.
In which, the mentioned language model is used for returning the correspondence of the weight of each characteristic unit and each kind of punctuation status of its own in the mentioned language model according to the calling request when searching out the characteristic unit from the sentences short of punctuation, so as to depend on the mentioned correspondence to add punctuation to the sentences short of punctuation.
In order to improve the quality of the established language model, the accuracy of the pre-added punctuation in sentences of the mentioned corpus shall be higher, it is better that all the punctuations are accurate.
In the flow shown in FIG. 2 , Step 203 and Step 204 can be realized in one process, for example, according to the preset characteristic template, extract characteristic unit from the sentences of corpus, if the extracted characteristic unit does not occurred before, it is equivalent to the generation of a new characteristic unit, and the frequency of searching out this new characteristic unit from the sentences of corpus is one.
On the basis of extracting characteristic units according to the semantic features of the words in sentences, the position information of words can be further used, the position information of the mentioned words is the relative position information of words and the current reference position, except for words, the semantic features of words, the extracted characteristic unit also includes the relative position information of words and the current reference position.
Concretely, the preset characteristic template includes the number, semantic features of the obtained words, the preset requirements needed to be satisfied by the relative positional relation of the obtained words and current reference position, extracting characteristic units from sentences based on the preset characteristic template may concretely include:
Separately using the position of each word in sentences after word segmentation processing as current reference position, determining the word whose relative positional relation between the position in the mentioned sentences and the current reference position satisfies the requirements of the mentioned characteristic template, generate the characteristic unit according to the semantic feature of the word whose mentioned relative positional relation satisfies the requirements of the mentioned characteristic template and the information of relative positional relation, the mentioned characteristic unit also includes the relative positional relation between words and the current reference position.
Through the characteristic template containing the requirements of relative positional relation, the association between words can be determined, and then the characteristic unit extracted based on the mentioned characteristic template contains the association between words, the mentioned association generally has relationship with punctuation status, therefore the language model established according to the weight relation between the mentioned characteristic unit and each kind of punctuation status can reflect the relation between the information contained in sentences and punctuation status more correctly, and then using the mentioned language model can improve the accuracy of punctuation adding.
According to the number of the obtained words required by the preset characteristic template, the preset characteristic template can include single word template and/or multi-word template.
Among which, the mentioned single word template includes obtaining the single word whose relative position relationship with the current reference position satisfies preset requirements, and semantic feature of the mentioned single word.
According to that when single word template extracts characteristic unit from sentences, respectively taking position of each word of the mentioned sentence as the mentioned current reference position, determining the single word whose relative position relationship with the current reference position satisfies the requirements of the mentioned single word characteristic template based on characteristic template of the mentioned single word, and determining characteristic unit of the single word occurring in sentence to be processed based on semantic feature of the word. The characteristic unit of the mentioned single word includes the mentioned individual word, semantic feature of the mentioned individual word and relative position relationship of the mentioned individual word with the current reference position.
The mentioned multi-word template includes obtaining multiple words whose relative position relationship with the current reference position satisfies preset requirements respectively, and semantic features of each word in the mentioned multiple words.
According to that when multi-word template extracts characteristic unit from sentences, respectively taking position of each word of the mentioned sentence as the mentioned current reference position, determining the multiple words whose relative position relationship with the current reference position satisfies requirements of the relative position relationship of the mentioned multi-word characteristic template based on the mentioned multi-word characteristic template, and determining the multi-word characteristic units occurring in sentence to be processed based on semantic features of each word of multiple words, and the mentioned multi-word characteristic units include the mentioned multiple words, semantic features of each word in mentioned multiple words and relative position relationship of the each word with the current reference position.
Among which, through modifying the requirements of the relative positional relation with current reference position in single word template, different kinds of single word template can be obtained, for example, the single word template is configured to obtain the word of current reference position and its semantic feature (may be recorded as template T00), the single word template is configured to obtain the word on the previous position of current reference position and its semantic feature (may be recorded as template T01), the single word template is configured to obtain the word on the latter position of current reference position and its semantic feature (may be recorded as template T02).
Through modifying the requirements of the relative positional relation with current reference position in multi-word template, different kinds of multi-word template can also be obtained, for example, the multi-word template is configured to obtain the word on the previous position of current reference position, the word of current reference position, the word on the latter position of current reference position and its semantic feature (may be recorded as template T05), the multi-word template is configured to obtain the word on the previous two position of current reference position, the word of the current reference position and its semantic feature (may be recorded as template T06).
The more words a multi-word template requires to obtain, the stronger the association among words is, and then the higher the accuracy of using the established language model to add punctuation is, the more the kinds of templates are, the more comprehensive the consideration of the association between the semantic feature and punctuation status occurring in sentences is, and then the higher the accuracy of using the established language model to add punctuation is. Of course, the more the kinds of templates are, the more words a multi-word template requires to obtain, the bigger the amount of calculation required by establishing language model is, the bigger the scale of the mentioned language model is, the bigger the information processing load of using the established language model to add punctuation is.
In Step 205 , when determining the weight of each kind of punctuation status of each characteristic unit based on occurrence number of each kind of punctuation status of each characteristic unit, for the purpose of easy operation, each characteristic unit should be assigned identification (ID), the established language model including characteristic unit ID, characteristic unit corresponding to this ID, and weight information on each kind of the punctuation status of the mentioned characteristic unit.
In the present invention, semantic feature of a word can include but are not limited to part of speech and/or sentence constituent of the word in the current sentence.
The following content gives one specific example, introducing for demonstration the method of establishing a language model shown in FIG. 2 .
In this example, assuming that the following Chinese sentence is included in the text corpus: , , (English meaning: Today's weather is pretty good, let's go to play basketball this afternoon and then go to have dinner).
When using method shown in FIG. 2 to establish language model, the following steps shall be performed:
Step 1, word segmentation of the mentioned sentence shall be performed.
After word segmentation of the sentence “ , , ” is completed, the obtained words include: (today), (weather), (pretty good), (let us), (this afternoon), (go to), (play basketball), (and then), (go to), (have dinner).
Step 2, label semantic feature and punctuation status of each word in the sentence after word segmentation.
For demonstration, the mentioned semantic features include part of speech and sentence constituent, and therefore, refer to Table 1 for label result of the mentioned sentence:
TABLE 1
(pretty
(let
(this
(play
(and
(have
Content
(today)
(weather)
good)
us)
afternoon)
(go to)
basketball)
then)
(go to)
dinner)
Part of
Noun
Noun
Adjective
Pronoun
Noun
Verb
Noun
Adverb
Verb
Noun
speech
Constituent
Adverbial
Subject
Predicate
Subject
Adverbial
Predicate
Adverbial
Adverbial
Predicate
Object
modifier
modifier
modifier
modifier
Punctuation
None
None
Comma
None
None
None
Comma
None
None
Period
Step 3, according to label result in Step 2, and based on the preset characteristic template, extract characteristic unit from the mentioned sentence, distribute ID for extracted characteristic unit, and record occurrence number of each kind of punctuation status of each characteristic unit, wherein the mentioned characteristic unit including word and semantic feature of the word.
In this step, assuming that the preset characteristic templates include single word templates of T00, T01, T02 and multi-word template T05, single word template T00 is used for obtaining words and their semantic features in the current reference position, single word template T01 is used for obtaining words and their semantic features in the position prior to the current reference position, single word template T02 is used for obtaining words and their semantic features in the position after the current reference position, multi-word template T05 is used for obtaining words and their semantic features in the position prior to the current reference position, the current reference position, the position after the current reference position respectively.
Taking the position of labeled sentence in Step 2 as the current position, extract characteristic units based on single word templates of T00, T01, T02 and multi-word template T05.
For example, when taking the location of “ (weather)” as the current reference position, the obtained characteristic unit based on template T00 includes “ (today)” and semantic feature of “ (today)” (namely, noun and adverbial modifier), the obtained characteristic unit based on template T01 includes “ (weather)” and semantic feature of “ (weather)” (namely noun and subject), the obtained characteristic unit based on template T02 includes “bu cuo” and semantic feature of “bu cuo” (namely adjective and predicate), the obtained characteristic unit based on template T05 includes “ (today)” and semantic feature of “ (today)” (namely, noun and adverbial modifier), “ (weather)” and semantic feature of “ (weather)” (namely noun and subject), “bu cuo” and semantic feature of “bu cuo” (namely adjective and predicate).
Among which, information about relative position of each word in characteristic unit and the current reference position can be stored in characteristic unit explicitly, or implicitly by the way of assigning ID in corresponding range for characteristic unit according to ID range corresponding to each kind of template.
When extracting characteristic unit based on characteristic template, if there is no word in certain relative position characteristic template requires, then present none of word in the agreed method, for example, using agreed character or character string to present none of word. For example, there is no word in front of “ (today)” in the mentioned sentence, the position of “ (today)” shall be taken as the current reference position, when extracting characteristic unit based on characteristic templates of T00 or T05, it is required to use the agreed method to present that there is no word in the previous position of “ (today)”.
After characteristic unit is extracted, characteristic unit with different content can be differentiated by assigning different IDs for characteristic units. There are various methods to assign the mentioned ID, for example, it is acceptable to take the generated Hash Value based on content of characteristic unit as ID of the mentioned characteristic unit.
For each characteristic unit, every time the mentioned characteristic unit appears in sentence of corpus, record occurrence number of punctuation status of the characteristic unit according to punctuation status of each word appearing in the characteristic unit this time. Among which, punctuation status of characteristic unit includes punctuation status of each word in characteristic unit, in other words, when characteristic unit includes multiple words, punctuation status of characteristic unit consists of the combination of punctuation status of the mentioned multiple words, wherein, when punctuation status of any one of words changes, punctuation status of mentioned characteristic unit containing multiple words will also change. For example, one characteristic unit includes three words, when punctuation statuses of three words are “none”, “none” and “comma” respectively, punctuation status of this characteristic unit is a combination of “none”, “none” and “comma”, when punctuation status of the third word changes into “none”, then punctuation status of this characteristic unit changes into another kind of punctuation status, namely, it is “none”, “none” and “none”.
As shown in Step 2 and 3, advantage of the adoption of word segmentation processing instead of hyphenation processing by the present invention is that: only words have specific semantic features, while single character generally fails to have specific semantic feature, and therefore word segmentation also makes preparation for Step 2; in addition, as during the process of characteristic extraction, context information contained in sentence will be frequently involved, and context of word is still the word, relation of semantic feature can be presented more specifically by relationship among words, and interrelated semantic features have a relatively strong relationship with punctuation statuses, and thus, characteristic unit, which is extracted based on word segmentation and context relationship after word segmentation, enables to extract more accurately relationship between semantic information and punctuation status contained in sentence.
Step 4, according to characteristic unit Step 3 extracts, and the occurrence number of each kind of punctuation status of characteristic unit, determining the weight of each kind of punctuation state of each characteristic unit, establishing the language model which includes the correspondence of the weight of each characteristic unit and each kind of punctuation status of its own.
Among which, specifically, iterative optimization algorithm can be used to determine the weight of each kind of punctuation status in each one of characteristic units.
Among which, many iterative optimization algorithms can be used, for example, Newton iterative algorithm, BFGS (Large-scale Bound-constrained Optimization) iterative algorithm, L-BFGS (Software for Large-scale Bound-constrained Optimization) iterative algorithm, OWL-QN (Orthant-Wise Limited-memory Quasi-Newton) iterative algorithm, etc. Preferably, L-BFGS iterative algorithm shall be used, for the reason that L-BFGS iterative algorithm has the advantage of speedy iteration and can improve speed of establishing language model.
The language model, which is established finally based on the mentioned Step 1-Step 4, includes correspondence of the weight of each characteristic unit and each kind of punctuation status of its own, and wherein each characteristic unit also has an ID which can distinguish it from other characteristic units, and the correspondence of the weight of the mentioned characteristic unit and each kind of punctuation status of its own can be retrieved by the mentioned ID.
Based on the method of establishing language model shown in FIG. 1 , the present invention also provides a kind of device of establishing language model, and refers to FIG. 3 for more information.
FIG. 3 is the structural diagram of the establishment device of language model used for adding punctuation according to some embodiments.
As shown in FIG. 3 , this device includes word segmentation module 301 , characteristic extraction and recording module 302 , establishing module 303 .
Word segmentation module 301 , is used to conduct word segmentation processing for the sentences in corpus, and wherein, the sentences in corpus have been added punctuation in advance.
Characteristic extraction and recording module 302 , according to the semantic feature of each word in the sentences after word processing segmentation, and relying on the preset characteristic template, are configured to search for the characteristic unit occurring in the mentioned corpus, and to record the occurrence number of each kind of punctuation status of each characteristic unit in the mentioned corpus according to the punctuation status after each word in characteristic unit.
Establishing module 303 , according to the occurrence number of each kind of punctuation status of each characteristic unit, is configured to determine the weight of each kind of punctuation status of each characteristic unit, and to establish the language model which includes the correspondence of the weight of each characteristic unit and each kind of punctuation status of its own.
In which, the mentioned language model is used for providing the correspondence of the weight of each characteristic unit and each kind of punctuation status of its own in the mentioned language model according to the search request when searching out the characteristic unit from the sentences short of punctuation, so as to depend on the mentioned correspondence to add punctuation to the sentences short of punctuation.
The device shown in FIG. 3 can also include label module further.
The mentioned label module, according to the semantic information of each word in the mentioned sentence after word segmentation processing of sentence, is configured to label semantic feature for each one of the mentioned words, and to label punctuation status for each one of the mentioned words according to the punctuation status information after each one of the mentioned words in the mentioned sentence.
Characteristic extraction and recording module 302 , according to the mentioned semantic feature of each word, are configured to generate characteristic units based on preset characteristic template, the mentioned characteristic template including the number, semantic features of the obtained words, the mentioned characteristic unit including words and semantic features of words, and to search for each characteristic unit from sentences of the mentioned corpus, to record the punctuation status of the characteristic unit when each characteristic unit occurring, recording the occurrence number of each kind of punctuation status of this characteristic unit, among which, the punctuation status of the characteristic unit includes the punctuation status of each word in this characteristic unit.
The mentioned preset characteristic template also can include that obtaining the word whose relative position relationship with the current reference position satisfies preset requirements.
Characteristic extraction and recording module 302 , taking each one of words in sentence after word segmentation processing as the current reference position respectively, are configured to determine the word whose relative position relationship with the current reference position in mentioned sentence satisfies the requirements of the mentioned characteristic template, and to generate the characteristic unit based on semantic feature of the word whose mentioned relative position relationship satisfies requirements of characteristic template and relative position relationship information, and the mentioned characteristic unit also includes relative position relationship of the word with the current reference position.
The mentioned preset characteristic template can include single word template, and the mentioned single word template includes obtaining the word whose relative position relationship with the current reference position satisfies preset requirements, and semantic feature of the mentioned single word.
Characteristic extraction and recording module 302 , taking position of each word of the mentioned sentence as the mentioned current reference position respectively, are configured to determine the single word whose relative position relationship with the current reference position satisfies requirements of characteristic template of the mentioned single word, determine characteristic unit of the single word occurring in sentence to be processed based on semantic feature of the single word, and characteristic unit of the mentioned single word includes the mentioned individual word, semantic feature of the mentioned individual word and relative position relationship of the mentioned individual word with the current reference position.
And/or, the mentioned preset characteristic template can include multi-word template, and the mentioned multi-word template includes obtaining multiple words whose relative position relationship with the current reference position satisfies preset requirements respectively, and semantic feature of each word of the mentioned multiple words.
Characteristic extraction and recording module 302 , taking position of each word of the mentioned sentence as the mentioned current reference position respectively, are configured to determine the multiple words whose relative position relationship with the current reference position satisfies requirements of the relative position relationship of the mentioned multi-word characteristic template based on the mentioned multi-word characteristic template, and to determine the multi-word characteristic units occurring in sentence to be processed based on semantic feature of each word of the multiple words, and the mentioned multi-word characteristic units include the mentioned multiple words, semantic feature of the individual word of mentioned multiple words, and relative position relationship of position of the individual word with the mentioned current reference position.
After language model, mentioned in the present invention, which is used for adding punctuations is established, punctuations of the sentence to be processed can be added based on the mentioned language model, and the following content gives a specific introduction about the method and system of adding punctuations with reference to attached drawings 4 and attached drawings 5 .
Wherein language model, configured to add punctuations in the present invention, includes correspondence of the weight of each characteristic unit and each kind of punctuation status of its own, and provides correspondence of the weight of corresponding characteristic unit and each kind of punctuation status of its own according to search request, and the present invention has no limit on the mentioned method of adding punctuation and the specific method of establishing the mentioned language model used for adding punctuation by the system.
FIG. 4 is the flowchart diagram of adding punctuation method according to some embodiments.
As is shown in FIG. 4 , the method includes:
Step 401 , recognizing each word and its semantic features in the sentences to be processed.
Step 402 , according to the preset characteristic template and each word and its semantic features contained in the sentences to be processed, determining all the characteristic units occurring in the sentences to be processed.
Among which, the mentioned characteristic template includes the number, semantic features of the obtained words, the mentioned characteristic unit includes words and semantic features of words.
Step 403 , obtaining the correspondence of the weight of each characteristic unit in all the mentioned characteristic units and each kind of punctuation status of its own from the language model for punctuation adding.
Step 404 , determining the weight of punctuation status of each word in the sentences to be processed according to the obtained mentioned correspondence, and determine the comprehensive weight of various punctuation statuses in the sentences to be processed according to the weight of punctuation status of each word.
Among which, each punctuation status in the sentences to be processes includes the punctuation status of each word contained in the sentences to be processed.
Step 405 , adding punctuations to the sentences to be processed according to the mentioned comprehensive weight.
In this step, selecting out the punctuation status of the sentences to be processed with the largest comprehensive weight, and adding punctuations to the sentences to be processed according to the selected punctuation status.
Among which, in Step 404 , the weight of the punctuation status of each word in the sentences to be processed can be determined according to the correspondence of the weight of the obtained characteristic unit and each kind of punctuation status of its own. Many kinds of methods can be adopted to determine the weight of punctuation status of each word in the sentences to be processed concretely, the present invention does not limit it. For example, the weight of punctuation status of each word in the sentences to be processed can be determined according to the mentioned correspondence by the method of mapping function, concretely, for the words in the current position in the sentences to be processed, determine all the characteristic units that contain the words in the current position, and obtain the correspondence of the weight of each characteristic unit in them and each kind of punctuation status of the characteristic unit itself, according to the mapping function to determine the weight of various punctuation statuses of the words in the mentioned position. Among which, when the words with the same content is located at different positions in the sentences to be processed, they are regarded as different words, thus, their characteristic units are different, as well as their punctuation statuses.
In Step 404 , the punctuation status of mentioned sentences to be processed includes the punctuation status of each word in the sentences to be processed, which is equivalent to the combination of the punctuation status of all words in the sentences to be processed, thus the comprehensive weight of various punctuation statuses in the sentences to be processed can be determined by the optimal path algorithm, such as determine the optimal combination way of the punctuation statuses of all words in the sentences to be processed by Viterbi algorithm, i.e. determine the optimal path, and the comprehensive weight of the optimal combination way is the highest.
In the method shown in FIG. 4 , the mentioned template can also include obtaining the words whose relative position relationship with the current reference position satisfies preset requirements, the mentioned characteristic unit also includes the relative positional relation between words and the current reference position.
The mentioned determination of all the characteristic units occurring in the sentences to be processed includes:
Respectively taking the position of each word in the sentences to be processed as the current reference position, determining the words whose relative position relationship with the current reference position satisfies the requirements of the mentioned characteristic template according to the mentioned characteristic template, and determining the characteristic unit occurring in the sentences to be processed according to the semantic features of the word.
The mentioned preset characteristic template can include single word template, and the mentioned single word template includes obtaining the word whose relative position relationship with the current reference position satisfies preset requirements, and semantic feature of the mentioned single word.
The mentioned determination of all the characteristic units occurring in the sentences to be processed includes:
Respectively taking the position of each word in the sentences to be processed as the current reference position, are configured to determine the single word whose relative position relationship with the current reference position satisfies requirements of characteristic template of the mentioned single word, determine characteristic unit of the single word occurring in sentence to be processed based on semantic feature of the single word, and characteristic unit of the mentioned single word includes the mentioned individual word, semantic feature of the mentioned individual word and relative position relationship of the mentioned individual word with the current reference position.
And/or, the mentioned preset characteristic template can include multi-word template, and the mentioned multi-word template includes obtaining multiple words whose relative position relationship with the current reference position satisfies preset requirements respectively, and semantic feature of each word of the mentioned multiple words.
The mentioned determination of all the characteristic units occurring in the sentences to be processed includes:
Respectively taking the position of each word in the sentences to be processed as the current reference position, are configured to determine the multiple words whose relative position relationship with the current reference position satisfies requirements of the relative position relationship of the mentioned multi-word characteristic template based on the mentioned multi-word characteristic template, and to determine the multi-word characteristic units occurring in sentence to be processed based on semantic feature of each word of the multiple words, and the mentioned multi-word characteristic units include the mentioned multiple words, semantic feature of the individual word of mentioned multiple words, and relative position relationship of position of the individual word with the mentioned current reference position.
In the method shown in FIG. 4 , when obtaining the correspondence of the weight of each characteristic unit in all mentioned characteristic units and each kind of punctuation status of its own from the language model for punctuation adding, the search request with identification (ID) of characteristic unit can be sent to the language engine for punctuation adding, obtaining the correspondence of weight of corresponding characteristic unit and each kind of punctuation status of its own from the mentioned language model for punctuation adding according to the ID of mentioned characteristic unit, wherein, there is an ID of characteristic unit, a characteristic unit corresponding to the ID, and the correspondence of weight of the characteristic unit and each kind of punctuation status of its own in the storage of the mentioned language model for punctuation adding.
Among which, the sentences to be processed mentioned in the present invention can not only be the sentences of text type and being lack of punctuations, but also the sentences of speech type.
FIG. 5 is the composition schematic diagram of adding punctuation system according to some embodiments.
As is shown in FIG. 5 , the system includes recognition device 501 , characteristic unit extracting device 502 , weight obtaining device 503 , comprehensive weight determination device 504 and the punctuation adding device 505 .
Recognition device 501 , configured to recognize each word and its semantic features in the sentences to be processed.
Characteristic unit extracting device 502 , configured to determine all the characteristic units occurring in the sentences to be processed according to the preset characteristic template and each word and its semantic features contained in the sentences to be processed, wherein, the mentioned characteristic template includes the number, semantic features of the obtained words, the mentioned characteristic unit includes words and their semantic features.
Weight obtaining device 503 , configured to obtain the correspondence of the weight of each characteristic unit in all the mentioned characteristic units and each kind of punctuation status of its own from the language model for punctuation adding.
Comprehensive weight determination device 504 , configured to determine the weight of punctuation status of each characteristic unit in the sentences to be processed according to the obtained mentioned correspondence, and determine the comprehensive weight of each kind of punctuation status of sentences to be processed according to the weight of punctuation status of each characteristic unit, wherein, each punctuation status of the sentences to be processed includes the punctuation status of each word contained in the sentence to be processed.
Punctuation adding device 505 , configured to add punctuations to the sentences to be processed according to the mentioned comprehensive weight.
The mentioned characteristic template can also include obtaining the words whose relative position relationship with the current reference position satisfies preset requirements; the mentioned characteristic unit also includes the relative position relationship between words and the current reference position.
Characteristic extracting device 502 , configured to take the position of each word in the sentences to be processed as the current reference position respectively, determine the words whose relative position relationship with the current reference position satisfies the requirements of the mentioned characteristic template according to the mentioned characteristic template, and determine the characteristic unit occurring in the sentences to be processed according to the semantic features of the word.
The mentioned preset characteristic template can include single word template, and the mentioned single word template includes obtaining the word whose relative position relationship with the current reference position satisfies preset requirements, and semantic feature of the mentioned single word.
Characteristic extracting device 502 , configured to take the position of each word in the sentences to be processed as the current reference position respectively, are configured to determine the single word whose relative position relationship with the current reference position satisfies requirements of characteristic template of the mentioned single word, determine characteristic unit of the single word occurring in sentence to be processed based on semantic feature of the single word, and characteristic unit of the mentioned single word includes the mentioned individual word, semantic feature of the mentioned individual word and relative position relationship of the mentioned individual word with the current reference position.
And/or, the mentioned preset characteristic template can include multi-word template, and the mentioned multi-word template includes obtaining multiple words whose relative position relationship with the current reference position satisfies preset requirements respectively, and semantic feature of each word of the mentioned multiple words.
Characteristic extracting device 502 , configured to take the position of each word in the sentences to be processed as the current reference position respectively, are configured to determine the multiple words whose relative position relationship with the current reference position satisfies requirements of the relative position relationship of the mentioned multi-word characteristic template based on the mentioned multi-word characteristic template, and to determine the multi-word characteristic units occurring in sentence to be processed based on semantic feature of each word of the multiple words, and the mentioned multi-word characteristic units include the multiple words, semantic feature of the individual word, and relative position relationship of position of the individual word with the mentioned current reference position.
Weight obtaining device 503 , configured to send search request with identification (ID) of characteristic unit to the language model for punctuation adding, obtain the correspondence of weight of corresponding characteristic unit and each kind of punctuation status of its own from the mentioned language model for punctuation adding according to the ID of mentioned characteristic unit, wherein, there is an ID of characteristic unit, a characteristic unit corresponding to the ID, and the correspondence of weight of the characteristic unit and each kind of punctuation status of its own in the storage of the mentioned language model for punctuation adding.
Among which, the sentences to be processed can not only be the sentences of text type and being lack of punctuations, but also the sentences of speech type. When the sentence to be processed is the sentence of speech type, the recognition device 501 includes speech recognition engine, the mentioned speech recognition engine can recognize the words contained in the sentences of speech type and the semantic features of each word according to the acoustic model, dictionary and the language model which is used for recognizing the semantic features of sentences.
FIG. 6 is a block diagram illustrative of the components of a computer system 3 in accordance with some embodiments. The computer system 600 typically includes one or more processing units (CPU's) 602 , one or more network or other communications interfaces 604 , memory 610 , and one or more communication buses 609 for interconnecting these components. The communication buses 609 may include circuitry (sometimes called a chipset) that interconnects and controls communications between system components. The computer system 600 may include a user input device 605 , for instance, a display 606 and a keyboard 608 . Memory 610 may include high speed random access memory and may also include non-volatile memory, such as one or more magnetic disk storage devices. Memory 610 may include mass storage that is remotely located from the CPU's 602 . In some embodiments, memory 602 , or alternately the non-volatile memory device(s) within memory 602 , comprises a non-transitory computer readable storage medium. Memory 602 or the computer readable storage medium of memory 602 stores the following elements, or a subset of these elements, and may also include additional elements:
an operating system 612 that includes procedures for handling various basic system services and for performing hardware dependent tasks; a network communication module 614 that is used for connecting the computer system 600 to a remote computer (e.g., a on-line chat server) or other computers via one or more communication networks (wired or wireless), such as the Internet, other wide area networks, local area networks, metropolitan area networks, and so on; a user interface module 616 configured to receive user inputs through the user interface 605 ; a language model establishing application 618 for establishing a language model using training information content; in some embodiments, the language model establishing application 618 further including:
a word segmentation module 301 as described above in connection with FIGS. 1-3 ; a characteristic extracting and recording module 302 as described above in connection with FIGS. 1-3 ; and a language model establishing module 303 as described above in connection with FIGS. 1-3 ;
a punctuation mark addition application 620 for adding punctuation marks to information content based on a language model; in some embodiments, the punctuation mark addition application 620 further including:
a recognition module 501 as described above in connection with FIGS. 4-5 ; a characteristic unit extracting module 502 as described above in connection with FIGS. 4-5 ; a weight obtaining module 503 as described above in connection with FIGS. 4-5 ; a comprehensive weight determination module 504 as described above in connection with FIGS. 4-5 ; and a punctuation adding module 505 as described above in connection with FIGS. 4-5 .
While particular embodiments are described above, it will be understood it is not intended to limit the invention to these particular embodiments. On the contrary, the invention includes alternatives, modifications and equivalents that are within the spirit and scope of the appended claims. Numerous specific details are set forth in order to provide a thorough understanding of the subject matter presented herein. But it will be apparent to one of ordinary skill in the art that the subject matter may be practiced without these specific details. In other instances, well-known methods, procedures, components, and circuits have not been described in detail so as not to unnecessarily obscure aspects of the embodiments.
The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used in the description of the invention and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will also be understood that the term “and/or” as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items. It will be further understood that the terms “includes,” “including,” “comprises,” and/or “comprising,” when used in this specification, specify the presence of stated features, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, operations, elements, components, and/or groups thereof.
As used herein, the term “if” may be construed to mean “when” or “upon” or “in response to determining” or “in accordance with a determination” or “in response to detecting,” that a stated condition precedent is true, depending on the context. Similarly, the phrase “if it is determined [that a stated condition precedent is true]” or “if [a stated condition precedent is true]” or “when [a stated condition precedent is true]” may be construed to mean “upon determining” or “in response to determining” or “in accordance with a determination” or “upon detecting” or “in response to detecting” that the stated condition precedent is true, depending on the context.
Although some of the various drawings illustrate a number of logical stages in a particular order, stages that are not order dependent may be reordered and other stages may be combined or broken out. While some reordering or other groupings are specifically mentioned, others will be obvious to those of ordinary skill in the art and so do not present an exhaustive list of alternatives. Moreover, it should be recognized that the stages could be implemented in hardware, firmware, software or any combination thereof.
The foregoing description, for purpose of explanation, has been described with reference to specific embodiments. However, the illustrative discussions above are not intended to be exhaustive or to limit the invention to the precise forms disclosed. Many modifications and variations are possible in view of the above teachings. The embodiments were chosen and described in order to best explain the principles of the invention and its practical applications, to thereby enable others skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated.
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A method of processing information content based on a Chinese language model is performed at a computer, the method including: identifying a plurality of expressions in the information content extracted from a speech input through speech recognition that is queued to be processed; dividing the expressions into a plurality of characteristic units according to semantic features and predetermined characteristics associated with each characteristic unit, each including a subset of the expressions and the predetermined characteristics at least including a respective integer number of expressions that are included in the characteristic unit; extracting, from the Chinese language model, a plurality of probabilities for punctuation marks associated with each characteristic unit; and in accordance with the probabilities, associating a respective punctuation mark with each characteristic unit included in the information content. The method further comprises adding punctuation marks based on a weight determined for each punctuation mark.
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FIELD OF THE INVENTION
The subject matter of this application relates to methods of reducing waste, particularly fats, oils and grease (FOG) and that waste which increases biochemical oxygen demand (BOD) (collectively “organic waste”) in collection systems such as sewer lines, lift stations, treatment plants and similar such effluent transfer and storage facilities (collectively “effluent facilities”).
BACKGROUND
Many types of waste are poured down drains. Fats, oils, and grease (“FOG”) are common such wastes that are present in meats, cooking and salad oils, cooking grease, lard, butter, margarine and multitude of other foodstuffs. Additionally, FOG may also refer to non-edible fats, oils, and greases.
FOG, in particular, poses a problem for sewer systems because fats, oils, and greases are largely insoluble in water and will accumulate over time in drainage pipes, as well as further down the sewer path. These accumulations may not only primarily restrict waste water flow thought the pipe, but can also secondarily restrict water flow by providing a substrate where solid waste can stick. These restrictions may build to the point where the pipe is sufficiently blocked so that waste water will back up into homes and businesses causing expensive damage and requiring further corrective actions to increase the flow of waste water. Since most buildings have a single common sewer pipe for all waste water, the results of a backup of water can be much more unpleasant than the backing up of only water from a sink.
Home and restaurant kitchens, as well as catering and institutional food services can spend thousands of dollars to repair the damage caused by the buildup of FOG. The sequela of a clogged drain can cause a home to be temporarily inhabitable and force a business to close until the sewer drain is cleared and the damage is cleaned and repaired. The advantages to keeping drains free of any build up before a blockage occurs are clear, however the most common preventative measures often include the use of corrosive chemicals that are dangerous to handle and store, and which are not environmentally sound.
The problems with FOG waste are not limited to individual buildings, municipalities also have to contend with the build up of FOG in shared sanitary sewer lines as well as in treatment plants and any other effluent transfer and storage facilities. A municipality's expenses associated with keeping the accumulation of FOG minimal through the use of physical methods can be substantial. These costs, however, are preferable to having to clean (if possible) or replace sections of sewer that have become impassible to waste water due to the severe accumulation of insoluble waste. These blockages, which are often caused by FOG, can cause a sanitary sewer overflow (an “SSO”). An SSO is not only expensive to fix and clean itself, but in the event of an SSO, the US Environmental Protection Agency may issue substantial fines to the governing municipality. Additionally, if such an overflow contaminates the drinking water supply, the resulting public health emergency will require, at the least, the issuance of a boil order, where all affected people need to boil water before consuming it. In more extreme cases, boiling may be insufficient and clean water will need to be brought in, or the people moved out, until the water is again made drinkable.
Among the methods of mitigating FOG buildup are two common physical methods: hydro-jetting and pumping. Hydro-jetting essentially involves spraying the effluent facility (such as a sewer line) with high pressure water to break up any blockages. Generally, the hydro-jetting begins at the end of the blockage most distal to the originating drain and is directed upstream, towards the most proximal end of the blockage. In this manner, loosened material drains away from the blockage. A disadvantage to hydro-jetting is that no material is removed, it is simply broken up and washed more distal to the originating drain, where it may re-aggregate into another blockage further downstream. Accumulations in municipality controlled common sewer lines or effluent facilities can effect multiple buildings and multiple drains and create problems that are much more difficult and expensive to repair than a localized blockage.
Pumping is a much different solution to the problem of FOG buildup. In pumping, FOG is pumped from a point of accumulation and then otherwise disposed. The removed FOG may be, inter alia, recycled, converted into bio-diesel, enzymatically degraded, or placed into a landfill. The costs associated with pumping, transporting the recovered FOG, and disposing it can be substantial.
A different water contaminant is known as Biochemical oxygen demand (“BOD”). BOD is a procedure used to determine the amount of oxygen needed in a sample of water to allow aerobic bacteria to break down the organic material in said sample. It is often expressed as milligrams of oxygen consumed per liter of sample after a five day incubation at 20 degree Celsius, and is used as an indirect measurement of the organic pollution in water. In typical parlance, BOD is listed as a pollutant itself, such as in the U.S. Clean Water Act, although it is actually a measurement of organic contaminants. This typical usage is used in the application.
BOD includes all organic matter found in waste water. Fallen leaves and decaying plant material are the predominant natural sources of this organic matter, however the greatest sources of BOD, at least in developed area, can be traced to human impact. Runoff of nutrients from lawn fertilizers, grass clippings, paper, food scraps pushed down a disposal, and fecal matter, all contribute to the amount of organic material found in waste water. A sample's BOD directly relates to the amount of organic waste it contains, so lower BOD values indicate a lower amount of organic waste.
The potential for damage caused by the accumulation of FOG, as well as the additional processing required for waste water heavily polluted with FOG and BOD to ensure compliance with the Federal Clean Water Act and other relevant regulations, has caused municipalities to shift costs through the use of contaminant surcharges. For businesses such as food processing facilities that expel high FOG and BOD waste water, these contaminant surcharges can total in the tens of thousands a month.
Methods of using biological materials to reduce foodstuffs and FOG in waste water are known in the art.
Australian Patent AU739218B2 discloses a composition consisting of, inter alia, bacteria and free enzymes, that will digest macerated foodstuffs in a garbage disposal unit. This composition may also be used when macerated foodstuffs are in a drain line, proximal to the garbage disposal unit.
U.S. Pat. No. 6,187,193B1 discloses a method of decomposing FOG in a grease trap apparatus. The apparatus of the '193 patent holds drainage and stirs or splashes it via a rotating impeller or a sprinkler that sprinkles drainage onto the top of the held drainage pool. Aerobic bacteria are supplied to the drainage pool and the agitation caused by the spinning impeller or sprinkler supplies the bacteria with oxygen. Waste water processed by this apparatus are then expelled to a sewer system.
U.S. Pat. No. 7,338,692B1 discloses a method of reclaiming FOG from a grease trap using a recyclable solvent so that the FOG can be further processed or disposed.
U.S. Patent application 2008/0251451 A1 discloses a method and an apparatus for treating waste in which one or more reactor vessels accepts inputs of waste and of aerobic bacteria, an aeration means aerates the waste and supports the aerobic bacteria, and the treated waste water can be removed through an outlet means.
U.S. Pat. No. 6,325,934B1 discloses a granular substance comprising bacteria and enzymes in a heavy material that releases the bacteria and enzymes over a period of between a day and two weeks an water. The granular material is made heavy so that the particles sink into accumulated sludge in the bottom of a sewage digestion chamber, in this way minimizing dilution of the active ingredients in grey water above the sludge.
U.S. Pat. No. 6,706,518B2 discloses a method and apparatus for clearing FOG in which a dry agent comprising bacteria and enzymes is incubated to form an aqueous solvent capable of cleaning and clearing FOG. After production, this solvent is placed in contact with FOG to catalyze digestion of the FOG.
U.S. Pat. No. 5,464,766 discloses a powdered product consisting of, inter alia, enzymes and bacteria that can be delivered to a site containing organic waste in order to digest such waste.
These methods may be useful, but some require specialized, and perhaps also expensive equipment, while others are best suited for removal of accumulated waste products which may not be discovered until a drainage problem is discovered. Some would not reduce the pollution in the waste water entering a sewer or the contamination surcharges that may be imposed by a municipality.
SUMMARY
The subject matter of this application is a method to reduce organic waste, particularly fats, oils, and grease (FOG) in waste water. The disclosed methodology is also useful for catalyzing the degradation of any substance that can be used as a carbon source by wild-type or mutant bacteria. A wide range of pollutants can therefore be targeted by this methodology through the selection of bacterial strains, such selection being within the routine experimentation one in the microbiological arts would expect to encounter.
The method disclosed in this application involves a nutritive, gelatinous culture of vegetative, predominantly adult bacteria contained in a porous vessel such as a mesh bag which is at least partially submerged in a moving or still body of waste water. In a preferred embodiment, the porous vessel is tethered to a fixed or movable object so that it can be easily removed from the waste water. The pores of said porous vessel are sufficient in size to permit the passage of bacteria through the pores. As the gelatinous culture dissolves in the waste water, bacteria are released that bio-digest the organic waste found therein. The porous vessel affects the dissolution rate of the bacterial culture by reducing the flow of waste water through said vessel. In embodiments in which the porous container is tethered to an object, the gelatinous culture can be readily removed from the waste water at any time by retracting the porous vessel, although in most applications, the porous vessel will be left in the waste water after placement until the gelatinous culture has completely dissolved.
By providing vegetative, adult bacteria to the waste water, which continue to propagate in the waste water and digest said organic waste, the method substantially decreases the organic waste in the waste water in an environmentally sound manner. Further, the use of adult cultured bacteria means that the bacteria is able to digest organic waste shortly after being released into the waste water, without first needing to pass through a germination stage as may be required of methods using immature bacteria. Also, since the bio-activity associated with the bacterial culture does not depend on the use of free enzymes, which do not replicate, the bio-activity is sustained and may propagate as necessary to digest larger amounts of organic waste than would be possible with a similar sized mass of free enzymes. The porous vessel that contains the gelatinous culture may be easily recovered and can be recycled or disposed of in an appropriate manner.
BRIEF DESCRIPTION OF THE DRAWINGS
A complete understanding of the subject matter of this application may be obtained without reference to drawings, however, to ease such understanding of the subject matter, applicant provides two drawings.
FIG. 1 is an illustrated chart showing a preferred embodiment of the disclosed method in use.
FIG. 2 is a graph summarizing the results of the use of the disclosed method in the treatment of the waste water from a food processing facility.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The following description and drawings referenced therein illustrate an embodiment of the application's subject matter. They are not intended to limit the scope. Those familiar with the art will recognize that other embodiments of the disclosed method are possible. All such alternative embodiments should be considered within the scope of the application's claims.
Each reference number consists of three digits. The first digit corresponds to the figure number in which that reference number is first shown. Reference numbers are not necessarily discussed in the order of their appearance in the figures.
This application discloses a method of treating waste water. Use of the method can reduce pollutants that can be digested by bacteria, particularly fats, oils and grease (FOG) and biochemical oxygen demand (BOD), (collectively “organic waste”) in collection systems such as sewer lines, lift stations, treatment plants and similar such effluent transfer and storage facilities (collectively “effluent facilities”)
A nutritive gelatinous mass suited for growing and supporting vegetative bacteria is formed from the gelling of a broth consisting of sodium chloride, sucrose, dried milk, seaweed agar, and microencapsulated D-limonene. The exact composition of the broth can be varied and customized as may be needed by one of skill in relevant arts, such as microbiology. The gelled mass may be inoculated with vegetative bacteria, such as those belonging to the genera Bacillus, Saccharomyces , and Pseudomonas , or such bacteria may comprise part of the broth. The resulting bacterial culture may gel, at least partially, in a porous vessel, or the culture may be fully gelled before it is placed within such a vessel. In one embodiment, the culture is held within a mesh bag [ 101 ]. In useful embodiments, the pores of the porous vessel must be large enough to allow bacteria to flow out as the gelatinous mass dissolves in waste water.
In a preferred embodiment, the porous vessel containing the gelatinous bacterial culture is tethered to a movable or a fixed object so that the vessel does not wash away and can be easily recovered. Most often, the vessel will not be removed until the bacterial culture has completely dissolved, although that does not have to be the case. In useful embodiments, the bacterial culture is in contact with waste water flowing, or standing, in an effluent facility, such as, e.g. a sewer line, lift station, or treatment plant. The waste water that enters through the pores of the porous vessel partially dissolves the bacterial culture, and passes out of the porous vessel, carrying with it some amount of the cultured bacteria.
In a preferred embodiment, the porous vessel is a mesh bag that is sealed around the gelatinous bacterial culture so that the culture is contained in the mesh bag as it is handled. In a most preferred embodiment, one end of a rope or chain [ 106 ] is reversibly of permanently attached to a fixed structure, such as a rung of a ladder found inside of an utility vault such as which may be accessed through a man hole or similar opening [ 102 ] and the other end of the rope is attached to a carabiner or D-ring [ 103 ], which is, in turn, connected to the culture-containing mesh bag [ 101 ]. The mesh bag, and thereby the bacterial culture, is lowered into the waste water [ 104 ]. The mesh bag containing the bacterial culture may be fully or partially submerged in the waste water, or it may float on top of the waste water depending upon the buoyancy of the mesh bag and bacterial culture, and on the specific gravity of the waste water. In this way, the bacterial culture [ 105 ] contacts the waste water passing through the pores of the mesh bag and the bacterial culture slowly dissolves in the waste water, gradually releasing the bacteria. The dissolution rate will vary based on factors such as the volume and rate of waste water passing through the effluent facility and may be altered by making changes to the composition of the gelatinous mass or to the pore size of the vessel.
In one trial, results of which are summarized in FIG. 2 , waste water leaving a food processing facility in the town of St. Mary in Ontario, Canada was treated with the method disclosed in this application. Prior to treatment, said facility was routinely expelling waste water with between 3,000 and 6,000 mg/L BOD and between 1,000 and 3,000 mg/L FOG and because of this high degree of contamination, was incurring surcharges from the town of St. Mary as high as $40,000 per month. Two mesh bags, such as those described, each containing approximately 250 ml of a nutritive gelatinous bacterial culture, also as described, and containing approximately 10^12 total bacteria, were lowered into the facility's sewer line so that the mesh bags, and therefore the bacterial culture contained in the bags, were in contact with the waste water as if flowed from the facility's drains. Completely, or almost completely, dissolved bacterial cultures were replaced during the treatment period. In FIG. 2 , black columns illustrate pre-treatment values and grey columns illustrate values obtained after six months of treatment with the disclosed method.
To measure the contaminant reduction due to treatment with the disclosed method, samples were drawn from sampling stations in the sewer line downstream from the locations of the bacterial containing mesh bags.
Prior to the placement of the bacterial cultures, the waste water had been measured as containing 1410 mg/L FOD, 3200 mg/L BOD, 1170 mg/L total suspended solids, and 14.6 mg/L phosphorus. After six months of treatment with the disclosed method, measurements of the waste water indicated that all four measured quantities had been reduced so that the waste water contained 13 mg/L FOD, 475 mg/L BOD, 29 mg/L total suspended solids, and 1.11 mg/L phosphorus. Surcharges for excess contamination were completely eliminated.
Modifications and changes, readily apparent to those of routine skill in the relevant arts, can be made to the disclosed method without departing from the novel scope and spirit of the invention. The examples and embodiments given herein are to describe a manner or manners in which the disclosed method may be used, however they should not be considered to limit the scope of the claimed method.
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A method of treating waste water is disclosed which comprises placing a porous container such as a mesh bag containing a gelatinous culture of vegetative bacteria into waste water. The gelatinous culture dissolves over time and releases the bacteria contained therein. In some embodiments, the porous container may be reclaimed at any time. Treatment with the method eliminates a substantial portion of organic waste found in waste water and reduces or eliminates the need for used to eliminate organic waste build up in waste water facilities.
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RELATED APPLICATION
[0001] This patent application claims the benefit of co-pending U.S. Provisional Patent Application No. 61/432,212, filed on Jan. 13, 2011, which is hereby incorporated by reference in its entirety.
TECHNICAL FIELD
[0002] The present disclosure relates to an implantable electrode lead for transmitting electrical impulses to excitable bodily tissue and/or for transmitting electrical signals tapped at bodily tissue to a detection unit. The implantable electrode lead generally includes a distal electrode, a proximal electrode connector, and an electrode lead which connects the electrode or each electrode, or is used to transmit electrical shocks or to control sensors, and which extends in a lead body.
BACKGROUND
[0003] Such electrode leads, which are used to transmit (e.g., stimulation impulses from cardiac pacemakers to the heart, or possibly action potentials that occur at the heart to the cardiac pacemaker, or the shock impulses of an implanted cardioverter to the heart, and possibly action potentials tapped at the heart to the cardioverter, or which are used to stimulate regions of the brain or nerves, or to transmit electrical signals tapped at the brain/nerve regions to a detection and evaluation device, are used on a large scale for clinical applications.
[0004] Of the numerous fields of application for electrode leads, there are a few in which they are exposed, at least in subsections, to high mechanical loads which can impair the functionality or even disable the electrode lead entirely during long-term use. Examples thereof include, but are not limited to, cardiac pacemaker electrode leads, one or more supply leads between an implanted control device and one or more implantable sensors, and ICD electrodes that have one or more very large areas for the application of very high current pulses into the tissue over a large surface area.
[0005] First, excess length of the electrode is enclosed in the pacemaker pocket. A tenacious connective-tissue membrane grows around the structure. At the points at which the electrode comes in contact with the housing or intersects other electrode sections, high pressure loads can be placed on the lead body since the connective tissue growing around it does not allow the electrode to yield. Proceeding there from, the electrode extends generally through the region between the clavicle and the first costal arch. If the electrode is in an unfavorable position, it can become pinched.
[0006] Extensive developmental work in the past resulted in various possible solutions to this problem. Electrode leads are designed to be highly flexible. The hard materials, such as, for example, metal, that are used for the supply leads are configured to be highly flexible. Wires are wound into coils or are woven very thinly to form ropes. Plastics that are soft and as elastic as possible are used as insulators that offer the least possible resistance to the movements of the electrode.
[0007] The known solutions have not proven to be entirely satisfactory in practice. For example, if radial pressure is applied, the insulation material yields in a manner such that the pressure ultimately acts on the supply leads. Moreover, the pinching of the insulation material stresses the plastic. The stress can cause the material to degrade or directly cause it to yield mechanically. The insulation wears off, bursts, or degrades. Initially, the insulation is breached. Bodily fluid can penetrate the electrode and close electrolyte bridges between the leads. Shunts or short circuits can negatively affect therapy. In the worst case, however, the supply leads break and therapy fails. Furthermore, it can not be ruled out that a broken electrode body will cause further damage.
[0008] The problems addressed by the present description are therefore that of providing an improved electrode lead which is more resistant to substantially radially acting forces and friction, at least in certain sections in particular, while remaining as flexible as necessary.
[0009] The present inventive disclosure is directed toward overcoming one or more of the above-identified problems.
SUMMARY
[0010] One or more problems are solved by an electrode lead having the features of the independent claim(s). Further advantageous developments are the subject matter of the dependent claims.
[0011] In this context, the term “hard elements” refers to separate elements or even delimitable sections in the longitudinal extension of a lead body, which are extremely resistant (“hard”) to forces that act radially or obliquely to the longitudinal axis of the electrode lead and are short relative to the total length of the electrode lead. According to the present disclosure, at least those sections in the longitudinal extension of an electrode lead that are typically exposed to strong mechanical loads of that type are designed to be particularly resistant.
[0012] An electrode lead designed on the basis of the solution according to the present description is substantially more stable against mechanical loads to which it is exposed in practical application. The radial compression and flexing forces being applied are absorbed here by an additional shield, namely, the hard elements. The functional components, i.e., the supply lead, which is comprised of rope or coil or combinations thereof, and the insulators, which are comprised of plastic, are limited in terms of their actual function (namely, to conduct or insulate). In conventional electrodes, due to the radial forces acting thereon, these functional elements had to withstand various loads, such as, for example, torsional moments, tensile forces, flexing forces, and friction. An optimal embodiment of the solution according to the present description also provides permanent protection against unwanted movements of the electrode body. For example, relative motions between the supply lead and the insulation can be minimized.
[0013] Further aspects of embodiments of the present description are the following, which represents a non-exhaustive list:
[0000] 1. Materials for at least a portion of the hard elements can be:
[0014] Metal: Platinum, tantalum, iridium, palladium, steel, MP35N, gold, etc.
[0015] Ceramic: Al2O3, ZrO2, TiO2, MgO, ZnO, aluminum titanate (Al2O3+TiO2), barium titanate (BaO+TiO2), silicon carbide (SiC), beryllium oxide (BeO), aluminum nitride (AlN), hafnium carbide (HfC), tantalum carbide (TaC), titanium nitride (TiN), boron nitride (BN), boron carbide (B4C), tungsten carbide (WC), silicon nitride (Si3N4), etc.
[0016] Glass:
[0017] Plastic: PEEK, silicone, various copolymers, polyimide, PA, high-density polyethylene, polysulphone, or variants of the aforementioned plastics filled with fibers or nanoparticles, etc.
[0000] 2. The hard elements alternate with elastic elements (sections).
3. The quality of the elements changes along the extension of the electrode.
4. The hard elements of the chain are interconnected by an elastic material.
5. The elastic material is applied by extrusion or coating or injection molding of the chain.
6. The elements of the chain are enclosed in an elastic material.
7. The supply lead body is enclosed in an abrasion-resistant tube.
8. At least one coil or one reinforcing wire extends in the core of the chain, e.g., in a lumen
9. At least one rope extends in the core of the chain.
10. The coil(s) or the rope(s) or combinations thereof are insulated from one another and/or from the chain.
11. The openings are asymmetrical (a core lumen need not be provided).
12. The elements of the chain are insulators.
13. The elements of the chain are semiconductors.
14. The elements of the chain are conductive.
15. The shape of the elements changes depending on the function.
16. Individual elements have different lengths.
17. Individual elements have different diameters.
18. Individuals elements of the chain are designed as a ring electrode or can accommodate a ring electrode.
19. Individuals elements of the chain are designed as sensors or can accommodate sensors.
20. Individuals elements of the chain are designed as coils or can accommodate coils.
21. Individuals elements of the chain are designed as capacitors or can accommodate capacitors.
22. Individual elements of the chain contain electronic components, analog or digital circuits or combinations thereof, accumulators, batteries, antenna, transmitters, or receivers or combinations thereof.
23. Individual elements of the chain are designed as fixation elements or can accommodate fixation elements, which are used to affix the electrode at the intended location thereof.
24. The elements have openings for the eccentrically extending supply leads, which define the path in which they extend.
25. The eccentrically extending supply leads are disposed in parallel to the axis of the electrode body.
26. The eccentrically extending supply leads are coiled around the axis of the electrode body.
27. The eccentrically extending supply leads are coiled around the axis of the electrode lead, wherein the slope of the coil changes along the electrode length, reverses (winds in the opposite direction), or approaches infinity, i.e., extends in parallel.
28. The end faces (contact surfaces) of the elements to the adjacent elements are designed in a manner (e.g., flattened) such that the chain is easier to bend.
29. The contact surfaces of the elements are designed in a manner such that, if bent, the minimum bending radius of the chain is limited.
30. The elements are designed in a manner such that the degree of freedom of motion toward the adjacent elements is limited. Elements perform joint functions (i.e., the chain no longer bends in all directions at this transition of the chain elements), wherein the elements designed as joints are designed such that they can absorb tensile forces (a so-called “reaching behind”).
31. The plane of motion toward the subsequent element is rotated by an angle, e.g., of approximately 90°.
32. The eccentrically extending supply leads are guided in the joint plane from one element to the next (thereby minimizing the motion of the lead relative to the element).
33. The elements are injection molded onto a tube or are extruded thereon.
34. The above-described elements are separated from each other by special elements which function as joints.
35. The elements are interconnected by integrated joints.
36. The elements are made from a tube.
37. The elements are aligned in a row, e.g., overlapped in a shingled formation.
38. The sections of the tube are interconnected.
39. The tube is made from one continuous piece, in particular, using, for example, laser-beam cutting.
40. The type of chain changes along the extension of the electrode. Segments of the electrode body are designed as chains and others use traditional design principles of the electrode body.
[0018] Various other objects, aspects and advantages of the present inventive disclosure can be obtained from a study of the specification, the drawings, and the appended claims.
DESCRIPTION OF DRAWINGS
[0019] Advantages and useful features of the present description also result from the descriptive examples that follow, with reference to the figures. They show:
[0020] FIG. 1 is a schematic representation of a conventional implantable electrode lead.
[0021] FIG. 2 shows, in a perspective sectional view, an example of a highly developed electrode lead comprising a plurality of supply leads accommodated in one lead body.
[0022] FIG. 3 shows, in a perspective sectional view, a further highly developed electrode lead comprising a plurality of supply leads in a coaxial arrangement.
[0023] FIGS. 4A-4B and FIGS. 5A-5B each show schematic depictions of an electrode lead designed according to the present description, in a side view.
[0024] FIGS. 6A-6C each show, in schematic perspective sectional views, a hard element of an embodiment of the electrode lead according to the present description.
[0025] FIG. 7 is a schematic side view of a section of a further electrode lead according to the present description.
[0026] FIG. 8 are perspective depictions of three hard elements of an embodiment of the electrode lead shown in FIG. 7 .
[0027] FIG. 9 is a perspective depiction of adjacently disposed, hard elements of a further electrode lead according to the present description.
[0028] FIG. 10 is a schematic side view of a further embodiment of the present description.
[0029] FIG. 11 is a schematic perspective depiction of a section of a further electrode lead according to the present description.
[0030] FIG. 12 is a schematic longitudinal sectional view of a further embodiment of the present description, in which a hard element also performs an electrical function.
[0031] FIG. 13 is a perspective view of a further embodiment of the present description.
[0032] FIGS. 14A-14B are side views of a section of the electrode body of a further electrode lead according to the present description.
[0033] FIGS. 15A-15B are sketches of further embodiments of the electrode lead according to the present description.
[0034] FIG. 16 is a sketch of a further embodiment of the present description.
DETAILED DESCRIPTION
[0035] In the description of the various Figures that follow, similar reference numerals are used for identical or identically-acting parts or sections, and previous descriptions are not repeated for subsequent Figures provided they refer to such parts and no special circumstances exist. Embodiments of the present disclosure are illustrated by way of example, and not by way of limitation, in the Figures.
[0036] FIG. 1 is a schematic depiction of a bipolar electrode lead 1 , on the distal end of which a point electrode 3 a and a ring electrode 3 b are disposed. Two corresponding electrode contacts 5 a and 5 b are provided on the proximal end thereof, each being connected to the respective associated electrode 3 a, 3 b by a first and a second supply lead 7 a, 7 b, respectively. The electrodes, 3 a, 3 b, electrode contacts, 5 a, 5 b, and supply leads 7 a, 7 b are accommodated on or in a lead body 9 , which typically comprises multiple layers.
[0037] FIG. 2 shows, in a perspective sectional view having various cutting planes, an electrode lead 201 , in the case of which three lumina 208 a having a smaller diameter and an additional lumen 208 b having a larger diameter are provided in an inner tube 209 a, which is the core of a supply lead body 209 . Each of the smaller lumina 208 a contains an electrode supply lead 207 a having a rope structure which is provided with an insulating jacket comprised of, e.g., PTFE, ETFE or PI, and which is not labeled separately. A supply lead coil 207 b, which can accommodate a guide wire during implantation to reinforce the electrode lead, extends in larger lumen 208 b. To improve the sliding and wear properties of lead body 209 , it is provided with an outer shell 209 b which positively influences these properties.
[0038] FIG. 3 shows a further embodiment of an implantable electrode lead, in the case of which an inner coil 307 a, which comprises a plurality of wound individual wires, is disposed, as the first electrode supply lead (or the first group of supply leads), coaxially to an outer coil 307 b , which likewise comprises a plurality of wound individual wires (and which can likewise form a group of electrode supply leads). A silicone tube 309 a is provided between the inner coil 307 a and the outer coil 307 b, and the outer coil 307 b is enclosed by a further insulating tube 309 b which can likewise be comprised of, for example, silicone or a polyurethane or a copolymer. A combination of a plurality of tubes can also be used here.
[0039] FIGS. 4A and 4B show, schematically in a side view, a section of an electrode lead 401 designed according to the present description, in which a group of disk-shaped, hard, closely interspaced elements 402 is disposed, as protection against strong mechanical loads, on a lead body 409 which contains an electrode supply lead 407 . The elements 402 are spaced such that the electrode lead 401 can bend in the stated section (see FIG. 4B ). The minimal bending radius is generally determined by the spaced distance of the hard elements 402 . FIGS. 5A and 5B show a similar electrode lead 501 which differs from that shown in FIGS. 4A-4B only by the tight alignment of protective hard elements 502 on lead body 509 , and by the shape of these elements 502 . Both end faces of the elements 502 are conical (and therefore the overall shape is approximately disk-shaped), thereby enabling the electrode lead 501 to bend in the stated section (see FIG. 5B ) despite the tight alignment. The minimal bending radius is determined by the cone angle of the end faces of hard elements 502 .
[0040] FIGS. 6A-6C show perspective depictions of various shaped hard elements 602 . 1 , 602 . 2 and 602 . 3 . All embodiments have the main shape of a cylinder or a disk, and a central lumen 608 a for a first electrode supply lead, which is not depicted. Hard element 602 . 1 , as shown in FIG. 6A , also comprises two radial recesses 608 b and 608 c, in which further electrode supply leads can be placed. In the case of hard element 602 . 2 , shown in FIG. 6B , and 602 . 3 , shown in FIG. 6C , a second inner lumen 608 b ′ is provided in place of one radially open recess 608 b . Moreover, in the case of hard element 602 . 3 , shown in FIG. 6C , remaining recess 608 c ′ is curved, as, for example, a section of a coil, and so when a plurality of similarly shaped elements are disposed in a row, a coiled extension of this recess or groove results and can be used to determine an identical coiled extension of an electrode supply lead placed therein.
[0041] In the case of hard elements 602 . 1 , 602 . 2 , 602 . 3 shown in FIGS. 6A-6C , central lumen 608 a can accommodate, for example, a guide wire, a tube, a coiled electrode supply lead, or a rope-like electrode supply lead. Supply leads that are rope-like and extend separately or are designed as thin coils can be accommodated in the recesses, which are accessible from the outside, or in further lumina. The recesses, which are accessible from the outside, can be formed subsequently in the electrode lead. This is not an option, however, when disposed in smaller lumen 608 b ′, but the rope-shaped or coiled supply lead extending therein is better insulated against the surroundings. Structures formed in this manner provide a certain amount of protection for the supply lead if they are intended to be guided under a ring electrode or a shock coil.
[0042] FIG. 7 shows, in a schematic side view, as another embodiment of the present description, an electrode lead 701 in a bent state. The electrode lead 701 likewise comprises hard elements 702 aligned in a section which is exposed to special mechanical loads. The main shape of the hard elements 702 is cylindrical, having the one end face of which has a triangularly notched cross section, and the other end face of which has a projecting contour that matches the shape of the aforementioned triangular notch. Similar to the embodiment shown in FIGS. 5A and 5B , this shape of the hard elements also enables the electrode lead to bend with a predetermined minimum radius.
[0043] FIG. 8 shows, as an embodiment of the design shown in FIG. 7 , three hard elements 802 which are adjacent to one another and are detached from the actual lead body, in the case of which a central lumen 808 a as well as a laterally offset, smaller lumen 808 b are provided in each hard element 802 . The second lumen 808 b is situated close to a plane of symmetry of the hard elements 802 , which simultaneously determines the plane—which is orthogonal thereto—in which the electrode lead provided with such elements 802 can bend, thereby ensuring that the rope extending there through is neither substantially stretched nor substantially compressed when the electrode lead bends. As a result, relative movements between the electrode supply lead accommodated in the lumen and the protective elements are largely prevented.
[0044] Another embodiment of the design principle depicted in sketches in FIGS. 7 and 8 is shown in FIG. 9 in the form of a group of hard elements 902 a, 902 b, 902 c. In addition to a central lumen 908 a, these elements each comprise two radial grooves 908 b and 908 c which do not extend parallel to the central lumen 908 a (and therefore in the longitudinal direction of the particular element), but rather obliquely thereto. According to this embodiment, a group of hard elements is shaped—being coordinated with one another—such that the plane of symmetry of the notch on an end face is oriented orthogonally to the orientation of the notch on the other end face, simultaneously ensuring a continuous, coiled extension of radial grooves 908 b, 908 c over all elements in the row. Thus, the electrode body can bend in any direction even if only three chain elements are aligned.
[0045] FIG. 10 shows, schematically, as another embodiment of the present description, a group of three hard elements 1002 which are to be applied onto or in an electrode lead body. The hard elements 1002 are characterized by a spherical or circular disk-shaped projection 1002 . 1 on the one end face, which is otherwise, for example, conical in shape, and a matching ball socket 1002 . 2 on the other end face which has a shallower slope and is likewise conical in shape. In the installed state, the balls or circular disks 1002 . 1 and ball sockets and circular disk sockets 1002 . 2 form a rotationally symmetrical joint connection between the hard elements 1002 , thereby enabling an electrode lead equipped therewith to bend in any direction.
[0046] As an alternative to the joint connection sketched in FIG. 10 , FIG. 11 shows another solution for ensuring high bendability in the form of an electrode lead 1101 . Lead 1101 comprises a lead body 1109 which typically is comprised of an elastic plastic material, and the internal components (special supply leads) of which are not depicted here. First hard elements 1102 a and second hard elements 1102 b are slid onto lead body 1109 in alternation. The depiction in FIG. 11 is purely schematic, although it illustrates how first hard elements 1102 a have a cylindrical to barrel-type main shape and both of their end faces have a concave shape, while second hard elements 1102 b have an approximately spherical main shape and engage the first hard elements 1102 a in the concave end faces. This engagement also results in the formation of a type of ball joint, thereby enabling the electrode lead 1101 to bend in all planes.
[0047] FIG. 12 shows, in a schematic longitudinal cross-sectional view, another electrode lead 1201 according to the present description, which comprises an electrode supply lead 1207 , a group of first hard elements 1202 a which protect the supply lead 1207 , and a lead body 1209 which is situated on the outside in this case and encloses supply lead 1207 with hard elements 1202 a placed thereon. A unique feature of the embodiment shown in FIG. 12 is that an individual hard element 1202 b of a second type is inserted between disk-shaped, hard elements 1202 a. This different element 1202 b is generally drum-shaped and contains in the interior thereof a coil 1206 which is an additional electrical component and is connected mechanically and electrically to central electrode supply lead 1207 . This connection can be configured as an electrical series circuit, thereby increasing the inductance of the electrode supply lead 1207 . The drum-shaped housing of hard element 1202 b is rotatably supported on the electrode supply lead 1207 , thereby enabling the lead body 1209 to rotate relative to the electrode supply lead 1207 with the coil 1206 securely placed thereon and preventing torsional stresses from forming during use of the electrode lead 1201 .
[0048] FIG. 13 shows, as another embodiment of the present description, an electrode lead 1301 which is protected by hard elements 1302 a, the design of which is similar to the embodiment depicted in FIG. 6A . Electrode lead 1301 comprises a ring electrode 1310 which is situated as a ring around the outer circumference of a different hard element 1302 b. In the case of element 1302 b, second radial recess 1308 c is reduced in size such that a supply lead 1307 c accommodated therein is forced into mechanical and electrical contact with the inner wall of ring electrode 1310 , which is thereby connected electrically to supply lead 1307 c. The connection can also be fixed using a welding point or other known means.
[0049] FIGS. 14A and 14B show two fundamentally different embodiments of “hard elements” for protecting an electrode lead. In both embodiments, a tube 1400 or 1400 ′ is machined (e.g., using a laser cutting procedure or other known means) in a manner such that non-machined and therefore rigid (“hard”) sections 1402 and 1402 ′ alternate with (“soft”) machined sections 1404 and 1404 ′, which are deformed relatively easily due to the recesses created by the machining. In the embodiment depicted in FIG. 14A , soft sections 1404 are created using a strip-type incision that extends in a spiral. In the embodiment depicted in FIG. 14B , soft sections 1404 ′ are created using circular incisions applied such that they alternate by approximately 90°, thereby ensuring that the electrode lead protected by the protective tube 1400 , 1400 ′ can bend in at least two planes.
[0050] To illustrate another embodiment of the present description, FIG. 15A shows a lead body 1509 having a central lumen 1508 for receiving electrode supply leads (not depicted), which is formed by enclosing relatively greatly interspaced hard elements 1502 in a coating of an elastic mass applied by injection molding. By applying the coating via injection molding at a relatively great distance, “soft”, i.e., flexurally resilient and flexibly yielding, lead body sections 1504 are formed between each of the hard elements 1502 and ensure that the final electrode lead is sufficiently flexible. FIG. 15B shows, as an alternative design having a comparable function, a lead body 1509 ′ which is formed by pressing rounded, disk-shaped (lenticular), hard elements 1502 ′ onto a tube 1509 a comprised of a flexurally resilient and compressible material disposed at a predetermined distance from one another. In this case as well, distance ranges 1504 between hard elements 1502 ′ are deformed relatively easily and therefore represent a type of hinged connection between the “hard” sections.
[0051] FIG. 16 shows, in a sketch of another embodiment of the present description, a distal section of an electrode lead 1601 . In the electrode lead 1601 , first hard elements 1602 a, which are used exclusively for protection against mechanical stress, are provided, as well as an element 1602 b comprising a securing hook 1611 which can be extended after implantation. The securing hook 1611 (shown extended in FIG. 16 ) is controlled using a guide wire (not shown) for securing the electrode lead 1601 in the patient's bodily tissue. Element 1602 b, comprising the securing hook 1611 , is situated close to a distal electrode 1603 of lead 1609 .
[0052] The embodiment of the present description is not limited to the above-described examples and emphasized aspects, but rather is possible in a large number of modifications that lie within the scope of a person skilled in the art. Those of skill in the art will readily appreciate that embodiments in accordance with the present invention may be implemented in a very wide variety of ways. This application is intended to cover any and all adaptations and/or variations of the embodiments discussed herein.
[0053] The terms and expressions which have been employed in the foregoing specification are used therein as terms of description and not of limitation, and there is no intention, in the use of such terms and expressions, to exclude equivalents of the features shown and/or described or portions thereof, it being recognized that the scope of the invention is defined and limited only by the claims that follow.
[0054] It will be apparent to those skilled in the art that numerous modifications and variations of the described examples and embodiments are possible in light of the above teachings of the disclosure. The disclosed examples and embodiments are presented for purposes of illustration only. Other alternate embodiments may include some or all of the features disclosed herein. Therefore, it is the intent to cover all such modifications and alternate embodiments as may come within the true scope of this invention, which is to be given the full breadth thereof. Additionally, the disclosure of a range of values is a disclosure of every numerical value within that range.
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An implantable electrode lead for transmitting electrical impulses to excitable bodily tissue and/or for transmitting electrical signals tapped at bodily tissue to a detection unit. The electrode lead including a distal electrode, a proximal electrode connector, and an electrode supply lead which connects the electrode, or each electrode, to the electrode connector, or each electrode connector, and extends in a lead body, wherein the lead body includes a hinged alignment of hard elements.
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FIELD OF THE INVENTION
The present invention relates to an optical sighting device which is positionable within the barrel of a firearm such as a shotgun and which emits a beam of light. More particularly, the invention relates to an optical device which, upon actuation, projects a beam of light which simulates the pattern or path of a shell discharged from a shotgun or other firearm.
BACKGROUND OF THE INVENTION
As most firearm shooters know, a fundamental element of shooting requires that the eye and the end of the barrel be directed to the same target point at the moment the trigger is pulled. If the shooter's eye and the firearm barrel are not converged on the target, the target will be missed. The present invention is an optical device which emits a beam of light which assists in training the shooter to properly direct the firearm in relationship to the shooting posture of the individual shooter. Various shooters hold firearms in different positions which, along with physical differences of the shooters, will affect the line of fire. With the present system, a shooter can develop an accurate, repeatable shooting posture through practice.
In addition to assisting the shooter in improving shooting skills, the sighting device of the present invention can also assist the shooter in initially "sighting" a shotgun.
The sighting device of the present invention can be used as an impact or training system as described above which helps individuals in developing accurate, repeatable shooting postures. In the impact or training mode of operation, the device will emit a continuous laser light beam for as long as the operator or shooter maintains pressure on the triggering switch.
In another mode, the present invention may be used as a field device for improving shooting skills and also for competitive practice. As a field device, the device allows the firearm to be aimed duplicating actual shooting conditions that may be encountered in bird hunting or trial shooting. A switch allows a pulse of light to be generated instead of a continuous beam of light.
SUMMARY OF THE INVENTION
Briefly the above objects are accomplished by a device which is insertable in the choke end of a shotgun barrel. The device may be sized for various gauges of shotguns such as a 20 gauge or 12 gauge shotgun. The device has an elongated tubular body having front and rear sections which are detachably connected at an intermediate location. Cylindrical lugs are arranged at spaced-apart locations about the body of the device having an outer diameter slightly less than the internal diameter of the shotgun bore. The tubular body carries an external spring which engages the bore of the barrel to properly seat the device in precise alignment with the axis of the bore. The body contains a power source such as batteries, a light-emitting circuit including a light source and an objective lens. The lens is mounted so that the focal length of the lens can be adjusted to provide the desired pattern simulating the pattern of a shotgun. The lens housing is also adjustable so that it may be calibrated so that the beam of light emitted is properly aligned with the axis of the bore of the shotgun.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other objects and advantages of the present invention will become more readily apparent from the following description, claims and drawings in which:
FIG. 1 depicts a shooter aiming a shotgun equipped with the sighting device of the present invention;
FIG. 2 is a view of the end of a shotgun partly broken away to illustrate the position of the sighting device in the end of the bore;
FIG. 3 is a perspective view of the sighting device of the present invention;
FIG. 4 is an exploded perspective view of the sighting device of the present invention;
FIG. 5 an enlarged detail view of the outer end of the sighting device of the present invention;
FIG. 6 illustrates a shooter's hand showing an actuating switch carried on the first finger;
FIG. 7 is a schematic view of the light-emitting circuit; and
FIG. 8 is a sectional view taken along line 8--8 of FIG. 2.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The sighting device of the present invention is generally designated by the numeral 10 and in FIG. 1 the device is shown inserted in the end of the barrel 14 of shotgun 16. The shooter 5 is shown aiming the shotgun 16. The sighting device 10 projects a beam of light B which at the target has spread in a pattern "P" representative of the pattern of a shotgun shell fired by a shotgun 16.
Referring to FIGS. 1 to 5, the body of the sighting device 10 has a front tube 20 and a rear tube 22. The front tube 20 has a generally elongated tubular body 24 defining an internal cylindrical chamber 26. The rear end of the front tube 20 is threaded at 28. The front end of tube 20 tapers outwardly to a head 30 having an annular rim 32 of a diameter greater than the front tube. A counter bore 38 extends rearwardly from the opening in the head 30 terminating at shoulder 39 at the intersection with bore 26.
The rear tube 22 has an end lug cap 42 which is generally cylindrical having a diameter slightly less than the diameter of a bore of a shotgun with which the device is to be used. Another lug 44 is positioned at the forward end of the rear tube having a diameter corresponding to the diameter of lug 42. The diameter of lugs 42 and 44 are, for example, in the case of a standard 12 gauge shotgun, approximately 0.050 inches less in diameter than the diameter of the shotgun or approximately 0.680 inches in diameter. This allows the device to be easily inserted into the bore of the shotgun at the choke end of the barrel and is supported by resting on a part of the circumference of the lugs. Lug 44 is provided with internal threads 48 which permit the front tube 20 to be placed in threaded engagement with the rear tube at threads 48 and 28.
A retention spring assembly 50 secures the sighting device in place in the bore as best seen in FIG. 2. The spring assembly includes a pair of spaced-apart, semicircular clips 52 and 54 with an arch shaped spring member 56 extending between the clips. The clips 52, 54 are positioned on the rear tube 22 with clip 52 adjacent lug 42. The spring 56 exerts a biasing force against the interior of the bore causing the sighting device to seat in the bore with the lugs engaging the bottom part of the bore, as best seen in FIGS. 2 and 8. In position, the longitudinal axis of the sighting device and the longitudinal axis of the bore are not precisely co-axial but are closely aligned and are parallel. The axis of the sighting device is vertically aligned with the axis of the bore as seen in FIG. 8 but is displaced a distance below the bore axis. This differential is so slight that it will not materially effect the accuracy of the device and the differential remains linear and is not compounded with distance.
The circuit components are mounted on PCB 60 and are connected to light source 62. Power for the circuit is provided by batteries 64 and 66 which for example may be conventional AAA alkaline batteries. The batteries are received within the battery chamber within the rear tube and are insertable at 48. PCB 60 is positioned within the bore 26 in the front tube rearward of the head 32. The circuit board is electrically connected to light source 62 which is shown as a laser diode but may be an LED or other light source. The light source is received within cylindrical housing 72 which loosely fits into counter bore 38. An alignment cap 80 is positioned within the head of the front tube and has a body 85 which is in threaded engagement with the housing 72 at 81. The alignment cap has disc-like end member 84 which has a diameter generally corresponding to the diameter of rim 32. An annular gasket 86 is interposed between the end 84 and the head 30. End member 84 defines a plurality of radially extending slots 88, three being shown. The slots 88 extend inward from the periphery of the end and are adapted to receive screws 90 which are in threaded engagement with threaded bores 92 which extend axially in head 30 arranged about bore 38.
The end member 84 defines a threaded opening 98 centrally positioned within the member. An adjustment screw 100 has a body in threaded engagement with the opening 98. The adjustment screw also defines a central bore 102. Notches 105 are provided at the outer end of the body of the adjusting screw 100 to permit the adjusting screw to be rotated to advance or retract the screw with respect to threaded opening 98. The inner end of the screw carries a circular seat 110 against which lens 115 abuts. A compression spring 120 extends within the holder 72 between the light source 62 and the lens 115.
Switch 160 is connected to the PCB by means of cables 125 and 126. Cable 125 connects to the PCB through grommet 130 at bore 131 in the front tube. The opposite end of the cable 125 is provided with a female connector 135. As will be explained hereafter, the user may select an appropriate mode switch 160 to be connected to the device by cable 126 and connectors 135, 136 depending upon the desired mode of operation.
The light-emitting circuit is best shown in FIG. 7 and as shown consists of a laser photo diode 62 having components D 1 and D 2 , NPN transistors Q 2 , fixed resistors R 2 and R 4 , variable resistor D 2 , and fixed capacitors C 1 and C 2 . When energized, the laser diode 62 will emit a beam of light directed at lens 115. The light emitted from the lens is gathered within the light gathering tube 102 and projected from the outer end of the tube as generally concentric circles of light. The switch employed is shown as switch 160 and may be conveniently placed upon the first finger of the user by a band 162 which is shown having a conventional loop and hook fastener.
Alternately, the switch may be detachably secured by band 162 to the receiver or other part of the shotgun.
The switch 160 has cable 126 terminating at a male connector 136 which is engageable with female connector 135. Switch 160 may be selected to connect S 1 with a ground in which case the mode of operation is one in which a continuous beam of light is emitted. As an alternative, switch 160 can be selected so as to connect point S 2 with ground across capacitor C 2 . In this operational mode, a pulse of light is generated rather than a continuous beam. The switch 160 operates to generate another pulse only when the shooter releases the switch and again depresses it. This mode, the field mode, duplicates firing an actual round as opposed to the continuous beam mode which is intended for sighting the gun and training the shooter in the proper shooting posture.
The lens 115 may be any suitable lens such as a molded plastic objective lens. One lens that has been found to work is a bi-asphere polycarbonate lens with a 1.2 millimeter diameter, a focal length at 4.6, numerical aperture 0.47, beam diameter 4.3 mm, and axial wave point distortion at 780 nanometers less than 0.02. A lens of this type is available from the optical products division of The Eastman Kodak Company in Rochester, N.Y.
Once the device is assembled as described above, it is generally necessary to calibrate the device, this can be done by placing the device in proper alignment tooling and energizing the light source 62. The set screws 90 are adjusted so that a beam of light is emitted from the end of the bore 102. The beam should be precisely aligned with the axis of the bore of the shotgun. The focal length of the device is adjusted by rotating the screw 100 until the desired pattern is obtained at the desired distance. For example, a typical calibration would be to set the device to project a generally circular pattern having approximately a 26" diameter at 30 yards which approximates the effective shot pattern area of a 12 gauge shotgun set at full choke at this distance. As mentioned above, the device of the present invention is intended to allow the shooter to sight a shotgun and also to practice shooting skills, both in target and field situations. The device may be used to project a simulated shotgun pattern on nearly any flat surface, although it may be helpful to use a target having a retroreflective surface.
In use, with the device inserted through the choke end of the shotgun as shown in FIG. 1 and with a continuous mode switch 160 positioned on the finger of the user, the switch is connected to the PCB at connectors 135, 136. The shooter will pick a point, as for example, on a flat surface 30 feet away and point the shotgun in a manner as if shooting the shotgun. The shooter will actuate the switch 160 and note the relationship between the aim point and the point where the laser beam impact indicates the barrel was actually pointing. The device will emit a very brief flash when the switch is actuated and the beam of light may be maintained by continuous actuation of the switch. This allows the shooter to adjust the gun to determine how various gun positions change the position of the laser light relative to the shooters line of sight. This enables the shooter to find the proper position that provides the most accuracy. Practice in this manner will enable the shooter to assume a better shooting and more accurate shooting posture.
The switch 160 can be replaced with a pulse switch simply by disconnecting connectors 135 and 165 and replacing the switch which will operate to energize the circuit across capacitor C 2 . Use of a pulse mode enables the shooter to practice in a manner simulating actual field shooting or trap line shooting. With the pulse switch, a beam of light is emitted only with each depression of the switch, as for example for 22 milliseconds. Special retroreflective targets again may be helpful when these targets are struck by a beam of light, the target will return a bright red flash that is easily visible to the shooter.
The invention has been described with the preferred light source being a laser diode because of the desirable characteristics of laser light. However, other light sources such as LED's and even conventional flashlight bulbs may be used.
While the principles of the invention have been made clear in the illustrative embodiments set forth above, it will be obvious to those skilled in the art to make various modifications to the structure, arrangement, proportion, elements, materials and components used in the practice of the invention. To the extent that these various modifications do not depart from the spirit and scope of the appended claims, they are intended to be encompassed therein.
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A sighting device positionable in the end of the bore of a shotgun which emits a beam of light which simulates a shot pattern. The device has a tubular body which is held in the bore by a biasing spring. The body includes a light source, preferably a laser diode, which emits a beam. The beam may be focused at an adjustable lens and may be adjusted so the beam of light is aligned with the axis of the bore. An actuating switch may be secured to a finger of the user or to the shotgun.
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CROSS REFERENCE(S) TO RELATED APPLICATIONS
[0001] This application claims the benefit under 35 U.S.C. Section 119 of Korean Patent Application Serial No. 10-2011-0065187, entitled “Multilayer Ceramic Substrate and Method for Manufacturing the Same” filed on Jun. 30, 2011, which is hereby incorporated by reference in its entirety into this application.
BACKGROUND OF THE INVENTION
[0002] 1. Technical Field
[0003] The present invention relates to a multilayer ceramic substrate and a method for manufacturing the same, and more particularly, to a multilayer ceramic substrate for repairing a void around a via and a method for manufacturing the same.
[0004] 2. Description of the Related Art
[0005] In recent, as miniaturization of electronic parts intensifies and continues, small-sized modules and substrates have been developed by precision-making, fine-patterning, and thinning the electronic parts. However, when a normally used printed circuit board (PCB) is applied in the small-sized electronic part, there occur disadvantages, such as size reduction, signal loss at a high frequency region, and deterioration in reliability at high temperature and high humidity.
[0006] A substrate using ceramics instead of the PCB is used in order to overcome these disadvantages. A main component of a multilayer ceramic substrate is a ceramic composition allowing low-temperature co-firing and containing a large amount of glass.
[0007] A low temperature co-fired ceramic (LTCC) substrate may be manufactured by various methods, which are divided into a shrinkage process and a non-shrinkage process according to whether or not the multilayer ceramic substrate shrinks at the time of firing.
[0008] Specifically, the multilayer ceramic substrate is shrunken and manufactured at the time of firing according to the shrinkage process. However, in the shrinkage process, a shrinking degree of the multilayer ceramic substrate is not uniform throughout the multilayer ceramic substrate, and thus, a dimension change occurs in a surface direction of the substrate. This shrinkage in the surface direction of the multilayer ceramic substrate causes printed circuit patterns included in the substrate to be deformed, thereby deteriorating precision of pattern position and causing short circuits in the patterns.
[0009] The non-shrinkage process for preventing the shrinkage in the surface direction of the multilayer ceramic substrate at the time of firing is being proposed, in order to solve the problems caused by the shrinkage process.
[0010] According to the non-shrinkage process, restriction layers are formed on both surfaces of the multilayer ceramic substrate at the time of firing. In this case, a material, which is not shrunken at a temperature at which the multilayer ceramic substrate is fired and easily shrinkage-controlled, may be used for the restriction layer. The multilayer ceramic substrate is not shrunken in the surface direction thereof by the restriction layer, but can be shrunken only in a thickness direction thereof.
[0011] As such, when the multilayer ceramic substrate is manufactured by applying this non-shrinkage process, the shrinkage in the surface direction of the substrate can be suppressed at the time of firing. However, a via vertically formed for interlayer connection does not correspond to firing characteristics of a normal low temperature co-fired ceramic (LTCC) and has difficulty in giving a restriction force for suppressing the shrinkage in the surface direction, and thus, voids are generated.
[0012] In particular, when the voids around the via are exposed to a surface layer, and this causes external patterns to be defective. In other words, the voids around the via appear in various types, such as a void, a crack, a protrusion, a depression, and the like, which causes defects in packaging, such as wire bonding, SMT, soldering, or the like, and deterioration in reliability.
SUMMARY OF THE INVENTION
[0013] An object of the present invention is to provide a member for preventing a binding strength between an external electrode and a ceramic laminate from being lowered, by filling a void around a via of the ceramic laminate with nanoparticles.
[0014] According to an exemplary embodiment of the present invention, there is provided a method for manufacturing a multilayer ceramic substrate, which has a ceramic laminate including multiple ceramic layers and allowing interconnection between layers through vias respectively formed in the multiple ceramic layers, the method including: preparing a ceramic laminate in which a void is formed around a via in at least one ceramic layer of multiple ceramic layers; immersing the ceramic laminate in a precipitating bath in which an electrode solution is contained; putting the ceramic laminate out of the precipitating bath after a predetermined period of time, and then removing a nanoparticle film stacked on a surface of a multilayer ceramic substrate; and applying heat to the multilayer ceramic substrate to form nanoparticles filling an inside of the void, after the removing of the nanoparticle film.
[0015] According to an exemplary embodiment of the present invention, there also is provided a method for manufacturing a multilayer ceramic substrate, which has a ceramic laminate including a deep ceramic layer and a superficial ceramic layer and allowing interconnection between layers through vias respectively formed in the multiple ceramic layers, the method including: preparing a ceramic laminate in which a void is formed around a via in at least one ceramic layer of the deep ceramic layer and the superficial ceramic layer; placing the ceramic laminate on a bottom surface in an empty precipitating bath, and then pouring an electrode solution into the precipitating bath; putting the ceramic laminate out of the precipitating bath after a predetermined period of time, and then removing a nanoparticle film stacked on a surface of a multilayer ceramic substrate; and applying heat to the multilayer ceramic substrate to form nanoparticles filling an inside of the void, after the removing of the nanoparticle film.
[0016] According to an exemplary embodiment of the present invention, there also is provided a multilayer ceramic substrate, which has a ceramic laminate including multiple ceramic layers and allowing interconnection between layers through vias respectively formed in the multiple ceramic layers, the multilayer ceramic substrate including: a ceramic laminate having a void formed around a via in at least one ceramic layer of the multiple ceramic layers; an external electrode formed on the ceramic laminate; and nanoparticles filing the void to electrically connect the ceramic laminate and the external electrode.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 is a cross-sectional view of a multilayer ceramic substrate according to an exemplary embodiment of the present invention; and
[0018] FIGS. 2A to 2E are cross-sectional views showing a method for manufacturing a multilayer ceramic substrate according to an exemplary embodiment.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0019] Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings. However, the exemplary embodiments are described by way of examples only and the present invention is not limited thereto.
[0020] Further, when it is determined that the detailed description of the known art related to the present invention may obscure the gist of the present invention, the detailed description thereof will be omitted. Further, the following terminologies are defined in consideration of the functions in the present invention and may be construed in different ways by the intention or customs of the users and operators. Therefore, the definitions thereof should be construed based on the contents throughout the specification.
[0021] The technical idea of the present invention is determined by the claims and the exemplary embodiments herein are provided so that the technical idea of the present invention will be efficiently explained to those skilled in the art to which the present invention pertains.
[0022] Hereinafter, a multilayer ceramic substrate according to exemplary embodiments of the present invention will be described with reference to the accompanying drawings.
[0023] FIG. 1 is a cross-sectional view of a multilayer ceramic substrate according to an exemplary embodiment of the present invention.
[0024] As shown in FIG. 1 , a multilayer ceramic substrate 100 according to an exemplary embodiment of the present invention may include a ceramic laminate 110 and an external electrode 135 .
[0025] The ceramic laminate 110 may include multilayer-laminated ceramic layers 112 and 114 . Here, the multilayer-laminated ceramic layers 112 and 114 may have first and second vias 122 and 124 , respectively, which include a conductive material filling via holes (not shown) pas sing through a body, for example, a silver (Ag) material. The respective ceramic layers 112 and 114 are electrically connected by the first and second vias 122 and 124 .
[0026] Meanwhile, the first via 122 fills a via hole, which is formed to pass through a superficial ceramic layer 112 of the multilayer-laminated ceramic layers 112 and 114 , on the drawing, and the second via 124 fills a via hole, which is formed to pass through a deep ceramic layer 114 of the multilayer-laminated ceramic layers 112 and 114 , on the drawing.
[0027] An inner electrode 130 is further provided between the laminated ceramic layers 112 and 114 , and electrically connected to the first and second vias 112 and 124 .
[0028] The first and second vias 122 and 124 , which vertically passes through the ceramic layers 112 and 114 , respectively, may be formed by forming via holes in the respective ceramic layers 112 and 114 at appropriate positions in a punching type, depending on circuits of a module, and then filling the via holes with a conductive material, such as silver (Ag) or the like.
[0029] In particular, a hole type void (not shown) is formed inside the superficial ceramic layer 112 , of the multiple ceramic layers 112 and 114 constituting the ceramic laminate 110 of the multilayer ceramic substrate 100 according to an exemplary embodiment of the present invention, to expose one surface of the first via 122 .
[0030] Here, the void (not shown) is not formed at random. The void is formed since positions of patterns included in the multilayer ceramic substrate are changed due to shrinkage in a surface direction of the multilayer ceramic substrate, in manufacturing the multilayer ceramic substrate.
[0031] Therefore, according to the present invention, the void (not shown) is filled with nanoparticles 140 to be repaired, and thus, can be electrically connected to the via 122 . For example, the nanoparticles 140 according to the exemplary embodiment of the present invention may be made of a conductive material having a nanoparticle, such as nano silver (Ag), nano ceramic, or the like.
[0032] Meanwhile, the external electrode 135 is electrically connected to the nanoparticles 140 and the via 122 .
[0033] As such, in the multilayer ceramic substrate 100 according to the exemplary embodiment of the present invention described above, the void around the first via 122 is generated in a type of a void, a crack, a protrusion, or a depression, due to shrinkage difference between the ceramic layers 112 and 114 and the vias 122 and 124 , at the time when the ceramic laminate 110 obtained by laminating the inner electrode 130 and multiple ceramic layers 112 and 114 having the first and second vias 122 and 124 is low-temperature co-fired. Here, the void is filled with nanoparticles 140 , and thus, can be repaired.
[0034] As such, in the multilayer ceramic substrate 100 according to the exemplary embodiment of the present invention, a binding strength between an external electrode 135 and a ceramic laminate 110 can be prevented from being lowered, by filling the voids around the via 122 of the ceramic laminate 110 with nanoparticles 140 , and forming the external electrode 135 on the nanoparticles 140 and a surface of the via 122 .
[0035] Therefore, according to the exemplary embodiment of the present invention, electric reliability can be improved in a process of forming an external electrode 135 on the ceramic laminate 110 and a subsequent packaging process, such as SMT, wire bonding, soldering, and the like.
[0036] In the exemplary embodiment of the present invention, the ceramic laminate 110 is drawn and described as having the two ceramic layers 112 and 114 stacked, but this is not limited thereto since the two ceramic layers are drawn only for convenience of explanation.
[0037] In addition, in the exemplary embodiment of the present invention, the void is drawn and described as being formed only around the first via 122 formed in the superficial ceramic layer 112 , for convenience of explanation, but not limited thereto. For example, void or voids may be formed to expose both lateral surfaces of the first via 122 , or formed to expose one lateral surface or both lateral surfaces of the second via 124 formed in the deep ceramic layer 114 .
[0038] FIGS. 2A to 2E are cross-sectional views showing a method for manufacturing a multilayer ceramic substrate according to an exemplary embodiment.
[0039] First, as shown in FIG. 2A , a multilayer ceramic substrate 100 , where a void 140 a around a via 122 is formed, is prepared.
[0040] Here, the multilayer ceramic substrate 100 of the present invention may consist of a ceramic laminate 110 including multilayer-laminated ceramic layers 112 and 114 . Although not shown in the drawing, restriction sheets (not shown) are laminated on upper and lower surfaces of the ceramic laminate 110 , and the restriction sheets may be fired at a temperature higher than a firing temperature of the ceramic layers 112 and 114 , for example, 1500° C. or higher. Here, an alumina (Al 2 O 3 ) sheet or the like may be used as the restriction sheet (not shown).
[0041] Here, first and second vias 122 and 124 may be formed in the multilayer-laminated ceramic layers 112 and 114 , respectively, and the first and second vias 122 and 124 include a conductive material filling the via holes (not shown) passing through a body, for example, a silver (Ag) material.
[0042] In addition, an inner electrode 130 is further provided between the laminated ceramic layers 112 and 114 , and electrically connected to the first and second vias 122 and 124 . Here, the inner electrode 130 may be formed by using a conductive material such as silver (Ag) in a screen printing type or the like.
[0043] Meanwhile, the void 140 a in the present invention is generated in a type of void, crack, protrusion, or depression, due to shrinkage difference between the ceramic layers 112 and 114 and the vias 122 and 124 , at the time when the ceramic laminate 110 , which is obtained by laminating the inner electrode 130 and multiple ceramic layers 112 and 114 having the first and second vias 122 and 124 , is low-temperature co-fired.
[0044] Here, in the present invention, the void 140 a is drawn and described as being formed only around the first via 122 formed in the superficial ceramic layer 112 , for convenience of explanation, but not limited thereto. For example, void or voids may be formed to expose both lateral surfaces of the first via 122 , or formed to expose one lateral surface or both lateral surfaces of the first via 122 , and the second via 124 formed in the deep ceramic layer 114 .
[0045] Referring to FIG. 2B , the ceramic laminate 110 having the void 140 a is immersed in a precipitating bath 150 , which is filled with an electrode solution 160 .
[0046] Here, the electrode solution 160 is a solution where a nanopowder is mixed with water (H 2 O) or an organic solvent (hereinafter, referred to as ethanol) solution, and the agglomerated nanopowder is uniformly dispersed by ball milling or ultrasonic dispersion.
[0047] Here, the nanopowder in the present invention may be, for example, a conductive material, such as silver (Ag) or ceramic, having nano-level particles.
[0048] Meanwhile, in the present invention, a case where the ceramic laminate 110 having the void 140 a is immersed in the precipitating bath 150 filled with an electrode solution 160 , is drawn and described, but is not limited thereto. For example, as an alternative method, the ceramic laminate 110 having the void 140 a is put inside an empty precipitating bath 150 , that is to say, nothing is there, and then the electrode solution 160 is poured into the precipitating bath 150 .
[0049] Referring to FIG. 2C , a nanoparticle film 170 is formed to cover the entire front surface and the void 140 a of the ceramic laminate 110 .
[0050] More specifically, when the ceramic laminate 110 having the void 140 a is immersed in the precipitating bath 150 in which the dispersed electrode solution 160 is contained, the nanopowder sinks onto a surface of the ceramic laminate 110 and a bottom surface of the precipitating bath due to gravity. As a result, the void 140 a of the ceramic laminate 110 can be filled and a nanoparticle film 170 covering the entire surface may be formed.
[0051] Meanwhile, in the drawing of the present invention, a silver (Ag) nano powder is drawn as an example, but not limited thereto. For example, a ceramic nano powder is substituted therefore.
[0052] Referring to FIG. 2D , the nanoparticle film 170 formed on the surface of the ceramic laminate 110 is removed, thereby manufacturing the multilayer ceramic substrate 100 having nanoparticles 140 .
[0053] More specifically, the ceramic laminate 110 having the void 140 a is immersed in the precipitating bath 150 in which the dispersed electrode solution 160 is contained, and then, after the passage of a predetermined period of time, the ceramic laminate 110 having the nanoparticle film 170 is put out from the precipitating bath 150 .
[0054] Then, the nanoparticle film 170 is scraped out by using a squeeze or a paddle, and thus, it can be removed from the surface of the ceramic laminate 110 . Here, since the squeeze or paddle is moved in a direction parallel with the ceramic laminate 110 , the nanoparticles 140 embedded inside the void 140 a is not removed.
[0055] Meanwhile, in the present invention, the passage of the predetermined period of time, for example, means a time period while an inside of the void 140 a is entirely filled with the nanopowder.
[0056] Referring to FIG. 2E , firing is performed by application of heat, thereby preventing the nanoparticles 140 from getting out of the void 140 a. Here, the heat may be applied at a temperature of 300 to 400° C.
[0057] Then, an external electrode 135 is formed on the ceramic laminate 110 in which the nanoparticles 140 and the first via 122 are formed, thereby preventing the reliability of the substrate from being deteriorated due to the void around the first via 122 . Here, the external electrode 135 may be formed of, for example, a conductive material, such as silver (Ag), like the inner electrode 130 .
[0058] Therefore, according to the exemplary embodiment of the present invention, an electric connection can be favorably performed in a process of forming an external electrode 135 on the ceramic laminate 110 and a subsequent packaging process, such as SMT, wire bonding, soldering, and the like. Therefore, the present invention can improve the reliability of the non-shrinkage multilayer ceramic substrate and lower the fraction defective.
[0059] As set forth above, the present invention can prevent a binding strength between an external electrode and a ceramic laminate from being lowered, by filling a void around a via of the ceramic laminate with nanoparticles and forming the external electrode on the nanoparticles and a surface of the via.
[0060] In addition, the present invention can improve electric reliability in a process of forming the external electrode on the ceramic laminate and a subsequent packaging process, such as SMT, wire bonding, soldering, and the like.
[0061] While the present invention has been shown and described in connection with the embodiments, it will be apparent to those skilled in the art that modifications and variations can be made without departing from the spirit and scope of the invention as defined by the appended claims.
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Disclosed herein are a multilayer ceramic substrate and a method for manufacturing the same. In a method for manufacturing the multilayer ceramic substrate, which has a ceramic laminate including multiple ceramic layers and allowing interconnection between layers through vias respectively formed in the multiple ceramic layers, the method includes: preparing a ceramic laminate in which a void is formed around a via in at least one ceramic layer of multiple ceramic layers; immersing the ceramic laminate in a precipitating bath in which an electrode solution is contained; putting the ceramic laminate out of the precipitating bath after a predetermined period of time, and then removing a nanoparticle film stacked on a surface of a multilayer ceramic substrate; and applying heat to the multilayer ceramic substrate to form nanoparticles filling an inside of the void, after the removing of the nanoparticle film.
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BRIEF DESCRIPTION OF THE INVENTION
1. Field of the Invention
This invention relates to ovens for the baking of bread and the like and is particularly concerned with an oven that is capable of continually baking flat Arabic-style bread that rises to a limited extent during the baking process and that desirably has a relatively hard outer crust and that is quite chewy in comparison with the usual American-style breads.
2. Prior Art
There have been a great many bread baking ovens developed in the past. Generally, these ovens provide for a uniform heating of the product being baked as the product is moved on a conveyor from an entrance-way to an exit. While suitable for many types of baking, and especially for the baking of American-style breads, such ovens are not suitable for use in the baking of Arabic-style bread, in that they do not provide for an initial bottom heating and a subsequent top heating of the bread and do not provide for proper venting as the bread is baked.
SUMMARY OF THE INVENTION
It is the principal object of the present invention to provide an oven suitable for the continuous baking of Arabic-style breads and the like.
Other objects are to provide such an oven that will allow the continuous feeding of Arabic-style bread dough in one end, a heat application from beneath the bread dough until the dough begins to rise slightly and bake and a subsequent application of heat from above, while removing the direct heat application from below, to properly bake the exterior crust of the Arabic-style bread.
Still another object of the invention is to provide a means for allowing regulated venting of the interior of the oven, both as a means for controlling the temperature of the oven and as a means of allowing moisture to escape.
Principal features of the invention include an endless, mesh belt, conveyor extending through an elongate oven housing and beyond the ends thereof; a lower burner assembly, comprising spaced apart gas burners mounted to be easily vertically adjusted between the runs of the conveyor and extending from an inlet to the housing to a point beyond the halfway point of the travel of the conveyor within the housing; and a upper burner unit that is mounted for easy vertical adjustment and that has burners extending from a location short of the midway point of the housing to the discharge end of the housing. The upper burner is positioned above the upper run of the conveyor belt and vent holes are provided in insulated side walls of the housing to allow for temperature control and moisture escape. The vent holes are connected, through spaces between the walls to vent at the top of the housing and the amount of heat and moisture allowed to pass through the vents is regulated by slides mounted inside the housing walls and adjustable from the discharge end of the housing.
Additional objects and features of the invention will become apparent from the following detailed description, taken together with the accompanying drawing.
THE DRAWINGS
FIG. 1 is a perspective view taken from above and at one end of the oven of the invention;
FIG. 2, a vertical, longitudinal section, taken on the line 2--2 of FIG. 1;
FIG. 3, a vertical transverse section taken on the line 3--3 of FIG. 1; and
FIG. 4, an enlarged cross-sectional view similar to that of FIG. 3.
DETAILED DESCRIPTION
Referring now to the drawings:
In the illustrated preferred embodiment, the Arabic-style bread oven of the invention is shown generally at 10. As shown, the oven includes a supporting frame made up of interconnected legs 11 with casters 12 thereon, cross braces 13 and 14, and sets of spaced apart side rails 15. Each set of side rails 15 is held apart by three slotted spacers 16, 17 and 18, each of which has a vertical slot therein. In addition, a spacer 19, at the discharge end of the oven, has an elongate longitudinal slot 20 formed therein.
Journals 21 are formed in the spacers 18 and the shaft 22 of a head pulley 23 extends through and is rotatable in the journals. An endless, mesh belt 24 is trained around the head pulley 23 and a tail pulley 25 (FIG. 2) to provide an endless conveyor for the oven. A shaft 26 of the tail pulley 25 extends through the slots 20 of spacers 19 and through blocks 27 that are mounted to reciprocate within grooves provided therefore in the spacers 19. The blocks 27 are threaded onto rods 28, such that the turning of the rods 28 within supports 28a provided therefore on the spacers 19 will reciprocate the blocks. This, moves the pulley 25 towards or away from the pulley 23 to adjust the tension in the conveyor belt 24. Angle irons 29 extend parallel to the rails 15 and are secured to the spacers 16, 17, and 18 by bolts 30 that extend through holes provided therefore in the angle irons 29 and through the elongate slots provided in the spacers. Nuts, not shown, are threaded onto the bolts 30 to secure the angle irons 29 to the spacers. Spaced apart tubes 31 interconnect the angle irons at each side of the oven and a burner 32 is provided in the upper portion of each tube 31. Tubes 31 are interconnected by a line 33, that extends parallel to the angle irons 29, and which is connected to a gas supply line, not shown. The tubes 31 extend between the upper and lower runs of the conveyor belt 24 and are movable up and down with the angle irons, simply by releasing the bolts 30 and sliding them within the elongate slots of the spacers. This allows the burners to be moved up and down with respect to the upper run of the conveyor belt 24 and thus to be movable towards and away from the products carried by the conveyor belt. The lower burners are spaced below the housing and extend from adjacent to the head pulley to a location past the midpoint of the housing.
Each sprocket 35 on the end of shaft 22 is driven by a chain 36 that passes around a sprocket 37 of a gear box 38. The gear box, in turn, is driven by a motor 39 through drive means 40 including a belt 40a that interconnects a pulley 40b on the output shaft of the motor and a pulley 40c of a clutch 40d. Another pulley 40e of the clutch has a belt 40f therearound. Belt 40d also passes around a pulley 40g on the input shaft of the gear box. When the clutch is engaged the motor, which is continuously operating, drives the gear box 38 and the conveyor belt. When the clutch is disengaged the conveyor belt is stopped. By regulating the frequency of energization of the clutch, in conventional fashion, the rate of travel of bread on the conveyor, through the conveyor can be regulated.
Support braces 43-46 are fixed to the rail members 15 and project upwardly therefrom to support an oven housing, shown generally at 50.
The oven housing 50 is of generally rectangular configuration, with exterior side walls 51 and 52, FIG. 3, interconnected by an exterior top wall 53 and interior side walls 54 and 55 and interior top wall 56. An insulating material 57, such as asbestos fills the space between the interior and exterior walls and helps to retain heat within the housing 50. An inlet end wall, FIG. 2, made up of an outer wall 58 and an inner wall 59 with the insulating material 57 therebetween extends from the top of the housing down to a position close to, but spaced slightly above, the upper surface of the conveyor belt 24. Similarly, a discharge wall, made up of an inner wall 61, and an outer wall 62 interconnected by insulating material 63 is provided at the discharge end of the housing and extends downwardly towards the conveyor belt. A flexible, heat retaining flap 64 then projects from the downwardly extending discharge wall to be in engagement with the upper surface of the conveyor belt 24. As will become more apparent, dough formed into the general configuration of the bread loaf desired and in a rather flat condition is placed on the conveyor belt and is carried beneath the inlet wall and into the oven. As the bread is traveled above the burners 32, the heat therefrom acts on the bread to cause it to rise slightly and to bake.
Another burner assembly shown generally at 70, comprises an inlet pipe 71 that extends into the housing 50 through sleeve 72 that is fixed to and carried by support members 73 on top of the housing. A set screw 74 is threaded through sleeve 72 to engage the inlet pipe 71 and to hold it in position. When the set screw 74 is released the pipe 71 can be raised or lowered to allow positioning of the upper burner as will be hereinafter explained. At its lower end, inlet pipe 71 is connected to a central burner pipe 75, which in turn is connected through manifold pipe 76 to burner pipes 77. The pipes 75 and 77 thus extend over the conveyor belt 24 and transversely to the direction of travel of the belt. The distance between the pipes 75 and 77 and the upper surface of the conveyor belt is determined by the positioning of inlet pipe 71 within the sleeve 72.
Bread traveling on the conveyor belt 24 is moved over the lower burners 32 and then is moved beneath burners 78 in the lower surfaces of the burner pipes 75 and 77. This alternate heat application from beneath and then from above the bread contributes greatly to a properly baked loaf of Arabic-style bread.
It is further necessary to a properly baked loaf, however, that the moisture released from the bread loaves during baking be controlled and that the temperature in the oven be rather closely regulated. To allow for such moisture and temperature control, there are provided a plurality of vent stacks 80 that extend upwardly through the exterior and interior top walls 53 and 56, respectively and the insulating material 57 therebetween. The lower ends of the vent stacks open into a chamber 79 formed between the interior top wall 56 and a spaced apart top inner wall 81 that is supported by side inner walls 82 that are spaced from the interior side walls 54 and 55 and that are supported on the side rails 15. End panels 83 at each end of the oven extend from the exterior side walls to the inner walls to seal the chambers formed between the walls.
A row of spaced apart holes 84 is provided through each inner wall and guide flanges 84a and 84b are provided inside the oven and at opposite sides of each row of holes 83 to receive a slide 85. Each slide 85 has a row of spaced holes 85a therethrough, with the spacing between holes 85a being essentially the same as the spacing between holes 84.
Slides 85 are preferably made of flat sheet metal, bent at the end nearest the discharge end of the conveyor to form a handle 86, which handle can be grasped to move the slide within the guide flanges. The positions of the slides 85 determine the alignment of holes 85a with the holes 84 and the extent to which venting of the interior of the oven through holes 85a, holes 84, the chamber 79 and the vent stacks 80. The amount of venting, will, of course, regulate both the amount of moisture in the oven and the temperature. For convenience, a temperature indicating gauge 90 can be mounted on the oven and can be connected in conventional fashion to continually show the interior temperature of the oven.
With the oven of the present invention the Arabic-style bread can be readily baked. The baking temperature and humidity can be controlled to the degree necessary for satisfactory baking and there is no need for expensive and complicated temperature responsive control valve or other such equipment.
Since the inlet end wall extends close to the conveyor belt, (the spacing being just enough to allow a flat loaf of soft bread dough to pass thereunder), very little of the heat rising from the lower burners is lost at the inlet end of the oven. The flap 64, allows the slightly raised and baked loaves of bread to pass out of the oven while retaining most of the heat within the housing. While tbe oven housing does not include any bottom panels, these are not necessary since the rising heat is adequately trapped by the housing.
Although a preferred form of my invention has been herein disclosed, it is to be understood that the present disclosure is by way of example, and that variations are possible without departing from the subject matter coming within the scope of the following claims, which subject matter I regard as my invention.
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An oven for the continuous baking of Arabic bread and the like. An endless mesh conveyor has gas burners adjustably positioned beneath the upper run thereof at the inlet of the oven and for more than one-half the length of the oven and a vertically adjustable overhead gas burner assembly is provided at the tail end of the oven. Venting of the interior of the oven is provided through openings in a side wall and exhaust stacks connected into the opening and extending upwardly from the top of the oven housing.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part of International Patent Application No. PCT/EP2009/056930 filed on Jun. 5, 2009 and claiming priority and benefit of GB Patent Application No. 0811896.0, filed on Jun. 30, 2008, and of U.S. Patent Application No. 61/076,843, filed on Jun. 30, 2008. The entire disclosure of each of the foregoing applications is incorporated herein by reference.
SUMMARY OF THE INVENTION
[0002] The invention relates to delta-sigma modulators and more particularly to a frequency variable filter in a delta-sigma modulator.
BACKGROUND OF THE INVENTION
[0003] Delta-sigma modulators are increasingly used in receivers for mobile communication. Many different standards exist for mobile communication: GSM, UMTS, CDMA2000 etc. Many of these operate at different frequency bands and with different bandwidths. Especially for the receiver part of a mobile telecommunications system this typically means that specific receivers have to be designed for one frequency range and one bandwidth, because of the analogue nature of the received signal. Although it would be possible to completely digitise the analogue signal, this is usually too elaborate for normal applications. It is more efficient to do some analogue filtering first, and then proceed to analogue-to-digital conversion. This is, in principle, what a continuous-time band pass delta-sigma modulator (CT BP DSM) does. The analogue part of the delta-sigma modulator achieves some bandwidth reduction around the centre frequency of interest, and the feedback action of the DSM provides an efficient error reduction, so that at the digital output of the delta-sigma modulator a digital representation of the analogue payload can be expected.
[0004] Unfortunately, analogue filters, such as LC resonators or so called tanks, cannot be easily re-tuned to different frequency bands during operation. US Patent Application Publication No. 2005/0237233 A1 proposes a programmable loop filter for use with a sigma-delta analog-to-digital converter and method for programming the same. The loop filters shown in this document comprise resistor-capacitor networks (RC networks) wherein the values of the resistors and the capacitors can be varied. However, accuracy usually suffers so that an exact frequency selection is difficult to achieve. Moreover, the ranges of variation of variable resistors or capacitors are usually not very large (or else accuracy is further degraded). Thus it appears that the programmable loop filter proposed in U.S. Patent Application Publication No. 2005/0237233 A1 could still be improved. The entire disclosure of U.S. Patent Application Publication No. 2005/0237233 A1 is hereby included by reference into the description.
[0005] U.S. Patent Application Publication 2006/0119491 A1 describes a dual-mode delta-sigma modulator analogue-to-digital converter system and method that supports two modes of operation. The digital converter system includes a selection unit for permitting the high-frequency resonator circuit and the low-frequency resonator circuit to be employed in a first mode of operation. The system also permits the high-frequency resonator circuit and the feed forward path from the final integrator in the high-frequency resonator circuit to the summer (near the DSM input) to be disabled in a second mode of operation. The digital converter system in U.S. Patent Application Publication 2006/0119491 A1 has a time discrete configuration on its analogue side as opposed to a continuous time configuration. The loop filter is a time discrete filter, as well, that does not contain inductances L or capacitances C. Rather, the loop filter is in the form of a digital filter. The entire disclosure of U.S. Patent Application Publication No. 2006/0119491 A1 is hereby included by reference into the description.
[0006] U.S. Pat. No. 6,693,573 discloses a sigma-delta modulator which utilises Micro Electro Mechanical Systemicro electro mechanical system (MEMS) technology coupled with an on-chip LC networks. The MEMS switches of U.S. Pat. No. '573 are used to switch individual ones of capacitors and inductors in and out of the LC network to alter the centre frequency and tuning range of the sigma-delta modulator.
SUMMARY OF THE INVENTION
[0007] The disclosure teaches more flexibility to a continuous-time, band pass delta-sigma modulator regarding its filtering action. It would be desirable to maintain satisfactory tuning accuracy when changing the frequency bands.
[0008] The disclosure provides a delta-sigma modulator with a filter. The filter comprises a filter input, at least two LC resonators, and at least two switches. An input of one of the at least two switches is connected to the filter input and an output \of one of the two switches is connected to a corresponding one of the at least two LC resonators. One of the at least two switches is individually controllable for selectively connecting the corresponding one of the at least two LC resonators with the filter input.
[0009] It will be noted that the delta-sigma modulator of the current disclosure has no switch inside either of the two LC resonators. As, as such, the quality factor Q and noise shaping properties of the delta-sigma modulator are not degraded by series serious resistance of the switches due to the oscillation of the current in the LC resonator.
[0010] The filter (or one of the filters) in a delta-sigma modulator is typically arranged in the forward branch of the delta-sigma modulator, i.e. between the point where the feedback signal is subtracted from the input signal and the quantizer. Other positions within the delta-sigma modulator are possible, for example in the analogue part of the feedback loop. In the former case (filter in the forward branch) the filter input receives the difference between the input signal and the feedback signal. Within the filter, the received signal is passed on to components of the filter.
[0011] Depending on the selected setting of the two switches either the first resonator or the second resonator is connected to the filter input. Typically, the two switches are switched in a toggled fashion so that only one of the first resonator or the second resonator is active and the other(s) is (are) inactive. Each of the at least two switches can be activated by a control signal provided to a control input of the switch.
[0012] Individual ones of the at least two LC resonators can be tuned relatively exactly to a desired tuning frequency, termed a target frequency. It is possible to achieve a large ratio between a selectable one of a high frequency and a low frequency. When switching from one of the LC resonators to another one of the LC resonators, the target frequency is reached virtually immediately, since each of the LC resonators is pre-tuned, thus offering a fast and accurate change of the frequency. There is no need to (slowly) change the tuning frequency by changing e.g. the capacity of a capacitor.
[0013] It will be appreciated that the enumeration of two switches and two resonators is non-exhaustive, i.e. there could be three or more common base/gate transistors and three or more resonators. This extension is within the scope of the corresponding patent claims.
[0014] In an aspect of the disclosure, the switches are common base/gate transistors (CBT/CGT). The use of common base/gate transistors for the switches means that no different technologies are required for the manufacture of the switches compared to the LC resonator circuit. So, for example, the delta-sigma modulator described in this disclosure can be manufactured using any type of semiconductor process. This is in contrast to the teachings of the prior art U.S. Pat. No. '573 which discloses the use of MEMS technology for the manufacture of switches. Thus the manufacturing process required for the sigma-delta modulator of U.S. Pat. No. '573 requires a semiconductor process which is also capable of supporting MEMS technology.
[0015] For activating the common base transistor (bipolar case), the base voltage of the transistor to be activated has to be higher than the base voltage of the other transistor(s), for example by a few hundred mV. This means that the activation state of the common base transistor can be controlled by raising and lowering the base voltage of the common base transistor. The designation “two common base/gate transistor” comprises either one of the following combinations: two common base transistors, two common gate transistors, or one common base transistor and one common gate transistor. A common base transistor has the input at its emitter and the output at its collector. In the delta-sigma modulator described above, the emitter is directly or indirectly connected to the filter input and receives substantially the same signal as the filter input. A transistor that is connected as a common base transistor is well suited for input signals at high frequencies, because its input impedance is relatively low. Another particularity of the common base configuration is the relatively high isolation between the input and the output which reduces feedback from the output back to the input. For this reason, the common base configuration shows a high stability. The above remarks also apply to common gate transistors if a field effect transistor is used instead of a bipolar transistor.
[0016] In an aspect of the present disclosure, the delta-sigma modulator is a continuous time band pass delta-sigma modulator. In this type of delta-sigma modulator the analogue side can be designed with true analogue elements, such as LC resonators or so called tanks. For some frequency ranges and/or nature of the analogue radio frequency signal, such a configuration is more appropriate.
[0017] In one aspect of the disclosure the filter comprises at least two activatable transconductance amplifiers, an input of one of the at least two activatable transconductance amplifiers being connected to a corresponding one of the at least two LC resonators. A transconductance amplifier accepts a voltage at its input and provides a proportional current at its output. Thus, each transconductance amplifier picks up the voltage at its corresponding LC resonator. The corresponding LC resonator itself is driven by a current that flows through the common base/gate transistor mentioned above.
[0018] In another aspect of the disclosure the filter comprises at least two further transconductance amplifiers. The input of the further transconductance amplifiers is connected to a same one of the LC resonator as the input of one of the two transconductance amplifiers. The further transconductance amplifiers bypass a filter section of the filter. The voltage at the LC resonator is picked up by a transconductance amplifier and by a further transconductance amplifier. Depending on which of these two transconductance amplifiers is activated, a proportional current is supplied to a filter section that is immediately downstream of the filter section that comprises the LC resonators, or not, i.e. the filter section situated immediately downstream is bypassed. By bypassing one or more filter section(s) the order of the filter can be changed.
[0019] In another aspect of the disclosure, the at least LC resonators are tuned to different frequency bands so that the delta-sigma modulator can be tuned to two different frequencies. Such a configuration can be employed in a continuous time band pass delta-sigma modulator.
[0020] In one aspect of the disclosure a first one of the at least two LC resonators is integrated on a principal integrated circuit of the delta-sigma modulator and another one of the two LC resonators is provided off-chip.
[0021] In another aspect of the disclosure, the filter further comprises further LC resonators. Individual ones of the individual ones further LC resonators are organised in two or more LC resonator sets. Individual ones of the two or more LC resonator sets are tuned to a different frequency band. The LC resonators that are organised in a particular one of the LC resonator sets are commonly activatable by appropriate common base/gate transistors for ones of the LC resonators. In delta-sigma modulators having two or more cascaded LC resonators, it may be necessary to coordinate the frequency response of the various cascaded LC resonators in order to achieve the desired filtering effect (e.g. centre frequency of the delta-sigma modulator, bandwidth, . . . ). In this case certain pairs or sets of LC resonators need to be activated/deactivated simultaneously, which in turn means that the common base/gate transistors have to be activated/deactivated simultaneously, as well.
[0022] The disclosure also teaches a method for changing the mode of operation of a (continuous time band pass) delta-sigma modulator, comprising toggling an activation condition of at least one LC resonator of a filter within the delta-sigma modulator by controlling a corresponding switch that is connected to an input of the filter and to the LC resonator. The method affords higher flexibility for the control of a delta-sigma modulator. The method can be performed while the delta-sigma modulator is operating and relatively rapid changes of the frequency response of the delta-sigma modulator can be made.
[0023] In an aspect of the disclosure, the switch is a common base/gate transistor.
[0024] In an aspect of the disclosure, toggling an activation condition of a LC resonator further comprises activating or deactivating a corresponding transconductance amplifier that is connected to an output of the LC resonator. Some types of filters in delta-sigma modulators use the addition of electric currents to implement a mathematical “+” function (“plus” function). A transconductance amplifier is useful in these configurations because it converts an input voltage to an output current. Deactivating unused transconductance amplifiers is advisable for obtaining exact results of the addition of electric currents.
[0025] In one aspect of the disclosure, the changing the mode of operation comprises changing a frequency band of the delta-sigma modulator by activating a first one of the LC resonators and deactivating a second one of the LC resonators. The capability of changing the frequency band provides more flexibility to the delta-sigma modulator.
[0026] In one aspect of the disclosure, changing the mode of operation comprises changing the order of the delta-sigma modulator by changing the selection of the activated ones of the LC resonators. By changing the order of the delta-sigma modulator, different transfer characteristics can be selected. For example the noise-shaping behaviour and/or the dynamic range can be adapted to the needs of a currently selected mode of operation. For example, one mode of operation could be directed to capture weak signals, in which case some concession might have to be made regarding signal quality: For example, a voice signal would be understandable, but the voice might be distorted due to bandwidth compression or strong noise. Another exemplary mode of operation could provide high voice quality when the input signal is strong enough. A low filter order usually provides more robustness.
[0027] A reconfigurable delta-sigma modulator as described above can work at one or more frequency ranges and the order of the delta-sigma modulator can be changed. This makes the delta-sigma modulator flexible enough to be used as a part of a receiver for several different communication standards. Mixing (frequency translating) is not necessary (but nevertheless possible) so that problems related to insufficient image suppression and 1/f noise of receivers based on down conversion mixers can be mostly avoided.
[0028] These and other aspects of the disclosure will be apparent from and elucidated with reference to the embodiment(s) described herein after.
DESCRIPTION OF THE FIGURES
[0029] FIG. 1 shows one embodiment of a delta-sigma modulator having selectable LC resonators.
[0030] FIG. 2 shows an embodiment of a filter of a delta-sigma modulator having selectable LC resonators and a variable filter order.
[0031] FIG. 3 shows an embodiment of a delta-sigma modulator with three selectable sets of LC resonators and variable filter order.
[0032] FIG. 4 shows a detail of the LC resonators and their corresponding common base transistors.
[0033] FIG. 5 shows a flow chart of a method for changing a frequency band of a delta-sigma modulator.
[0034] FIG. 6 shows a flow chart of a method for changing the filter order of a delta-sigma modulator.
DETAILED DESCRIPTION OF THE INVENTION
[0035] For a complete understanding of the present invention, reference is now made to the following detailed description taken in conjunction with the Figures.
[0036] It should be appreciated that the various aspects of the invention discussed herein are merely illustrative of the specific ways to make and use the invention and do not therefore limit the scope of invention when taken into consideration with the claims and the following detailed description. It will also be appreciated that features from one embodiment of the invention may be combined with features from another embodiment of the invention.
[0037] The entire disclosure of U.S. Patent Application Publication Nos. 2005/0237233 A1 and 2006/0119491 A1 is hereby incorporated by reference into the description.
[0038] An object of the present system is to improve the flexibility of delta-sigma modulators and/or to reduce the size of multi-frequency receivers that comprise delta-sigma modulators.
[0039] FIG. 1 shows an aspect of a delta-sigma modulator 10 having selectable LC resonators. Delta-sigma modulator (DSM) 10 comprises an input at the left and an output at the right. A DSM input signal first passes a summing point at which a feedback signal is subtracted. The difference signal is passed to a filter input 13 of a filter 12 (dashed box). The details of filter 12 will be described below. A filter output signal is provided at a filter output 14 and passed on to a quantizer Q. The output of the quantizer Q is usually also the output of the delta-sigma modulator 10 . Furthermore, the output of quantizer Q is digital-to-analogue converted by a digital-to-analogue converter DAC and then fed back to the summing point as an analogue feedback signal. The feedback signal line could be connected to (a) further filter input(s) 15 . Furthermore, the feedback line could comprise a filter, delay elements, or other components.
[0040] In the configuration of FIG. 1 the delta-sigma modulator receives the input signal and the feedback signal in a voltage representation. The summer is able to subtract the two voltages to create the filter input signal. Within filter 12 the filter input signal travels from filter input 13 to a transconductance amplifier gm that converts the filter input signal from an electrical voltage representation to an electrical current representation. Instead of a voltage representation of the feedback signal and the DSM input signal a current representation is also possible. The feedback digital-to-analogue converter DAC could then directly produce a corresponding current.
[0041] The output of transconductance amplifier gm is connected to two common base/gate transistors CBT/CGT configurations, in particular to the emitters of bipolar transistors that are present in the CBT/CGT configurations, or to the sources of field effect transistors. Further details will be illustrated and discussed in connection with FIG. 4 . The collector/drain of each common base/gate transistor is connected to a corresponding LC resonator LC 1 - 1 , LC 1 - 2 . The reference signs of the LC resonators indicate by the first digit the number of the cascaded stage, i.e. “1” for both, LC 1 - 1 and LC 1 - 2 . By the second digit the reference signs indicate which set of resonators the LC resonator belongs to, i.e. to the first set in the case of LC 1 - 1 , and to the second set in the case of LC 1 - 2 . Each of the LC resonators LC 1 - 1 and LC 1 - 2 is connected to a transconductance amplifier gm 1 - 6 and gm 2 - 6 . The reference signs for the transconductance amplifiers are organised as follows: The first digit indicates the number of the LC resonator set. The second number indicates the filter order for which the transconductance amplifier has to be activated. The output currents of transconductance amplifiers gm 1 - 6 and gm 2 - 6 are directed to a box 16 which may represent further filter stages (cf. FIG. 2 ) or a simple merging point (ohmic contact) at which the two currents (one of which being typically zero due to deactivation of its corresponding transconductance amplifier gm*- 6 ) are combined to be lead to the filter output 14 . If box 16 contains one or several further filter stages, the further filter input(s) 15 could be connected to box 16 .
[0042] FIG. 2 shows an aspect of a filter of a delta-sigma modulator having selectable LC resonators and a variable filter order. FIG. 2 shows the filter from filter input 13 to filter output 14 . The left part of FIG. 2 is similar to the corresponding part in FIG. 1 . The right part of the filter in FIG. 2 represents a further filter stage that can be bypassed by means of a suitable configuration of transconductance amplifiers. As in FIG. 1 , a connection extends from each one of the two first stage LC resonators LC 1 - 1 and LC 1 - 2 . The connection from LC 1 - 1 splits up into a connection to transconductance amplifier gm 1 - 4 and into a connection to a multiplexer MUX. The connection from LC 1 - 2 splits up into a connection to transconductance amplifier gm 2 - 4 and into a connection to the multiplexer MUX.
[0043] The two transconductance amplifiers gm 1 - 4 and gm 2 - 4 provide for an option to operate the delta-sigma modulator in a fourth order configuration, i.e. with two LC resonators. If for example, the common base/gate transistor belonging to LC 1 - 1 is activated and the transconductance amplifier gm 1 - 4 is activated, then the filter transfer function of the delta-sigma modulator will be determined by the two LC resonators LC 1 - 1 and LC 3 . In that case the common base/gate transistor belonging to LC resonator LC 1 - 2 and the transconductance amplifier gm 2 - 4 should be deactivated. The output voltage of LC resonator LC 3 is passed to the one of the inputs of multiplexer MUX. Multiplexer MUX has to be controlled so that the correct input is selected. By deactivating the left common base/gate transistor, activating the right common base/gate transistor, deactivating transconductance amplifier gm 1 - 4 , and activating transconductance amplifier gm 2 - 4 , a fourth order combination of LC resonators LC 1 - 1 and LC 3 can be set. The selection of a second order filter or a fourth order filter is achieved by activating either the middle input of the multiplexer MUX (fourth order) or one of the upper/lower inputs of the multiplexer MUX (second order), respectively.
[0044] If the delta-sigma modulator is to be operated in a second order mode, then LC resonator LC 3 is not needed and must be bypassed. This is achieved by the two connections 21 and 22 that connect LC 1 - 1 and LC 1 - 2 , respectively, to the multiplexer MUX. In the second order DSM case the two transconductance amplifiers gm 1 - 4 and gm 2 - 4 are deactivated. The appropriate input of multiplexer MUX has to be selected in accordance with the activation state of the common base/gate transistors.
[0045] FIG. 3 shows an aspect of a filter of a delta-sigma modulator with three selectable sets of LC resonators and variable filter order. Compared to the embodiments shown in FIGS. 1 and 2 , the embodiment of FIG. 3 has been augmented to support at least three frequency bands and a selection between a fourth order DSM and a sixth order DSM. An analogue radio frequency signal ARF is supplied to the input of the delta-sigma modulator and converted from voltage representation to current representation by transconductance amplifier gm. Current summing is performed downstream of transconductance amplifier gm. The other electrical current to be added is the negative feedback current and here provided by a digital-to-analogue converter DAC, which may also take care of the inversion of the feedback current.
[0046] The resulting difference current is passed to an array of common base/gate transistors CBTs/CGTs (cf. FIG. 4 ). Depending on the activation state of the common base/gate transistors in the CBTs/CGTs array, one of the three LC resonators LC 1 - 1 , LC 1 - 2 , and LC 1 - 3 is activated, i.e. the difference current flows through the resonator and provokes a certain voltage at the resonator which is a function of the difference current and the transfer function of the resonator. The resonator output voltage is tapped by six transconductance amplifiers gm 1 - 6 , gm 1 - 4 , gm 2 - 6 , gm 2 - 4 , gm 3 - 6 , gm 3 - 4 , only one of which usually being activated at a time.
[0047] Within the six transconductance amplifiers gm 1 - 6 , gm 1 - 4 , gm 2 - 6 , gm 2 - 4 , gm 3 - 6 , gm 3 - 4 two groups can be distinguished. The first group comprises transconductance amplifiers gm 1 - 6 , gm 2 - 6 , and gm 3 - 6 which are the transconductance amplifiers, one of which is used for operating the delta-sigma modulator in sixth order mode. The second group comprises transconductance amplifiers gm 1 - 4 , gm 2 - 4 , and gm 3 - 4 ; one of these is used when the delta-sigma modulator is operated in fourth order mode. The transconductance amplifiers of the first group (sixth order mode) provide their output currents to a busbar-like structure that is arranged upstream of a common base/gate transistor array of the second stage of the filter, comprising the LC resonators LC 2 - 1 , LC 2 - 2 , and LC 2 - 3 . The busbar-like structure provides for current summation of electrical currents. The second stage comprises three transconductance amplifiers which also bear the reference signs gm 1 - 6 , gm 2 - 6 , and gm 3 - 6 . These transconductance amplifiers provide their output currents to a second busbar-structure that is arranged upstream of a common base/gate transistor array of the third stage of the filter, comprising the LC resonators LC 3 - 1 , LC 3 - 2 , and LC 3 - 3 . The second busbar-like structure is also fed by the second group of transconductance amplifiers gm 1 - 4 , gm 2 - 4 , and gm 3 - 4 .
[0048] The filter shown in FIG. 3 can be operated by choosing one of the following operating modes:
[0000]
filter
reson.
1 st stage
2 nd stage
3 rd stage
transconductance
order
set
CBTs/CGTs
CBTs/CGTs
CBTs/CGTs
amplifiers activated
4
1
1 st transistor
deactivated
1 st transistor
gm1-4
4
2
2 nd transistor
deactivated
2 nd transistor
gm2-4
4
3
3 rd transistor
deactivated
3 rd transistor
gm3-4
6
1
1 st transistor
1 st transistor
1 st transistor
gm1-6 (both amps.)
6
2
2 nd transistor
2 nd transistor
2 nd transistor
gm2-6 (both amps.)
6
3
3 rd transistor
3 rd transistor
3 rd transistor
gm3-6 (both amps.)
[0049] From the third stage of resonators connections lead to a multiplexer MUX. The input selection is based on whether the first, the second, or the third set of resonators is selected. The output of multiplexer MUX is connected to the quantizer Q of the delta-sigma modulator. As before, the delta-sigma output is used as a feedback signal which is generated by a digital-to-analogue convertor DAC. The feedback line also provides further filter inputs 15 .
[0050] A decimator DEC is provided at the output of the delta-sigma modulator for providing a decimated digital output.
[0051] FIG. 4 shows a detail of the LC resonators and their corresponding common base transistors. In the upper part of FIG. 4 , three LC resonators LC 1 - 1 , LC 1 - 2 , and LC 1 - 3 are illustrated. Each of the LC resonators comprises a adjustable capacitor or a pair of adjustable capacitors, an inductor or a pair of inductors, and a centre tap connected to the supply voltage VCC. An input current is supplied via two terminals I in+ and I in− to an array of common base/gate transistors CBT/CGT. Reference is made to the first of the resonators LC 1 - 1 . The input current terminals I in+ and I in− are connected to the emitter of one of a pair of common base/gate transistors CBT/CGT, respectively. The collector of the common base/gate transistors CBT/CGT is connected to one of the terminals of LC resonator LC 1 - 1 . Each of the common base/gate transistors CBT/CGT is controllable by varying the voltage between the base/gate and the emitter (drain) of the transistor. This is achieved by supplying a control signal to terminal EN 1 which is connected to the bases of both common base transistors that are in charge of LC resonator LC 1 - 1 .
[0052] When the voltage between the base and the emitter of the two common base transistors is sufficiently high, the transistor passes into a conducting or amplifying state. Thus the input current I in is supplied to the resonator LC 1 - 1 . A voltage that is filtered by the LC resonator LC 1 - 1 can be obtained at the terminals V out1+ and V out− which are connected to a transconductance amplifier (not shown in FIG. 4 ).
[0053] The common base/gate transistors shown in FIG. 4 could be part of a cascode transistor arrangement. A cascode is an amplifier having a transconductance amplifier (first stage) and a current buffer (second stage). A cascode has high input-output isolation, high input impedance, high output impedance, high gain, and/or high bandwidth. In a cascode the Miller effect is reduced or even eliminated so that the cascode is well suited for high frequency applications. The other part of the cascode, i.e. the transconductance amplifier is not shown in FIG. 4 , but one of them could be connected to one of the input current terminals I in , each.
[0054] For the resonators of the second set and the third set an analogous description can be made. The activation of the resonator of the second set is controlled by applying an appropriate voltage to terminal EN 2 , and the activation of the resonator of the third set is controlled by applying an appropriate voltage to terminal EN 3 . The output voltage terminals are V out2+ , V out2− , and V out3+ , V out3− , respectively.
[0055] FIG. 5 shows a flow chart of a method for changing a frequency band of a delta-sigma modulator. The method starts at action 50 . The currently selected frequency band is determined in action 52 . The new frequency band, i.e. the selected frequency band is determined in action 53 . In action 54 the common base/gate transistors for the currently selected frequency band are deactivated. Action 55 is performed substantially synchronously to action 54 . In action 55 the transconductance amplifiers for the currently selected frequency band are deactivated. The common base/gate transistor(s) for the new frequency band is/are activated in action 56 and the transconductance amplifier(s) for the new frequency band is/are activated in action 57 . The delta-sigma modulator has thus performed a change of the frequency band and the method ends at action 58 .
[0056] FIG. 6 shows a flow chart of a method for changing the filter order of a delta-sigma modulator. The method starts at action 61 . The currently selected mode of the delta-sigma modulator is determined in action 63 . The activated ones of the transconductance amplifiers are determined in action 64 . Then, in action 65 , the required transconductance amplifiers for the selected mode of the delta-sigma modulator are determined. This may be done by querying a configuration file CFG FILE 66 . Subsequently, those transconductance amplifiers that are not needed for the selected operating mode are deactivated in action 67 . In parallel action 68 , those transconductance amplifiers that are required for the newly selected mode, but not yet activated, are activated. The method then ends at action 69 .
[0057] While various embodiments of the present invention have been described above, it should be understood that they have been presented by way of example, and not limitation. It will be apparent to persons skilled in the relevant arts that various changes in form and detail can be made therein without departing from the scope of the invention. For example, in addition to using hardware (e.g., within or coupled to a Central Processing Unit (“CPU”), microprocessor, microcontroller, digital signal processor, processor core, System on Chip (“SOC”), or any other device), implementations may also be embodied in software (e.g., computer readable code, program code, and/or instructions disposed in any form, such as source, object or machine language) disposed, for example, in a computer usable (e.g., readable) medium configured to store the software. Such software can enable, for example, the function, fabrication, modelling, simulation, description and/or testing of the apparatus and methods described herein. For example, this can be accomplished through the use of general programming languages (e.g., C, C++), hardware description languages (HDL) including Verilog HDL, Verilog AMS, VHDL, and so on, or other available programs. Such software can be disposed in any known computer usable medium such as semiconductor, magnetic disk, or optical disc (e.g., CD-ROM, DVD-ROM, etc.). The software can also be disposed as a computer data signal embodied in a computer usable (e.g., readable) transmission medium (e.g., carrier wave or any other medium including digital, optical, or analog-based medium). Embodiments of the present invention may include methods of providing the apparatus described herein by providing software describing the apparatus and subsequently transmitting the software as a computer data signal over a communication network including the Internet and intranets.
[0058] Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims. In the claims, the word “comprising” does not exclude other elements or steps, and the indefinite article “a” or “an” does not exclude a plurality. A single processor or other unit may fulfil the functions of several items recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.
[0059] It is understood that the apparatus and method described herein may be included in a semiconductor intellectual property core, such as a microprocessor core (e.g., embodied in HDL) and transformed to hardware in the production of integrated circuits. Additionally, the apparatus and methods described herein may be embodied as a combination of hardware and software. Thus, the present invention should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims and their equivalents.
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A delta-sigma modulator is disclosed which has a filter comprising a filter input, two LC resonators (LC 1 - 1 , LC 1 - 2 ), and two switches (CBT/CGT). An input of each one of the two switches is connected to the filter input and a corresponding output of each one of the two switches is connected to a corresponding one of said LC resonators. Each one of the two switches is individually controllable for selectively connecting the corresponding one of the LC resonators with the filter input. The invention also relates to a method for changing the mode of operation of a delta-sigma modulator.
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BACKGROUND OF THE DISCLOSURE
This disclosure is directed to systems for measuring the dielectric constant of well bore fluids which provide an output indicative of the dielectric constant, and hence an indication of oil and water mixture in a well borehole. In drilling a well, formation fluids which are a mixture of oil and water are often produced. After the well has been drilled and during production, it may again produce a mixture of oil and water. This mixture may change over a period of time so that measurement of the ratio of oil and water is important to proper production of the well. In summary, an important characteristic is the ratio or mixture of oil and water. The present apparatus takes advantage of the differences in dielectric constant of the mixture of the two constituents in the well borehole fluids. Water has a dielectric constant about twenty times greater than that of oil.
The present apparatus utilizes quite high frequencies which are coupled through coaxial lines with appropriately connected terminations to thereby couple electrically the fluid into the line for obtaining transmission measurements. Substantially, the response is independent of temperature and is a response from a relatively large volume of fluid to avoid localized irregularities. It utilizes conductors of coaxial construction extending from a sonde into the fluid in one embodiment, or submerged in fluid within the sonde so that the mixture of produced oil and water from the well can be measured. It utilizes a coaxial cable, and in particular two lengths thereof, the two lengths of cable being mechanically coupled by means of an appropriately constructed window further having a coupling relationship through the window. In other words, the transmitted signal is coupled through the window into the liquid which submerges the immediate vicinity of the sonde. The output can be read at a particular terminal in the form of an output voltage. The output voltage can be converted by means of relatively linear calibrations so that the output is a correctly indicated measure of percent of oil and water in the well bore fluids. To this end, the equipment preferably utilizes a microwave generator which serves as a transmitter and appropriate lengths of coaxial cable terminating at an appropriate matched load or resistance together with a signal detection circuit.
The present apparatus can be used in a continuous wave (CW) mode so that it is able to provide a continual reading as the supportive sonde is moved along the well borehole. The output can be calibrated relative to known mixtures so that output voltages relative to the mixtures can be calibrated to read either in volts or directly in percent mixture of water and oil.
BRIEF SUMMARY OF THE PRESENT APPARATUS
This apparatus is summarized as a coaxial cable system connected as an antenna and includes a high frequency signal generator, a segment of cable, a mixer, and another segment of cable which terminates at a suitable and preferably matched resistive load. This reduces the standing waves on the cable system. The two sections of cable may be joined together and a window cut in the shield of each cable. The window has a specified length, and is further defined by gaps of a specified width in the shields around the two sections of cable. This permits the surrounding fluid to move into close proximity to the window and thereby form a capacitive coupling medium which is related to the dielectric properties of the medium, and that in turn is dependent on the effective bulk dielectric constant of the oil and water mixture.
BRIEF DESCRIPTION OF THE DRAWINGS
So that the manner in which the above recited features, advantages and objects of the present invention are attained and can be understood in detail, more particular description of the invention, briefly summarized above, may be had by reference to the embodiments thereof which are illustrated in the appended drawings.
It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.
FIG. 1 shows a sonde supported on a logging cable in a well borehole in an oil and water mixture for measuring the dielectric thereof to determine the relative concentration of water and oil and the mixture;
FIG. 2 shows a schematic of the generator and coaxial cable system arranged for operation of the present sensor system;
FIG. 3 of the drawings is a sectional view along the line 3--3 of FIG. 2 showing signal interconnection of the two coaxial cables with windows cut therein and a defined gap for interjecting surrounding fluid into the system for measurement;
FIG. 4 is a plot of dielectric constant versus output voltage to show variations in oil and water mixture encoded by a change in voltage; and
FIG. 5 is a drawing of an enclosed version of the invention in conjunction with a formation testing apparatus to sample formation fluids.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Attention is now directed to FIG. 1 of the drawings which shows the dielectric measuring apparatus 10 of the present disclosure positioned in a well borehole 12, typically uncased, but equally useful for a cased well, wherein the apparatus is placed within a sonde 14 suspended on a logging cable 16 and completely submerged in oil, water or a mixture thereof identified at 18. The logging cable 16 extends to the surface and passes over a sheave and is spooled on a large supply reel or drum 22. There are one or more electrical conductors in the armored logging cable which connect from the sonde 14 to a CPU 24 which operates to execute and carry out the various and sundry activities which are required of the equipment. Control signals are sent down the logging cable and data is received up the logging cable. The output is provided from the CPU 24 to a recorder 26. The data of interest is recorded, and typically it is helpful to furnish this data as a function of depth. Depth is indicated by an electrical or mechanical depth measuring apparatus 28 which typically measures cable length dependent on travel of the cable 16 over the sheave. Typically, the sonde 14 is lowered into the well and is submerged at a selected depth. The depth is noted. Measurements of the liquid accumulating in the well are taken and are provided for surface inspection. A typical output from the present apparatus indicates that the liquid accumulated in the well is a specific percentage of oil and water in ratios ranging from pure oil to pure water and percentages in between.
The present apparatus is relatively small in the sense that the antenna which is exposed to the liquid 18 is quite small. It has been shown in FIG. 1 to be enclosed in a sonde chamber perforated to allow free passage of borehole fluids, or external of the sonde 14. The apparatus can be on the exterior, but for protection against banging during transit along the well borehole, the antenna is placed within a chamber in the sonde which is exposed to well fluids. In any event, the dielectric sensing mechanism is arranged so that an antenna system is included at a location which is exposed to the mixture of oil and water in the well borehole.
Going now to FIG. 2 of the drawings, equipment located in the sonde includes an adjustable frequency AC signal generator 30 which forms an output on a coaxial cable 32. The cable 32 connects to a mixer 34 which has an additional output to a voltage measuring device 36. In addition, another port of the mixer 34 connects with a second coaxial cable 38 and that extends to the cable load 40. The coaxial cables 32 and 38 are joined together and form an antenna system which integrates the well borehole fluids as part of the dielectric as will be described. The operation of the system shown in FIG. 2 is better understood when scale values are placed thereon.
As a generalization, the generator 30 is a frequency adjustable oscillator which forms an output signal at a fixed voltage. A low level or signal voltage is all that is needed. The generator 30 preferably forms an output signal in the megahertz range. The frequency can be quite high, even up into the range of a few gigahertz. In a representative system, the generator can operate at 2.5 GHz. For operation at this frequency level, the output is provided to the coaxial cable 32 which has a characteristic impedance. To this end, the termination 40 matches the characteristic impedance so that a standing wave is not formed on reflection from the termination 40. Consider a typical coaxial cable. Utilizing cable having a Teflon dielectric wherein the cable may be described as semi-rigid and the cable segments 32 and 38 are each about one meter in length, they have common diameters of about 0.141 inches, and the cables 32 and 38 are joined in the fashion shown in FIG. 3. The cables are identical, typically being obtained from the same supply spool. Both of the cables have a central conductor which is one or multiple strands which is surrounded by a dielectric sleeve of cylindrical construction. The outer sheath of the cable is typically an extruded solid copper tubular shield which is formed into a ground screen or shield. The outer sheath may also be made of a corrosion-resistant alloy plated with copper on the inside surface to provide high electrical conductivity. Here, the cable 32 has the sheath 40 while the cable 38 has the sheath 42. The two sheaths are soldered together at 44 where a fillet of solder is placed between them. The fillet has a length which will be described and has a width which is sufficient to bind the two cables together and is provided only for mechanical stability. Both sheaths 40 and 42 have small lengthwise parallel windows cut therein, the windows being identified at 46 and 48. The two windows cooperate to define a dielectric gap between the two cables which is filled with the liquid in the well borehole, and liquid in that particular gap is measured. In other words, the windows formed in the two cables introduce the dielectric of the liquid into the system.
The cuts which are formed define a lengthwise window. The length of the windows is related to the frequency of the signal generator, and has an upper limit which is determined by the frequency and signal propagation velocity along the cable. Thus, the cable window L is given by c/[2f(K) 1/2 ]. The symbol c is the velocity of light while f is the frequency of the oscillator 30. K is the dielectric constant of the cable insulator. This defines a maximum or upper limit for the window length. If Teflon is the dielectric and the generator frequency is 2.5 gigahertz, the window length is typically about 4 centimeters. The windows 46 and 48 have a limited width which is generally determined by the need to minimize variations in the cable characteristic impedance that enable proper or acceptable internal reflections versus increases in signal coupling when the window is wider. An acceptable compromise between these two contradictory factors is a width which is about one tenth the internal circumference of the insulator sleeve within the cable.
When the cables 32 and 38 are joined in the fashion shown, coupling between the two cables occurs by electric field and magnetic field interaction between the two cables. The measure of coupling through the respective windows is in part determined by the impedance of the gap between the two windows. That gap in turn is dependent on the physical dimensions of the gap and also on the dielectric constant of the materials in the gap. As a generalization, coupling through the respective windows from one cable to the other may be by electric field coupling in which event the coupled system incorporating the surrounding well borehole fluids is especially sensitive to the dielectric constant of the materials that are in the gap. The gap is defined as the cable to cable measure across the full width of the two windows considered jointly. The windows, however, refer to the width of the cuts in the outer sheath or shield of the cables. An acceptable ratio is a window to gap width ratio of about 1:3. The coupling through the two windows incorporates the gap as mentioned and the material that is in that gap so that the liquid becomes a part of the circuit. The equivalent circuit involved in this two window and gap arrangement involves a relationship where the output voltage is given by a relationship generally being V=G V o fZ o . In the foregoing, G incorporates coupling capacitance and other geometrical variables that are fixed for a particular sized assembly, and V o is the generator output voltage, Z o is the cable characteristic impedance, and f is the frequency of the generator. It will be observed that the output voltage is generally a linear function of frequency; as frequency increases, the output voltage increases. The constant G may be computed from the dimensions of the apparatus, but is preferably determined by calibration to compensate for typical small manufacturing variations.
Utilizing the foregoing arrangement, and operating at frequencies even as high as 5 GHz, output voltages have been observed that are sufficiently sized to be measurable. By contrast, lower frequencies can be used, even in the range of 200 MHz with a reduction in measurement accuracy. Consider a particular example which is set out in FIG. 4. There, the dielectric can be as much as about 81 which is the dielectric constant of pure water. Oil has a much lower dielectric constant of about 4 so that the 100 percent oil data point is also shown. The midpoint further shows a fifty percent mixture of oil and water. The output voltage (measured in microvolts) is proportionate to dielectric constant and thus provides the desired measured result. The operating frequency which can be as high as 5 GHz; the data of FIG. 4 was obtained at 2.5 GHz. It is generally preferable to operate at higher frequencies because they are less sensitive to salt dependent changes where substantial quantities of salt are dissolved in the water. Of course, there are other impurities which may be carried in the liquid and they may have a different kind of impact on the measured data.
The present apparatus can be used to obtain an indication of percent of oil and water mixture which is non-linearly proportionate to output voltage. The voltage is simply measured and the output data provides the appropriate indication according to calibration of the sort shown in FIG. 4 for a particular frequency of operation. By use of calibration charts such as this, changes in scale values such as operating frequency, changes in cable window and gap size, changes in cable characteristic impedance, and the like can be accommodated quite easily. Moreover, the system is relatively simple in that it has no moving parts and provides a substantially instantaneous reading which quickly reflects changes in the percent mixture.
The cable gap can be flush mounted on the sonde also. Physical bending of the coaxial cables is permitted so long as the windows preferably lie in a common plane arrangement parallel to one another and are generally straight. Moreover, the sensitive region which is the window is best exposed to large volumes of fluid; spot irregularities are thus reduced, or even eliminated. Furthermore, the exposure of the cable with the windows permits rapid readings to be obtained as the sonde moves along the well borehole at great speed or at no speed. That is, the sonde can be stationary if desired. In this regard, the present invention may also be installed in formation tester logging tools as shown in FIG. 5. During exploratory logging of freshly-drilled boreholes, it is often desirable to draw samples of connate fluid from a rock formation of interest intersected by the borehole. In a known fashion, a pad is forced against the borehole wall to provide a fluid-tight seal, and a mechanical pump draws a sample of fluid to enable the fluid properties (e.g., pressure) to be measured. In FIG. 5, the fluid is pumped between coupled transmission lines as indicated by the arrows depicting fluid flow within the body of the testing tool while the dielectric properties are measured as described with respect to FIGS. 2 and 3. Component numerals and functions in FIG. 5 correspond to FIG. 2. This method provides a novel means to directly determine the oil/water concentrations of selected intervals of rock formations.
While the foregoing is directed to the preferred embodiment, the scope thereof is determined by the claims which follow.
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A method and apparatus for measuring a mixture of oil and water in a well borehole is set forth. The measurement is a measurement of mixture dielectric constant obtained by exposing a pair of windows to the mixture of well borehole liquids. Each window is formed in coaxial cable portions having cuts in the respective surrounding ground sheaths thereof wherein the sheaths are positioned so that the windows are adjacent and parallel. The two windows form a gap which may be approximately three times wider than the windows formed in the sheath. A signal generator drives the system at a specified voltage and frequency, and changes in signal coupled between the cables are measured where the changes derive from changes in the dielectric constant of the mixture of oil and water coupled in the circuit.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a filing under 35 U.S.C. § 371 and claims priority to international patent application number PCT/EP2007/002588 filed Mar. 23, 2007, published on Oct. 4, 2007, as WO 2007/110203, which claims priority to patent application number 0606144.4 filed in Great Britain on Mar. 28, 2006.
FIELD OF THE INVENTION
[0002] The present invention relates to an automated crossflow filtration method and system for separating a component of interest from one or more other components in a solution. The invention is of use in the field of protein separations, where specific proteins must be separated and purified from cell lysates and cultures. The invention finds particular utility in concentrating proteins which are present at low concentrations in a solution containing one or more components.
BACKGROUND OF THE INVENTION
[0003] Separation of target molecules is of great commercial interest in the chemical and biotechnological fields, such as the production of novel biological drugs and diagnostic reagents. Furthermore, the isolation and purification of proteins is of great significance due to advances in the field of proteomics, wherein the function of proteins expressed by the human genome is studied. Proteins of interest are often present at very low concentrations within a biological sample and so it is very important to develop isolation and separation techniques which can handle low volumes of such samples with minimal wastage. This is particularly true in research laboratories which are concerned with the early stage purification and characterisation of proteins which are present in low concentrations of source material.
[0004] In general, proteins are produced in cell culture, where they are either located intracellularly or secreted into the surrounding culture media. Since the cell lines used are living organisms, they must be fed with a complex growth medium, containing sugars, amino acids, growth factors, etc. Separation and purification of a desired protein from the complex mixture of nutrients and cellular by-products, to a level sufficient for characterisation, poses a formidable challenge.
[0005] Semi-permeable membrane filtration is often used in the purification of proteins, microfiltration and ultrafiltration being the most commonly practised techniques. Microfiltration membranes exhibit permselective pores ranging in diameter from between 0.01 and 10 μm. Micro-filtration is defined as a low pressure membrane filtration process which removes suspended solids and colloids generally larger than 0.1 μm in diameter. Such processes can be used to separate particles or microbes that can be seen with the aid of a microscope such as cells, macrophage, large virus particles and cellular debris.
[0006] Ultra-filtration membranes are characterized by pore sizes which enable them to retain macromolecules having a molecular weight ranging between 500 and 1,000,000 daltons, and thus are often used for concentrating proteins. Ultra-filtration is a low-pressure membrane filtration process which separates solutes up to 0.1 μm in size. Thus, for example, a solute of molecular size significantly greater than that of the solvent molecule can be removed from the solvent by the application of a hydraulic pressure, which forces only the solvent to flow through a suitable membrane (usually one having a pore size in the range of 0.001 to 0.1 μm). Ultra-filtration is capable of removing bacteria and viruses from a solution.
[0007] Many automated systems exist for the separation of proteins using such ultra- and microfiltration membranes (e.g. GE Healthcare Life Sciences, Uppsala, Sweden).
[0008] Crossflow filtration (sometimes referred to a ‘tangential flow filtration’) systems are widely used in industry; typical examples include manufacturing process separations, waste treatment plants and water purification systems where they extend the lifetime of filtration membranes by removing and preventing the build up of contaminants (e.g. WO 2005/081627) and promote consistency of the filtration process with time.
[0009] The most commonly used crossflow membrane processes are microfiltration and ultrafiltration. These processes are pressure driven and depend upon the ‘membrane flux’, defined as the flow volume over time per unit area of membrane, across the microfiltration or ultrafiltration membrane. At low pressures, the transmembrane flux is proportional to pressure. Thus by varying the transmembrane pressure difference driving force and average pore diameter, the membrane may serve as a selective barrier by permitting certain components of a mixture to pass through while retaining others. This results in two phases, the permeate and retentate phases, each of which is enriched in one or more of the components of the mixture.
[0010] Crossflow filtration systems are commercially available from a number of manufacturers for a range of applications, including the separation of biological materials (e.g. GE Infrastructure, Water and Process Technologies, Fairfield, Conn., USA; Millipore, Billerica, M, USA; SciLog, Wis., USA; GEA filtration, MG Technologies, Frankfurt, Germany).
[0011] However, one major disadvantage of existing systems which are used to purify biological materials is that they require relatively large volumes of sample (typically >25 mls), due to the internal configuration of the pumps, and have significant ‘dead volumes’. This can be extremely wasteful of material which, in the case of proteins which are often only present in relatively low concentrations in biological samples, can be very expensive and resource consuming.
[0012] Another disadvantage associated with conventional crossflow systems is that of foaming, caused by air within the system, which also leads to losses of material.
[0013] U.S. Pat. No. 5,935,437 describes a single-use, manually operated crossflow filtration system for preparing plasma samples from patients' blood during surgery. The system disclosed is capable of handling a small volume (e.g. less than 10 ml of blood) under aseptic conditions. While this system is clearly suitable for use in an operating theatre, it is not suitable for use in a research or industrial laboratory where users require automated systems which are robust, reliable, environmentally regulated and precise.
[0014] Spectrum Labs (Spectrum Laboratories Inc., USA) provide the components for making a simple cross flow separation system for use in processing small volumes of samples containing biological materials. The disposable MICROKROS® modules comprise hollow fibre membranes in a polysulfone housing. These modules can be operated manually using conventional syringes to handle volumes as low as 2 ml of sample. Alternatively, the modules can be used with a peristaltic pump, such as the Spectrum MICROKROS® System, to process sample volumes ranging from 10 to 200 ml. Although this system can accommodate small volumes of solution (i.e. from 10 to 200 ml), the precision of separation can be variable as the system is controlled by a peristaltic pump.
[0015] There is therefore a need within the research communities of the chemical and biotechnological industries for an automated crossflow filtration system which can handle small volumes of solution, under carefully regulated conditions, with a high level of precision and minimal wastage of sample. Further cost savings could be achieved if it were possible to wash and reuse the membranes employed in such a system.
[0016] The present invention addresses these problems and provides a method and system for separating a first component of interest from one or more components in a solution. To improve consistency and efficiency, the system of the invention may be under the control of a computer software programme.
SUMMARY OF THE INVENTION
[0017] In a first aspect of the invention, there is provided an automated crossflow filtration method for separating a component of interest from one or more other components in 50 ml or less of a solution comprising the steps of
i) transferring said solution from a sample container into a receiving chamber of a first pump, said chamber being in fluid communication via one or more flow-directing valves with a receiving chamber of a second pump, wherein both said chambers have a moveable wall for altering the volume of the chamber; ii) passing the solution through a filter unit, said filter unit comprising
i. a first inlet and a second inlet in fluid communication with each other ii. an outlet iii. a filtration membrane separating the inlets from the outlet, by simultaneously driving the solution from the chamber of the first pump through the filtration membrane and aspirating the first retentate produced into the chamber of said second pump;
iii) collecting the first permeate produced which has passed through the filtration membrane; iv) reversing the direction of flow across the filtration membrane by simultaneously driving the first retentate from the chamber of the second pump back through the filter unit and the filtration membrane and aspirating the second retentate produced into the chamber of the first pump; v) collecting the second permeate produced and/or the second retentate;
wherein a predetermined membrane flux or pressure is maintained across the filtration membrane by controlling the differential rate of movement of the wall in the first and second receiving chamber of the first and second pump.
[0026] A component of interest may be chemical compound, or a biological entity or a biological molecule. Examples of chemical compounds include naturally occurring and synthetic compounds such as drugs and therapeutic agents. Biological entities include, for instance, cells (e.g. blood cells and animal cells), microbes (e.g. bacteria and fungi), and sub-cellular particles (e.g. mitochondria, viruses etc). Biological molecules may include proteins, peptides, polynucleotides, and polysaccharides. The method is of particular utility in separating proteins and in concentrating proteins which are present at low concentrations in a solution containing one or more components.
[0027] Membranes may include ultrafiltration membranes, affinity membranes (i.e. membranes which are derivitized to bind to ligands in a specific or non-specific manner), microfiltration membranes, ion exchange resins and reverse phase membranes. Such membranes are well known in the art and are available from a range of suppliers (e.g. GE Healthcare Life Sciences, Sweden; Sartorius AG; Germany; Meissner Inc., USA). The membranes may be of flat or hollow configuration.
[0028] A second aspect of the invention relates an automated crossflow filtration system for separating a component of interest from one or more other components in 50 ml or less of a solution comprising
i) a first pump having a receiving chamber and a moveable wall for altering the volume of said chamber, said moveable wall being operable by a first drive motor, the chamber being in fluid communication via a first flow-directing valve with a sample container and a first inlet of a filter unit; ii) said filter unit comprising
a. a first inlet and a second inlet in fluid communication with each other b. an outlet c. a filtration membrane separating the inlets from the outlet,
iii) the second inlet of the filter unit being in fluid communication via a second flow-directing valve with a receiving chamber of a second pump; iv) said second pump comprising said receiving chamber and a moveable wall for altering the volume of the chamber, said moveable wall being operable by a second drive motor; v) the first flow-directing valve comprising one or more ports enabling fluid communication of the chamber of the first pump with one or more containers for aspiration of solution therefrom and/or the collection of retentate therein; optionally, enabling the aspiration of buffer therefrom; vi) the second flow-directing valve comprising one or more ports enabling fluid communication of the chamber of the second pump with a plurality of containers for aspiration of washing fluid therefrom and/or collection of retentate or waste therein;
characterised in that a predetermined membrane flux or pressure is maintained across the filtration membrane by controlling the differential rate of movement of the wall in the first and second receiving chamber of the first and second pump.
[0038] A third aspect of the invention relates to a computer programme arranged to perform the method of the invention.
[0039] A fourth aspect of the invention relates to a data carrier in which the computer programme is stored.
[0040] Further features and advantages of the invention will become apparent from the following description of preferred embodiments of the invention, given by way of example only, which is made with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0041] The transverse section in FIG. 1 shows one embodiment of the invention in which the crossflow filtration system has a series of filter units which each comprise a microfiltration membrane.
[0042] FIG. 2 depicts a transverse section of one embodiment of the invention in which the crossflow filtration system has a series of filter units which each comprise an ultrafiltration membrane.
[0043] FIG. 3 illustrates, in transverse section, an embodiment of the invention in which the crossflow filtration system has a filter unit containing a microfiltration membrane, a filter unit comprising an ultrafiltration membrane, and an affinity membrane.
DETAILED DESCRIPTION OF THE INVENTION
[0044] One embodiment of an automated crossflow system 1 according to the invention, utilising a microfiltration membrane is shown in transverse section in FIG. 1 . The system can be used to separate components present in a solution, such as are commonly found in biological samples. For example, depending upon the pore size of the membrane used, cells (such as blood cells) can be washed with buffers prior to lysis to remove contaminants, cellular debris can be separated from soluble materials, and/or proteins can be purified for characterisation.
[0045] The system 1 comprises a first pump 10 and second pump 20 which are in fluid connection with one another through one or more filter units 30 , 40 , 50 , 60 connected through a first flow-directing valve 70 and a second flow directing valve 80 . Each pump comprises a receiving chamber 12 , 22 and a moveable wall 14 , 24 connected through a drive shaft 16 , 26 to independent drives 18 , 28 . A solution can be drawn into or expulsed from the receiving chamber 12 , 22 by the axial movement of the wall 14 , 24 relative to the body of the pump 10 , 20 (e.g. in the direction of the arrow shown in FIG. 1 ) when the drive 18 , 28 is activated. The walls of the receiving chamber 12 , 22 are made of an inert material, such as glass, ceramics, stainless steel or an appropriate plastic polymer which can withstand high operational pressures and not react with any components within the solution.
[0046] In use, solutions 91 , 92 , 93 , 94 which each comprise a component of interest and one or more other components, are sequentially aspirated from their respective sample containers into the receiving chamber 12 of the first pump 10 by movement of the wall 14 in the opposite direction to the arrow shown in the figure. The use of the system 1 will be described in relation to separating components of interest from a single solution 91 but it will be understood that the system can be used to sequentially separate components from other components within a plurality of solutions (e.g. from solutions 92 , 93 , 94 ).
[0047] The solution 91 is drawn from its sample container into the receiving chamber 12 of the first pump 10 via the flow directing valve 70 by means of tubing 71 . The tubing 71 and valve 70 are made of conventional materials, such as metals or plastics, which do not react with any components in the solution. The valve 70 , comprises one or more ports (not shown) which can be used to allow the valve 70 to act as a filter unit 30 selecting valve and/or an inlet/outlet valve.
[0048] In the first half of the cycle, solution 91 is driven from the receiving chamber 12 of the first pump 10 , by movement of the wall 14 in the direction of the arrow shown in FIG. 1 , through the valve 70 and into the filter unit 30 by means of tubing 76 . The first pump 10 thus controls or regulates the flowrate of ‘feed’ solution 91 (i.e. the solution prior to filtration) moving into and through the filter unit 30 .
[0049] The filter unit 30 comprises a first inlet 32 in fluid communication with a second inlet 34 , the inlets being connected to the first and second flow-directing valves 70 , 80 , respectively, by inert tubing 76 , 86 . The inlets 32 , 34 are separated from an outlet 36 by a membrane 38 within the filter unit 30 which is selectively permeable to the component of interest. The membrane 38 in FIG. 1 is a microfiltration membrane but it will be understood that, depending upon the nature of the separation to be effected, an ultrafiltration membrane could be used. A microfiltration membrane will be chosen which has pore sizes such that the component of interest within the solution will pass through the membrane whereas larger components will be retained by it. The solution passing through the membrane is known as the permeate, while the material retained by the membrane is called the retentate.
[0050] As described above and shown in FIG. 1 , the second pump 20 is in fluid communication with the first pump 10 by means of the first and second flow-directing valves 70 , 80 . The pumps 10 , 20 are independently driven such that the receiving chamber 12 of the first pump 10 empties at a faster rate than the receiving chamber 22 of the second pump 20 fills. The higher speed of the wall 14 in emptying the first chamber 12 compared to the speed of the wall 24 in filling the second chamber 22 creates a permeate flux across the membrane 38 . Thus the permeate flux, which determines the rate of separation of components across the membrane, is controlled by the differential speed of the walls 14 , 24 of the first 12 and second 22 receiving chambers. This permeate flux may be monitored by pressure sensors 101 , 103 . Other sensors ( 102 , 104 , 105 ) may be employed to monitor other physical parameters (e.g. temperature, conductivity, pH, oxygen concentration, ultraviolet light absorption) within the system.
[0051] In the embodiment shown in FIG. 1 , the filter unit 30 contains a microfiltration membrane 38 and permeate passing through the membrane 38 is collected from the outlet 36 as product 111 . The retentate is collected in the receiving chamber 22 of the second pump 20 .
[0052] When the wall 14 reaches the end position of the stroke in emptying the solution 91 from the chamber 12 , the first half of the cycle is complete and the movement of both drives 18 , 28 is reversed. In this half of the cycle, the ‘feed control’ pump (initially the first pump 10 in the first half of the cycle) becomes the retentate control pump and the retentate control pump (the second pump 20 in the first half of the cycle) becomes the feed control pump. The direction of flow is thus reversed such that retentate is driven from the second receiving chamber 22 back into the filter unit 30 and across the membrane 38 to further remove components of interest from the retentate. Once again, the slower speed of filling the retentate control pump (first pump 10 in this phase of the cycle) relative to the speed of emptying the feed control pump (i.e. second pump 20 ) creates a permeate flux across the membrane 38 . The permeate passing through the membrane 38 is collected as further product 111 and the resulting retentate aspirated into the first receiving chamber 12 . In this way, components of interest are sequentially removed from the solution 91 . The cycle can be repeated, either using the same retentate or by aspirating fresh solution 91 into the first chamber 12 (or second chamber 22 ) to maintain the volume of solution within the system by means of the flow-directing valve 70 , 80 at the start of each new stroke. By replenishing the system with fresh solution 91 , 121 in this way, the system is not limited to simply processing volumes equivalent to the volume of the receiving chamber 12 , 22 . At the end of a complete cycle, waste materials can be removed from the system via the second flow-directing valve 80 as waste 124 .
[0053] By means of the flow-directing valves (e.g. 80 ) equipped with inlet/outlet ports, the membrane 38 can be cleaned with washing fluid/buffers 122 , 123 at the end of a complete cycle to remove any contaminants (such as solids, particles, etc) which adsorb to the membrane surface and block the pores. In this way, the operational lifetime of the membrane can be increased and its efficiency maintained.
[0054] It will be understood by the person skilled in the art that other samples 92 , 93 , 94 can be sequentially filtered in a similar manner either through the same filter unit 30 or different filter units 40 , 50 , 60 which either contain the same or different membranes (e.g. one having a different pore size). Following filtration in the filter units 40 , 50 , 60 , permeate can be collected from outlets (see shorter arrows) as product 112 , 113 and 114 . It will also be understood that the system can be used in combination with ultrafiltration membranes, as described below.
[0055] All materials used in the construction of the system which come into contact with the solution, retentate and/or permeate are selected to avoid any chemical interaction and to minimise physical adsorption with the components within the solution. Typically, the walls of the receiving chamber and the valves are made of glass, ceramics or stainless steel and the tubing of an inert plastic polymer.
[0056] FIG. 2 is a transverse section showing a second embodiment of an automated crossflow system 2 according to the invention. This embodiment can be used to ultrafiltrate samples, for example, the system can be used to concentrate particular components present in a sample, such as proteins, for further characterisation.
[0057] The system 2 has a similar configuration to that described in FIG. 1 above. Thus a first pump 110 and second pump 120 are in fluid connection with one another through one or more filter units 130 , 140 , 150 , 160 connected through a first and second flow-directing valve 170 , 180 . Each pump comprises a receiving chamber 112 , 122 and a moveable wall 114 , 124 connected through a drive shaft 116 , 126 to independent drives 118 , 128 . A solution 191 can be drawn into or expulsed from the receiving chamber 112 , 122 by the axial movement of the wall 114 , 124 relative to the body of the pump 110 , 120 (e.g. in the direction of the arrow shown in FIG. 2 ) when the drive 118 , 128 is activated. The walls of the receiving chamber 12 , 22 are made of an inert material, such as glass, ceramics, stainless steel or an appropriate plastic polymer which can withstand high operational pressures and not react with any components within the solution.
[0058] In use, solutions 191 , 192 , 193 , 194 (which each comprise a component of interest in mixture with other components) are sequentially aspirated from their respective sample containers into the receiving chamber 112 of the first pump 110 by movement of the wall 114 in the opposite direction to the arrow shown in the figure. The use of the system 2 will be described in relation to separating components of interest from a single solution 191 but it will be understood that the system can be used sequentially to separate components from other components within a plurality of solutions (e.g. from solutions 192 , 193 , 194 ). In the present example, the solution 191 contains a protein of interest which is to be separated from other components present in the solution and concentrated by ultrafiltration.
[0059] As described in FIG. 1 above, the first step in the process is for the solution 191 to be drawn from its sample container into the receiving chamber 112 of the first pump 110 via the flow directing valve 170 by means of tubing 171 . The tubing 171 and valve 170 are made of conventional materials, such as metals or plastics, which do not react with any components in the solution. The valve 170 , comprises one or more ports (not shown) which can be used to allow the valve 170 to act as a filter unit 130 selecting valve and/or an inlet/outlet valve.
[0060] In the first half of the cycle, solution 191 is driven from the receiving chamber 112 of the first pump 110 , by movement of the wall 114 in the direction of the arrow shown in FIG. 2 , through the valve 170 and into the filter unit 130 via tubing 176 . The first pump 110 thus controls or regulates the flowrate of ‘feed’ solution 191 (i.e. the solution prior to filtration) moving into and through the filter unit 130 .
[0061] The filter unit 130 comprises a first inlet 132 in fluid communication with a second inlet 134 , the inlets being connected to the first and second flow-directing valves 170 , 180 , respectively, by inert tubing 176 , 186 . The inlets 132 , 134 are separated from an outlet 231 by a membrane 138 which is selectively impermeable to the component of interest. An ultrafiltration membrane will be chosen which has pore sizes such that the component of interest within the solution (in this case a protein) will be retained by the membrane (i.e. the retentate) whereas smaller components will pass through it (i.e. the permeate). The membrane may be hollow or flat in configuration; in the example shown a hollow membrane is used such that permeate passing through the membrane may then be expulsed from the system through outlet 136 as waste.
[0062] As shown in FIG. 2 , the second pump 120 is in fluid communication with the first pump 110 by means of the first and second flow-directing valves 170 , 180 . The pumps 110 , 120 are independently driven such that the receiving chamber 112 of the first pump 110 empties at a faster rate than the receiving chamber 122 of the second pump 120 fills. The higher speed of the wall 114 in emptying the first chamber 112 compared to the speed of the wall 124 in filling the second chamber 122 creates a pressure difference across the membrane 138 . This pressure difference determines the rate of separation of components across the membrane and is controlled by the differential speed of the walls 114 , 124 of the first 112 and second 122 receiving chambers. This pressure difference is monitored by pressure sensors 201 , 203 . Other sensors ( 202 , 204 , 205 ) may be employed to monitor other physical parameters (e.g. temperature, conductivity, pH, oxygen concentration, ultraviolet light absorption) within the system.
[0063] In the embodiment shown in FIG. 2 , the retentate following filtration is collected in the receiving chamber 122 of the second pump 120 and the permeate passing through the membrane 138 is discarded from the outlet 136 as waste.
[0064] When the wall 114 reaches the end position of the stroke in emptying the solution 191 from the chamber 112 , the first half of the cycle is complete and the movement of both drives 118 , 128 is reversed. In this half of the cycle, the ‘feed control’ pump (initially the first pump 10 in the first half of the cycle) becomes the retentate control pump and the retentate control pump (the second pump 120 in the first half of the cycle) becomes the feed control pump. The direction of flow is thus reversed such that retentate is driven from the second receiving chamber 122 back into the filter unit 130 and across the membrane 138 to further remove contaminating components from the retentate. Once again, the slower speed of filling the retentate control pump (first pump 110 in this phase of the cycle) relative to the speed of emptying the feed control pump (i.e. second pump 120 ) creates a pressure differential across the membrane 138 . The resulting retentate is aspirated into the first receiving chamber 112 . Permeate containing low molecular weight components passing through the membrane 138 is discarded as waste from outlet 136 .
[0065] In this way, contaminating components are sequentially removed from the solution 191 and the component of interest (e.g. a protein) is concentrated in the retentate. The retentate can be collected as product 211 at the end of the cycle.
[0066] The cycle can be repeated, either using the same retentate, or by aspirating fresh solution 191 into the first chamber 112 (or second chamber 122 ) to maintain the volume of solution within the system by means of the flow-directing valve 170 , 180 at the start of each new stroke. By replenishing the system with fresh solution 191 in this way, the system is not limited to simply processing volumes equivalent to the volume of the receiving chamber 112 , 122 . At the end of a complete cycle, the retentate is collected as product 211 and low molecular weight contaminating components are effluxed from the system via outlet 136 .
[0067] It will be understood that if diafiltration is desired, the retentate can be diluted with dialysis buffer at the end of either or both halves of the cycle by the addition of the appropriate buffer solution 230 into either or both receiving chambers 112 , 122 to maintain a constant sample volume. The retentate can thus be washed with buffer 230 at a suitable pH and/or having an appropriate ionic strength, either once or repeatedly, to ensure removal of low molecular weight contaminants. The resulting retentate can be collected as product 211 and can be further diluted, if required, in the dialysis buffer ready for characterisation.
[0068] Following the final collection of retentate as product 211 , the membrane 138 can be cleaned with washing fluid/buffers 221 , 223 at the end of a complete cycle to remove any contaminants (such as solids, particles, etc) which adsorb to the membrane surface and block the pores. In this way, the operational lifetime of the membrane can be increased and its efficiency maintained.
[0069] All materials used in the construction of the system which come into contact with the solution, retentate and/or permeate are selected to avoid any chemical interaction and to minimise physical adsorption with the components within the solution. Typically, the walls of the receiving chamber and valves are made of glass, ceramics or stainless steel and the tubing of an inert plastic polymer.
[0070] It will be understood by the person skilled in the art that other samples 192 , 193 , 194 can be sequentially filtered in a similar manner either through the same filter unit 130 or different filter units 140 , 150 , 160 which either contain the same or different membranes (e.g. microfiltration membranes having different pore sizes). Following filtration in the filter units 140 , 150 , 160 , retentate can be collected from the outlets (see shorter arrows) as product 212 , 213 and 214 .
[0071] The skilled person will also understand that other forms of separation membranes can be used in the system and method of the invention, either alone or in combination. Thus, for example, the system can be used to separate components on interest on the basis of size, charge, chirality by selection of the appropriate membrane. A combination of different types of membranes (e.g. ultrafiltration, microfiltration, affinity membranes, reverse phase membranes, ion exchange membranes, hydrophobic membranes) can be employed in the system, as illustrated in the embodiment depicted in FIG. 3 . The transverse section in FIG. 3 shows a system according to the invention utilising three different forms of separation—i.e. affinity chromatography, ultrafiltration and microfiltration. Such a system is particularly suitable for the separation of proteins from biological samples.
[0072] The system 3 has a similar configuration to that described in FIGS. 1 and 2 above and operates in a similar manner. A first pump 310 and second pump 320 are in fluid connection with one another through one or more filter units 330 , 340 , 350 connected through a first and second flow-directing valve 370 , 380 . Filter unit 330 contains an affinity membrane (not shown), unit 340 a microfiltration membrane 348 and unit 350 an ultrafiltration membrane 358 .
[0073] Each pump comprises a receiving chamber 312 , 322 and a moveable wall 314 , 324 connected through a drive shaft 316 , 326 to independent drives 318 , 328 . A solution 391 can be drawn into or expulsed from the receiving chamber 312 , 322 by the axial movement of the wall 314 , 324 relative to the body of the pump 310 , 320 when the drive 318 , 328 is activated. The walls of the receiving chamber 312 , 322 are made of an inert material, such as glass, ceramics, stainless steel or an appropriate plastic polymer which can withstand high operational pressures and not react with any components within the solution.
[0074] In the example shown, the solution 391 contains a protein of interest which is to be separated from other components present in the solution by affinity chromatography and microfiltration, followed by washing and diafiltration.
[0075] Solution 391 , which comprises a protein of interest in mixture with other components, is aspirated from its container into the receiving chamber 312 of the first pump 310 via tubing 371 and valve 370 by the upward movement of the wall 314 (i.e. in the opposite direction to the arrow shown in FIG. 3 ). The tubing 371 and valve 370 are made of conventional materials, such as metals or plastics, which do not react with any components in the solution. The valve 370 , comprises one or more ports (not shown) which can be used to allow the valve 370 to act as a filter unit 330 selecting valve and/or an inlet/outlet valve.
[0076] In the first half of the affinity separation cycle, solution 391 is driven from the receiving chamber 312 of the first pump 310 , by movement of the wall 314 in the direction of the arrow shown in FIG. 3 , through the valve 370 and into the filter unit 330 (via tubing 376 ). As described in FIGS. 1 and 2 above, the first pump 310 controls or regulates the flowrate of ‘feed’ solution 391 (i.e. the solution prior to filtration) moving into and through the filter unit 330 .
[0077] The filter unit 330 comprises a first inlet 332 in fluid communication with an outlet 334 , the inlet and outlet being connected to the first and second flow-directing valves 370 , 380 , respectively, by inert tubing 376 , 386 . The inlet 332 is separated from the outlet 334 by an affinity membrane (not shown) to which the protein of interest in the solution selectively binds. Affinity membranes are well known in the art (see for example ‘Affinity Membranes: Their Chemistry and Performance in Adsorptive Separation Processes’, E Klein, 1991) and are commercially available from a number of suppliers (e.g. GE Healthcare Life Sciences). An affinity membrane will be chosen or prepared such that the protein of interest is bound to the membrane while other components in the sample pass through the membrane and are collected in the receiving chamber 322 . The contents of the receiving chamber 322 are then discarded as waste 336 in the second half of the cycle following reversal of the flow (as described in FIGS. 1 and 2 above).
[0078] Bound protein is released from the affinity membrane in the second cycle by washing with an appropriate affinity buffer 431 and collecting the protein-enriched fraction in the receiving chamber 322 (the process may be repeated using an additional affinity buffer 432 as required to ensure complete removal of the protein from the affinity membrane). This fraction may be purified by passage across microfiltration membrane 348 in the second half of the cycle, to remove any high molecular weight contaminants, the resulting permeate 345 being collected.
[0079] The permeate 345 can then be concentrated further or subjected to diafiltration by passage across ultrafiltration membrane 358 in a third cycle. If diafiltration is desired, the permeate 345 is diluted with a dialysis buffer 430 and the retentate obtained by passage across the membrane in the first half of the cycle is collected as product 411 , either directly or following further dilution with dialysis buffer 430 , the permeate being discarded as waste 355 . Alternatively, the retentate may be purified still further by reversing the direction of flow across the ultrafiltration membrane 358 (as described in FIGS. 1 and 2 above) to remove any remaining low molecular weight components and collecting the retentate in the first receiving chamber 312 (the permeate from the ultrafiltration being discarded as waste 355 ). The retenate can then be collected directly as product 411 by expulsion from chamber 312 (via valves 370 / 380 ) or diluted further with diafiltration buffer 430 prior to collection as product 411 (via valves 370 / 380 ).
[0080] If the user simply wishes to concentrate the protein, then the permeate 345 is subjected to the ultrafiltration steps described above without the addition of the diafiltration buffer 430 . The retentate produced is then collected as product 411 .
[0081] Washing fluids 421 , 422 , 423 can be used to clean the membranes and filter units 330 , 340 , 350 at the end of a complete cycle.
[0082] It will be understood that the skilled person may wish to carry out variations in the separation process described in FIG. 3 above. Thus, for example, it is possible to carry out the same process but in a different sequence (e.g. microfiltration first, followed by ultrafiltration/diafiltration and then affinity separation). Such variations are clearly possible, the order in which each of the separation steps are conducted depending upon the objective of the skilled person.
[0083] The above embodiments are to be understood as illustrative examples of the invention. Further embodiments of the invention are envisaged. It is to be understood that any feature described in relation to any one embodiment may be used alone, or in combination with other features described, and may also be used in combination with one or more features of any other of the embodiments, or any combination of any other of the embodiments. Furthermore, equivalents and modifications not described above may also be employed without departing from the scope of the invention, which is defined in the accompanying claims.
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The invention provides an automated crossflow filtration method and system for separating a component of interest from one or more other components in a solution. The invention is of particular use in the field of protein separations and concentration, where specific proteins must be separated and purified from cell lysates and cultures. The system may be under the control of a computer software programme.
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The present Application for Patent is a divisional of patent application Ser. No. 10/032,957 entitled “METHOD AND APPARATUS FOR PARTITIONING MEMORY IN A TELECOMMUNICATION DEVICE” filed Oct. 26, 2001, now U.S. Pat. No. 7,502,817, and assigned to the assignee hereof and hereby expressly incorporated by reference herein.
FIELD OF THE INVENTION
The present invention is related generally to telecommunication and, more specifically, to a technique for partitioning memory to conserve power in telecommunication devices.
BACKGROUND OF THE INVENTION
Wireless telecommunication devices are evolving to contain increased functionality and complexity. This increased functionality often brings together functions that have been traditionally been provided by different devices such as cell phones and personal digital assistants (PDA). The combination of these functions typically require increased processor capability as well as increased power requirements. The requirement for additional processing capability to add functionality and minimize latency is especially important when the information must be processed in real time, as for example in cell phones. Having more processing capability and in turn higher power consumption, is especially problematic in wireless communication systems where it is inconvenient to connect to power sources.
Wireless communication systems generally must contain their own source of power, which often is in the form of a battery. Users typically need the ability to operate such systems for longer periods of time without the need to recharge or swap batteries or even connect to line power. However, such longer operating times normally require an increase in battery size, which leads to undesirable effects such as heavier batteries, increased expense, and environmental concerns regarding disposal of used batteries.
To meet the needs of increased processing power within wireless communication devices, additional processors requiring more memory and power were added to devices. A general purpose processor handles most system tasks and a modem computing subsystem handles tasks related to handling mobile station requirements. Mobile station modem binary software images (i.e., contents of memory) are programmed at the time of manufacture into read-only memory (ROM) as a single contiguous binary image. The modem computing subsystem directly executes the memory image from ROM, which results in slower execution than images executed from memories with faster access times, such as random access memory (RAM). At system boot time (e.g., when the wireless device is powered-up), read-write and zero-initialized data are copied to RAM prior to execution of code by the modem computing subsystem. No part of the over-the-air standards as implemented in the software binary image can be executed prior to completion of system boot and initiation of the operating system. All system memory must be completely powered-up prior to mobile station modem operation of the over-the-air standard. This approach results in wasting significant amounts of power because the modem computer subsystem had to be powered up even when not in use.
Therefore, it can be appreciated that there is a significant need for a system and method to minimize power consumption in a wireless communication system while increasing the speed and functionality of the device for the user. The present invention provides this and other advantages that will be apparent from the following detailed description and accompanying figures.
SUMMARY OF THE INVENTION
The present invention is embodied in a method and apparatus for partitioning and downloading executable memory images in low-powered computing devices comprised of multiple processors and a mobile station modem. In one embodiment, the system comprises a communications-related personal digital assistant (PDA) that contains two computer subsystems. The general computing subsystem handles tasks generally related to a PDA as well as gating independently the clock that activates the modem computer subsystem and one or more shared memory modules. The modem computing subsystem handles tasks associated with a mobile station modem. The system is able to conserve power by not clocking the modem computer system and the shared memory during times when the modem function is not needed. The shared memory modules are loaded with a binary memory image for use by the modem computer subsystem from a nonvolatile memory by the general computing subsystem.
In another embodiment, the system boots the general computing subsystem, which contains a nonvolatile memory, boots the modem computing subsystem when it is desired to monitor a paging channel, and disables the modem computing system to conserve power when it is no longer desired to monitor the paging channel. This embodiment may enable the modem computing system by providing a clock to the first shared memory module, loading the shared memory module with a binary memory image based on information stored in the nonvolatile memory, providing a clock to activate the modem computing subsystem, and vectoring the processor so that it executes instructions from the binary memory image stored on the shared memory module. The modem computing subsystem may be deactivated to save power when the modem function is not necessary. Additionally, a second shared memory may be activated and used only when the modem computing system needs to manage a traffic channel.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top-level block diagram of the present invention.
FIG. 2 is a functional block diagram of exemplary interfaces of the present invention.
FIG. 3 is a detailed functional block diagram of the system.
FIG. 4 is a flow chart illustrating an example of the processing steps of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention permits the independent activation and deactivation of portions of a low-powered telecommunication and computing device that are only required in the course of transmitting and receiving data. In an exemplary embodiment, the present invention is implemented using a wireless modem station operating in conjunction with a personal digital assistant (PDA). The combination device may be referred to as a mobile unit, cellular telephone, communicator, or the like. As will be discussed in greater detail below, the present invention is not limited to a specific form of mobile communication device, nor is it limited to a particular over-the-air standard.
The present invention is embodied in a system 100 , which is illustrated in the block diagram of FIG. 1 . The system 100 includes a general computing subsystem 102 and a modem computing subsystem 104 , which will be described in greater detail below.
The general computing subsystem 102 provides control lines 106 that are used to activate, synchronize, and deactivate the modem computing subsystem 104 . Both the general computing subsystem 102 and the modem computing subsystem 104 may alternately assert or remove a clock signal to a shared memory modules Bank I 108 and Bank II 110 in the course of activating modem functions. The shared memory modules 108 - 110 are loaded by the general computing subsystem 102 and contain an executable binary memory image for use by the modem computing subsystem 104 . The executable binary memory image comprises instructions and data that the processor of the modem computing subsystem 104 will execute and manipulate. A bus 112 is used to load and access the shared memory module 108 , and a bus 114 is used to load and access the shared memory module 110 . The general computing subsystem 102 generates clock signals BNK I CLK 116 and BNK II CLK 118 , respectively to control the operation of the memory modules 108 - 110 , respectively. Similarly, the modem computing subsystem 104 generates clock signals BNK I CLK 120 and BNK II CLK 122 to control operation of the memory modules 108 - 110 , respectively. The operation of the clock signals 116 - 122 to control the memory modules 108 - 110 is discussed in greater detail below.
FIG. 2 is a functional block diagram of exemplary interfaces of the present invention. It will be apparent to one skilled in the art that each of the interfaces of system 100 may be directed to the general computing subsystem 102 and the modem computing subsystem 104 either operating together or alone depending on how the functionality of each the interface is used and when the functionality is needed. In one embodiment interfaces that are needed to operate the PDA in general are classified as a PDA peripherals 220 and interfaces that are only needed during operation of the modem computing subsystem 104 are classified as modem peripherals 244 .
The system 100 , which typically embodies the functions of both a computing device, such as a PDA and a wireless communicator, includes a transceiver and antenna 128 to allow transmission and reception of data, such as audio communications, between the system 100 and a remote location, such as a cell site controller (not shown). The remote location may host data and communications services such as voice, data, email and internet connections. The operation of the wireless voice and data communications is well known in the art and need not be described herein except as it relates specifically to the present invention.
Preferably, system 100 comprises a power management device 130 that comprises a rechargeable battery and that provides a power supply. System 100 operates in different operational modes with each operational mode having a different level of power consumption, including “Fully Active” wherein the PDA is active and a voice call is in progress, “PDA Active” wherein the PDA is active and the modem and modem functions are asleep, “Phone Active” wherein the PDA is asleep and a voice call is in progress, “Sleep” wherein the PDA is asleep, no voice call, and slotted paging mode is active, and “Deep Sleep” wherein the PDA is asleep and the phone is off. Those skilled in the art will appreciate that a “voice” call can comprehend the functionality of an active traffic channel (including data traffic), and that in the slotted paging mode the modem processor periodically listens to transmissions from a base station to determine if there is an incoming call. It can be readily seen that other combinations of functionality and power consumption are possible. The power management device 130 also may include a sleep timer to awaken the system 100 after a predefined time interval.
The system comprises human interfaces for providing information to and receiving information from users. Visual indicators such as a serial liquid crystal display (LCD) 132 , a color liquid crystal display 134 , and light-emitting diodes (not shown) are used to rapidly convey information to the user. Tactile receptors such as a touch screen 130 and keypad 138 allow the user to enter data and commands and to manually respond to system queries. It is apparent to those skilled in the art that other display types and input devices may be used acceptably. Audio input and output, provided by headset/mic 140 and stereo digital-to-analog converter (DAC) 142 , allow for two-way communication, as well as command input by using voice recognition, and aural responses to user input. Ideally, the human interfaces and physical system design will be presented in a pleasing and ergonomic fashion so as to provide for ease-of-use of the device.
Interfaces are provided to allow for expandability, such as a multimedia card (MMC) slot 144 , and one or more memory expansion slots 146 . Communication between the system 100 and other computers or devices can be accomplished via a serial port 150 , which is preferably a universal serial bus (USB) transceiver. JTAG-type (Joint Test Action Group) boundary scan testing may also be provided.
FIG. 3 is a detailed functional block diagram according to the invention. The general computing subsystem 102 and the modem computing subsystem 104 are controlled by a general system microprocessor 202 and a modem subsystem processor 204 , respectively. Those skilled in the art will appreciate that the term “processor” is intended to encompass any processing device, alone or in combination with other devices, that is capable of operating the telecommunication system. This includes microprocessors, embedded controllers, application specific integrated circuits (ASICs), digital signal processors (DSPs), state machines, dedicated discrete hardware, and the like. The present invention is not limited by the specific hardware component selected to implement the processors 202 and 204 .
The general computing subsystem 102 comprises a power management unit (PMU) 205 that receives as an input an external reset signal. This signal may be derived from a power-up circuit, an external reset button, or a sleep timer. The PMU 205 provides a clock to the general subsystem processor 102 as well as bank arbitration blocks 206 and 208 of the shared memory modules 108 and 110 , respectively. The PMU 205 may be programmed by and provide status data to the general computing subsystem processor 202 via a general computing subsystem bus 209 .
Subsystem bus 209 may include a power bus, a control signal bus, and a status signal bus in addition to a data bus. However, for the sake of clarity the various buses are illustrated in FIG. 3 as the subsystem bus 209 . The subsystem bus 209 allows the general computing subsystem processor 202 to receive and send data to nonvolatile memory 222 and static RAM (SRAM) 224 , to control registers 216 , to the shared memory modules Bank I 108 and Bank II 110 , and to PDA peripherals 220 . A busmaster 211 provides additional logic for bus interface control logic as well as electrical buffering of signals on subsystem bus 209 .
To conserve power and offload processing requirements of the general computing subsystem processor 202 , a DMA (direct memory access) channel is provided to transfer data without processor intervention. DMA technology is well known in the art and need not be discussed here. A DMA/microprocessor memory interface 210 , DRAM controller 212 , and MMC DMA Controller 214 are provided to allow direct memory access of the shared memory modules 108 and 110 by the general subsystem processor 202 and the PDA peripherals 220 via the memory interface bridge 218 . The MMC DMA Controller 214 may be configured as the DMA master and the DRAM controller 212 and MMC DMA Controller 214 are configured as slaves.
The DMA/microprocessor memory interface 210 also serves to allow proper access to the nonvolatile memory 222 and SRAM 224 by the general computing subsystem processor 102 . In typical embodiments nonvolatile memory 222 is a memory such as flash ram that is preprogrammed with boot code, operating instructions, and data for both the general computing subsystem processor 202 and the modem computing subsystem processor 204 . A portion of the memory contents of nonvolatile memory 222 may optionally be stored and accessed according to well known data compression techniques for the purpose of reducing the amount of nonvolatile memory required. The data and instructions required for the operation of the modem computing subsystem processor 204 are copied from nonvolatile memory 222 and stored in SRAM 224 , which has lower access times than that of a nonvolatile memory thus permitting faster execution by the modem computing subsystem processor 204 .
The modem computing subsystem 104 comprises a clock/power control unit 230 that provides clocks 120 - 122 to the bank arbitration blocks 206 and 208 of the shared memory modules 108 - 110 , respectively, and provides a clock 250 and a reset line 252 to the modem subsystem processor 204 . The clock/power control unit 230 is used to conserve power by gating (i.e., shutting off) the clock 250 to the modem subsystem processor 204 and the clocks 116 - 122 to the shared memory modules 108 - 110 , respectively, during times when these modules are not needed for operation of the modem portion of the system 100 .
When the modem system processor 204 is needed in one embodiment, clock 250 will be applied to the modem subsystem processor 204 , and clock 116 from the general computing subsystem 102 is applied so that the Bank I shared memory module 110 may be loaded by the general computing subsystem 102 . The clock 116 is maintained so as to allow the data stored in the module 110 to be refreshed. The modem computing subsystem 104 may access the module 110 by asserting clock 120 . The modem computing subsystem 104 may access the Bank II shared memory module 112 by asserting clock 122 , which maybe used to keep the data stored in module 112 refreshed after the data is stored therein by the general modem computing subsystem 102 . The general modem computing subsystem 102 may access the module 112 by asserting clock 118 .
The general computing subsystem 102 uses the control registers 216 to signal a clock/power control unit 230 to supply the clocks 120 - 122 to the shared memory module 108 so that the boot code for modem computing subsystem 104 may be stored and retained in the shared memory module 108 . The control registers 216 also are used to reset and start the modem computing subsystem processor 204 , which will then access the boot code in the shared memory module 108 .
In one embodiment, the modem subsystem processor 204 communicates with the general computing subsystem processor 202 via shared memory modules 108 - 110 by using locations in memory to store information about the status and mode of operation of the modem computing subsystem 104 . The general computing subsystem processor 102 polls the status information and signals the clock/power control unit 230 to assert and remove the clocks 120 - 122 , as well as to load portions of the shared memory modules 108 - 110 . Alternatively, the modem subsystem processor 204 may signal the general computing subsystem processor 202 using, by way of example, a vectored interrupt method to instruct the general computing subsystem processor 202 to, for example, load a portion of the shared memory modules 108 - 110 .
A subsystem bus 240 allows the modem computing subsystem processor 204 to receive and send data to control registers 242 , to the shared memory modules 108 - 110 , and to modem peripherals 244 . The subsystem bus 240 may include a power bus, a control signal bus, and a status signal bus in addition to a data bus. However, for the sake of clarity the various buses as the subsystem bus 240 . A busmaster 246 provides additional logic for bus interface control logic as well as electrical buffering of signals on subsystem bus 240 .
To conserve power and offload processing requirements of the modem computing subsystem processor 204 , a DMA channel is provided to transfer data without processor intervention. A DMA Controller/microprocessor memory interface 260 is provided to allow direct memory access of the shared memory modules 108 - 110 by the modem subsystem processor 204 and the modem peripherals 244 via a memory interface bridge 262 .
The modem computing subsystem 104 uses the control registers 242 to signal the clock/power control unit 230 to supply clock pulses via clock 120 to the shared memory module 110 so that the modem operational software image for modem computing subsystem 104 may be stored and retained in the shared memory module 110 . This will typically occur prior to the modem computing subsystem 104 leaving the slotted paging mode and entering the traffic mode. The control registers 216 also are used to signal the clock/power control unit 230 via signal 226 to remove the clock 122 from the shared memory module 110 when the modem computing subsystem 300 reverts to the slotted paging mode from the traffic mode.
The shared memory modules 108 - 110 each comprise one or more dynamic RAMS 280 and 282 , respectively, so that power is conserved when the memory is not clocked. As an additional benefit, the cost of the DRAM is less than that required for static RAM. The shared module 108 is used for storing the boot code of the modem subsystem processor 204 and the software necessary for operating the modem computing subsystem 104 when the wireless device is operating in the slotted paging mode. The shared memory module 110 is used for storing the software necessary for operating the modem computing subsystem 104 when the wireless device is operating in the traffic mode. It will be apparent to those skilled in the art that other shared memory modules may be used to further partition the memory image so that the additional memory banks need only be activated during certain modes that would be associated with the code stored in the additional banks.
The bank arbitration blocks 206 and 208 each receive clocks (i.e., the clocks 116 - 122 ) from the general computing subsystem 102 and the modem computing subsystem 104 because the subsystem processors (i.e., the general subsystem processor 202 and the modem subsystem processor 204 ) are not necessarily synchronized, the bank arbitration blocks 206 - 208 must be capable of handling the protocols of memory requests from systems having unrelated clocks. The arbitration blocks 206 and 208 each must not only handle unrelated clocks, but also be capable of handling simultaneous and nearly simultaneous requests from both subsystems. The arbitration blocks 206 and 208 receive the requests via the memory interface bridges 218 and 262 , resolve any contention between the subsystems, synchronize the local clocks to the subsystem having priority, and respond via the appropriate memory interface bridge to the subsystem having priority. Such arbitration techniques are well known in the art and need not be described in greater detail herein.
FIG. 4 is a flowchart illustrating the operation of a low-powered telecommunication and computing device according to the present invention. These steps are performed by the device as it is powered up and enters various modes.
Specifically, in step 300 , a general computing subsystem reset occurs either upon applying power to the system 100 , or at anytime when requested. The general computing subsystem reset may be applied during any step described herein, although this capability has been omitted from the flowchart of FIG. 4 for the sake of clarity. After reset, the general computing subsystem 102 boots in step 302 . To conserve power, in step 304 all unnecessary clocks are disabled, including the clocks (e.g., the clocks 120 - 122 and the clock 250 ) in the modem computing subsystem 104 . The modem computing subsystem 104 is placed in a reset mode in step 306 .
In step 308 , the general computing subsystem 102 applies a clock (i.e., the clock 118 ) to shared memory module 110 . A software memory image necessary for the operation of the modem computing subsystem 104 to boot and enter and maintain the slotted paging mode is loaded into the shared memory module 108 in step 310 . The modem computing subsystem 104 is released from reset in step 312 , and then boots in step 314 using instructions and data from the memory image stored in the shared memory module 108 . The modem computing subsystem 104 enters the slotted paging mode in step 316 and monitors the paging channel until, in decision 318 , a request for traffic is detected (for incoming requests) or posted (for outgoing requests).
Upon such a request, in step 320 , the general computing subsystem 102 applies the clock 116 to the shared memory module 110 . A software memory image necessary for the modem computing subsystem 104 to operate a traffic channel for voice, data, or SMS is loaded into the shared memory module 110 in step 322 . When the memory image is loaded, in step 324 the modem subsystem processor 204 accesses the contents of the shared memory module 110 for code and data necessary to facilitate a traffic channel. In decision 326 , the modem subsystem processor 204 determines whether traffic is present and, if so continues in step 324 , else continues on to step 328 , where the clocks to the shared memory module 110 are removed and the modem computing subsystem 104 then returns to step 316 where the slotted paging mode is again reentered. Thus, the system 100 provides increased computing and data processing capability while controlling circuitry to reduce power consumption.
It is to be understood that even though various embodiments and advantages of the present invention have been set forth in the foregoing description, the above disclosure is illustrative only, and changes may be made in detail, yet remain within the broad principles of the invention. Therefore, the present invention is to be limited only by the appended claims.
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An apparatus and method are disclosed for partitioning and downloading executable memory images in low-powered computing devices comprised of multiple processors and a mobile station modem. The general computing subsystem 102 handles tasks generally related to a personal digital assistant (PDA) as well as activating the modem computer subsystem 104 and one or more shared memory modules 108 - 110 . The modem computing subsystem 104 handles tasks associated with a mobile station modem. Power is conserved by not clocking the modem computer system 104 and the shared memory 108 - 110 during times when modem functions are not needed. The shared memory modules 108 - 110 are loaded with a binary memory image for use by the modem computer subsystem 104 from a memory 222 under control of the general computing subsystem 102 . When needed, the modem computing subsystem 104 is activated to monitor a paging channel, and disabled when it is no longer desired to monitor the paging channel. Additionally, a second shared memory 110 may be activated and used only when the modem computing system 104 needs to manage a traffic channel.
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FIELD OF THE INVENTION
This invention relates to a tractor-driven nut shaker that extends perpendicular to a boom attached to the tractor. A shaking head of the nut shaker is slidably mounted on a carriage so as to grab a tree with its jaws and shake nuts from the tree.
BACKGROUND OF THE INVENTION
Currently, the nut industry uses a machine called a "monoboom" shaker for shaking of nuts from trees. An exemplary monoboom shaker is shown in FIG. 1 and is generally illustrated at 20.
The nut shaker 20 includes a tractor 21, a boom section 22 extending in a direction of travel of the tractor. Two head support arms 24 are mounted on a hollow sleeve 23. The hollow sleeve 23 is rotatably mounted on a rod 25. Rod 25 is fixed to the boom section 22 and extends perpendicular to boom section 22.
A shaker head 26 is connected to head support arms 24 by rubber mounts (not shown). The shaker head 26 includes jaws 32 which are movable towards and away from each other.
The ends 26 of the arms 24 are mounted to the piston and cylinder support section 28 by piston and cylinder assemblies, schematically shown by lines 30. The support section 28 is fixed to the boom section 22.
By actuation of the piston cylinder assembly schematically represented at 30, the shaker head 26 is allowed to tilt and roll with respect to boom section 22 by rotation of sleeve 23 about rod 25. The shaker head extends in a direction of travel of the tractor and in the direction of the longitudinal axis of the boom section 22.
For the shaking of trees, the nut shaker 20 as shown in FIG. 2 is driven between rows of trees 34 and rows of trees 36. Initially, the tractor 21 is driven in a line extending parallel to the rows of trees 34, 36. The tractor is then turned towards a tree as shown in FIG. 2 and the jaws 32 opened and then closed about a tree so as to shake the tree and force the fall of nuts from the tree.
The operator then opens the jaws of the shaking head and reverses the direction of the tractor 21. The operator then straightens out the direction of travel of the nut shaker so as to again proceed parallel to the direction of rows of trees 34 and 36 until turning into another tree and grasping the tree to repeat the procedure for producing the fall of nuts.
Under certain conditions, the maneuvering of the nut shaker 20 shown in FIGS. 1 and 2 is unacceptable to the grower. For instance, when the tree rows are close together and each of the trees of each row are planted close together in their respective row, it becomes difficult to maneuver the tractor with its forward extending boom section and shaker head.
It then becomes necessary to undergo the enormous expense of building a specialized machine 40 as shown in FIG. 3 having an overall length 42 which is substantially less than its width 44. Extending from the tractor is a shaker head 46 which moves in and out in the direction of arrow 48 so as to engage and shake a tree by clamping jaws 50. To contact an adjacent tree, the tractor 40 is driven in the direction of arrow 52 with the operator of the tractor facing perpendicular to the line of travel 52 as represented by the arrow 54.
SUMMARY OF THE INVENTION
By the present invention, difficulties encountered by prior known nut shaking machines and specially manufactured machines have been overcome by the use of a modification to existing monoboom shakers. Existing monoboom shakers are modified by removal of the shaker head and substitution of a shaker head on a carriage so that the shaking head extends perpendicular to the machine direction of travel and perpendicular to the boom section connected to the tractor.
The shaking head is slid in and out on a carriage which extends perpendicular to the boom section. The carriage is mounted on a hollow sleeve which can fit on the rod projecting perpendicularly from the boom section of an existing monoboom shaker. The same tractor and boom can thereby be used from a traditional monoboom shaker and modified by the present invention at a minimum cost so that the shaker head extends perpendicular to the boom section to accommodate various needs of nut farmers.
By the present invention, a shaking head is slidably mounted on a carriage which extends perpendicular to a boom connected to a tractor. The shaking head is reciprocally mounted on the carriage so as to move towards and away from trees located along the side of the tractor. The carriage is secured to a hollow sleeve which is rotatably and removably mounted on a rod projecting from the boom section.
By advancement of the tractor in a direction parallel to a row of trees, the trees are accessible by the shaking head of the nut shaker. This prevents the need for extensive maneuvering of the tractor to obtain access to a nut tree or to build an expensive, specialized tractor so as to gain access to trees when the separation between rows of trees is limited.
It is therefore an object of the present invention to replace a shaking head of a monoboom shaker with a shaking head slidable on a carriage extending perpendicular to a boom section of the monoboom shaker.
It is another object of the present invention to replace a shaking head of a monoboom shaker with a shaking head slidable on a carriage extending perpendicular to a boom section with the boom section extending in the same direction as the direction of travel of the tractor to which it is mounted.
It is still yet another object of the present invention to replace a shaking head of a monoboom shaker with a shaking head slidable on a carriage extending perpendicular to a boom section with the boom section extending in the same direction as the direction of travel of the tractor to which it is mounted so as to operate a tractor in a restricted width area between rows of nut trees.
These and other objects of the invention, as well as many of the intended advantages thereof, will become more readily apparent when reference is made to the following description taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view of a known monoboom shaker.
FIG. 2 schematically illustrates the monoboom shaker of FIG. 1 engaging a nut tree.
FIG. 3 is a schematic representation of a specialized nut shaker built to move between narrow rows of nut trees.
FIG. 4 illustrates a nut shaker of the present invention having a shaking head extending perpendicular to the direction of travel of the tractor and perpendicular to a boom section onto which it is mounted.
FIG. 5 illustrates a boom section, carriage and shaking head.
FIG. 6 is a plan view of the boom section, carriage and shaker head.
FIG. 7 is a side view of a shaker head mounted on a carriage with an end of the boom section shown.
FIG. 8 is an end view of a shaking head slidably mounted on a carriage which extends from a boom section.
FIG. 9 schematically illustrates the use of the present invention between a row of nut trees for shaking of the trees.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In describing a preferred embodiment of the invention illustrated in the drawings, specific terminology will be resorted to for the sake of clarity. However, the invention is not intended to be limited to the specific terms so selected, and it is to be understood that each specific term includes all technical equivalents which operate in a similar manner to accomplish a similar purpose.
With reference to the drawings, in general and to FIGS. 4 through 9 in particular, a nut shaker embodying the teachings of the subject invention is generally designated as 60. With reference to its orientation in FIG. 1, the nut shaker 60 includes a tractor 62 having a boom section 64 mounted thereon, extending in a direction of travel of the tractor 62. The tractor and boom section are part of a traditional monoboom shaker.
Extending perpendicular to the boom section 64 is a rod 102. Rotatably mounted on the rod 102 is a sleeve 100 to which is secured a carriage 66 by bracket 98. At the end of the carriage is mounted a shaking head 68.
The shaking head includes two jaws 70 which are movable towards and away from each other for grasping of a nut tree. The shaking head is mounted on a slidable member 72. Secured to the slidable member 72 is a bracket 74 and a bracket 76. Secured to the shaking head 68 is a bracket 78 shaped the same as bracket 74. Between brackets 74 and 78 are two C-shaped brackets 80 having holes 82 at opposite ends for securing rubber mounts 84 between the brackets 74 and 80 and between the brackets 80 and 78.
In FIG. 4, the right-hand interconnection of rubber mounts and brackets is shown and the left-hand connection is omitted to illustrate the alignment of the various holes of the brackets interconnected by the rubber mounts 84. The rubber mounts 84 at all connector points are shown in FIGS. 6 through 8.
Towards the rear 86 of the shaking head, a bracket 108, similar to bracket 78, is shown in FIG. 7 so as to illustrate the interconnection with the C-shaped clip 88. The bracket 108 secures the rear of the shaking head to the slidable member 72 through bracket 76 and clip 88.
The sliding member 72 includes a square-shaped opening 90 for receipt of the square shaped carriage 66. A piston and cylinder assembly 92 engages the sliding member 72 at connector 94, shown in FIGS. 7 and 8, with its opposite end 96 of the cylinder connected to bracket 98 fixed in position to rotatable cylinder 100 which rotates about interior rod 102. By extension of the piston of the piston cylinder assembly 92, the sliding member 72 is slid along the carriage 66 for extension and retraction of the shaking head towards a tree.
The lateral angle of the shaking head is adjusted by extension and retraction of piston cylinder assembly 104 which is anchored at one end to anchor plate 106, as represented by section 28 in FIG. 1, and at its opposite end to the carriage 66. The entire carriage and shaking head assembly may be rotated about interior rod 102 about which exterior sleeve 100 rotates with the carriage.
As shown in FIG. 9, the nut shaker 60 proceeds in the direction of travel parallel to the rows of nut trees 120 and 122 as shown by arrow 112. The operator sitting in the tractor 62 faces in the direction of arrow 114 which is also parallel to arrow 112.
The boom section 64 extends in the direction of travel of the tractor. The carriage 66 and the shaking head 68 extend perpendicular to the boom section 64 and the direction of travel 112 of the tractor 62. The shaking head 68 is slidably mounted on the carriage 66 for reciprocal movement in the direction of arrow 116 for engagement with a tree 118 of the row of trees 120. The tractor may thereby be moved down the middle between rows of trees 120 and 122 with no deviation from a straight line of travel to access and shake each of the successive trees in the row 120. The tractor is then turned around and moved between the rows of trees 122, in the opposite direction of travel from engaging row of trees 120, to access each successive tree in row 122 by again travelling in a straight line.
Having described the invention, many modifications thereto will become apparent to those skilled in the art to which it pertains without deviation from the spirit of the invention as defined by the scope of the appended claims.
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A shaking head is slidably mounted on a carriage which extends perpendicular to a boom connected to a tractor. The shaking head is reciprocally mounted on the carriage so as to move towards and away from trees located along the side of the tractor. The carriage is secured to a hollow sleeve which is rotatably and removably mounted on a rod projecting from the boom section.
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CROSS REFERENCE TO RELATED APPLICATIONS
The present application claims priority of French Application No. 02 12586 filed Oct. 10, 2002 and claims the benefit of U.S. Provisional Application No. 60/447,008 filed Feb. 13, 2003, the teachings of which are incorporated herein by reference.
FIELD OF THE INVENTION
The present invention relates to an applicator for applying a substance, for example, nail varnish, to nails.
BACKGROUND OF THE INVENTION
A nail varnish applicator is known from European patent EP 0 651 955, comprising a rod, and bristles fixed in a housing of the rod, the housing being of oblong cross-section. In the examples shown in that patent, the opening of the housing has in cross-section a contour that matches the contour of the rod in the shape of a kidney or with two main sides slightly concave outwardly, such that the thickness of the wall surrounding the housing is constant.
A nail varnish applicator is also known from JP-4-28812, having a rod that includes a plurality of longitudinal grooves distributed in substantially uniform manner over its entire periphery.
SUMMARY OF THE INVENTION
A need exists to facilitate applying a substance such as nail varnish and to enable it to be spread more precisely. The Applicant has observed that with known applicators, the substance which flows along the rod and reaches the sides of the brush is relatively difficult to spread with precision.
According to one or more embodiments of the present invention, an applicator comprises a rod and bristles fixed in a housing of an end portion of the rod, the housing having an opening of oblong cross-section with a long axis X, and the rod having a wall of varying thickness around the housing.
In one aspect of the invention, in the end portion of the applicator including the housing that receives the bristles of the brush, the rod has a cross-section having an outer contour that is not concave, with the exception of one or more grooves situated opposite each other. The groove(s) extend along at least a portion of the rod and are situated substantially mid-way along the long axis X of the housing when the rod is observed in cross-section. According to certain embodiments, the outer contour of the rod may be convex and, where appropriate, it may include at least one flat side.
In one or more embodiments of the invention, the thickness or depth around the rod of the substance for application is greater in the groove(s) than on the sides. According to these embodiments, the substance which flows along the rod when the applicator is removed from the receptacle thus reaches the bundle of bristles preferentially in a substantially central region of said bundle, so that the substance can be spread under good conditions. The quantity of substance reaching the sides of the brush is small.
As mentioned above, the rod may include a second groove, opposite the first, and the applicator may be symmetrical about a mid plane. The two grooves can thus be symmetrical about a mid-plane parallel to the long axis X, but it is within the scope of the present invention for the grooves to be of different shapes.
In certain embodiments, the opening of the housing may advantageously have a cross-section that is substantially rectangular, thereby enabling a substantially uniform distribution of substance on the bristles to be obtained, but other shapes are within the scope of the present invention, for example, an oval cross-section.
According to one or more embodiments, in cross-section, the end portion of the rod may have two opposite sides that are outwardly convex, for example, in the shape of circular arcs, each connecting one of the sides including a groove to the opposite side. In cross-section, the or each groove may have a contour in the shape of a circular arc, for example.
In other embodiments, the housing may have a cross-section that tapers progressively towards its end wall, said taper matching the divergence desired for the bristles. The end wall of the housing may include a recess in which the bristles are fixed, and which opens out into a portion of the housing which flares out towards the opening of the housing, the portion enabling the bristles to splay apart from one another so as to impart a wider shape to the brush.
In certain embodiments, the housing may be arranged so that the bristles extend outside the housing over a width, measured parallel to the long axis X, that is greater than the width of the rod at the housing. A relatively wide brush is thus obtained.
According to some embodiments, the length of the portion of the bristles which projects from the housing of the rod can lie in the range of about 5 millimeters (mm) to about 20 mm, for example. In certain embodiments, the free ends of the bristles may substantially describe an arc of a circle, having a radius of curvature lying in the range of about 2 mm to about 15 mm, for example, and in particular in the range of about 4 mm to about 10 mm. According to certain embodiments, the width of the opening of the housing, measured perpendicularly to the long axis X, may be no greater than about 2 mm.
Close to the longitudinal ends along the long axis X of the housing, the walls of the rod may be relatively thin. Thus, in an embodiment of the invention, the rod may have a wall thickness around the housing that is smaller when measured at a longitudinal end of the housing than when measured mid-way along the housing.
Still in a particular embodiment, the thickness of the wall extending around the housing passes through a minimum in the portions that are adjacent to the longitudinal ends of the long axis of the housing. In another particular embodiment, at its widest point, the portion of the rod that is immersed in the substance contained in the receptacle when the applicator is in place on said receptacle may be no greater than to 5 mm. In certain embodiments, the rod may be arranged so as to be fixed to a closure cap of the receptacle; in a variant, the rod may be made in a single integral piece with a closure cap of the receptacle, by molding plastics material.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be better understood on reading the following detailed description of non-limiting embodiments thereof, and on examining the accompanying drawings, in which:
FIG. 1 is a side, elevational, cross-sectional view of a device in accordance with one embodiment of the present invention for applying a substance to the nails;
FIG. 2 is a side, elevational, cross-sectional fragmentary view of the applicator shown in the device of FIG. 1 ;
FIG. 3 is a side, elevational, cross-sectional view of the rod of the applicator shown in FIG. 1 ;
FIG. 4 shows a detail of the housing receiving the bristles of the brush;
FIG. 5 is a side, elevational, cross-sectional partial view taken along section V-V in FIG. 4 ;
FIG. 6 is a sectional view on V-V of variant embodiment of the end portion of the rod;
FIG. 7 is a sectional view on V-V of variant embodiment of the end portion of the rod;
FIG. 8 is a sectional view on V-V of variant embodiment of the end portion of the rod;
FIG. 9 is a sectional view on V-V of variant embodiment of the end portion of the rod;
FIG. 10 is a sectional view on V-V of variant embodiment of the end portion of the rod;
FIG. 11 is a sectional view on V-V of variant embodiment of the end portion of the rod;
FIG. 12 is a sectional view on V-V of a variant embodiment of the end portion of the rod;
FIG. 13 shows a variant configuration of the housing, showing a different distribution of the bristles outside the rod;
FIG. 14 shows a variant configuration of the housing, showing a different distribution of the bristles outside the rod;
FIG. 15 shows, in isolation, an end portion of the bristles of the brush; and
FIG. 16 is a fragmentary longitudinal section of the rod made integrally with a cap.
DETAILED DESCRIPTION
Before describing several exemplary embodiments of the invention, it is to be understood that the invention is not limited to the details of construction or process steps set forth in the following description. The invention is capable of other embodiments and of being practiced or carried out in various ways.
FIG. 1 shows an exemplary embodiment of a device 1 for applying a substance to the nails, for example, a nail varnish V, the device comprising a receptacle 2 containing the varnish V, and an applicator 3 comprising a rod 4 made of plastics material, provided at one end with a flat brush 5 , and at the other end with a handle member 10 also constituting a closure cap of the receptacle 2 . In the embodiment shown in FIG. 1 , the receptacle 2 also contains a bead 6 , e.g. a metal ball-bearing, enabling the varnish V to be homogenized before application, by shaking the device 1 .
In FIGS. 1 to 3 , it can be seen that the top end of the rod 4 has a skirt 8 enabling it to be fixed in a housing of the cap 10 , said cap being configured so as to be screwed onto the neck 11 of the receptacle 2 . A collar 12 is formed at the base of the skirt 8 so as to bear against the top edge of the neck 11 when the applicator is in place on the receptacle 2 .
Beneath the collar 12 , the rod 4 includes a cone-shaped portion 13 suitable for contributing to sealing the closure of the receptacle 2 when the applicator 3 is in place on said receptacle. Sealing could also be obtained through cooperation between the surface of the cap 10 and of the neck of the receptacle. The rod 4 also includes a bottom end portion 14 which is provided with a housing 15 inside which the bristles of the brush 5 are held, e.g. by stapling, gluing, heat sealing, or overmolding.
As can be seen in FIG. 4 , the free end of the rod 4 may be beveled at 20 . In the example shown, the rod 4 includes two opposite longitudinal grooves 18 extending along a major fraction of its length up to its distal end 17 . In the embodiment shown, the housing 15 has an opening of rectangular cross-section of elongate shape with a long axis X perpendicular to the longitudinal axis of the rod 4 . In the embodiment under consideration, the outside contour of the rod 4 and the housing 15 are symmetrical about the axis X and about a mid-axis Y perpendicular to the axis X.
It can be seen in FIG. 5 that the wall thickness of the material surrounding the housing 15 is not constant. Apart from the grooves 18 , the outside contour 16 of the rod 4 is convex, when said rod is observed in cross-section. More particularly, in the embodiment under consideration, the contour of the rod 4 is defined in the grooves 18 by circular portions 16 a , the portions 16 a being united at their ends by circular portions 16 b that are outwardly convex and that are of smaller radius of curvature than the portions 16 a.
As can be seen in FIG. 4 , the housing 15 can have a cross-section which tapers towards the end wall 19 of the housing. The bristles of the brush 5 splay apart when the brush is applied to a nail. Depending on the shape of the housing 15 , a narrower or wider bundle of bristles can be obtained, as shown in FIGS. 13 and 14 .
It can be seen in FIG. 13 that by providing a housing 15 with a substantially constant cross-section, a brush is obtained having bristles that are relatively close together, whereas by providing the housing 15 with an outwardly flaring shape, the bristles are able to splay further apart from one another so as to form a relatively wide bundle.
In its end wall, the housing 15 can be made with a recess 15 a in which the bristles are secured to the rod. The recess 15 a can open out into a portion 15 b which flares out towards the open end of the housing 15 , enabling the bristles to splay apart from one another.
As can be seen in FIG. 14 , the housing 15 can thus be made in such a manner that the maximum transverse dimension l 2 of the brush, measured parallel to the long axis X, is greater than the transverse dimension l 1 of the rod at the housing 15 .
As can be seen in FIG. 15 , the free ends of the bristles of the brush 5 can be situated along a substantially circular curve C, for example. In a variant, the free ends of the bristles could be situated substantially along a straight line, for example. The length l of the portion of the bristles which projects from the housing 15 lies in the range of about 5 mm to 20 mm, for example.
The device 1 can be used as follows. The user shakes the receptacle 2 so as to enable the bead to homogenize the varnish V, and then the user unscrews the cap 10 and uses the brush 5 to apply the varnish.
When the applicator 3 is removed from the receptacle 2 , substance is present on the rod 4 and said substance flows by gravity towards the brush 5 . The thickness or depth of substance is greater in the grooves 18 , which can retain more substance by capillarity. The substance preferably flows into the central region of the brush, thereby enabling it to be spread more easily and more precisely.
It will be understood of course that the invention is not limited to the embodiment described above. In particular, it is possible to modify the shape of the housing and/or the shape of the end portion of the rod in which said housing is made. By way of example, FIGS. 6 to 12 show various, non limited examples of possible shapes of the housing, from among other possible shapes.
It can be seen in FIG. 6 that the rod can include a single groove 18 only. It can be seen in FIG. 7 that the opening of the housing can have a cross-section that is not rectangular but oblong, e.g. elliptical. It can be seen in FIG. 8 that the opening of the housing can have a cross-section having two slight concavities 15 c in its long sides, the two concavities being less pronounced, however, than the concavities formed by the grooves 18 .
It can be seen in FIG. 9 that the grooves 18 can be relatively narrow, so as to increase further the retention of substance by capillarity, for example. It can be seen in FIG. 10 that the grooves 18 can have a triangular profile in cross-section. FIG. 11 illustrates the fact that the wall thickness e 1 in the vicinity of the longitudinal ends of the housing 15 can be smaller than the wall thickness e 2 substantially mid-way along the housing 15 . If necessary, the thickness e 1 can correspond to a minimum. A small thickness e 1 enables a housing 15 to be made to be longer along the long axis X, thereby enabling a brush to be obtained that is very wide or that is capable of widening easily. FIG. 12 shows the possibility of having two grooves 18 of different shapes. The rod 4 can also be made in a single integral piece with the closure cap of the receptacle, as shown in FIG. 16 .
Although the invention herein has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present invention. It is therefore to be understood that numerous modifications may be made to the illustrative embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims and their equivalents.
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An applicator for applying a substance to nails is disclosed. The applicator comprises a rod having an end portion, the end portion having a housing, the housing having an opening of oblong cross-section with a long axis, the rod having a wall of varying thickness around the housing. In the end portion, the rod has a cross-section having an outer contour that is not concave, with the exception of one or more grooves situated opposite each other.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a method for fabricating transistor, and more particularly, to a method for fabricating metal gate transistor.
2. Description of the Prior Art
In the field of semiconductor fabrication, the use of polysilicon material is diverse. Having a strong resistance for heat, polysilicon materials are commonly used to fabricate gate electrodes for metal-oxide semiconductor transistors. The gate pattern fabricated by polysilicon materials is also used to form self-aligned source/drain regions as polysilicon readily blocks ions from entering the channel region.
However, devices fabricated by polysilicon still have many drawbacks. In contrast to most metal, polysilicon gates are fabricated by semiconductor materials having high resistance, which causes the polysilicon gate to work under a much lower rate than other metal gates. In order to compensate for slightly lowered rate of performance, a significant amount of silicides is applied during the fabrication of polysilicon processes, such that the performance of the device could be increased to an acceptable level.
Gate electrodes fabricated by polysilicon also causes a depletion effect. In most circumstances, the optimum doping concentration for polysilicon is between about 2×20 20 /cm 3 and 3×10 20 /cm 3 . As most gate electrodes have a doping concentration of at least 5×10 21 /cm 3 , the limited doping concentration of polysilicon gates often results in a depletion region at the interface between the gate and the gate dielectric layer. This depletion region not only thickens the gate dielectric layer, but also lowers the capacitance of the gate and ultimately reduces the driving ability of the device.
In order to resolve this issue, work function metal gates have been developed to replace conventional polysilicon gates. The conventional approach for fabricating metal gates typically forms a dummy gate composed primarily of polysilicon on a substrate, removes the polysilicon material of the dummy gate through dry etching or wet etching, and then deposits a metal into the depleted dummy gate for forming a metal gate.
However, the conventional approach of depleting the polysilicon material from the dummy gate often damages the gate insulating layer underneath. As a result, another thermal oxidation has to be carried out to form another gate insulating layer afterwards. This not only extends the overall fabrication time but also disrupts the distribution of the dopants within the lightly doped drain or source/drain region. Hence, how to effectively resolve the above issue has become an important task.
SUMMARY OF THE INVENTION
It is an objective of the present invention to provide a method for fabricating metal gate transistor for solving the aforementioned problem.
According to a preferred embodiment of the present invention, a method for fabricating metal gate transistor is disclosed. The method includes the steps of: providing a substrate, wherein the substrate comprises a transistor region defined thereon; forming a gate insulating layer on the substrate; forming a stacked film on the gate insulating layer, wherein the stacked film comprises at least one etching stop layer, a polysilicon layer, and a hard mask; patterning the gate insulating layer and the stacked film for forming a dummy gate on the substrate; forming a dielectric layer on the dummy gate; performing a planarizing process for partially removing the dielectric layer until reaching the top of the dummy gate; removing the polysilicon layer of the dummy gate; removing the etching stop layer of the dummy gate for forming an opening; and forming a conductive layer in the opening for forming a gate.
These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1-5 illustrate a method for fabricating a metal gate transistor according to a preferred embodiment of the present invention.
DETAILED DESCRIPTION
Referring to FIGS. 1-5 , FIGS. 1-5 illustrate a method for fabricating a metal gate transistor according to a preferred embodiment of the present invention. As shown in FIG. 1 , a substrate 12 , such as a silicon substrate or a silicon-on-insulator substrate is provided, in which at least one transistor region 14 is defined on the substrate 12 .
A gate insulating layer (not shown) composed of dielectric material such as oxides or nitrides is then formed on the surface of the substrate 12 . According to an embodiment of the present invention, the gate insulating layer could also be composed of pad oxide or a high-k dielectric layer consisting of HfSiO, HfSiON, HfO, LaO, LaAlO, ZrO, ZrSiO, HfZrO, or combination thereof.
A stacked film (not shown) composed of an etching stop layer, a polysilicon layer, and a hard mask is formed on the gate insulating layer. Preferably, the etching stop layer is composed of a silicon nitride layer having a thickness of less than 100 Angstroms, and the polysilicon layer serving as dummy gate layer preferably has a thickness of about 1000 Angstroms. The polysilicon layer could be composed of undoped polysilicon or polysilicon having N+ dopants therein, and the hard mask could be composed of SiO 2 , silicon nitride, or SiON, which are all within the scope of the present invention.
Next, a patterned photoresist (not shown) is formed on the hard mask, and a pattern transfer is conducted by using the patterned photoresist as mask through single or multiple etching processes to remove a portion of the hard mask, the polysilicon layer, the etching stop layer, and the gate insulating layer. After stripping the patterned photoresist, a dummy gate 24 composed of patterned gate insulating layer 16 , patterned etching stop layer 18 , patterned polysilicon layer 20 , and patterned hard mask 22 is formed on the substrate 12 of the transistor region 14 .
As shown in FIG. 2 , a first stage of spacer formation is carried out by first depositing a dielectric layer composed of silicon nitride or both silicon oxide and silicon nitride on the dummy gate 24 , and then etching back the deposited dielectric layer to form a first spacer 26 on the sidewall of the dummy gate 24 .
Next, a light doping process is performed to form a lightly doped drain. For instance, a patterned photoresist (not shown) is formed on the region outside the transistor region 14 , and an ion implantation is carried out by using the patterned photoresist as mask to implant n-type or p-type dopants into the substrate 12 adjacent to two sides of the dummy gate 24 to form a lightly doped drain 28 .
Next, a second stage of spacer formation is conducted by sequentially depositing a silicon oxide layer 30 and a silicon nitride layer 32 on the substrate 12 and the dummy gate 24 , and then etching back the deposited silicon oxide layer 30 and silicon nitride layer 32 to form a second spacer 34 around the first spacer 26 .
Next, a heavy doping process is performed to form a source/drain region. Similar the above approach of forming the lightly doped drain 28 , a patterned photoresist (not shown) could be formed on regions outside the transistor region 14 , and an ion implantation is carried out by using the patterned photoresist as mask to implant n-type or p-type dopants into the substrate 12 adjacent to two sides of the second spacer 34 . After thermally diffusing the implanted dopants, a source/drain region 36 is formed in the substrate 12 adjacent to two sides of the second spacer 34 , and the patterned photoresist is stripped thereafter.
Next, a silicon substrate etching back process accompanying a selective epitaxial growth (SEG) process could be performed before or after the formation of the aforementioned source/drain region to form an epitaxial layer (not shown) comprising of silicon and other materials partially in the source/drain region. A salicide process is carried out thereafter to forma silicide layer on the source/drain region 36 . As the selective epitaxial growth process and the salicide process are commonly known to those skilled in the art in this field, the details of which are omitted herein for the sake of brevity. Moreover, despite the first spacer, the lightly doped drain, the second spacer, and the source/drain region are formed sequentially in the above embodiment, the order for fabricating the spacers and doping regions could also be adjusted according to the demand of the product, which are all within the scope of the present invention.
Next, an interlayer dielectric layer 38 primarily composed of oxides is formed to cover the entire dummy gate 24 . The interlayer dielectric layer 38 could include nitrides, oxides, carbides, low-k dielectric materials, or combination thereof.
As shown in FIG. 3 , a chemical mechanical polishing (CMP) process or a dry etching process is performed to remove a portion of the interlayer dielectric layer 38 , part of the first spacer 26 , part of the second spacer 34 , and the hard mask 22 such that the top of the polysilicon layer 20 is exposed and substantially even with the surface of the interlayer dielectric layer 38 .
As shown in FIG. 4 , a selective dry etching or wet etching process is carried out by using etchant such as NH 4 OH or TMAH to empty the polysilicon layer 20 of the dummy gate 24 while stopping on the etching stop layer 18 . Next, a wet etching process is performed by using phosphoric acid to remove the etching stop layer 18 composed of silicon nitride. The removal of the etching stop layer 18 preferably forms an opening 40 in the dummy gate 24 while exposing the gate insulating layer 16 underneath.
It should be noted that the present invention preferably forms an etching stop layer 18 composed of silicon nitride between the gate insulating layer 16 and the polysilicon layer 20 . This etching stop layer 18 could be used to protect the gate insulating layer 16 by preventing plasma or etchant used during the removal of polysilicon layer 20 from damaging the gate insulating layer 16 underneath as the polysilicon layer 20 is emptied
Also, as part of the second spacer 34 is composed of silicon nitride, the present embodiment preferably removes part of the silicon nitride layer 32 of the second spacer 34 while the etching stop layer 18 is removed by the wet etching process, as shown in FIG. 4 .
Moreover, as the etching stop layer 18 is preferably composed of silicon nitride, the first spacer 26 is preferably to be fabricated with a material having different etching selectivity from the etching stop layer 18 . By doing so, the wet etching process carried out to remove the silicon nitride etching stop layer 18 would not be used to damage the first spacer 26 adjacent to the etching stop layer 18 simultaneously.
Next, as shown in FIG. 5 , a high-k dielectric layer 42 is formed in the opening 40 to cover the gate insulating layer 16 , the first spacer 26 , the second spacer 34 , and the interlayer dielectric layer 38 . In this embodiment, the high-k dielectric layer 42 is selected from HfSiO, HfSiON, HfO, LaO, LaAlO, ZrO, ZrSiO, HfZrO, or combination thereof.
Next, a work function metal layer (not shown) could be deposited selectively on the surface of the high-k dielectric layer 42 according to the nature of the transistor. If the transistor fabricated were to be a NMOS transistor, a n-type metal layer could be deposited on the high-k dielectric layer 42 , in which the n-type metal layer is selected from a group consisting of TiN, TaC, TaN, TaSiN, and Al. If the transistor fabricated were to be a PMOS transistor, a p-type metal layer could be deposited on the high-k dielectric layer 42 , in which the p-type metal layer is selected from a group consisting of TiN, W, WN, Pt, Ni, Ru, TaCN, and TaCNO.
Next, a conductive layer 44 composed of low resistance material is deposited on the high-k dielectric layer 42 and into the opening 40 . In this embodiment, the conductive layer 44 is selected from Al, W, TiAl, CoWP, or combination thereof. A chemical mechanical polishing process is conducted thereafter to remove a portion of the conductive layer 44 and high-k dielectric layer 42 on the first spacer 26 , second spacer 34 , and interlayer dielectric layer 38 to form a metal gate transistor in the transistor region 14 .
Overall, the present invention preferably forms an etching stop layer composed of silicon nitride between the gate insulating layer and the dummy polysilicon layer. By doing so, the etching stop layer could be used to protect the gate insulating layer from plasma or etchant used during the removal of polysilicon layer. As the gate insulating layer is protected from damage caused by the removal of the polysilicon layer, the present invention also eliminates the need of conducting an additional thermal oxidation to form another gate insulating layer, thereby reducing overall fabrication time and cost substantially.
Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the invention.
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A method for fabricating metal gate transistor is disclosed. The method includes the steps of: providing a substrate, wherein the substrate comprises a transistor region defined thereon; forming a gate insulating layer on the substrate; forming a stacked film on the gate insulating layer, wherein the stacked film comprises at least one etching stop layer, a polysilicon layer, and a hard mask; patterning the gate insulating layer and the stacked film for forming a dummy gate on the substrate; forming a dielectric layer on the dummy gate; performing a planarizing process for partially removing the dielectric layer until reaching the top of the dummy gate; removing the polysilicon layer of the dummy gate; removing the etching stop layer of the dummy gate for forming an opening; and forming a conductive layer in the opening for forming a gate.
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BACKGROUND OF THE INVENTION
The present invention relates to stairway components used in landscaping. Current methods of creating stairs in outdoor settings include the use of landscape timbers, casting of concrete forms in place, or precasting concrete, or by the use of bricks, paving blocks or concrete slabs arranged to serve as stair components. Each of these methods is very labor intensive and is susceptible to large variations in result. One effort to provide prefabricated concrete stair components is disclosed in U. S. Pat. No. 5,479,746. The devices of this patent include an assortment of components which are stacked to create various stairway or platform arrangements. An open-centered elongate block used to receive individual rectangular blocks is offered for sale under the name STAIR STACKER™ by Borgert Products, Inc. and STEP STACKER by Decor Innovative Concrete Systems. This product does not provide any stabilization of the sides of the open block and features a flat face which does not blend with surrounding components of a block retaining wall. Due to the open structure of this prior art stair block, dimensions may vary caused by the lack of predictable spacing between the longer walls during curing of the concrete within the block forms.
SUMMARY OF THE INVENTION
A stair component block constructed of zero slump concrete is formed with a hollow center section surrounded by orthogonal upright walls. Two opposing walls are interconnected with a narrow vertical web which is provided with two or three vertical slots extending from its top edge toward generally the center of the web. Additional vertical slots are formed in the web at the intersections of the web and the opposing walls interconnected by the web. Each of these slots extends from the top edge of the web part way to the bottom of the web. The web is so slotted such that the top part of the web may be easily removed by striking the sides of the top of the web after the block has been placed. The broken pieces of the web can be left within the central opening of the block during installation. The block is then partly filled with compacted granular material with a covering layer of sand up to a level below the block's top edges equal to the thickness of paving blocks or bricks to be placed atop the sand layer. Paving blocks or paving bricks may then be placed within the block above the sand in varying arrangements according to the installer's choice of design. The paving blocks are set such that the tops thereof are generally flush with the tops of the outer walls of the stair block.
The outside vertical corners of the blocks are beveled and the outside faces of the vertical walls are formed with vertical grooves formed therein spaced such that seams between adjoining blocks will appear to be part of a continuous wall. The inner and outer corners of the tops of the upright walls are radiused to provide a rounded step surface for the stair user and to blend and match with the corners of the usual paving block to be installed within the opening of the block. The blocks may be formed of dyed concrete in any of many colors as desired.
It is an object of the invention to provide a stair component for landscaping applications which is factory produced at low cost and high efficiency.
It is a further object to provide an easily installed stairway block which can be used to retain paving blocks in its top section to provide a decorative staircase in landscaping applications.
It is a further object to provide a stairway block which is easily handled by the installer.
It is also an object of the invention to provide a stair block which is stabilized during installation with a transverse stabilizing web.
It is a further object to provide a stairway block which is aesthetically compatible with retaining walls made from blocks.
It is also an object of the invention to provide a stairway block which is easy to use and which may be successfully installed on a “do-it-yourself” basis.
It is also an object of the invention to provide a landscaping stair block with rounded upper corners.
It is further an object of the invention to produce a landscaping stair block which is versatile in arrangement while having an easily removable stabilizing web.
These and other objects of the invention will be understood from examination of the accompanying drawings and the detailed description which follows.
DESCRIPTION OF THE DRAWING FIGURES
FIG. 1 is a front left perspective of the stair block according to the present invention.
FIG. 2 is a top plan view of the stair block of FIG. 1 .
FIG. 3 is a cross section view taken along line 3 — 3 of FIG. 2 .
FIG. 4 is a perspective view of a stair constructed with the stair block of FIG. 1 with paving blocks installed therewithin shown by dashed lines.
FIG. 5 is an exploded perspective view of an embodiment of the mold for making the block of FIGS. 1, 2 , 3 .
FIG. 6 is a cross section of the mold taken along lines 6 — 6 of FIG. 5 .
FIG. 7 is a top plan view of the mold of FIG. 5 .
DETAILED DESCRIPTION OF THE INVENTION
FIGS. 1, 2 , and 3 of the drawings illustrate the preferred embodiment of the invention composite concrete block 2 . The block is preferably of rectangular shape having opposing end walls 6 and 10 joined to opposing sidewalls 4 , 8 , and an open top 12 , with sidewalls 4 and 8 being longer than end walls 6 and 10 . In the preferred embodiment, sidewalls 4 and 8 are approximately fifty percent longer than end walls 6 and 10 . Centrally disposed within block 2 are cavities 14 and 16 which extend from top 12 to the bottom 18 of block 2 . Separating cavities 14 and 16 is web 20 which interconnects opposing sidewalls 4 and 8 approximately midway along each. Web 20 is of a thickness substantially less than the thicknesses of front sidewall 4 and rear sidewall 8 and end walls 6 and 10 and is integrally formed with the sidewalls 4 , 8 and end walls 6 , 10 . Web 20 is provided with a plurality of spaced apart generally vertical narrow voids 22 , 24 , 26 which extend from the top edge 28 of web 20 into the body 30 of web 20 . Preferably void 22 is disposed in web 20 at the intersection of web 20 with sidewall 8 and void 26 is disposed at the intersection of void 20 with sidewall 4 while void 24 is disposed substantially equidistant from voids 22 and 26 . Preferably web 20 is of the same height as sidewalls 4 and 8 and voids 22 , 24 , 26 may extend approximately halfway through the body 30 of web 20 ; however, voids 22 , 24 , 26 must extend into web 20 at least the height of a paving block, that is approximately 2⅝ inches to 3 inches and preferably 3½ inches. When block 2 is set on a generally level granular base, a user may remove the top segments 32 and 34 of web 20 and may discard the broken pieces thereof into cavities 14 and 16 or otherwise dispose of them. The user then may fill cavities 14 and 16 with granular material in suitable rises to a level below the top 12 of block 2 which allows placement of plural paving blocks on the fill such that the tops of the paving blocks are flush with the top 12 of block 2 . The smaller paving blocks may be installed in various patterns as desired by the user.
The exterior vertical surfaces 44 and 48 of sidewalls 4 , 8 respectively are provided with narrow vertical indentations or V-shaped grooves 52 , preferably visually dividing the outer surfaces 44 and 48 into thirds. The outer surfaces 46 and 50 of end walls 6 and 10 respectively are each similarly provided with at least one vertical indentation or v-shaped groove 52 which is generally equidistant from the ends of the end walls 6 , 10 to visually divide end walls 6 , 10 into halves. Each groove 52 is approximately one fourth inch on each side. Each vertical corner 60 , 61 , 62 , 63 of block 2 is provided with a small bevel 64 along its length. The grooves 52 blend visually with the seams created by bevels 64 on horizontally adjacent blocks 2 .
Referring to FIG. 3, it can be seen that the upper outside corners 42 of sidewalls 4 and 8 are rounded along a radius suitable for a stair, approximately a one half inch radius. It should also be understood that the lower ends 54 , 58 of sidewalls 4 and 8 are enlarged slightly and gradually at ramp regions 68 to strengthen the sidewalls 4 and 8 as well as to give a stronger base for resting the block 2 on a pallet during the forming process and to ease the stripping of the block 2 from its mold. Similarly the lower ends 66 , 70 of end walls 6 and 10 are also graduated inwardly. The enlargements of lower ends of sidewalls 4 , 8 , and walls 6 , 10 create ramp regions 68 adjoining the cavities 14 , 16 .
Preferably the length of end walls 6 , 10 is nominally 15⅝ inches while the length of side walls 4 , 8 is nominally 23⅞ inches. The height of each of end walls 6 , 10 and sidewalls 4 , 8 is nominally seven inches. Each wall 4 , 6 , 8 , 10 may alternatively be six and three fourth inches high or eight inches high. The thickness of end walls 6 , 19 and side walls 4 , 8 is nominally one and three fourth inches and each is rounded on a one-half inch radius at its upper corners. Web 20 is nominally one and three sixteenth inches in thickness and extends between sidewalls 4 , 8 . Voids 22 , 24 , 26 are each nominally one-fourth inch wide and extend approximately three and one half inches into web 20 .
FIG. 4 depicts a staircase 40 constructed from blocks 2 arranged such that each next higher course of blocks 2 rests with the front sidewalls 4 thereof on the rear sidewalls 8 of the course of blocks 2 below. The rear sidewalls 8 of block 2 rest on grade. Within blocks 2 are installed a plurality of paving blocks 76 in an array which the user finds aesthetically pleasing. The paving blocks 76 are nominally four inches by eight inches in size and approximately two to three inches in height. The paving blocks 76 are placed upon granular material filled in the cavities 14 and 16 of blocks 2 after the top segments 32 and 34 of webs 20 have been removed, typically by blows with a hammer to the vertical faces of top segments 32 and 34 . The cavities 14 and 16 of blocks 2 are filled with sand or other granular materials to a level such that the tops of the paving blocks 54 are generally flush with the top edges 56 of blocks 2 .
It can also be seen that grooves 52 of front sidewalls 4 of blocks 2 create a uniform appearance when viewed with seams 74 between adjacent blocks 2 in staircase 40 .
FIG. 5, 6 , and 7 illustrate a suitable mold 78 for forming the blocks 2 in a block-making machine.
Generally, the process for making this invention includes block molding the composite concrete block by filling a block mold 78 with zero slump concrete mix and casting the block by compressing the mix in the mold through the application of pressure to the exposed mix at the open upper end of the block mold 78 . Dyes, colorants, pigments and other additives may be added to the mix depending upon the physical characteristics which are desired in the resulting block.
The fill is then loaded into a hopper which transports the fill to the mold 78 within the block machine. The mold 78 generally comprises at least four sides bordering a central cavity 94 . A core member 86 may be placed in the mold cavity 94 prior to loading the mold 78 with block mix. Generally, the core member 86 may be supported by elongate hangers 88 positioned across opposing first 110 and second 112 sidewalls. The mold 78 may comprise any material which will withstand the pressure to be applied to the block fill by the head as is well known in the art.
The walls of the mold box 82 measure the height and width of the resulting blocks. Accordingly, the mold walls must be made of a thickness which will accommodate the processing parameters of block formation given a specific mold composition.
A flat pallet 80 which is vertically displaceable in a conventional block machine is initially seated against the bottom of mold box 82 . Mold box 82 comprises a pair of oppositely disposed generally identical mold box side walls 110 , 112 connected at their ends by end walls 114 , 116 . Each mold box wall 110 , 112 , 114 , 116 is equal in height. The in-facing surfaces 118 of walls 110 , 112 , 114 , 116 are each provided with vertically disposed elongate triangular ribs 90 which are spaced generally proportionally along walls 110 , 112 , 114 , and 116 . Each rib 90 extends from the top to the bottom of walls 110 , 112 , 114 and 116 . At the interior corners 120 of mold 80 are gussets 122 which serve to create bevels 64 on the corners 60 , 61 , 62 , 63 of a formed block 2 . Ribs 90 form the grooves 52 in the surfaces 44 , 46 , 48 and 50 of block 2 .
A surrounding downwardly concave lip 92 slightly overhangs cavity 94 within mold box 82 in order to form a rounded corner on the outside top edges of block 2 .
Resting atop mold box 82 is mold top plate 84 which includes a central opening 96 of rectangular shape which coincides with the shape of cavity 94 of mold box 82 . A surrounding low barrier 126 is fixed upon the top of mold top plate 84 at three sides of its periphery. Multiple slots 98 are provided through mold top plate 84 to receive tabs 100 of hangers 88 .
Hangers 88 are fixedly mounted to core member 86 such that when core member 86 is lowered into cavity 94 of mold box 82 , core member 86 is suspended from hangers 88 and disposed generally equidistant on its sides from mold box sidewalls 110 , 112 , and end walls 114 , 116 . Hangers 88 rest on mold top plate 84 when tabs 100 are received in slots 98 of mold top plate 84 .
Core member 86 is sized such that it may seat on pallet 80 when in place in cavity 96 . Core member 86 is provided around its periphery at its upper outer corners 128 with overhanging shelf 102 which forms inside rounded corners on the block 2 .
Core member 86 is provided with ramp forms 104 at the lower end thereof which recede at an incline from the generally planar sides 130 of core member 86 .
A recess 106 is disposed centrally in core member 86 to permit block mix to enter and form web 20 of block 2 . Bridges 108 extend into recess 106 at the top of core member 86 , each bridge 108 extending downwardly about four inches to form voids 22 , 24 , 26 of web 20 of block 2 . Slits 124 in core member 86 are defined by pairs of bridges 108 and provide fill areas for block mix to enter to form the top segments 32 , 34 of web 20 .
In operation, the mold 78 is generally positioned in a block molding machine atop a removable or slidable pallet 80 . The core member 86 is then placed into the mold box 82 . The mold 78 is then loaded with block mix or fill.
Zero slump block mix may be introduced from a hopper above mold top plate 84 and enters cavity 94 and slits 124 . The mold 78 is agitated vigorously for a brief period after which a scraper (not shown) is drawn across mold top plate 84 to remove excess fill. A conventional stripper head (not shown) is depressed upon the opening 96 of mold top plate 84 to compress the block mix within the mold 78 . Preferably the head is patterned to avoid the support hangers 88 and core member 86 . Thereafter, the stripper head further depresses as the pallet 80 is lowered from beneath the mold box 82 as the molded block 2 is stripped from the mold 78 . The ramp forms 104 facilitate stripping of the block 2 from the mold 78 and strengthen the sidewalls 4 , 8 and end walls 6 , 10 of block 2 as pressure is exerted on the block mix while in the mold.
Once the blocks are formed, they may be cured through any means known to those of skill in the art. Curing mechanisms such as simple air curing, autoclaving, steam curing or mist curing, are all useful methods of curing the block of the present invention. A preferable means for curing blocks is by steam. The chamber temperature is slowly increased over two or three hours and then stabilized. The steam is gradually discontinued and the blocks are held at the eventual temperature, generally around 100-130 degrees F. for two to three hours. The heat is then turned off and the blocks are allowed to cool. In all instances, the blocks are generally allowed to sit for at least twenty-four hours before being stacked or stored.
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A method for molding a block for an outdoor staircase stair includes filling a form with zero slump mix, the form having outer walls and a core member which includes a vertically disposed central recess extending into the core from its lower surface, filling the recess in the core member, agitating the filled form and recess, compressing the top of the mix in the form, passing a compression head through the form to transfer the formed mix to a pallet, and then curing the formed mix in a misting kiln.
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The present application is related to U.S. Pat. Nos. 5,413,999; 5,463,067; 5,420,353; and 5,449,830.
The present application is related to U.S. Pat. Nos. 5,413,999; 5,463,067; 5,420,353; and 5,449,830.
BACKGROUND OF THE INVENTION
The present invention is concerned with a novel intermediate and process for synthesizing compounds which inhibit the protease encoded by human immunodeficiency virus (HIV), and in particular certain oligopeptide analogs, such as Compound J in the Examples below. These compounds are of value in the prevention of infection by HIV, the treatment of infection by HIV and the treatment of the resulting acquired immune deficiency syndrome (AIDS). These compounds are also useful for inhibiting renin and other proteases.
The invention described herein concerns a process to prepare the HIV protease inhibitor J from the 4-picolyl piperazine carboxamide 1 via a two-step procedure. The piperazine 1 is condensed with epoxide 2 to afford the coupled product 3. Removal of the acetonide protecting group of 3 directly affords the HIV-1 protease inhibitor J. ##STR1##
A retrovirus designated human immunodeficiency virus (HIV) is the etiological agent of the complex disease that includes progressive destruction of the immune system (acquired immune deficiency syndrome; AIDS) and degeneration of the central and peripheral nervous system. This virus was previously known as LAV, HTLV-III, or ARV. A common feature of retrovirus replication is the extensive post-translational processing of precursor polyproteins by a virally encoded protease to generate mature viral proteins required for virus assembly and function. Inhibition of this processing prevents the production of normally infectious virus. For example, Kohl, N. E. et al., Proc. Nat'l Acad. Sci., 85, 4686 (1988) demonstrated that genetic inactivation of the HIV encoded protease resulted in the production of immature, non-infectious virus particles. These results indicate that inhibition of the HIV protease represents a viable method for the treatment of AIDS and the prevention or treatment of infection by HIV.
The nucleotide sequence of HIV shows the presence of a pol gene in one open reading frame [Ratner, L. et al., Nature, 313, 277 (1985)]. Amino acid sequence homology provides evidence that the pol sequence encodes reverse transcriptase, an endonuclease and an HIV protease [Toh, H. et al., EMBO J., 4, 1267 (1985); Power, M. D. et al., Science, 231, 1567 (1986); Pearl, L. H. et al., Nature, 329, 351 (1987)]. The end product compounds, including certain oligopeptide analogs that can be made from the novel intermediates and processes of this invention, are inhibitors of HIV protease, and are disclosed in EPO 541,168, which published on May 12, 1993. See, for example, Compound J therein.
Previously, the synthesis of Compound J and related compounds was accomplished via a 12-step procedure. This procedure is illustrated in EPO 541,168. In prior methods, the HIV protease inhibitor J was prepared by coupling of the epoxide intermediate 2 with the Boc-protected piperazine carboxamide 4 to afford the Boc-protected coupled intermediate 5. Deblocking of 5 then afforded a penultimate Compound 6 which was subjected to picolylation to afford J. The disadvantage with this route is that three chemical steps are necessary to convert the epoxide 2 to J. Thus, after deblocking, a separate picolylation step is necessary to effect conversion to J. Since the more reactive 4-position of the piperazine carboxamide must be protected prior to coupling, the most efficient blocking method for the chiral 2-piperazine-t-butylcarboxamide would be the incorporation of the 3-picolyl moiety at this point. However, it was unexpected that the reaction of piperazine 1 with epoxide 2 would be efficient, since piperazine 1 contains three basic amine functions capable of attacking the epoxide 2. The Boo-protected piperazine 4, however, contains only one basic amine function, and thus it was expected that the coupling of 2 and 4 would be straightforward. ##STR2##
The process of the present invention eliminates one step, an advantage for simplifying the already complex synthesis of Compound J. The present process is shorter and highly efficient.
BRIEF DESCRIPTION OF THE INVENTION
The present invention provides an alternative convergent synthesis that eliminates an extra synthetic step and produces higher yields. The product compound J is useful as an inhibitor of HIV protease, renin and other proteases.
DETAILED DESCRIPTION OF THE INVENTION
The present invention provides a process for synthesis of a compound of the structure ##STR3## comprising the steps of: (a) heating for at least one hour a mixture of one equivalent of ##STR4## with about one equivalent of ##STR5## at a temperature range between about 25° C. and about 150° C. , said mixture optionally containing suitable solvent;
(b) deblocking by treatment with acid, and
(c) neutralizing the acid, to give the desired compound.
In one embodiment, the present invention provides a process for synthesis of a compound of the structure ##STR6## comprising the steps of: (a) heating for at least one hour a mixture of one equivalent of ##STR7## with about one equivalent of ##STR8## at a temperature range between about 65° C. and about 85° C. , said mixture optionally containing as solvent methanol or isopropanol or mixture thereof;
(b) cooling the mixture to about 0° C. ;
(c) deblocking with gaseous HCl; and
(d) neutralizing with NaOH, to give the desired compound.
This invention also covers the compound ##STR9##
The coupling can be carried out by heating the piperazine 1 and the epoxide 2 neat or in a variety of solvents. The coupling reaction can be carried out at temperatures ranging from 25° C. to 150° C. , preferred is the range of 50° C. to 120° C. with the most preferred temperatures being 65° C. to 85° C. Desired solvents for this step include esters such as ethyl acetate, isopropyl acetate, n-butyl acetate; acetonitrile; alcohols such as methanol, ethanol, n-propanol, n-butanol, t-butanol, t-amyl alcohol and isopropanol; hydrocarbons such as cyclohexane and toluene: ethers such as THF and DME; and formamides such as DMF. Preferred solvents are alcohols with the most preferred being methanol and isopropanol.
The deblocking of intermediates 3 to J is accomplished by standard methods, i.e., treatment with strong acids such as gaseous HCl in alcoholic solvents or aqueous HCl, with gaseous HCl being the most preferred method.
The products of this invention are useful in the inhibition of HIV protease, the prevention or treatment of infection by the human immunodeficiency virus (HIV), and the treatment of consequent pathological conditions such as AIDS. Treating AIDS or preventing or treating infection by HIV is defined as including, but not limited to, treating a wide range of states of HIV infection: AIDS, ARC (AIDS related complex), both symptomatic and asymptomatic, and actual or potential exposure to HIV. For example, the end-product compounds that can be made from the processes and intermediates of this invention are useful in treating infection by HIV after suspected past exposure to HIV by, e.g., blood transfusion, organ transplant, exchange of body fluids, bites, accidental needle stick, or exposure to patient blood during surgery.
The end-product HIV protease inhibitors are also useful in the preparation and execution of screening assays for antiviral compounds. For example, end-product compounds are useful for isolating enzyme mutants, which are excellent screening tools for more powerful antiviral compounds. Furthermore, such compounds are useful in establishing or determining the binding site of other antivirals to HIV protease, e.g., by competitive inhibition. Thus, the end-product compounds that are made from the processes and intermediates of this invention are commercial products to be sold for these purposes.
The end product HIV protease inhibitor compound J has the structure ##STR10## or pharmaceutically acceptable salts or hydrates thereof. Compound J is named
N-(2(R)-hydroxy-1(S)-indanyl)-2(R)-phenylmethyl-4(S)-hydroxy-5-(1(4-(3-pyridylmethyl)-2(S)-N'-(t-butylcarboxamido)-piperazinyl))-pentaneamide;
[1S-[1α[αS*,γR*,δ(R*)],2α]]-N-(2,3-dihydro-2-hydroxy-1H-inden-1-yl)-2-[[(1,1-dimethylethyl)amino]carbonyl]-γ-hydroxy-α-(phenylmethyl)-4-(3-pyridinylmethyl)-2-piperazinepentaneadmide; or
N-(1(S)-2,3-dihydro-2(R)-hydroxy-1H-indenyl)-4(S)-hydroxy-2(R)-phenylmethyl-5-[4-(3-pyridylmethyl)-2(S)-t-butylcarbamoyl)-piperazinyl]pentaneamide.
HIV protease inhibitor compounds that can be made from the processes of the instant invention are disclosed in EPO 541,164. The HIV protease inhibitory compounds may be administered to patients in need of such treatment in pharmaceutical compositions comprising a pharmaceutical carrier and therapeutically-effective amounts of the compound or a pharmaceutically acceptable salt thereof. EPO 541,164 discloses suitable pharmaceutical formulations, administration routes, salt forms and dosages for the compounds.
The compounds of the present invention, may have asymmetric centers and occur as racemates, racemic mixtures and as individual diastereomers, or enantiomers with all isomeric forms being included in the present invention.
When any variable (e.g., aryl) occurs more than one time in any constituent, its definition on each occurrence is independent of its definition at every other occurrence. Also, combinations of substituents and/or variables are permissible only if such combinations result in stable compounds.
Representative experimental procedures utilizing the novel process are detailed below. These procedures are exemplary only and are not limitations on the novel process of this invention.
EXAMPLE 1
Pyrazine-2-tert-butyl carboxamide 8
______________________________________ ##STR11##2-Pyrazinecarboxylic acid (7) 3.35 kg (27 mol)Oxalyl chloride 3.46 kg (27.2 mol)tert-Butylamine (KF = 460 μg/ml) 9.36 L (89 mol)EtOAc (KF = 56 μg/ml) 27 LDMF 120 mL1-Propanol 30 L______________________________________
The carboxylic acid 7 was suspended in 27 L of EtOAc and 120 mL of DMF in a 72 L 3-neck flask with mechanical stirring under N 2 and the suspension was cooled to 2° C. The oxalyl chloride was added, maintaining the temperature between 5° and 8° C.
The addition was completed in 5 h. During the exothermic addition CO and CO 2 were evolved. The HCl that was formed remained largely in solution. A precipitate was present which is probably the HCL salt of the pyrazine acid chloride. Assay of the acid chloride formation was carried out by quenching an anhydrous sample of the reaction with t-butylamine. At completion <0.7% of acid 7 remained.
The assay for completion of the acid chloride formation is important because incomplete reaction leads to formation of a bis-tert-butyl oxamide impurity.
The reaction can be monitored by HPLC: 25 cm Dupont Zorbax RXC8 column with 1 mL/min flow and detection at 250 nm; linear gradient from 98% of 0.1% aqueous H 3 PO 4 and 2% CH 3 CN to 50% aqueous H 3 PO 4 and 50% CH 3 CN at 30 min. Retention times: acid 7=10.7 min, amide 8=28.1 min.
The reaction mixture was aged at 5° C. for 1 h. The resulting slurry was cooled to 0° C. and the tert-butylamine was added at such a rate as to keep the internal temperature below 20° C.
The addition required 6 h, as the reaction was very exothermic. A small portion of the generated tert-butylammonium hydrochloride was swept out of the reaction as a fluffy white solid.
The mixture was aged at 18° C. for an additional 30 min. The precipitated ammonium salts were removed by filtration. The filter cake was washed with 12 L of EtOAc. The combined organic phases were washed with 6 L of a 3% NaHCO 3 and 2×2 L of saturated aq. NaCl. The organic phase was treated with 200 g of Darco G60 carbon and filtered through Solka Flok and the cake was washed with 4 L of EtOAc.
Carbon treatment efficiently removed some purple color in the product.
The EtOAc solution of 8 was concentrated at 10 mbar to 25% of the original volume. 30 L of 1-propanol were added, and the distillation was continued until a final volume of 20 L was reached.
At this point, the EtOAc was below the limit of detection in the 1 H NMR (<1%). The internal temperature in this solvent change was <30° C. A 1-propanol/EtOAC solution of 3 was stable to reflux atatmospheric pressure for several days.
Evaporation of an aliquot gave a tan solid m.p 87°-88° C. 13 C NMR (75 MHz. CDCl 3 , ppm) 161.8, 146.8,145.0, 143.8, 142.1, 51.0, 28.5.
EXAMPLE 2
rac-2-tert-Butyl-carboxamide-piperazine 9 ##STR12## Materials
Pyrazine-2-tert-butylcarboxamide 8 2.4 kg (13.4 mol) in 1-Propanol solution 12 L 20% Pd(OH) 2 /C 16 wt. % water 144 g.
The pyrazine-2-tert-butylcarboxamide 8/1-propanol solution was placed into the 5 gal autoclave. The catalyst was added and the mixture was hydrogenated at 65° C. at 40 psi (3 atm) of H 2 .
After 24 h. the reaction had taken up the theoretical amount of hydrogen and GC indicated <1% of 8. The mixture was cooled, purged with N 2 and the catalyst was removed by filtration through Solka Floc. The catalyst was washed with 2 L of warm 1-propanol.
It was found that the use of warm 1-propanol during washing of the filter cake improved filtration and lowered the losses of product on the filter cake.
The reaction was monitored by GC: 30 m Megabore column, from 100° C. to 160° C. at 10°C/min, hold 5 min, then at 10° C. /min to 250° C. retention times: 8=7.0 min, 9=9.4 min. The reaction could also be monitored by TLC with EtOAc/MeOH (50:50) as solvent and Ninhydrin as developing agent.
Evaporation of an aliquot indicated that the yield over amidation and hydrogenation is 88% and that the concentration of 9 is 133 g/L.
Evaporation of an aliquot gave 9 as a white solid m.p. 150°-151° C.; 13 C NMR (75 MHz, D 2 O, ppm) 173.5, 59.8, 52.0, 48.7, 45.0, 44.8, 28.7.
EXAMPLE 3
(S)-2-tert-Butyl-carboxamide-piperazine bis (S)-Camphorsulfonic acid salt (S)-10
______________________________________ ##STR13##Materials______________________________________rac-2-tert-Butyl-carboxamide- 4.10 kg (22.12 mol)piperazine 9in 1-Propanol Solution in 25.5 Kg solvent(S)-(+)-10-Camphorsulfonic acid 10.0 Kg (43.2 mol)1-Propanol 12 LAcetonitrile 39 LWater 2.4 L______________________________________
The solution of amine 9 in 1-propanol was charged to a 100 L flask with an attached batch concentrator. The solution was concentrated at 10 mbar and a temperature <25° C. to a volume of ca 12 L.
At this point the product had precipitated from the solution, but went back into a solution when the mixture was heated to 50° C.
Analysis of a homogeneous aliquot indicated that the concentration of 9 was 341 g/L The concentration was determined by HPLC: 25 cm Dupont Zorbax RXC8 column with 1.5 mL/min flow and detection at 210 nm, isocratic (98/2)CH 3 CN/0.1% aqueous H 3 PO 4 . Retention time of 9:2.5 min.
Acetonitrile (39 L) and water (2.4 L) were added to give a clear, slightly brown solution.
Determination of the water content by KF titration and CH 3 CN/1-propanol ratio by 1 H NMR integration showed that the CH 3 CN/1-propanol/H 2 O ratio was 26/8/1.6. The concentration in the solution was 72.2 g/L.
The (S)-10-camphorsulfonic acid was charged over 30 min in 4 portions at 20° C. The temperature rose to 40° C. after the CSA was added. After a few minutes a thick white precipitate formed. The white slurry was heated to 76° C. to dissolve all the solids, the slightly brown solution was then allowed to cool to 21° C. over 8 h.
The product precipitated at 62° C. The product was filtered without aging at 21° C. , and the filter cake was washed with 5 L of the CH 3 CN/1-propanol/H 2 O 26/8/1.6 solvent mixture. It was dried at 35° C. in the vacuum oven with N 2 bleed to give 5.6 Kg (39%) of 10 as a white crystalline solid m.p 288°-290° C. (with decomp.) [α]D 25 =18.9° (c =0.37, H 2 O). 13 C NMR (75 MHz, D 2 O, ppm) 222.0, 164.0, 59.3, 54.9, 53.3, 49.0, 48.1, 43.6, 43.5, 43.1, 40.6, 40.4, 28.5, 27.2, 25.4, 19.9, 19.8.
The ee of the material was 95% according to the following chiral HPLC assay: an aliquot of 10 (33 mg) was suspended in 4 mL of EtOH and 1 mL of Et 3 N. Boc 2 O (11 mg) was added and the reaction mixture was allowed to age for 1 h. The solvent was completely removed in vacuo, and the residue was dissolved in ca. 1 mL of EtOAc and filtered through a Pasteur pipet with SIO 2 , using EtOAc as eluent. The evaporated product fractions were redissolved in hexanes at ca. 1 mg/mL. The enantiomers were separated on a Daicel Chiracell AS column with a hexane/IPA (97:3) solvent system at a flow rate of 1 mL/min and detection at 228 nm. Retention times: S antipode=7.4 min, R=9.7 min.
EXAMPLE 4
Synthesis of (S)-4-(3-Picolyl)-2-tert-butylcarboxamide piperazine (1)
______________________________________ ##STR14##2(S)-tert-Butylcarboxamide piperazine Bis 7.15 g (11 mmol)(+)CSA salt (10)3-Pyridinecarboxaldehyde 1.04 mL (11 mmol)Titanium (IV) isopropoxide 4 mL (13.7 mmol)Sodium cyanoborohydride 0.47 g (7.5 mmol)______________________________________
A slurry of the 2(S)-tert-butylcarboxamide piperazine Bis (+)-CSA salt in 30 mL of 1-propanol was washed twice with 25% NaOH solution and twice with saturated aqueous sodium sulfate. The homogeneous 1-propanol phase is concentrated at reduced pressure to give 1.30 g (94%) of 2(S)-tert-butylcarboxamide piperazine as a white solid. The crude 2(S)-tert-butylcarboxamide piperazine is suspended in 20 mL of toluene and the aldehyde is added followed by the titanium (IV) isopropoxide. The reaction turns dark and after stirring at 20° C. for 2 h, the sodium cyanoborohydride is added. After 18 h of stirring, 50 mL of EtOH is added and the precipitate is removed by filtration and washed with EtOAc. The combined organic phases are evaporated to give a yellow oil (2.3 g), which is chromatographed on SiO 2 (EtOAc/MeOH 50/50). Evaporation of product containing fractions gives 1.20 g of 2(S)-tert-butylcarboxamide-4-(3-pyridylmethyl)-piperazine (40%).
EXAMPLE 5
N-[2(R)-hydroxy-1(S)-indanyl]-5-[(2(S)-tertiary-butylaminocarbonyl)-4-(3-pyridylmethyl)piperazino]-4(S)-hydroxy-2(R)-phenylmethylpentanamide monohydrate (J.H 2 O)
______________________________________ ##STR15## ##STR16## ##STR17##(2S)-4-(3-Picolyl)-2-tert-butylcarboxamide- 7.9 g (28.5 mmol)piperazine (1)[3aS-[3[2S*,3(R*)],3aα,8aα]]-3,3a,8,8a- 10.0 g (26.5 mmol)tetrahydro-2,2-dimethyl3-[3-(2-oxiranyl)-1-oxo-2-(phenylmethyl)propyl]-2H-indeno-[1,2-d]-oxazole (2)tert-amyl alcohol 88 mL(2-methyl-2-butanol)______________________________________
A mixture of 1 (7.9 g, 28.5 mmol) and the epoxide 2 (10 g, 26.5 mmol) in isopropyl alcohol (88 mL) was heated to the reflux point 82° C. and held for 72 h to complete the formation of 3.
The solution of 3 is cooled to 0° C. and treated with anhydrous HCl gas and the mixture is aged between 0°-5° C. for 3 h. The hydrolysis was quenched by the slow addition of 50% NaOH to adjust the pH of the mixture to 12 while keeping the temperature less than 25° C.
The mixture is then partitioned with isopropyl acetate (200 mL) and water (50 mL). The mixture was agitated and the layers were separated and the aqueous phase was reextracted with isopropyl acetate (50 mL).
The isopropyl acetate solution of J is concentrated to about 100 g/L and water is added to saturate the hot isopropyl acetate solution. The mixture was seeded and cooled to afford J (15.1 g. 90%) from epoxide 2.
______________________________________Conversion of Indene Oxide to Cis-1-Amino-2-IndanolMaterials Mol. Wt. Grams or ml Millimoles______________________________________Indene oxide 132 1 ml 8.33Acetonitrile 41 10 ml 244Water 18 2.15 ml 119.4Conc. H.sub.2 SO.sub.4 98 0.92 ml 16.65N KOH 57 3.0 ml 15Dowex 1.9 meq/ml 15 ml wet resin 28.5 meq50 × 4 (H+)Methanol 17 50 ml 50______________________________________
To one ml of indene oxide (8.33 mmoles) dissolved in 10 ml acetonitrile was added 0.15 ml water (8.33 mmoles). The mixture was cooled to 0°-5° in an ice bath. Concentrated sulfuric acid was added dropwise while maintaining the batch temperature below 10°. When all the acid was added and the temperature was allowed to rise to 20°-25°. The clear solution was aged for 30 minutes.
To this mixture was added 2 ml of water and the solution heated for 30 minutes. When the methyl oxazoline was completely converted to cis amino indanol the reaction mixture was cooled to room temperature.
A solution of 5N KOH (3 ml, 15 mmoles) was added. This is 90% of theory for the sulfuric acid. The solution remained acid to litmus. If the pH rises above, 2 re-acylation occurs and the yield of amino indanol is reduced. The white solid (K 2 SO 4 ) was removed by filtration.
Dowex resin 15 ml (wet with acetonitrile) was added with stirring. The stirred resin was aged for 15 minutes and sampled for LC (dilx 50). When the LC peak for amino indanol disappeared, the resin was collected by filtration, washed with acetonitrile and then with methanol.
The wet resin was treated with a solution of 50 ml 1N NH 3 in methanol and the slurry stirred at room temperature for 30 minutes. The resin was again collected by filtration and the methanol/NH 3 saved. Another charge of 1N NH 3 /MeOH (20 ml) was added and the resin re-slurried. After removal of the resin the methanol/NH 3 solutions of the amino indanol were combined and concentrated to remove the NH 3 . Analysis of the final MeOH solution shows 1.0 g (81% yield) cis-1-amino-2-indanol ready for the tartaric acid resolving agent.
EXAMPLE 7
Preparation of racemic indene oxide
Indene (95%, 122 mL) was dissolved in methanol (812 mL) and acetonitrile (348 mL), then filtered. The filtrate was diluted with 0.05M sodium dibasic phosphate (116 mL), then adjusted to pH 10.5 with 1M aqueous sodium hydroxide. Aqueous hydrogen peroxide (35%, 105 mL) was diluted with water (53 mL) and added over 3 h, while maintaining the temperature at 25° C. and the internal pH at 10.5 with 1M aqueous sodium hydroxide (120 mL total).
After 6 h, 1M aqueous sodium metabisulfite was added (26 mL), while maintaining the pH above 8.3 by addition of 1M aqueous NaOH (39 mL). Water (700 mL) was added and the mixture extracted with methylene chloride (580 ml and 300 mL). The combined organic extracts containing indene oxide (117 g) were concentrated to a volume of 600 mL.
EXAMPLE 8
Preparation of (1S, 2R)-indene oxide
The substrate, (1S, 2R)-indene oxide is prepared according to the method described by D. J. O'Donnell, et al., J. Organic Chemistry, 43, 4540 (1978), herein incorporated by reference for these purposes.
EXAMPLE 9
Preparation of cis-1-amino-2-indanol
lndene oxide (117 g) diluted to a total volume of 600 mL in methylene chloride was diluted with acetonitrile (600 mL) and cooled to -20° C. Methanesulfonic acid (114 mL) was then added. The mixture was warmed to 25° C. and aged for 2 h. Water (600 mL) was added and the mixture heated at 45° C. for 5 h. The organic phase was separated and the aqueous phase further heated at reflux for 4 h with concentration to approximately 200 g/L. The solution was adjusted to pH 12.5 with 50% aqueous sodium hydroxide, and then cooled to 5° C. and filtered, dried in vacuo, to provide cis 1-amino-2-indanol.
EXAMPLE 10
Preparation of 1S-amino-2R-indanol
(1,S, 2R)-indene oxide (85% ee,) (250 g, 0.185 mole) was dissolved in chlorobenzene (300 mL) and heptanes (1200 mL) and slowly added to a solution of methanesulfonic acid (250 mL, 0.375 mole) in acetonitrile (1250 mL) at a temperature of less than about -10° C. The reaction mixture was warmed to 22° C. and aged for 1.0 h. Water was added to the mixture and concentrated by distillation until an internal temperature of 100° C. was achieved. The reaction mixture was heated at 100° C. for 2-3 h then cooled to room temperature. Chlorobenzene (1000 mL) was added, the mixture stirred, the organic phase separated. The remaining aqueous phase containing 1S-amino, 2R-indanol (85% ee, 165 g, 60%) was adjusted to pH 12 with 50% aqueous sodium hydroxide and the product collected by filtration and dried in vacuo at 40° C. to yield 1S-amino, 2R-indanol (85% ee, 160 g).
EXAMPLE 11
Preparation of 1S-amino-2R-indanol
(1S, 2R)-indene oxide (85% ee,) (250 g, 0.185 mole) was dissolved in chlorobenzene (300 mL) and heptanes (1200 mL) and slowly added to a solution of fuming sulfuric acid (21% SO 3 , 184 mL) in acetonitrile (1250 mL) at a temperature of less than about -10° C. The reaction mixture was warmed to 22° C. and aged for 1.0 h. Water was added to the mixture and concentrated by distillation until an internal temperature of 100° C. was achieved. The reaction mixture was heated at 100° C. for 2-3 h, then cooled to room temperature. Chlorobenzene (1000 mL) was added, the mixture stirred, the organic phase separated. The remaining aqueous phase containing 1S-amino, 2R-indanol (85% ee, 205 g, 74%) was diluted with an equal volume of acetonitrile. The pH was adjusted to 12.5 with 50% aqueous sodium hydroxide and the organic phase separated. The remaining aqueous phase was extracted with additional acetonitrile. The combined acetonitrile extracts were concentrated in vacuo to provide 1S-amino, 2R-indanol (85% ee. 205 g).
Alternatively, the remaining aqueous phase containing 1S-amino-2R-indanol (85% ee, 205 g, 74%) was diluted with an equal volume of butanol and the pH was adjusted to 12.5 with 50% aqueous sodium hydroxide and the organic phase separated. The organic phase was washed with chlorobenzene. L-tartaric acid was added and water was removed by distillation to crystallize the tartaric acid salt of the amino-indanol.
EXAMPLE 12
Use of benzonitrile
Indene oxide (5 g) was dissolved in benzonitrile (50 mL) at 25° C. and sulfuric acid (98%, 2.25 mL) was added. The mixture was diluted with 5M aqueous sodium hydroxide solution (50 mL) and extracted with methylene chloride. The organic extracts were concentrated in vacuo to give 5.03 g of oxazoline.
EXAMPLE 13
Resolution of cis-1-Amino-2-indanol
Cis-1-Amino-2-indanol (100 g) was dissolved in methanol (1500 mL) and a solution of L-tartaric acid (110 g) in methanol (1500 mL) was added. The mixture was heated to 60° C. and cooled to 20° C. , filtered and dried in vacuo to give 1S-amino, 2R-indanol L-tartaric acid salt as a methanol solvate (88 g).
EXAMPLE 14
Preparation of 1S-Amino--2R-indanol
1S-Amino, 2R-indanol L-tartaric acid salt methanol solvate (88 g) was dissolved in water (180 mL) and heated to 55°-60° C. The solution was clarified by filtration and the pH adjusted to 12.5 with 50% aqueous sodium hydroxide. The mixture was cooled to 0°-5° C. over 2 h, then aged at that temperature for 1 h, filtered, washed with cold water and dried in vacuo at 40° C. to yield 1S-amino, 2R-indanol (100% ee, 99% pure, 37 g).
EXAMPLE 15
Conversion of 1,2 indanol to cis-1-amino-2-indanol
______________________________________ ##STR18##Materials Mol Wt Grams or ml Millimoles______________________________________1,2 indane diol 150 300 mg. 2acetonitrile 41 2.5 ml 47.3water 18 0.04 ml 2sulfuric acid 98 0.22 ml 45N KOH 57 1.6 ml 8.0Dowex 10 ml50 × 4 (H+)methanol (1 m NH3) 30 ml______________________________________
To 300 mg indane diol dissolved in 3 ml of acetonitrile containing 0.04 ml water was added dropwise at 0°-10° C. a volume of 0.22 ml of concentrated H 2 SO 4 . After the addition was complete the ice bath was removed and the batch warmed to room temperature. After a 30 minute age the clear solution was sampled for Ic assay (dilx 500). When all the glycol was consumed, the solution was treated further with water and heated to reflux on a steam bath to hydrolyze the oxazoline.
When Ic analysis showed hydrolysis complete, 1.6 ml 5N KOH was added to neutralize the sulfuric acid. Potassium sulfate was filtered from the solution.
The filtrate was assayed for cis amino indanol and contained 196 mg (66%, of theory, which is also 75% corrected for unreacted starting material). The solution was passed over 10 ml of Dowex 50×4 (H+). The column spents were checked for product. All the amino indanol was adsorbed. After washing the resin with methanol, the product was eluted with a solution 1M in NH 3 (dry). The ammoniacal methanol was concentrated to remove the NH 3 and the final solution of amino-indanol ready for resolution was assayed. (175 mg, or 59% of theory when uncorrected for unreacted glycol).
EXAMPLE 16
Preparation of Indanol Reactants
Compounds (±)-trans-2-bromo-1-indanol were prepared by methods of S. M. Sutter et al., J. Am. Chem. Soc., 62, 3473 (1940); and D. R. Dalton et al., J. C. S. Chem. Commun., 591 (1966). Compounds (+)-trans-2-bromo-1-indanol and cis- and trans-1,2-indandiols were prepared by the methods of M. Imuta et al. J. Org. Chem., 43, 4540 (1978).
EXAMPLE 17
Preparation of cis-1-amino-2-indanol from trans-2-bromo-1-indanol
Trans-2-bromo-1-indanol (10 g, 46.9 mmole diluted in 100 mL of acetonitrile containing 0.8 mL water) was cooled to -5° C. and concentrated sulfuric acid (5.2 mL) was added. The mixture was aged for 1 h, then 5M aqueous potassium hydroxide was added to adjust the pH to 11. The reaction mixture was filtered, removing the potassium sulfate salts. The aqueous acetonitrile filtrate was adjusted to pH less than 2 with sulfuric acid and heated to 80°-100° C. , removing acetonitrile by distillation to provide an aqueous solution of cis-1-amino-indanol. The solution was concentrated to a volume of 20 mL, then adjusted to pH 12.5 with potassium hydroxide. The product crystallizes, was filtered and dried in vacuo to provide cis-1-amino-2-indanol (4.25 g).
EXAMPLE 18
Preparation of cis-1S-amino-2R-indanol from cis-(1S,2R)-indandiol
Cis-(1S,2R)-indandiol (1 g) was dissolved in acetonitrile (10 mL), cooled to 0° C. and concentrated sulfuric acid (1.0 mL) was added. The mixture was aged for 40 minutes with warming to 20° C. Water (0.8 mL) was added and the mixture was heated to reflux. Aqueous 5M potassium hydroxide (1.6 mL) was added to adjust the pH to more than 11 and the resulting solid (potassium sulfate) removed by filtration to provide an aqueous solution of the cis-1S-amino-2R-indanol (0.79 g, 66% yield).
EXAMPLE 19
Preparation of cis-1-amino-2-indanol from trans-1,2-indandiol
Trans-1,2-indandiol (1.5 g) was dissolved in acetonitrile (25 mL) cooled to 0° C. , and concentrated sulfuric acid (1.1 mL) was added. The mixture was gradually warmed to 20° C. and aged to 3 hours. Water (2 mL) was added and the mixture heated to reflux. Concentrated aqueous sodium hydroxide was added to adjust the pH to 12. The resulting solid was removed by filtration to provide an aqueous acetonitrile solution of cis-1-amino-2-indanol (1.02 g, 63% yield).
EXAMPLE 20
Preparation of cis-1-amino-2-indanol from cis-1,2-indandiol
Cis-1,2-indandiol (1.0 g) was dissolved in acetonitrile (20 mL). cooled to -40° C. and fuming sulfuric acid (21% SO 3 , 0.8 mL) was added. The mixture was aged for 1 hour with gradual warming to 0° C. Water was added and the mixture heated to 80° C. for 1 hour to provide an aqueous solution of cis-1-amino-2-indanol.
EXAMPLE 21
Preparation of Amide 14
______________________________________ ##STR19## ##STR20## ##STR21##(-)-cis-1-aminoindan-2-ol (11) 900 g 6.02 mol(99.7 wgt. %, 99.9 area %, >99.5% ee)sodium carbonate monohydrate 760 g 6.13 moldiethoxymethane (DEM) 56.3 L3-phenylpropionyl chloride (13) 1.05 kg 6.23 molmethanesulfonic acid (MSA) 18.6 g 0.19 mol2-methoxypropene (95% by GC) 1.28 L 13.3 mol5% aqueous NaHCO.sub.3 10.8 Lwater 26.2 L______________________________________
A slurry mixture consisting of (-)-cis-1-aminoindan-2-ol (11. 900 g, 6.02 mol) in 40 L of DEM and aqueous sodium carbonate solution (760 g, 6.13 mol, of Na 2 CO 3 .H 2 O in 6.4 L of water) in a 100L reactor with four inlets, equipped with a thermocouple probe, mechanical stirrer, and a nitrogen inlet adapter and bubbler, was heated to 46°-47° C. and aged for 15 minutes. The reaction mixture was heated to 46°-47° C. and aged for 15 minutes to insure dissolution of the solids. The aqueous phase had a pH of 11.5. Neat 3-phenylpropionyl chloride 13 (1.05 kg, 6.23 mol) was added over 2 h between 47° C. to 59° C. The internal temperature increased from 47° C. to 59° C. during the addition of 13; the hydroxyamide 12 crystallized out of solution during the acid chloride addition. After the addition was complete, the reaction mixture was aged at 59° C. for 0.5 h and then warmed to 72° C. to insure dissolution of the solids. The temperature was increased to 72° C. to dissolve the hydroxyamide so that a homogeneous sample can be obtained for HPLC assay and to simplify the phase cuts. Progress of the reaction was monitored by HPLC analysis: 60:40 Acetonitrile/5.0 mM of each KH 2 PO 4 and K 2 HPO 4 . Approximate retention times:
______________________________________retention time (min.) identity______________________________________4.1 hydroxy amide 126.3 cis-aminoindanol 1112.5 ester amide by product______________________________________
After complete acid chloride addition and 0.5 h age at 72° C. , the HPLC assay of the reaction mixture showed ˜0.6 area % of 11, ˜0.2 area % of ester amide by product and 98.7 area % of hydroxyamide. The hydroxy amide 12 was not efficiently rejected in the isolation of acetonide 14. The aqueous phase was separated and the organic phase was washed twice with 4.5 L of water. The washed organic phase was concentrated and dried via atmospheric azeotropic distillation. The initial volume of ˜40 L was concentrated to 27 L . A total of 16 L of fresh DEM was charged to the still and the batch was concentrated at 88° C. to 89° C. to 40 L .
The dried DEM slurry of hydroxyamide 12 was treated with 1.28 L of 2-methoxypropene followed by 18.6 g of MSA at 30° C. The addition of MSA in absence of 2-methoxypropene resulted in the formation of an amine ester. This impurity reconverts to hydroxyamide 12 during the basic work up at the end of the acetonide formation. The pH of 1.0 mL sample diluted with 1.0 mL water was found to be 2.8-3.0. The resulting mixture was aged at 39° C. to 40° C. for 3 h. The acetonide formation was monitored by HPLC analysis using the same conditions as described above in this example. Approximate retention times:
______________________________________retention time (min.) identity______________________________________4.1 hydroxy amide 126.9 methylene ketal impurity9.0 acetonide 1412.5 ester amide by product______________________________________
The mixture was aged at 38°-40° C. until 12 is ≦0.4 A %. A typical HPLC area % profile is as follows: 0.4 area % of hydroxyamide 12, 96.9 area % of acetonide 14, 0.2 area % of ester amide by product, 1.1 area % of methylene ketal impurity. The reaction mixture was cooled to 24° C. and quenched with 10.8 L of 5% aqueous sodium bicarbonate solution. The aqueous phase was separated and the organic phase was washed twice with 10.8 L of water. The pH of the water wash was 7.6. If the pH was too low, the acetonide group could be hydrolyzed back to give the hydroxyamide 12. The washed organic phase (34.2 L) was concentrated via atmospheric distillation at 78° C. to 80° C. to final volume of 3.5 L . The acetonide concentration was made ˜525 g/L to minimize isolation losses. The hot DEM solution of 14 was allowed to cool to 57° C. , seeded with 0.5 g of 14 and further cooled to 0° C. and aged for 0.5 h. The batch started to crystallize out of solution between 53° C. to 55° C. The product was isolated by filtration and the wet cake was washed with cold (0° C.) DEM (300 mL). The washed cake was dried under vacuum (26" of Hg) at 30° C. to afford 1.74 kg of acetonide 14 (90%, >99.5 area % by HPLC).
EXAMPLE 22
Preparation of Acetonide 14 from (11. tartaric acid) salt
______________________________________(-)-cis-1-aminoindan-2-ol tartrate salt 100 g 297 mmolmethanol solvate(44.3 wt. % of free base 11)sodium carbonate monohydrate 63.76 g 514 mmoldiethoxymethane (DEM) 2.83 L3-phenylpropionyl chloride (13) 52.7 g 312 molmethanesulfonic acid (MSA) 0.95 g 9.86 mmol2-methoxypropene (95% by GC) 63 mL 658 mmol5% aqueous NaHCO.sub.3 520 mLwater 1.32 L______________________________________
A slurry mixture consisting of (-) 11.tartrate salt methanol solvate (100 g, 44.3 g of free base, 297 mmol) in 2.0 L of (DEM) and aqueous sodium carbonate solution (63.8 g, 514 mmol, of Na 2 CO 3 .H 2 O in 316 mL of water) in a 5.0 L reactor with four inlets, equipped with a thermocouple probe, mechanical stirrer, and a nitrogen inlet adapter and bubbler, was heated to 50° C. Heating the reaction mixture to 60° C. did not dissolve all the solids. Neat 3-phenylpropionyl chloride 13 (52.7 g, 312 mmol) was added over 30 min at 50° C. and the mixture was aged at 50° C. for 15 min. Progress of the reaction was monitored by HPLC analysis: 60:40 Acetonitrile/5.0 mM of each KH 2 PO 4 and K 2 HPO 4 , 1.0 mL/min. Approximate retention times:
______________________________________retention time (min.) identity______________________________________4.1 hydroxy amide 126.3 cis-aminoindanol 1112.5 ester amide by product______________________________________
After complete acid chloride addition and 15 min. age at 50° C. , the HPLC assay of the slurry mixture showed ˜0.1 area % of 11. After this point, the reaction mixture was heated to 75° C.
The temperature was increased to 75° C. to dissolve the hydroxyamide 12 in DEM and simplify the phase separations. The aqueous phase was separated and the organic phase was washed twice with water (250 mL). The sodium tartrate was removed in the aqueous phase. The first aqueous cut had a pH of 8.98. The pH of the two water washes were 9.1 and 8.1, respectively. The washed organic phase was concentrated and dried via atmospheric distillation. Approximately 1.0 L of distillate was collected and 750 mL of fresh DEM was charged back to the distillation pot. The atmospheric distillation was continued until another 350 mL of distillate was collected. The solution KF was 93 mg/L. The dried DEM solution was cooled to 30° C. and treated with 63 mL of 2-methoxypropene followed by 0.95 g of MSA. The pH of 1.0 mL sample diluted with 1.0 mL water is 3.2. The reaction mixture was aged at 35°-42° C. for 2 h. The acetonide formation was monitored by HPLC analysis using the same conditions as described above in this Example. Approximate retention times: same as above. The mixture is aged at 38°-40° C. until 12 is ≦0.7 A %. A typical HPLC area % profile is as follows: 0.4 area % of hydroxy amide, 96.9 area % of acetonide 14, 0.2 area % of ester amide by product, 1.1 area % of methylene ketal impurity. The reaction mixture was cooled to 20° C. , filtered to remove the cloudy appearance and quenched with 520 mL of 5% aqueous sodium bicarbonate solution. The aqueous phase was separated and the organic phase was washed with 500 mL of water. The pH of the water wash is 7.4. The washed organic phase (˜2.0 L) was concentrated via atmospheric distillation at 78° C. to 80° C. to final volume of 1.0 L . The acetonide concentration in the isolation was maintained at ˜525 g/L to minimize isolation losses. The hot DEM solution of 14 was allowed to cool to 50°-52° C. , seeded with 100 mg of product and further cooled to 5° C. and aged for 20 min. The batch started to crystallize out of solution at 50° C. The product was isolated by filtration and the wet cake was washed with cold (0° C.) DEM (2×40 mL). The washed cake was dried under vacuum (26" of Hg) at 30° C. to afford 83.8 g of acetonide 14 (87.9%, >99.5 area % by HPLC).
EXAMPLE 23
Preparation of Acetonide 14 (Isopropyl Acetate Solvent)
______________________________________(-)-cis-1-aminoindan-2-ol (11) 80 g 535 mmol(98.5 wgt. %)isopropyl acetate (IPAC) 1.2 Lwater 560 mL5N sodium hydroxide 116 mL 580 mmol3-phenylpropionyl chloride (13) 90.8 g 539 mmolmethanesulfonic acid (MSA) 1.1 mL 17.0 mmol2-methoxypropene (95% by GC) 119 mL 1.24 mol5% aqueous NaHCO.sub.3 950 mLwater 400 mLmethyl cyclohexane 2.25 L______________________________________
A mixture of of (-)-cis-1-aminoindan-2-ol 11 (80 g, 535 mmol) in 1.2 L of IPAC and 560 mL of water was treated with 5 (90.8 g, 539 mmol) while the pH maintained between 8.0-10.5 at 70°-72° C. with 5N sodium hydroxide (116 mL, 580 mmol).
Progress of the reaction was monitored by HPLC analysis: 60:40 Acetonitrile/5.0 mM of each KH 2 PO 4 and K 2 HPO 4 . Approximate retention times:
______________________________________retention time (min.) identity______________________________________4.1 hydroxy amide 126.3 cis-aminoindanol 1112.5 ester amide by product______________________________________
At the end of the reaction, the aqueous phase was separated and the organic phase was washed with water (400 mL) at 72° C. -73° C. The pH of the aqueous phase and the aqueous wash was 8.1 and 7.9, respectively. The wet IPAC phase was dried via atmospheric distillation. A total of 3.0 L of IPAc was charged to lower the batch KF to <100 mg/L. The final volume is ˜1.60 L . The resulting IPAC slurry of hydroxyamide 12 was treated with 2-methoxypropene (119 mL, 1.24 mol) followed by MSA (1.1 mL, 3.2 mole %) at 35° C. -38° C. for 4.5 h. The acetonide formation was monitored by HPLC analysis using the same conditions as described above. The mixture was aged at 38°-40° C. until 12 is ≦0.4 area %. The reaction was filtered to remove the hazy precipitate and the filtrate was quenched into cold sodium bicarbonate solution (950 mL) over 15 min. The aqueous phase was separated and the organic phase was washed with water (400 mL). The sodium bicarbonate solution was cooled to 0° C. -5° C. The pH of the aqueous phase and the aqueous wash was found to be 7.5 and 7.9, respectively. Atmospheric distillation was carried out while the solvent was switched to methylcyclohexane from IPAC. The initial volume before atmospheric concentration was 1.65 L . A total of 1.5 L of methylcyclohexane was added to complete the solvent switch to methylcyclohexane from IPAC. The batch temperature at the end of the solvent switch was 101° C. and the final batch volume was ˜900 mL. The batch was heated to 65° C. -70° C. to insure dissolution of the solids, then cooled to 55° C. , seeded with the product and cooled to 0° C. The mixture was aged at 0° C. for 15 min and the product was isolated by filtration and washed with cold methylcyclohexane (200 ml). The washed cake was dried under vacuum (26" of Hg) at 30° C. to afford 151 g of acetonide 14 (87.5% >99.5 area % by HPLC).
EXAMPLE 24
______________________________________ ##STR22## ##STR23##Acetonide (14) [321.42] 200 g 0.617 mol(99.1 wt. %)Allyl Bromide [120.98] 77.6 g 53.6 mL 0.642 molLDS (FMC 9404) 1.32M in 518 mL 0.684 mol THFCitric acid [192.1] 35.73 g 0.186 molTHF sieve dried 1.43 LWater 1.05 L0.3M H.sub.2 SO.sub.4 1.18 L6% NaHCO.sub.3 1.18 LIPAc______________________________________
The crystalline acetonide 14 (200 g, 0.622 mol, 99.1 wt. %) was dissolved in 1.25 L sieve dried THF (KF=11 mg/L) under nitrogen atmosphere at 25° C. with mechanical stirring. The resulting KF of the solution at this point was 40 mg/L. The solution was subjected to three alternating vacuum/nitrogen purge cycles to thoroughly degas the solution of dissolved oxygen.
Allyl bromide was added to the THF solution. The resulting KF was 75 mg/L. Typical complete conversion (>99.5%) has been obtained with pre-LDS solution KF levels of 200 mg/L with the 10% base excess present in this procedure. The solution was then cooled to -20° C. A THF solution of lithium hexamethyldisilazide (LDS, 1.32M) was added to the allyl bromide/14 solution at such a rate as to maintain the reaction temperature at -20° C. The LDS addition took 30 min. The mixture was aged at -15° to -20° C. and quenched when the conversion was >99%. Analysis of the reaction was carried out by HPLC. Approximate retention times: hydroxyacetonide by product=5.3 min, ethyl benzene=5.6 min, acetonide 14=6.6 min; allyl acetonide 15=11.8 min; epi-15=13.3 min. After 1 h, the reaction had gone to >99.5% conversion. The reaction was quenched by the addition of a solution of citric acid (35.7 g, 0.186 mol) in 186 mL of THF. The mixture was aged at 15° C. for 30 min following the citric acid addition. The mixture was concentrated at reduced pressure (about 28" Hg) to about 30% of the initial volume while maintaining a pot temperature of 11°-15° C. and collecting 900 mL of distillate in a dry ice-cooled trap. The solvent was then switched using a total of 2.7 L of isopropyl acetate (IPAc) while continuing the reduced pressure distillation. The solvent switch was stopped when <1 mole % THF remained by 1 H NMR (see analytical report for GC method). The maximum temperature during the distillation should not exceed 35° C. The crude mixture in IPAc was washed with 1.05 L of distilled water, 1.18 L of 0.3M sulfuric acid. and 1.18 L of 6% aqueous sodium bicarbonate. The volume of the organic phase after the washes was 1.86 L.
The pH of the mixture after the three aqueous washes was 6.5, 1.3 and 8.5. respectively. HPLC analysis of the mixture at this point indicated 93-94% assay yield for 15. The ratio of the desired 15:epi-15 was 96:4 by HPLC (same conditions as above). GC analysis at this point indicated that the hexamethyldisilazane by-product had been completely removed in the workup.
EXAMPLE 25
______________________________________ ##STR24##NCS [133.5] 141.2 g 1.06 molNaHCO.sub.3 [84.01] 36.6 g 0.434 molNaI [149.9] 158.6 g 1.06 molNa.sub.2 SO.sub.3 [126.0] 80 gWater 1.55 L______________________________________
To the allyl amide 15 solution in IPAc from the previous step at 25° C. was added a solution of 36.6 g of sodium bicarbonate in 1.03 L of distilled water and the biphasic mixture was cooled to 5° C. Solid N-chlorosuccinimide (141.2 g, 1.06 mol) was added. There was no exotherm after the addition of NCS. To this mixture was added an aqueous solution of sodium iodide (158.6 g, 1.06 mol) while maintaining the reaction mixture at 6°-11° C. The addition took 30 min, and the mixture became dark. The mixture was warmed to 25° C. and aged with vigorous stirring. Progress of the reaction was monitored by HPLC: same system as above, approximate retention times: iodohydrins 16, epi-16, bis-epi-16=8.1 min; allyl amide 15=11.8 min. Analysis of the mixture by HPLC alter 2.25 h indicated >99.5% conversion. The approximate diastereomer ratio of 16:epi-16:bis-epi-16 in the crude mixture is roughly 94:2:4 at this point when resolution of the components can be obtained on this system. The agitation was discontinued and the layers were separated. To the organic phase was added aqueous sodium sulfite (80 g, 0.635 mol in 400 mL) over 10-15 min. The temperature of the mixture rose from 26°-29° C. after the sodium sulfite addition. The mixture was agitated for 40 min at 25° C. The solution was substantially decolorized after the sulfite wash. The layers were separated; the KF of the organic phase at this point was 25 g/L. The volume of the organic phase was 1.97 L . Quantitative analysis of the mixture by HPLC (same system as above) indicated a 86% overall assay yield of the iodohydrin 11 at this point (corrected for coeluting diastereomers).
EXAMPLE 26
______________________________________ ##STR25##NaOMe [54.02] d = 0.945 25 wt % in MeOH 172 g0.796 mol3% aqueous Na.sub.2 SO.sub.4 1.5 Ln-PrOH______________________________________
The solution of the iodohydrin 16 was concentrated in vacuo (28" Hg) to azeotropically dry the batch. A total of 700 mL of distillate was collected while maintaining a batch temperature of 22°-28° C. The distillate was replaced with 500 mL of IPAc (KF=275 mg/L).
The solution was cooled to 26° C. and 25% NaOMe/MeOH solution (168.1 g) was added over a 10 min period. The temperature dropped to 24° C. after the addition of sodium methoxide. The mixture became darker and a gummy solid briefly formed which redissolved. The mixture was aged for 1 h at 25° C. Analysis of the reaction was carried out by HPLC (same conditions as above), approximate retention times: epoxide epi-2=6.5 min, epoxide 2, bis-epi-2=7.1 min , iodohydrin 16=8.1 min. HPLC analysis indicated 99% conversion of the iodohydrin to the epoxide. After an additional 40 min , 4.1 g of the sodium methoxide/methanol solution was added. After 20 min, HPLC analysis indicated 99.5% conversion. The reaction was quenched by the addition of 366 mL of water at 25° C. which was then agitated briefly (10 min) and the layers were separated. It was subsequently found that extended aging of the reaction and water wash agitation/settling gave substantial back reaction to iodohydrin under these conditions in the pilot plant. This problem is especially acute in the water washes. To eliminate this problem, the reaction was run at 15° C. After >99% conversion was achieved (1 h after NaOMe addition), the mixture was diluted with IPAc (40% of batch volume) and initially washed with an increased volume of water (732 mL) at 20° C. Colder temperatures and more concentrated mixtures can result in the premature precipitation of 2 during the washes. The agitation/settling times were kept to a minimum (10 min/30 min, respectively). In this way, the back reaction could be limited to ≦1%. Crude mixtures containing (97:3) epoxide 2/iodohydrin 16 have been carried forward in the isolation to afford epoxide product containing 0.6% iodohydrin. Epoxide product containing this level of iodohydrin has been carried forward without complication. The organic phase was washed with 3% aqueous sodium sulfate (2×750 mL). The volume of the organic phase was 1.98 L after the washes. The pH of the three water washes was 10.7, 9.4 and 8.6, respectively. HPLC analysis indicated a 86% overall assay yield of epoxide 2 at this point (corrected for 4% co-eluting bis-epi-2). The IPAc solution of epoxide 2 was concentrated at reduced pressure (28" Hg) to a volume of about 600 mL while maintaining the batch at 15°-22° C. The solvent was switched to n-PrOH by adding 750 mL n-PrOH while vacuum concentrating to a pot volume of about 500 mL, maintaining the batch at <30° C. Temperatures>35° C. during the concentration/solvent switch can give an n-propyl ether by-product derived from epoxide 2. Analysis of the solvent composition by 1 H NMR showed <1 mol % IPAc remaining. The thick slurry was cooled to -10° C. over an hour and aged for 45 min. The solids were filtered and washed with 125 mL of cold nPrOH. The product was dried in a vacuum oven at 25° C. to afford 188.5 g of epoxide 2 (98.9 A %, 97.6 wt. %, 0.8 wt. % epi-2, 79.3% yield overall from 14.) Normal phase HPLC (see analytical research memo for procedure) indicated no bis-epi-2 present in the isolated solids.
EXAMPLE 27
Preparation of penultimate 6
______________________________________ ##STR26## ##STR27## ##STR28##2(S)-t-butylcarboxamide-4-N-Boc- 159 g 557 mmolpiperazine 4 (98.9 wt. %, 99.6% ee)epoxide 2 (97.6 wt. %, 1.0% epi-2) 200 g 530 mmolmethanol 1.06 LHCl (g) 194 g 5.32 mmol23% NaOH 740 mLisopropyl acetate 4.0 Lwater 700 mL______________________________________ *corrected for wt. % purity
Solid 2(S)-t-butylcarboxamide-4-t-butoxycarbonyl-piperazine 4 (159 g, 557 mmol) and the epoxide 2 (200 g, 530 mol) were added to a 2 L three neck flask, equipped with a mechanical stirrer, reflux condenser, heating mantle, teflon coated thermocouple and nitrogen inlet. Methanol (756 mL) was added and the resulting slurry was heated to reflux temperature. After 40 min., a homogeneous solution was obtained. The internal temperature during reflux was 64°-65° C. Progress of the reaction was monitored by HPLC analysis: 60:40 acetonitrile/10 mM (KH 2 PO 4 /K 2 HPO 4 ), retention times:
______________________________________retention time (min) identity______________________________________4.8 piperazine 46.6 methyl ether 168.2 epoxide epi-28.9 epoxide 215.2 coupled product 5______________________________________
The mixture was maintained at reflux until epoxide 2 was between 1.2 to 1.5 area % by HPLC analysis. The coupled product at this point was about 94-95 area %. The methyl ether 16 was present at 1.0-1.5 A % at completion. Typical time to achieve this conversion was 24-26 h at reflux. ##STR29##
The mixture was cooled to 5° C. and anhydrous HCl gas (194 g, 5.32 moles, ˜10 equiv.) was bubbled directly into the methanol solution under nitrogen atmosphere while keeping the temperature between 5°-8° C. over 2-3 h. After the addition was complete, the mixture was aged between 5°-8° C. for 1-3 h. Evolution of gas was observed at this point (carbon dioxide and isobutylene). Progress of the reaction was monitored by HPLC analysis: same conditions as above, Approximate retention times:
______________________________________retention time (min) identity______________________________________6.0 Boc intermediate 177.0 cis-aminoindanol 1111.9 penultimate 615.1 coupled product 516.5 lactone 1825.0 acetonide intermediate 19 ##STR30## ##STR31##______________________________________
The mixture was aged at 5° to 8° C. until Boc intermediate 17 is <0.5 area % by HPLC analysis. At this point, penultimate 6 was about 92-93 A %. 11 was <1.0 A % and 18 was 0.6 A % by HPLC analysis. The deblocking was complete after 4 h at 5° C. Cooling and quenching the reaction promptly upon completion limits decomposition of 6 to 11 and 18 under the hydrolysis conditions. ##STR32##
The mixture was cooled to -10° to 15° C. This mixture was then slowly added to a 5 liter flask equipped with a mechanical stirrer containing a cold, stirred solution of DI water (700 mL) and methanol (300 mL) at 0°-2° C. ; the pH of the quenched mixture was maintained between 8.5-9.0 by addition of 23 wgt. % aqueous NaOH solution (giving a highly exothermic reaction) while keeping the temperature between 10°-20° C. The final batch pH was 9.0-9.5.
The mixture was extracted with isopropyl acetate (3.0 L). The mixture was agitated and the layers were separated. The spent aqueous phase was re-extracted with isopropyl acetate (1.0 L). HPLC assay yield of 6 in isopropyl acetate at this point is 94%. The combined organic phase (˜5.0 L) was concentrated under reduced pressure (24-25" of Hg) to a volume of about 1.12 L at a batch temperature of 30°-40° C. The pot temperature during the solvent switch can rise to 40° C. with no penalty in yield or degradation. This solution of crude 6 was then used directly in the next step to afford compound J.
EXAMPLE 28
Preparation of monohydrate
______________________________________ ##STR33## ##STR34##penultimate 6 261 g 499 mmolpotassium bicarbonate 152 g 1.52 molwater 6.1 Lpicolyl chloride 93.3 g 569 mmolisopropyl acetate 3.17 L______________________________________
An isopropyl acetate solution of penultimate (4.96 L; 52.5 g/L of penultimate) was concentrated under reduced pressure to a volume of 1.18 L (260 g, 499 mmol). The batch temperature was maintained between 35° C. to 44° C. while keeping vacuum pressure at 25" of Hg. The methanol content was less than <1.0 vol %. The resulting slurry was treated with an aqueous solution of potassium bicarbonate (152 g in 630 mL of water, 1.59 mol, ˜3.0 equiv.) and heated to 60° C. Then, an aqueous solution of picolyl chloride (93.8 g in 94 mL of water; 572 mmol, 1.14 equiv.(was added over 4 hours. The batch was seeded with J monohydrate after charging 75% of the picolyl chloride charge. The batch temperature was between 60° C. to 65° C.
At the end of the addition, the slurry mixture was aged for 20 h between 60° C. to 65° C. The reaction was complete when the penultimate is <1.0 area % by HPLC analysis. The picolyl chloride level was between 0.5 to 0.8 area %.
The batch was then diluted with 2.5 L of isopropyl acetate and 1.34 L of water and heated to 78° C. The layers were separated and the organic phase was washed with hot water (3×1.34 L) at 78° C. The hot water wash removed the bis-alkylated J and the level was reduced to <0.1 area % by HPLC analysis.
The organic phase was slowly cooled to 75° C. and seeded with J monohydrate (8.0 g) and then further cooled to 4° C. over 2 h. The mixture was filtered to collect the product and the wet cake was washed with cold isopropyl acetate (2×335 mL). The wet cake was dried in vacuo (28" Hg, 22° C.) to afford 273 g of J monohydrate in 79% isolated yield from the epoxide.
While the foregoing specification teaches the principles of the present invention, with examples provided for the purpose of illustration, it will be understood that the practice of the invention encompasses all of the usual variations, adaptations, and modifications, as come within the scope of the following claims and its equivalents.
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A process for making a clinically efficacious HIV protease inhibitor eliminates one step in its synthesis, by an alternative convergent synthesis using 2(S)-4-picolyl-2-piperazine-t-butylcarboxamide as an intermediate.
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This application is a division of application Ser. No. 07/326,924, now U.S. Pat. No. 5,040,036 issued to the applicant of the present application, filed Mar. 22, 1989.
BACKGROUND OF THE INVENTION
The present invention relates generally to nonvolatile semiconductor memory (ROM) and, more particularly, relates to an improved electrically erasable programmable read only memory (EEPROM).
DESCRIPTION OF THE RELEVANT ART
The invention of U.S. Pat. No. 4,845,538 to E. Hazani uses electron tunneling between two polysilicon layers to perform programming and erasure. U.S. Pat. No. 4,763,299 to E. Hazani describes an invention that uses hot electron from the substrate to program and poly-to-poly electron tunneling to erase.
This invention describes an improved process to build embodiments of U.S. Pat. No. 4,845,538, and U.S. patent application Ser. No. 07/327,663, now U.S. Pat. No. 5,047,814 issued to the applicant of the present application filed Mar. 22, 1989.
It also improves on Ultra Violet Light Erasable PROM (UVEPROM) memory cells using split-gate structures which were disclosed in an article by Barnes, et al. entitled "Operation and Characterization of N-channel EPROM Cells", published in Solid State Electronics, Vol. 21, pages 521-529 (1989) and in an article by Guterman, et al. entitled "An Electrically Alterable Nonvolatile Memory Cell Using a Floating-Gate Structure", published in the IEEE Journal of Solid State Circuits, Vol. SC-14, No. 2, April 1979.
More techniques for fabricating a split-gate EPROM are disclosed in U.S. Pat. No. 4,328,565 issued May 4, 1982 to Harari, and in U.S. Pat. No. 4,639,893 issued Jan. 27, 1987 assigned to Waferscale Integration, Fremont Calif. However these patents still leave room for major improvement in the electrical operation of the cell and in reduction in cell size when similar photolithography equipment is used in fabrication.
SUMMARY OF THE INVENTION
One aspect of the invention discloses an operation as an EEPROM with a memory cell size smaller than the cell disclosed in U.S. Pat. No. 4,845,538, however it requires higher programming voltage.
Another embodiment of the present split-gate invention pertaining to UVEPROM (hot electron programming) will improve on the previous art by providing a smaller cell size if the same minimum critical-dimension of photo lithography equipment are used in fabrication of the cell. Also it provides better control of the channel length dimension of the floating gate. It provides a better control over the coupling overlap-area between the drain diffusion and the floating gate in order to minimize this coupling. It provides a better isolation technique between word-lines and between floating-gates in the array so that significant cell-area reduction is achieved. Further improvement on the previous art is in the reduced possibility of punchthrough due to shallower source and drain N+ junctions.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view of a portion of a memory chip containing an array of the first embodiment of the present invention.
FIG. 2 is a cross section view of one of the memory cells of FIG. 1 along line 2--2' of FIG. 1.
FIG. 3 is a cross section illustrating an initial stage of manufacturing of the device of FIG. 2.
FIGS. 4 and 5 illustrate steps in formation of the diffusion bit-lines.
FIG. 6 illustrates the use of nitride to define the drain area of the channel, which will be covered by the floating-gate.
FIGS. 7 and 8 illustrate steps in formation of the floating gate.
FIGS. 9 and 10 illustrate steps in formation of the interpoly-oxide, and the control-gate (word-line).
FIGS. 11A and 11B are section-cuts along lines 12A and 12B of FIG. 10 after application of resists in the fabrication of the device.
FIGS. 12A and 12B are section-cuts along lines 12A and 12B of FIG. 10 after an etching step.
FIG. 13 is a cross section along line 13--13' of FIG. 1 illustrating a later fabrication stage which includes the metal bit-lines.
FIG. 14 is a cross section along line 14--14' of FIG. 1 illustrating a later fabrication stage which includes word-line to word-line isolation near the floating gates.
FIG. 15 is a cross section along line 15--15' of FIG. 1 illustrating a later fabrication stage which includes word-line to word-line isolation where there are no floating gates.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 depicts the overall layout of the array of EEPROM cells. Referring now to FIG. 1, the array is laid out on the major surface 10 of a p doped monocrystalline silicon substrate. A first set of equispaced, vertical N+ regions 12 form the source/drain lines of the array. These source/drain lines are crossed by a first set of equispaced, horizontal polysilicon word lines 14. A second set of floating gate poly layers 18 each include a first region disposed below an associated word line 14.
The word lines 14 and floating gates 18 are formed from separate poly layers that are deposited over the substrate and then selectively etched. Because the floating gates 18 are disposed below the word line 14, the layer utilized to form the floating gate is deposited first and the floating gates are referred to as poly 1 or P1. Similarly, the word lines are often referred to as poly 2 or P2. This terminology is utilized herein. A basic memory cell 19 is defined at the intersection of each source/drain line 12 and word line 14. The structure of a cell will now be described with reference to FIGS. 2 to 15.
FIG. 2 illustrates a cross-sectional view of a memory cell taken along cut 2--2' of FIG. 1. The cell includes a p+ substrate 25 with a p- epilayer 26. A p well 27 is formed over the p- epilayer 26. Two n+ diffused regions 28a and 28b are spaced apart by a trench. An oxide layer 29 covers regions 28a and 28b. The drain area 34a of the trench is filled with an oxide layer 29a and a polycrystalline silicone layer 30. The source area 34b of the trench is covered by an oxide layer 37 and an oxide layer 38 and polycrystalline silicone layer 39. Oxide layer 29 is greater in thickness over the n+ diffused regions 28a and 28b than the thickness of oxide layer 29a over the drain area 34a of the trench. Oxide layers 37 and 38 isolate the polycrystalline region 30 and the polycrystalline layer 39 which covers the upper surface of oxide layer 38 over the source area 34b of the trench and also covers the upper surface of oxide layer 38 over the polycrystalline region 30.
The channel region of the cell is created between the n+ regions 28a and 28b. The n+ regions 28a and 28b form the drain and the source of the transistor respectively. A floating gate is formed by the polycrystalline silicone region 30 over the drain area 34a of the channel. The control gate is formed by the polycrystalline silicone 39 over the source area of the channel 34b and over the floating gate 30.
It was disclosed in U.S. Pat. No. 4,845,538 and in accompanying application Ser. No. 07/327,663, now U.S. Pat. No. 5,047,814 issued to the applicant of the present application, filed Mar. 22, 1989 that the cell may be programmed by holding the drain at a high voltage Vpp while the control gate is held at Vss ground potential. The source may be held at Vss or at half Vpp (1/2*Vpp). This biasing condition ensures that the source area of the channel 34b is not inverted and that there is no current between drain and source. At this voltage conditions the drain voltage is coupled to the floating gate through the capacitance of the overlap area between floating gate 30 and drain diffusion 28a. The floating gate voltage increases to such a level which is higher than the unprogrammed threshold voltage of the cell, thus inverting the drain area of the channel 34a. Once the drain area 34a is inverted it carries the high voltage Vpp of the drain 28a. The capacitive coupling between the drain area 34a and the floating gate is about 5 to 10 times that of the capacitive coupling between the drain 28a and the floating gate.
This sudden increase of Vpp coupling to the floating gate through the drain area 34a brings the floating gate to a voltage which causes reverse electron tunneling from the grounded control gate 39 to the floating gate 30, through the oxide layers 38 and 37. This transfer of electrons which are trapped in the floating gate programs the cell by changing its threshold. The cell may be erased by holding the drain 28a and source 28b at Vss and taking the control gate 39 to high voltage Vpp. This causes forward electron tunneling from the floating gate to the control gate through oxide layers 37 and 38, which brings the cell to an unprogrammed threshold voltage.
Another method of programming the cell may be as a split-gate EPROM. As known the EPROM cell will program when the control gate 39 is at high voltage Vpp, the drain voltage is at high voltage close to Vpp and the source voltage is at Vss ground voltage. This bias condition causes high current flow between drain and source diffusions, which in turn causes electron injection from the substrate into the floating gate through oxide layer 29a. These increase in number of electrons trapped in the floating gate increases the threshold of the cell significantly; thus, it is programmed.
Erasure of the cell may be done electrically by holding the drain and source diffusions at Vss ground potential and taking the control gate to Vpp high voltage. This will cause foreword electron tunneling from the floating gate 30 to control gate 39, thus bring the cell to its initial threshold voltage. Another method of erasure may be by exposing the array to ultraviolet light, a common procedure in the EPROM business.
Another method of erasure when the cell is programmed by hot electrons is by taking the word-line polysilicon control gate to a negative voltage of -16 volts, while grounding the drain and source bit-lines at 0 volts. This will erase all the cells along a selected word lines, because electrons will leave floating gates in these cells due to the rejecting force from the negatively charged word line.
Another method of erasure when the cell is programmed by hot electrons is by tunneling electrons from the floating gate to the drain diffusion through the sidewall oxide which is placed between oxide layer 29 on the drain and oxide layer 29a in FIG. 2. This is done by making the sidewall oxide about 100 Angstrom thin. Erasure in this method takes place when a selected cell's word line is grounded at 0 volt and its drain is taken to about 12 volts.
Another method of programming and erasing the cell is through the thin tunneling sidewall oxide, which was described above, between the floating gate and the drain diffusion. In this method programming takes place when a selected word line is taken to about 15 volts and all source and drain bit-lines are grounded to prevent hot electron programming. Due to voltage coupling from control-gate word-line to the floating gate, electrons will travel from drain diffusion to floating gate and program the cell. Erasure in this method occurs when a selected cell's drain bit-line is taken to 5 volts while its word line is taken to negative voltage of -11 volts, which causes electrons to transfer from the floating gate to the positively biased drain.
Referring to FIG. 3, it illustrates a cross sectional view of the initial fabrication steps, which are commonly used in the art. A p+ doped substrate 25 is a starting material on which a p- epitaxial layer 26 is grown to a thickness of about 15 microns which will have a low resistence of about 10 ohm/cm3. A p well 27 is then implanted using 10E12/cm3 boron for 1800 minutes at 1150 deg. C. to form a 3.5 micron thick layer 27. An n+ Arsenic ions 1.0E16/cm2 are then implanted at 60 KeV and annealed at 850 deg. C. for 120 minutes, thus layer 28 is formed. An oxide layer 29 is then grown to a thickness of 1000 Angstroms at 800 deg. C.
FIG. 4 illustrates a resist 20 patterned in the form of the bit line mask over the oxide 29.
FIG. 5 shows the result of etching the areas of oxide 29 and n+ diffusion 28 not protected by resist 20. The etching step continues until a trench 34 is formed in the p well 27. In an array, the trenches are separated by the n+ areas 28 which form the column bit lines. After removal of the resist, the structure of FIG. 5 will consist of n+ regions 28a and 28b about 600 Angstrom thick, oxide regions 29 about 1000 Angstrom thick and trenches 34 about 2500 Angstrom deep.
FIG. 6 illustrates that 250 Angstrom thermal oxide is grown over the trench area after a threshold voltage implant was implanted to set it at about 0.8 V. A special mask is used to pattern a deposited nitride film 35, such that it is aligned to the center of the n+ diffusion bit line layer 28b. The nitride film 35 covers half of source region 28b and the portion of the trench which will be covered by the control gate and will define the source area 34b. The definition of the source area is done within one alignment tolerance of the photolithography equipment used in fabrication.
Using nitride film 35 to protect the source area 34b of the channel, polysilicon layer 30 is then deposited as illustrated in FIG. 7 for example at 650 degrees C. by low pressure chemical vapor deposition (LPCVD). The polysilicon layer 30 is then doped with phosphorous by passing POCL3 through a chamber at 950 degrees C. for about 15 minutes. An etching of poly-1 is performed using plasma or reactive ion etching to a point where poly-1 covers only the drain area 34a and is removed from all other areas. The nitride film 35 is then removed by chemical stripping and the result is illustrated in FIG. 8.
In one example the floating gate poly-1 30 covers half the trench so that the drain area 34a is about as wide as half the channel. The thickness of the floating gate poly-1 30 at this step of processing is about 3500 Angstrom.
In preparation to forming the interpoly dielectric, a resist 36 is formed over the bit-line oxide 29 to protect it from an etchant that is used to etch oxide 29b over the source area 34b. The resist is defined using the same mask which was used to define the bit-line n+ areas 28. The etchant used here etches oxide much faster then polysilicon, such that floating gate 30 remains in tact. The result of the removal of oxide 29b is illustrated in FIG. 9. This was done in order to keep the gate oxide thickness along the channel 34 about the same even after deposition of the second polysilicon layer 39, which is shown in FIG. 10.
After the removal of oxide 29a and resist 36, the floating gate 30's surface is oxidized in an atmosphere of oxygen and steam at 800 degree C. such that mainly the top surface of layer 30 at the interface with this thermal oxide (not shown) is textured with asperites. After a period of time of oxidation which gives a desired asperity size, the oxide is removed, and the floating gate 30 is covered with apserities, the source area 34b is not covered with oxide. A new thermal oxide 37 is then grown over floating gate 30, source area 34b and the whole array, in a mixture of oxygen and steam at 800 degree C. to a thickness of about 150 Angstroms. Another layer of TEOS (tetraethylorthosilane) based LPCVD oxide layer 38 is deposited to a thickness of about 300 Angstrom over thermal oxide 37, as shown in FIG. 10. This combination of thermal oxide and deposited oxide dielectric was shown to increase the oxide breakdown voltage and reduce electron trapping in the oxide, which is advantageous in EEPROM memory chips. Although, a combination of thermal oxide and deposited oxide was chosen in this embodiment, thermal oxide alone or deposited oxide alone will be sufficient to function as the interpoly dielectric.
After oxide layer 38 was deposited, its top surface topography will follow the shape of the textured top surface of the floating gate 30, however in a much more moderate undulations due to the oxide deposition process.
The thickness of the oxides on poly-1 layer 30 is 450 Angstrom, so is the thickness of the oxides on top of source area 34b. The thickness of the oxide on the bit-line regions 28 is about 1500 Angstroms. Due to the thermal cycles used in this fabrication process, the depth of the bit-line n+ regions 28a and 28b into the substrate will increase, but will remain small in relation to the transistors channel since the depth of trench 24 is subtracted from the depth of n+ regions 28.
At this stage a second polysilicon layer 39, illustrated in FIG. 10 is deposited on oxide layer 38 by LPCVD at 650 degree C. to a thickness of about 4000 Angstrom and then doped with phosphorous by passing POCL3 through a chamber at 950 degree C. for about 15 minutes.
The bottom side of the polysilicon layer 39, also called poly-2, will take the shape of the mild undulations on the top surface of LPCVD oxide layer 38, such that a convex asperity on top of poly-1 layer 30 will face a concave layer of polysilicon at the bottom side of poly-2 layer 39.
As is well known in the art the tunneling threshold voltage of electrons tunneling through oxide dielectric from convex polysilicon to concave polysilicon, also called forward tunneling threshold voltage VXF, is lower then the reverse tunneling threshold voltage VXR. The tunneling voltage of electrons tunneling through oxide dielectric from concave polysilicon to a convex polysilicon, also called reverse tunneling threshold voltage VXR is higher then the forward tunneling threshold voltage VXF.
This asymmetry of tunneling between two polysilicon layers is applied in the operation of the cell. Where reverse tunneling from poly-2 layer 39 to poly-1 floating gate layer 30 is used for programming and forward tunneling from poly-1 floating gate layer 30 to poly-2 layer 39 is used for erasure.
FIG. 11A and FIG. 11B illustrate sectional cuts along lines 11A and 11B of FIG. 10 respectively, in parallel to the bit-line axis. The resist layer 40 defines the word-lines 14 of FIG.-1. The structure of FIG. 11A and FIG. 11B is etched to define the word-line and the floating-gate. The etch process etches through polysilicon layer 39, the interpoly LPCVD oxide layer 38, inter-poly thermal oxide layer 37 and polysilicon layer 30. The etch does not pass through oxide layers 38 and 37 along section cut 11B, or oxide layer 29a along section cut 11A.
FIG. 12A and FIG. 12B illustrate the resultant structure of FIG. 11A and FIG. 11B after the etching to form the word lines 14 of FIG. 1.
FIG. 13 illustrates a sectional view similar to that shown in FIG. 10 after the addition of subsequent layers. An LPCVD TEOS based pad oxide layer 41 is deposited and is covered with a layer 42 of phosphorous-doped field oxide. Metal layers 43, for example of aluminum are then formed and patterned to form the column bit-lines. Each metal bit-line connects to a separate n+ bit-line 28 every several word-lines, through a contact opening in the field oxide. This is done in order to shunt the n+ higher resistance in order to prevent an undesired voltage drop between a selected cell and ground or the path between the selected cell and the sense-amplifier.
The metal lines of layer 43 are then covered with protective oxide coating 44 formed of 4% phosphorous-doped silicon dioxide.
FIG. 14 and FIG. 15 illustrate sectional views taken generally along the section lines 14-14' and 15-15' of FIG. 1. FIG. 14 and FIG. 15 are similar to FIG. 12A and 12B, with the addition of the pad LPCVD TEOS based oxide layer 41 and the phosphorous-doped silicon oxide layer 42.
As will now be apparent, the present invention provides the following substantial advantages over previously developed split-gate transistors containing a floating gate.
1) Unlike prior art devices the "electrical channel width" of the transistor is not reduced from the "drawn width" of the cell due to encroachment of the field oxide during isolation. Rather the channel width is defined by the word-line's polysilicon width and the trench 34, which is also the distance between n+ regions 28a and 28b. This provides higher cell current per drawn trnsistor width.
2) The absence of the "end-cap" of the floating-gate over the field oxide, reduces the spacing between word lines, thus significantly increases the density of memory arrays.
3) The alignment and fabrication process reduce the minimum split-gate transistor size, such that the drawn channel length between source and drain diffusion is the minimum critical dimension of the photolithography equipment used in manufacturing. And is not limited, as is the case in prior art, by the fact that two polysilicon layers, which are isolated from each other lay next to each other on the same channel, thus dictate the channel length.
4) Reduced punchthrough of the channel due to shalower n+ junctions in the bit-line areas. For example n+ junction depth for EEPROM embodiment, not using hot-electrons programming, is 0.15 micrometers, and 0.2 micrometers for UVEPROM embodiment. These values are lower then junctions needed for prior art split-gate devices.
5) Junction breakdown voltage is higher due to shalower bit-line n+ junctions.
6) In EEPROM embodiments using polysilicon to polysilicon electron tunneling for programming and erasure, there is no current flowing through the bit-line diffusions. And since the largest amount of current through the bit-lines of about 200 uA flows during the read operation, and is relatively low, the voltage drop across the n+ diffusion bit-line resistance will be small. Thus the width of the bit-line width can be narrow which further reduces the cell size and increases array density.
7) The transistor's EEPROM embodiment, which is not using hot electron programming or thin tunneling oxide, may be used in logic circuits as a regular NMOS transistor. This is because it does not suffer from the "soft-write" phenomenon typical to hot electron programmed transistors.
8) In the EEPROM transistor using poly-to-poly electron tunneling for programming and erasure, materials other then silicon may be used to fabricate this Field Effect Transistors. For example the substrate layers 25, 26, 27 may be of GaAs or Germanium, thereby increasing the transistor current by about threefold. This improves read access time in memory chips, and reduces delay in programmable-logic chips.
Preferred embodiments of the invention have now been described. Various substitutions and alterations to these embodiments will be apparent to persons of skill in the art apprised by the teaching of this patent. It is therefore not intended that the invention be limited to the described embodiments, but that invention be defined by the appended claims.
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A process for the fabrication of an EEPROM structure requiring only two poly layers that utilize hot electrons from the substrate for programming and poly-to-poly electron tunneling for erasure. The structure is advantageously utilized in an Ultra Violate Light Erasable PROM.
The process results in a structure that allows programming and erasure by electron tunneling only.
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BACKGROUND OF THE INVENTION
The subject of this invention is a surgical reamer fitted with a device allowing it to be fixed to a tool holder so that it can be driven in rotation and with at least one cutting edge made up of the edge of a plate containing the reamer's rotary axis.
A reamer of this sort is known under U.S. Pat. Nos. 3,633,583 and 5,290,315. On these reamers, the cutting edge is formed on a half-disk inserted into a diametric split made in a monolithic head which is noticeably hemispherical. The disk is held in the head by a screw and the head has gashes, like a drill bit, for the formation of shavings. In operation, there is an increased risk of these reamers becoming off centre due to the lack of homogeneity of the osseous matter.
From document EP 0 947 170, the content of which is incorporated herein by reference, a surgical reamer is shown, particularly intended for the processing of the cotyloid cavity when replacing the hip joint with a total prosthesis, in the shape of a revolving hollow body, in particular a hemispherical cap stretching from one side of the rotary axis and whose edge, over half of its circumference, constitutes the cutting edge. The surface of the cap itself may be fitted with teeth as with reamers of the rasp type which are commonly seen in previous practice, as described, for instance, in patents FR 2 281 025, EP 0 704 121 and 0 782 890, the content of which is incorporated herein by reference. However, it is very difficult to form an exact hemisphere using the usual processes, such as stamping.
What is needed is a surgical reamer allowing the centring to be maintained whilst in operation, using simple means. In addition, what is needed is a reamer that has a small insertion profile, compared to its swept cutting area.
SUMMARY OF THE INVENTION
A surgical reamer according to the invention has a cutting structure rotatable about a longitudinal axis. The structure has a static profile area upon insertion of the reamer into the bone socket and a dynamic profile area generated upon rotation, both profile areas lying transverse to the axis. The static profile area is substantially smaller than the dynamic profile area. The reamer includes centrally located holes ( 18 ), allowing it to be fixed to a tool holder. The invention therefore has a low insertion profile permitting entry into an incision of a relatively small size.
The reamer form may be spherical, conical or of some other shape. At least one cutting edge can be fitted with teeth.
According to the preferred mode of production for the invention, the reamer is made up of two plates which are split down the middle according to their axis of symmetry and housed at right angles to and inside one another. This is particularly simple to manufacture and also stands out due to its good rigidity and by how easy it is to clean.
The plates constitute the cutting structure. The plates are angularly arranged around the rotary axis in such a way as to form three edges including at least one which is a cutting edge. The distribution of at least three edges around the rotary axis ensures that centring is maintained during milling. If only one of the edges is a cutting edge, the other edges are used only for guiding, that is to say for maintaining the centring.
The disk, whose split leads out onto the top of the reamer, can usefully be cut so as to release the profile of the other disk at the top and thus allow a cut in the centre when milling.
The plates have holes used for fixing the reamer onto a tool holder or an adapter with a head fitted with frontal slots extending radially in relation to the support axis and oriented in such a way as to allow them to house the reamer plates. The devices used to hold the reamer in the slots are usefully made up of balls which engage in the holes on the reamer's plates and a ball locking device keeping the balls engaged in the holes in the plates.
BRIEF DESCRIPTION OF THE DRAWINGS
As an example, the appended drawing shows a mode for producing the invention.
FIG. 1 is a perspective view of the reamer.
FIGS 2 a – 2 c shows three examples of teeth formed on the disks.
FIGS. 3 a – 3 i show examples of disk cutting profiles.
FIG. 4 shows the same reamer mounted on an adapter.
FIG. 5 shows the adapter in the reamer release position.
FIG. 6 is a side view of the adapter.
FIG. 7 is an axial view of the adapter.
FIG. 8 is an exploded view of the adapter.
FIGS 9 a – 9 b show a cup for recovering the shavings before being mounted on the reamer.
FIG. 10 shows the same cup mounted on the reamer.
FIGS. 11 a – 11 b show variants for point or centering stock production.
FIG. 12 shows an embodiment in which the plates are not equally spaced about the rotational axis.
FIG. 13 shows the static profile area vs. the dynamic profile area of the invention.
FIG. 14 shows the static profile area vs. the dynamic profile area of a prior art product.
DETAILED DESCRIPTION OF THE INVENTION
The reamer shown in FIG. 1 is made up of two disks or plates 1 and 2 perpendicularly assembled. The plates 1 and 2 make up a cutting structure 50 . The cutting structure 50 is rotatable about a longitudinal axis X—X when mounted to a holder 6 .
For this purpose, the plates are split down the middle, that is to say according to a radius leading into a central circular cut 3 and they are housed in one another by means of these slots and laser welded so as to give a spherical case of which edges 4 and 5 make up meridians. Edges 4 and 5 present sharp edges forming cutting edges.
In the example shown, disk 1 has a split which leads to the top 30 of the reamer and is cut so that the sides of its split 31 diverge from one another on the plane of the other disk 2 , on both sides of the reamer's rotary axis X—X. The effect of this is to release the edges of the disk 2 at the top 30 and to thus allow a centre cut when milling.
At least one of the edges 4 , 5 of the plates can be fitted with cutting teeth. Examples of teeth shapes are shown in FIG. 2 , either teeth in a U shape (a), an “N” shape (b) or sloping slot teeth (c). The four edges of the reamer should preferably be fitted with teeth and these teeth are offset, respectively alternated, from one disk to the other or from one half-disk to the next, in relation to the trajectory of these teeth, so as to obtain a full sweep, without grooves, when milling a spherical cavity.
The cutting edges 4 and 5 may show various cutting profiles examples of which are shown in FIG. 3
a) half-moon profile on the topside, b) elliptical profile generating a positive cut, c) half-moon profile on the cutting side of the plates with a neutral cutting angle d) half-moon profile on the cutting side of the plates with a positive cutting angle e) diagonal profile generating a positive cutting angle, f) neutral profile, g) half-moon profile on the topside with two relief angles per disk, h) half-moon profile on both sides of the plates, i) tenon profile which can synthesise profiles a} to h}.
A reamer of this sort cannot be fixed directly onto a tool holder as described in the applicant's patent EP 0 704 191 (U.S. Pat. No. 5,658,290), the content of which is incorporated by reference herein, which has a head intended to house a cross held by a bayonet fixture. In order to be able to use the same tool holder for reamers fitted with a fixing cross, the new reamer is fixed onto an adapter 6 shown in FIGS. 4 to 8 . This adapter could obviously constitute a full tool holder.
The holder 6 has a cylindrical body 7 fitted, at one end, with a head 8 designed to house the reamer and, at the other end, with a fixing cross made up of four cylindrical branches 9 forced radially through the body 7 . The head 8 , generally cylindrical in shape, is split diametrically so as to have four slots 10 which are at right angles to one another, whose width corresponds to the thickness of plates 1 and 2 . These slots 10 are limited on one side by a relatively thin wall 11 and, on the other side, by a rather thicker wall 12 . The walls 12 are pierced by a circular hole 13 , which is cylindrical over most of the walls. The balls 14 , whose diameter is greater than the thickness of the walls 12 are held in these holes. These balls 14 can also be moved into the holes 13 50 as to release the slots 10 or not.
A locking ring 15 , with four pins 16 is mounted, sliding, onto the body 7 stretching out in parallel to the axis of the ring. These pins 16 are engaged in the head 8 , more precisely in the spaces left free by the walls 11 and 12 . Each of these pins 16 has one flat side 17 which at least approximately slides onto the side of a wall 12 opposite the corresponding split 10 , so as to keep the corresponding ball engaged in the split 10 , as shown in FIG. 7 . If the reamer is engaged in the slots 10 , the balls 14 are then engaged in the holes 18 on plates 1 and 2 so that the reamer is held onto the head 8 .
The ring 15 is held in this locking position by a spring 19 which rests on a supporting ring 20 which is mounted on the body 7 of the adapter, as shown in FIG. 4 . In order to release the reamer all that must be done is pull out the locking ring 15 by constricting the spring 19 , as shown in FIG. 5 . The reamer can then be removed from the head 8 by pushing back the balls 14 . The same method is used to fix the reamer onto the adapter. This type of locking/unlocking mode is described in the Swiss patent application No 409/00, the content of which is incorporated by reference herein. To lock the balls 14 into the reamer, all you have to do is release the ring 15 .
In order to allow the adapter to be cleaned properly, the supporting ring 20 is mounted in such a way that it can be pulled out backwards as far as the cylindrical branches 9 , which allows you to also bring back the locking ring 15 and to release the spring on the ring 15 . For this purpose, the supporting ring 20 is fitted with a radial pin directed internally (not shown in the drawing) and the body 7 of the adapter has a longitudinal groove 21 into which this pin can slide. The upper end of the groove 21 leads to a notch 22 into which the pin on the ring 20 can be bayonet fixed by means of a slight rotation.
The reamer can usefully be fitted with a device allowing the shavings to be recovered. The plates offer a particularly simple and effective solution shown in FIGS. 9 a , 9 b and 10 .
The recovery devices are made up of a cup 32 in the shape of a hemispherical dome supported by a ring 33 . The diameter of the cup 32 is slightly less than the diameter of the plates 1 and 2 and this cup has four splits 34 stretching according to the meridian levels at right angles to one another and over a part of the height of the ring 33 , over a part 35 of the latter which has the same diameter as the cup 32 . The width of the splits 34 is noticeably greater than the thickness of the plates 1 and 2 and these splits are asymmetrical in relation to the corresponding meridian plane, in such a way that when the cup 32 is mounted on the reamer ( FIG. 10 ) the plates 1 and 2 cross the splits 34 leaving a split 34 ′ behind the plates in relation to the reamer's direction of rotation, so as to allow the shavings to penetrate into the cup 32 through these splits 34 ′. It will be noted that the reamer plates shown in figures 9 a and 9 b and 10 are fitted with U-shaped teeth 50 a , 50 a ′, 50 b , and 50 b ′ which project over the surface of the cup 32 .
FIG. 11 illustrates a variation in which the two plates 1 and 2 are totally flat and form a cross at the end of the reamer. The reamer is fitted with a drill bit 36 fixed axially onto this cross. For this purpose, the bit 36 has two slots running crossways by means of which it is fitted onto the plates. The bit is laser welded onto the plates 1 and 2 .
Instead of a bit, a simple centre point or a trocar point 37 could be fitted.
A drill bit or a point could be fixed in the same way onto a reamer made up of three, five or more plates.
FIG. 12 depicts an reamer 38 in which the plates 40 and 42 are spaced about the rotational axis so as to result in unequal spaces 44 between plates. The spaces 44 encompassed by angle β are smaller than the spaces encompassed by angle β, thus resulting in X and Y dimensions which are different.
FIG. 13 illustrates a cutting structure 50 , made up of the two plates 1 and 2 . When viewed statically and axially, the cutting structure 50 presents a two dimensional static profile area 52 in the form of a cross. The square 53 inscribed on the corners of this cross represents the minimum size of an incision which will allow passage of the reamer. The square 53 is therefore the effective profile seen by an incision upon insertion of the reamer into the bone socket and covers approximately 80% of the area of the circular profile area 54 . When this static profile 52 is rotated during cutting, it sweeps out the circular profile area 54 inscribed by the phantom line circle 56 .
FIG. 14 shows a conventional reamer 60 , in which the static profile area 62 is essentially a circle with small protrusions 64 constituted of cutting divots. When rotated during cutting, the static profile area 62 sweeps out a dynamic profile area 66 , inscribed by the phantom line 70 , only insubstantially larger.
Thus, an advantage of having a substantially smaller static profile area 52 than dynamic profile area 54 is that the size of the incision required in order to receive the reamer is much smaller than that required for conventional reamers.
The invention is not limited to the modes of production described. Instead of the two fitted plates, the reamer could be made up of plates fixed radially on an axis, by means of welding, for instance. There do not have to be exactly four plates, but there must be at least one.
Whether these are plates fitted as shown or plates welded onto an axis, these plates could be of a different shape, for example a shape limited by a truncated or other form of case.
Although illustrative embodiments of the invention have been shown and described, a wide range of modification, change and substitution is contemplated in the foregoing disclosure and in some instances, some features of the present invention may be employed without a corresponding use of the other features. Accordingly, it is appropriate that the appended claims be construed broadly and in a manner consistent with the scope of the invention.
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A low insertion profile surgical reamer for cutting a bone socket comprises a cutting structure. The cutting structure is rotatable about a longitudinal axis. The structure has a static profile area upon insertion of the reamer into the bone socket and a dynamic profile area generated upon rotation, both profile areas lying transverse to the axis. The static profile area is substantially smaller than the dynamic profile area. The reamer includes centrally located holes, allowing it to be fixed to a tool holder.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention concerns a pump connector device for inflating a pneumatic tire. It concerns more particularly an improvement enabling use of the pump for tires from different sources incorporating valves of different types.
2. Description of the Prior Art
In the field of vehicles with two wheels, for example, it is necessary to re-inflate the tires periodically. This can be done using a manual pump or a low-power compressor.
In all cases the problem arises of connecting the source of compressed air to the valve of the tire. Depending on the source of the tire, the valve may be of one type or another. In the field of tires of two-wheel vehicles, for example, the valves most commonly used are essentially of two types known by their trade names "SCHRADER" and "PRESTA". One prior art pump has two different fixed connectors, each connector including an elastomer material sleeve adapted to surround the body of the valve with a seal between them.
However, in particular in the case of a hand pump and where the connector device is rigidly fastened to the pump body, the connector used is difficult to attach to the valve with an effective seal. Moreover, in the prior art system, the connector that is not used is neutralized by an internal closure system that is actuated pneumatically on the first stroke of the pump. This system is of high unit cost and is not totally reliable after some period of use.
A first aim of the invention is to propose a system that is simpler, more reliable and less costly for selecting the appropriate connector.
Another aim of the invention is to propose a further improved system in which the connector selected can be attached to the valve in a very firm and sealed manner.
SUMMARY OF THE INVENTION
Thus, in a first aspect, the invention concerns a pump connector device for inflating a pneumatic tire comprising an air ejector channel adapted to be connected to said pump and a mobile member containing at least two different connectors and movable in a housing between at least two predetermined positions in which one of said connectors communicates with a downstream end of said passage in a position in which it can be connected to a pneumatic tire valve.
The mobile member may be a slider moving along a straight path in a housing. In a different embodiment, the mobile member may have a rotary part inside a cavity into which said ejector passage opens.
In accordance with another advantageous feature of the invention, each connector includes an elastically deformable material sleeve adapted to be pressed against said valve and further comprising a locking mechanism cooperating with said mobile member to compress axially at least said sleeve of said connector in said position adapted to be connected to a valve, said axial compression of said connector causing it to be deformed radially inwards to grip and to be sealed to said valve.
The invention will be better understood and its other advantages will emerge more clearly from the following description of various embodiments of a pump fitted with a connector device of the invention, given by way of example only and with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an elevation view of a connector device of the invention.
FIG. 2 is a view analogous to that of FIG. 1 showing the same device in longitudinal section.
FIG. 3 is a view analogous to FIG. 2 showing the components of the device when the locking lever is actuated.
FIG. 4 is an elevation view of the end of a pump equipped with a connector device constituting a different embodiment of the invention.
FIG. 5 is a view analogous to FIG. 4 showing the same device in longitudinal section.
FIG. 6 is a view similar to FIG. 5 showing the components of the device when the locking lever is actuated.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring more particularly to FIGS. 1 to 3, a pump connector device 11 for inflating a tire of a two-wheel vehicle is shown connected by a screwthreaded connector 12 to the end of a flexible hose 13 in turn connected to a pump that cannot be seen in the drawing. The device includes a body 14 within which is defined an air ejector passage 16. The latter is formed by two perpendicular bores, a longitudinal bore 16a opening into the screwthreaded bore 17 into which the connector 12 is screwed and a transverse bore 16b. The exit orifice 19 of the passage, at the same end as the transverse bore, is defined on a first surface 20 of the body 14. An opposite and parallel second surface 21 of this body constitutes a bearing surface for a cam 22 at the end of a lever 23. The body 14 is covered by a cap 25 defining with said first surface 20 an elongate housing 27 having on a face 28 parallel to said first surface 20 an orifice 30 for insertion of the valve. A mobile member 32 is movable in the housing 27 between at least two predetermined positions. This mobile member, here constituting a sort of slider of generally rectangular parallelepiped shape, contains at least two different connectors 33, 34.
Of course, the number of predetermined positions is equal to the number of different connectors. For each predetermined position one of the connectors is axially inserted between the exit orifice 19 of the passage and the orifice 30 into which the valve is inserted.
An annular seal 36 is provided around the opening of the passage; it comes into contact with one face of the mobile member forming the slider. The two connectors are parallel to each other within the slider. To be more precise, the latter is constituted by the assembly of two parts 37, 38 nesting one inside the other with two elastomer material sleeves 39, 40 between them. Thus the part 37 in contact with said first surface 20 of the body 14 includes a first cylindrical tubular passage 44 and a second passage 42 parallel to the first and containing an axial insert 41. The part 38 in contact with the interior wall of the cap 25 includes a first cylindrical tubular passage 43 having an internal shoulder and axially aligned with the first passage 44 and a second cylindrical tubular passage 45 having an internal shoulder and axially aligned with the second passage 42. The elastically deformable material sleeve 39, having an internal shoulder and an external shoulder, is disposed between said first passages of the parts 37 and 38. The other cylindrical tubular elastically deformable material sleeve 40, of the same kind, having an internal shoulder, is disposed between said second passages of the parts 37 and 38. In fact, the arrangement just described reconstitutes within a slider structure two different, standardized connectors 33 and 34 well known in themselves. The two connectors are parallel to each other and the mobile member 32 in the form of a slider can move along a straight path in the housing 27 between the two orifices. Each connector 33, 34 is therefore ready for use when the slider is in a corresponding predetermined position in its housing.
In this position the elastically deformable material sleeve 39 or 40 is pressed against the body of the valve that is inserted into the orifice, providing a seal all around it.
To improve this connection, the device further comprises a locking mechanism cooperating with the mobile member 32 to compress in the axial direction at least the sleeve of the connector 33 or 34 in position for connection to said valve. This axial compression of the connector causes it to be deformed radially inwards, so that said valve can be firmly gripped to make a perfectly sealed connection. To achieve this, the two parts 37, 38 are not in abutment when at rest, but can be moved relative to each other by a force tending to compress the sleeves 39, 40 in the axial direction. Actuation of the locking mechanism also compresses the seal 36, providing a perfect seal at the interface between the body 14 and the slider.
The locking mechanism includes the lever 23 mentioned above, carrying the cam 22, and this assembly is adapted to cause relative movement between at least a part of the mobile member 32 and the body 14 containing the air ejector passage. To this end the cap 25 is slidable along the body 14 and the lever 23 is articulated to said cap 25 by a pin 49.
The cap also includes a straight slot 50 parallel to the direction of movement of the mobile member 32 and the latter has a lateral operating finger 52 passing through said slot. The slider can be maneuvered by means of this finger when the lever 23 occupies the position shown in FIG. 2. In this way the appropriate connector may be selected.
When the lever occupies the position shown in FIG. 3, the mobile member 32 forming the slider is compressed in its housing because of the movement of the cap 25 relative to the body 14. The two parts constituting the slider move towards each other, which deforms the elastically deformable sleeves 39, 40, as shown in FIG. 3. In particular, the deformation of the sleeve 40 of the connector 34 in the "use" position causes it to firmly grip and seal a valve (not shown) inserted in the orifice 30.
FIGS. 4 to 6 show a different embodiment of a connector device 60 mounted directly at the end of a pump cylinder 61. The pump outlet is extended by a body 62 containing the air ejector passage 63 in which a ball check valve 64 is fitted. The travel of the ball is limited by an abutment 65 extending axially in said passage.
In this embodiment, the mobile member 68 previously mentioned has a rotary part inside a cavity 67 into which the ejector passage opens. Note that the outlet orifice 69 of the air ejector passage is coaxial with the orifice 70 for inserting the valve. The rotary part includes a transverse conduit 72 incorporating two different connectors 73, 74 analogous to those shown in FIGS. 2 and 3. These two connectors are axially aligned and face in opposite directions. They therefore extend globally between the outlet orifice 69 of the passage and the orifice 70 for inserting the valve. The conduit has a central part 75 having a cylindrical tubular passage on one side and a passage provided with an axial insert on the other side and two elastically deformable material sleeves 77, 78 analogous to the sleeves of the previous embodiment and extending axially on either side of the part 75.
The conduit 72 defined above constitutes a guide for two globally semi-cylindrical members 80, 81 sliding on the outside of the transverse conduit and urged apart by springs 84 between them. The semi-cylindrical exterior surface of each member 80, 81 includes ribs 86 or some other equivalent configuration.
The combination of the conduit 72 and the two semi-cylindrical members 80, 81 is mounted between two clamping parts adapted to be moved towards each other by a lever 88 carrying a cam in contact with the body 62, compressing the assembly in the axial direction defined by the two orifices 69, 70.
To be more precise, one of the clamping members is the body 62 housing the air ejector passage 63 and having a concave surface 90 housing part of the assembly comprising the conduit 72 and the two semi-cylindrical members 80, 81. The other clamping part 92 has two arms 93 sliding in two corresponding grooves of the body 62. The lever 88 is articulated by a pin 95 between the two ends of these arms. The orifice 70 for insertion of the valve is in the second clamping part 92 which also has a concave surface 97 surrounding a part of said assembly comprising the conduit and the two semi-cylindrical members.
In the position shown in FIG. 5 the aforementioned assembly 72, 80, 81 may be rotated in its housing defined between the two clamping parts 62, 92 to move one or other of the two connectors 73 or 74 into the service position. When a connector is in the service position, the elastically deformable material sleeve of the other connector is in a position that provides a seal between the orifice 69 of the passage 63 and said conduit 72. Operating the lever moves the two clamping parts towards each other and brings about the required deformation of the two elastically deformable material sleeves 77, 78.
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A pump connector device for inflating different pneumatic tires including different type valves includes a mobile member containing at least two different connectors. The mobile member is movable in a housing so that one or other of the connectors can be used.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates to cooling of computing environments and more particularly to water cooling of large computing systems.
[0003] 2. Description of Background
[0004] The industry trend has been to continuously increase the number of electronic components inside computing systems. A computing system can include a simple personal computer, a network of simple computers, or one or even a network of large computers that include one or more central electronic systems (CEC). While increasing the components inside a simple computing system does create some challenges, however, such an increase can create many problems in computing systems that include one or more large computers. In such instances many seemingly isolated issues affect one another, especially when packaged together in a single assembly or networked or housed to other systems that are stored in close proximity. In addition, the increased density of these systems give to the increase in their energy consumption and, consequently, the rise in their internal temperatures due to the collective heat. Consequently, the issue of heat dissipation has become a priority in the design of these computers.
[0005] In the past air cooling concepts has been used extensively in the design of these computers. However, as the advancements in heat sink and fan design is beginning to outpace air cooling capabilities, further alternatives are becoming more attractive. In recent years, liquid and especially water cooling have become a more attractive and viable option. The advantages of fluid/liquid and specifically water cooling, are many including fluid/liquid/water's higher specific heat capacity, density and thermal conductivity. In addition, such cooling methods will allow the heat to be trasported away from the source to secondary cooling surfaces that allow for larger and more optimally designed cooling techniques when feasible. Unfortunately, running liquids and especially water through a device that is largely powered by electricity can be risky and dangerous. In order to reduce a risk of leakage it is optimal, in these situations, to use as few fittings and connectors as possible in such cases with respect to piping that provides the coolant to the system. Unfortunately, this is not always feasible and therefore, there is a need to provide safety features when there is a need to provide piping especially those with many fittings and connectors to reduce risk of leakage. In particlular there is a need for a method and apparatus that can control liquid/water sprays that might occur when quick connects (hereinafter QC's) fittings are used to help adapt pipings of different sizes or shapes to one another, or to regulate fluid flow during the use, mating or unmating of them within a computing system.
SUMMARY OF THE INVENTION
[0006] The shortcomings of the prior art are overcome and additional advantages are provided through the provision of a method and incorporated assembly for providing an insulating housing and a protective sleeve for quick connect fittings and couplings of a computer system environment. In one embodiment, the insulative housing has a hollow center to be placed around the couplings and further comprises an insulative sleeve having a plurality of complementary parts that fit together around the coupling as a singular unit and a fastener to open and close the sleeve such that the coupling is at least partially exposed. In an alternate embodiment, a protective sleeve with a hollow center is provided that once disposed around the quick connect fittings, will protect against leakage of liquids flowing into quick connect fittings during mating and unmating of them. The sleeve comprises an actuation collar area that extends over unmated portion of the quick connect fitting and a a flare area disposed over the actuation collar to provide an additional gripping area for actuating the quick connect fitting.
[0007] 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.
DESCRIPTION OF THE DRAWINGS
[0008] 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:
[0009] FIG. 1 is an illustration of one embodiment of the present invention using a male and female type quick connect fitting;
[0010] FIG. 2 provides an illustration of a protective sleeve as per embodiment of the present invention;
[0011] FIG. 3 provides an illustration of fastening components provided as part of the shielding housing of the embodiment of FIG. 1 ;
[0012] FIG. 4 provides yet another alternative embodiment for the present invention illustrating an insulative housing;
[0013] FIG. 5 is an illustration of the insulative sleeve provided as part of the insulative housing of the embodiment of FIG. 4 ;
[0014] FIG. 6 provides an illustration of fastening components provided as part of the insulative housing of the embodiment of FIG. 4 ; and
[0015] FIG. 7 provides an illustration of different elements of the fastening component of FIG. 6 after they have been assembled.
DESCRIPTION OF THE INVENTION
[0016] FIG. 1 is an illustration of one embodiment of the present invention. In the example shown in FIG. 1 , a male and female type quick connect fitting is shown. For ease of understanding, the male fitting is referenced as 110 while the female fitting is referenced as 120 . In this particular example, the male and female fittings are already engaged as shown. It should be noted that once engaged, the two portions of the quick connect fittings 110 and 120 are surrounded by an actuation sleeve that provides somewhat of a protection to fluid leakage. The actuation sleeve is shown in both FIGS. 1 and 2 and referenced by numerals 130 .
[0017] Although, not shown in the figures, each male and female fitting will also be connected to piping on the side opposing where they are engaged with one another. The coolant fluids and liquids like water will be flowing through the piping connected to the female fitting into the male and female fitting and then into the male fitting as can be appreciated when source of coolant is provided in the computer environment to provide cooling to the intended source.
[0018] As discussed earlier, whenever fluid/liquid coolants such as water are involved and there is a mating connection such as the fitting shown by way of example in FIG. 1 , there is always a possibility that the connection is not completely sealed. Even the use of sealants may be affected due when exposed to long term stress and temperature changes. In addition, there are times, when the mating and unmating of the fittings as shown has to be conducted while the fluid or liquid is still flowing in the pipeline. Having to shut the coolant source may pose additional challenges during installation and servicing of the computer.
[0019] In FIG. 1 , as per one embodiment of the present invention, illustrates a protective sleeve (with a hollow center) that is provided around the area where the fittings are to be connected/mated to one another. The protective sleeve is referenced by numerals 152 in the figure as shown.
[0020] This protective sleeve controls any leakage or generally any sprays from getting on the sensitive electronic components in the surrounding areas. The first is a protective sleeve is comprised of an actuation collar area, referenced by numerals 152 , in the figure. The second is a flared area, referenced by numerals 155 , in the figure. In a preferred embodiment, the flared area actually provides an additional grip area to actuate the quick connect as can be seen in the illustration of FIG. 1 . It should be noted also that while in this particular example, it may be preferred to have the flared area 155 around the female fitting of the quick connect, this is not a restriction and it is possible in alternate embodiments to have the flared area 155 in other areas surrounding the quick connect fittings.
[0021] FIG. 2 provides an illustration of the protective sleeve 150 as per embodiment of the present invention when the quick connect fittings are disengaged. The same male 110 and female 120 fittings are used again in the example illustrated in FIG. 2 for ease of understanding and reference. As discussed earlier, while it is preferable in this particular example to have the protective sleeve remaining around the female fitting 120 of the quick connect once the two fittings are disengaged (as shown), this can easily be altered selectively, in other embodiments as desired.
[0022] As can be appreciated from looking at this figure, once the quick connect male 110 and female 120 fittings are unmated, the protective sleeve acts as a shield and will control any liquids/fluids such as water that might spray to the adjacent electronic components. This is due to the fact that the collar area 152 extends well beyond the female portion 120 (in this example).
[0023] The illustration of provided by FIGS. 1 and 2 , shows a preferred embodiment of the present invention where at least the collar area 152 is made from a clear material, more particularly a clear plastic.
[0024] In addition, while the illustrations as provided in FIGS. 1 and 2 provide for a design of the sleeve that seems to be unitary, this is not always the case. While a unitary design that is made from a sufficiently flexible material that can be disposed in place securely around one part of the quick connect fittings is plausible, the illustration of FIG. 3 provides a different and alternative design for the present invention.
[0025] As stated, FIG. 3 provides an alternate embodiment of the present invention where the protective sleeve, previously referenced as 150 in FIGS. 1 and 2 , is created from a plurality of pieces. In the embodiment shown, for ease of understanding, there are two sleeve pieces and these can be made from the same material and/or part if desired. In the illustration of FIG. 3 , numerals 350 are picked to reflect the differences between the two embodiments, although once the two pieces of FIG. 3 are engaged, they will appear as the same unitary unit as was illustrated and discussed in the previous figures.
[0026] In the embodiment illustrated in FIG. 3 , the two pieces of sleeve are substantially the same but have complementary latching parts. For this reason, the two pieces are identified both as 300 . The latching parts 370 and 380 can be either formed and molded from the same material, hence making the two parts of sleeve 300 , complementary or they can be an added features that gets added to the sleeve counterparts 300 . In either case the two pieces 370 and 380 will fasten to one another securely to render the sleeve a unitary unit as discussed. As known to those skilled in the art, a number of fastener such as latching and mating, can be used in alternate embodiments to connect the sleeve pieces 300 securely to one another. In the example of FIG. 3 , in one embodiment, the fasteners 370 have protrusions, 371 , that are placed inside perforations, 381 , in their complementary counterpart 380 . The fasteners 370 further comprise a lip, 372 , extending from the protrusions once disposed in the perforations of 380 that extend out to render the connection even more secure.
[0027] In another embodiment, the fastener 370 can have perforations 375 , while the fastener 380 has protrusions 381 . As used in this example, a variety of such means can be used in a single sleeve design as desired to ensure a very secure fit of the two complementary counterpart sleeves 300 .
[0028] As was the case previously, in FIG. 3 , the invention is designed taking into account that a quick connect with an actuation sleeve 130 is provided, here on the female coupling which is rather used in conventional fittings. This, however, is by way of example and other designs can be selectively used. FIG. 3 also provides a preferred embodiment where a clear plastic shield used and created around this actuation sleeve 130 using the two complementary pieces or parts 300 as discussed. It should be noted again that these pieces or parts snap together around the actuation sleeve 130 in this case and are retained. The fact that they can be placed around the piping (because of the two piece complementary design) before or during the mating of the fittings, will make this design very functional and easy to use during installation and servicing. The same an additional flared area, now referenced as 355 still provide an additional grip area to actuate the QC. As the QC's are mated and unmated the shield will control any water that might spray to adjacent electronic components.
[0029] FIG. 4 provides yet another alternative embodiment for the present invention illustrating an insulative housing 490 , comprised of an insulative sleeve 400 and fastener 430 . The housing has a hollow center 410 such that it can be disposed around a coupling or piping etc. of a computer or a computing environment. This design as provided in his embodiment, is to address another issue that has not been resolved by the prior art which will be presently discussed.
[0030] When quick connects (QC's) are used carrying substances, such as the fluid/liquid coolants discussed above certain problems arise when these substances having temperatures that are below dew point as they can cause condensation. Condensation may also form in other situations due to particular shipping or storage requirements of the computers. In either case, when condensation is a possibility, the QC's need to be insulated to prevent condensation from forming which will hurt the sensitive electronics that reside in the surrounding areas. The alternate embodiment of the present invention, as provided in FIGS. 4 through 7 , provides such a protection.
[0031] FIG. 4 provides an illustration of an insulative sleeve, as referenced by numerals 400 in the figure. The insulative sleeve 400 can be used on a variety of piping provided in a computing environment, such as for example, on an IBM modular refrigeration unit (MRU). In this example, the insulative sleeve 400 comprises of two, preferably molded parts, referenced by numerals 402 and 404 respectively. The two molded parts, 402 and 404 , will also be referenced as first sleeve component and second sleeve component 402 and 404 . These components are held together with a fastener 430 . The fastener is illustrated and referenced by numerals 430 in the figure. In a preferred embodiment, the fastener 430 is comprised of latches. In addition, in the exemplary design provided in FIGS. 4 through 7 , the two molded 402 and 404 parts are used to create a clamshell concept.
[0032] FIG. 5 provides the same insulative sleeve as discussed in conjunction with the embodiment of FIG. 4 , while the two parts 402 and 404 are not engaged with one another to provide a unitary unit. In this figure, it is easier to see the particular fastener used as well. As illustrated, in this embodiment, the fastener 430 , that was previously reflected as a unitary unit is also comprised of two parts. In this example, two fastener are provided on each side of the insulative sleeve (collectively referenced previously as 400 ). Each fastener, is further broken down into a plurality of components, in this case referenced as 433 , 435 , 437 and 439 . It is possible to utilize only one fastener with two or more components or use more than two fasteners with a single component or many components as can be appreciated by those skilled in the art. In this embodiment, however, the above mentioned components are used to create ease of understanding.
[0033] The parts 433 and 435 are complementary to one another as well as parts 437 and 439 . In this example fastening components 433 and 437 are both attached to what will be referenced because of the positioning of the figure as upper insulative sleeve component 402 . Similarly, fastening components 435 and 439 are attached to the lower insulative sleeve component 404 . While, fastening components 433 is attached like fastening component 437 to the upper insulative component 402 , and while fastening component 433 is complementary to that of 435 while component 437 is also complementary to 439 , fastening components 433 and 437 are intentionally chosen in this example not to have identical or even similar design. In other alternate embodiments, it is possible to provide similar designs for these components but in the present case, an example with dissimilar fastening components is chosen for ease of understanding. In fact, in this particular example, fastening components 435 and 437 both have protruding parts, reference by numerals 460 , that will be disposed in complementary receptacles, referenced as 461 , provided in components 433 and 439 to make the fastening possible.
[0034] The fastener and their components can also be either integral with the insulative sleeve or its components or be fabricated such that it can be disposed on the sleeve. This latter option as illustrated in FIGS. 6 and 7 is preferable because it allows the insulative sleeve components to be fabricated to be exactly identical if desired. In a preferred embodiment, the sleeve and its component, if any, will be molded out of plastic.
[0035] FIG. 6 illustrates how the fastening components themselves may comprise of elements that allow the fastening component to be disposed securely on the sleeve component. In the example shown in FIG. 6 , a rotated view of lower sleeve component 404 of the previous figure is replicated. As can be viewed, the lower sleeve component 404 has fastening component 439 disposed on one side. One the opposing side a disassembled view of what was fastening component 435 is shown.
[0036] As illustrated, the fastening component 435 , comprises of a first element 636 and a second element 638 . The first element 636 is simply disposed over an edge or an inner thickness of the sleeve component 404 . The first element is then engageable with the sleeve component. For example, in the illustration, an opening 671 is provided for this first element which will fit into the protrusion provided on the sleeve component 404 them t, and referenced by numeral 672 to engage them together. In this embodiment, it is important to note two design features. The first element 636 is a substantially flat and thin plane that can easily be disposed between the two sleeve components 404 and 402 without causing any gaps in their fit. In addition, the protrusion 671 , provided on the sleeve component 404 , in this embodiment is added as an additional securing feature to ensure a tighter fit between the sleeve components. The protrusion 672 will engage with an opening provided on the upper sleeve component 402 (not illustrated here) which will be substantially similar to the opening on the other side of the sleeve component, referenced by numerals 682 . The opening 682 , in turn will have a complementary protrusion on the upper sleeve component 402 that will fit securely into it which is similar to the protrusion indicated by numerals 472 on this portion of the sleeve. (Note that for the design of latter sleeve component using 682 , different enagagable means than the opening 671 will be used.)
[0037] A second element, referenced by numerals 638 , of the fastener 435 , will then fit in with the first element 636 to allow the latching function. This second element 638 can be secured to the first element 636 by means of a variety of complementary mating means such as the one provided and referenced by numerals 673 in the figure. Although, only one mating half (on the first element 636 ) is visible from the viewing angle provided in the figure, it can be appreciated, that a similar mating half is also disposed on the second element 638 . FIG. 7 provides an illustration of the two elements of the fastening component 435 once assembled.
[0038] Reviewing FIGS. 4 through 7 in conjunction with one another, the concept introduced by this preferred embodiment of the present invention, provide for a unitary insulative housing having two molded parts. One can be thought of as a basic insulation sleeve and the other is a latch. In this example, each part was used twice to create a clamshell effect. In this embodiment, the latch is inserted into the housing and a feature captivates it on the housing. The latch itself is comprised of two parts.
[0039] These housing is placed around a coupling or housing in parts. When the two (or more) parts of the housing are around the coupling, pushing forward on the one latch will lock the top and bottom housings together and then pushing the latch on the other side will lock that side of the housings together completing the attachment. At this point the coupling becomes encased in the housing that will provide thermally insulation for the coupling. The fastener (i.e. the latch) in this way can be opened and closed also to disengage the sleeve from its components partially and/or alternatively to at least partially expose the coupling.
[0040] 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.
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A method and associated apparatus for providing an insulating housing and a protective sleeve for quick connect fittings and couplings of a computer system environment. In one embodiment, the insulative housing has a hollow center to be placed around the couplings and further comprises an insulative sleeve having a plurality of complementary parts that fit together around the coupling as a singular unit and a fastener to open and close the sleeve such that the coupling is at least partially exposed. In an alternate embodiment, a protective sleeve with a hollow center is provided that once disposed around the quick connect fittings will protect against leakage of liquids flowing into quick connect fittings during mating and unmating of them. The sleeve comprises an actuation collar area that extends over unmated portion of the quick connect fitting and a flare area disposed over the actuation collar to provide an additional gripping area for actuating the quick connect fitting.
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BACKGROUND OF THE INVENTION
1. Field of Invention
The present invention relates to digital signal correlation techniques. In particular, the present invention relates to a method and apparatus for reducing the time required to acquire a Global Position System (“GPS”) signal.
2. Description of the Background Art
The process of measuring a global positioning system (GPS) signal begins with a procedure to search for the GPS signal in the presence of noise by attempting a series of correlations of the incoming signal against a known pseudo-random noise (PRN) code. The search process can be lengthy, as both the frequency of the signal and the time-of-arrival delay are unknown. To find the signal, receivers traditionally conduct a two dimensional search, checking each delay possibility at a variety of possible frequencies. To test for the presence of a signal at a particular frequency and delay, the receiver is tuned to the frequency, and the incoming signal is correlated with the known PRN code delayed by an amount corresponding to an estimated time of arrival. If no signal is detected, the search continues to the next delay possibility, and after all delay possibilities are checked, continues to the next frequency possibility. Each individual correlation is performed over one or more milliseconds in order to allow sufficient signal averaging to distinguish the signal from the noise. Because many thousands of frequency and delay possibilities are tested, the overall acquisition process can take tens of seconds. This search technique is repeated for the signal from each satellite needed to calculate a position and time result, e.g., five satellite signals.
In an effort to reduce the search time required to achieve a position location solution, various techniques have been explored that provide aiding information to the GPS receiver. The aiding information generally provides satellite ephemeris as well as an estimate of the receiver's position. The aiding information is generally coupled to the GPS receiver via a wireless network.
In U.S. Pat. No. 6,133,874, the GPS receiver acquires a GPS signal from a first GPS satellite using a conventional search technique as described above. A first pseudorange to the first GPS satellite is computed using this conventional technique. The GPS receiver then uses the aiding information (e.g., the satellite position, time of day and receiver approximate position) in combination with the first pseudorange to estimate the pseudorange to the next satellite. This combination of information enables the search range (time range) to be substantially reduced for each additional satellite signal. The signals from each satellite are sequentially processed in this manner until enough satellite signals are received to compute the position of the GPS receiver.
In U.S. Pat. No. 6,070,078, a GPS receiver obtains ephemeris information and a server calculates predicted PRN code shift positions based on a known location and the ephemeris data. A reduced functionality GPS receiver within a cellular telephone receives a time reference and then searches a limited number of PRN code shift positions for each of a plurality of GPS satellites based on the predicted PRN code shift positions. If a time reference is not transmitted to the reduced functionality GPS receiver, a PRN code shift position for a first satellite signal is measured by searching all possible PRN code shift positions. The measured PRN code shift position for the first satellite signal is then used to reduce the range of possible PRN code shift positions for remaining satellite signals.
The technique of U.S. Pat. No. 6,133,874 requires a pseudorange to be computed with respect to the first satellite. In a low signal to noise ratio environment, such a computation may require an excessive amount of time to achieve as many correlations as required to accurately compute the pseudorange. In addition, microprocessor time must be spent to compute the pseudorange. The technique of U.S. Pat. No 6,070,078 requires a time reference to reduce the search range for GPS signals. If a time reference is unavailable, the technique of U.S. Pat. No. 6,070,078 requires all delay possibilities for a first satellite signal to be searched. Again, in a low signal to noise ratio environment, such a computation may require an excessive amount of time to search all delay possibilities in order to accurately acquire the first satellite signal.
Therefore, there is a need in the art for a method and apparatus that reduces the amount of time required to acquire GPS satellite signals.
SUMMARY OF THE INVENTION
The invention provides a method and apparatus for reducing the time required to acquire GPS satellite signals. The method defines a window equal a portion of a predefined time period, correlates the GPS signal across the window, and identifies whether a correlation peak results from the correlating. In one embodiment, the predefined time period is an epoch, and the window is a portion of the epoch. If a correlation peak is not found in the current window, then one or more additional windows are selected within the remaining portion of the predefined time period and searched for the correlation peak until the correlation peak is found. The time estimate used to determine the correlation is used to correlate GPS signals from other GPS satellites.
BRIEF DESCRIPTION OF DRAWINGS
So that the manner in which the above recited features of the invention are attained and can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to the embodiments thereof which are illustrated in the appended drawings.
It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.
FIG. 1 depicts prior a block diagram of an object locating system;
FIG. 2 depicts a block diagram of an embodiment of GPS circuitry used in accordance with the invention;
FIG. 3 depicts a flow diagram of an embodiment of the method used in accordance with the invention; and
FIG. 4 depicts a graph of various signals processed by an embodiment of the present invention.
To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 depicts a block diagram of a location system 100 . The system 100 illustratively uses a Global Positioning System (GPS) 101 (or other similar satellite position location system) having a plurality of satellites 102 orbiting the earth. The system 100 comprises a reference station network 115 comprising a plurality of geographically dispersed reference stations where each reference station comprises fixed site GPS receivers 110 1 through 110 n (collectively fixed site GPS receiver 110 ), an aiding server 120 with software that executes GPS signal processing algorithms 142 , and at least one mobile device 130 . The mobile device 130 is coupled to, or otherwise associated with, an object that is to be located, e.g., mobile object 131 including personal assets, equipment, persons and the like. The mobile device 130 communicates with the aiding server 120 via a wireless carrier 114 (e.g., a cellular telephone network). Each reference station 110 further comprises a conventional GPS receiver 112 1 through 112 n (collectively conventional GPS receivers 112 ). For example, for a global network, the network may comprise just a few stations to observe all satellites at all times. Each of the conventional GPS receivers 112 is coupled to the aiding server 120 via a network communications link 103 .
The aiding server 120 receives the satellite information from reference station network 115 and processes the information. The processed information generally contains ephemeris, long term satellite orbit data, or other satellite tracking data. Some or all of the processed information, known as aiding information, is coupled to the wireless carrier 114 for transmission to the mobile device 130 .
The aiding server 120 provides the mobile device 130 with the aiding information such that the mobile device can compute its position. The mobile device 130 contains a wireless communications transceiver 140 that enables the receiver to communicate with the aiding server 120 through the wireless carrier 114 . The wireless carrier communicates with the server through a conventional communication network 111 .
As discussed below, the device 130 comprises a wireless transceiver 140 , a GPS receiver front end 134 , and a GPS signal processor 138 . In one embodiment, the GPS signal processor 138 includes a parallel GPS signal correlator and associated software to perform various algorithms described below. One embodiment of such a correlator is described in co-pending U.S. patent application Ser. No. 09/861,086, filed May 18, 2001, which is incorporated by reference herein in its entirety.
In one embodiment, the mobile device 130 receives aiding information (e.g., aiding data that provides one or more of satellite ephemeris, the coefficients of a pseudorange model, Doppler information, and estimated position of the device 130 ) from the aiding server 120 through the wireless link 109 , determines a position estimate for the mobile device 130 , receives GPS satellite signals, and processes the GPS signals. The mobile device 130 uses the processed GPS signals and the aiding information to compute its location. In an alternative embodiment, the device 130 provides the processed GPS signals to the wireless carrier 114 which transmits the processed signals to the aiding server 120 . The aiding server 120 uses an optional position processor 142 to further process the GPS signals from the device 130 to determine the device's location. A location requestor 122 can then request the receiver's location through a number of communications paths 105 , e.g., dial up access, Internet access, wired land line and the like. The location requester can also be the user of the mobile device 130 . In various embodiments described herein, the location can be displayed at the mobile device 130 and/or communicated through the wireless carrier 114 to the server 120 .
FIG. 2 depicts a block diagram of a global positioning system (GPS) receiver 200 incorporating the present invention. The use of a GPS receiver 200 as the platform within which the invention is incorporated forms one application of the invention. Other platforms that require signal correlation may find use for the present invention.
The receiver 200 comprises a GPS front end 134 and a GPS baseband processor 138 . The GPS front end 134 comprises a radio-frequency to intermediate frequency (RF/IF) converter 204 and an analog-to-digital converter (A/D) 206 . The front end 134 is coupled to an antenna 202 that is adapted to receive GPS signals from GPS satellites. The radio-frequency-to-intermediate-frequency converter (RF/IF converter) 204 filters, amplifies, and frequency shifts the signal for digitization by the analog-to-digital converter (A/D) 206 . The elements 202 , 204 and 206 are substantially similar to those elements used in conventional GPS or assisted GPS receivers.
The GPS baseband processor 138 comprises a plurality of processing channels 208 and a microcontroller 222 . Each processing channel 208 comprises a tuner 210 , a carrier numerically controlled oscillator (NCO) 212 , a decimation circuit 214 , a code NCO 216 , a plurality of correlators 218 , a clock 250 , and a summer 220 . The output of the A/D 206 is coupled to each of the processing channels 208 1 , 208 2 , . . . 208 n (where n is an integer) implemented in digital logic. Each processing channel 208 n may be used to process the signal from a particular GPS satellite. The signal in a particular channel is tuned digitally by the tuner 210 , driven by the carrier NCO 212 . The tuner 210 serves two purposes. First, the IF frequency component remaining after RF/IF conversion is removed to produce a baseband or near-baseband signal. Second, the satellite Doppler frequency shift resulting from satellite motion, user motion, and reference frequency errors is removed. The output from the tuner is a baseband (or near baseband) signal consisting of an in-phase component (I) and a quadrature component (Q).
A decimation circuit 214 processes the output of the tuner 210 . The output of the decimation circuit 214 is a series of complex signal samples with I and Q components, output at a rate precisely timed to match the timing of the input signal. In one embodiment of the invention, the decimation operation is a simple pre-summer that sums all the incoming signal samples over the period of an output sample. A numerically controlled oscillator (NCO) 216 is used to time the sampling process. For example, if two samples per chip of the C/A code is desired, the code NCO 216 is set to generate a frequency of (2 ×f s ), where f s is f o . (the GPS signal's C/A code chipping rate), adjusted for Doppler shift. The NCO 216 adjusts for Doppler shift based on external input from firmware commands. Because the Doppler shift is different for each satellite, a separate code NCO 216 and decimation circuit 214 is required for each channel 208 n . It should be noted that there is no requirement that the incoming sample rate be an integer multiple of the f s , as the code NCO 108 is capable of generating an arbitrary frequency. If the decimation circuit 214 is a pre-summer, the number of samples summed will typically toggle between two values, so that over the long term, the correct sample timing is maintained. For example, if the incoming sample rate is 10 MHz, and the desired sample rate is 2.046 MHz, the pre-summer will add either 4 or 5 samples, so that the desired sample rate is maintained on average.
The decimation circuit 214 may also include a quantizer (not shown) at its output to reduce the number of bits in the signal components before further processing. In one embodiment of the invention, 2-bit quantization is used.
The signal samples from decimation circuit 214 are coupled to correlators 218 1 - 218 n (hereinafter “correlators 218 ”). Each of correlators 218 is designed to produce a correlation between the input signal and a reference code (the PRN code). The reference code supplied to each of correlators 218 is shifted by one one-half “chip” of the GPS PRN code. As is well known in the art, the correlator 218 having the input signal and PRN code aligned will have a high correlation output, all the other correlators will have no output signal. The summer 220 sums all the outputs together such that if a high correlation occurs in any one of the correlators, an output signal will result from the summer 220 . The output of the summer 220 is coupled to a microcontroller 222 . The timing of the correlators 218 is controlled by a clock 250 . The local clock timing adjustment is known as a local clock bias.
The PRN code used to form the GPS signal repeats every 1023 chips i.e., one epoch. In one embodiment, to accurately correlate the signal, the correlation is performed in ½ chip intervals, i.e., requiring 2046 delays. As such, if the entire code were to be correlated at once, 2046 correlators 218 would be required for each of the I and Q signals. However, power consumption and circuit size restrictions presently make a processor having 4092 correlators impractical. As such, the GPS baseband processor comprises less that 4092 correlators, e.g., 2046 correlators with 1023 correlators used for I signal processing and 1023 correlators used for Q signal processing. These 1023 correlators for each I and Q signal are operated in accordance with the invention to facilitate finding a high correlation result as described below.
The output of each processing channel 208 is coupled to the microprocessor 222 for processing the parallel correlation results of the 2046 correlators of each processing channel. The microprocessor 222 comprises a central processing unit (CPU) 224 , support circuits 226 , and a memory 228 . The CPU 224 may be any form of microprocessor or microcontroller integrated circuit that is known in the art. The support circuits 226 are well known circuits for facilitating the operation of the CPU 224 . The support circuits 226 include, for example, one or more of the following: a cache, power supplies, clock circuits, input/output circuits, and the like. The memory 228 may be one or more of random access memory, read only memory, flash memory, and the like. The memory 228 may be used for storing correlation results as well as for storing executable software such as the correlation software 230 .
The correlation software 230 processes the correlation results, controls the timing of the code NCO 216 , as well as the timing of the clock 250 that controls PRN code delay within the correlators 218 . To facilitate full convolution of an epoch of GPS signal using less than the number of correlators available to perform the full convolution, the correlation software must repeatedly utilize the correlators in a sequential manner to compute a full convolution. However, a full convolution may not be necessary since a partial correlation result may be used for timing synchronization. For example, if enough correlators are available to correlate signals in a half of an epoch, then the correlation software 230 will delay the PRN code for 0 through 1023 half chips and perform a correlation. If no signal is found then the PRN code will be delayed 1024 through 2046 half chips and the correlation will be processed a second time. The correlation will result in either the first half of an epoch, the second half of an epoch, or not at all in some instances when no GPS signal is available. Once the delay is found that results in the correlation occurring either in the first half epoch or the second half epoch, the timing of the PRN code can be adjusted thereafter such that a correlation peak occurs for each epoch of GPS signal received. Once a correlation peak is found in channel 208 , then the timing parameters (e.g., which half epoch resulted in the correlation peak) can be used to determine a timing parameter estimate (e.g., an estimate of clock bias within the clock 250 ) for the other channels 208 2 . . . 208 n . As such, the aiding information is used in combination with the timing parameters of channel 208 1 , to reduce the search range for the other satellite signals. Using this method of deriving the timing synchronization for the GPS receiver allows for timing synchronization without computing an accurate pseudorange to the satellite.
In one embodiment of the invention, the correlators 218 during the signal acquisition process used by channel 208 1 may accumulate correlation results for multiple epochs of the GPS signal, which repeats at nominal 1 millisecond intervals. For example, if 10 milliseconds of the signal are processed, the output values are the sum of 10 correlation results each generated over one epoch. All the individual correlations should have a similar characteristic, since the timing of the decimation operation ensures that samples are taken at the same relative moment within each epoch. Accumulating similar results from individual correlations improves the signal to noise ratio, enhancing the ability of the receiver to detect weak signals. This processing may be referred to as coherent integration and can be combined with magnitude integration to yield correlation results averaged over a time period of up to several seconds.
FIG. 3 depicts a flow diagram of software for implementing a correlation method 300 of the present invention. The method 300 begins at step 302 , and proceeds to step 303 wherein the method 300 selects a first GPS satellite signal for processing, e.g., channel 208 1 is tuned to receive signals from a first satellite. At step 304 , the method 300 defines a period of correlation (“window”) equal to a range of delays within a predefined time period (i.e., a range of relative delays between the received satellite signal and the corresponding pseudorandom reference code). For a GPS signal, the predefined time period is one epoch of 1023 chips in length and the window is a portion of the epoch. For other digital signals, the predefined time period may other lengths of digital code. In one embodiment, the window is selected to be one-half of an epoch.
At step 306 , the parallel correlators are used to correlate the received satellite signal across the window defined at step 304 , wherein a PRN reference code is delayed by a half a chip in each correlator. As described above, there are 1023 correlators that correlate on half chip increments of the 1023 chips within the PRN code of the GPS signal. At step 308 , the method 300 queries whether a correlation peak was found within the half epoch that was processed. If a high correlation peak was found, the method 300 proceeds to step 312 , knowing that the PRN code needs to be delayed to a time within the half epoch. If the correlation peak is not found in step 308 , then the method 300 proceeds to step 310 , where another window within the predefined time period is selected (i.e., another range of delays). For example, the window selected at step 310 may be the second half of the epoch. The method 300 then proceeds to step 306 , where the correlation is repeated for the newly selected window. In this manner, the PRN code phase delay or timing can be determined to within a half epoch without computing an accurate pseudorange to the first satellite.
At step 312 , timing parameters are determined and used to correlate other GPS satellite signals. Notably, each processing channel 208 2 through 208 n will perform a correlation using the timing parameters of the first channel in combination with the aiding information. More specifically, the result of the first channel is used to bound the clock 250 in the GPS receiver, e.g., a delay range is known to be in the half epoch. The method 300 ends at step 314 .
Although the above embodiment has been described with respect to a window equal to one half of an epoch, those skilled in the art will realize that other windows or range of delays may be used to perform correlation of a digital signal. For example, with a GPS epoch being 1023 chips long, if the correlation period were one fourth of an epoch, where 512 correlators were used in the correlation method of FIG. 3 , then 512 correlations would be performed at most four times to identify which one fourth of an epoch the correlation occurs. As such the timing parameter, e.g., the local clock bias, would be found to an accuracy of within one fourth of an epoch. Other alternative techniques may be used to perform the timing estimation. Such procedures include using a half epoch correlation period that is staggered by one third of an epoch, using a period of one third of an epoch, and so on.
FIGS. 4A-4D graphically depict an exemplary process for performing signal correlation in accordance with the invention. FIG. 4A depicts a predefined period 402 having 2046 samples of 1023 PN code chips. FIG. 4B depicts two correlation periods 406 and 408 used to correlate in half epoch increments. In the present example, a correlation performed within the period 406 produces noise (i.e., a correlation is not present within the first half epoch). A shown in FIG. 4C , a correlation is then performed within the period 408 to produce a high correlation output (i.e., a correlation is present within the second half epoch). For example, a plurality of high correlation peaks 410 resulting from repeated correlations during the second half epoch of the signal are shown. Generally, the software as described above will integrate a number of correlation results to achieve an accurate correlation peak 412 , as depicted in FIG. 4D . The peak 412 clearly shows that the PRN code phase is estimated to be within the second half epoch. As such, a timing parameter may be derived and used in combination with the aiding information to receive other GPS signals from other satellites. As such, signal acquisition may be performed without determining an accurate pseudorange to the satellite.
Although various embodiments, which incorporate the teachings of the present invention have been shown and described in detail herein, those skilled in the art can readily devise many other varied embodiments that still incorporate these teachings.
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A method of correlating a digital communications signal is described. In an example, a window is defined equal to a portion of an epoch of the digital communication signal. The digital communication signal is then correlated across the window. A determination is made as to whether a correlation peak results from the correlating. Timing parameters are then established for receiving additional digital communication signals in response to presence of the correlation peak.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. application Ser. No. 11/611,315, filed on Dec. 15, 2006 which is a continuation of U.S. application Ser. No. 11/325,169 filed Jan. 4, 2006(now U.S. Pat. No. 7,159,588), which is a continuation of U.S. application Ser. No. 10/950,926 filed Sep. 27, 2004 (now U.S. Pat. No. 7,013,893), which is a continuation of Ser. No. 09/924,325 filed Aug. 8, 2001 (now U.S. Pat. No. 6,814,073) which claims priority filing date from U.S. Provisional Application No. 60/228,630 filed Aug. 29, 2000, all of which are hereby incorporated herein by reference.
FIELD OF THE INVENTION
[0002] This invention relates to a method and apparatus for detecting obstruction of the airway of a patient. More specifically, the invention involves an improved method and apparatus for detecting obstruction, either partial or complete, based upon a flattened measure of an inspiratory portion of respiratory airflow. The method is useful in patient ventilators such as those used in the diagnosis and treatment of respiratory conditions including sleep apnea or hypopnea.
BACKGROUND OF THE INVENTION
[0003] The dangers of obstructed breathing during sleep are well known in relation to the Obstructive Sleep Apnea (OSA) syndrome. Apnea, hypopnea and heavy snoring are recognized as causes of sleep disruption and risk factors in certain types of heart disease.
[0004] The monitoring of upper airway pressure-flow relationships in obstructive sleep apnea has been described in Smith et al., 1988, J. Appl. Physiol. 64: 789-795. FIG. 1 of that article shows polygraphic sleep recordings at varying levels of increasing nasal pressure. It was noted that inspiratory volumetric flow plateaued in certain breaths suggesting the presence of airflow limitation. Pressure-flow curves were constructed by plotting midinspiratory airflow against either mask pressure or endoesophageal pressure. The pressure-flow plots of nasal pressure against mean midinspiratory flow were then fit by least-squares linear regression to calculate resistance upstream to the collapsible site.
[0005] The effect of positive nasal pressure on upper airway pressure-flow relationships has been described in Schwartz et al., 1989, J. Appl Physiol. 66: 1626-1634. FIG. 4 of the article shows that pressure-flow tracings plateau at a low pressure level. It was further shown when the pressure was increased, flow did not plateau.
[0006] The common method of treatment of these syndromes is to administer Continuous Positive Airway Pressure (CPAP). The procedure for administering CPAP treatment has been documented in both the technical and patent literature. Briefly stated, CPAP treatment acts as a pneumatic splint of the airway by the provision of a positive pressure, usually in the range 4-20 cm H 2 O. The air is supplied by a motor driven blower whose output passes via an air delivery device to sealingly engage a patient's airway. A mask, tracheotomy tube, endotracheal tube, nasal pillows or other appropriate device may be used. An exhaust port is provided in a delivery tube proximate to the air delivery device. Other forms of CPAP, such as bi-level CPAP, and self-titrating CPAP, are described in U.S. Pat. Nos. 5,148,802 and 5,245,995 respectively.
[0007] With regard to the control of CPAP treatment, various techniques are known for sensing and detecting abnormal breathing patterns indicative of obstruction. For example, U.S. Pat. No. 5,245,995 describes how snoring and abnormal breathing patterns can be detected by inspiration and expiration pressure measurements while sleeping, thereby leading to early indication of preobstructive episodes or other forms of breathing disorder. Particularly, patterns of respiratory parameters are monitored, and CPAP pressure is raised on the detection of pre-defined patterns to provide increased airway pressure to ideally prevent the occurrence of the obstructive episodes and the other forms of breathing disorder.
[0008] Similarly, U.S. Pat. No. 5,335,654 (Rapoport) lists several indices said to be indications of flow limitation and/or partial obstruction patterns including: (1) The derivative of the flow signal equals zero; (2) The second derivative between peaks of the flow signal is zero for a prolonged interval; (3) The ratio of early inspirational flow to midinspirational flow is less than or equal to 1. The patent further lists events said to be indications of obstructions: (1) Reduced slope of the line connecting the peak inspiratory flow to the peak expiratory flow; (2) Steep upward or downward stroke (dV/dt) of the flow signal; and (3) Ratio of inspiratory flow to expiratory flow over 0.5.
[0009] U.S. Pat. No. 5,645,053 (Remmers) describes calculating a flatness index, wherein flatness is defined to be the relative deviation of the observed airflow from the mean airflow. In Remmers, individual values of airflow are obtained between 40% and 80% of the inspiratory period. The mean value is calculated and subtracted from individual values of inspiratory flow. The individual differences are squared and divided by the total number of observations minus one. The square root of this result is used to determine a relative variation. The relative variation is divided by the mean inspiratory airflow to give a relative deviation or a coefficient of variation for that breath.
[0010] In commonly owned U.S. Pat. No. 5,704,345, Berthon-Jones also discloses a method for detecting partial obstruction of a patient's airway. Generally, the method involves a determination of two alternative obstruction index values based upon the patient's monitored respiratory airflow. Either obstruction index may then be compared to a threshold value. Essentially, the index values may be characterized as shape factors that detect a flattening of an inspiratory portion of a patient's respiratory airflow. The first shape factor involves a ratio of the mean of a midportion of the inspiratory airflow of the breathing cycle and the mean of the inspiratory airflow. The formula for shape factor 1 is as follows:
[0000]
shapefactor_
1
=
1
33
∑
t
=
16
48
f
s
(
t
)
M
[0000] where f s (t) is a sample of the patient's inspiratory airflow and M is the mean of inspiratory airflow given by the following:
[0000]
M
=
1
65
∑
t
=
1
65
f
s
(
t
)
[0000] A second shape factor involves a ratio of the Root Mean Square deviation of a midportion of inspiratory airflow and the mean inspiratory airflow according to the formula:
[0000]
shapefactor_
2
=
1
33
∑
t
=
16
48
(
f
s
(
t
)
-
M
)
2
M
[0000] Berthon-Jones further discloses a scaling procedure applied to the inspiratory airflow samples such that the mean M of the samples f s (t) is unity (M=1). This scaling procedure simplifies both shape factor formulas. Additional adjustments to f s (t) including averaging and the elimination of samples from erratic breaths such as coughs, sighs, hiccups, etc., are also taught by Berthon-Jones. The foregoing U.S. patent is hereby incorporated by reference.
[0011] The present invention involves an improved method and apparatus for detecting some forms of obstruction based upon the flattening of the inspiratory airflow.
BRIEF SUMMARY OF THE INVENTION
[0012] An objective of the present invention is to provide an apparatus in which obstruction, either partial or complete, of the patient's airway is detected by analyzing respiratory airflow.
[0013] A further objective is to provide an apparatus in which a novel algorithm for detecting airway obstruction is implemented without using additional components or making substantial changes to the structure of existing respiratory apparatus.
[0014] Accordingly, a respiratory apparatus is provided in which the respiratory airflow of a patient is continuously monitored. The part of respiratory airflow associated with inspiration is identified and sampled. From these inspiration samples, several samples representing a midportion of inspiration are identified. One or more weighting parameters or weighting factors are associated with each midportion sample. These weights and midportion samples are then used to calculate an obstruction index. Finally, this obstruction index is compared to a threshold value which comparison is used to adjust or control ventilatory assistance.
[0015] In one embodiment, weighting factors are applied based on whether the inspiratory airflow samples are less than or greater than a threshold level, such as the mean airflow.
[0016] In another embodiment, different weighting factors are applied to samples based on their time positions in a breath. Samples taken prior to a certain event during inspiration, for example, samples preceding the half way point of inspiration, are assigned lower weighting factors than samples succeeding the event. An obstruction index is then calculated using these samples with their corresponding weighting factors.
[0017] In one aspect, the subject invention pertains to a respiratory apparatus which includes a gas source adapted to selectively provide pressurized breathable gas to a patient, a flow sensor to sense the respiratory airflow from the patient and to generate an airflow signal indicative of airflow, an obstruction detector coupled to said flow sensor which includes a weight assigning member arranged to assign several weight factors to portions of the flow signal and to generate an obstruction signal using the weighted portions, and a controller coupled to the flow sensor and arranged to control the operation of the gas source, receive the obstruction signal and alter the operation of the gas source in response to the obstruction signal.
[0018] Another aspect of the invention concerns an apparatus for monitoring and/or treating a patient having a sleep disorder, the apparatus including a flow sensor that senses patient respiration and generates a corresponding flow signal; and an obstruction detector coupled to the flow sensor and adapted to determine a weighted average signal, the weighted average signal being dependent on a weighted average of the flow signal in accordance with one of an amplitude and a time position of portions of the flow signal, the obstruction detector including a signal generator that generates a signal indicative of an airway obstruction based on the weighted average signal.
[0019] A further aspect of the invention concerns an apparatus for treating a patient having a sleep disorder, the apparatus comprising a mask, a gas source selectively supplying pressurized breathable air to the patient through the mask, a flow sensor that senses airflow and generates a flow signal indicative of respiration, an obstruction detector coupled to the flow sensor and adapted to determine a weighted average signal, the weighted average signal being dependent on a weighted average of the flow signal in accordance with one of an amplitude and a time position of portions of the flow signal, and a controller receiving the obstruction signal and generating in response a command for activating the gas source.
[0020] Another aspect of the invention concerns a method for detecting obstruction in the airways of a patient, including measuring an air flow of the patient, detecting a predetermined section of said air flow, assigning weights to portions of said predetermined section and determining an index value for said predetermined section based on said weights as a measure of the obstruction.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] FIG. 1 shows a block diagram of a respiratory apparatus constructed in accordance with this invention.
[0022] FIG. 2 shows a flow chart illustrating the operation of the apparatus of FIG. 1 .
[0023] FIG. 3 shows the inspiration phases of typical respiration signals for a healthy person and a person with a partial airway obstruction.
[0024] FIG. 4 shows a portion of a normal respiration signal from a patient.
[0025] FIGS. 5 and 6 show portions of two different respiration signals characteristic from patients with sleep apnea.
[0026] FIG. 7 shows a flow chart for determining the flattening indices for the respiration signals of FIGS. 4-6 .
[0027] FIG. 8 shows a normal breathing pattern for a person without respiratory obstructions to illustrate the determination of two improved obstruction indices.
[0028] FIGS. 9 , 10 , and 11 show various breathing patterns with obstructions identifiable using the improved indices.
[0029] FIG. 12 shows an example of how a flow curve can be checked to insure that it is a valid respiration curve.
[0030] FIG. 13 shows an example of how a typical respiration flow curve can be trimmed.
DETAILED DESCRIPTION
[0031] Apparatus and Methodology
[0032] FIG. 1 shows an example respiratory apparatus 10 constructed in accordance with the invention. The respiratory apparatus 10 includes a mask 12 connected to a blower 14 by a flexible tube 16 . The mask 12 is fitted to the patient and may be either a nose mask or a face mask. The blower 14 with an air outlet 22 is driven by a motor 18 in accordance with control signals from a servocontroller 20 . This arrangement allows the respiratory apparatus 10 to deliver pressurized air (or air enriched with oxygen from a source, not shown). The pressurized air is delivered by tube 16 to the mask 12 . The tube 16 is provided with a narrow exhaust port 26 through which air exhaled by the patient is expelled.
[0033] A control circuit 24 is used to control the operation of servocontroller 20 and motor 18 using certain predetermined criteria, thereby defining modes of operation for the apparatus 10 . Preferably, in accordance with this invention, the control circuit 24 is adapted to operate the apparatus 10 to provide CPAP to the patient.
[0034] Control circuit 24 includes a flow restrictive element 28 . Tubes 30 and 31 lead from restrictive element 28 to a differential pressure transducer 34 . Tube 30 is also connected through another tube 33 to a mask pressure transducer 32 .
[0035] The mask pressure transducer 32 generates a first electrical signal which is amplified by an amplifier 36 to generate an output P(t) proportional to the air pressure within the mask 12 . This output is fed directly to the servocontroller 20 .
[0036] The differential pressure transducer 34 senses the differential pressure across the flow restrictive element 28 , which differential pressure is related to the air flow rate through the flow restrictive element 28 and tube 16 . Differential pressure transducer 34 generates a second electrical signal that is amplified by an amplifier 38 . This amplified signal F(t) is termed an air flow signal since it represents the air flow through the tube 16 .
[0037] The air flow signal F(t) is fed to a filter 40 which filters the signal within a preset range. The outputs of the filter 40 and amplifier 36 are fed to an ADC (analog-to-digital) converter 42 , which generates corresponding signals f 1 to a microprocessor 44 . The microprocessor 44 generates analog control signals that are converted into corresponding digital control signals by DAC 46 and used as a reference signal Pset (t) for the servo 20 .
[0038] One method for the operation of a respiratory apparatus 10 is shown in the flow chart of FIG. 2 . Individuals skilled in the art will recognize other methodologies for utilizing the improved flow flattening index that is disclosed herein. The embodiment of the methodology of FIG. 2 is also detailed in U.S. Pat. No. 5,704,345 (the '345 patent). The first step 100 is the measurement of respiratory flow (rate) over time. This information is processed in step 102 to generate Index values to be used as qualitative measures for subsequent processing. Thus, Step 102 includes the generation of obstruction index values based upon the weighting method as disclosed herein. Step 104 detects whether an apnea is occurring by comparison of the breathing Index with a threshold value.
[0039] If the answer in step 104 is “Yes”, an apnea is in progress and there then follows a determination of patency in step 110 . If there is patency of the airway, a central apnea with an open airway is occurring, and, if desired, the event is logged in step 112 . If the result of step 110 is that the airway is not patent, then a total obstructive apnea or a central apnea with closed airway is occurring, which results in the commencement or increase in CPAP treatment pressure in step 108 . If desired, step 108 may include the optional logging of the detected abnormality.
[0040] If the answer in step 104 is “No”, one or more obstruction indices, such as the improved flow flattening indices, are compared with threshold values in step 106 , by which the determination of obstruction of the airway is obtained. If the answer is “Yes” in step 106 , then there is a partial obstruction, and if “No”, there is no obstruction (normalcy).
[0041] Step 108 applies in the case of a complete or partial obstruction of the airway a consequential increase in CPAP treatment pressure. In the instance of normal breathing with no obstruction, the CPAP treatment pressure is reduced, in accordance with usual methodologies that seek to set the minimal pressure required to obviate, or at least reduce, the occurrence of apneas. The amount of reduction in step 107 may, if desired, be zero. Similarly, in the event of a central apnea with patent airway (step 110 , 112 ) treatment pressure is not increased. Such increases in pressure reflexively inhibit breathing, further aggravating the breathing disorder.
[0042] Improved Flow Flattening Indices
[0043] FIG. 3 depicts an airflow signal with respect to the inspiratory portion of a typical breathing cycle. During the inspiratory portion of the breathing cycle of a healthy person, the airflow rises smoothly with inspiration, reaches a peak and falls smoothly to zero. However, a patient with a partially obstructed airway exhibits a breathing pattern characterized by a significant flat zone during inspiration. Theoretically, for an obstructed flow, as the degree of partial obstruction increases, the airflow signal for inspiration would tend to a square wave.
[0044] As previously discussed, the '345 patent describes two shape factors useful in testing for a flattening of the inspiratory portion of a patient's breathing cycle. In the preferred embodiment of the invention, the resulting obstruction index or flow flattening index (FFI) for each shape factor may be compared to unique threshold values. While the approach works well in many instances, it may not detect certain obstruction patterns.
[0045] This can be illustrated by an examination of FIGS. 4-6 . FIGS. 4-6 depict portions of respiration cycles. FIG. 4 shows a normal respiration flow and FIG. 5 shows a severely obstructed respiration cycle in which the inspiration period is characterized by two high positive lobes A and B and a relatively flat zone C between lobes A and B. In FIG. 4 , the RMS deviation is indicated by the shaded area under the respiration flow curve and above the mean inspiration flow. In FIG. 5 , the RMS deviation is indicated by the shaded area above the respiration flow curve and below the mean inspiration flow. As seen in FIG. 5 , due to obstruction, the mean inspiration flow is greater than it would be without the second positive lobe B. Therefore, when analyzing the flow using shape factors of the '345 patent, the highly restricted and abnormal flow of FIG. 5 would not be detected as an obstruction.
[0046] Similarly, FIG. 6 shows another possible respiration curve for a patient with a partial airway obstruction. This curve includes an abnormally wide initial positive lobe D preceding a flat portion E. Once again, because of the large lobe D the mean inspiration flow is higher than for the more typical flow of FIG. 3 . Using the prior art obstruction index, this condition may be detected as normal rather than being properly detected as an obstructed flow.
[0047] In order to detect these obstructions while continuing to properly respond to non-obstructed flows like the one of FIG. 4 , the present invention assigns different weighting factors to the inspiration flow samples depending on:
(a) the magnitude of each sample with respect to the mean inspiration flow; and (b) the time-wise position of each sample with respect to a time reference such as mid-inspiration.
[0050] By assigning a different weighting factor to a sample that is less than a particular value, for example, the mean flow, during the obstruction index or FFI calculation, there is an improved sensitivity to the respiration signal of FIG. 5 without affecting the FFI for normal breathing where most of the flow is greater than the mean.
[0051] Similarly, by assigning a different weighting factor to samples that occur after a time reference point, the subsequent samples become more significant. This improves sensitivity to the respiration signal of FIG. 6 without affecting the FFI for other breaths that are symmetrical in time about the center point of the inspiration.
[0052] An algorithm using one form of the invention for calculating the improved FFI is shown in FIG. 7 . In step 100 of FIG. 2 , a typical flow rate curve F (defined by a plurality of samples f i where i is an index from 1 to the total number of samples n) is obtained. In step 200 of FIG. 7 , the curve F is checked to insure that it is a valid inspiration curve. Next, in step 201 the curve F is trimmed to eliminate all samples f i outside of the inspiration period. Methods of implementing steps 200 and 201 are discussed in more detail below. In step 202 , a mean M is calculated for all the inspiration samples 1 through n using conventional techniques.
[0053] In step 204 two weighting factors which may be designated as value dependent factors w i and time dependent factors v i are assigned to each of the samples f i based respectively on the amplitude of each sample and its time position in relation to the inspiration mean M and its center point respectively. For example, the factors w i and v i may be assigned for each flow measurement f i using the following rules:
[0054] A1. If f i >M then w i =1
[0055] A2. If f i <M then w i =0.5
[0056] B1. If f i is taken prior to the inspiration center point, then v i =0.75.
[0057] B2. If f i is taken after the inspiration center, then v i =1.25.
[0058] Next, in step 206 two alternative FFI or obstruction indices are calculated using the formulas:
[0000]
value_weighted
_index
=
∑
i
=
j
k
W
i
·
f
i
-
M
M
·
d
time_weighted
_index
=
∑
i
=
j
k
V
i
·
f
i
-
M
M
·
d
[0059] Where j is the first and k is the last sample relative to a midportion or center half of the inspiration curve F and d is the number of samples of the midportion of inspiration or center half as shown in FIGS. 3-6 , and M is the mean of the inspiration curve F.
[0060] Alternatively, the algorithm may be described by the following steps:
Check the flow samples to confirm they represent a valid inspiration cycle with a shape within acceptable bounds. Trim samples from any “pre-inspiratory period”; Find the mean of the inspiration flow samples; Sum the weighed absolute difference of the flow samples from mean for samples in the center half or mid portion of inspiration:
If flow sample is >mean, sum the difference (flow-mean); If flow sample is <mean, sum ½ the difference; If flow sample is before the center point of the inspiration, use 75% of the difference from above; If flow sample is after the center point of the inspiration, use 125% of the difference from above;
Scale the sum by the mean and inspiration time to produce the flattening index: FFI=weighed absolute sum/(Center half time*mean inspiration flow).
[0070] As discussed above, in step 200 of FIG. 7 , the curve F is checked to insure that it corresponds to a valid inspiration curve. The flow curve F is checked against an upper and lower bound to prevent processing of an inspiratory curve corrupted by a cough, sigh, etc. For example, as shown in FIG. 12 , the curve F may be rejected if it exceeds at any time an upper limit curve UL or falls below a lower limit curve LL. UL may be selected at about 150% of the mean inspiratory flow and LL may be selected at about 50% of the mean inspiratory flow.
[0071] In step 201 the respiration curve is trimmed to eliminate samples f i occurring before the actual inspiration period. One method of trimming includes the steps:
[0072] (1) determine the point where the flow reaches 75% of the peak inspiratory flow;
[0073] (2) determine the point where the flow reaches 25% of the peak inspiratory flow;
[0074] (3) extrapolate a line through these two points to the zero flow line to determine the point at the beginning of inspiration but use the first sample if the point is to the left of the first sample.
[0075] This trimming method is illustrated in FIG. 13 . With reference to the figure, the respiration curve F crosses the zero flow level at T 0 . Once the maximum inspiratory flow is reached, two intermediate flow levels are determined: the ¼ inspiratory flow level (i.e. the flow equaling 25% of the maximum inspiratory flow) and the ¾ inspiratory flow level (i.e. the flow equaling 75% of the maximum inspiratory flow). In FIG. 13 , curve F crosses these two levels at points F 1 and F 2 , respectively. Using the times T 1 and T 2 , corresponding to the points F 1 and F 2 , the curve F is approximated by a line L. This line is then extended to the zero flow level to determine an extrapolated time TS as the starting time for inspiration period for curve F. Samples f 1 obtained prior to TS are ignored.
[0076] The improvement resulting from the use of the above described value and time weighted obstruction indices can be seen with an examination of simulated tests. To this end, FIGS. 8 , 9 , 10 and 11 show breathing patterns of patients with both normal and obstructed respiration. These patterns were analyzed using the weighted indices of the present invention, as well as the shape factor 2 that uses equal weight samples f i as described in the '345 patent. The results of the tests are shown in the table below.
[0000]
TABLE I
Time weighted
Equal weight Index
Value weighted index
index
FIG. 8
0.26
0.25
0.25
FIG. 9
0.24
0.139
0.133
FIG. 10
0.31
0.18
0.13
FIG. 11
0.37
0.27
0.23
[0077] The weighted indices range from 0.3, which indicates no flattening or obstruction, to 0, which indicates gross obstruction. The separation point between these two classifications is 0.15, which may be used as a threshold value for comparison as described below.
[0078] FIG. 8 shows a normal breathing pattern. As can be seen from the table, all three indices have approximately the same value, thereby indicating that no increase in CPAP is needed.
[0079] FIG. 9 is similar in form to FIG. 5 in that it shows a pattern with two lobes separated by a relatively flat region. As seen in the table, if the equal weight index is used, no obstruction is found, while both improved indices are below the threshold and, therefore, both indicate an obstructed breathing pattern.
[0080] FIG. 10 shows a pattern similar to the one in FIG. 6 that starts off with a high initial lobe and then decays relatively slowly. For this pattern, the equal weight index and the value weighted index are both above the threshold. However, the time weighted index is below the threshold indicating an obstructed breathing pattern.
[0081] Finally, FIG. 11 shows another normal breathing pattern which has a shape somewhat different from the shape shown in FIG. 8 . The three indices in the Table are all above the threshold level thereby indicating a normal pattern as well.
[0082] Although the invention has been described with reference to a particular embodiment, it is to be understood that this embodiment is merely illustrative of the application the principles of the invention. Thus, it is to be understood that numerous modifications may be made in the illustrative embodiment of the invention and other arrangements may be devised without departing from the spirit and scope of the invention. For example, while the preferred embodiment of the invention applies weighted samples to formulae which are used to identify a flattening of airflow, a similar method might be used with other formulae that detect roundness of flow or its deviation there from using a sinusoidal or other similar function.
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In a respiratory apparatus for treatment of sleep apnea and other disorders associated with an obstruction of a patient's airway and which uses an airflow signal, an obstruction index is generated which detects the flattening of the inspiratory portion of the airflow. The obstruction index is used to differentiate normal and obstructed breathing. The obstruction index is based upon different weighting factors applied to sections of the airflow signal thereby improving sensitivity to various types of respiration obstructions.
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BACKGROUND
[0001] 1. Field of the Invention
[0002] The present invention relates generally to magnetic sensors, and more particularly, to magnetic sensors integrated with semiconductor devices.
[0003] 2. Background of the Invention
[0004] Magnetoelectronics is a growing field that is devoted to the development of electronic device structures that incorporate a ferromagnetic element. As shown in FIG. 1, when a write current (Iw) is applied to an integrated, contiguous write wire 11 that is directly over a ferromagnetic element 12 , a magnetic field (H) is generated that is parallel with and close to a surface of the write wire 11 . The magnitude of the magnetic field (H) is determined by an inductive coefficient (α) and the write current (Iw), i.e., H=αIw. The magnetization of the ferromagnetic film is a function of the magnetic field and follows a hysteresis loop like that shown in FIG. 2.
[0005] The bi-stable orientation characteristic of the hysteresis loop of FIG. 2 is a defining characteristic of ferromagnetic materials and a natural basis for nonvolatile bit storage. Basically, when the magnetic field is larger than a switching field (Hs), the magnetization of the ferromagnetic film reaches a first saturation value (Ms). The magnetization is thereafter maintained at this first saturation value and particular orientation for periods as long as years, even when power is removed. The orientation of the magnetization changes when a magnetic field with a reversed direction is applied to the ferromagnetic element. The magnetization, however, drops down slightly when the reversed magnetic field is applied until the reversed magnetic field is less than −Hs. In this situation, the magnetization and output voltage jump promptly from the first saturation value (Ms, Vout) to the second saturation value (−Ms, −Vout), as shown in FIG. 2. The magnetization state is then maintained at the second saturation value for extremely long periods unless the magnetic field reaches Hs again.
[0006] Magnetoelectronic devices leverage the hysteresis-loop characteristic of ferromagnetic material to perform specific functions, such as “latching” data, Boolean operations and like functions. To detect a result of a Boolean operation, for example, magnetoelectronic devices also require a magnetic field sensor to detect the magnetic field induced by the ferromagnetic material.
[0007] Magnetic field sensors based on the Hall-effect are presently the most widely used magnetic sensor. When a magnetic field is applied perpendicularly to an electric conductor, a voltage is generated transversely to a current flow direction in the electric conductor. This phenomenon is called the Hall effect and the voltage generated is called Hall voltage. Therefore, magnetoelectronic devices typically utilize a Hall sensor to sense the orientation of the magnetic field induced by a magnetic element.
[0008] One example of a magnetoelectronic device is described in Mark Johnson et al.'s article entitled “Hybrid Hall Effect Device” which was first published in 1997. In Johnson et al.'s article, a single microstructured ferromagnetic film and a micro scale Hall cross are fabricated together to create a magnetoelectronic device. Magnetic fringe fields from the edge of the ferromagnet generate a Hall voltage in the Hall cross. The sign of the fringe field, as well as the sign of the output Hall voltage, is switched by reversing the magnetization of the ferromagnet. The Hall cross thus detects the Hall voltage and outputs a value (high or low) corresponding to the direction of the magnetization of the ferromagnet.
[0009] Hall sensors are not only used for detecting a magnetic field. Hall sensors also provide signals that can be used for implementing various sensing and control functions. Discrete Hall sensors, coupled with current-excitation and signal-conditioning blocks, provide a voltage output in the presence of a magnetic field. A number of integrated circuit sensor ICs ease the design task by combining Hall sensors and peripheral circuitry to provide linear or switched outputs. The majority of presently-available Hall sensors are low-cost discrete devices. The allure of contactless sensing, low parts cost, and easy design-in make Hall devices the sensors of choice in hundreds of automotive, aircraft, appliance, and tool applications.
[0010] [0010]FIG. 3 represents a discrete Hall sensor device 30 consistent with known vertical Hall (VH) technology. As shown, sensor device 30 comprises five contacts 301 - 305 arranged in a line on top of a deep n-type wafer 310 of about 30 μm. In addition, two P-diffusion wells 320 laterally surround an active area of the Hall sensor device where contacts 301 - 305 are located. In operation, contact 303 is supplied with a supply voltage Vs and contacts 301 and 305 are grounded so that when a magnetic field Hs, having a direction oriented into the paper is applied, current flows are generated from contact 303 to contacts 302 and 304 , and to contacts 301 and 305 . Hall voltages VH+ and VH− are thus generated and can be detected at contacts 302 and 304 .
[0011] [0011]FIG. 4 is a schematic diagram showing the distribution of the current flow within the deep n-type substrate 310 . As the deep n-type substrate 310 has a depth of about 30 μm, sensor device 30 is open downwards and allows a deep current flow. Since the sensitivity of a Hall sensor decreases as the sensing distance increases, new miniaturization techniques that increases the sensitivity of a Hall sensor device are desirable.
[0012] A present trend is to integrate Hall sensors with semiconductor integrated circuits instead of employing discrete Hall sensor ICs. Such integration allows a system approach thereby improving the sensor performance despite the mediocre characteristics of basic Hall cells. Among various integrated circuits, CMOS integrated circuits (Complementary Metal Oxide Semiconductor) are considered preferred over bipolar integrated circuits because CMOS provides a higher level of integration and lower power and cost.
[0013] One example of integrating Hall sensors with CMOS is disclosed by E. Schurig et al. in the article entitled “A Vertical Hall Device in CMOS High-Voltage Technology”. The vertical Hall sensor described in this article is built in bulk CMOS, which has a cross-sectional view as shown in FIG. 5.
[0014] Similar to the conventional VH sensor of FIG. 3, Hall sensor device 50 of FIG. 5 also comprises five contacts 501 - 505 . These five contacts 501 - 505 , however, are arranged in a line on top of a low-doped, active n-diffusion region 510 , which has a depth of about 7 μm. In this known Hall sensor structure, the sensor device 50 also comprises two P-diffusion wells 520 laterally surrounding the active area of the Hall sensor 50 .
[0015] As the n-diffusion layer 510 in this device has a depth of about 7 μm, the current flow distribution in the sensor can be limited to 7 μm, as shown in a distribution diagram of FIG. 6. With the distribution distance decreased, the concentration of the current flow is closer to the contacts 502 and 504 . Thus, the sensitivity of the Hall sensor device to the magnetic field is increased compared to that of the VH sensor device of FIG. 3.
[0016] Although Hall sensor device 50 of FIG. 5 has increased sensitivity for detecting a magnetic field in comparison with the VH sensor of FIG. 3, a Hall sensor device having still higher sensitivity is always desired as it helps to simplify overall system designs, reduce cost, and decrease power consumption.
SUMMARY OF THE INVENTION
[0017] One aspect of the present invention is to provide a magnetic sensor integrated with CMOS. The present invention is particularly applicable in SOI (Silicon on Insulator) CMOS which extends standard bulk CMOS to a very high integration level, high temperature environment or radiation hard applications.
[0018] Another aspect of the present invention is to provide a magnetic sensor integrated with SOI CMOS in which vertical Hall sensors are fabricated in combination with gate regions that are maintained at predetermined potentials by associated gate electrodes.
[0019] The features of the present invention and attendant advantages thereof will be more fully understood upon a reading of the following detailed description along with the associated drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] [0020]FIG. 1 is a schematic diagram illustrating the magnetic field induced along a surface of a thin ferromagnetic film when a write current is applied adjacent the film.
[0021] [0021]FIG. 2 is a diagram showing a hysteresis loop of a ferromagnetic element.
[0022] [0022]FIG. 3 is a cross-sectional view of a conventional VH sensor structure.
[0023] [0023]FIG. 4 is a current distribution diagram of the conventional VH sensor of FIG. 3.
[0024] [0024]FIG. 5 is a cross-sectional view of a conventional Hall sensor device which is fabricated in a bulk CMOS process.
[0025] [0025]FIG. 6 is a current distribution diagram of the conventional Hall sensor device of FIG. 5.
[0026] [0026]FIG. 7 is a layout of a vertical Hall sensor that is fabricated integrally with SOI CMOS in accordance with the present invention.
[0027] [0027]FIG. 8 is a cross-sectional diagram of the vertical Hall sensor of FIG. 7.
[0028] [0028]FIG. 9 is a current distribution diagram of in the vertical Hall sensor of FIG. 7.
[0029] [0029]FIG. 10 is a cross-sectional diagram viewed from line 10 - 10 of FIGS. 14-17, showing the gate regions are isolated with oxides or PN junctions.
[0030] [0030]FIG. 11 shows relationship curves of sensitivity versus bias voltage which were obtained by experiment with a vertical Hall sensor in accordance with the present invention.
[0031] [0031]FIG. 12 shows relationship curves of bias current versus bias voltage and differential Hall voltage versus bias voltage which were obtained by experiment with a vertical Hall sensor in accordance with the present invention, in which a gate voltage was maintained at 4V.
[0032] [0032]FIG. 13 shows relationship curves of bias current versus bias voltage and differential Hall voltage versus bias voltage which were obtained by experiment with a vertical Hall sensor in accordance with the present invention, in which a gate voltage was maintained at 0V.
[0033] [0033]FIG. 14 shows a layout of a cross-shaped island isolated sensor in accordance with another embodiment of the present invention.
[0034] [0034]FIG. 15 shows a layout of a diamond-shaped island isolated sensor in accordance with yet another embodiment of the present invention.
[0035] [0035]FIG. 16 shows a layout of a pn junction island isolated sensor in accordance with still another embodiment of the present invention.
[0036] [0036]FIG. 17 shows a layout of a gated island isolated sensor in accordance with yet another embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0037] The present invention provides a Hall sensor device that can be fabricated integrally with SOI (silicon on isolator) CMOS. SOI CMOS has a capability of extending the standard bulk CMOS to a high temperature environment or radiation hard applications It also is becoming a technology of choice for next generations of very dense integrated circuits. In the case of bulk CMOS, as shown in FIG. 3, P/N type MOS transistors are isolated from a well layer such as n-well region 310 . The PN junction formed between wells in bulk transistors do not exist as complete depletion type transistors. Also, the junction capacity is very small. Therefore, the Hall sensor device is not coupled with an amplification device like a transistor that may increase the overall sensitivity.
[0038] In contrast, according to the present invention, a SOI CMOS device, of which a cross-sectional view is illustrated in FIG. 8, a Si supporting substrate ( 810 in FIG. 8) and buried oxide film 820 are provided. Also, the device is structured such that each element is completely isolated by LOCOS (Local Oxidation of Silicon) oxide film from other devices in the lateral direction. The operating element areas are completely isolated by insulators. As the buried oxide film 820 isolates transistors from substrate 810 , a distribution area of a current induced by a magnetic field is shallower compared to the conventional vertical Hall sensors in CMOS devices. Accordingly, a Hall sensor that is built using SOI CMOS techniques according to the present invention has a higher sensitivity.
[0039] In the exemplary embodiment shown in FIG. 8, the Hall sensor is a vertical Hall sensor that senses a magnetic field parallel to the surface of the wafer surface. It is appreciated, however, that other Hall sensor configurations can also be implemented, including the following horizontal Hall sensors that detect magnetic field vertical to the surface of semiconductor: island isolated sensors, PN junction isolated sensors and gated island isolated sensors, all of which are fabricated integrally with the SOI CMOS and described in more detail later herein.
[0040] With reference to FIG. 7, the four areas marked with reference number 71 are gated regions of the vertical sensors that are Si island isolated, and those marked with reference number 73 are sensing areas of the lateral sensor where the current has a strong vertical component which is necessary for detection of the horizontal magnetic field. Due to the structure of a SOI CMOS, the isolation between the four gated regions is typically achieved either by a Silicon island (which is typical for SOI CMOS) separated by a trench filled with oxide, or a traditional PN junction. Trenches filled with oxide or traditional PN junctions are shown in FIG. 10 (marked by reference number 77 ). FIG. 10 is a cross-sectional view of FIGS. 14-17 through line 10 - 10 . The active sensing areas 73 may be either implanted n-type (for example) high voltage FET implantation or inversion layer MOSFET (gated sensor) or both. The layout of FIG. 7 also shows bias points 75 on a side of the gated regions 71 for supplying a bias voltage to the gated regions 71 .
[0041] Reference is again made to FIG. 8. As a general rule, SOI CMOS devices comprises a Si supporting substrate 810 and buried oxide film 820 . Also, these devices are structured such that each element of the device is completely isolated by a LOCOS oxide layer such that SOI active layers are completely isolated by insulators. LOCOS isolation may be replaced by pn junction isolation as required. In the exemplary embodiment of FIG. 8, gated vertical Hall sensor 80 includes two dual gate transistors 830 and 840 built on a low doped, n-type island. Each of the dual gate transistors 830 and 840 includes a first gate 831 and 841 and a second gate 832 and 842 . The first and second gates 831 , 841 and 832 , 842 correspond to gated regions 71 of FIG. 7. A supply voltage terminal 850 located between these two dual transistors 830 and 840 supplies an input voltage (e.g., 5V) to a drain or source (not identified) of the transistors 830 and 840 which are close to the supply terminal 850 . A source or drain of the transistor 830 and 840 at a far end from the supply terminal 850 are grounded, as shown by grounded terminals 880 and 890 . It is noted that the two dual gate transistors 830 and 840 are symmetrical with each other and the polarities of these transistors can be chosen based on the specific application. Hall voltages VH+ and VH− can be sensed at terminals 860 and 870 located between first and second gates 831 and 832 of transistor 830 , and between first and second gates 841 and 842 of transistor 840 , respectively as shown in FIG. 7 and FIG. 8.
[0042] In one experiment, a horizontal magnetic field Hs up to 200 Oe parallel to the long side of the gate regions 71 (i.e., in the direction oriented into the paper for FIG. 8) was applied to the sensor 80 with a current strap (not shown) just above the sensor. FIG. 9 is a current distribution diagram of the Hall sensor of FIG. 8. In operation, supply terminal 850 supplies a supply voltage (e.g., 5V) to Hall sensor 80 . In the presence of the bias, a current is induced at the junction of the supply voltage and carriers of the current tend to travel from the supply terminal 850 to grounded terminals 880 and 890 through channels under the gates 831 , 832 , 841 and 842 . To guarantee a smooth traveling of the carriers, in accordance with a preferred embodiment, gates 831 , 832 , 841 and 842 are biased by bias voltages so that the gate regions or channels are slightly depleted to allow the carriers traveling deep in channels under the gates 831 , 832 , 841 , and 842 . Applying the magnetic field directed into the page of FIG. 9 creates a positive change of the channel region potential under gate 841 and a negative change of the channel potential under gate 831 . The potential change leads to a change of the voltage between the gates and channel and therefore increases the current in the 831 and decreases the current flowing under the gate 841 . Since the higher current causes larger Hall voltage, there is positive feedback created in the device 840 and negative feedback in the device 830 . This leads to a decrease in the potential of terminal 860 and an increase in the terminal 870 . Accordingly, consistent with small-signal amplification theory, a small change in channel region potential (due to the presence of the magnetic field) generates a continuous and significant output voltage between terminals 860 and 870 . Because of the amplification, the Hall voltages sensed at terminals 860 and 870 is significantly increased. As a result, the sensitivity of the Hall sensor 80 is increased.
[0043] [0043]FIGS. 11-13 are relationship curves showing sensitivity versus bias voltages and differential Hall voltages versus bias current and bias voltage that represent experimental data obtained from a gated vertical Hall sensor configured in accordance with the present invention as depicted in FIGS. 7, 8 and 9 .
[0044] [0044]FIG. 11 shows a relationship curve between the bias voltage and the sensitivity in a measured magnetic field up to 200 Oe. FIG. 11 shows that the sensor has high sensitivity for a bias voltage above 3V and a gate voltage of 4V and 7V. The sensitivity is about equal for the two directions of magnetic field under this bias conditions.
[0045] [0045]FIG. 12 shows relationship curves of bias current of the Hall sensor versus bias voltage and the differential Hall voltage versus the bias voltage, in which the gate voltage is 4V. The resistive character of the curve indicates that both the dual gate transistors 830 and 840 are operating in a linear region. The differential Hall voltage is shown for three values of write current (i.e., 0 mA, 840 mA and −840 mA) in a write strap 26μ×1 micron that is positioned about 1 micron above the sensor. Further, an offset voltage is over 70 mV for this bias situation.
[0046] [0046]FIG. 13 shows relationship curves of bias current of the Hall sensor versus bias voltage and the differential Hall voltage versus the bias voltage, in which the gate voltage is 0V. Again, the differential Hall voltages is shown for the three values (i.e., 0 mV, 840 mV and −840 mA) of write current. The saturated character of the curve indicates that at least one dual gate transistor is depleted and the other transistor is slightly on and operating in the saturation mode. The Hall effect for the slightly on transistor thus disappears for one direction of the magnetic field for which the negative feedback action occurs. In FIG. 13, the sensor responds to the current (i.e., magnetic field) in a negative direction only. Further, in this bias situation, the offset voltage is over 100 mV.
[0047] From the experimental data shown in FIGS. 11-13, it can be seen that a Hall sensor in accordance with the present invention can not only detect a magnitude of a magnetic field, but can also detect a direction or orientation of the magnetic field. For example, from the curves of FIG. 13, the Hall sensor detects the magnetic field only in a negative direction.
[0048] Furthermore, the present invention appropriately controls the bias voltage so that a current change induced by a change of the effective gate bias voltage results in a significant influence on the Hall voltage. As a result, the sensitivity of the Hall sensor in accordance with the present invention is improved by a factor of ten over the conventional vertical Hall sensor integrated on a bulk CMOS, such as the sensor shown in FIG. 3. Experimental data shows that the constant voltage and constant current sensitivity according to the present invention and the conventional Hall sensor of FIG. 3 are of 1200 V/V*T versus 130 V/V*T and 200 mV/A*T versus 23 mV/A*T, respectively.
[0049] Although the preferred embodiment described above focuses on the structure of a vertical Hall sensor integrated with SOI CMOS devices, it should be appreciated that different configurations of horizontal Hall sensors can also be designed and manufactured consistent of the principles of the present invention. Such configurations may be lateral Hall sensors that detect the magnetic field perpendicular to the page in FIGS. 14-17. Those configurations may include island isolated sensors that may includes cross shaped sensors, as shown in FIG. 14, and diamond shaped sensors, as shown in FIG. 15. In addition to the island (LOCOS oxide isolated) isolated sensors, other configurations may include pn junction isolated sensors, as shown in FIG. 16, and gated island isolated sensors, as shown in FIG. 17. In each of these cases, two bias points are provided, one that corresponds to 850 and one that corresponds to the points 880 and 890 combined in 881 and two Hall sensing points 860 and 870 are provided. Each of the points is isolated either by silicon islands separated by a trench filled with oxide or traditional PN junctions from other points. The cross, island isolated sensor in FIG. 14 has voltage bias applied between points 850 and 881 . The resulting current flows parallel to the page and is deflected by a magnetic field applied perpendicularly to the page (also seen in FIG. 10). The deflection creates a differential voltage between point 870 and 860 . The shape and operation of this particular sensor is similar to standard Hall sensors, but here the sensor is built in a SOI fabrication process.
[0050] The diamond shaped, island isolated sensor in FIG. 15 has voltage bias applied between points 850 and 881 . The resulting current flows parallel to the page and is deflected by a magnetic field applied perpendicularly to the page (also seen in FIG. 10). The deflection creates a differential voltage between points 870 and 860 . Two sensors 80 are shown connected in such a way that the offset of one sensor is subtracted from the offset of the other, whereas the Hall voltages add up. While the shape and operation of this sensor is similar to standard Hall sensors, this sensor is built in a SOI fabrication process.
[0051] The diamond shaped, pn junction isolated sensor in FIG. 16 has voltage bias applied between points 850 and 881 . The resulting current flows parallel to the page and is deflected by a magnetic field applied perpendicularly to the page. The deflection creates a differential voltage between points 870 and 860 . The substrate potential may be controlled with terminal 844 to change bias current or sensor sensitivity. The shape and operation of the sensor is similar to standard Hall sensors, but here, again, the sensor is built in a SOI fabrication process and provides additional control of substrate potential.
[0052] The diamond shaped gated, island isolated sensor in FIG. 17 has voltage bias applied between points 850 and 881 . The resulting current flows parallel to the page and is deflected by a magnetic field applied perpendicularly to the page (also seen in FIG. 10). The deflection creates a differential voltage between point 870 and 860 . The bias and sensitivity of the sensor may be controlled with the substrate terminal 844 and the gate terminal 843 . As above, the shape and operation of the sensor is similar to standard Hall sensors, but here the sensor is built in a SOI fabrication process and provides additional control of gate and substrate potential.
[0053] The foregoing disclosure of the preferred embodiments of the present invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Many variations and modifications of the embodiments described herein will be apparent to one of ordinary skill in the art in light of the above disclosure. The scope of the invention is to be defined only by the claims appended hereto, and by their equivalents.
[0054] Further, in describing representative embodiments of the present invention, the specification may have presented the method and/or process of the present invention as a particular sequence of steps. However, to the extent that the method or process does not rely on the particular order of steps set forth herein, the method or process should not be limited to the particular sequence of steps described. As one of ordinary skill in the art would appreciate, other sequences of steps may be possible. Therefore, the particular order of the steps set forth in the specification should not be construed as limitations on the claims. In addition, the claims directed to the method and/or process of the present invention should not be limited to the performance of their steps in the order written, and one skilled in the art can readily appreciate that the sequences may be varied and still remain within the spirit and scope of the present invention.
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A magnetic sensor device formed using SOI CMOS techniques includes a substrate, a silicon oxide layer and in some cases a plurality of gated regions. A first terminal is located between two innermost gated regions and supplies a supply voltage. A second and a third terminal, each of which is located between two adjacent gated regions other than the two innermost gated regions, output positive and negative Hall voltages. By appropriately controlling a bias voltage to the gated regions, small changes in a magnetic field induces larger currents in channel regions under the gated regions, which, in turn, results in detectable Hall voltages.
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FIELD OF THE INVENTION
This invention relates to industrial vehicles such as forklift trucks, and more particularly, to a supporting structure for a fuel feeding gun being inserted in a fuel inlet to pour fuel into a fuel tank.
DESCRIPTION OF THE RELATED ART
A common process of feeding fuel into a fuel tank in the field of industrial vehicles such as forklift trucks is to feed fuel by the use of a fuel feeding gun as is the case of a popular vehicle, that is, it generally comprises the steps of inserting a barrel portion of the fuel feeding gun in the fuel inlet of the fuel tank and spouting fuel out of the barrel portion into the fuel tank. According to this general process of performing fuel feeding by the use of the fuel feeding gun, however, under the condition that the barrel portion of the fuel feeding gun is inserted in the fuel inlet, an inconvenience tends to occur that the fuel feeding gun will revolve or come off the fuel inlet during the process of fuel feeding owing to an imbalance in weight between the gun body portion and the barrel portion. In view of such an inconvenience, in many cases, the fuel inlet 10 is opened so as to face vertically above as shown in FIG. 5, or to have a slight inclination from the vertical line as shown in FIG. 6.
However, if the fuel inlet is opened so as to face vertically above or to have a slight inclination from the vertical line, although this measure can prevent revolution and coming off of the fuel feeding gun during the process of fuel feeding, there arises another inconvenience that the work of fuel feeding is difficult to perform.
SUMMARY OF THE INVENTION
It is the object of the present invention to provide a supporting structure for a fuel feeding gun in a fuel tank which is capable of preventing revolution and coming off of the fuel feeding gun to permit a fuel inlet to be opened with a desired inclination (a comparatively gentle inclination) to thereby allow smooth performance of the work of fuel feeding by the use of the fuel feeding gun.
To achieve the foregoing object, the present invention provides a supporting structure for a fuel feeding gun in a fuel tank, comprising a cylindrical retainer provided in a portion of the fuel tank in which a barrel portion of the fuel feeding gun is inserted, and a support member provided correspondingly to a base end upper portion of the retainer which projects into the fuel tank in parallel with the axial line of the retainer and supports the barrel portion of the fuel feeding gun when the barrel portion is in the inserted state in the retainer.
Other objects of the present invention will become apparent upon understanding the embodiment hereinafter described and will be indicated clearly in the appended claims. Various advantages not referred to herein will occur to those skilled in the art upon practicing the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view of a forklift truck equipped with a supporting structure for a fuel feeding gun according to the present invention;
FIG. 2 is an enlarged sectional view of a fuel tank portion as viewed from one side;
FIG. 3 is an enlarged sectional view of the fuel tank as viewed from the above;
FIG. 4 is a sectional view of the fuel tank portion under service; and
FIGS. 5 and 6 are side views of forklift trucks provided with individual fuel inlets according to the related art.
DESCRIPTION OF THE PREFERRED EMBODIMENT
A practical embodiment of the present invention will now be described with reference to the drawings.
In FIGS. 1 through 4, reference numeral 100 designates a truck body, and numeral 101 designates a lift mechanism mounted on the front portion of the truck body 100. In this truck body 100, numeral 1 designates a front wheel, numeral 2 designates a rear wheel, numeral 3 designates a chassis frame mounted on the front and rear wheels 1 and 2, numeral 4 designates a front protector, numeral 5 designates an engine hood, numeral 6 designates a driver's seat, and numeral 7 designates a head guard. On the chassis frame 3 and between side frames 3a and 3a there are mounted an engine, transmission case, clutch case and the like (not shown).
One side frame 3a has a fuel tank 8 attached on its inside and an indented section 9 formed on its outside at a position corresponding to the fuel tank 8 which serves also as a getting on/off step. The indented section 9 is formed by an erecting concave wall 9a and a peripheral wall 9b surrounding the concave wall 9a into a substantially rectangular shape, with the concave wall 9a having a fuel inlet 10 opened so as to communicate with the fuel tank 8. The fuel inlet 10 is made up of a cylindrical retainer 110 fixed on the outer surface of the concave wall 9a of the indented section 9 and a cap 210, with the retainer 110 erecting from the fuel tank 8 with an appropriate inclination, or a comparatively gentle inclination. A tip side opening portion 111 of the retainer 110 has a threaded portion and the cap 210 is detachably screwed on this threaded portion. The concave wall 9a has a support plate 12 for supporting a fuel feeding gun 13, which is attached to the inside surface (on the side of the fuel tank 8) so as to correspond to the opening portion (hereinafter referred to as a base side opening portion 11), on the side of the fuel tank 8, of the retainer 110. The support plate 12 consists of an attaching segment 12a to be fixed to the upper margin of the base side opening portion 11, an abutting segment 12b formed by bending the lower margin of the attaching segment 12a so as to extend toward the inside of the fuel tank 8, and a rising segment 12c formed by bending upward the tip margin of the abutting segment 12b, and is made into the form of a substantial "U". Further, the abutting segment 12b has the same inclination as that of the retainer 110. That is, this segment projects obliquely downward into the fuel tank 8 in parallel with the axial line of the retainer 110.
The action of the foregoing configuration will now be described.
In connection with the fuel inlet 10 provided projectingly in the indented section 9, remove the cap 210 from the retainer 110 and insert a barrel portion 13b of the fuel feeding gun 13 into the retainer 110 while supporting its body portion 13a. Further, pull a trigger while keeping the barrel portion 13b in the inserted state in the retainer 110, whereby fuel is spouted out from a nozzle portion formed in the tip portion of the barrel portion 13b, that is, the action of fuel feeding into the fuel tank 8 takes place. Then, under the condition that this fuel feeding action is taking place, the body portion 13a having been supported up to now is set free from an operator's hand. As a result, due to the action of an imbalance in weight between the side of the body portion 13a and the side of the barrel portion 13b, the fuel feeding gun 13 turns about the tip side opening portion 111 of the retainer 110, so that the side of the barrel portion 13b looks upward and hence the barrel portion 13b thus turned upward comes into abutment on the abutting segment 12b of the support plate 12. FIG. 4 illustrates the state wherein the barrel portion 13b is in abutment on the abutting segment 12b of the support plate 12. In this way, as the barrel portion 13b abuts on the abutting segment 12b, the fuel feeding gun 13 is held in the position just attained when it was inserted in the retainer 110, that is, there is obtained the effect that revolution and coming off of the fuel feeding gun 13 are prevented. For reference, it is possible to shorten in dimension the retainer 110 in proportion to the length of the support plate 12.
As described hereinabove, according to the present invention of the foregoing configuration, in connection with the fuel inlet 10 of the fuel tank 8, the retainer 110 projecting from the fuel tank 8 has the support plate 12 for the fuel feeding gun 13 attached to its base side opening portion 11 (on the side of the fuel tank), and by means of the action of an imbalance in weight arising between the body portion 13a and the barrel portion 13b of the fuel feeding gun 13, the barrel portion 13b of the fuel feeding gun 13 is caused to abut on the support plate 12, so that revolution and coming off of the fuel feeding gun 13 during the process of fuel feeding can effectively be prevented.
In addition, because revolution and coming off of the fuel feeding gun 13 are prevented as described above, the setting inclination of the retainer 110 can be made gently (or obtusely) as compared with the configuration of the related art, whereby it is possible to perform smoothly the work of fuel feeding.
Since it is apparent that many other modifications may be made without departing from the spirit and scope of the present invention, it is not intended to have the present invention limited to the specific embodiment thereof, except as defined in the appended claims.
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A supporting structure for a fuel feeding gun in a fuel tank is provided, comprising a cylindrical retainer provided in a portion of the fuel tank in which a barrel portion of the fuel feeding gun is inserted, and a support member provided correspondingly to a base end upper portion of the retainer which projects into the fuel tank in parallel with the axial line of the retainer and supports the barrel portion of the fuel feeding gun when the barrel portion is in the inserted state in the retainer.
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CROSS-REFERENCE TO RELATED APPLICATION
This application claims priority to copending U.S. provisional application entitled, “Systems and Methods for Controlling Characteristics of a Flame,” having Ser. No. 60/379,031, filed May 8, 2002, which is entirely incorporated herein by reference.
FIELD OF THE INVENTION
The present invention relates to apparatus and methods for controlling a flame.
BACKGROUND
Some fuels burned by oil lamps produce relatively large amounts of smoke, but are still in use because they have other beneficial properties. For example, citronella oil produces smoke but is useful for repelling insects, such as mosquitoes. Although a citronella lamp user can avoid the buildup of smoke by extinguishing the lamp and relighting it later, this is undesirable because it extinguishes the light source. Although the amount of light produced by citronella oil is less than other types of liquid fuels, it is nonetheless convenient to have this light source and many users find the pink colored flame to be attractive.
Air drafts around the flame tend to increase the amount of smoke produced, so some existing lamps provide a shield around the flame to protect from drafts. However, shielding the flame from drafts can result in an inadequate air supply to the flame. This inadequate air supply results in incomplete combustion, which also tends to increase the amount of smoke produced.
SUMMARY
The present invention is directed to unique methods and apparatus for controlling a flame. In one embodiment, independent control of the characteristics of an inner flame and an outer flame is provided by controlling the flow of fuel and air to the flames. The apparatus and method reduces smoke by providing a stable airflow to the flames, thus reducing the effect of air drifting over the flames. The outer flame also reduces smoke by burning soot particles produced by the inner flame, and by shielding the inner flame from outside air. These features are especially useful when the fuel is citronella oil, which produces a relatively smoky flame. However, these apparatuses and methods apply to various types of liquid fuel, and are not limited to any particular type of liquid fuel such as citronella.
The size of the inner and outer flames can be independently controlled by controlling the flow of air and fuel to the flames. In one embodiment, the inner flame can be extinguished by closing off the fuel supply, then can be reignited by reopening the fuel supply. Using different types of fuels for the two flames results in different colors for the inner and outer flames, which provides a visually appealing effect. For example, using citronella oil for the inner flame and liquid paraffin oil for the outer flame results in an inner flame which is of a generally pink color, and an outer flame which is of a generally yellow color. Color characteristics are further controlled by reducing the airflow between the inner and outer flames, which may provide a single flame with a blend of colors from the two fuels.
DESCRIPTION OF THE DRAWINGS
In the drawings, individual components of the apparatus are not necessarily drawn to scale, or with the same proportions.
FIG. 1 is a perspective view of an exemplary embodiment of an apparatus for controlling a flame.
FIG. 2 is a top sectional view of the apparatus of FIG. 1 .
FIG. 3 is a partial side cutaway view of the apparatus of FIG. 1 .
FIG. 4 is a partial front cutaway view of the apparatus of FIG. 1 .
FIG. 5 is a cutaway view of the fuel reservoir section of FIG. 1 .
FIG. 6 illustrates a wick holder which can be used in conjunction with an embodiment of an apparatus for controlling a flame.
FIG. 7 is a perspective view of another embodiment of an apparatus for controlling a flame.
DETAILED DESCRIPTION
FIG. 1 is a perspective view of an exemplary embodiment of an apparatus for controlling a flame. The apparatus includes: fuel reservoirs 102 and 103 ; caps 104 and 105 ; fuel valves 106 and 107 ; air containers 108 and 109 ; air valves 110 and 111 ; wicks 112 and 113 ; shield 114 ; and collar 115 .
The fuel reservoirs 102 , 103 contain liquid fuel, for example, liquid paraffin, mineral oil, citronella oil, or a variety of other suitable fuels. In one embodiment, the fuels contained in fuel reservoirs 102 , 103 are different, so that the color characteristics of the flames may be different. Caps 104 , 105 allow the fuel reservoirs 102 , 103 to be filled, and also seal to prevent air from entering fuel reservoirs 102 , 103 through the cap opening. In one embodiment, caps 104 , 105 are safety caps to prevent buildup of excess vapor pressure. Each fuel valve 106 , 107 is in fluid communication with one of the fuel reservoirs 102 , 103 , so that when fuel valve 106 , 107 is open, ambient air flows into fuel reservoir 102 , 103 .
Each fuel reservoir 102 , 103 is in liquid communication with one of the wicks 112 , 113 . The wicks 112 , 113 may be made of any suitable material, such as glass fiber or metal mesh, as long as the wick draws liquid fuel from the fuel reservoir.
Each air valve 110 , 111 is in fluid communication with an air container 108 , 109 , so that when air valve 110 , 111 is open, atmospheric air flows into air container 108 , 109 .
Air flows from air container 108 , 109 to the flame-bearing end of a corresponding wick 112 , 113 . Supplying air through a container provides a regulated and continuous flow of air to the flame, reducing the effect of any air currents or turbulence around the apparatus.
The exemplary embodiment may also include a shield 114 surrounding wicks 112 , 113 , and a collar 115 , which fastens shield 114 to the fuel reservoirs 102 , 103 and/or air containers 108 , 109 . Shield 114 acts to prevent a user from coming into direct contact with the flame, and also to prevent air drafts from affecting the flame. Shield 114 has an aperture 116 to allow exhaust gases to escape from the apparatus. The aperture of a conventional lamp must be relatively large in order to provide an adequate air supply to the flame, but aperture 116 can be relatively small because the apparatus supplies air to the vicinity of the flame through an air channel (see FIG. 2 ). A small aperture may be desired because it prevents air drafts from extinguishing the flame.
FIG. 2 is a top sectional view of the apparatus of FIG. 1 . In one embodiment, fuel reservoirs 102 and 103 and air containers 108 and 109 are separate pie-shaped pieces arranged to form a substantially circular base 101 . In an alternative embodiment, fuel reservoirs 102 and 103 and air containers 108 and 109 are instead portions of substantially circular base 101 , formed by separation walls 201 and 202 inside one-piece base 101 .
In this exemplary embodiment, wicks 112 , 113 (see FIG. 2 ) are concentrically disposed atop the base 101 at wick receiving areas 203 and 204 , respectively. The wicks can be made of, for example, a tubular form of cotton/glass fiber. A portion of each wick 112 , 113 is in fluid communication with fuel reservoirs 102 , 103 through openings 205 , 206 in fuel reservoirs 102 , 103 . Wick 112 is supplied with air from air container 108 , through opening 207 in air container 108 , which opens into air channel 208 in the hollow center of the first wick 112 . Wick 113 is supplied with air from air container 109 , through opening 209 in air container 109 , which opens to air channel 210 in the space between the inner and outer wicks 112 and 113 .
FIG. 3 is a partial side cutaway view of the apparatus of FIG. 1 . In this view, air containers 108 , 109 are visible, but fuel reservoirs 102 , 103 are not. Air channel 208 ( FIG. 2 ) has a first end 301 located near the flame-bearing end 302 of wick 112 , and a second end 303 located in air container 108 . Air channel 210 ( FIG. 2 ) has a first end 304 located near the flame-bearing end 305 of wick 113 , and a second end 306 located in air container 109 .
When air is allowed to flow freely through air channels 208 and 210 , each of the wicks 112 , 113 produces a distinct and separate flame at its flame-bearing ends 302 , 305 . Flames with different characteristics can be produced by using different fuels in fuel reservoirs 102 , 103 . One characteristic that varies with the type of fuel is the flame color: liquid paraffin produces a yellow flame; citronella oil produces pink; oil blended with copper salts produces green or blue; oil blended with lithium salts produces red. These flame colors can be manipulated by controlling the flow of air through air channels 208 and 210 .
When airflow through air channel 208 to center of wick 112 is reduced, the color of the flame on wicks 112 and 113 is unaffected, but the size of the flame on wick 112 is decreased. When airflow through air channel 210 to the area between wicks 112 and 113 is reduced, the inner flame on wick 112 is unaffected, but the outer flame on wick 113 migrates from the outer edge of the wick and begins to merge with the inner flame on wick 112 . As airflow through air channel 210 decreases further, the flame-bearing end 305 of wick stops burning, though the area in between wicks 112 and 113 still contains hot gases which are a product of fuels from both fuel reservoirs 102 , 103 . At this point, the inner flame on wick 112 is of a single color but the color of the merged flame in the area surrounding the inner flame is a blend of colors, a result of the mixture of fuels in this area.
In the embodiment illustrated in FIG. 3 , the airflow through air channels 208 and 210 is reduced using air valves 110 and 111 . However, other mechanisms may be used to control airflow.
FIG. 4 is a partial front cutaway view, of the apparatus of FIG. 1 . In this view, fuel reservoirs 102 , 103 are visible, but air containers 108 , 109 are not. A portion of wick 112 , comprising a second end 401 , extends into fuel reservoir 102 . Similarly, a portion of wick 113 , comprising second end 402 , extends into fuel reservoir 103 . Fuel valves 106 , 107 control the flow of air from the atmosphere into fuel reservoirs 102 , 103 .
The fuel flows generally as follows: wicks 112 , 113 utilize the surface tension of the liquid fuel to draw it up through the fibers of the wick by capillary action. When the wick 112 , 113 burns fuel at its flame bearing end 302 , 305 , an equal amount is drawn up the wick 112 , 113 from fuel reservoir 102 , 103 to replenish the burned fuel. In normal operation, fuel valves 106 , 107 are open, so that air flows from the atmosphere into fuel reservoir 102 , 103 to fill the void left by the burned fuel.
In another mode of operation, fuel valves 106 , 107 are closed so that air is unable to flow into fuel reservoir 102 , 103 to fill the void left by the burned fuel. In this mode, the internal pressure in fuel reservoir 102 , 103 is reduced as the fuel burns. This reduced internal pressure resists the capillary action of the wick. When the reduced internal pressure is great enough to overcome the capillary action, liquid fuel is no longer drawn up the wick 112 , 113 to replenish the burned fuel. At this point, the flame will diminish in size as the fuel already in the wick is burned, until that fuel runs out and the flame is finally extinguished. Thus, closing fuel valve 106 on fuel reservoir 102 will result in the flame of wick 112 being extinguished, while closing fuel valve 107 on fuel reservoir 103 will result in the flame of wick 113 being extinguished. If fuel valve 106 or 107 is reopened, then the corresponding wick will reignite after a period of time, unless both fuel valves 106 and 107 have been closed.
In the exemplary embodiment illustrated in FIG. 4 , the apparatus also includes wick sleeves 403 , 404 to carry wicks 112 , 113 . In one embodiment, the wick sleeves 403 , 404 are shaped to closely conform to the wicks 112 , 113 . Wick sleeves 403 , 404 prevent expansion of the flame to the lower part of the wicks 112 , 113 , and increase the capillary pressure on wicks 112 , 113 . Wick sleeves 403 , 404 may be made of a heat-conductive material, for example, copper or glass, to lower the viscosity of the liquid fuel. In one embodiment, the wick sleeves 403 , 404 are made of glass tubing and have an angled edge 405 at the end corresponding to the flame-bearing end 302 , 305 of the wick. This angled edge 405 aids in the insertion and removal of the wick 112 , 113 , and also reduces flow of liquid fuel down the side of wick sleeves 403 , 404 and into air containers 108 , 109 .
FIG. 5 is a cutaway view of the fuel reservoir section of FIG. 1 . The angle θ can be varied to produce reservoirs of various number and capacities. Wall 501 divides fuel reservoir 102 into a first portion 502 and a second portion 503 . The fuel reservoir 102 is fillable with liquid fuel through cap 104 , which is in fluid communication with first portion 502 . Fuel valve 106 , also in fluid communication with first portion 502 , controls the flow of air from the atmosphere into fuel reservoir 102 , as described with regard to FIG. 4 . At least one perforation 504 a-c in wall 501 allows fuel to communicate between first portion 502 and second portion 503 . The fuel end 401 of the wick 112 is located in second portion 503 , such that it makes contact with liquid fuel flowing into second portion 503 .
In the exemplary embodiment, first portion 502 is hollow, and second portion 503 is solid, except for at least one first channel 505 a-c and a second channel 506 connecting to first channels 505 a-c . Use of a solid central portion strengthens the base 101 (see FIG. 2 ). The open end 507 of second channel 506 lines up with opening 205 (see FIG. 2 ) in the base 101 .
First channels 505 a-c are aligned with perforations 504 a-c so that liquid fuel contained in first portion 502 flows through perforations 504 a-c into first channels 505 a-c , and from there flows into second channel 506 . Perforations 504 a-c provide an air-tight seal around first channels 505 a-c . The fuel end 401 of the wick 112 is located in second channel 506 such that it makes contact with liquid fuel flowing into second channel 506 . In this embodiment, first channels 505 a-c are substantially aligned along a horizontal axis and second channel 506 is substantially aligned along a vertical axis, but embodiments can include any alignment that allows the liquid fuel to flow from first portion 502 into second channel 506 .
FIG. 6 illustrates a wick holder 601 which can be used in conjunction with the fuel reservoir illustrated in FIG. 5 . In this embodiment, wick holder 601 fits into second channel 506 (see FIG. 5 ). Wick holder 601 is tubular, with an open end 602 which aligns with hole 205 (see FIG. 2 ) when placed in second channel 506 (see FIG. 5 ) and a closed end 603 . At least one slit 604 in wick holder 601 allows liquid fuel to flow from vertical channel 506 (see FIG. 5 ) into fuel end 401 (see FIG. 4 ) of wick 112 (see FIG. 4 ), and from there liquid fuel travels to flame bearing end 302 (see FIG. 4 ) via capillary action. Wick holder 601 can be made of any suitable material such as metal or glass.
FIG. 7 is a perspective view of another embodiment of an apparatus for controlling a flame. Inner wick 112 and outer wick 113 are concentrically arranged, with an air channel 210 disposed between them. An additional air channel 208 is disposed in the approximate center of the inner wick 112 . An inner wick sleeve 403 surrounds one surface of inner wick 112 . An outer wick sleeve 404 surrounds one surface of outer wick 113 . Fuel reservoirs 102 , 103 are in fluid communication wicks 112 and 113 .
In the example embodiment, the apparatus consists of several nested pieces. Wick sleeves 403 and 404 are substantially tubular in shape, and wicks 112 and 113 are shaped like hollow cylinders. Another tubular piece, air container 108 , is disposed between outer wick 112 and inner wick 113 , forming air channel 210 between the wall of air container 108 and the outer surface of inner wick 112 .
In the example embodiment, wick sleeves 403 , 404 and air container 108 are each of different lengths. The length of air container 108 is such that when air container is placed inside outer wick sleeve 404 and their tops are substantially aligned, a portion 701 of air container 108 extends through opening 702 in outer wick sleeve 404 . Similarly, the length of inner wick sleeve 403 is such that when inner wick sleeve 403 is placed inside air container 108 and their tops are substantially aligned, a portion 703 of inner wick sleeve 403 extends through opening 704 in air container 108 .
Fuel reservoirs 102 , 103 are in fluid communication with wick sleeves 403 , 404 . In the exemplary embodiment, fuel reservoirs 102 , 103 are an integrated part of wick sleeves 403 , 404 , but in another embodiment fuel reservoirs 102 and 103 are separate pieces connected to wick sleeves 403 , 404 . Caps 104 , 105 allow fuel reservoirs 102 , 103 to be filled.
In addition, threads 705 on the exemplary embodiment allow caps 104 , 105 to regulate the flow of air into fuel reservoirs 102 , 103 . When cap 104 , 105 is in a tightly closed position, the pressure inside fuel reservoir 102 , 103 is reduced as fuel is burned, and this reduced pressure resists the capillary action of wick 112 , 113 , so that finally the wick stops drawing fuel and the flame is extinguished. When cap 104 , 105 is not tightly closed, air flows into fuel reservoir 102 , 103 as fuel is burned so that pressure is not reduced and the capillary action of wick 112 , 113 continues. While threads 705 in cap 104 , 105 are used in the exemplary embodiment, any mechanism which regulates the flow of air into fuel reservoirs 102 , 103 could be used instead.
The foregoing description has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Obvious modifications or variations are possible in light of the above teachings. The embodiments discussed, however, were chosen and described to illustrate the principles of the invention and its practical application to thereby enable one of ordinary skill in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. All such modifications and variation are within the scope of the invention as determined by the appended claims when interpreted in accordance with the breadth to which they are fairly and legally entitled.
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An apparatus for producing a sustained flame, comprising: a first reservoir for containing a first flame-fueling liquid; a second reservoir for containing a second flame-fueling liquid; a first wick having a first end disposed within the first reservoir and a second, flame-bearing end generally located above the first end; a second wick disposed substantially adjacent to the first wick, having a first end disposed within the second reservoir and a second, flame-bearing end above the first end; and at least one air channel disposed to supply oxygen to each wick, where a first end of the at least one air channel is generally located near the flame-bearing end of each wick; whereby, when the first and second flame-fueling liquids are supplied to the first and second reservoirs, the first and second flame-fueling liquids are communicated up the first and second wicks to fuel flames emanating from the flame-bearing ends of the first and second wicks.
A method for controlling a flame comprising: controlling a first flow of air to a first flame; controlling a second flow of air to a second flame; wherein the first flame and the second flame are concentrically disposed.
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The United States Government has rights in this invention pursuant to Contract No. N00019-80-C-0017 awarded by the Department of the Navy.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to afterburning (augmented) gas turbine aircraft engines of the bypass type and, more particularly, to mixed flow augmented gas turbine engines suitable for efficiently powering aircraft at widely varying flight speeds by controlling the engine bypass flow to satisfy correspondingly different engine operating conditions.
2. Description of the Prior Art
In the course of the development of the gas turbine aircraft engine, at least two basic variations of such engines have evolved that are suitable for powering aircraft at speeds that approach or exceed Mach 1. The two variations are the turbojet and the turbofan.
In a turbojet engine, the engine's turbine section receives the combustion gases and extracts only the power required to drive the compressor and accessories necessary for continuous operation. The remaining power of the combustion gases is used to provide forward thrust by accelerating the gases through an exhaust nozzle and out the downstream end of the engine. The turbojet engine is particularly effective for developing the high thrust necessary for powering aircraft at speeds in excess of Mach 1.
In a turbofan engine, the turbine section extracts power from the combustion gases to drive the compressor and accessories and extracts additional power in order to drive a fan section that accelerates air to provide forward thrust for the aircraft. The air accelerated by the fan is called bypass air because it bypasses the engine core. The turbofan or bypass engine is best suited for powering aircraft at speeds approaching but not attaining Mach 1.
A great deal of effort has been directed at developing a gas turbine engine with the attributes of both a turbojet and a turbofan. Ideally, an engine would have the high specific thrust characteristics of a turbojet but could also be configured to exhibit the lower specific thrust, and better fuel consumption characteristics of a turbofan. This type of engine would be used in mixed-mission type aircraft.
Engines that are suitable for these mixed-missions have been developed in various forms with varying degrees of success. Low bypass turbofans of fixed geometry are in current production--and even more operative flexibility has been obtained with variable cycle/bypass engines in which the amount of air that is bypassed is changed to suit aircraft speed. Perhaps the greatest problem with many of the variable cycle engines to date is the added complexity, weight and cost required by the structures that provide the variable bypass feature.
Variable bypass systems have been considered for use in typical military engines that use augmentors (afterburners) to provide additional thrust at supersonic speeds. Afterburning turbofan engines typically utilize mixers that take part of the engine's bypass air and mix or inject that air into the core engine flow in an engine's afterburning section. This allows more of the total engine airflow to be utilized with the afterburner for maximum thrust potential and also permits the use of a single throat variable exhaust nozzle. In these afterburning engines a substantial portion of the bypass flow is devoted to augmentor and nozzle cooling. Experimentation has shown that variable cycle engines that vary the amount of bypass air injected at the afterburner region can obtain significant performance advantages. Typically, it is desirable to increase the total bypass flow at dry operating conditions and to reduce the bypass flow at augmented conditions. Under dry conditions the object is to improve specific fuel consumption and during augmented conditions the object is to improve thrust. Systems that inject the bypass air at the afterburner have been commonly referred to as rear Variable Area Bypass Injectors (rear VABI's). Some examples of such rear VABI's are described in various U.S. Patents including U.S. Pat. No. 4,069,661; U.S. Pat. No. 4,064,692; U.S. Pat. No. 4,072,008; and U.S. Pat. No. 4,068,471.
One particular version of these recently developed rear VABI's utilizes what as commonly referred to as a variable/drop chute type of mixer injector. The term "drop chute" is used because the system employs mixer chutes that are hinged to be "dropped" or deployed inwardly and outwardly relative to the core engine flow so the chutes can inject varying amounts of bypass flow into the core engine stream. Although this provides many of desired thermodynamic advantages, which permit gains in engine performance, the drop chute type of rear VABI can be a relatively heavy, complex design that is not readily adaptable into existing engine configurations.
OBJECT OF THE INVENTION
It is, therefore, an object of the present invention to provide an augmented, mixed flow, gas turbine engine with a system that can vary bypass airflow injection into the core engine flow and, additionally, can be incorporated into existing augmented turbofan engine configurations.
It is another object of the present invention to provide an augmented mixed flow gas turbine engine that incorporates a rear variable area bypass injector (rear VABI) that can simultaneously vary the proportions of bypass air that is injected into core engine flow at a position upstream of the afterburning section and, additionally, at a position in the afterburning section itself.
It is another object of the present invention to provide an augmented mixed flow gas turbine engine with a system that is capable of increasing the injection of bypass flow into the core engine flow, downstream of an augmentor flameholder, for lower pressure losses under those conditions where it is desirable to increase the bypass ratio.
It is another object of the present invention to provide an augmented mixed flow gas turbine engine with a system that is capable of varying the injection of bypass flow through a mixer into core engine flow upstream of the afterburning section while simultaneously varying the injection of bypass flow into the core engine flow at a position in the afterburning section and additionally will vary a flow of bypass air into an exhaust nozzle cooling liner.
SUMMARY OF THE INVENTION
These and other objects of the invention are achieved in an embodiment of the invention wherein a gas turbine, bypass engine is provided with a rear Variable Area Bypass Injector (VABI) system that incorporates a sliding valve configuration to vary the amount of bypass flow injected into an afterburning section to improve engine performance.
In one embodiment of this unique VABI system, all of the bypass air is directed into one of three separate paths. In a first path, a major portion of the bypass air is directed into a fixed geometry daisy mixer just upstream of the afterburning section of the engine. This daisy mixer injects the bypass air directly into a core engine stream in the plane of the engine's augmentor flameholders so that this bypass air is available for combustion in the afterburner section. It is generally desirable to maximize this flow during supersonic aircraft operation when the afterburner is in operation.
That portion of the bypass air that is not directed into the mixer is directed into an annular passage that circumferentially surrounds the afterburning section of the engine. A plurality of air admission slots is circumferentially distributed in this annular passage at a region just downstream of the augmentor's flameholders. A valve is provided that slides axially to cover and uncover these air slots and thereby modulate a second flow of bypass air that flows through the slots and enters the core engine stream downstream of the augmentor flameholders.
The axial movement of the sliding valve also cooperates with a liner valve to additionally control a third flow of bypass air into an exhaust nozzle cooling liner that surrounds the engine exhaust region through the full downstream portion of the afterburning section.
With this configuration, the rear VABI of this invention can be arranged to direct a majority of the bypass air through the daisy mixer and into the core engine flow before it enters the afterburning section. This type of mixing of bypass flow is desirable when the afterburners are burning fuel and require large amounts of air to support the combustion. On the other hand, the slide valve can be rearranged to uncover the slots so that bypass air can flow through these slots effectively increasing the rear cross sectional area of the bypass duct and thereby lessening flow path restrictions on the bypass flow. A less restricted bypass flow is highly desirable during non-afterburning (dry) operation such as subsonic cruising. An intermediate position of the slide valve will keep the air slots closed, yet completely open the entry into the exhaust nozzle liner. This can be highly desirable to keep the nozzle liner cooled at certain times during afterburning operation while still directing most of the bypass flow through the mixer into the afterburners.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention may be better understood upon reading the following description of a preferred embodiment in conjunction with the accompanying drawings wherein:
FIG. 1 is a cross-sectional view of an augmented, mixed flow, gas turbine engine incorporating variable bypass injection mixing concepts of the present invention;
FIG. 2 is a perspective view of a prior art, Variable Area Bypass Injector (VABI);
FIG. 3 is an enlarged perspective view of a portion of the gas turbine engine of FIG. 1 that incorporates one embodiment of the present invention;
FIG. 4 is an enlarged cross-sectional view of the present invention and certain portions of the gas turbine engine of FIG. 1;
FIG. 5 is an enlarged perspective view of an embodiment of the present invention as shown in FIG. 3, but in a different operational mode;
FIG. 6 is a cross-sectional view of the VABI of the present invention in a "nominal" mode of operation;
FIG. 7 is a cross-sectional view of the VABI of the present invention in a "closed" mode of operation; and
FIG. 8 is a cross-sectional view of the VABI of the present invention in an "open" mode of operation.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIG. 1, there is shown a mixed flow gas turbine engine 10 having an outer casing 12 spaced apart from and surrounding an inner core engine 14. A passage or annular bypass duct 16 is formed between the casing 12 and the core engine 14. The mixed flow engine 10 has an inlet 17 that includes a fan section 18 that receives and pressurizes an inlet airflow, a portion of which is directed into the core engine 14 and the remainder of which is directed into the bypass duct 16. The core engine includes a compressor 20 that further compresses the inlet airflow and discharges highly compressed air into a combustor 22. In the combustor 22, fuel is burned in the highly compressed air to provide high energy combustion gases that drive a high pressure (HP) turbine 24. The HP turbine 24 operates to extract energy from the high energy combustion gases through the use of rotating turbine blades 25. The HP turbine 24 converts this extracted energy into shaft horsepower for driving the compressor 20.
Disposed downstream of the HP turbine, in a position to receive the flow of hot gases leaving the HP turbine 24, is a low pressure (LP)turbine 26, so-named because the combustion gases have dropped in pressure somewhat after some of their energy has been extracted by the HP turbine. Additional energy is extracted from the combustion gases by the LP turbine, again for conversion into shaft horsepower, but this time to drive the fan section 18.
From the LP turbine 26, the core engine combustion gases flow into an engine exhaust region 28. Just downstream of the LP turbine 26, a daisy mixer 30 is located in an interface region between the engine exhaust region 28 and the bypass duct 16. This mixer 30 functions to channel bypass airflow from the bypass duct 16 directly into the core engine stream after the core engine stream is exhausted from the HP and LP turbines. A daisy-type mixer is well suited for this mixing function because it will direct one gas flow into another gas flow stream in an efficient manner with generally low pressure losses.
Downstream of both the mixer 30 and the core engine 14, fuel injector spraybars 32 are provided in an afterburning section 33 to carburate the core engine exhaust flow during augmented (afterburning) engine operation. This injected fuel ignites and burns at flameholders 34 and flows at high velocities through the exhaust region 28 and out an engine exhaust nozzle 35.
Those skilled in the art of jet engine design have realized that it can be desirable to vary the manner in which the bypass flow is mixed with the core engine stream. For example, when the afterburning section 33 is operating, it can be advantageous to direct all of the bypass flow into the core engine stream so that all of the oxygen in the bypass flow is available to the augmentors during combustion. When the engine's flameholders 34 are not ignited, it can be desirable to increase the bypass flow and inject a portion of that flow at a location downstream of the flameholders 34 and thereby decrease mixing losses.
For these and other reasons, experimentation with variable cycle engine concept demonstrators has shown gains above those obtained with fixed mixers by using a rear mixer that is variable in its discharge area. Such variable mixers have been described as rear Variable Area Bypass Injectors (rear VABI's).
Referring now to FIG. 2, one prior art form of a rear VABI 36 is shown mounted on a rear section of a bypass type engine that is similar to the engine shown in FIG. 1. This rear VABI 36 is referred to as a "drop chute" type rear VABI. The name "drop chute" is used because this VABI has multiple movable chutes 38 that are "dropped" radially inwardly to directly inject bypass flow into the core engine stream. The chutes are hinged so they can be "dropped" to varying degrees by a series of actuators 40. By varying the degree or angle to which the chutes are "dropped", the discharge area of the augmentor mixer is thereby varied to suit engine operational conditions.
While the "drop chute" rear VABI shown in FIG. 2 does attain certain very desirable thermodynamic advantages, actual assemblies can be somewhat heavy, complex and also can be relatively expensive due to the large number of moving parts, linkages and actuators.
Referring now to FIG. 3, one embodiment of the present invention is shown mounted on a rear section of the bypass-type engine that is shown in FIG. 1. Both the drop chute mixer shown in FIG. 2 and the present invention shown in FIG. 3 are capable of varying mixing area. As stated earlier the drop chute mixer 36 does this by dropping the chutes 38 further into the core engine stream. The present invention, which will be referred to as variable slot VABI 42, changes the mixing area by axially translating a cylindrical sleeve valve 44 to vary the area of outlet means from an annular passage 41 that circumscribes the exhaust region 28 of the engine. A disadvantage of the drop chute VABI 36 is that the individual chutes must be projected directly into the core engine stream. This type of projection requires linkage and unison ring hardware to integrate the individual chutes. Additionally the core engine exhaust forces on these projected chutes are a significant consideration and the drop chute system must be made sufficiently strong to withstand the core engine stream pressure forces. In contrast, by using the translating sleeve valve 44, the present invention variable slot VABI 42 inherently requires lower actuating forces and relatively lighter components due to lower metal and air friction forces.
Referring now to FIG. 4, the variable slot VABI 42 is shown in relation to an engine's exhaust region 28 and afterburning section 33. The flameholders 34 in conjunction with the fuel injecting spraybars 32 largely make up the augmentor combustion system. There are shown in FIG. 4 a circumferential array of fixed daisy mixer chutes 30. These mixer chutes 30 are located at a downstream end of the bypass duct 16 of the engine and at a leading edge of an augmentor cooling liner 48. This location can be described as an interface region between the bypass duct and the core engine stream. The mixers 30 direct a majority of the bypass flow directly into the core engine flow stream at a location upstream of the flameholders 34 so the bypass flow can provide oxygen to the augmentor when it is operating. These fixed mixers are normally used in conventional turbofan augmentors.
An outlet means to the annular passage 41 is shown in the form of ports or air admission slots 46 located upstream of the cooling liner 48. The individual slots 46 are positioned directly downstream of, and in alignment with, each of individual chutes of the daisy mixer 30.
In FIG. 4, the cylindrical sleeve valve 44 is shown in a "closed" position meaning that the sleeve closes off the slots 46 and prevents bypass air from flowing through the slots. This forces a majority of the bypass flow to pass through the daisy mixer 30 and effectively lessens the rear bypass mixing area.
It can also be appreciated from FIG. 4 that a downstream end of the sleeve valve 44 includes a circumferential flange 50 that cooperates with an exhaust casing projection 52 to limit the flow of bypass air through a liner passage 54 thereby forming a liner valve 53 between the cooling liner 48 and exhaust casing 62. In the arrangement of the variable slot VABI 42 shown in FIG. 4, the slots 46 are completely closed off as stated above, and additionally, the area of the cooling liner passage 54 is in a "minimum" configuration. This is the same arrangement of the VABI 42 that is shown in FIG. 3, meaning again, the slots 46 are closed off and the area of the passage 54 is "minimum." This configuration creates a minimum rear mixer area, for lowest bypass flow, and highest engine specific thrust.
Referring now to FIG. 5, the variable slot VABI 42 is shown in a configuration wherein the sleeve valve 44 has been translated downstream in relation to engine airflow to "open" the slots 46. This permits the engine's bypass flow to pass through both the daisy mixer 30 and the slots 46, in tandem, effectively increasing the rear mixer area. The sleeve 44 comprises a circumferentially disposed scoop 66 that directs the bypass flow into the outlet means in the annular passage 41. It is to be noted that in this position the liner cooling valve 53 from FIG. 4 is also fully opened.
To accomplish this translation, the sleeve valve 44 is moved axially with a system that uses the valve 44 itself as a synchronizing ring. To move the valve 44, the single actuator 40 extends and retracts an arm 56 that pivotally attaches to a rotating crank 58. Extension and retraction of the arm 56 causes the crank 58 to rotate which, in turn, causes cylinder arm 60 to swing through an arc. The cylinder arm 60 is pivotally connected to the sleeve valve 44 so that the swinging action of the arm causes the sleeve to move axially and circumferentially in a helical path between the cooling liner 48 and engine exhaust casing 62. This helical pattern provides the aforementioned synchronizing action which allows only one actuator to accomplish the required motion. It can be visualized that if the cylinder 58 did not rotate in conjunction with axial translation, that it would cock and bind. In addition to the actuator 40 and crank 58, two or more pivots 64 are provided around the circumference of the sleeve valve 44. The pivots 64 connect the sleeve valve 44 to the exhaust casing 62 at spaced positions to facilitate the axial and circumferential (helical) motion of the sleeve valve 44 during its translational movement.
Referring back to FIG. 3 the actuator arm 56 in this Figure is extended outwardly. Outward extension of the actuator arm 56 places the sleeve valve 44 in a forward position thereby "closing" the slots 46.
By contrast, in FIG. 5, the actuator arm 56 has been retracted causing the sleeve valve 44 to translate to a rear or downstream position in respect to engine airflow thereby "opening" the slots 46. It can be readily appreciated that because the cylinder arm 60 swings through an arc some circumferential or helical motion of the sleeve valve 44 always accompanies the axial motion of that sleeve valve. The sleeve valve is supported inside the exhaust casing 62 with pivots 64 that are mounted circumferentially around the perimeter of the exhaust casing 62 which center the valve with respect to the casing. The circumferential movement of the sleeve valve 44 forces the pivots 64 to move in unison. This uniform movement causes the sleeve valve 44 to retain a self-synchronizing feature that, together with inherently low actuation forces, allows the use of a single actuator to translate the sleeve valve 44. The circumferential motion of the valve 44 does not influence the aerodynamic operation of the VABI 42, in that all the aerodynamic aspects of the valve are symmetrical in the axial direction.
OPERATIONAL DESCRIPTION
The foregoing description of the invention has been directed to the mechanical configuration and mechanical operation of the variable slot VABI 42. It is now appropriate to describe the use of the VABI 42 in relation to different modes of operation of the engine and the aircraft.
Referring again to FIG. 1, the position and relationship of the variable slot VABI 42 to the overall engine 10 can be readily appreciated. As stated earlier, the rear VABI will vary the mixing area where bypass airflow from the bypass duct 16 actually mixes with the core engine flow in the engine's exhaust region 28. Engine cycle studies show that gains in engine thrust can be achieved at conditions of maximum power dry combat and maximum acceleration with augmention (afterburning) by using a rear VABI to alter the mixing area. In addition, specific fuel consumption can be improved with a rear VABI at part power cruise and loiter operation of the aircraft. These improvements are in relation to a typical fixed area rear mixer engine (nominal) where the rear mixer area is fixed but the area has been chosen so as to provide reasonably good engine performance over the full range of engine operational modes. This nominal case must necessarily be a compromise and is simply improved upon by operation of a rear VABI.
An equivalent of the nominal case is achieved when the sleeve valve 44 of the variable slot VABI 42 is brought to an intermediate position. Referring now to FIG. 6 the desired position of the sleeve valve 44 is shown in relation to the engine's exhaust cooling liner 48, exhaust casing 62 and associated components. In this intermediate or "nominal" position the sleeve valve 44 has effectively closed the slots 46 so the bypass air cannot flow through these slots. At the same time, the axial position of the sleeve valve 44 is such the circumferential flange 50 of the sleeve valve is positioned somewhat downstream of the exhaust casing projection 52, thereby opening the liner passage 54. This nominal position decreases the mixing area from maximum but still permits a flow of bypass air through the liner passage 54 to cool the engine's exhaust cooling liner 48. This nominal position can be highly desirable during certain operational modes including maximum afterburning operation at low flight speeds to cool the liner downstream of the augmentors.
In order to obtain objective thrust improvement gains during supersonic afterburning conditions, the VABI 42 is closed from the nominal case to reduce the bypass ratio and improve the specific thrust. At least part of the reason for doing this is that a natural result of turbofan engine operation is the bypass ratio tends to increase with flight speed. To maintain or decrease the bypass ratio the appropriate position of the sleeve valve 44 for closing the VABI 42 is shown in FIG. 7. The valve 44 has been translated axially forward or upstream so as to close both the slots 46 and the liner passage 54. This valve position effectively decreases the mixing area which will tend to decrease the volume of engine bypass flow through the bypass duct. The closed valve position also causes a majority of the reduced level of bypass flow to enter the daisy mixers 30 and be directed into the core engine inlet thereby reducing the bypass ratio. This ensures that the oxygen in the bypass flow is available for combustion during afterburner operation. It is to be noted that the closed position is obtained by a simple additional translation of the valve from the nominal position.
In order to make objective gains at part power loiter and cruise conditions and at dry military power (IRP) combat condition, the VABI is opened from the nominal fixed case to increase the bypass ratio. Referring now to FIG. 8 the desired position of the sleeve valve 44 is shown for an "open" mixer area. An entry air scoop 66 of the sleeve valve 44 is positioned over the slots 46 to direct a portion of bypass airflow through the slots and into the core engine stream. That portion of the bypass flow that is not redirected by the scoops 66 is allowed to flow through the liner passage 54 and, eventually, out the exhaust nozzle of the engine. In this position additional core stream mixing of bypass flow is accomplished to improve thermal and pressure uniformity, hence propulsive efficiency, of the engine. This occurs because the air flowing through slots 46 is in direct alignment with and augments the fixed mixer air.
With this engine structure and method of operation, the variable slot VABI achieves many of the desirable objectives of previously conceived VABI's but does not require the large, complex structures of some of these previous designs. Simplicity, lighter weight, and smaller size can be significant advantages in the field of aircraft engines where size, weight, and cost are major factors in aircraft performance and affordability.
Although a specific embodiment of this invention has been illustrated and described, it is to be understood that various modifications could be made without departing from the spirit and scope of the invention. What is desired to be secured by Letters Patent of the United States is claimed below:
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An afterburning, gas turbine aircraft engine with an annular duct for carrying bypass airflow is provided with a sliding valve type of rear Variable Area Bypass Injector (VABI) system. This rear VABI varies the direction and volume of the flow of bypass air into separate regions at an afterburning section of the engine. The system includes a sliding valve mounted in the bypass duct that is translated axially to open and close slots leading to core engine exhaust flow in the afterburning section. The unique structure of the injector system enables the axial translation of this sliding valve to simultaneously control bypass airflow into: first, a mixer just upstream of the afterburning section; second, a plurality of slots leading to the afterburning section; and third, an exhaust nozzle cooling liner that is cooled with the remaining portion of the bypass air. The system is actuated with a mechanical design that uses both rotation and translation to simplify the actuation motion so that one actuator can translate the valve. Because the system employs a valve that translates over a plurality of slots, it is commonly referred to as a variable slot bypass injector.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention relates to a method for detecting a degree of wetting of a glass pane, in particular a windscreen of a motor vehicle, where electromagnetic waves are emitted by a transmitter arranged on the inside relative to the glass pane, which are reflected according to the total reflection principle on the outer, from the transmitter's point of view the opposite surface of the glass pane, and which are received by a receiver arranged on the inside of the pane. Furthermore the invention relates to a sensor unit for detecting a degree of wetting of a glass pane, in particular a windscreen of a motor vehicle, with a transmitter arranged on the inside relative to the glass pane, which emits electromagnetic waves reflected according to the total reflection principle on the outer, from the transmitter's point of view the opposite surface of the pane, and with a receiver arranged on the inside relative to the pane, which receives the reflected electromagnetic waves.
[0003] 2. Brief Discussion of the Related Art
[0004] Sensor units of this kind are known. Sensor means working according to the principle of total reflection are, for example, described in the DE 40 06 174 C1, the DE 197 46 351 A1, the DE 103 39 696 B4 and the DE 35 32 199 A1.
[0005] Apart from sensor units working according to the total reflection principle there are sensor units which operate with scattered light. Here electromagnetic waves are directed at as steep an angle as possible at the windscreen and penetrate the windscreen and are scattered on droplets, ice or other particles in front of the windscreen. The electromagnetic waves thus scattered are then received by a receiver arranged on the inside relative to the windscreen. Based on this evaluation conclusions can also be drawn as to the degree of wetting of the windscreen. Such a sensor unit has been described, for example, in the US 2011/0128543 A1.
[0006] Furthermore capacitive measuring methods are feasible, with which the degree of wetting of a glass pane may be measured. Such capacitive measuring methods have, for example, been described in the DE 10 2007 035 905 A1 and the EP 1 306 276 B1.
[0007] A generic publication is also known from the DE 103 11 800 A1. Further comparatively similar methods and devices are known from the DE 195 30 289 A1 and the DE 10 2004 047 215 A1.
SUMMARY OF THE INVENTION
[0008] The invention is based on the requirement to propose a method and a sensor unit of the kind mentioned in the beginning with which a particularly accurate and reliable detection of the degree of wetting of a glass pane is possible.
[0009] With a method for the detection of a degree of wetting of a glass pane, in particular a windscreen of a motor vehicle, comprising a transmitter arranged on the inside relative to a glass pane and emitting electromagnetic waves reflected according to the total reflection principle at the outer, from the transmitter's point of view the opposite surface of the glass pane, and which are received by a receiver arranged on the inside relative to the pane, provision is made furthermore, according to the invention, for electromagnetic waves to be emitted by a transmitter, which pass through the glass pane and are scattered on particles or drops in front of the glass pane and are received by a receiver, wherein the receiver is arranged between the transmitter operating according to the total reflection principle and the transmitter for scattered light measuring, and there receives the electromagnetic waves. Furthermore receipt of the electromagnetic waves by the receiver is effected close to the transmitter for scattered light measuring and at a distance more than twice as large to the transmitter which operates according to the total reflection principle.
[0010] According to the invention two different measuring methods are thus combined. This allows particularly good results to be achieved. For measurements with the total reflection principle it is possible to particularly well detect normal smaller droplets on the windscreen. For measurements with the scattered light principle it is possible to particularly well detect large amounts of water or sheets of ice which have accumulated on the glass pane.
[0011] Evaluation and determination of the degree of wetting of the glass pane is based on the results of both measuring methods, thus leading to an overall result with which the degree of wetting of a glass pane with rain and water droplets is particularly well detected.
[0012] With a preferred development of the method only a single receiver is used, which on the one hand receives electromagnetic waves reflected according to the total reflection principle and the other, receives electromagnetic waves reflected according to the scattered light principle. To this end a circuit is provided which switches between two different modes so that one and the same receiver on the one hand, receives measurements according to the total reflection principle and on the other, receives measurements according to the scattered light principle, followed by a respective evaluation. Preferably transmission of the electromagnetic waves of the two measuring principles is thus carried out alternately. In a first time period an electromagnetic wave, reflected according to the total reflection principle, is emitted by a transmitter, and in a second time period an electromagnetic wave reflected according to the scattered light principle is emitted by a transmitter. In this way it is ensured that the one or more receivers receive light reflected according to only one principle, thereby permitting an unequivocal evaluation to be effected. With an operation, where both measuring principles are run in parallel with two separate transmitters and two separate receivers, it is possible to either operate the transmitters alternately, or preferably to effect an optical separation so that it is ensured that each receiver receives only the electromagnetic waves emitted from its associated transmitter. Then the two transmitters and receivers can operate continuously.
[0013] In another preferred further development of the method provision is made additionally for capacitive measuring in order to detect the degree of wetting of a glass pane. Preferably the results of the two/three measuring principles are then evaluated in a single microcontroller. From the result thus obtained a signal for wiper control is derived. Information for the light and headlight settings can also be derived.
[0014] A further aspect of the invention consists in providing a sensor unit for the detection of a degree of wetting of a glass pane, in particular a windscreen of a motor vehicle, with a transmitter arranged on the inside relative to a glass pane, which is suited and configured to emit electromagnetic waves which are reflected according to the total reflection principle at the outer, from the transmitter's point of view the opposite surface of the glass pane, and with a receiver arranged on the inside relative to the pane, which receives the reflected electromagnetic waves. Such a sensor unit is characterised according to the invention in that this comprises a transmitter arranged on the inside relative to the pane, which is suited and configured to emit electromagnetic waves which pass through the pane and are scattered on particles in front of the pane, and which comprises a receiver arranged on the inside relative to a glass pane, which receives the scattered electromagnetic waves. The receiver is arranged between the transmitter which operates according to the total reflection principle and the transmitter for scattered light measuring. Further, the distance between the receiver and the transmitter which operates according to the total reflection principle, is more than twice as large as the distance between the receiver and the transmitter for scattered light measuring.
[0015] In this way a sensor unit is provided which is suited and configured with its respective transmitters and receivers, for measuring on the one hand, the degree of wetting on the surface of the glass pane according to the total reflection principle and on the other, for measuring the degree of wetting on the surface according to the scattered light principle. In particular droplet-shaped rain and droplet-shaped moisture can be particularly well measured with the transmitter and receiver which for transmitting and receiving the electromagnetic waves operate according to the total reflection principle. Layers of ice or completely closed moisture films or water films, i.e. a degree of wetting of 100%, can be particularly well detected according to the principle of scattered light detection.
[0016] In a particularly preferred embodiment of the invention the receiver for receiving the totally reflected electromagnetic waves is the same receiver which receives the scattered electromagnetic waves. In particular therefore this embodiment comprises one receiver and two separate transmitters, wherein those electromagnetic waves scattered on the outer side of the pane according to the total reflection principle, are emitted from one of them, and those electromagnetic waves incident at almost right angles on the pane and passing through it, are emitted from the other. To this end an evaluation circuit is preferably provided, which coordinates the transmitters and switches them alternately so that at a certain point in time the receiver receives only reflected or non-scattered electromagnetic radiation from respectively one transmitter, and the evaluation circuit detects from which one of the transmitters the received light is received at the receiver.
[0017] In a preferred development of the invention the sensor unit comprises an optics on the inside of the pane for bunching the electromagnetic waves scattered according to the total reflection principle.
[0018] Within the sensor unit the distance between the transmitter operating according to the total reflection principle and the receiver is larger, in particular more than twice as large and in particular three times as large as the distance between the transmitter operating according to the scattered light principle and the associated receiver.
[0019] In another preferred further development of the invention the sensor unit additionally comprises a capacitive sensor with which the degree of wetting is measured. Such a capacitive sensor comprises two electrically conducting surfaces which form the surfaces of a capacitor. The capacitance of the thus formed capacitor changes as a result of moisture on the glass pane and from the change in capacitance conclusions can be drawn in turn regarding the moisture.
[0020] Preferably the scattered light sensor, the total reflection sensor and the transmitter are accommodated within a common housing. It is favourable if provision is made for a wall inside the housing, which prevents that light coming from the transmitter for the total reflection directly reaches the receiver. Two optics are provided in the housing to take these measurements according to the total reflection principle. The wall is preferably arranged between these two optics.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] The invention will now be explained in more detail by way of an exemplary embodiment shown in the drawing, in which
[0022] FIG. 1 shows a schematic illustration of a first embodiment of the invention;
[0023] FIG. 2 shows a schematic illustration of a second embodiment of the invention; and
[0024] FIG. 3 shows a further embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0025] FIG. 1 shows a first embodiment of the invention, where a device 1 for detecting a degree of wetting of a glass pane 2 is schematically illustrated. The device 1 is arranged on the inside relative to the glass pane 2 , in particular a windscreen. Sensor units 1 of this kind are typically arranged on the glass pane 2 in the interior of motor vehicles. A first transmitter 3 is provided and configured for scattered light measuring and emits electromagnetic waves 13 for taking scattered light measurements. These are directed at the glass pane 2 at a comparatively steep angle and penetrate the same. The electromagnetic waves 13 are reflected from droplets 11 in the outside area of the glass pane 2 . This outside area may also be characterised as an area, in which the sensor unit 1 with the transmitter 3 is arranged, which lies opposite the inside area or the area in which the sensor unit 1 with the transmitter 3 is arranged. The electromagnetic waves 13 reflected from the water droplets 11 are then received by a receiver 4 for scattered light measuring. The receiver 4 is provided and configured for receiving the reflected waves 13 after taking scattered light measurements. The radiation thus received and the signal thus obtained in the receiver 4 is evaluated by a microcontroller 15 . The signal thus evaluated is used, for example in a wiper control 16 . Furthermore a second transmitter 5 is provided in the sensor unit 1 , which is configured for the emission of electromagnetic waves 12 which are totally reflected from the outer surface of the glass pane 2 and which are then received by an associated receiver 6 which is provided and configured for receiving electromagnetic waves 12 after total reflexion. If there exist water droplets 10 on the top of the glass pane 2 in the area of the totally reflected electromagnetic waves 12 , part of the electromagnetic waves 12 is decoupled, and the intensity received by the receiver 6 decreases. In the embodiment illustrated here, the receiver 4 for scattered light measuring and the receiver 6 for taking measurements after total reflection are constructionally combined in a single receiver. The two transmitters 3 and 5 are switched alternately by the microcontroller 15 so that the receiver 4 , 6 alternates between receiving the electromagnetic waves 13 emitted by the transmitter 3 and the electromagnetic waves 12 emitted by the transmitter 5 . The electric signal generated in the receiver 4 is passed to the microcontroller 15 for further evaluation. The microcontroller 15 evaluates the electric signals of receiver 4 as a function of whether these are based on the electromagnetic waves emitted from the transmitter 3 or from the transmitter 5 . From the obtained information a total information is ascertained which is used as a basis for activating the wiper control 16 . Information may also be derived which is used for controlling the air conditioning or the lighting. Further a capacitive sensor 7 is provided in the sensor unit 1 of FIG. 1 , which essentially comprises two capacitor surfaces 8 and 9 arranged on the inside of the glass pane 2 . Field lines 14 form between these capacitor surfaces 8 and 9 . The capacitance of the capacitor thus formed is also dependent on whether or not there are water droplets 10 on the glass pane 2 . From the resulting change in capacitance conclusions can then be drawn on the presence of water. The measured results of the capacitive sensor 7 are also passed to the microcontroller 15 and evaluated there.
[0026] FIG. 2 shows a second embodiment of the invention. Here the sensor unit 1 comprises three separate sensors, i.e. the scattered light sensor 22 , the total reflection sensor 23 and the capacitive sensor 7 . The scattered light sensor 22 here comprises a transmitter 3 for scattered light measuring and a receiver 4 for scattered light measuring. The transmitter 3 transmits the electromagnetic waves 13 which penetrate through the glass pane 2 . These are directed comparatively steeply at the glass pane 2 , so that this does not produce total reflection. The electromagnetic waves 13 are scattered on water droplets 11 , in particular those which are still at a certain distance from the glass pane 2 . Scattering and reflection also takes place on the water droplets 10 still adhering to the glass pane 2 . The electromagnetic waves 13 which are scattered back are received by the receiver 4 . In deviation from the embodiment as per FIG. 1 the total reflection sensor 23 here is configured with a transmitter 5 and its own receiver 6 . Here too a capacitive sensor 7 is provided which again comprises capacitor surfaces 8 and 9 . In particular with the total reflection sensor 23 the existence of a water film 21 , such as indicated here, cannot be unequivocally identified. Precisely for such borderline situations the use of several sensors in a sensor unit 1 is favourable because it allows the strengths of the different sensors to be combined. The measured results of the capacitive sensor 7 , the scattered light sensor 22 and the total reflection sensor 23 are evaluated in a microcontroller 15 . The measurements taken by individual sensors are combined to form an overall result and this is used as a basis for operating the wiper control 16 .
[0027] FIG. 3 shows a concrete embodiment of a sensor unit 1 . In this sensor unit 1 a scattered light sensor 22 and a total reflection sensor 23 are constructionally combined. Within a common housing 24 , a transmitter 3 , in particular a LED, is arranged on the floor of the housing 24 and thus at a distance from the glass pane 2 . In comparative proximity to the transmitter 3 a receiver 4 is arranged also on the floor of the housing 24 , which receives the scattered electromagnetic waves. In front of the glass pane 2 a sensitive area 20 is drawn, which indicates that not only water and other particles are detected directly on the glass pane 2 , but also in a certain area in front of the same. A total reflection sensor 23 with a transmitter 5 is arranged in the housing 24 . The transmitter 5 is also configured as a LED and is arranged on the floor of the housing 24 . The transmitters 3 and 4 are arranged at opposite end areas of the housing 24 . The transmitter 5 has an optics 17 assigned to it which is arranged on the ceiling of the housing 24 , which again is directly facing the glass pane 2 . In this way the light or the electromagnetic radiation coming from the transmitter 5 , in particular in the infrared range, is focussed and directed at the glass pane 2 at a comparatively flat angle so that as a result, total reflection is obtained on the outer side of the glass pane 2 which faces the external environment. If in this area water and other particles are present on the glass pane 2 , a part of that is decoupled, total reflection is not achieved and only a smaller part of the electromagnetic waves is reflected. A sensitive area 20 here is marked with 20 . This indicates that the sensitive area 20 here is distinctly flatter than the other sensitive area 20 which is created during scattered light measuring. A further optics 18 , which is assigned to a receiver 6 , is also arranged on the ceiling of the housing 24 and focusses the totally reflected electromagnetic wave in direction of the receiver 6 . This receiver 6 is, in this case, identical to the receiver 4 for scattered light measuring. The receiver 4 , 6 alternates between detecting light emitted by the transmitter 3 from scattered light measuring and detecting light emitted by the transmitter 5 for measuring according to the total reflection principle. Furthermore a wall 25 is provided in the housing 24 , which is arranged between the optics and 18 and which prevents light from the transmitter 5 reaching the receiver 6 by the direct route. The distance between the receiver 4 , 6 and the transmitter 3 is distinctly smaller than the distance between the receiver 4 , 6 and the transmitter 5 .
[0028] All features named in the above description and the claims can be selectively randomly combined with the features of the independent claim. The disclosure of the invention is therefore not limited to the described/claimed feature combinations, rather all feature combinations meaningful in terms of the invention are to be considered as disclosed.
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A method for detecting a degree of wetting of a glass pane, in particular a windscreen of a motor vehicle, is provided. A transmitter is arranged on the inside relative to a glass pane and emits electromagnetic waves, which are reflected according to the total reflection principle on the outer, from the transmitter's point of view the opposite surface of the glass pane, and which are received by a receiver arranged on the inside relative to the glass pane. Electromagnetic waves are emitted further from a transmitter. Waves pass through the glass pane and are scattered on particles or droplets in front of the glass pane and are received by a receiver arranged on the inside relative to the glass pane.
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BACKGROUND OF INVENTION
This invention relates to the use of a universally adjustable, hip mounted holster for pistol type power tools and similarly shaped objects.
This holster easily and securely holds a wide variety of shapes now utilized in the manufacture of drills, portable drills, screwguns, and portable screwguns. Two locations on the holster allow for proper adjustment to pistol type objects through the use of hook and pile material commonly known as "Velcro".
Holsters currently available are shaped to accommodate pistol shaped objects that narrow in size in approach towards the tip or use end. This holster not only accommodates such traditionally shaped pistol type objects, but also accommodates pistol shaped objects which widen in approach towards its tip or use end.
Most currently available holsters are designed to accommodate a particular pistol shaped object or a class of pistol shaped objects of approximately the same size and balance point as it hangs in a pouch on a loop wrapped around a belt. This holster is designed with an extra wide double loop arrangement that allows for the proper balancing of pistol type objects with radically different shapes, weights, and handles; from short and light to long and heavy. Many rechargable power tools contain battery packs within an extended heavy handle.
Two methods of affixing hip holsters to users belts prevail in the current state of art. One method utilizes a single loop, either fixed or with detachable fasteners on one end, through which the users belt passes. The other method employs slots in a piece of sheet material, most often leather, through which a belt passes thereby compressing a portion of the sheet material against the users body.
While both methods keep the holster somewhat stationary along the users belt line, neither method forces the holster to stay in the originally placed position.
The holster herein submitted employs a double loop method. By trapping or leaving free the users pants belt loop between holster loops, the user has an option as to a fixed or mobil location of holster along belt line. This arrangement represents an improvement in ability to affix the holster in a single location as the users pants belt loop would have to giveway before the holster would shift.
Other holsters with adjustable features have utilized the advantages of "Velcro". Referring now to U.S. Pat. No. 4,645,103, "Velcro" was incorporated to allow for adjustment in both the holster belt loop and weapon hold down strap. Neither of these adjustments have an affect on the size of the holster pocket. My invention allows for two or more adjustments along the vertical length of the holster pocket to accommodate a hitherto unrealized versatility in size and shape of pistol type object to be holstered.
Another holster, U.S. Pat. No. 4,312,466 is both adjustable and utilizes "Velcro". Its adjustability is limited to increased resistance to undesirable movement of holster safety strap.
Adjustable holster, U.S. Pat. No. 4,544,089 is adjustable in that it creates a belt width of tension across the center of weight of a variety of pistol type weapons as its tip or muzzel end points generally downward. The holster proposed in this application creates a continuously adjustable pocket. This pocket is approximately an elliptical cone and may be adjusted so that either end of the cone may be larger in circumference.
The design of this holster, combined with the synthetic materials of preferred embodiment allow for the production of an extremely strong, tear resistant, easily cleaned, no-rot, nonabsorbent holster. Additionally, this holster folds flat while not in use for easy storage and efficient use of tool storage space.
The owner of holster herein described may own numerous and varied pistol type power tools and other such objects and holster them all with this one apparatus.
OBJECTS AND ADVANTAGES
Accordingly the objects and advantages of my invention are numerous. This holster accommodates an exceptionally diverse variety of pistol type objects with a wide range of weights, shapes, sizes and centers of balance. The "Velcro" style adjustable straps employed here are easy to operate, affix in a secure manner and are part of a design which permits continuous adjustment along the vertical length of the holster pocket, thereby controlling the size of the generally elliptical cone that constitutes said pocket.
Both conventionally shaped pistol type objects which narrow in approach towards use end and unconventionally shaped pistols which widen in approach towards use end may be securely holstered.
Three simultaneous advantages of the extra wide double loop arrangement employed here are apparent. This extra wide double loop serves to balance the weight of pistol type objects with unconventionally long, heavy handles.
Secondly, the width of these loops taken together, when forced against the users waist by a belt, serve, in conjunction with a boning material entrapped in the upper seam of the holster sheet material, to constantly create an oval like opening at any given point along the adjustability range of the upper adjustable strap that is advantageous to easy pistol insertion.
Lastly, the double loop allows the user a choice between trapping users pants belt loop between holster belt loops, thus giving the holster a fixed location along the users belt line, or leaving the users belt loop free, thus allowing the holster to be shifted along users belt line at will.
This holster allows the owner to have and to holster a wide variety of pistol type objects without obtaining a seperate holster for each pistol, without the additional expense of additional holsters, and without the annoyance and waste of time incurred when shifting from the use of one power tool to another when utilizing more traditional holsters.
While not in use, this holster folds flat for easy and efficient storage.
The preferred embodiment of this invention results in numerous advantageous characteristics. The synthetic materials preferred are rot free, non-absorbent, have great strength, durability, tear resistance and are very inexpensive.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a flat view of the outside surface of the holster; the outside surface being that surface which remains visible once a pistol type object is secured in the holster.
FIG. 2 is a flat view of the inside surface of the holster; the inside surface being that surface which is not generally visible once a pistol type object is secured in holster.
FIG. 3 is a side evaluation view of the top seam of the holster demonstrating boning material affixed within the top seam. The top seam is depicted in FIG. 2 as running from point A to point B.
FIG. 4 is a view of holster hanging from wearer's belt, holding a small, portable screwgun.
FIG. 5 is a view of the holster hanging from wearer's belt, holding a large, portable drill with a long handle.
FIG. 6 is a view of the holster hanging from wearer's belt, holding a large heavy, corded power drill.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to component 1 as shown in FIG. 1, this material is flexible sheet material. The preferred embodiment of this component is vinyl nylon laminate as is commonly used in awning and tarp construction though other materials may be used. The preferred embodiment material is inexpensive and extremely resistant to tear. Sheet material utilized shall be cut to size appropriate for the range of adjustability desired to holster pistol type objects in a particular class of size.
The upper seam of this sheet material is folded down towards the inside of the holster and sewn or otherwise affixed, in such a manner as to entrap a band of boning material commonly used to retain the shape of collars in womens clothing, or other such material with the properties of shape retention and flexibility. The inside surface of the holster is that surface depicted in FIG. 2. The entrapment of boning material within the top seam is easily viewed in FIG. 3.
The boning material is sewn, or otherwise affixed, to both sides of the entrapping sheet material in one location 8 approximately at the center of the length of boning as is seen in FIG. 1.
The belt loops of this holster 2 and 3 are a flexible webbing material. The preferred embodiment of this component is nylon webbing. Nylon webbing has great strength, durability and resists damage from the level and quality of friction encountered on a belt loop, though other webbing material may be used.
These belt loops adjoin in placement on the sheet material at a point approximately in the center of the total length of the top seam; that distance being the same as the length of boning.
Belt loop webbing 2 is sewn, sewn and glued, or otherwise affixed, to sheet material at approximately a right angle to the top seam entrapping boning.
Belt loop webbing 2 covers an area on and above the sheet material from approximately the bottom edge of the holster to a point sufficiently above the top seam so as to allow for the width of belts that would be expected to hold a holster, whereupon, a 180 degree turn in the direction of the material is made. Said loop webbing extends down the inside surface of the sheet material to a point sufficiently below the top seam so as to allow for adequate attachment to sheet material.
Belt loop webbing 3 adjoins, or approximately adjoins, belt loop webbing 2 in placement on sheet material. Loop webbing 3 covers an area on and above the sheet material from a point on the outside surface of the sheet material sufficiently below the top seam so as to allow for adequate attachment to sheet material, to a point sufficiently above the top seam so as to allow for the width of belts that would be expected to hold a holster, whereupon a 180 degree turn in the direction of the webbing is made. Said loop webbing extends down the inside surface of the sheet material to a point sufficiently below the top seam so as to allow for adequate attachment to sheet material.
Referring now to component 6 as shown in FIG. 1; this material is pile fabric commonly known as "Velcro". This fabric is sewn, sewn and glued, or otherwise affixed to the sheet material from the vertical edge adjoining point A, as seen in FIG. 1, horizontally to a point approximately to the inside edge of belt loop webbing 2. The vertical area covered by this fabric extends from a point just below the top seam to a point slightly more than half the distance from the bottom of the top seam to the bottom of the sheet material.
Referring now to component 4 as shown in FIG. 1; this material is narrow webbing serving here as part of the upper adjustable strap. The preferred embodiment of this component is nylon webbing. However, other webbing or strapping material may be used.
This upper adjustable strap webbing is sewn, sewn and glued, or otherwise affixed to the sheet material along the upper edge of the upper adjustment flap 9 and extends beyond the sheet material of said flap a distance adequate to allow the hook material on the inside surface of the adjustable strap, to hold the strap in place while retaining a pistol type object. This strap is placed at approximately a 25 degree angle to the top seam entrapping the boning. Other angles may be used.
Referring now to component 5 as shown in FIG. 1; this material is also narrow webbing, serving here as part of the lower adjustable strap. The preferred embodiment of this component is narrow nylon webbing. Other webbing or strapping material may be used.
The lower adjustable strap webbing 5 is sewn, sewn and glued, or otherwise affixed to the sheet material in the center of the lower adjustment flap 10 and is approximately parallel to the upper adjustable strap. This strap extends beyond the sheet material of the lower adjustment flap a distance adequate to allow the hook material on the inside surface of the strap to hold the strap in place while retaining a pistol type object.
Referring now to component 11 as seen in FIG. 2; this material is hook fabric and is sewn, sewn and glued, or otherwise affixed, to that portion of upper adjustable strap 4 that extends beyond the sheet material and faces the inside of the holster.
Referring now to component 13, as seen in FIG. 2; this material is hook fabric material and is sewn, sewn and glued, or otherwise affixed to the lower inside portion of the upper adjustment flap 9, approximately at the end of the flap.
Referring now to component 12, as seen in FIG. 2; this material is hook fabric and is sewn, sewn and glued, or otherwise affixed, to that portion of the lower adjustable strap 5 that extends beyond the sheet material and faces the inside of the holster.
Referring now to component 15, as seen in FIG. 2; this material is nylon webbing, or other similar material, and is sewn, sewn and glued, or otherwise affixed to both sheet material and lower adjustable strap 5 so as to provide reinforcement to said strap.
USE OF HOLSTER
The double belt loop feature incorporated in this holster allows the user to either trap a belt loop of pants worn during use of holster, between belt loops of holster, thus giving the holster a fixed location along the users waist or to leave the users pants loop free of holster belt loops, thus allowing the holster to shift along users waist line at will.
The holster is hung from the users belt with the adjustable straps extending towards the back of the users body. At this time the holster is in a flattened condition. The surface facing away from the users body is the surface viewed in FIG. 2 and is referred to in this text as the inside surface.
The user then places desired pistol type object against the central portion of sheet material with the tip or use end of the object pointing in a downward direction. The user then folds the foward extending portion of sheet material, with pile fabric 6 affixed, around the housing of the pistol and holds said sheet material in place with their hand from the opposite side of their body than the holster is mounted.
User then, with their free hand, wraps upper adjustable strap 4 around the pistol and forces the hook fabric on said strap against the upper portion of pile fabric 6 approximately parallel to the upper edge of pile fabric. Said strap is placed in such a manner as to loosely conform to the shape of the outside surface of the trigger area of the pistol so as to allow for ease of pistol removal and insertion.
User then wraps lower adjustment flap 10 around the lower housing of pistol type object in such a snug manner as to conform to the peculiar shape of said pistol and forces the hook fabric of lower adjustable strap 5 against pile fabric 6.
FIG. 4 demonstrates the holstering of a small, portable screwgun. The housing of this gun progressively widens from its trigger area to the end of the housing whereupon a narrow driver protrudes from the housing. The lower adjustment flap 10 is properly placed to securely holster this unconventionally shaped pistol type object.
FIG. 5 demonstrates clearly the holstering of a long, heavy handled portable drill. The holster pocket is here set to accommodate a drill housing that narrows in stages approaching the chuck end of the drill.
Referring now to FIG. 6, the holster pocket is now shaped to accommodate a large, heavy, corded power drill; the housing of which remains uniform in width until the chuck end of the tool.
To holster a large pistol type object constructed in such a manner that the housing expands continuously from its trigger area to its use end, the user simply adjusts the lower adjustable strap 10 to create an internal pocket circumference sufficiently small to disallow the use end to pass through lower opening of holster. The upper adjustable strap 4 is then placed in such a manner as to securely retain pistol.
In this usage, the internal shape of the holster pocket is approximately an elliptical cone in which the circumference of the lower circle is larger than that of the upper circle. The boning material 7 entrapped in top seam of sheet material exerts a widening force so as to make the upper opening of the holster generally round. This boning material is affixed in one location approximately at the center of the top seam and travels slightly within the top seam as the top seam is wrapped around the pistol type object.
While the boning material works to keep the upper opening generally round, the compression of double loops 2 and 3 against the users body by worn belt, creates an ultimately oval like shape. This shape is conducive to easy removal and insertion of pistol type object.
Pistol type object may then be removed and re-inserted continuously without re-adjustment for the great majority of pistols that use a holster pocket which narrows towards the lower end of its elliptical cone. Holster is then so adjusted as to allow user to engage in generally vigorous activity without loss of pistol from holster.
This pistol type object will remain balanced in holster as a consequence of the presence of double belt loops 2 and 3.
Holster claimed may also secure handgun firearms.
Use of heat resistant materials in construction of holster would allow for the holstering of heatguns. Towards this end a stiff bracket, acting as a spacer, may be affixed horizontally or vertically across that portion of the holster that contacts the leg or hip of user.
Additional costruction materials may be added to sheet material to create small pouches and hold down devices to allow for the storage of pistol type object attachments to enhance use of pistol.
The sheet material may be cut to allow for holster to hang from either side of the body.
Additional adjustable straps on sheet material may be utilized while continuing to create a holster pocket that is shaped approximately as an elliptical cone.
Adjustable straps with mechanical fasteners used exclusively or in combination with "Velcro" type fasteners may be used. These mechanical fasteners may allow for discrete or continuous adjustment settings.
CONCLUSION, RAMIFICATIONS AND SCOPE OF INVENTION
Thus it is apparent that holster disclosed herein has exceptional versatility with regard to size, shape and weight of pistol to be holstered. The preferred embodiment is strong, durable and inexpensive.
My above detailed description contains many specifications, yet should not be understood as limitations on the scope of the invention. Many other embodiments are possible. For example, a tool or device much larger than would normally be termed a pistol type object may be secured in a holstering device that while essentially the same holster described herein, utilizes additional flaps and straps to secure said object within an adjustable elliptical cone.
An additional strap over the top of the holster may be employed to more firmly secure pistol type object for activity that is more than generally vigorous.
REFERENCE NUMERALS FOR FIGURES
1. Flexible Sheet Material
2. Belt Loop Webbing A
3. Belt Loop Webbing B
4. Upper Adjustable Strap Webbing
5. Lower Adjustable Strap Webbing
6. Pile Fabric
7. Boning Material
8. Single Boning Fastener
9. Upper Adjustment Flap
10. Lower Adjustment Flap
11. Upper Adjustable Strap Hook Material
12. Lower Adjustable Strap Hook Material
13. Upper Adjustment Flap Hook Material
14. Sheet Material Edge
15. Lower Adjustable Strap Webbing Reinforcement
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This invention is a universally adjustable holster that accommodates a wide variety of pistol shaped objects both conventionally and unconventionally shaped, including pistol type objects that enlarge from the trigger area to the use end. Two adjustable straps 4 and 5 along the vertical length of the holster pocket allow for the secure holstering of power drills, screwguns, and other pistol type objects. This holster can be produced with qualities of excellent strength and durablity at an extremely low cost. The condition of this holster when not in use is flat.
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BACKGROUND OF THE INVENTION
a) Field of the Invention
This invention relates to a new or improved variable ratio drive pulley. Such drive pulleys are widely used in belt drive transmissions for vehicles such as snowmobiles to provide both a clutch and a speed responsive variable drive ratio.
b) Description of the Prior Art
As used in snowmobiles, such drive pulleys are attached to the output shaft of the engine and comprise a fixed flange and a movable flange between which is engaged a transmission drive belt, the pulley containing weighted levers or the like which are influenced by the rotational speed of the pulley to displace the movable flange towards the fixed flange as the speed of rotation increases so that the radius at which the transmission belt is engaged between the flanges increases. Examples of such variable diameter drive pulleys can be seen in our Canadian Patents 985,931 and 1,208,040.
SUMMARY OF THE INVENTION
The present invention provides a variable ratio drive pulley comprising:
two opposed frusto-conical flanges arranged coaxially with respect to a drive shaft to rotate therewith and impart a variable ratio drive to a transmission belt arranged between the flanges;
one said flange comprising a fixed flange that is fixed axially relatively to said shaft, and the other said flange being a movable flange that is movable axially of said shaft so that the frusto-conical front face thereof moves towards and away from the confronting frusto-conical face of the fixed flange;
biasing means operatively arranged between said shaft and said movable flange to urge the latter axially away from said fixed flange;
centrifugally responsive thrust means operative upon rotation of said drive pulley to generate an axially directed thrust force acting to urge said movable flange towards said fixed flange, the magnitude of said thrust force increasing with the speed of rotation of said drive pulley;
said thrust means comprising a plurality of weighted levers equiangularly spaced about the axis of said shaft, and a corresponding plurality of cooperating ramps, each lever being pivotally mounted at one end in the movable flange and having its opposite end positioned to cooperate with a respective ramp that is carried in a part that is fixed with respect to said drive shaft, and
adjustment means accessible from the exterior of said drive pulley and operative to alter the attitude of said ramps and thus the dynamic response of said thrust means.
The ramps are preferably mounted in a carrier formed by a cup that is fixed to rotate with the shaft, the ramps being arranged in generally radial planes confronting the weighted levers that are pivotally mounted near the periphery of the movable flange. The cup has radial arms that cooperate with axially extending guide walls on the rear of the movable flange to constrain the movable flange to rotate with the shaft. Preferably the adjustment means is in the form of two diametrically opposed eccentric members carried in the cup to provide an adjustable abutment to support the rear of each ramp, adjustment of the abutment by angular adjustment of the eccentric members changing the attitudes of the associated ramps and thus the dynamic response of the drive pulley.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will further be described, by way of example only, with reference to the accompanying drawings wherein:
FIG. 1 is a side elevation of one embodiment of the variable ratio drive pulley in accordance with the invention;
FIG. 2 is a view in the direction of the arrows II--II in FIG. 1 and to a larger scale showing the drive pulley with the cover removed;
FIG. 3 is a sectional view taken on the line III--III in FIG. 2;
FIG. 4 is a perspective view corresponding to FIG. 2;
FIG. 5 is a perspective view corresponding to FIG. 4 but with the governor cup removed;
FIG. 6 is a perspective view of the governor cup taken from the side opposite that shown in FIG. 4; and
FIG. 7 is a perspective view of a preferred embodiment of the drive pulley in accordance with the present invention;
FIG. 8 is an axial view of a portion of the governor cup of the drive pulley of FIG. 7;
FIG. 9 is a sectional view taken on the line IX--IX in FIG. 8; and
FIG. 10 is a sectional view taken on the line X--X of FIG. 9.
DESCRIPTION OF THE PREFERRED EMBODIMENT
As seen in FIG. 1, a drive pulley for a snowmobile belt transmission is indicated generally by the numeral 10 and comprises a shaft 11 with a fixed flange 12 of frusto-conical shape and an opposed frusto-conical movable flange 13. The fixed flange 12 is axially and rotationally secured to the shaft whereas the movable flange 13 is displaceable in the axial direction towards and away from the fixed flange, although the movable flange is also constrained to rotate with the shaft 11. On its rear side the movable flange 13 has a short cylindrical peripheral wall 14 which is sized to be slid axially within a cylindrical cover 15. Upon displacement of the movable flange axially between the positions shown in full lines and in broken lines in FIG. 1. As best seen in FIG. 3, the shaft 11 passes through a bore 20 in the movable flange 13, this bore being expanded into an enlarged counterbore 21 defined by an annular wall structure 22 formed integrally in the movable flange 13. The bore 20 forms a close sliding fit with the shaft 11. As seen in FIG. 3, the shaft 11 defines a stepped shoulder 11a leading to a reduced diameter shaft section 11b having a splined end section 11c. The reduced diameter shaft section passes through an axial bore 24 of a cylindrical cap 25 that is attached to the wall 22 by threaded fasteners 26. The cap 25 and the wall 22 together define a generally annular chamber that surrounds the shaft section 11b and within which is positioned a coiled compression spring 27 one end of which presses against the grooved end 28 of the cap, and the other end of which presses against an annular seating element 29 positioned against the shoulder 11a.
As seen in FIGS. 2, 3 and 4, a governor cup assembly 33 is carried on the splined end 11c of the shaft and is fixed against axial and rotary movement with respect to the shaft.
As will be understood from the foregoing, the force of the compression spring 27 acts to press the seat element 29 against the shoulder 11a, and to press the cap 25 and movable flange 13 to the right as seen in FIG. 3, displacement of this assembly being limited by the cap end 28 coming into abutment with an annular seat 34 in the governor cup assembly 33.
The governor cup assembly 33 includes a pair of diametrically opposed drive arms 35 adapted to transmit rotary movement of the shaft to the movable flange 13 while still permitting axial movement therebetween. As seen in FIGS. 4 and 6, each arm 35 is in the form of a lug that projects radially outwardly and forwardly towards the rear side of the movable flange 13, and carries on its end a pair of oppositely directed slider elements 36 (which may be spring-loaded or fixed), these being of generally cylindrical form and having convexly curved outer ends. The end of each drive arm 35 is received between a pair of axially extending concavely curved walls 37 formed integrally with the movable flange 13 and projecting to the rear therefrom. Where the elements are spring-loaded the spacing between the walls 37 of each pair is slightly less than the spacing between the convex surfaces of the opposed slide elements 36, so that these must be compressed inwardly to be received between the walls 37. The elements 36 are made of any suitable low-friction material such as nylon. Alternatively, the elements 36 could be mounted on rubber seats (not shown) in the arms 35, the characteristics of the rubber being chosen to provide the necessary degree of resilience and in addition to provide damping. The walls 37 are positioned as close to the outer periphery of the movable flange 13 as is feasible to maximize torque transmission between the governor cup assembly 33 and the movable flange 13.
Centrifugal means are provided to effect displacement of the movable flange 13 from its fully retracted position as shown in FIG. 3 towards the left to the fully advanced position as shown in FIG. 1 against the force of the spring 27. These means comprise a pair of weighted levers 40 (see FIGS. 3 and 5) each of which is pivotally mounted on an axis 41 defined by a pivot pin carried in a pair of spaced walls 42 on the rear of the movable flange 13. Each lever 40 may be of any suitable construction, e.g. formed from pressed sheet metal or the like and extends generally inwardly away from the pivot axis 41 terminating in a low-friction roller 43 attached to the free end of the lever 40 by suitable fastener means 44. Weighting of the levers 40 may be achieved by any suitable means, and for example may be provided by the fastener means 44, together with washers or other selected masses.
Each weighted lever 40 is designed to cooperate with an adjustable ramp 50 that is carried in the governor cup assembly 33 and presented towards the associated lever 40. As best seen in FIGS. 3 and 6, the ramps 50 are in the form of flat steel plates having a convexly curved cam surface 51, and each being carried on a transverse pin 52 that is secured in recesses in the cup assembly 33 by fasteners 53 so that the ramp 50 is arranged in a radial plane with respect to the axis of the shaft 11 and can pivot to a limited extent about its pin 52. The location of the pin 52 will in practice be considerably closer to the axis of the shaft 11 than is illustrated in FIGS. 3 and 6, and of course can be varied as required in accordance with the overall design. The radially outer portion of the ramp 50 is supported by an abutment formed by the end of a stem 54 that is supported in the governor cup 33 behind the outer part of the ramp 50, as seen in FIGS. 3, 4 and 6. Each stem 54 extends parallel to the axis of the shaft 11 and passes through a cylindrical bore 55 in the governor cup 33. On the front face of the governor cup assembly surrounding the bore 55 there is an annular recess 57 in which are provided a series of seats 58 extending radially from the bore 55, these seats being arranged in diametrically opposed pairs, and each pair of seats being at a different axial location with respect to the bore 55. A transverse rod 60 extends through the forward end of the stem 54 and is adapted to cooperate with one or other of the pairs of seats 58 depending upon the angular position of the stem 54. The rod 60 is urged into engagement with the seats 58 by means of a compression spring 61 enclosing the stem 54 between its head and the rear surface of the governor cup assembly. Thus, to reposition the rod 60, the head of the stem 54 is engaged by a suitable tool, such as a screwdriver, (not shown) and the stem is advanced to compress the spring 61 and free the rod 60 whereupon the stem 54 can be rotated to align the rod with a selected pair of seats which it then engages when the stem 54 is released. As shown in FIG. 6, there are six pairs of seats 58 at angularly spaced positions, but a greater or lesser number can be provided as desired.
The end wall of the cover 15 that fits over and is attached to the rear of the governor cup assembly 33 has a large central opening to surround the central boss 32 and also has diametrically opposed circular openings to register with the stems 54 and allow unimpeded access to them and to the bores 55 and bore extensions 56 so that the stems 54 can be inserted and adjusted without any disassembly whatever of the pulley, since not even the cover 15 need be removed. The cover is secured by any suitable means, e.g. by a series of small screws extended through the end wall thereof and engaged in a corresponding series of threaded through holes 62 in the end wall of the governor cup assembly 33.
It will be appreciated that repositioning the rod 60 from one pair of seats 58 to another has the effect of axially adjusting the position of the abutment formed by the end of the stem 54, which, as will be seen from FIG. 3, will effect angular adjustment of the ramp 50 about its pin 52.
In operation, when the drive pulley is stationary or rotating at a low speed, the parts occupy the position as shown in FIG. 3 and the transmission belt 16 (FIG. 1) is not engaged between the flanges 12 and 13 and therefore is not driven. The movable flange 13 is held in this position by the force of the spring 27. As the rotational speed of the drive pulley increases, the centrifugal force acting on the weighted levers 40 tends to pivot these outwardly (counter clockwise as seen in FIG. 3) and this force produces an interaction between the rollers 43 and the cam surfaces 51 which generates an axial thrust on the movable flange 13 urging it towards the fixed flange 11. As the centrifugal force increases, this axial thrust becomes sufficient to overcome the force of the spring 27 and displace the movable flange 13 progressively closer to the fixed flange 12 until ultimately the position shown in full lines in FIG. 1 is reached. During this displacement of the movable flange 13, the transmission belt 16 is first engaged between the flanges at a radius adjacent the shaft 11, but as the speed increases the transmission belt is gradually forced to contact the flanges at an increasing radius. Also the peripheral wall 14 of the movable flange 13 becomes progressively more extended from within the cover 15 until the position shown in full lines in FIG. 1 is reached. The wall 14 is therefore telescopically arranged with respect to the cover 15.
It will be appreciated that the centrifugally generated thrust force acting on the movable flange 13 is a function of the geometry of the parts, and in particular of the relationship between the levers 40 and the shaped cam surface 51 of the ramps 50. The dynamic response of the pulley can be altered by varying these relationships, and this is the effect that is achieved by the adjustment means described in connection with the stems 54. By altering the axial position of the abutment formed by the end of a stem 54, a corresponding variation is made in the orientation of the cam surface 51 of the associated ramp 50.
The drive pulley as described above is of relatively simple low cost construction, and yet is extremely flexible in terms of its capacity to vary the dynamic response through the use of simple adjustment means without any need for disassembly of the components. Furthermore, if a greater range of adjustment is required than can be achieved simply through the stems 54, the drive pulley can be disassembled, the ramps 50 and/or the weighted arms 40 and/or the spring 27 being modified or replaced to provide the desired characteristics.
The embodiment shown in FIGS. 7 through 10 is basically similar to the one described above, but incorporates a number of refinements and improvements. Referring to FIG. 7, the drive pulley 10a comprises a fixed flange 12a and a movable flange 13a, but there is nothing equivalent to the cover 15 of FIG. 1, but rather the governor cup 33a is of more streamlined form having a smooth convexly curved end surface 38a. Apart from the absence of the cover 15, the embodiment of FIGS. 7 to 10 differs from the one earlier described chiefly in the arrangement and mounting of the slider elements 36a and the adjustment means for the ramps 50a.
As best seen in FIG. 8, the drive arms 35a of the governor cup 33a each carries a pair of transversely projecting registering studs 35b. Each slider element 36a is a plastic moulding formed with a bore 36b adapted to receive the stud 35b, and having in its outer periphery a groove 36c to receive a rubber ring 36d, as shown in the exploded illustration in FIG. 8 at the upper side of the arm 35a. As shown in the lower side of the drive arm 35a, in the installed condition, the ring 36 is located between the side wall of the drive arm 35a and the end of the slider element 36a to provide a resilient mounting for the latter.
The weighted levers 40a are shown only schematically in FIG. 9 and are not substantially different to those of the embodiment of FIGS. 1 to 6. Their rollers 43a as before cooperate with ramps 50a each of which carries a pin 52a on which it is pivotally adjustable, the pin being secured to the governor cup 33a by means of fasteners 53a. Each ramp 50a is arranged generally radially of the axis of the governor cup 33a, and passes between integral spaced parallel walls 65 which are spanned by a web 66 at their radially inner ends, and are likewise joined at their bases by a further transverse wall 67.
An adjustment mechanism 68 is mounted between the transverse walls 65 and comprises a threaded bolt 69 which passes through aligned bores 70 in the wall 65 and is clamped in position by a nut 71, the bolt passing through an adjustor element which is located between the walls 65. The adjustor element comprises a disc-shaped part 72 which is integral with an intermediate cylindrical eccentric 73 adjacent which is a coaxial hexagonal section 74. The eccentric 73 is aligned with and is engaged by the underside of the ramp 50a, as best seen in FIG. 10, whereas the hexagonal section 74 registers with an elongate slot 75 that opens from the outer end of the transverse wall 67. The disc section 72 has a series of sharp notches 76 spaced uniformly about its periphery, and is registered with a leaf spring 77 which as best seen in FIG. 9 has one end hooked over the web 66 and the opposite end hooked over the outer end of the transverse wall 67. There is a V-shaped bent section 78 in the middle of the leaf spring 77 positioned to engage in a registering one of the notches 76.
The functioning of the adjustment mechanism should be clear from the foregoing, and particularly with reference to FIG. 9. The ramp 50a rests upon the eccentric section 73 at a position determined by the angular orientation of the disc part 72, the latter being retained in the selected position by engagement of the bent section 78 of the leaf spring 77 in the corresponding one of the notches 76 as shown. To alter the position of adjustment, all that is necessary is to insert a tool such as a key through the slot 75 to engage the hexagonal section 74, and by means of such tool apply a rotational force that is sufficient to overcome the resistance of the leaf spring and rotate the disc successively past the other limiting positions as determined by the locations of the notches 76 until the desired position of adjustment is reached. It will be clear that adjustment of the eccentric 73 will have the effect of varying the ramp 50a, and thus varying the dynamic characteristics of the drive pulley.
The adjustment system described is very simple to operate and requires no disassembly of the drive pulley. If desired the disc 72 can bear numbers or other indicia adjacent the notches 76 to give a visual indication as to the position of adjustment of the associated eccentric part 73, since it is most desirable that adjustment of the two ramps 50a should be identical.
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A variable ratio drive pulley designed for use in a belt drive transmission of a snowmobile includes fixed and movable flanges, the movable flange being controlled by centrifugally responsive thrust means employing pivoted weighted levers cooperating with shaped cam surfaces. The dynamic response of the pulley can be adjusted in a simple manner by abutment means supporting the ramps on which the cam surfaces are provided, these abutment means being accessible for adjustment from the exterior of the pulley.
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BACKGROUND OF THE INVENTION
The Ras gene is found activated in many human cancers, including colorectal carcinoma, exocrine pancreatic carcinoma, and myeloid leukemias. Biological and biochemical studies of Ras action indicate that Ras functions like a G-regulatory protein, since Ras must be localized in the plasma membrane and must bind with GTP in order to transform cells (Gibbs, J. et al., Microbial. Rev. 53:171-286(1989). Forms of Ras in cancer cells have mutations that distinguish the protein from Ras in normal cells.
At least 3 post-translational modifications are involved with Ras membrane localization, and all 3 modifications occur at the C-terminus of Ras. The Ras C-terminus contains a sequence motif termed a "CAAX" or "Cys-Aaa 1 -Aaa 2 -Xaa" box (Aaa is an aliphatic amino acid, the Xaa is any amino acid) (Willumsen et al., Nature 310:583-586 (1984)). Other proteins having this motif include the Ras-related GTP-binding proteins such as Rho, fungal mating factors, the nuclear lamins, and the gamma subunit of transducin.
Farnesylation of Ras by the isoprenoid farnesyl pyrophosphate (FPP) occurs in vivo on Cys to form a thioether linkage (Hancock et al., Cell 57:1167 (1989); Casey et al, Proc. Natl Acad. Sci. USA 86:8323 (1989)). In addition, Ha-Ras and N-Ras are palmitoylated via formation of a thioester on a Cys residue near a C-terminal Cys farnesyl acceptor (Gutierrez et al., EMBO J 8:1093-1098 (1989); Hancock et al., Cell 57:1167-1177 (1989); Ki-Ras lacks the palmitate acceptor Cys. The last 3 amino acids at the Ras C-terminal end are removed proteolytically, and methyl esterification occurs at the new C-terminus (Hancock et al, ibid). Fungal mating factor and mammalian nuclear lamins undergo identical modification steps (Anderegg et al, J. Bid. Chem. 263:18236 (1988); Farnsworth et al., J. Biol, Chem. 264:20422 (1989)).
Inhibition of Ras farnesylation in vivo has been demonstrated with lovastatin (Merck & Co., Rahway, N.J.) and compactin (Hancock et al., ibid; Casey et al., ibid; Schafer et al., Science 245:379 (1989)). These drugs inhibit HMG-CoA reductase, the rate limiting enzyme for the production of polyisoprenoids and the farnesyl pyrophosphate precursor. It has been shown that a farnesyl-protein transferase using farnesyl pyrophosphate as a precursor is responsible for Ras farnesylation. (Reiss al., Cell, 62:81-88 (1990); Schaber et al., J. Biol Chem., 265:14701-14704 (1990); Schafer et al., Science, 249:1133-1139 (190); Manne et al., Proc Natl. Acad. Sci USA, 87: 7541-7545 (1990)).
Inhibition of farnesyl-protein transferase and, thereby, of farnesylation of the Ras protein, blocks the ability of Ras to transform normal cells to cancer cells. The compounds of the invention inhibit Ras farnesylation and, thereby, generate soluble Ras which, as indicated infra, can act as a dominant negative inhibitor of Ras function. While soluble Ras in cancer cells can become a dominant negative inhibitor, soluble Ras in normal cells would not be an inhibitor.
A cytosol-localized (no Cys-Aaa 1 -Aaa 2 -Xaa box farnesylation signal domain present) and activated (impaired GTPase activity, staying bound to GTP) form of Ras acts as a dominant negative Ras inhibitor of membrane-bound Ras function (Gibbs et al., Proc. Natl. Acad. Sci. USA 86:6630-6634(1980)). Cytosol-localized forms of Ras with normal GTPase activity do not act as inhibitors. Gibbs et al., ibid, showed this effect in Xenopus oocytes and in mammalian cells.
Administration of compounds of the invention to block Ras farnesylation not only decreases the amount of Ras in the membrane but also generates a cytosolic pool of Ras. In rumor cells having activated Ras, the cytosolic pool acts as another antagonist of membrane-bound Ras function. In normal cells having normal Ras, the cytosolic pool of Ras does not act as an antagonist. In the absence of complete inhibition of farnesylation, other farnesylated proteins are able to continue with their functions.
Farnesyl-protein transferase activity may be reduced or completely inhibited by adjusting the compound dose. Partial reduction of farnesyl-protein transferase enzyme activity by adjusting the compound dose would be useful for avoiding possible undesirable side effects resulting from interference with other metabolic processes which utilize the enzyme.
These compounds and their analogs are inhibitors of farnesyl-protein transferase. Farnesyl-protein transferase utilizes farnesyl pyrophosphate to covalently modify the Cys thiol group of the Ras Cys-Aaa 1 -Aaa 2 -Xaa (CAAX) box with a farnesyl group. While inhibition of farnesyl pyrophosphate biosynthesis by inhibiting HMG-CoA reductase blocks Ras membrane localization in vivo inhibits Ras function, inhibition of farnesyl-protein transferase is more specific and is attended by fewer side effects than is the case for a general inhibitor of isoprene biosynthesis.
Previously, it has been demonstrated that tetrapeptides containing cysteine as an amino terminal residue in a CAAX sequence inhibit Ras farnesylation (Schaber et al., ibid; Reiss et. al., ibid; Reiss et. al., PNAS, 88:732-736 (1991)). Such inhibitors may inhibit while serving as alternate substrates for the Ras farnesyl-transferase enzyme, or may be purely competitive inhibitors (U.S. Pat. No. 5,141,851, University of Texas).
Inhibitors of Ras farnesyl-protein transferase (FPTase) have been described in two general classes. The first are analogs of farnesyl diphosphate (FPP), while the second class of inhibitors is related to the protein substrate for the enzyme, Ras. Almost all of the peptide derived inhibitors that have been described are cysteine containing molecules that are related to the CAAX motif that is the signal for protein prenylation. The exception to this generalization is a class of natural products known as the pepticinnamins (Omura, et al., J. Antibiotics 46:222 (1993). In general, deletion of the thiol from a CAAX derivative dramatically reduces the inhibitory potency of these compounds. However, the thiol group potentially places limitations on the therapeutic application of FPTase inhibitors with respect to pharmacokinetics, pharmacodynamics and toxicity. Therefore, a functional replacement for the thiol is desirable. With the exception of the pepticinnamins, non-thiol FPTase inhibitors that are competitive with the Ras substrate have not been described and are the subject of this invention.
It is, therefore, an object of this invention to develop tetrapeptide-based compounds which do not have a thiol moiety, and which will inhibit farnesyl transferase and the post-translational functionalization of the oncogene Ras protein. It is a further object of this invention to develop chemotherapeutic compositions containing the compounds of this invention and methods for producing the compounds of this invention.
SUMMARY OF THE INVENTION
The present invention comprises analogs of the CAAX motif of the protein Ras that is modified by farnesylation in vivo. These CAAX analogs inhibit the farnesylation of Ras. Furthermore, these CAAX analogues differ from those previously described as inhibitors of Ras farnesyl transferase in that they do not have a thiol moiety. The lack of the thiol offers unique advantages in terms of improved pharmacokinetic behavior in animals, prevention of thiol-dependent chemical reactions, such as rapid autoxidation and disulfide formation with endogenous thiols, and reduced systemic toxicity. Further contained in this invention are chemotherapeutic compositions containing these farnesyl transferase inhibitors and methods for their production.
The compounds of this invention are illustrated by the formulae: ##STR1##
DETAILED DESCRIPTION OF THE INVENTION
The compounds of this invention inhibit the farnesylation of Ras. In a first embodiment of this invention, the Ras farnesyl transferase inhibitors are illustrated by the formula I: ##STR2## wherein: V is CH 2 , O, S, HN, or R 7 N;
R 2 , R 3 , R 4 and R 5 are independently the side chains of naturally occurring amino acids, including their oxidized forms which may be methionine sulfoxide or methionine sulfone, or in the alternative may be substituted or unsubstituted aliphatic, aromatic or heteroaromatic groups, such as allyl, cyclohexyl, phenyl, pyridyl, imidazolyl or saturated chains of 2 to 8 carbon atoms which may be branched or unbranched, wherein the aliphatic substituents may be substituted with an aromatic or heteroaromatic ring;
X-Y is ##STR3## R 7 is an alkyl group, wherein the alkyl group comprises straight chain or branched chain hydrocarbons of 1 to 6 carbon atoms, which may be substituted with an aromatic or heteroaromatic group;
Z is H 2 or O;
m is 0, 1 or 2; and
o is 0, 1, 2 or 3;
or the pharmaceutically acceptable salts thereof.
In a second embodiment of this invention the prodrugs of compounds of formula I are illustrated by the formula II: ##STR4## wherein CH 2 , O, S, HN, or R 7 N;
R 2 , R 3 , R 4 and R 5 are independently the side chains of naturally occurring amino acids, including their oxidized forms which may be methionine sulfoxide or methionine sulfone, or in the alternative may be substituted or unsubstituted aliphatic, aromatic or heteroaromatic groups, such as allyl, cyclohexyl, phenyl, pyridyl, imidazolyl or saturated chains of 2 to 8 carbon atoms which may be branched or unbranched, wherein the aliphatic substituents may be substituted with an aromatic or heteroaromatic ring;
X-Y is ##STR5## R 6 is a substituted or unsubstituted aliphatic, aromatic or heteroaromatic group such as saturated chains of 1 to 8 carbon atoms, which may be branched or unbranched, wherein the aliphatic substituent may be substituted with an aromatic or heteroaromatic ring;
R 7 is an alkyl group, wherein the alkyl group comprises straight chain or branched chain hydrocarbons of 1 to 6 carbon atoms, which may be substituted with an aromatic or heteroaromatic group;
Z is H 2 or O; and
m is 0, 1 or 2;
o is 0, 1, 2 or 3;
or the pharmaceutically acceptable salts.
In a third embodiment of this invention, the inhibitors of farnesyl transferase are illustrated by the formula III: ##STR6## wherein: V is CH 2 , O, S, HN, or R 7 N;
R 2 , R 3 and R 4 are independently the side chains of naturally occurring amino acids, including their oxidized forms which may be methionine sulfoxide or methionine sulfone, or in the alternative may be substituted or unsubstituted aliphatic, aromatic or heteroaromatic groups, such as allyl, cyclohexyl, phenyl, pyridyl, imidazolyl or saturated chains of 2 to 8 carbon atoms which may be branched or unbranched, wherein the aliphatic substituents may be substituted with an aromatic or heteroaromatic ring;
X-Y is ##STR7## R 7 is an alkyl group, wherein the alkyl group comprises straight chain or branched chain hydrocarbons of 1 to 6 carbon atoms, which may be substituted with an aromatic or heteroaromatic group;
Z is H 2 or O;
n is 0, 1 or 2;
m is 0, 1 or 2; and
o is 0, 1, 2 or 3;
or the pharmaceutically acceptable salts thereof.
In a fourth embodiment of this invention the prodrugs of compounds of formula III are illustrated by the formula IV: ##STR8## wherein: V is CH 2 , O, S, HN, or R 7 N;
R 2 , R 3 and R 4 are independently the side chains of naturally occurring amino acids, including their oxidized forms which may be methionine sulfoxide or methionine sulfone, or in the alternative may be substituted or unsubstituted aliphatic, aromatic or heteroaromatic groups, such as allyl, cyclohexyl, phenyl, pyridyl, imidazolyl or saturated chains of 2 to 8 carbon atoms which may be branched or unbranched, wherein the aliphatic substituents may be substituted with an aromatic or heteroaromatic ring;
X-Y is ##STR9## R 7 is an alkyl group, wherein the alkyl group comprises straight chain or branched chain hydrocarbons of 1 to 6 carbon atoms, which may be substituted with an aromatic or heteroaromatic group;
Z is H 2 or O;
n is 0, 1 or 2;
m is 0, 1 or 2; and
o is 0, 1, 2 or 3;
or the pharmaceutically acceptable salts thereof.
The preferred compounds of this invention are as follows:
N-[2(S)-(pyrrolidin-2-on-1-yl)-3-methylbutanoyl]-isoleucyl-methionine;
or
N-[2(S)-(piperidin-2-on-1-yl)-3-methylbutanoyl]-isoleucy-methionine; or the pharmaceutically acceptable salts thereof.
In the present invention, the amino acids which are disclosed are identified both by conventional 3 letter and single letter abbreviations as indicated below:
______________________________________Alanine Ala AArginine Arg RAsparagine Asn NAspartic acid Asp DAsparagine or Asx BAspartic acidCysteine Cys CGlutamine Gln QGlutamic acid Glu EGlutamine or Glx ZGlutamic acidGlycine Gly GHistidine His HIsoleucine Ile ILeucine Leu LLysine Lys KMethionine Met MPhenylalanine Phe FProline Pro PSerine Ser SThreoniune Thr TTryptophan Trp WTyrosine Tyr YValine Val V______________________________________
The compounds of the present invention may have asymmetric centers and occur as racemates, racemic mixtures, and as individual diastereomers, with all possible isomers, including optical isomers, being included in the present invention.
As used herein, "alkyl" is intended to include both branched and straight-chain saturated aliphatic hydrocarbon groups having the specified number of carbon atoms.
The term heterocycle or heterocyclic, as used herein, represents a stable 5- to 7-membered monocyclic or stable 8- to 11-membered bicyclic or stable 11-15 membered tricyclic heterocyclic ring which is either saturated or unsaturated, and which consists of carbon atoms and from one to four heteroatoms selected from the group consisting of N, O, and S, and including any bicyclic group in which any of the above-defined heterocyclic rings is fused to a benzene ring. The heterocyclic ring may be attached at any heteroatom or carbon atom which results in the creation of a stable structure. Examples of such heterocyclic elements include, but are not limited to, azepinyl, benzimidazolyl, benzisoxazolyl, benzofurazanyl, benzopyranyl, benzothiopyranyl, benzofuryl, benzothiazolyl, benzothienyl, benzoxazolyl, chromanyl, cinnolinyl, dihydrobenzofuryl, dihydrobenzothienyl, dihydrobenzothiopyranyl, dihydrobenzothiopyranyl sulfone, furyl, imidazolidinyl, imidazolinyl, imidazolyl, indolinyl, indolyl, isochromanyl, isoindolinyl, isoquinolinyl, isothiazolidinyl, isothiazolyl, isothiazolidinyl, morpholinyl, naphthyridinyl, oxadiazolyl, 2-oxoazepinyl, 2-oxopiperazinyl, 2-oxopiperdinyl, 2-oxopyrrolidinyl, piperidyl, piperazinyl, pyridyl, pyrazinyl, pyrazolidinyl, pyrazolyl, pyrimidinyl, pyrrolidinyl, pyrrolyl, quinazolinyl, quinolinyl, quinoxalinyl, tetrahydrofuryl, tetrahydroisoquinolinyl, tetrahydroquinolinyl, thiamorpholinyl, thiamorpholinyl sulfoxide, thiazolyl, thiazolinyl, thienofuryl, thienothienyl, and thienyl.
The pharmaceutically acceptable salts of the compounds of this invention include the conventional non-toxic salts of the compounds of this invention as formed, e.g., from non-toxic inorganic or organic acids. For example, such conventional non-toxic salts include those derived from inorganic acids such as hydrochloric, hydrobromic, sulfuric, sulfamic, phosphoric, nitric and the like: and the salts prepared from organic acids such as acetic, propionic, succinic, glycolic, stearic, lactic, malic, tartaric, citric, ascorbic, pamoic, maleic, hydroxymaleic, phenylacetic, glutamic, benzoic, salicylic, sulfanilic, 2-acetoxy-benzoic, fumaric, toluenesulfonic, methanesulfonic, ethane disulfonic, oxalic, isethionic, trifluoroacetic and the like.
The pharmaceutically acceptable salts of the compounds of this invention can be synthesized from the compounds of this invention which contain a basic moiety by conventional chemical methods. Generally, the salts are prepared by reacting the free base with stoichiometric amounts or with an excess of the desired salt-forming inorganic or organic acid in a suitable solvent or various combinations of solvents.
The compounds of the invention can be synthesized from their constituent amino acids by conventional peptide synthesis techniques, and the additional methods described below. Standard methods of peptide synthesis are disclosed, for example, in the following works: Schroeder et al., "The Peptides", Vol. I, Academic Press 1965, or Bodanszky et al., "Peptide Synthesis", Interscience Publishers, 1966, or McOmie (ed.) "Protective Groups in Organic Chemistry", Plenum Press, 1973, or Barany et al., "The Peptides: Analysis, Synthesis, Biology" 2, Chapter 1, Academic Press, 1980, or Stewart et al., "Solid Phase Peptide Synthesis", Second Edition, Pierce Chemical Company, 1984. The teachings of these works are hereby incorporated by reference.
Abbreviations used in the description of the chemistry and in the examples that follow are:
______________________________________Ac.sub.2 O Acetic anhydride;Boc t-Butoxycarbonyl;DBU 1,8-diazabicyclo[5.4.0]undec-7-ene;DMAP 4-Dimethylaminopyridine;DME 1,2-Dimethoxyethane;DMF Dimethylformamide;EDC 1-(3-dimethylaminopropyl)-3-ethyl- carbodiimide hydrochloride;HOBT 1-Hydroxybenzotriazole hydrate;Et.sub.3 N Triethylamine;EtOAc Ethyl acetate.FAB Fast atom bombardment;HOOBT 3-Hydroxy-1,2,2-benzotriazin- 4(3H)-one;HPLC High-performance liquid chromatography;MCPBA m-Chloroperoxybenzoic acid;MsCl Methanesulfonyl chloride;NaHMDS Sodium bis(trimethylsilyl)amidePy Pyridine;TFA Trifluoroacetic acid;THF Tetrahydrofuran;______________________________________
Compounds of this invention are prepared by employing the reactions shown in the following Reaction Schemes A-J, in addition to other standard manipulations such as ester hydrolysis, cleavage of protecting groups, etc., as may be known in the literature or exemplified in the experimental procedures. Some key bond-forming and peptide modifying reactions are:
Reaction A. Amide bond formation and protecting group cleavage using standard solution or solid phase methodologies.
Reaction B. Preparation of a reduced peptide subunit by reductive alkylation of an amine by an aldehyde using sodium cyanoborohydride or other reducing agents.
Reaction C. Alkylation of a reduced peptide subunit with an alkyl or aralkyl halide or, alternatively, reductive alkylation of a reduced peptide subunit with an aldehyde using sodium cyanoborohydride or other reducing agents.
Reaction D. Peptide bond formation and protecting group cleavage using standard solution or solid phase methodologies.
Reaction E. Preparation of a reduced subunit by borane reduction of the amide moiety.
These reactions may be employed in a linear sequence to provide the compounds of the invention or they may be used to synthesize fragments which are subsequently joined by the alkylation reactions described in the Reaction Schemes. ##STR10## where R A and R B are R 2 , R 3 or R 4 as previously defined; X L is a leaving group, e.g., Br - , I - or MsO - ; and R 8 is defined such that R 7 is generated by the reductive alkylation process.
Certain compounds of this invention wherein X-Y is an ethenylene or ethylene unit are prepared by employing the reaction sequences shown in Reaction Schemes F and G. Reaction Scheme F outlines the preparation of the alkene isosteres utilizing standard manipulations such as Weinreb amide formation, Grignard reaction, acetylation, ozonolysis, Wittig reaction, ester hydrolysis, peptide coupling reaction, mesylation, cleavage of peptide protecting groups, reductive alkylation, etc., as may be known in the literature or exemplified in the Experimental Procedure. The key reactions are: stereoselective reduction of the Boc-amino-enone to the corresponding syn amino-alcohol (Scheme F, Step B, Part 1), and stereospecific boron triflouride or zinc chloride activated organo-magnesio, organo-lithio, or organo-zinc copper(1) cyanide S N 2' displacement reaction (Scheme F, Step G). Through the use of optically pure N-Boc amino acids as starting material and these two key reactions, the stereochemistry of the final products is well defined. In Step H of Scheme F, the lactam ring is incorporated by acylation of the primary amino group with 4-chlorobutyryl chloride and base-catalyzed cyclization.
The alkane analogs are prepared in a similar manner by including an additional catalytic hydrogenation step as outlined in Reaction Scheme G. ##STR11##
The oxa isostere compounds of this invention are prepared according to the route outlined in Scheme H. An aminoalcohol 1 is acylated with alpha-chloroacetyl chloride in the presence of trialkylamines to yield amide 2. Subsequent reaction of 2 with a deprotonation reagent (e.g., sodium hydride or potassium t-butoxide) in an ethereal solvent such as THF provides morpholinone 3. The N-Boc derivative 4 is then obtained by the treatment of 3 with BOC anhydride and DMAP (4-dimethylaminopyridine) in methylene chloride. Alkylation of 4with R 3 X L , where X L is a leaving group such as Br-, I- or Cl- in THF/DME (1,2-dimethoxyethane) in the presence of a suitable base, preferably NaHMDS [sodium bis(trimethylsilyl)amide], affords 5, which is retreated with NaHMDS followed by either protonation or the addition of an alkyl halide R 4 X to give 6a or 6b, respectively. Alternatively, 6a can be prepared from 4 via an aldol condensation approach. Namely, deprotonation of 4 with NaHMDS followed by the addition of a carbonyl compound R 7 R 8 CO gives the adduct 7. Dehydration of 7 can be effected by mesylation and subsequent elimination catalyzed by DBU (1,8-diazabicyclo[5.4.0]undec-7-ene) or the direct treatment of 7 with phosphorus oxychloride in pyridine to give olefin 8. Then, catalytic hydrogenation of 8 yields 6a. Direct hydrolysis of 6 with lithium hydrogen peroxide in aqueous THF will produce acid 9b. Sometimes, it is more efficient to carry out this conversion via a 2-step sequence, namely, hydrolysis of 6 in hydrochloric acid to afford 9a, which is then derivatized with BOC-ON or BOC anhydride to give 9b. The peptide coupling of acid 9b with either an alpha-aminolactone (e.g., homoserine lactone, etc.) or the ester of an amino acid is carried out under the conditions exemplified in the previously described references to yield derivative 10. Treatment of 10 with gaseous hydrogen chloride gives 11, which undergoes acylation with 4-chlorobutyryl chloride. Base treatment leads to lactam formation. ##STR12##
The thia, oxothia and dioxothia isostere compounds of this invention are prepared in accordance to the route depicted in Scheme I. Aminoalcohol 1 is derivatized with BOC 2 O to give 15. Mesylation of 15 followed by reaction with methyl a-mercaptoacetate in the presence of cesium carbonate gives sulfide 16. Removal of the BOC group in 16 with TFA followed by neutralization with di-isopropylethylamine leads to lactam 17. N-BOC derivative 18 is obtained via the reaction of 17 with BOC anhydride in THF catalyzed by DMAP. Sequential alkylation of 18 with the alkyl halides R 3 X and R 4 X in THF/DME using NaHDMS as the deprotonation reagent produces 19. Hydrolysis of 19 in hydrochloride to yield 20a, which is derivatized with Boc anhydride to yield 20b. The coupling of 20b with an alpha-aminolactone (e.g., homoserine lactone, etc.) or the ester of an amino acid is carried out under conventional conditions as exemplified in the previously described references to afford 21. Sulfide 21 is readily oxidized to sulfone 22 by the use of MCPBA (m-chloroperoxybenzoic acid). The N-BOC group of either 21 or 22 is readily removed by treatment with gaseous hydrogen chloride. The resultant amine hydrochloride 23 can be converted to the lactam as described above. ##STR13##
The compounds of this invention inhibit Ras farnesyl transferase which catalyzes the first step in the post-translational processing of Ras and the biosynthesis of functional Ras protein. These compounds are useful as pharmaceutical agents for mammals, especially for humans. These compounds may be administered to patients for use in the treatment of cancer. Examples of the type of cancer which may be treated with the compounds of this invention include, but are not limited to, colorectal carcinoma, exocrine pancreatic carcinoma, and myeloid leukemias.
The compounds of this invention may be administered to mammals, preferably humans, either alone or, preferably, in combination with pharmaceutically acceptable carriers or diluents, optionally with known adjuvants, such as alum, in a pharmaceutical composition, according to standard pharmaceutical practice. The compounds can be administered orally or parenterally, including the intravenous, intramuscular, intraperitoneal, subcutaneous, rectal and topical routes of administration.
For oral use of a chemotherapeutic compound according to this invention, the selected compound may be administered, for example, in the form of tablets or capsules, or as an aqueous solution or suspension. In the case of tablets for oral use, carriers which are commonly used include lactose and corn starch, and lubricating agents, such as magnesium stearate, are commonly added. For oral administration in capsule form, useful diluents include lactose and dried corn starch. When aqueous suspensions are required for oral use, the active ingredient is combined with emulsifying and suspending agents. If desired, certain sweetening and/or flavoring agents may be added. For intramuscular, intraperitoneal, subcutaneous and intravenous use, sterile solutions of the active ingredient are usually prepared, and the pH of the solutions should be suitably adjusted and buffered. For intravenous use, the total concentration of solutes should be controlled in order to render the preparation isotonic.
The present invention also encompasses a pharmaceutical composition useful in the treatment of cancer, comprising the administration of a therapeutically effective amount of the compounds of this invention, with or without pharmaceutically acceptable carriers or diluents. Suitable compositions of this invention include aqueous solutions comprising compounds of this invention and pharmacologically acceptable carriers, e.g., saline, at a pH level, e.g., 7.4. The solutions may be introduced into a patient's intramuscular blood-stream by local bolus injection.
When a compound according to this invention is administered into a human subject, the daily dosage will normally be determined by the prescribing physician with the dosage generally varying according to the age, weight, and response of the individual patient, as well as the severity of the patient's symptoms.
In one exemplary application, a suitable amount of compound is administered to a mammal undergoing treatment for cancer. Administration occurs in an amount between about 0.1 mg/kg of body weight to about 20 mg/kg of body weight per day, preferably of between 0.5 mg/kg of body weight to about 10 mg/kg of body weight per day.
EXAMPLES
Examples provided are intended to assist in a further understanding of the invention. Particular materials employed, species and conditions are intended to be further illustrative of the invention and not limitative of the reasonable scope thereof.
The standard workup referred to in the examples refers to solvent extraction and washing the organic solution with 10% citric acid, 10% sodium bicarbonate and brine as appropriate. Solutions were dried over sodium sulfate and evaporated in vacuo on a rotary evaporator.
EXAMPLE 1
Preparation of N-[2(S)-(pyrrolidin-2-on-1-yl)-3-methylbutanoyl]-isoleucyl-methionine
Step A: Preparation of N-4-chlorobutanoylvalyl-isoleucyl-methionine methyl ester
The hydrochloride salt of valyl-isoleucyl-methionine methyl ester was obtained using standard solution phase synthesis methods. To a suspension of this tripeptide (150 mg, 0.38 mmol) in 10 mL methylene chloride at 0° C. was added pyridine (61 mL, 0.75 mmol), 43 mL of 4-chlorobutanoyl chloride (0.38 mmol) and 5 drops of DMF. The mixture was stirred for 15 min. at 0° C. and then at room temperature overnight. The reaction was worked up in the standard manner to afford 130 mg of crude product. This material was further purified by chromatography on silica gel (98:2 methylene chloride:methanol) and trituration with a mixture of ether and methylene chloride. The solid product weighed 70 mg.
Step B: Preparation of N-[2(S)-(pyrrolidin-2-on-1-yl)-3-methylbutanoyl]-isoleucyl-methionine
The product of Step A was suspended in 5 mL of methanol and 0.6 mL of 1N NaOH was added. After 1 h. the methanol was evaporated, the residue was dissolved in water and filtered. The filtrate was acidified and the product was extracted into ethyl acetate. After standard workup, a solid was obtained, which was washed with water and ether. After drying the solid weighed 25 mg. FAB mass spectrum m/z=430 (M+1).
Anal. Calcd for C 20 H 35 N 3 O 5 S.0.2H 2 O: C, 55.46; H, 8.24; N, 9.70. Found: C, 55.45; H, 7.88; N, 9.61.
EXAMPLE 2
Preparation of N-[2(S)-(piperidin-2-on-1-yl)-3-methylbutanoyl]-isoleucyl-methionine
Step A: Preparation of N-(5-chloropentanoyl)valine methyl ester
Using the method of Example 1, Step A, valine methyl ester and 5-chloropentanoyl chloride were coupled to provide N-(5-chloropentanoyl)valine methyl ester.
Step B: Preparation of Methyl 2(S)-(piperidin-2-on-1-yl)-3-methylbutanoate
A solution of 105 mg (0.42 mmol) of the product of Step A in 10 mL of dry THF was treated with 17 mg (0.43 mmol) of 60% NaH in oil dispersion at 0° C. for 1 h. TLC analysis indicated starting material was present and 2 mL of DMF was added. After 1.5 h. at 0° C., the solvent was evaporated and the mixture was worked up in the standard to give 90 mg of product.
Step C: Preparation of 2(S)-(Piperidin-2-on-1-yl)-3-methylbutanoic acid
The product of Step B was dissolved in 4 mL of methanol and 0.85 mL of 1N NaOH was added. The mixture was stirred overnight and the solvent was evaporated. The residue was dissolved in water, filtered and acidified. Ethyl acetate extraction and standard workup gave 30 mg of the title compound.
Step D: Preparation of N-[2(S)-(piperidin-2-on-1-yl)-3-methylbutanoyl]-isoleucyl-methionine
The product of Step C was coupled to the dipeptide isoleucyl-methionine methyl ester using a standard protocol. Following saponification of the methionine ester, the title compound was obtained. 1 H-NMR of this material indicated that it was a 1:1 mixture of diastereomers, due to racemization of the valine residue.
EXAMPLE 3
In Vitro inhibition of Ras farnesyl transferase
Farnesyl-protein transferase (FTase) from bovine brain was chromatographed on DEAE-Sephacel-(Pharmacia, 0-0.8M NaCl gradient elution), N-octyl agarose (Sigma, 0-0.6M NaCl gradient elution), and a mono Q HPLC column (Pharmacia, 0-0.3M NaCl gradient). Ras-CVLS at 3.5 mM, 0.25 mM [ 3 H]FPP, and the indicated compounds were incubated with either a partially purified bovine enzyme preparation or a recombinant human enzyme preparation. The FTase data presented below in Table 1 reflects the ability of the test compound to inhibit RAS farnesylation in vitro, as described in Pompliano, et al., Biochemistry 31, 3800 (1992).
TABLE 1______________________________________Inhibition of RAS farnesylation by compounds of thisinvention* IC.sub.50______________________________________N-[2(S)-(pyrrolidin-2-on-1-yl)-3-methylbutanoyl]- 2000isoleucyl-methionineN-[2(S)-(piperidin-2-on-1-yl)-3-methylbutanoyl]- 6200isoleucyl-methionine______________________________________ *(IC.sub.50 is the concentration of the test compound which gives 50% inhibition of FTase under the described assay conditions).
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The present invention comprises analogs of the CAAX motif of the protein Ras that is modified by farnesylation in vivo. These CAAX analogs inhibit the farnesylation of Ras. Furthermore, these CAAX analogues differ from those previously described as inhibitors of Ras farnesyl transferase in that they do not have a thiol moiety. The lack of the thiol offers unique advantages in terms of improved pharmacokinetic behavior in animals, prevention of thiol-dependent chemical reactions, such as rapid autoxidation and disulfide formation with endogenous thiols, and reduced systemic toxicity. Further contained in this invention are chemotherapeutic compositions containing these farnesyl transferase inhibitors and methods for their production.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a dry-type analytical element suitable for measuring the enzyme activity of a liquid sample, particularly a biological body fluid.
2. Description of the Prior Art
A known dry-type analytical element for measuring lactate dehydrogenase (LDH) contains lactic acid or its salt and nicotinamide adenine dinucleotide coenzyme (NAD + ) of the oxidized form in its water-permeable layer and nicotinamide adenine dinucleotide coenzyme of reduced form (NADH) is detected by a coloring reagent or the like. Such an analytical element for LDH activity assey is disclosed in Japanese patent KOKAI 59-88097, etc., and it is suitable for measuring the LDH activity of a liquid sample. In such analytical elements, the density of the background sometimes increases during the handling required for measurement, and as a result, the calibration curve previously prepared cannot be utilized. This phenomenon was remarkable, when polyvinylpyrrolidone known as the stabiliser and NAD + (Japanese Patent KOKOKU 49-27717) was added to the water-permeable layer containing NAD + as the binder.
SUMMARY OF THE INVENTION
The present inventors have investigated this problem, and have found that when the LDH activity analytical element containing NAD + in a water-permeable layer is left for a long time under a light, particularly a fluorescent light the background density increases.
An object of the invention is to provide an analytical element suitable for measuring the LDH activity of a liquid sample having one or more water-permeable layers, at least one of the water-permeable layers being a porous spreading layer and at least one of the water-permeable layers containing lactic acid or its salt and NAD + , wherein increase of the background during handling is minimized, and thereby, an accurate measured value can easily be obtained.
Another object of the invention is to provide an analytical element suitable for measuring the enzyme activity of a liquid sample, which measurement is not limited to LDH activity of a liquid sample. The element has one or more water-permeable layers, with at least one of the water-permeable layers containing a substrate of the enzyme and NAD + . The element exhibits minimal increase of the background during handling, allowing an accurate measured value to be easily obtained.
Such objects have been achieved by incorporating a polymer and acrylamide, methacrylamide or their derivatives into a water-permeable layer of the analytical element.
Thus, the present invention provides a dry-type analytical element suitable for measuring the enzyme activity of a liquid sample. The element has one or more water-permeable layers wherein, at least one of the water-permeable layers is a porous spreading layer, and at least one of the water-permeable layers contains NAD + . In such an analytical element, the analytical element of the invention is characterized by that at least one of the water-permeable layers contains a hydrophilic polymer of acrylamide, methacrylamide or their derivatives.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The hydrophilic polymer usable in the analytical element of the invention is a polymer of the monomer component shown in the general formula [I] or a copolymer of this monomer component and other monomer component(s). ##STR1##
In the formula, R 1 represents a hydrogen atom or a lower alkyl group, and R 2 and R 3 represent a hydrogen atom, an aliphatic hydrocarbon group or an aromatic hydrocarbon group. R 2 may be identical with or different from R 3 . R 2 may be joined to R 3 to form a ring, such as, piperidine or morpholine ring.
The lower alkyl group of R 1 includes the methyl group. Examples of R 2 and R 3 other than hydrogen atom include the methyl group, ethyl group, benzyl group, hydroxyethyl group, cyclohexyl group, phenyl group, piperidino group and morpholino group.
Examples of the monomer shown in the general formula [I] are acrylamide, N-methylacrylamide, N-ethylacrylamide, N-isopropylacrylamide, N,N-dimethylacrylamide, N-acryloylpiperidine, methacrylamide, N-methylmethacrylamide, N-ethylmethacrylamide, N-isopropylmethacrylamide and N,N-dimethylmethacrylamide.
The other monomer component in the case of the copolymer includes acrylic acid, methacrylic acid, maleic acid, methylacrylate, ethylmethacrylate, styrene and ethylene. In addition, the monomers and copolymerized components described in the specification of Japanese Patent Application No. 61-143754 are also usable. The copolymer may be composed of two or more kinds of the monomer component shown in the general formula [I]. The copolymer may be composed of more than two kinds of monomers.
The hydrophilic polymer employed in the invention is water-soluble, and its molecular weight is about 5,000 to 2,000,000, preferably 20,000 to 500,000.
The hydrophilic polymer is incorporated into a water-permeable layer of the analytical element, preferably the water-permeable layer containing NAD + . The hydrophilic polymer may be incorporated into the two or more water-permeable layers. The porous spreading layer is the most preferable layer to incorporate the hydrophilic polymer. The suitable content of the hydrophilic polymer is about 0.2 to 10 mg/m 2 , preferably 0.5 to 5 mg/m 2 .
The analytical element of the invention is suitable for measuring enzyme activity, and it comprises NAD + . Such an analytical element usually contains a substrate and reagents capable of reacting with NADH to generate a detectable change such as coloration, discoloration or emission of fluorescence. As such reagents, a combination of an electron carrier and a formazan dye precursor is preferable. The electron carrier may be selected from diaphorase, N-methylphenazonium methosulfate and the like. The most preferable formazan dye precursor is Nitrotetrazolium Blue (NTB or NBT, 3,3'-(3,3'-dimethoxy-4,4'-biphenylene)-bis [2-(p-nitrophenyl)-5-phenyltetrazolium chloride]). However, other formazan dye precursors such as INT (2-(p-iodophenyl)-3-(p-nitrophenyl)-5-phenltetrazolium chloride), BT (3,3'-(3,3'-dimethoxy-4,4'-biphenylene)-bis[2,5-diphenyltetrazolium chloride]), 3,3'-(4,4'-biphenylene)-bis [2,5-diphenyltetrazolium chloride] and the like are also usable. The substrate is selected according to the kind of the enzyme to be measured, and in the case of LDH, lactic acid or its salt is employed. Examples of other enzymes than LDH are aldehyde reductase, glycerol dehydrogenase, malate dehydrogenase and the like.
NAD + and the substrate are incorporated into reagent layer, spreading layer or other water-permeable layer(s). They may be incorporated into the same layer, or they may separately be incorporated into different layers. Moreover, either of them may be incorporated into two or more layers, such as, the spreading layer and reagent layer, light-blocking layer and reagent layer, first reagent layer and second reagent layer, or spreading layer and first reagent layer. In such cases, the contents in the two or more layers may be different from each other. The porous spreading layer is the most preferable layer to incorporate NAD + and the substrate. In any event, the substrate is also preferably incorporated into the layer containing the hydrophilic polymer. The contents of NAD + and the substrate may be identical with a conventional analytical element. The reagents capable of reacting with NADH are also incorporated into the reagent layer, spreading layer or other water-permeable layer(s). They may be incorporated into the same layer or different layers, and either of them may be incorporated into one layer or two or more layers.
The present invention can be applied to various known dry-type analytical elements. The analytical element may be a multilayer element containing a support and water-permeable layer(s), such as, a registration layer, a light-blocking layer, a reagent layer, a porous spreading layer (hereinafter shortly referred to as spreading layer), an adhesive layer, a filtering layer, a water-absorption layer, an undercoating layer and other known layers. Some embodiments are disclosed in U.S. Pat. No. 3,992,158, U.S. Pat. No. 4,042,335 and Japanese Patent KOKAI 55-164356.
The following embodiments may be used in practice for the analytical elements of the invention containing a support.
(1) A spreading layer also utilized as a reagent layer superposed on the support. A water-absorption layer may be incorporated between the spreading layer and the support.
(2) A spreading layer, a reagent layer and the support superposed in this order. A water-absorption layer may be incorporated between the reagent layer and the support. The hydrophilic polymer is incorporated in either or both of the spreading layer and the reagent layer.
(3) A spreading layer, a reagent layer, a registration layer and the support superposed in this order. The hydrophilic polymer dye is incorporated in either or both of the spreading layer and the reagent layer.
(4) A spreading layer, a light-reflecting layer, a reagent layer and the support superposed in this order. One or more of the spreading layer, the light-reflecting layer and the reagent layer contain the hydrophilic polymer.
(5) A spreading layer also utilized as a reagent layer, a light-reflecting layer, a registration layer and the support superposed in this order. The spreading layer contains the hydrophilic polymer.
(6) A spreading layer, a light-reflecting layer, a reagent layer, a registration layer and the support superposed in this order. Either or both of the spreading layer and the reagent layer contains the hydrophilic polymer.
(7) A spreading layer, a reagent layer, a light-reflecting layer, a registration layer and the support superposed in this order. At least, the spreading layer or the reagent layer contains the hydrophilic polymer.
(8) A spreading layer, a first reagent layer, a light-reflecting layer, a second reagent layer, a registration layer and the support superposed in this order. At least, the second reagent layer or one of the layers located on the side contrary to the support therefrom contains the hydrophilic polymer.
Preferable embodiments for the present invention are (2) and (4). In any embodiment of (2) to (8), a water-absorption layer may be incorporated between the reagent layer or the registration layer and the support. In the embodiment of (2) or (3), a filtering layer may be incorporated between the reagent layer and the registration layer or the spreading layer or between plural reagent layers. In any embodiment of (4) to (8), a filtering layer may be incorporated between the light-reflecting layer and the spreading layer, the reagent layer or the registration layer, between the reagent layer and the registration layer, between the spreading layer and the reagent layer, or between the first reagent layer and the second reagent layer.
The water-impermeable light-transmissive support includes a transparent film or sheet made of polyethylene terephthalate, polycarbonate, polystyrene, cellulose ester such as cellulose triacetate and cellulose acetate propionate, or the like. The thickness of the support is usually in the range of about 50 μm to about 1 mm, preferably from about 80 μm to about 300 μm. The support may be provided with an undercoating layer on its surface in order to strengthen the adhesion of the layer laminated on it, such as, a registration layer. Instead of the undercoating layer, the surface of the support may be treated by a physical activation, such as, glow discharge or corona discharge or by a chemical activation.
The registration layer or the water-absorption layer provided on the support is preferably composed of a hydrophilic binder, that is, a hydrophilic polymer which absorbs water to swell. The registration layer is the layer where a color material produced from the indicator diffuses, and the water-absorption layer is the layer where the color material cannot substantially diffuse. The hydrophilic polymer is generally a natural or synthetic hydrophilic polymer having a swelling ratio in the range of about 1.5 to about 20 preferably from about 2.5 to about 15 at a water absorption at 30° C. Examples of the hydrophilic polymer are gelatins, such as, alkali-treated gelatin, acid-treated gelatin and deionized gelatin, gelatin derivatives, such as, phthalated gelatin, agarose and polyacrylamide. The thicknesses of the registration layer and water-absorption layer are usually in the range of about 1 μm to about 50 μm, preferably about 3 μm to 30 μm in the dry state. These layers may contain a surfactant, such as, a cationic surfactant, an anionic surfactant, an ampholytic surfactant or a nonionic surfactant and a pH buffer.
An adhesive layer may be provided for laminating a spreading layer on a water-absorption layer, registration layer, light-reflecting layer, filtering layer, reagent layer or the like. The adhesive layer is preferably composed of a hydrophilic polymer capable of adhering to the spreading layer when the adhesive layer is dampened or absorbs water to swell. Such a hydrophilic polymer may be selected from the hydrophilic polymers usable for the registration layer described above. Preferably hydrophilic polymers are gelatins, gelatin derivatives, polyacrylamide and the like. The thickness of the adhesive layer is usually in the range of about 0.5 μm to about 20 μm, preferably about 1 μm to about 10 μm in dry state. The adhesive layer may be provided for the adhesion of other layer. The adhesive layer is formed by applying an aqueous solution of a hydrophilic polymer and other compound added, if necessary.
The reagent layer of the analytical element of the invention may contain a hydrophilic polymer and a pH buffer, if necessary. Examples of the hydrophilic polymer include starch, cellulose, agarose, gelatin and their derivatives such as phthalated gelatin, polyacrylamide, copolymers of acrylamide and various vinyl monomer, polymethacrylamide and copolymers of methacrylamide and various vinyl monomers. The pH buffers suitable for the reagent layer include carbonate buffers, borate buffers, phosphate buffers and Good's buffers. Examples of these buffers are described in "Tanpakushitsu.Koso no Kiso-Jikken Ho (Fundamental Experimental Method of Proteins, Enzymes)" (Horio et al., Nankodo, Japan, 1981).
The light-reflecting layer blocks the color of the sample spotted on the spreading layer. In the case of a whole blood sample, this is due to hemoglobin. The light blocking effect takes place at the time of measuring the optically detectable change, such as, the color change or coloration occurring in the registration layer, reagent layer or other layer(s), from the side of the light-transmissive support by reflection photometry. This layer functions either as a light-blocking layer or a background layer. The light-reflecting layer is preferably a water-permeable layer composed of a hydrophilic polymer as binder wherein light-reflecting particles, such as, titanium dioxide or barium sulfate are dispersed. Examples of the hydrophilic polymer include the foregoing hydrophilic polymers usable for the registration layer, weakly hydrophilic regenerated cellulose and cellulose acetate. Preferable hydrophilic polymers are gelatins, gelatin derivatives and polyacrylamide. A known hardening agent may be added to the gelatin or a gelatin derivative. The light-reflecting layer may be formed by applying an aqueous solution of a hydrophilic polymer wherein titanium dioxide particles or the like are suspended followed by drying. In the analytical element of the invention, titanium dioxide particles or the like may be incorporated in spreading layer, reagent layer, registration layer or the like.
The spreading layer preferably has a metering action. The metering action is such that a sample spotted on the spreading layer spreads at a fixed amount per unit area without uneven distribution of any component in the sample in horizontal directions. The material constituting the matrix of the spreading layer may be filter paper, nonwoven fabric, woven fabrics, such as, plain weaves, knitted fabrics, such as, tricot fabric, glass fiber filter paper, membrane filter formed of blushed polymer, and three-dimensional lattice structure material composed of polymer particulates, etc. Preferable materials for the spreading layer are fibrous materials, such as, woven fabrics and knitted fabrics. These are explained in detail in U.S. Pat. No. 4,292,272, GB No. 2,087,074A and EP No. 0,162,302A. These woven fabrics and knitted fabrics are preferably degreased, such as, by washing.
The dry-type analytical element of the invention is preferably cut into square or circular pieces having a side or diameter of about 15 mm to about 30 mm, and put in a slide frame disclosed in Japanese Patent KOKAI 57-63452, U.S. Pat. No. 4,169,751, U.S. Pat. No. 4,387,990, PCT application WO No. 83/00391, etc. to use.
The measurement is carried out, for example, according to the manner disclosed in the specifications of the foregoing patents. An aqueous sample of about 5 μl to about 30 μl, preferably about 8 μl to about 15 μl is spotted on the spreading layer, and incubated at a definite temperature in the range of about 20° C. to about 45° C. for a prescribed time, if necessary. Thereafter, a color change or coloring in the analytical element is measured from the side of the support by reflection photometry, and the subject component in the sample is determined by the principle of colorimetry.
EXAMPLES
EXAMPLE 1
The support employed was a colorless transparent polyethylene terephthalate (PET) film having a thickness of 180 μm on which a gelatin undercoating was provided. The following aqueous solution was applied on the support at the rate of 133 cc/m 2 and then dried to form a dye-forming layer having a dry thickness of 10 μm.
______________________________________Gelatin 190 gOctylphenoxypolyethoxyethanol 30 gNitrotetrazolium Blue* 9.5 gWater 1,350 gAdjusted to pH 6.5 by dil. NaOH solution.______________________________________ *3,3(3,3dimethoxy 4,4biphenylene)-bis[2 (pnitrophenyl)-5-phenyltetrazolium chloride
The above dye-forming layer was moistened with 30 g/m 2 of water. A PET tricot fabric cloth knitted from 50 deniers PET spun yarn by 36 gauges was lightly pressed on it to laminate it as the spreading layer, followed by drying.
Subsequently, the following aqueous solution was uniformly applied on the spreading layer at the rate of 120 cc/m 2 , and dried to obtain an integral multilayer analytical element for measuring LDH activity.
______________________________________Nonylphenoxypolyethoxyethanol (n = 40) 1 gOctylphenoxypolyethoxyethanol (n = 10) 1 gTris(hydroxymethyl)aminomethane 6 gLithium lactate 3 gPolyacrylamide 25 g(Molecular Weight; about 200,000)β-NAD.sup.+ 0.6 gDiaphorase 150,000 UWater 100 gAdjusted to pH 8.5 by dil. HCl solution.______________________________________
A comparative analytical element 1 was prepared in the same manner as the above example except that 25 g of polyvinylpyrrolidone was added instead of 25 g of polyacrylamide.
These analytical elements were irradiated at 25° C. by a white fluorescent light ("NATIONAL FLUORESCENT LIGHT FLR/40S-W/M-X") at an illuminance of 1,000 luxes for the times described in Table 1. After the irradiation, reflection optical density of each element was measured at 540 nm from the side of the support. The results are tabulated in Table 1.
TABLE 1______________________________________Irradiation Reflection Optical DensityTime (min.) Invention Comparative______________________________________ 0 0.426 0.442 5 0.431 0.45210 0.437 0.46115 0.442 0.47230 0.455 0.494Difference 0.029 0.052between30 min. and 0 min.______________________________________
As shown in Table 1, the analytical element of the invention exhibits much less influence by a fluorescent light as compared to the comparative analytical element 1.
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A dry-type analytical element suitable for measuring enzyme activity of in a liquid sample, characterized by incorporating a polyacrylamide, polymethacrylamide or their derivatives into at least one water-permeable layer. The background concentration of the dry-type analytical element exhibits minimal increase even under a fluorescent light, and allows an accurate measured value to be easily obtained.
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APPLICATION DATA
This application claims benefit to German application DE 10 2004 034 623.2 filed Jul. 16, 2004.
The present invention relates to new 6-formyl-tetrahydropteridines of general formula (I)
wherein the groups R 1 to R 6 have the meanings given in the claims and specification, the isomers thereof, processes for preparing these 6-formyl-tetrahydropteridines and their use as medicaments.
BACKGROUND TO THE INVENTION
Pteridinone derivatives are known from the prior art as active substances with an antiproliferative activity. WO 01/019825 and WO 03/020722 describe the use of pteridinone derivatives for the treatment of tumoral diseases.
Tumour cells wholly or partly elude regulation and control by the body and are characterised by uncontrolled growth. This is based on the one hand on the loss of control proteins, such as e.g. Rb, p16, p21 and p53 and also on the activation of so-called accelerators of the cell cycle, the cyclin-dependent kinases (CDK's).
In addition, the protein kinase Aurora B has been described as having an essential function during entry into mitosis. Aurora B phosphorylates histone H3 at Ser10 and thus initiates chromosome condensation (Hsu et al. 2000, Cell 102:279-91). A specific cell cycle arrest in the G2/M phase may however also be triggered e.g. by the inhibition of specific phosphatases such as e.g. Cdc25C (Russell and Nurse 1986, Cell 45:145-53). Yeasts with a defective Cdc25 gene arrest in the G2 phase, while overexpression of Cdc25 leads to premature entry into the mitosis phase (Russell and Nurse 1987, Cell 49:559-67). Moreover, an arrest in the G2/M phase may also be triggered by the inhibition of certain motor proteins, the so-called kinesins such as e.g. Eg5 (Mayer et al. 1999, Science 286:971-4), or by agents which stabilise or destabilise microtubules (e.g. colchicin, taxol, etoposide, vinblastin, vincristine) (Schiff and Horwitz 1980, Proc Natl Acad Sci USA 77:1561-5).
In addition to the cyclin-dependent and Aurora kinases the so-called polo-like kinases, a small family of serine/threonine kinases, play an important part in the regulation of the eukaryotic cell cycle. Hitherto, the polo-like kinases PLK-1, PLK-2, PLK-3 and PLK-4 have been described in the literature. PLK-1 in particular has been shown to play a central part in the regulation of the mitosis phase. PLK-1 is responsible for the maturation of the centrosomes, for the activation of phosphatase Cdc25C, and for the activation of the Anaphase Promoting Complex (Glover et al. 1998, Genes Dev. 12:3777-87; Qian et al. 2001, Mol Biol Cell. 12:1791-9). The injection of PLK-1 antibodies leads to a G2 arrest in untransformed cells, whereas tumour cells arrest in the mitosis phase (Lane and Nigg 1996, J. Cell Biol. 135:1701-13). Overexpression of PLK-1 has been demonstrated for various types of tumour, such as non-small-cell lung cancer, plate epithelial carcinoma, breast and colorectal carcinoma (Wolf et al. 1997, Oncogene 14 :543-549; Knecht et al. 1999, Cancer Res. 59:2794-2797; Wolf et al. 2000, Pathol. Res. Pract. 196:753-759; Takahashi et al. 2003, Cancer Sci. 94:148-52). Therefore, this category of proteins also constitutes an interesting approach to therapeutic intervention in proliferative diseases (Liu and Erikson 2003, Proc Natl Acad Sci USA 100:5789-5794).
The resistance of many types of tumours calls for the development of new pharmaceutical compositions for combating tumours.
The aim of the present invention is to provide new compounds having an antiproliferative activity.
DETAILED DESCRIPTION OF THE INVENTION
Surprisingly it has been found that compounds of general formula (I) wherein the groups R 1 to R 6 have the meanings given hereinafter act as inhibitors of specific cell cycle kinases particularly the polo-like kinases. The compounds named have an antiproliferative activity, in that they arrest cells in the mitosis phase of the cell cycle before programmed cell death is initiated in the arrested cells. Thus, the compounds according to the invention may be used for example to treat diseases connected with the activity of specific cell cycle kinases and characterised by excessive or abnormal cell proliferation.
The present invention therefore relates to compounds of general formula (I)
wherein
R 1 , R 2 which may be identical or different denote a group selected from among optionally substituted C 1 -C 10 -alkyl, C 2 -C 10 -alkenyl, C 2 -C 10 -alkynyl, aryl, heteroaryl, C 3 -C 8 -cycloalkyl, C 3 -C 8 -heterocycloalkyl, —X-aryl, —X-heteroaryl, —X-cycloalkyl, —X-heterocycloalkyl, —NR 7 -aryl, —NR 7 -heteroaryl, —NR 7 -cycloalkyl and —NR 7 -heterocycloalkyl,
or
a group selected from among hydrogen, halogen, COXR 7 , CON(R 7 ) 2 , COR 7 and XR 7 ,
or
R 1 and R 2 together denote a 2- to 5-membered alkyl bridge which may contain 1 to 2 heteroatoms, R 3 denotes hydrogen or a group selected from among optionally substituted C 1 -C 12 -alkyl, C 2 -C 12 -alkenyl, C 2 -C 12 -alkynyl, aryl, heteroaryl, —C 3 -C 12 -cycloalkyl, C 3 -C 12 -cycloalkenyl, C 7 -C 12 -polycycloalkyl, C 7 -C 12 -polycycloalkenyl and C 5 -C 12 -spirocycloalkyl or R 1 and R 3 or R 2 and R 3 together denote a saturated or unsaturated C 3 -C 4 -alkyl bridge which may contain 1 to 2 heteroatoms, R 4 denotes optionally substituted aryl, benzyl or heteroaryl, R 5 denotes hydrogen, —CO—NH—C 1 -C 4 -alkyl, —CO—C 1 -C 4 -alkyl or —CO—X—C 1 -C 4 -alkyl, R 6 denotes a group selected from among hydrogen, NH 2 , XH, halogen and einer optionally by one or more halogen atoms substituted C 1 -C 3 -alkyl group, R 7 each independently of one another denote hydrogen or a group selected from among optionally substituted C 1 -C 4 -alkyl, C 2 -C 4 -alkenyl, C 2 -C 4 -alkynyl, benzyl and phenyl,
and
X denotes O or S,
optionally in the form of the tautomers, racemates, enantiomers, diastereomers and mixtures thereof, and optionally the pharmacologically acceptable acid addition salts, solvates or hydrates thereof.
Preferred are compounds of formula (I), wherein
R 1 to R 4 and R 7 are as hereinbefore defined and R 5 and R 6 denote hydrogen.
Also preferred are compounds of formula (I), wherein
R 3 to R 7 are as hereinbefore defined and R 1 , R 2 which may be identical or different denote hydrogen or a group selected from among optionally substituted C 1 -C 6 -alkyl, C 2 -C 6 -alkenyl, and C 2 -C 6 -alkynyl,
or
R 1 and R 2 together denote a 2- to 5-membered alkyl bridge.
Also preferred are compounds of formula (I), wherein
R 1 , R 2 and R 4 to R 7 are as hereinbefore defined,
and
R 3 is hydrogen or a group selected from among optionally substituted C 1 -C 12 -alkyl, C 2 -C 12 -alkenyl, C 2 -C 12 -alkynyl and C 6 -C 14 -aryl, or a group selected from among optionally substituted C 3 -C 12 -cycloalkyl, C 3 -C 12 -cycloalkenyl, C 7 -C 12 -polycycloalkyl, C 7 -C 12 -polycycloalkenyl and C 5 -C 12 -spirocycloalkyl.
Particularly preferred are compounds of formula (I), wherein
R 1 to R 3 and R 5 to R 7 are as hereinbefore defined,
and
R 4 denotes a group of general formula
R 8 which may be identical or different denote hydrogen or a group selected from among optionally substituted C 1 -C 6 -alkyl, C 2 -C 6 -alkenyl, C 2 -C 6 -alkynyl, —O—C 1 -C 6 -alkyl, —O—C 2 -C 6 -alkenyl, —O—C 2 -C 6 -alkynyl, heterocycloalkyl, C 3 -C 6 -cycloalkyl, aryl, heteroaryl, —O-aryl, —O-heteroaryl, —O-cycloalkyl, and —O-heterocycloalkyl or
a group selected from among hydrogen, —CONH 2 , —COOR 7 , —OCON(R 7 ) 2 , —N(R 7 ) 2 , —NHCOR 7 , —NHCON(R 7 ) 2 , —NO 2 , CF 3 , halogen, —O—C 1 -C 6 -alkyl-Q 1 , —CONR 7 —C 1 -C 10 -alkyl-Q 1 , —CONR 7 —C 1 -C 10 -alkenyl-Q 1 , —CONR 7 —Q 2 , halogen, OH, —SO 2 R 7 , —SO 2 N(R 7 ) 2 , —COR 7 , —COOR 7 , —N(R 7 ) 2 , —NHCOR 7 , —CONR 7 OC 1 -C 10 -alkyl-Q 1 and CONR 7 O—Q 2 ,
or
adjacent R 8 groups together denote a bridge of general formula a), b), c) or d),
Y denotes O, S or NR 11 ,
m denotes 0, 1 or 2
R 9 denotes C 1 -C 6 -alkyl
R 10 denotes hydrogen or a group selected from among optionally substituted phenyl, pyridyl, pyrazinyl, pyrimidinyl, pyridazinyl, —C 1 -C 3 -alkyl-phenyl, —C 1 -C 3 -alkyl-pyridyl, —C 1 -C 3 -alkyl-pyrazinyl, —C 1 -C 3 -alkyl-pyrimidinyl and —C 1 -C 3 -alkyl-pyridazinyl, piperidinyl, piperazinyl,
R 11 denotes hydrogen or C 1 -C 4 -alkyl
Q 1 denotes hydrogen, —NHCOR 7 , or a group selected from among an optionally substituted —NH-aryl, —NH-heteroaryl, aryl, heteroaryl, C 3 -C 8 -cycloalkyl and heterocycloalkyl group,
Q 2 denotes hydrogen or a group selected from among an optionally substituted aryl, heteroaryl, C 3 -C 8 -heterocycloalkyl-, C 3 -C 8 -cycloalkyl- and C 1 -C 4 -alkyl-C 3 -C 8 -cycloalkyl group,
and
n denotes 0, 1, 2, 3, 4 or 5.
Particularly preferred are compounds of formula (I), wherein
Q 1 , Q 2 , n, R 4 to R 8 are as hereinbefore defined, R 1 , R 2 which may be identical or different denote hydrogen or a group selected from among methyl, ethyl, propyl, allyl and propargyl
or
R 1 and R 2 together denote cyclopropyl, R 3 is hydrogen, or denotes optionally substituted C 1 -C 6 -alkyl or optionally substituted C 3 -C 12 -cycloalkyl.
Most preferred are compounds of formula (I), wherein
Q 1 , Q 2 , n, R 1 to R 4 , R 6 to R 7 have the meanings specified,
and
R 8 which may be identical or different denote hydrogen or a group selected from among halogen, (C 1 -C 2 -alkyl) 2 N, CF 3 , NH 2 SO 2 , —CONH—C 6 -C 14 -aryl, —CONH—C 1 -C 4 -alkyl-C 6 -C 14 -aryl and —O—C 1 -C 4 -alkyl, CONH—C 3 -C 8 -cycloalkyl-heterocycloalkyl.
The invention further relates to compounds of formula (I) for use as pharmaceutical compositions.
Of particular importance according to the invention are compounds of formula (I) for use as pharmaceutical compositions with an antiproliferative activity.
The invention also relates to the use of a compound of formula (I) for preparing a pharmaceutical composition for the treatment and/or prevention of diseases selected from among cancer, bacterial and viral infections, inflammatory and autoimmune diseases, chemotherapy-induced alopecia and mucositis, cardiovascular diseases, nephrological diseases, as well as chronic and acute neurodegenerative diseases, preferably for the treatment of cancer, inflammatory and autoimmune diseases, particularly preferably for the treatment of cancer and inflammatory diseases.
The invention further relates to the use of a compound of formula (I) for preparing a pharmaceutical composition for inhibiting the polo-like kinases, particularly the polo-like kinase PLK-1.
The invention further relates to the use of a compound of formula (I) for preparing a pharmaceutical composition for the treatment and/or prevention of tumour diseases based on the overexpression of the polo-like kinases, particularly the PLK-1 kinases.
The invention further relates to a method for the treatment and/or prevention of diseases selected from among cancer, bacterial and viral infections, inflammatory and autoimmune diseases, chemotherapy-induced alopecia and mucositis, cardiovascular diseases, nephrological diseases, as well as chronic and acute neurodegenerative diseases, preferably for the treatment of cancer, inflammatory and autoimmune diseases, particularly preferably for the treatment of cancer and inflammatory diseases, in which an effective amount of a compound of formula (I) is administered to a patient.
The invention also relates to pharmaceutical preparations, containing as active substance one or more compounds of general formula (I) optionally combined with conventional excipients and/or carriers.
The term alkyl groups, including alkyl groups which are a part of other groups, denotes branched and unbranched alkyl groups with 1 to 12 carbon atoms, preferably 1-6, most preferably 1-4 carbon atoms, such as, for example: methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl and decyl. Unless otherwise stated, the abovementioned terms propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl and decyl include all the possible isomeric forms. For example, the term propyl includes the two isomeric groups n-propyl and iso-propyl, the term butyl includes n-butyl, iso-butyl, sec. butyl and tert.-butyl, the term pentyl includes iso-pentyl, neopentyl, etc.
In the abovementioned alkyl groups one or more hydrogen atoms may optionally be replaced by other groups. For example these alkyl groups may be substituted by methyl, chlorine or fluorine, preferably fluorine. All the hydrogen atoms of the alkyl group may optionally also be replaced.
The term alkyl bridge, unless otherwise stated, denotes branched and unbranched alkyl groups with 2 to 5 carbon atoms, for example ethylene, propylene, isopropylene, n-butylene, iso-butyl, sec. butyl and tert.-butyl etc. bridges. Ethylene, propylene and butylene bridges are particularly preferred. In the alkyl bridges mentioned 1 to 2 C-atoms may optionally be replaced by one or more heteroatoms selected from among oxygen, nitrogen or sulphur.
The term alkenyl groups (including those which are a part of other groups) denotes branched and unbranched alkylene groups with 2 to 10 carbon atoms, preferably 2 to 6 carbon atoms, most preferably 2-3 carbon atoms, provided that they have at least one double bond. Examples include: ethenyl, propenyl, butenyl, pentenyl etc. Unless otherwise stated, the abovementioned terms propenyl, butenyl, etc also include all the possible isomeric forms. For example, the term butenyl includes 1-butenyl, 2-butenyl, 1-methyl-1-propenyl, 1-methyl-2-propenyl, 2-methyl-1-propenyl, 2-methyl-2-propenyl and 1-ethyl-1-ethenyl.
In the abovementioned alkenyl groups, unless otherwise stated, one or more hydrogen atoms may optionally be replaced by other groups. For example, these alkenyl groups may be substituted by methyl, chlorine or fluorine, preferably fluorine. All the hydrogen atoms of the alkenyl group may optionally also be replaced.
The term alkynyl groups (including those which are a part of other groups) denotes branched and unbranched alkynyl groups with 2 to 10 carbon atoms, provided that they have at least one triple bond, for example ethynyl, propargyl, butynyl, pentynyl, hexynyl etc., preferably ethynyl or propynyl.
In the abovementioned alkynyl groups, unless otherwise stated, one or more hydrogen atoms may optionally be replaced by other groups. For example, these alkynyl groups may be substituted by methyl, chlorine or fluorine, preferably fluorine. All the hydrogen atoms of the alkynyl group may optionally also be replaced.
The term aryl denotes an aromatic ring system with 6 to 14 carbon atoms, preferably 6 or 10 carbon atoms, preferably phenyl, which, unless otherwise stated, may carry one or more of the following substituents, for example: OH, NO 2 , CN, OMe, —OCHF 2 , —OCF 3 , —NH 2 , halogen, preferably fluorine or chlorine, C 1 -C 10 -alkyl, preferably C 1 -C 5 -alkyl, preferably C 1 -C 3 -alkyl, particularly preferably methyl or ethyl, —O—C 1 -C 3 -alkyl, preferably —O-methyl or —O-ethyl, —COOH, —COO—C 1 -C 4 -alkyl, preferably —O-methyl or —O-ethyl, or —CONH 2 .
As heteroaryl groups wherein up to two C atoms are replaced by one or two nitrogen atoms may be mentioned, for example, pyrrole, pyrazole, imidazole, triazole, pyridine, pyrimidine, while each of the above-mentioned heteroaryl rings may optionally also be anellated to a benzene ring, preferably benzimidazole, and these heterocycles, unless stated to the contrary, may for example carry one or more of the following substituents: F, Cl, Br, OH, OMe, methyl, ethyl, CN, CONH 2 , NH 2 , optionally substituted phenyl, optionally substituted heteroaryl, preferably optionally substituted pyridyl.
Examples of cycloalkyl groups are cycloalkyl groups with 3-12 carbon atoms, preferably 3-8 carbon atoms, for example cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl or cyclooctyl, preferably cyclopropyl, cyclopentyl or cyclohexyl, while each of the above-mentioned cycloalkyl groups may optionally be bridged and/or may also carry one or more substituents, for example: OH, NO 2 , CN, OMe, —OCHF 2 , —OCF 3 , —NH 2 or halogen, preferably fluorine or chlorine, C 1 -C 10 -alkyl, preferably C 1 -C 5 -alkyl, preferably C 1 -C 3 -alkyl, particularly preferably methyl or ethyl, —O—C 1 -C 3 -alkyl, preferably —O-methyl or —O-ethyl, —COOH, —COO—C 1 -C 4 -alkyl, preferably —COO-methyl or —COO-ethyl or —CONH 2 . Particularly preferred substituents of the cycloalkyl groups are ═O, OH, NH 2 , methyl or F.
Examples of cycloalkenyl groups are cycloalkyl groups with 3-12 carbon atoms which have at least one double bond, for example cyclopropenyl, cyclobutenyl, cyclopentenyl, cyclohexenyl or cycloheptenyl, preferably cyclopropenyl, cyclopententyl or cyclohexenyl, while each of the above-mentioned cycloalkenyl groups may optionally be bridged and/or may also carry one or more substituents.
“═O” denotes an oxygen atom linked by a double bond.
Examples of heterocycloalkyl groups, unless otherwise stated in the definitions, are 3 to 12 membered, preferably 5-, 6- or 7-membered, saturated or unsaturated heterocycles, which may contain as heteroatoms nitrogen, oxygen or sulphur, for example tetrahydrofuran, tetrahydrofuranone, γ-butyrolactone, α-pyran, γ-pyran, dioxolane, tetrahydropyran, dioxane, dihydrothiophene, thiolane, dithiolane, pyrroline, pyrrolidine, pyrazoline, pyrazolidine, imidazoline, imidazolidine, tetrazole, piperidine, pyridazine, pyrimidine, pyrazine, piperazine, triazine, tetrazine, morpholine, thiomorpholine, diazepan, oxazine, tetrahydro-oxazinyl, isothiazole, pyrazolidine, preferably morpholine, pyrrolidine, piperidine or piperazine, while the heterocyclic group may optionally be bridged and/or may also carry substituents, for example C 1 -C 4 -alkyl, preferably methyl, ethyl or propyl.
Examples of polycycloalkyl groups are optionally substituted, bi-, tri-, tetra- or pentacyclic cycloalkyl groups, for example pinane, 2.2.2-octane, 2.2.1-heptane or adamantane. Examples of polycycloalkenyl groups are optionally bridged and/or substituted, 8-membered bi-, tri-, tetra- or pentacyclic cycloalkenyl groups, preferably bicycloalkenyl or tricycloalkenyl groups, if they contain at least one double bond, for example norbornene.
Examples of spiroalkyl groups are optionally substituted spirocyclic C 5 -C 12 alkyl groups.
The term halogen generally denotes fluorine, chlorine, bromine or iodine, preferably fluorine, chlorine or bromine, particularly preferably chlorine.
The compounds according to the invention may be present in the form of the individual optical isomers, mixtures of the individual enantiomers, diastereomers or racemates, in the form of the tautomers, in the form of the solvates, preferably in the form of the hydrates thereof and also in the form of the free bases or the corresponding acid addition salts with pharmacologically acceptable acids—such as for example acid addition salts with hydrohalic acids, for example hydrochloric or hydrobromic acid, or organic acids, such as for example oxalic, fumaric, diglycolic or methanesulphonic acid.
The substituent R 1 may represent a group selected from among optionally substituted C 1 -C 10 -alkyl, preferably C 1 -C 4 -alkyl, particularly preferably methyl, ethyl or propyl, C 2 -C 10 -alkenyl, preferably allyl, C 2 -C 10 -alkynyl, preferably propargyl, aryl, preferably phenyl, heteroaryl, C 3 -C 8 -cycloalkyl, C 3 -C 8 -heterocycloalkyl, —X-aryl, —X-heteroaryl, —X-cycloalkyl, —X-heterocycloalkyl, —NR 7 -aryl, —NR 7 -heteroaryl, —NR 7 -cycloalkyl and —NR 7 -heterocycloalkyl,
or
a group selected from among hydrogen, halogen, COXR 7 , CON(R 7 ) 2 , COR 7 and XR 7 .
Preferably the substituent R 1 denotes ethyl or hydrogen, particularly preferably hydrogen.
The substituent R 2 may represent a group selected from among optionally substituted C 1 -C 10 -alkyl, preferably C 1 -C 4 -alkyl, particularly preferably methyl, ethyl or propyl, C 2 -C 10 -alkenyl, preferably allyl, C 2 -C 10 -alkynyl, preferably propargyl, aryl, preferably phenyl, heteroaryl, C 3 -C 8 -cycloalkyl, C 3 -C 8 -heterocycloalkyl, —X-aryl, —X-heteroaryl, —X-cycloalkyl, —X-heterocycloalkyl, —NR 7 -aryl, —NR 7 -heteroaryl, —NR 7 -cycloalkyl and —NR 7 -heterocycloalkyl,
or
a group selected from among hydrogen, halogen, COXR 7 , CON(R 7 ) 2 , COR 7 and XR 7 .
Preferably the substituent R 2 denotes methyl, ethyl, allyl, propargyl or hydrogen, particularly preferably methyl or ethyl.
The substituents R 1 and R 2 may together denote a 2- to 5-membered alkyl bridge, preferably a 2-membered alkyl bridge which may contain 1 to 2 heteroatoms, for example oxygen, sulphur or nitrogen, preferably oxygen or nitrogen.
The substituent R 3 may represent hydrogen or a group selected from among optionally substituted C 1 -C 12 -alkyl, preferably C 2 -C 6 -alkyl, particularly preferably pentyl, C 2 -C 12 -alkenyl, C 2 -C 12 -alkynyl, aryl, heteroaryl, C 3 -C 12 -cycloalkyl, C 3 -C 12 -cycloalkenyl, C 7 -C 12 -polycycloalkyl, C 7 -C 12 -polycycloalkenyl and C 5 -C 12 -spirocycloalkyl or
R 1 and R 3 or R 2 and R 3 together denote a saturated or unsaturated C 3 -C 4 -alkyl bridge which may contain 1 to 2 heteroatoms.
Preferably the substituent R 3 denotes C 1 -C 6 -alkyl or —C 3 -C 12 -cycloalkyl, particularly preferably pentyl or cyclopentyl.
The substituent R 4 may optionally represent substituted aryl, benzyl or heteroaryl, preferably a group of general formula
The index n may represent 0, 1, 2, 3, 4 or 5, preferably 1 or 2, particularly preferably 1.
The substituent R 5 may represent a group selected from among hydrogen, —CO—NH—C 1 -C 4 -alkyl, —CO—C 1 -C 4 -alkyl or —CO—X—C 1 -C 4 -alkyl. Preferably the substituent R 5 denotes hydrogen.
The substituent R 6 may represent a group selected from among hydrogen, NH 2 , XH, halogen and a C 1 -C 3 -alkyl group optionally substituted by one or more halogen atoms.
Preferably the substituent R 6 denotes hydrogen.
The substituent R 7 may each independently of one another denote hydrogen or a group selected from among optionally substituted C 1 -C 4 -alkyl, preferably methyl or ethyl, C 2 -C 4 -alkenyl, C 2 -C 4 -alkynyl, benzyl and phenyl. Preferably the substituent R 7 denotes hydrogen.
X may in each case independently of one another represent oxygen or sulphur, preferably oxygen.
The substituent R 8 which may be identical or different may denote hydrogen or a group selected from among optionally substituted C 1 -C 6 -alkyl, C 2 -C 6 -alkenyl, C 2 -C 6 -alkynyl, —O—C 1 -C 6 -alkyl, —O—C 2 -C 6 -alkenyl, —O—C 2 -C 6 -alkynyl, heterocycloalkyl, C 3 -C 6 -cycloalkyl, aryl, heteroaryl, —O-aryl, —O-heteroaryl, —O-cycloalkyl, and —O-heterocycloalkyl or
a group selected from among hydrogen, —CONH 2 , —COOR 7 , —OCON(R 7 ) 2 , —N(R 7 ) 2 , —NHCOR 7 —NHCON(R 7 ) 2 , —NO 2 , CF 3 , halogen, —O—C 1 -C 6 -alkyl-Q 1 , —CONR 7 -C 1 -C 10 -alkyl-Q 1 , —CONR 7 —C 1 -C 10 -alkenyl-Q 1 , —CONR 7 -Q 2 , halogen, OH, —SO 2 R 7 , —SO 2 N(R 7 ) 2 , —COR 7 , —COOR 7 , —N(R 7 ) 2 , —NHCOR 7 , —CONR 7 OC 1 -C 10 -alkyl-Q 1 and CONR 7 O—Q 2 ,
or
adjacent groups R 8 together denote a bridge of general formula a), b), c) or d),
Preferably the substituent R 8 denotes aryl, preferably phenyl, heteroaryl, particularly preferably pyridyl or pyrimidinyl, or a group selected from among —CONR 7 —Q 2 , preferably —CONH—Q 2 , —CONR 7 —C 1 -C 10 -alkyl-Q 1 , preferably —CONH—C 1-2 —Q, or —CONH—C 2 —Q 1 , CONR 7 —C 3 -C 8 -cycloalkyl-Q 1 , preferably —CONH-cyclohexyl-Q 1 or —CONH-cyclopentyl-Q 1
Y may represent O, S or NR 11 , preferably NR 11 .
m denotes 0, 1 or 2, preferably 1.
The substituent R 9 may represent C 1 -C 6 -alkyl, preferably methyl.
The substituent R 10 may represent hydrogen or a group selected from among optionally substituted phenyl, pyridyl, pyrazinyl, pyrimidinyl, pyridazinyl, piperidinyl, piperazinyl, —C 1 -C 3 -alkyl-phenyl, —C 1 -C 3 -alkyl-pyridyl, —C 1 -C 3 -alkyl-pyrazinyl, —C 1 -C 3 -alkyl-pyrimidinyl and —C 1 -C 3 -alkyl-pyridazinyl.
Particularly preferably R 10 denotes pyridyl, pyrimidinyl, piperidinyl, piperazinyl.
The substituent R 11 may represent hydrogen or C 1 -C 4 -alkyl, preferably hydrogen or methyl.
Q 1 may represent hydrogen, —NHCOR 7 , or a group selected from among an optionally substituted —NH-aryl, —NH-heteroaryl, aryl, preferably phenyl, heteroaryl, C 3 -C 8 -cycloalkyl and heterocycloalkyl group.
Particularly preferably Q 1 denotes heteroaryl or heterocycloalkyl, particularly preferably pyridinyl, pyrimidinyl, morpholinyl, piperazinyl or piperidinyl, Q 2 denotes hydrogen or a group selected from among an optionally substituted aryl, preferably phenyl, heteroaryl, C 3 -C 8 -heterocycloalkyl-, C 3 -C 8 -cycloalkyl and C 1 -C 4 -alkyl-C 3 -C 8 -cycloalkyl group.
m may represent 0, 1, 2, 3, 4 or 5, preferably 1.
The compounds of general formula (I) may be prepared by the following method of synthesis, wherein the substituents of general formulae (A1) to (A4) and (I) have the above-mentioned meanings.
This method is to be understood as illustrating the invention without restricting it to the object thereof.
A compound of formula (A1) is reduced to the compound of formula (A2) which then forms 2-chloro-6-formyl-tetrahydropteridine (A3) with formic acid. Then compounds of general formula (A3) are reacted with a substituted amine to produce general formula (I), which may optionally undergo further transformations. Compounds of formula (A1) may be obtained according to WO 2003020722. 4-amino-N-cyclopropyl benzamide may be prepared for example according to the following literature: B. W. Horrem and T. E. Lynes, J. Med. Chem. 1963, 6, 528-532. trans-4-morpholino-cyclohexylamine 10 was prepared by the following methods:
Dibenzyl-4-morpholino-cyclohexylamine
3.9 g (30 mmol)) 4-dibenzylcyclohexanone were dissolved in 100 mL CH 2 Cl 2 and stirred with 3.9 g (45 mmol) morpholine and 9.5 g (45 mmol) of NaBH(OAc) 3 for 12 hours at 25° C. Then the mixture was combined with water and potassium carbonate, the organic phase was separated off, dried and evaporated down. The residue was purified through a silica gel column (eluant: ethyl acetate 90/methanol 10+1% conc. ammonia). The appropriate fractions were evaporated down in vacuo.
Yield: 6.6 g (60%) cis-isomer and 2 g (18%) trans-isomer.
Alternatively, trans-dibenzyl-4-morpholino-cyclohexylamine may be prepared by the following method:
33 g (112 mmol) 4-dibenzylcyclohexanone were dissolved in 300 mL methanol, combined with 17.4 g (250 mmol) hydroxylamine hydrochloride and stirred for 4 hours at 60° C. The solvent was evaporated down in vacuo, combined with 500 mL water and 50 g potassium carbonate and extracted twice with 300 mL dichloromethane. The organic phases were dried, evaporated down in vacuo, the residue was crystallised from petroleum ether, dissolved in 1.5 L ethanol and heated to 70° C. 166 g of sodium was added batchwise and refluxed until the sodium dissolved. The solvent was removed, the residue was combined with 100 mL water and extracted twice with 400 mL ether. The organic phases were washed with water, dried, evaporated down in vacuo and the trans-isomer was isolated through a column (eluant: ethyl acetate 80/methanol 20+2% conc. ammonia).
Yield: 12.6 g (41%).
6.8 g (23 mmol) trans-1-amino-4-dibenzylaminocyclohexane was dissolved in 90 mL DMF and stirred with 5 mL (42 mmol) 2,2′-dichloroethylether and 5 g potassium carbonate for 8 hours at 100° C. After cooling, 30 mL water was added, the precipitated crystals were suction filtered and purified through a short column (eluant: ethyl acetate). The residue was crystallised from methanol and conc. hydrochloric acid as the dihydrochloride.
Yield: 7.3 g (72%).
General Procedures:
Step 1
In Step 1, 1 equivalent of compound (A1) and 1 to 5 equivalents, preferably 3-4 equivalents of sodium borohydride were stirred with boron trifluoride etherate in a diluent such as tetrahydrofuran, diethyl ether or dioxane, preferably tetrahydrofuran, for 12-24 h at 15-40° C.
To isolate the product the reaction mixture is then combined with water and hydrochloric acid and the organic solvent is eliminated in vacuo. The aqueous phase is then made basic with a base such as ammonia or sodium carbonate and extracted two to three times with an organic solvent such as, for example, diethyl ether or ethyl acetate, preferably ethyl acetate. The combined organic extracts are dried and the solvent is distilled off. The residue (compound A2) may be used in Step 2 without prior purification.
Step 2
The compound (A2) obtained in Step 1 is dissolved in formic acid and refluxed for 5 min to 1 h, preferably 15 minutes, to form the compound (A3). Then the formic acid is removed by distillation and the residue is recrystallised by the addition of one or more organic solvents, for example ethyl acetate, diethyl ether, dichloromethane, acetone, petroleum ether.
Step 3
a) In Step 3, 1 equivalent of the 2-chloro-6-formyl-tetrahydropteridine (A3) is mixed with 1-3 equivalents of an amine and heated for 30 minutes to 4 h at 120° to 180° C., preferably 160° C. (see Diagram 2). After cooling the mixture is taken up in a suitable solvent and the product is crystallised or subjected to chromatographic purification.
b) Alternatively, in Step 3, 1 equivalent of 2-chloro-6-formyl-tetrahydropteridine (A3) may also be stirred with 1-3 equivalents of an amine in an organic solvent such as dioxane or tetrahydrofuran, with 1 equivalent of an acid, for example p-toluenesulphonic acid, for 8 h to 48 h at reflux temperature. After cooling the mixture is taken up in a suitable solvent and the product is crystallised or subjected to chromatographic purification.
SYNTHESIS OF EXAMPLES 1 AND 5
In order to synthesise Examples 1 and 5 first of all an intermediate compound 2
is prepared as described hereinafter.
Synthesis of Intermediate Compound 2:
2 g of compound 1 are dissolved in 50 mL tetrahydrofuran and stirred with 1 g sodium borohydride and 3 mL boron trifluoride etherate at 25° C. for 18 h. Then 2 mL water and 20 mL 2N hydrochloric acid were added dropwise and the mixture was refluxed for 10 minutes. Then the tetrahydrofuran was separated off by distillation, the residue was combined with ammonia solution and the aqueous phase was extracted 2× with 50 mL ethyl acetate. The organic phase was washed with water, dried and evaporated down in vacuo. Any crystals precipitated were filtered off and washed with ether. 1.5 g of a compound 3 were obtained which was used for the next reaction without any further purification.
1.4 g of compound 3 were dissolved in 10 mL formic acid and refluxed for 15 minutes. Then the solution was evaporated down in vacuo and the residue was combined with ether, the precipitate was filtered off and washed with ether. This yielded 1.2 g of a product 4 which was used in the next step without any further purification.
1.2 g of compound 4 was stirred with 2.78 g ethyl 4-aminobenzoate without solvent for 2 h at 150° C. After cooling the reaction mixture was combined with 50 mL ethyl acetate, the precipitate formed was filtered off and washed with ether. This yielded 1.1 g of a product 5 which was used in the next step without any further purification.
1.1 g of compound 5 was dissolved in 10 mL methanol and 1 mL water and combined with 0.4 g sodium hydroxide, then the mixture was stirred for 24 h at 30° C. It was then evaporated down in vacuo, combined with 20 mL water and 0.8 mL acetic acid and extracted 2× with 50 mL methylene chloride. The organic phase was dried, evaporated down in vacuo and crystallised from acetone. 0.7 g of a solid 2 were obtained which was used for subsequent reactions.
EXAMPLE 1
0.1 g of 2 was stirred together with 0.5 g cyclopropylamine, 0.1 g of o-benzotriazolyl,N,N,N′, N′-tetramethyluronium tetrafluoroborate (TBTU), 0.5 mL N-ethyldiisopropylamine in 2 mL dimethylformamide for 30 minutes. Then 50 mL water and 1 g potassium carbonate was added and the mixture was extracted 2× with 50 mL dichloromethane. The organic phase was dried and evaporated down in vacuo. Then the mixture was fractionated by chromatography on silica gel, and the crude product thus obtained was dissolved in acetone, the solution was combined with ethereal HCl, evaporated down and crystallised from ether. 25 mg of a yellow powder were obtained.
EXAMPLE 5
0.1 g of 2 was stirred with 0.15 g of 3-aminopyridine, 0.1 g TBTU, 0.5 g N-ethyldiisopropylamine in 2 mL dimethylformamide for 2 h at 120° C. Then it was combined with 50 mL water and 1 g potassium carbonate and extracted twice with 50 mL methylene chloride. The organic phase was dried, the mixture was fractionated by chromatography on silica gel, the appropriate fractions were evaporated down in vacuo and the residue was crystallised from acetone. 10 mg of a yellow solid were obtained.
SYNTHESIS OF EXAMPLES 6 AND 8
In order to synthesise Examples 6 and 8 first of all an intermediate compound 7
is prepared as described below.
Synthesis of the Intermediate Compound 7:
4 g of compound 6 is dissolved in 100 mL tetrahydrofuran and stirred with 2 g sodium borohydride and 6 mL boron trifluoride etherate at 25° C. for 18 h. Then first 4 mL water then 40 mL 2N hydrochloric acid were slowly added dropwise to the suspension and the mixture was refluxed for 10 minutes. Then the tetrahydrofuran was separated off by distillation, the residue was combined with ammonia solution and the aqueous phase was extracted 2× with in each case 100 mL ethyl acetate. The organic phase was washed with water, dried and evaporated down in vacuo. Precipitated crystals were filtered off and washed with ether. 3 g of a compound 8 were obtained which was used for the next reaction without further purification.
0.6 g of compound 8 were dissolved in 5 mL formic acid and refluxed for 15 minutes. Then the solution was evaporated down in vacuo and the residue was combined with ethyl acetate and petroleum ether, the precipitate was filtered off and the mother liquor was evaporated down. This yielded 0.58 g of a yellow oily product 7 which was used for the subsequent reactions without further purification.
EXAMPLE 6
0.1 g of 7 was heated to 160° C. with 0.14 g 4-amino-N-cyclopropylbenzamide without solvent for 45 minutes. After cooling the reaction mixture was dissolved in dichloromethane and methanol and fractionated on silica gel. Suitable fractions were combined and evaporated down in vacuo. The residue was dissolved in ethyl acetate, combined with oxalate solution from isopropanol, diethyl ether and petroleum ether and the precipitate formed was filtered off and dried. 30 mg of a white solid were obtained.
EXAMPLE 8
0.46 g of 7 was stirred with 0.32 g 4-amino-3-methoxybenzoic acid and 0.32 g p-toluenesulphonic acid in 10 mL dioxane at reflux temperature for 48 h. The reaction mixture was evaporated down and fractionated on silica gel. Suitable fractions were combined and evaporated down in vacuo. The residue was combined with a little ethyl acetate and petroleum ether, the resulting precipitate was filtered off and dried. 0.3 g of the acid 9 were obtained as a beige solid which was used for subsequent reactions without any additional purification.
0.065 g of 9 together with 0.047 g TBTU, 0.2 mL ethyldiisopropylamine in 2 mL dichloromethane was combined with trans-4-morpholino-cyclohexylamine 10 and stirred for 14 hours at 25° C. Then the mixture was diluted with more dichloromethane and the organic phase was extracted with water and potassium carbonate solution. Then the organic phase was evaporated down and the residue was fractionated by chromatography on silica gel. Suitable fractions were evaporated down and the residue was crystallised by the addition of ethyl acetate and petroleum ether. 50 mg of a white solid were obtained.
The compounds of general formula (I) listed in Table 1, inter alia, are obtained analogously to the procedures described above.
TABLE 1
Ex-
Config.
ample
R1/R2
R 1
R 2
R 3
R 4
molecular weight
ESI, [M + H]
melting point
1
R
H
422.53
423
2
R
H
473.58
474
3
R
H
382.47
383
4
R
H
473.58
474
5
R
H
459.55
460
6
R
H
434.54
435
7
R
H
521.66
522
8
R
H
591.75
592
154° C.
9
R
H
612.78
613
118° C.
10
R
H
598.75
599
173° C.
*binding site
As has been found, the compounds of general formula (I) are characterised by their wide range of applications in the therapeutic field. Particular mention should be made of those applications in which the inhibition of specific cell cycle kinases, particularly the inhibiting effect on the proliferation of cultivated human tumour cells but also the proliferation of other cells, such as endothelial cells, for example, plays a part.
As could be demonstrated by DNA staining followed by FACS analysis, the inhibition of proliferation brought about by the compounds according to the invention is mediated by the arrest of the cells, particularly at the G2/M phase of the cell cycle. The cells arrest, depending on the cells used, for a specific length of time in this phase of the cell cycle before programmed cell death is initiated. An arrest in the G2/M phase of the cell cycle is triggered, for example, by the inhibition of specific cell cycle kinases. In view of their biological properties the compounds of general formula I according to the invention, their isomers and their physiologically acceptable salts are suitable for the treatment of diseases characterised by excessive or abnormal cell proliferation.
Such diseases include, for example: viral infections (e.g. HIV and Kaposi's sarcoma); inflammatory and autoimmune diseases (e.g. colitis, arthritis, Alzheimer's disease, glomerulonephritis and wound healing); bacterial, fungal and/or parasitic infections; leukaemias, lymphoma and solid tumours; skin diseases (e.g. psoriasis); bone diseases; cardiovascular diseases (e.g. restenosis and hypertrophy). They are also suitable for protecting proliferating cells (e.g. hair, intestinal, blood and progenitor cells) from damage to their DNA caused by radiation, UV treatment and/or cytostatic treatment (Davis et al., 2001).
The new compounds may be used for the prevention, short-term or long-term treatment of the abovementioned diseases, also in combination with other active substances used for the same indications, e.g. cytostatics, hormones or antibodies.
The activity of the compounds according to the invention was determined in the PLK1 inhibition assay, in the cytotoxicity test on cultivated human tumour cells and/or in a FACS analysis, for example on HeLaS3 cells. In both test methods, the compounds exhibited a good to very good activity, i.e. for example an EC 50 value in the HeLaS3 cytotoxicity test of less than 5 μmol/L, generally less than 1 μmol/L and an IC 50 value in the PLK1 inhibition assay of less than 1 μmol/L.
PLK1 Kinase Assay
Preparation of Enzyme:
Recombinant human PLK1 enzyme attached to GST at its N-terminal end is isolated from Baculovirus-infected insect cells (Sf21). Purification is carried out by affinity chromatography on glutathione sepharose columns.
4×10 7 Sf21 cells ( Spodoptera frugiperda ) in 200 ml of Sf-900 II Serum free insect cell medium (Life Technologies) are seeded in a spinner flask. After 72 hours' incubation at 27° C. and 70 rpm, 1×10 8 Sf21 cells are seeded in a total of 180 ml medium in a new spinner flask. After another 24 hours, 20 ml of recombinant Baculovirus stock suspension are added and the cells are cultivated for 72 hours at 27° C. at 70 rpm. 3 hours before harvesting, okadaic acid is added (Calbiochem, final concentration 0.1 μM) and the suspension is incubated further. The cell number is determined, the cells are removed by centrifuging (5 minutes, 4° C., 800 rpm) and washed 1× with PBS (8 g NaCl/I, 0.2 g KCl/I, 1.44 g Na 2 HPO 4 /I, 0.24 g KH 2 PO 4 /I). After centrifuging again the pellet is flash-frozen in liquid nitrogen. Then the pellet is quickly thawed and resuspended in ice-cold lysing buffer (50 mM HEPES pH 7.5, 10 mM MgCl 2 , 1 mM DTT, 5 μg/ml leupeptin, 5 μg/ml aprotinin, 100 μM NaF, 100 μM PMSF, 10 mM β-glycerolphosphate, 0.1 mM Na 3 VO 4 , 30 mM 4-nitrophenylphosphate) to give 1×10 8 cells/17.5 ml. The cells are lysed for 30 minutes on ice. After removal of the cell debris by centrifugation (4000 rpm, 5 minutes) the clear supernatant is combined with glutathione sepharose beads (1 ml resuspended and washed beads per 50 ml of supernatant) and the mixture is incubated for 30 minutes at 4° C. on a rotating board. Then the beads are washed with lysing buffer and the recombinant protein is eluted from the beads with 1 ml eluting buffer/ml resuspended beads (eluting buffer: 100 mM Tris/HCl pH=8.0, 120 mM NaCl, 20 mM reduced glutathione (Sigma G-4251), 10 mM MgCl 2 , 1 mM DTT). The protein concentration is determined by Bradford Assay.
Assay
The following components are combined in a well of a 96-well round-bottomed dish (Greiner bio-one, PS Microtitre plate No. 650101):
10 μl of the compound to be tested in variable concentrations (e.g. beginning at 300 μM, and dilution to 1:3) in 6% DMSO, 0.5 mg/ml casein (Sigma C-5890), 60 mM β-glycerophosphate, 25 mM MOPS pH=7.0, 5 mM EGTA, 15 mM MgCl 2 , 1 mM DTT 20 μl substrate solution (25 mM MOPS pH=7.0, 15 mM MgCl 2 , 1 mM DTT, 2.5 mM EGTA, 30 mM β-glycerophosphate, 0.25 mg/ml casein) 20 μl enzyme dilution (1:100 dilution of the enzyme stock in 25 mM MOPS pH=7.0, 15 mM MgCl 2 , 1 mM DTT) 10 μl ATP solution (45 μM ATP with 1.11×10 6 Bq/ml gamma-P33-ATP).
The reaction is started by adding the ATP solution and continued for 45 minutes at 30° C. with gentle shaking (650 rpm on an IKA Schüttler MTS2). The reaction is stopped by the addition of 125 μl of ice-cold 5% TCA per well and incubated on ice for at least 30 minutes. The precipitate is transferred by harvesting onto filter plates (96-well microtitre filter plate: UniFilter-96, GF/B; Packard; No. 6005177), then washed four times with 1% TCA and dried at 60° C. After the addition of 35 μl scintillation solution (Ready-Safe; Beckmann) per well the plate is sealed shut with sealing tape and the amount of P33 precipitated is measured with the Wallac Betacounter.
The measured data are evaluated using the standard Graphpad software (Levenburg-Marquard Algorhythmus).
Measurement of Cytotoxicity on Cultivated Human Tumour Cells
To measure cytotoxicity on cultivated human tumour cells, cells of cervical carcinoma tumour cell line HeLa S3 (obtained from American Type Culture Collection (ATCC)) are cultivated in Ham's F12 Medium (Life Technologies) and 10% foetal calf serum (Life Technologies) and harvested in the log growth phase. Then the HeLa S3 cells are placed in 96-well plates (Costar) at a density of 1000 cells per well and incubated overnight in an incubator (at 37° C. and 5% CO2), while on each plate 6 wells are filled with medium alone (3 wells as the medium control, 3 wells for incubation with reduced AlamarBlue reagent). The active substances are added to the cells in various concentrations (dissolved in DMSO; DMSO final concentration: 0.1%) (in each case as a triple measurement). After 72 hours incubation 20 μl AlamarBlue reagent (AccuMed International) are added to each well, and the cells are incubated for a further 7 hours. As a control, 20 μl reduced AlamarBlue reagent is added to each of 3 wells (AlamarBlue reagent, which is autoclaved for 30 min). After 7 h incubation the colour change of the AlamarBlue reagent in the individual wells is determined in a Perkin Elmer fluorescence spectrophotometer (excitation 530 nm, emission 590 nm, slits 15, integrate time 0.1). The amount of AlamarBlue reagent reacted represents the metabolic activity of the cells. The relative cell activity is calculated as a percentage of the control (HeLa S3 cells without inhibitor) and the active substance concentration which inhibits the cell activity by 50% (IC 50 ) is derived. The values are calculated from the average of three individual measurements—with correction of the dummy value (medium control).
FACS Analysis
Propidium iodide (PI) binds stoichiometrically to double-stranded DNA, and is thus suitable for determining the proportion of cells in the G1, S, and G2/M phase of the cell cycle on the basis of the cellular DNA content. Cells in the G0 and G1 phase have a diploid DNA content (2N), whereas cells in the G2 or mitosis phase have a 4N DNA content.
For PI staining, for example, 0.4 million HeLa S3 cells were seeded onto a 75 cm 2 cell culture flask, and after 24 h either 0.1% DMSO was added as control or the substance was added in various concentrations (in 0.1% DMSO). The cells were incubated for 24 h with the substance or with DMSO before the cells were washed 2× with PBS and then detached with trypsin/EDTA. The cells were centrifuged (1000 rpm, 5 min, 4° C.), and the cell pellet was washed 2× with PBS before the cells were resuspended in 0.1 ml PBS. Then the cells were fixed with 80% ethanol for 16 hours at 4° C. or alternatively for 2 hours at −20° C. The fixed cells were centrifuged (1000 rpm, 5 min, 4° C.), washed with PBS and then centrifuged again. The cell pellet was resuspended in 2 ml 0.25% Triton X-100 in PBS, and incubated on ice for 5 min before 5 ml PBS are added and the mixture is centrifuged again. The cell pellet was resuspended in 350 μl PI staining solution (0.1 mg/ml RNase A (Sigma, No. R-4875), 10 μg/ml prodium iodide (Sigma, No. P-4864) in 1×PBS). The cells were incubated for 20 min in the dark with the staining buffer before being transferred into sample measuring containers for the FACS scan. The DNA measurement was carried out in a Becton Dickinson FACS Analyzer, with an argon laser (500 mW, emission 488 nm), and the DNA Cell Quest Programme (BD). The logarithmic Pi fluorescence was determined with a band-pass filter (BP 585/42). The cell populations in the individual cell cycle phases were quantified using the ModFit LT Programme made by Becton Dickinson.
The compounds according to the invention were also tested accordingly on other tumour cells. For example, these compounds are effective on carcinomas of all kinds of tissue (e.g. breast (MCF7); colon (HCT116), head and neck (FaDu), lung (NCI-H460), pancreas (BxPC-3), prostate (DU145)), sarcomas (e.g. SK-UT-1 B, Saos-2), leukaemias and lymphomas (e.g. HL-60, Jurkat, THP-1) and other tumours (e.g. melanomas (BRO), gliomas (U-87MG)) and could be used for such indications. This is evidence of the broad applicability of the compounds according to the invention for the treatment of all kinds of tumour types.
The compounds of general formula (I) may be used on their own or in conjunction with other active substances according to the invention, optionally also in conjunction with other pharmacologically active substances. Suitable preparations include for example tablets, capsules, suppositories, solutions, —particularly solutions for injection (s.c., i.v., i.m.) and infusion—elixirs, emulsions or dispersible powders. The content of the pharmaceutically active compound(s) should be in the range from 0.1 to 90 wt.-%, preferably 0.5 to 50 wt.-% of the composition as a whole, i.e. in amounts which are sufficient to achieve the dosage range specified below. The doses specified may, if necessary, be given several times a day.
Suitable tablets may be obtained, for example, by mixing the active substance(s) with known excipients, for example inert diluents such as calcium carbonate, calcium phosphate or lactose, disintegrants such as corn starch or alginic acid, binders such as starch or gelatine, lubricants such as magnesium stearate or talc and/or agents for delaying release, such as carboxymethyl cellulose, cellulose acetate phthalate, or polyvinyl acetate. The tablets may also comprise several layers.
Coated tablets may be prepared accordingly by coating cores produced analogously to the tablets with substances normally used for tablet coatings, for example collidone or shellac, gum arabic, talc, titanium dioxide or sugar. To achieve delayed release or prevent incompatibilities the core may also consist of a number of layers. Similarly the tablet coating may consist of a number or layers to achieve delayed release, possibly using the excipients mentioned above for the tablets.
Syrups or elixirs containing the active substances or combinations thereof according to the invention may additionally contain a sweetener such as saccharine, cyclamate, glycerol or sugar and a flavour enhancer, e.g. a flavouring such as vanillin or orange extract. They may also contain suspension adjuvants or thickeners such as sodium carboxymethyl cellulose, wetting agents such as, for example, condensation products of fatty alcohols with ethylene oxide, or preservatives such as p-hydroxybenzoates.
Solutions for injection and infusion are prepared in the usual way, e.g. with the addition of isotonic agents, preservatives such as p-hydroxybenzoates, or stabilisers such as alkali metal salts of ethylenediamine tetraacetic acid, optionally using emulsifiers and/or dispersants, whilst if water is used as the diluent, for example, organic solvents may optionally be used as solvating agents or dissolving aids, and transferred into injection vials or ampoules or infusion bottles.
Capsules containing one or more active substances or combinations of active substances may for example be prepared by mixing the active substances with inert carriers such as lactose or sorbitol and packing them into gelatine capsules.
Suitable suppositories may be made for example by mixing with carriers provided for this purpose, such as neutral fats or polyethyleneglycol or the derivatives thereof.
Excipients which may be used include, for example, water, pharmaceutically acceptable organic solvents such as paraffins (e.g. petroleum fractions), vegetable oils (e.g. groundnut or sesame oil), mono- or polyfunctional alcohols (e.g. ethanol or glycerol), carriers such as e.g. natural mineral powders (e.g. kaolins, clays, talc, chalk), synthetic mineral powders (e.g. highly dispersed silicic acid and silicates), sugars (e.g. cane sugar, lactose and glucose) emulsifiers (e.g. lignin, spent sulphite liquors, methylcellulose, starch and polyvinylpyrrolidone) and lubricants (e.g. magnesium stearate, talc, stearic acid and sodium lauryl sulphate).
The preparations are administered by the usual methods, preferably by oral or transdermal route, most preferably by oral route. For oral administration the tablets may, of course contain, apart from the abovementioned carriers, additives such as sodium citrate, calcium carbonate and dicalcium phosphate together with various additives such as starch, preferably potato starch, gelatine and the like. Moreover, lubricants such as magnesium stearate, sodium lauryl sulphate and talc may be used at the same time for the tabletting process. In the case of aqueous suspensions the active substances may be combined with various flavour enhancers or colourings in addition to the excipients mentioned above.
For parenteral use, solutions of the active substances with suitable liquid carriers may be used.
The dosage for intravenous use is from 1-1000 mg per hour, preferably between 5 and 500 mg per hour.
However, it may sometimes be necessary to depart from the amounts specified, depending on the body weight, the route of administration, the individual response to the drug, the nature of its formulation and the time or interval over which the drug is administered. Thus, in some cases it may be sufficient to use less than the minimum dose given above, whereas in other cases the upper limit may have to be exceeded. When administering large amounts it may be advisable to divide them up into a number of smaller doses spread over the day.
The formulation examples which follow illustrate the present invention without restricting its scope:
EXAMPLES OF PHARMACEUTICAL FORMULATIONS
A) Tablets
per tablet
active substance
100
mg
lactose
140
mg
corn starch
240
mg
polyvinylpyrrolidone
15
mg
magnesium stearate
5
mg
500
mg
The finely ground active substance, lactose and some of the corn starch are mixed together. The mixture is screened, then moistened with a solution of polyvinylpyrrolidone in water, kneaded, wet-granulated and dried. The granules, the remaining corn starch and the magnesium stearate are screened and mixed together. The mixture is compressed to produce tablets of suitable shape and size.
B) Tablets
per tablet
active substance
80
mg
lactose
55
mg
corn starch
190
mg
microcrystalline cellulose
35
mg
polyvinylpyrrolidone
15
mg
sodium-carboxymethyl starch
23
mg
magnesium stearate
2
mg
400
mg
The finely ground active substance, some of the corn starch, lactose, microcrystalline cellulose and polyvinylpyrrolidone are mixed together, the mixture is screened and worked with the remaining corn starch and water to form a granulate which is dried and screened. The sodiumcarboxymethyl starch and the magnesium stearate are added and mixed in and the mixture is compressed to form tablets of a suitable size.
C) Ampoule solution
active substance
50
mg
sodium chloride
50
mg
water for inj.
5
ml
The active substance is dissolved in water at its own pH or optionally at pH 5.5 to 6.5 and sodium chloride is added to make it isotonic. The solution obtained is filtered free from pyrogens and the filtrate is transferred under aseptic conditions into ampoules which are then sterilised and sealed by fusion. The ampoules contain 5 mg, 25 mg and 50 mg of active substance.
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Disclosed are 6-formyl-tetrahydropteridines of the formula (I)
wherein the groups R 1 to R 6 have the meanings given in the claims and specification, the isomers thereof, methods of preparing these 6-formyl-tetrahydropteridines and their use as medicaments.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates generally to anti-corrosion fluid additives and, more particularly, but not by way of limitation, it relates to an improved form of composition for preventing corrosion to the metal parts of cooling systems and the like.
2. Description of the Prior Art
The prior art includes numerous types of anti-corrosion composition extending quite far back in the prior art. Some early approaches to radiator coolant additives included compounds which function both in an anti-corrosion and freezing point depressant manner. This teaching is exemplified by an early U.S. Pat. No. 1,405,320 which calls for an alkali metal chromate additive to an aqueous solution coolant. Later developments, as exemplified by U.S. Pat. No. 2,153,961, teach anti-corrosion protection through addition of a selected alkali metal chlorate to the various antifreeze liquids such as monohydric and polyhydric alcohols. In addition, prior inhibitors have utilized additives for specific metals such as nitrate, phosphates, sodium nitrite and related compounds. Later developments bringing environmental considerations negated use of certain additives, i.e., the potential explosivity of chlorates, the carcinogenous nature of nitrites, etc.
Further expansion of the art saw various other forms of anti-corrosive additive. U.S. Pat. No. 3,231,501 provides a composition for treatment of aqueous coolant with addition of borate salts. U.S. Pat. No. 3,639,263 utilized water-dispersable tannin along with specific sulfonate and inorganic metal salts. Thus, there has been prior teaching for a wide range of organic and inorganic materials for corrosion protection of the metal components of heating and cooling systems. Specific additives have been developed for protection of selected metals such as iron, copper, nickel, solder, etc.
SUMMARY OF THE INVENTION
The present invention relates to an improved form of anti-corrosion additive for fluids for use in such as cooling systems, the composition providing improved effective protection of all metallic or other components of a system while avoiding use of carcinogenic, potentially explosive, or materials having other damaging side effects. The composition in a preferred form consists essentially of a perchlorate salt for addition in selected concentration to a coolant liquid, and the composition may further consist of balanced addition of additional compounds directed to specific materials protection functions.
Therefore, it is an object of the present invention to provide an improved corrosion inhibition additive for cooling systems and the like.
It is also an object of the present invention to provide a corrosion inhibition additive that is more associative environmentally and exhibits least likelihood of carcinogenesis.
It is still further an object of the invention to provide an aqueous solution that provides more effective corrosion inhibition for iron and steel cooling system components as well as for the associated parts of other metals and alloys such as aluminum, copper, solder, etc.
It is another object of the invention to provide surface coating of circulation system components which extends corrosion inhibition in areas where cavitation of fluid flow may be present.
Finally, it is an object of the present invention to provide a user friendly additive composition for circulating system liquids which still provides maximum corrosion protection to the metal structural components.
Other objects and advantages of the invention will be evident from the following detailed description.
DESCRIPTION OF PREFERRED EMBODIMENTS
The present invention is directed to a corrosion and cavitation inhibition additive for use with cooling systems and the like for protecting the metal components of the system, particularly the iron and/or steel parts thereof. The additive composition may be used in any of the several coolant materials ranging from water through the various monohydric and polyhydric alcohol base liquids. In any case, the additive composition in aqueous solution serves to provide a protective coating for internal metal structures of the system, and a complete additive composition in accordance with the invention may render the system parts substantially free from all corrosion effects.
Basically, and in the presently preferred form, the primary additive to the coolant material is an alkali or alkaline earth salt of perchlorate. Most preferred is the sodium perchlorate salt, NaClO 4 .H 2 O, as added to the coolant solution in what is considered to be a wide range of concentration from on the order of 100 parts per million (ppm) up to much greater proportion. The solution is then buffered to a slight basic pH, as will be described. Generally then, addition of an aqueous solution of sodium perchlorate monohydrate, contributing sufficient perchlorate ion (ClO 4 - ) in solution, will provide highly effective and safe corrosion protection for iron and/or steel, copper and alloys, aluminum, etc., in the cooling systems of various engines for automobiles, trucks, buses, etc.; and, anti-corrosion perchlorate additive may also find use in larger applications such as ships cooling systems, residential and industrial cooling towers, and any circulating fluid system utilizing metal components in association. Other alkali and alkaline earth perchlorate salts may be similarly employed, cost being a primary consideration.
Corrosion breakdown on the surface of iron or steel system components begins with the formation of Fe 2 O 3 or as more commonly called, rust. This type of oxide coating exhibits an anti-protective character as it contributes continually to the corrosion process. The addition of perchlorate ion to the coolant liquid or solution causes iron or steel components in contact therewith to form a protective oxide coating. The perchlorate ion brings about a mixed oxidation state forming a surface ferrosoferric oxide (FeO.Fe 2 O 3 ), hereinafter referred to as Fe 3 O 4 . This alternate oxide of iron is non-corrosive and actually builds to form a shielding protective coat when used in sufficient concentration, e.g., greater than approximately 100 parts per million (ppm). In addition, presence of the perchlorate ion indicates such protective function and has no negative effects on other metals within the cooling system such as copper, brass, solder and the like, and these components may actually be afforded a still more positive protection by other solution additives, as will be further described below.
It has also been found that addition of the perchlorate ion provides highly effective corrosion protection in cooling system interior passages or flow ways where cavitation patterns may be set up. Thus, areas within cavitation bubble areas may be out of contact with actual anti-corrosive fluid materials; however, with the present invention, protection is still provided by the Fe 3 O 4 coating that is formed by the presence of the perchlorate ion. While severe pitting is formed on some iron and steel engine parts using prior art fluid corrosion inhibitors, especially along axes of vibration as in a cylinder liner, the perchlorate induced Fe 3 O 4 coating maintains a full protective shield.
In order also to afford maximum protection to associated aluminum parts of the cooling system, one may utilize further addition within a wide range of concentrations of sodium silicate in hydrate form (Na 2 SiO 3 .5H 2 O). Addition of the silicate ion (SiO 3 -2 ) in a concentration range including 460 ppm causes chemical reaction to coat the aluminum surface thereby to provide corrosion protection from circulating coolant. In addition to sodium silicate, a number of related silicate salts, meta and ortho-silicates and silicon esters may be added to provide the similar protective surface coating on aluminum structure.
Additional aluminum structure corrosion protection may be afforded by the addition of such as sodium nitrate which actively counteracts any tendency toward aluminum pitting and build-up of a fuzzy coating which tends to entrap and coagulate corrosion material that may cause localized corrosive effects over prolonged periods. Addition of the sodium nitrate or nitrate ion (NO 3 - ) to a minimal concentration on the order of 700 ppm will function to prevent pitting and fuzz coat build-up on aluminum; however, it should be understood that there is a wide range of concentrations of nitrate ion that may be utilized.
The pH value of the aqueous solution may be kept within a desired range by addition of a selected amount of buffer material such as borax (Na 2 B 4 O 7 .5H 2 O ). Thus, a relatively heavy concentration of buffer may be required to bring about desired pH value adjustment. Various other carbonates and phosphates may also be utilized for this purpose in well-known manner. A chelating agent such as sodium polyacrylate may be added in minor concentration of about 25 ppm to prevent hardness and undue coagulation of foreign materials in the cooling solution. Other chelating agents such as ethylenediaminetetraacetic acid (EDTA) or nitrilotriacetic acid (NTA) may be used in preselected effective concentration.
It may also be desirable to provide further protection for copper and brass components utilized in the cooling system. Thus, addition to the aqueous solution of commercial grade tolytriazole in a minimal concentration of about 200 ppm will afford such copper and brass corrosion protection. Solder connections and joints may be protected with addition of such as 2-mercaptobenzothiazole or any of the several alkali metal salts thereof. Addition of the solder protective agent to the desired concentration functions to effect formation of a protective film over the solder surface thereby to shield from contact with circulating coolant and any corrosive materials.
EXAMPLE A
Primary testing has been carried out for iron, steel, aluminum, brass and copper specimens in presence of a solution including the perchlorate ion. Thus, sodium perchlorate monohydrate in water solution in concentration of at least 100 ppm, with addition of sufficient borax to buffer the pH to a slight basic value of about 9, exhibits effective and rapid formation of the Fe 3 O 4 film on the iron and steel specimens thereby to provide corrosion protection. No deleterious effects were noted for the brass and copper specimens while the aluminum specimen showed slight pitting. Aluminum corrosion can be effectively combatted with further additives (silicates, nitrates) as set forth above.
EXAMPLE B
Basic corrosion protection of key system components was provided by mixing an aqueous coolant solution including perchlorate and nitrate. Thus, sodium perchlorate monohydrate contributes ClO 4 - ion in proportion of approximately 450 ppm, with sodium nitrate adding NO 3 - presence to approximately 700 ppm, thereby to inhibit corrosion of iron, steel, aluminum and solder in highly effective manner, as was noted in testing. Minimal corrosion loss was noted for brass and copper. Testing of the above low corrosion coolant was carried out in accordance with the required procedures of "Corrosion Test For Engine Coolants in Glassware" as set forth at pages 215-223 of ASTM American National Standards--1982, ANSI/ASTM D1384 (Reapproved 1975). Weight loss due to corrosion was minimal showing excellent protection for the component structural metal specimens.
EXAMPLE C
An aqueous solution of sodium perchlorate monohydrate and sodium nitrate, e.g. ClO 4 - at 450 ppm and NO 3 - at 720 ppm, was tested in accordance with the standard procedures for "Simulated Service Corrosion Testing of Engine Coolants" as set forth at pages 357-365 of ASTM American National Standards--1982, ASTM D2570-73. This test, simulating engine conditions and carried out at 190° Fahrenheit temperature, also exhibits to good degree the effectiveness of the perchlorate additive as a corrosion inhibitor in cooling systems, particularly with higher temperature coolants. Weight tally of metal specimens after 332 hours of continuous test indicate extremely good corrosion inhibition with zero weight loss for steel and losses on the order of 0.0005% to 0.001% for copper, brass and cast iron. Losses for aluminum and solder are also negligible and within acceptable limits; however, these metals may be still further protected with special additives as above described.
While the above recitation of additive concentrations are recited relatively precisely as was the case in specific tests, it should be understood that the active additive concentrations may vary within a wide range while still yielding effective anti-corrosion interaction. Thus, any of the perchlorate, silicate, nitrate, borate and other additives may be varied within wide limits of dry measure in constituting the selected additive composition.
EXAMPLE D
A complete form of corrosion inhibition solution which has proven to function to very good advantage may be formed with a specified measure as follows:
______________________________________sodium perchlorate monohydrate 0.635 grams per litersodium silicate 1.300 grams per litersodium nitrate 1.000 grams per litersodium borate (borax) 4.5 grams per litersodium polyacrylate 0.025 grams per litertolytriazole 0.200 grams per liter2-mercaptobenzothiazole 0.500 grams per literTOTAL 8.160 grams per liter______________________________________
The above composition provides a complete corrosion inhibition additive for protection of iron, steel, aluminum, copper, brass and solder while also providing buffering and chelating adjustment to the solution. Thus, while the primary perchlorate additive functions to protect the metal components, particularly iron and steel, the remaining additives selectively function to fulfill the complete corrosion protection process. Final selection of ingredients for a coolant solution may be dictated by presence or exclusion of certain metallic materials within the cooling system and in contact with the solution, and such adjustment may be varied in accordance with the exigencies of each particular cooling application. The additive may be prepared in dry measure for addition to water or other standard coolant materials, or liquid coolant solution may be prepared in entirety.
Another mode of introducing the perchlorate ion into the coolant solution is by use of a carrier such as anion ion exchange resin. For example, ion exchange resin such as A1O1-D or Al02-D, commercially available from Diamond Shamrock Co., may be processed to carry perchlorate ion for subsequent disposition directly into the coolant fluid. In this case the source may be perchloric acid as passed through a column of the ion exchange resin, and the charged resin may then be washed by strong basic solution such as NaOH, KOH into the coolant fluid at desired concentration. Again, the coolant should be buffered to adjust pH to slight basic.
It may also be desirable in certain coolant or circulating fluid applications to effect hardness control of the fluid. In this case, a commercially available cation-ion exchange resin, e.g. R-190 IONAC from Sybron Corp. of Birmingham, N.J., may be added to the solution for aiding in removal of calcium, magnesium, etc.
Changes may be made in the composition and concentration of materials as heretofore set forth in the specification; it being understood that changes may be made in the specific examples disclosed without departing from the spirit and scope of the invention as defined in the following claims.
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A method and composition for corrosion protection of metal components of a fluid circulation system utilizing a buffered solution containing perchlorate ion and specific operative additives.
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BACKGROUND OF THE INVENTION
1. FIELD OF THE INVENTION: This invention relates to a subsurface well tool for use in oil and gas wells, for use in injecting fluids into perforations within the well bore; more specifically, to a well tool mechanically set by manipulation of a tubing string, and providing for pressure equalization across packing elements on opposite sides of a perforation to facilitate release of the well tool.
2. DESCRIPTION OF THE PRIOR ART: It is often necessary to inject fluids, such as water, acid, or various types of chemicals, into an underground formation through perforations in the casing which provides for communication between the formation and the well bore. Most conventional injection tools can be used to inject fluids into the perforations contained within a specified interval of a well. Normally these tools require the use of two tools, one above the interval and one below the interval, connected together to permit fluid injection. Thus, a packer can be secured to a ported tubing section which is in turn secured to a lower packer, thus, providing isolation for the intermediate interval. However, these tools are suitable only for injecting fluids into intervals of six feet or greater. These tools generally are not suitable for injecting fluids into intervals as small as six inches, which may be desirable if fluids must be selectively injected into closely adjacent perforations. The conventional multipacker device is unsuitable for use in injecting fluids into such small intervals, because the mechanism necessary to set each packer renders it virtually impossible to position the packers closely adjacent each other.
One tool which can be used to inject fluids into a well is a modified version of the tool shown in U.S. Pat. No. Re. 25,639. As depicted in that patent, the packer shown therein would not be suitable for radial injection through the tubing string and out the mandrel. However, a radially extending mandrel port has been employed on tools similar to that shown in U.S. Pat. No. Re. 25,639 to accommodate such fluid injection
SUMMARY OF THE INVENTION
This invention relates to a tool for use in a well bore for producing hydrocarbons through a tubing string from a subterranean hydrocarbon-bearing formation. The tool includes a tubular body assembly, and, mounted on such assembly upper and lower packing elements, each suitable for sealing the annular area between tubing string and a casing or liner upon axial compression and radial expansion of the packing element. The packing elements can be set by longitudinal manipulation of a mandrel which can be attached to the tubing string and is insertable in the tubular body assembly. An injection path is established through a port in the mandrel between the bore of the mandrel and the exterior of the tool. An outer injection port communicating with the mandrel injection port is established in the tubular body assembly between the upper and lower packing elements. When a removable plug is positioned in the mandrel below the injection port, fluid can be injected through the mandrel and through a small interval between the upper and lower packing elements. A longitudinal bypass on the exterior of the tool mandrel provides a path for releasing annulus pressure acting on the expanded packing elements to permit the tools to retract. Seals are provided to seal this bypass until longitudinal movement of the mandrel shifts the seals to open the longitudinal bypass above and below the injection tool.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A through 1D comprise longitudinal continuations, vertical sectional views of the injection tool in its retracted configuration.
FIGS. 2D through 2D comprise longitudinal continuations, vertical sectional views of the injection tool positioned to inject fluids into the perforations in the casing communicating with a subterranean formation.
FIG. 3 is a schematic view illustrating the injection of fluids through the injection tool of FIGS. 2A through 2D into one of several closely adjacent formations.
FIG. 4A is a sectional view taken on the plane 4A--4A of FIG. 1D
FIG. 4B is a sectional view taken on the plane 4B--4B of FIG. 2D.
FIG. 5 is a perspective view of the drag block housing.
FIG. 6 is a sectional view taken on the plane 6--6 of FIG. 5.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
As seen in FIGS. 1A through 1D, the injection tool 2 includes a rigid mandrel assembly 4 which can be attached to a conventional tubing string extending between the surface of the well and the location of the injection tool. Conventional threads 4a located at the top of the mandrel 4 are used to secure mandrel assembly 4 to a tubing string. One means of securing the injection tool to the tubing string is a conventional coupling TC, as seen in FIG. 2A. Mandrel assembly 4 comprises a tubular structure having a mandrel bore extending therethrough communicable with the tubing string.
An upper unloader seal assembly including an annular elastomeric seal 14 is positioned adjacent the upper end of the mandrel 4. This upper unloader seal assembly comprises an upper seal retainer 6 secured to a lower seal retainer 8 by means of a threaded connection therebetween. A split ring retainer 10 held within an annular groove on the exterior of mandrel 4 engages the upper seal retainer member 6 and also engages a seal spacer 12. The retainer ring 10 and the seal spacer 12 are trapped between the upper seal retainer 6 and the lower seal retainer 8. Lower seal retainer 8 has a lower shoulder extending radially inwardly over a portion of the annular elastomeric upper seal ring 14 to hold the seal ring firmly secured around the exterior of mandrel 4.
Immediately below the upper seal assembly, including seal 14, the exterior of the mandrel 4 slopes inwardly to an outer diameter equivalent to that in section 4b. The outer diameter and thickness of the mandrel 4 remains essentially the same as shown at section 4b for that portion of the mandrel extending from the upper seal assembly to the lower end of the mandrel. A hydraulic hold-down housing 18 forming a portion of the exterior housing of the injection tool 2 extends around the upper portion of the mandrel section 4b and is attached by means of a threaded connection 18b to a cylindrical seal compressor 16. A rim 16a located at the upper end of seal compressor 16 has a reduced thickness and is opposed to the elastomeric seal 14. Seal compressor 16 is radially spaced from the exterior surface of mandrel section 4b by an amount sufficient to be radially coextensive with elastomeric seal 14.
A port 18a extends through the exterior of housing section 18 and communicates with a cavity formed between the outer housing section 18 and a balance sleeve 20. Conventional seals 19 and 21 establish sealing integrity with balance sleeve 20. The diameter of O-ring seal 19 and the surface which it engages is greater than the diameter of O-ring seal 21 and the surface which it engages, thus creating a net pressure area on balance sleeve 20. Balance sleeve 20 is spaced from the mandrel 4 below the seal compressor 16. In FIG. 1A, balance sleeve 20 is located in its uppermost position. The bottom end of balance sleeve 20 engages a radially outwardly protruding lug 4f forming a part of the exterior of mandrel 4. Hydraulic hold-down receptacle 22 is positioned on the interior of the outer housing 18 and is secured thereto by threads 18c located adjacent the upper end of the hydraulic hold-down receptacle 22. O-ring 21 is positioned within an inner groove on hydraulic hold-down receptacle 22 and a reduced diameter lower section 20a of balance sleeve 20 contacts the inner surface of hydraulic seal receptacle 22. The receptacle 22 constitutes the upper portion of what may be called the tubular body assembly of the tool.
The hydraulic seal receptacle 22 has a plurality of radially extending cylindrical apertures, each containing a hydraulic hold-down piston or button 26. In the preferred embodiment of this invention, a plurality of hold-down buttons are positioned circumferentially around the injection tool. As shown in FIGS. 1A and 1B, a pair 26a and 26b of hold-down buttons are positioned one above the other at each circumferential position. The hold-down buttons are shown in FIGS. 1A and 1B in their retracted position. A retainer bracket 24 secured to the receptacle 22 extends longitudinally over the exterior of each hold-down button 26. The retainer bracket 24 is secured to the receptacle or body 22 by a plurality of flat-head screws 30. A pair of springs 28a and 28b engages each of the hold-down buttons 26a and 26b at each circumferential location. The hold-down buttons 26a and 26b each have an O-ring 26c extending therearound engaging radial cylinders defined in receptacle 22. Each hold-down button or piston is cylindrical and has a longitudinally extending groove 26d for receiving springs 28 and through which the bracket 24 extends.
An upper intermediate housing or body section 32 is attached to the hydraulic hold-down seal receptacle 22 by a threaded connection 22d and an O-ring seal retainer 34 is in turn secured to hydraulic hold-down receptacle 22 by internal threads 22e with O-rings 33 and 35 establishing sealing integrity. An upper portion 36 of a longitudinally extending bypass area is defined on the interior of the upper intermediate housing or body 32 and extends between the mandrel 4 and the seal receptacle 22 upwardly through the balance sleeve 20 and through the seal compressor 16 to communicate with the exterior of the injection tool in the configuration shown in FIGS. 1A and 1B.
A packing element mandrel 42 having an opposing shoulder 42a engaging the lower end of upper intermediate housing 32 extends concentrically relative to the inner mandrel portion 4b from the lower end of housing 32. An annular gage ring 38 engages the exterior lower end of housing 32 and forms an upper abutment for the uppermost packing element 40a. Three packing elements 40a, 40b, and 40c, each of conventional annular construction, surround the packing element mandrel 42. Two packing elements separators 41 and 41 are positioned on opposite ends of the intermediate packing element 40b. The packing elements can comprise a conventional elastomeric material. If desired, the packing elements can be fabricated of elastomeric elements of different durometers. A lower gage ring 46 similar in construction to upper gage ring 38 is positioned in abutting relationship to the lower end of packing element 40c which comprises the lowermost of the upper set of three packing elements.
As shown in FIG. 1B, an inner injection port 4d extending through mandrel 4 establishes communication between the mandrel bore and the longitudinal bypass 36 formed around the exterior of mandrel 4. An outer ported section 48 (FIG. 1C) threadably secured at its upper end to gage ring 46 defines an exterior radial port 50 communicating between longitudinal bypass section 36 and the exterior of the tool immediately below the upper set of packing elements 40a, 40b, and 40c. The outer ported section 48 has an inner diameter which is greater than the inner diameter of the upper packing element mandrel 42 and which is also greater than the inner diameter of a lower packing element mandrel 58 secured to the lower end of the ported section 48 by threads 48a. Therefore the thickness of the longitudinal bypass longitudinally above and below the ported section 48 is less than the thickness of the bypass on the interior of ported section 48.
In the preferred embodiment of this invention, the inner mandrel 4 can comprise a plurality of threaded sections. A lower unloader seal support comprising a tubular metallic section 52 (FIG. 1C) having annular elastomeric sections 54 secured to the exterior thereof, is threadably secured between the sections 4b and 4c of mandrel 4. In the configuration shown in FIG. 1C, the lower unloader seals 54 can be positioned in the portion of the longitudinal bypass adjacent port 50. In this section of the longitudinal bypass, seals 54 do not engage an interior surface and the longitudinal bypass is continuous between the upper section 36 and a lower section 66.
Additionally, the unloader seal support 52 comprises a seal bore portion 52a immediately above a constricted bore portion 52b. The upwardly facing shoulder 4g thus defined provides a mounting for a wireline removable plug 94 having seal elements 94b and a fishing neck 94a. If desired, conventional locking type, wireline removable plug may be substituted for plug 94 which will facilitate selective swabbing of the perforations.
A gage ring 56 is secured to the lower end of ported section 48 by the threads 48b and abuts the upper end of the uppermost of three lower packing elements, 60a, 60b, and 60c. Each of these packing elements is conventional in nature and can be similar in construction to the corresponding packing elements 40a, 40b, and 40c located above the ported section 48. Similar packing elements separators 61a and 61b are located above and below the central packing element 60b of the lowermost set of three packing elements. These packing elements 60a, 60b, and 60c surround and engage the lower packing element mandrel 58 in the same manner that the upper packing elements 40a, 40b, and 40c engage the upper packing element mandrel 42. The lower section 66 of the longitudinal bypass extends between packing element mandrel 58 and the adjacent portion of the mandrel 4.
A lower gage ring 62 is secured by threads 62a to a tie sleeve 64 which comprises a cylindrical member defining the portion of the outer tool housing below packing elements 60. A radial port 68 extending through tie sleeve 64 establishes communication between the lower section 66 of the longitudinal bypass and the exterior of the tool.
An expander cone 70 is secured to the lower end of tie sleeve 64 by means of conventional threaded connection 70a. A rocker slip sleeve 72 is secured to the upper cone 70 by means of an annular snap ring 71. The rocker slip sleeve 72 has a plurality of grooves 72a located circumferentially therearound for receiving the inner portions of conventional rocker slips 74. Each of the several rocker slips 74 located circumferentially around the lower end of the injection tool is spring loaded relative to the lower end of the rocker slip sleeve 72 by a plurality of springs 76, which engage the inner surface of lower drag section 74b of the rocker slip. The rocker slip assembly, comprising a plurality of equally spaced rocker slips is held in position by a rocker slip retainer ring 75 located just above the rocker slip drag sections 74b. In the configuration shown in FIG. 1D, the springs 76 bias the lower section of the rocker slip outwardly so that drag section 74b is the outermost section of the injection tool.
The upper end 74a of each rocker slip 74 comprises a section having a serrated outer surface 74c and an inclined inner surface 74d opposed to a cooperable camming surface 70b on the lower end of cone 70. In the retracted configuration shown in FIGS. 1C and 1D, the rocker slips 74 are spaced from the cone 70. The lower end of the rocker slip 74 is captured by an outer lip 78a on sleeve 78 to hold the rocker slip 74 in the run-in position.
Sleeve 78 is secured to a cross-over sleeve 80 by conventional threads 78b. The cross-over sleeve 80 is in turn secured to a drag block segment retainer housing 82 (FIG. 5) by threaded connections 80a. A plurality of peripherally spaced, longitudinal dove-tailed recesses 82b are provided in housing 82 to respectively accomodate drag blocks 83 which are urged outwardly by springs 87.
At the lower end of the housing 82, an outer lock segment retainer 88 is secured by threaded connection 82a to lock segment housing 82. A lock segment 90 having teeth 90a on its inner surface and a dummy lock segment 91 having no teeth are retained within the lock segment housing 82 by the outer retainer 88. Coil springs 92 (FIGS. 4A and 4B) extend circumferentially around the grooves 82f in housing 82 and the lock segments 90 and 91 to hold the segments in a radially retracted position. The horizontal teeth 90a on the inner surface of lock segment 90 engage cooperating horizontal grooves 4e extending partially around the lower portion of the mandrel 4 (FIG. 4A) to prevent axial movement of mandrel 4 relative to the rest of the tool.
The mandrel 4 may thus be released from the lock segment by limited angular rotation. The limit to the rotation is provided by an axial tab 82d (FIG. 5) on the top end of drag block housing 82 which engages a key 85 which is secured in a longitudinal slot 4h in the periphery of the mandrel 4 by the cross over sleeve 80. If the opposite direction of rotation of mandrel 4 is desired to release the mandrel to set the packer, then it is only necessary to reverse the positions of threaded lock segment 90 with unthreaded lock segment 91. A bevel 82e on each axial edge of tab 82 forces key 85 into slot 4h and improves the reliability of the key.
At the lower end of the mandrel 4, threads 4h provide a means for securing the mandrel 4 to a portion of the tubing string extending below the injection tool 2.
FIG. 2 shows the actuation of the injection tool 2 to permit injection of fluids through a single selected set of perforations, without injecting into closely adjacent perforations axially spaced from the selected perforations by distances of as little as 6 inches. As shown in FIG. 3, the upper set of packing elements 40 can be positioned above the selected set of perforations P while the lower set of packing elements 60 can be positioned below this same selected set of perforations. Expansion of packing elements 40 and 60 will then seal the annulus above and below the selected set of perforations and isolate the annular area surrounding the selected set of perforations from closely adjacent perforations above and below.
To position the injection tool 2 as shown in FIGS. 2A, 2B, 2C, and 2D the tool is lowered into a position adjacent the selected perforations P, with the tool in the configuration shown in FIGS. 1A, 1B, 1C and 1D. The lock segment 90 engagement with grooves 4e (FIG. 4A) prevents expansion of slips 74 and of the packing elements 40 and 60. When the outer injection port 50 has been positioned adjacent a designated set of perforations P as shown in FIG. 2B, partial rotation of the tubing T in a previous selected direction releases mandrel 4 for axial movement relative to the lock segment 90. As the tubing T is rotated, the grooves 4e are disengaged from lock segment 90 (FIG. 4B) to permit downward movement of the mandrel 4. During the partial rotation of the mandrel 4, the drag block section 74b of the rocker slips 74 and drag blocks 83 engage the casing C to prevent rotation of the lock segment and the lock segment housing relative to the casing.
Downward movement of mandrel 4 relative to the rocker slips 74 brings the inclined surface 70b of expander cone 70 into engagement with the lower surface of the slip portion 74a of the rocker slips. Slip portion 74a is thus firmly wedged into engagement with the casing and the teeth bite into the casing and prevent further downward movement of rocker slip 74 relative to the casing. Continued downward movement of the mandrel 4, after the slips 74 are firmly wedged into engagement with the casing, is transmitted through the upper unloading assembly which is shifted downwardly into engagement with seal compressor 16. This downward movement of the mandrel 4 is transmitted through the retainer housing 18 and the hydraulic hold-down receptacle 22 to outer housing 32. Downward force applied to inner mandrel 4 is thus transmitted to packing elements 40 and 60, which are compressed by continued downward movement of the mandrel 4 relative to the now stationary lower housing section 64. Thus, the compressive force applied to the packing elements 40 and 60 causes radial expansion of the packing elements into engagement with the casing to seal the annulus between the tubing T and the casing C.
The injection tool 2 is now in position to inject fluids through the selected perforations P adjacent the outer injection port 50. If not positioned in the tool as it is run into the well, the removable plug 94 can be positioned in engagement with mandrel seat 4g by conventional means. The removable plug 94 shown here can be lowered into the well by wireline means. With the plug in place and in engagement with seat 4g, fluid injected through the tubing would pass through mandrel port 4d into the longitudinal bypass upper section 36 adjacent the outer injection port 50. During setting of the injection tool, the lower seals 54 will have been shifted into a position in engagement with the more restricted portion of the longitudinal bypass 66, as shown in FIG. 2C. Thus, fluid cannot pass through the longitudinal bypass past seals 54. Fluid injected through mandrel port 4d cannot communicate with the annulus above packing elements 40 through longitudinal bypass portion 36 because the upper unloader seal 14 is held in engagement with the seal compressor 16 by the downward force applied to the mandrel 4. The injection pressure is, however, communicated through longitudinal bypass portion 36 to the balance sleeve 20. A differential pressure force equal to the difference between the injection pressure within longitudinal bypass 36 and the pressure in the annulus acting on balance sleeve 20 through port 18a acts across an area between seals 19 and 21. This pressure force shifts the balance sleeve 20 downwardly, maintaining it in engagement with the mandrel lug 4c. Thus any force due to injection pressure exceeding annulus pressure will act through balance sleeve 20 downwardly on mandrel 4 to insure that the mandrel stays in its downwardly shifted position.
Pressure of fluid injected through mandrel 4 will not act upwardly on the outer portion of the injection tool to release the tool since this pressure will act through longitudinal bypass portion 36 on the hydraulic hold-down buttons 26a and 26b. This pressure will shift the buttons outwardly, compressing springs 28a and 28b. In the preferred embodiment of this invention, the hydraulic hold-down members have serrated teeth 26e and these teeth engage the casing to secure the injection tool against upward movement.
In the event the annulus pressure below lower packing element 66 were to exceed the annulus pressure above the tool, this pressure would be transmitted through the open bottom end of the lower portion 4c of the mandrel 4 through port 4d into the upper section of the longitudinal bypass 36. Of course, the removable plug 94 would be unseated by this excess pressure existing below the tool. Thus, in the event of a greater pressure below than above the tool, this pressure would be transmitted through longitudinal bypass section 36 to act on the hydraulic hold-down buttons 26a and 26b in the manner just described. Thus, the tool will not be unseated or forced to move up the well bore.
The injection tool is fully retrievable and is resetable within the well. Thus, the tool 2 could be repeatedly shifted from the location of perforations through which fluid has just been injected and can be repositioned with the outer injection port in proximity to other perforations. Normal injection proceedure would involve positioning the injection tool adjacent the lower set of perforations and then sequentially repositioning the injection tool to inject at each subsequent set of perforations above the first set of perforations. At each subsequent set of perforations, the mandrel merely needs to be lowered to set the slip 74 and packing elements 40 and 60 as previously described. When the tool is shifted upwardly, the mandrel is moved in an upward direction. Thus, the compressive force supplied by the mandrel 4 to the packing elements 40 and 60 would be released and the cone 70 can be moved from beneath the slip portion 74a of the rocker slip 74.
The packing elements 40 and 60 would not tend to remain in their expanded configurations due to any pressure differential acting in the annulus across either set of packing elements. Upward movement of mandrel 4 will equalize the pressure across upper packing elements 40 by establishing communication between the annulus above the injection tool through longitudinal bypass section 36 and through the injection port 50 to the annulus below packing elements 40. Movement of the unloader seal 14 out of engagement with seal compressor 16, serves to establish such pressure equalization and pressure communication. After pressure is equalized across upper packing elements 40, as a result of movement of unloader seal 14 away from seal compressor 16, any pressure differential existing across packing element 60 can be relieved as the lower unloader seal 54 moves from within the restriction in lower bypass section 66 to the larger diameter portion proximate to outer injection port 50. A pressure equalization path is then established from the annulus below the packing element 60 through port 68, through the lower longitudinal bypass portion 66, through the injection port 50 to the annulus above lower packing element 60. This tool therefore provides an easily repeatable releasing procedure in which the mandrel 4 is merely manipulated in a longitudinal fashion to both release the packing elements 40 and 60 and the slips 74 and to equalize pressure across both sets of packing elements 40 and 60.
Lastly, the mandrel 4 may be partially rotated to re-engage grooves 4e with lock segment 90, thus permitting lowering of all the components of the tool to a new lower position.
Although the invention has been described in terms of a specified embodiment which is set forth in detail, it should be understood that this is by illustration only and that the invention is not necessarily limited thereto, since alternative embodiments and operating techniques will become apparent to those skilled in the art in view of the disclosure. Accordingly, modifications are contemplated which can be made without departing from the spirit of the described invention.
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An injection tool for use in injecting fluids through perforations in the well bore of an oil or gas well is mechanically set and mechanically releasable. Fluid can be injected between upper and lower packing elements into a selected perforation. The upper and lower packing elements on opposite sides of the perforation into which fluid is injected are retractable, and any pressure differential across the upper packing elements or across the lower packing elements can be separately equalized.
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DOMESTIC PRIORITY INFORMATION
This is a continuation application of application Ser. No. 11/081,642, filed Mar. 17, 2005, the entire contents of which are hereby incorporated by reference.
This application claims the benefit of the U.S. Provisional Application No. 60/553,961, filed on Mar. 18, 2004, in the name of inventor Yong Cheol PARK, entitled “Segment scope definition related with replaced defective cluster”, which is hereby incorporated by reference as if fully set forth herein.
FOREIGN PRIORITY INFORMATION
This application claims the benefit of the Korean Application No. 10-2004-0039143, filed on May 31, 2004, and Korean Application No. 10-2004-0039144, filed on May 31, 2004, which are hereby incorporated by reference as if fully set forth herein.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a high density optical disc, and more particularly, to an apparatus and method for recording and/or reproducing data to/from a recording medium.
2. Discussion of the Related Art
Optical discs are widely used for recording a large quantity of data. Among such optical discs, new high density optical media (HD-DVD), such as the Blu-ray Disc (hereinafter referred to as “BD”) are under development, which enable long time recording and storing of high definition video and audio data. Currently, a global standard technical specification of the Blu-ray disc, which is considered to be a next generation HD-DVD technology as a data storing solution that significantly surpasses the present DVD, is under development along with other digital apparatuses.
Accordingly, various draft standards related to the BD is under preparation, and in succession to a rewritable Blu-ray disc (BD-RE), various draft standards both for Blu-ray disc writable once (BD-WO), and Blu-ray disc read only (BD-ROM) are also under development. In such course of standardization process, as a method for recording and/or reproducing the BD-RE/R/ROM, recently a physical access control (PAC) method has been under discussion for solving problems caused by a failure of a drive, which supports an existing version, in supporting a new version when it is intended to introduce new functions for the BD-RE/R/ROM into the new version.
SUMMARY OF THE INVENTION
Accordingly, the present invention is directed to an apparatus and method for recording and/or reproducing data to/from a recording medium that substantially obviate one or more problems due to limitations and disadvantages of the related art.
A recording medium having a data area with a segment region and a replacement region. A first control data area storing access control information is used for controlling access to the segment region and a second control data area storing defect control information is used for controlling a defective region of the recording medium, replacing a data of the defective region to the replacement region. The replacement region corresponding to the defective region of the segment region is handled as the segment region to the access control information.
A method of recording to and/or reproducing from a recording medium. The process includes recording and/or reproducing access control information for controlling an access to a segment region in a user data area and defect control information including data of a defective region and a replacement region corresponding to the defective region. Then, controlling recording to and/or reproducing from the segment region according to the access control information, if the access control information is unknown one.
Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objectives and other advantages of the invention may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.
In another aspect, the exemplary embodiment also includes a recording medium having a data structure for managing a data area of the recording medium including at least one physical access control (PAC) cluster, the at least one PAC cluster including information for managing recording to and/or reproducing from the recording medium, wherein each PAC cluster includes a PAC header, common to each PAC cluster, and a PAC specific information area, which includes information specific to each PAC cluster, wherein the PAC header includes a segment information identifying at least one segment area in a user data area of the recording medium by a position information of the each segment area.
In another aspect, the exemplary embodiment also includes a method for recording or reproducing data on a recording medium including recording or reproducing at least one physical access control (PAC) cluster, the at least one PAC cluster including information for managing recording to and/or reproducing from the recording medium, each PAC cluster including segment information, if a PAC cluster is an unknown one and the segment information identifies at least one segment area in a user data area of the recording medium, recording to and/or reproducing from the at least one segment area by the PAC information, and if a defective area in the at least one segment area is replaced with a replacement area on a spare area of the recording medium, recording to and/or recording from the replacement area of the spare area by the PAC information.
Another aspect of the exemplary embodiment includes a method for recording and/or reproducing data to/from a recording medium in response to a command from a host, a method for recording and/or reproducing data to/from a recording medium includes storing management information including PAC information read from the recording medium, determining a PAC_ID in the PAC information, and recording and/or reproducing data in accordance with unknown PAC rules and segment information recorded on the PAC, if the determined PAC_ID is not sensible, and if a defective area is encountered in a segment area of the segment information during the determining a PAC_ID and recording and/or reproducing data, sensing information on a replacement area written thereon in replacement of the defective area as a defect list (DFL) information in a defect management area (DMA), and managing the replacement area identically as the segment area belonging to the defective area.
In a further aspect of the present invention, an apparatus for recording and/or reproducing data to/from a recording medium includes a memory for storing PAC information read from the recording medium, and a microcomputer for determining a PAC_ID in the PAC information, and recording/reproducing data in accordance with unknown PAC rules and segment information recorded on the PAC, if the determined PAC_ID is not sensible, and if a defective area is encountered in a segment area of the segment information during the determining a PAC_ID and recording and/or reproducing data, sensing information on a replacement area written thereon in replacement of the defective area from defect list (DFL) information in a defect management area (DMA), and managing the replacement area identically as the segment area belonging to the defective area.
It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiments of the invention and together with the description serve to explain the principle of the invention. In the drawings:
FIG. 1 illustrates physical access control (PAC) zones on a high density optical disc according to the present invention;
FIG. 2 illustrates configurations of INFO2 zone and INFO1 zone on the high density optical disc according to the present invention;
FIG. 3 illustrates a PAC recorded on the high density optical disc according to the present invention;
FIG. 4 illustrates a structure of a PAC on the high density optical disc according to the present invention;
FIG. 5 illustrates a configuration of an “Unknown PAC Rules” field according to the present invention;
FIG. 6 illustrates segment zones on the high density optical disc according to the present invention;
FIG. 7 illustrates a PAC method of the high density optical disc according to the present invention;
FIG. 8 illustrates a method for recording segment position information on the high density optical disc according to the present invention; and
FIG. 9 illustrates a block diagram of an optical recording and/or reproducing apparatus according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. In addition, although the terms used in the present invention are selected from generally known and used terms, some of the terms mentioned in the description of the present invention have been selected by the applicant at his or her discretion, the detailed meanings of which are described in relevant parts of the description herein. Furthermore, it is required that the present invention is understood, not simply by the actual terms used but by the meaning of each term lying within.
FIG. 1 illustrates PAC zones on a high density optical disc according to the present invention. Referring to FIG. 1 , the high density optical disc is sectioned and designated as, from an inner circumference to an outer circumference, a lead-in zone, a data zone, and a lead-out zone. At a fore end and rear end of the data zone, there may be an inner spare area (hereinafter referred to as “ISA”) and an outer spare area (hereinafter referred to as “OSA”), respectively. The spare areas ISA and OSA are areas for re-allocation of data to be written on a defective area thereto, when the defective area occurs in the data zone. The lead-in zone is sectioned, and designated as an INFO2 zone and an INFO1 zone for recording various kinds of information thereon. The INFO2 zone and an INFO1 zone have physical access control (PAC) zones, respectively.
For simplicity, the PAC zone assigned to the INFO2 zone is referred to as a PAC2 zone, and the PAC zone assigned to the INFO1 zone is referred to as a PAC1 zone. One of the PAC2 zone and the PAC1 zone has an original PAC recorded thereon, and the other one is a back-up zone for recording a copy of the original PAC. In view of a direction of writing from the inner circumference to the outer circumference of the disc, it is preferable that the original PAC is recorded on the PAC2 zone, and the back-up PAC is recorded on the PAC1 zone. The PAC zone, provided for solving the problems liable to happen when an old version drive fails to detect functions on the disc added from a new version of drive, has an “unknown rule”.
The “unknown rule” has rules defined thereon for controlling predictable operations of the disc, i.e., controls starting from basic control of read, write, and the like to linear replacement of a defective zone, logical overwrite, and the like. Accordingly, an area is provided on the disc where the “unknown rule” is applicable thereto, having segments for defining an entire disc, or a certain portion of the disc, which will be described in more detail in a later process. Thus, by defining an area to which the old version drive has access by using the “unknown rule”, the new version of optical disc reduces unnecessary access operation of the old version drive.
Moreover, by defining an accessible area on a physical area of the disc for the old version drive to access by using the PAC, a data area having a user data recorded thereon can be protected more robustly, and improper access from an outside of the disc, such as hacking, can be protected. In the meantime, the INFO2 zone and the INFO1 zone having the PAC2 and PAC1 zones therein in the lead-in zone will be reviewed in view of writable characteristics of the high density optical disc.
FIG. 2 illustrates configurations of the INFO2 zone and the INFO1 zone on the high density optical disc according to the present invention. Referring to FIG. 2 , in case of BD-RE of the high density optical disc, the INFO2 zone has 256 clusters including 32 clusters of PAC2 zone, 32 clusters of defect management area (DMA) 2 zone for management of defects, 32 clusters of control data (CD) 2 zone having control information recorded thereon, and 32 clusters of buffer zone (BZ) 3 zone of a buffer zone. The INFO1 zone includes 32 clusters of BZ2 zone of a buffer area, 32 clusters of drive area which is a drive area for storing specific information specific to a drive, 32 clusters of DMA1 zone for managing defects, 32 clusters of CD1 zone for recording control information, and BZ1-PACI zone for utilizing as the PAC zone.
In case of the high density optical disc of writable once (BD-R), the INFO2 zone has 256 clusters including a PAC2 zone, a DMA 2 zone, a CD 2 zone, and a BZ 3 zone, each with 32 clusters, and the INFO1 zone includes a BZ2 zone, a DMA1 zone, a CD1 zone, and BZ1-PACI zone, each with 32 clusters, and 128 clusters of drive area. Thus, the PAC zones of the present invention are assigned to the INFO2 zone and the INFO1 zone in the lead-in zone by 32 clusters respectively according to rewritable characteristics of the high density optical disc. In the PAC zone of 32 clusters, one PAC has one cluster. A structure in which one PAC is recorded at a size of one cluster will be described with reference to FIG. 3 .
FIG. 3 illustrates a structure of a PAC recorded on the high density optical disc according to the present invention. Referring to FIG. 3 , one PAC of one cluster size (32 sectors) includes a header zone, and a specific information zone specific to an optical disc drive. The PAC header zone has 384 bytes allocated to a first sector of the PAC, for recording various kinds of PAC information, such as information on an “unknown PAC rule” and segments, and the other area of the PAC zone has specific information specific to the optical disc drive which is called “known rule” recorded thereon.
A detailed structure of the PAC recorded in above structure will be described with reference to FIG. 4 . For simplicity, in the description of the present invention, particular fields of the PAC that require more detailed description will refer to drawings that illustrate the fields. FIG. 4 illustrates a structure of a PAC on the high density optical disc according to the present invention. Referring to FIG. 4 , as described above, the PAC includes a header portion applicable to all PACs, and an area having specific information specific to the drive recorded thereon.
In turn, the header portion includes 4 bytes of “PAC_ID”, 4 bytes of “Unknown PAC Rules”, 1 byte of “Entire Disc Flag”, 1 byte of “Number of Segments”, and 32 segments “Segment_ 0 ˜Segment_ 31 ” each with 8 bytes. The “PAC_ID” is a field for providing the present PAC status and identification codes, wherein if the “PAC_ID” has ‘00 00 00 00’ bits, the “PAC_ID” indicates that the present PAC is not used, if the “PAC_ID” has ‘FF FF FF FE’ bits, the “PAC_ID” indicates that the present PAC zone is not available for use due to reasons of defects or the like, and if the “PAC_ID” has ‘FF FF FF FF’ bits, the “PAC_ID” indicates that the present PAC zone is available for use again even if the PAC zone is used in the past.
Moreover, by recording the “PAC_ID” in bits agreed beforehand, such as ‘54 53 54 00’ bits, the “PAC_ID” is used as a code for determining if the disc is one that the present drive can make free access. More specifically, if the present drive does not know the “PAC_ID” applied thus, determining that this is a case when the present drive cannot understand the present PAC under a reason of version mismatch, or the like, the ‘54 53 54 00’ bits are used as a code requiring reference to information recorded on the “Unknown PAC Rules” field. As described above, the “Unknown PAC Rules” field is used as a field that designates an operation range of the drive that cannot understand the present PAC, which will be described with reference to FIG. 5 .
FIG. 5 illustrates a configuration of an “Unknown PAC Rules” field according to the present invention. Referring to FIG. 5 , definition of controllability of various areas on the disc is enabled by the “Unknown PAC Rules”. The “Area” on the table represents the controllable areas on the disc, the “Control” represents control types, such as read/write and so on, and “Number of bits” represents a number of bits required for the control. The additional bits in the “Number of bits” represent cases of dual layer disc with two recording/reproduction sides. For example, read/write controllability of the PAC zone can be represented with “PAC zones 1, 2” fields, and write controllability of defect management zone can be represented with “DMA Zone 1, 2” fields. Write controllability of a replacement area for a defective area can be represented with a “Replacement Clusters” field, read/write controllability of a data zone can be represent with a “Data Zone” field, and logical overwrite controllability can be represented with a “Logical Overwrite” field.
Evidently, the write controllability is physically applicable only to re-writable discs BD-RE, and BD-R, and, also the write controllability of a replacement area for a defective area is also applicable to the re-writable discs BD-RE, and BD-R. Thus, it is required to understand that the subject matter of the present invention is dependent on the re-writable characteristics of the high density optical disc. By using the above described method, the “Unknown PAC Rules” field enables designation of a controllable area on the disc for the drive of version mismatch. Moreover, above method is applicable, not only to the drive of version mismatch, but also to control of access to a particular physical area on a disc at a user's option.
In the meantime, the “Entire Disc Flag” field in FIG. 4 is used as a field for informing that the PAC is applicable to an entire area of the disc, and the “Number of Segments” field is a field representing a number of segment area the PAC is applicable thereto. Maximum 32 segments can be allocated to one PAC, and information on the allocated segments is written on fields of “Segment_ 0 ” to “Segment_ 31 ” each with 8 bytes. Each of the “Segment_ 0 ˜Segment_ 31 ” fields has the first PSN and the last PSN of the allocated segment area recorded thereon.
The segment will be described in more detail with reference to the accompanying drawings. FIG. 6 illustrates segment zones on the high density optical disc according to the present invention. Referring to FIG. 6 , if required, there can be maximum 32 segment areas on the high density optical disc of the present invention, for applying the PAC thereto starting from “Segment_ 0 ” in succession. In this case, by writing the first PSN which indicates a starting position of the allocated segment area, and the last PSN which indicates the last position of the allocated segment area on “Segment” fields of PAC2 and PAC1 zones, the optical disc drive is made to know positions of the segment areas. None of the plurality of allocated segments overlap, and the starting and last positions are designated at boundaries of clusters.
When a defective area occurs in the segment area allocated, in other words, in case of a writable high density optical disc BD-RE, or WO, a data to be recorded on the defective area is recorded on a replacement area, such as a spare area. In the present invention, the replacement area is also defined as an area belonging to the segment area, which will be described with reference to the attached drawings.
FIG. 7 illustrates a diagram showing a PAC method of the high density optical disc according to the present invention. Referring to FIG. 7 , with regard to the segment area having the PAC of the present invention applied thereto, if the defective area “A” occurs at the segment area, a data to be written on the defective area “A” is written on the spare area ISA or OSA in replacement, and information on the replacement is written on a defect management area (DMA) in the lead-in zone as a defect list (DFL) entry. The DFL entry includes “Status 1” and “Status 2” fields, for recording information on types of the DFL entries, a “Defective Cluster first PSN” field for recording a first physical sector number of a defective cluster, and “Replacement Cluster first PSN” for recording a first physical sector number of replacement cluster.
The “Status 1” field has a ‘0000’ bit recorded thereon for indicating that the defective area is of a RAD (Re-Allocatable Defect) type in which the defective area is replaced normally, the “Defective Cluster first PSN” field has ‘a’, the first PSN of the defective area, recorded thereon, the “Status 2” field has a ‘0000’ bit recorded thereon for indicating that the “Status 2” field is not used in the case of the writable high density optical disc (in case of the high density optical disc of writable once, the bit is used for indicating that one cluster has a defect), and the “Replacement Cluster first PSN” field has ‘b’ recorded thereon, which is the first physical sector number of the replacement area. In this case, since only one time of writing is physically possible in the high density optical disc of writable once (WO), it is preferable that the data to be written on the defective area is recorded on a temporary disc management area (TDMA) on the disc separate from the DMA area as a temporary defect list (TDFL) having a structure the same with the DFL entry at first, and is written on DMA area as the DFL when the user requires, or after a disc closing at the time of writing completion.
In the present invention, the replacement area ‘B’ where the data to be written on the defective area ‘A’ is written thereon in replacement is defined as the replacement area ‘B’ belongs to the segment the defective area ‘A’ belongs by using the DFL entry. Since this method enables to dispense with the requirement for handling the replacement area ‘B’ as a separate segment, waste of the segment areas a number of which is limited to 32 is prevented, and effective segment management by using the PAC is made possible. Thus, though the preferred embodiment of the present invention is described by taking a RAD type as an example, in which replacement of the defective area is made within one cluster, it is apparent in a case of a consecutive re-allocatable defect (CRD) type in which defective areas occurred at a plurality of consecutive clusters are replaced that the defective area is managed in a fashion identical to the segment area the defective area belongs thereto.
In the meantime, referring to FIG. 7 , the PAC in the lead-out zone, a duplicate of the PAC of an original PAC, is recorded for more robust protection of the PAC, and is recorded in an INFO zone of the lead-out zone. As described above, the position information on the segment area recorded on the “Segment” field by using a segment entry has the first PSN and the last PSN each with 32 bits. In this instance, the position information on the segment area recorded on the “Segment” field may not be represented with the first PSN and the last PSN, but with physical sector numbers of clusters taking an actual recording unit on the optical disc is clusters into account, which will be described with reference to FIG. 8 .
FIG. 8 illustrates a method for recording segment position information on the high density optical disc according to the present invention. Referring to FIG. 8 , with regard to the plurality of segment areas managed by the PAC, a segment entry having position information of each of the segment areas includes the “first PSN of the first cluster in the Segment” field and the “first PSN of the last cluster in the Segment” field. More specifically, as described above, since the optical disc is written in cluster units, a position of the segment area is represented in cluster units, with the first physical sector number of the first cluster of the segment and the first physical sector number of the last cluster of the segment. This method is convenient in view of firmware for operation of the drive.
FIG. 9 illustrates a block diagram of an optical recording and/or reproducing apparatus according to the present invention. Referring to FIG. 9 , the optical recording and/or reproducing apparatus includes a recording/reproducing device 10 for performing recording/reproduction on the optical disc, and a host, or controller 20 for controlling the recording/reproducing device 10 . (Herein, the recording/reproducing device 10 is often referred to as an “optical disc drive”, and both terms will be used in the description of the present invention).
More specifically, the host 20 gives a writing or reproduction order to write or reproduce to/from a particular area of the optical disc to the recording/reproducing device 10 , and the recording/reproducing device 10 performs the recording/reproduction to/from the particular area in response to the order from the host 20 . The recording/reproducing device 10 includes an interface unit 12 for performing communication, such as exchange of data and order, with the host 20 , a pickup unit 11 for writing/reading a data to/from the optical disc directly, a data processor 13 for receiving signal from the pickup unit 11 , and recovering a desired signal value, or modulating a signal to be written into a signal able to be written on the optical disc, and forwarding, a servo unit 14 for controlling the pickup unit 11 to read a signal from the optical disc accurately, or write a signal on the optical disc accurately, a memory 15 for temporary storage of various kinds of information including management information, and data, and a microcomputer 16 for controlling various parts of the recording/reproducing device 10 .
A method for recording a PAC on a high density writable optical disc by using the optical recording and/or reproducing apparatus will now be described. Upon inserting the optical disc into the optical recording and/or reproducing apparatus, all management information is read from the optical disc and stored in the memory of the recording/reproducing device 10 , for use at the time of recording/reproduction of the optical disc. Herein, if the user desires to write on a particular area of the optical disc, the host 20 , which consider such desire of the user as a writing order, provides information on a desired writing position to the recording/reproducing device 10 , along with a set of data that is to be written.
Then, the microcomputer 16 in the recording/reproducing device 10 receives the writing order, determines if the area of the optical disc in which the host 20 desires to write is a defective area or not from the management information stored in the memory 15 , and performs data writing according to the writing order from the host 20 on an area which is not the defective area. In this case, if it is determined that the writing on an entire disc or on the particular area includes new features which a related art recording/reproducing device is not provided with, leading the related art recording/reproducing device to fail to sense, or if it is intended to restrict functions, such as writing or reproducing to/from the particular area of the disc according to requirements requested by the user, the microcomputer 16 of the recording/reproducing device 10 writes control information of the area on the PAC zone on the disc as “Unknown PAC rule”. The microcomputer 16 of the recording/reproducing device 10 also writes PAC information, such as the PAC_ID for a written state, and segment information which is control information on the particular area of the disc.
If a defective area occurs at the segment area, by writing the data to be written on the defective area on a replacement area, such as the spare area, and the like, and information on this on the DMA area as a DFL entry, it is defined that the replacement area belongs to the segment area to which the defective area belongs. Moreover, the position of the segment area may be indicated with the first PSN and the last PSN of the cluster, or the first PSN of the first cluster and the last PSN of the last cluster of the segment in cluster units. Accordingly, the microcomputer 16 provides position information of the area the data is written thereon, or the PAC zone, and the data to the servo unit 14 and the data processor 13 , so that the writing is finished at a desired position on the optical disc through the pickup unit 11 .
In the meantime, a method for recording and/or reproducing the high density optical disc having the PAC information written by above method will be described. Upon inserting an optical disc into the optical recording and/or reproducing apparatus, all management information is read from the optical disc, and stored in the memory of the recording and reproducing device 15 , for use at the time of recording and reproduction of the optical disc. The information in the memory 10 includes position information of various zones inclusive of the PAC zone on the disc. Then, a PAC_ID field of the PAC is examined, for verifying if the PAC_ID of the PAC of the PAC zone is a sensible PAC_ID. As a result of the verification, if the written PAC_ID is sensible, determining that it is a case when the recording and reproducing device having written the data on the disc has a version identical to a version of the present recording and reproducing device, or a case when there is no separate writing/reproduction restrictions, the recording/reproduction is performed according to the order from the host 20 .
When the sensing of a code written on the PAC_ID fails, determining that it is a case when there are restrictions due to reasons, such as the recording and reproducing device having written the data on the disc has a version different from a version of the present recording and reproducing device, the recording/reproduction is preformed according to the order from the host with reference to recording/reproduction restriction areas on the disc written on the “Unknown PAC rule” and “Segment”. In this case, if there is a defective area in the segment area recorded on the “Segment”, and a data to be written is written on a replacement area by the DFL information written on the DMA area, the data on the replacement area is determined to be the segment area, the recording/reproducing is performed according to restriction of setting of recording/reproducing of the segment area. For this, the microcomputer 16 provides the position information and data according to the order of the host to the servo unit 14 and the data-processor 13 , so that the recording/reproduction is finished at a desired position on the optical disc through the pickup unit 11 .
The method and apparatus for recording and/or reproducing data to/from the recording medium have the following advantages. The definition of an accessible area of a disc of a related art version drive by using PACs permits robust protection of a data area having a user data recorded thereon, to cut off improper external access from a hacker or the like. Also, the PAC which manages entire data zone or the segment areas on the disc permits effective data recording and reproducing to/from the high density optical disc. In addition, a method for handling a case when a defect occurs at a segment area on the disc managed by the PAC is suggested, to permit an effective data recording and reproducing to/from the high density optical disc. And, finally, by recording position information of the segment area on the disc managed by the PAC in clusters, it is convenient in view of firmware for operation of the drive.
It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the inventions. Thus, it is intended that the present invention covers the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.
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A recording medium, comprising a data area including a segment region and a replacement region; a first control data area storing access control information for controlling access to the segment region; and a second control data area storing defect control information for controlling a defective region of the recording medium, replacing a data of the defective region to the replacement region, wherein the replacement region corresponding to the defective region of the segment region is handled as the segment region to the access control information.
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BACKGROUND OF THE INVENTION
[0001] Field of the Invention
[0002] The invention relates to a charge trapping memory cell or charge trapping gate memory cell for nonvolatile information storage, a semiconductor memory device having a plurality of memory cells for nonvolatile information storage, and a method for fabricating a charge trapping memory cell for nonvolatile information storage.
[0003] In the further development of semiconductor memory devices based upon nonvolatile memory mechanisms, the principle of the so-called nonvolatile charge trapping memory cell or charge trapping gate memory cell has also been developed. Such a charge trapping memory cell for nonvolatile information storage has a charge trapping gate configuration or charge trapping region configuration, a source/drain configuration and a control gate configuration. The charge trapping gate configuration or charge trapping region configuration serves for the actual information storage, while the source/drain configuration is configured for access to the charge trapping gate configuration or charge trapping region configuration and, thus, for access to the respective information. The control gate configuration is configured for controlling this access to the charge trapping gate configuration or charge trapping region configuration and to the information.
[0004] In the narrower sense of the invention, the charge trapping gate is understood to be a charge trapping region or charge trapping material region, that is to say, a region, e.g., a layer, made of a material that can form charge trapping states. Hereinafter, for the sake of brevity, the term charge trapping gate is used in this sense unless stated otherwise. Accordingly, the terms charge trapping gate, charge trapping region, and, if appropriate, charge trapping layer are used synonymously in the sense of the invention. In the broader sense, charge trapping gate means the configuration of charge trapping region, if appropriate, insulation region and control gate.
[0005] What is disadvantageous in the case of prior art semiconductor memory devices, memory cells contained therein and corresponding fabrication methods for semiconductor memory devices or memory cells is that their fundamental concept, from a structural and production engineering standpoint, is based on the provision of a single binary information unit in each individual memory cell. Each memory cell and, thus, each memory location are, thus, occupied only singly with information and configured accordingly.
SUMMARY OF THE INVENTION
[0006] It is accordingly an object of the invention to provide a charge trapping memory cell, method for fabricating it and semiconductor memory device that overcome the hereinafore-mentioned disadvantages of the heretofore-known devices and methods of this general type and that by which, in a particularly simple manner, a particularly high information density can be obtained and can be modified and retrieved in a particularly reliable manner.
[0007] With the foregoing and other objects in view, there is provided, in accordance with the invention, a charge trapping memory cell for nonvolatile storage of information including at least one of information units and binary bits, including a charge trapping gate configuration for storing the information, the charge trapping gate configuration having charge trapping gates each substantially independently storing the information and, as a result, storing a corresponding plurality of one of the information units and binary bits independently of one another in the memory cell, a source/drain configuration accessing the charge trapping gate configuration, and a control gate configuration controlling access to the charge trapping gate configuration.
[0008] With the objects of the invention in view, there is also provided a charge trapping memory cell for nonvolatile storage of information including at least one of information units and binary bits, including a charge trapping gate configuration for storing the information, the charge trapping gate configuration having charge trapping gates each substantially independently storing the information and, as a result, storing a corresponding plurality of one of the information units and binary bits independently of one another in the memory cell, a source/drain configuration connected to the charge trapping gate configuration and accessing the charge trapping gate configuration, and a control gate configuration connected to the charge trapping gate configuration and controlling access to the charge trapping gate configuration.
[0009] With the objects of the invention in view, there is also provided a semiconductor memory device, including charge trapping gate memory cells for nonvolatile storage of information including at least one of information units and binary bits, each of the memory cells having a charge trapping gate configuration having charge trapping gates each substantially independently storing the information and, as a result, storing a corresponding plurality of one of the information units and binary bits independently of one another in the memory cells, a source/drain configuration accessing the charge trapping gate configuration, and a control gate configuration controlling access to the charge trapping gate configuration.
[0010] The invention's charge trapping memory cell or charge trapping gate memory cell for nonvolatile information storage is characterized in that the charge trapping gate configuration has a plurality of charge trapping gates, in that each of the charge trapping gates is configured for substantially independent information storage, and in that, as a result, a corresponding plurality of information units, in particular, binary bits, can be stored independently of one another in the memory cell.
[0011] Thus, in contrast to the prior art, the invention departs from the 1-bit concept and, consequently, the charge trapping gate memory cell according to the invention is configured for storing a plurality of information units, in particular, binary bits or the like. The configuration is realized by virtue of the fact that, in contrast to the charge trapping gate memory cell according to the prior art, the charge trapping gate configuration is configured with a plurality of charge trapping gates. In such a case, each of the charge trapping gates is configured for separate and independent information storage independently of the other charge trapping gates. By way of example, in each case two bits can be written and retrieved, in accordance with an impressed potential state, in each of the charge trapping regions or charge trapping gates.
[0012] To that end, each charge trapping gate can also be configured for locally taking up or assuming more than two charge and/or potential states, thereby further increasing the information density per charge trapping memory cell, e.g., by virtue of the fact that more than two bits can be stored per charge trapping region or gate.
[0013] The structure of the charge trapping gate memory cell according to the invention is configured particularly flexibly if, in accordance with another feature of the invention, the control gate configuration has a plurality of control gates, a respective control gate is assigned to a respective charge trapping gate and the information states contained therein, and the access to the assigned charge trapping gate is controllable by each control gate. The initially organizational assignment of a respective control gate of the control gate configuration with a respective charge trapping gate of the charge trapping gate configuration results in particularly flexible control of the access to the information to be stored in the charge trapping gate. The initially organizational and sequence-technical assignment between charge trapping gate and control gate will advantageously also be represented in a structural or spatial assignment, in particular, in a particular spatial proximity of the assigned charge trapping gates and control gates with respect to one another.
[0014] A further simplification of the charge trapping gate memory cell according to the invention results if the source/drain configuration has two source/drain regions, the source/drain regions are provided jointly for the plurality of charge trapping gates and/or for the plurality of control gates, and, as a result, all the charge trapping gates are accessible through the two common source/drain regions.
[0015] With regard to a particularly simple fabrication procedure and also with regard to a corresponding functional reliability, the charge trapping gates are configured substantially identically with regard to their geometrical and/or material properties.
[0016] For the reliability of the charge trapping gate memory cell according to the invention, on the other hand, the charge trapping gates are disposed and configured in a manner substantially electrically insulated from one another, from the control gates, and from the source/drain regions. In particular, each charge trapping gate in the charge trapping gate memory cell can be assigned and disposed in a substantially capacitively coupled manner. This is expedient, e.g., when the charge trapping region is formed by electrically conductive islands embedded in an electrically insulating matrix.
[0017] Furthermore, it is advantageous that the control gates are configured substantially identically with regard to their geometrical and/or material properties.
[0018] It is further preferred that the control gates are disposed and configured in a manner substantially electrically insulated from one another, from the charge trapping gates and from the source/drain regions.
[0019] In accordance with another embodiment of the charge trapping gate memory cell according to the invention, the control gates are composed of a polysilicon material, polycide, metal, and/or the like.
[0020] In a further embodiment of the charge trapping gate memory cell according to the invention, the charge trapping gates or charge trapping regions are substantially composed of a material in which charge trapping states can be formed. The material is preferably intended to have or to form a sufficient density of defects that can be occupied by electrons and/or holes. The charge trapping region is, in particular, an insulator, e.g., made of silicon nitride.
[0021] It is provided, in particular, that the charge trapping gates have, form or are formed from an ONO structure, NO structure, or the like, that is to say, from a sequence of nitride/oxide/nitride or nitride/oxide. In such a case, the nitride is present as the actual charge trapping layer. The oxide serves to insulate the actual charge trapping layer, e.g., the nitride, from the control gate and/or from the channel region. An insulation layer above and/or below the actual charge trapping layer produces an additional potential barrier with respect to the control gate or the channel region. Al 2 O 3 , Ta 2 O 5 , HfO 2 , and/or the like can also serve as the charge trapping region.
[0022] To realize the assignment between the charge trapping gates and the control gates, in accordance with a further feature of the invention, the mutually assigned charge trapping gates and control gates are in each case configured in direct spatial proximity to one another, and that, in particular, respective intermediate insulation regions are provided in such a case, if appropriate, in particular, in each case an intermediate dielectric between the respectively assigned charge trapping gates and the control gate.
[0023] In particular, in an edge region or a periphery of a memory cell configuration with a plurality of cells, it is preferred that each charge trapping gate has a first end region and/or a second end region. In such a case, the respective first end region is configured and disposed in direct spatial proximity to the first source/drain region and the respective second end region is configured and disposed in direct spatial proximity to the second source/drain region. As a result, in particular, a spatial or areal overlap is formed between the charge trapping gates, in particular, the respective end regions thereof, and the source/drain regions. Outside the edge regions, that is to say, in the interior of the memory cell configuration, the charge trapping layer is formed in each case continuously, that is to say, with no end regions.
[0024] In accordance with an added feature of the invention, an insulation region, in particular, in the form of a silicon dioxide material, is provided between the respective charge trapping gate, in particular, the end regions thereof, and the source/drain regions.
[0025] In accordance with an additional feature of the invention, a main region of the charge trapping gate cell is formed, to be precise as an elevated region, in particular, as a lamella, a web, a burr, or the like, of a semiconductor material region.
[0026] In such a case, the main region, in particular, the lamella, advantageously has side regions. Furthermore, in such a case the, in particular, two, charge trapping gates are provided in the region of the side regions, in particular, in a manner lying opposite one another with the main region in between, in particular, in direct spatial proximity thereto with provision in each case of an insulation region toward the main region.
[0027] The provision of such a lamellar region with side regions results practically automatically in an electrical insulation and spatial separation between the charge trapping gates to be formed, on one hand, and between the control gates to be formed, on the other hand.
[0028] In accordance with yet another feature of the invention, the source/drain regions are configured as—in particular, n + -doped or p + -doped —regions of the main region isolated, in particular, by a channel region as part of the main region. Although n-channel transistors are preferred, p-channel transistors are, nevertheless, possible and provided. In such a case, source/drain regions are, then, configured to be p + -doped.
[0029] Such a procedure with the configuration as lamella, thus, additionally automatically enables the formation of source/drain regions that are spatially separate from one another and substantially electrically insulated from one another.
[0030] Furthermore, by virtue of its linear extent and by virtue of the possibility of disposing a plurality of such lamellae parallel to one another, the lamellar structure enables a particularly simple procedure when configuring a semiconductor memory device with a plurality or multiplicity of charge trapping gate memory cells according to the invention.
[0031] Thus, in the case of the invention's semiconductor memory device having a plurality of memory cells for nonvolatile information storage, the memory cells are configured as charge trapping gate memory cells according to the invention.
[0032] In accordance with yet a further feature of the invention, adjacent memory cells use at least some of the control gates as common control gates.
[0033] In accordance with yet an added feature of the invention, the plurality of memory cells is configured in a matrix-like manner and on a plurality of substantially identical main regions, in particular, in the form of lamellae, webs, burrs, or the like.
[0034] The design and structure of the semiconductor memory device according to the invention is configured particularly advantageously if the main regions are configured and disposed in a manner extending linearly and substantially equidistantly with respect to one another.
[0035] In such a case, the main regions, in particular, the lamellae, are provided substantially as columns and/or as rows of the matrix-like configuration of memory cells.
[0036] The invention's method for fabricating a charge trapping gate memory cell for nonvolatile information storage is presented below. A fabrication method of the generic type is used as a basis in such a case. In the case of the method of the generic type, a charge trapping gate configuration, a source/drain configuration and a control gate configuration are provided. The charge trapping gate configuration is configured for the actual information storage. The source/drain configuration is configured for access to the charge trapping gate configuration. The control gate configuration is configured for controlling the access to the charge trapping gate configuration and to the information contained therein.
[0037] With the objects of the invention in view, there is also provided a method for fabricating a charge trapping memory cell for nonvolatile storage of information, including the steps of providing a charge trapping gate configuration for storing information including at least one of information units and binary bits, the charge trapping gate configuration having charge trapping gates each storing the information substantially independently of one another in the memory cell and, as a result, storing the information independently of one another in the memory cell, accessing the charge trapping gate configuration with a source/drain configuration, and controlling the access to the charge trapping gate configuration with a control gate configuration.
[0038] The invention's method for fabricating a charge trapping gate memory cell is characterized by configuring the charge trapping gate configuration with a plurality of charge trapping gates, in that each of the charge trapping gates is configured for substantially independent information storage, and in that, as a result, a corresponding plurality of information units, in particular, binary bits or the like, can be stored independently of one another in the memory cell.
[0039] In a particularly preferred embodiment of the fabrication method according to the invention, the control gate configuration is provided having a plurality of control gates, a respective control gate is assigned to a respective charge trapping gate, and the access to the assigned charge trapping gate is configured to be controllable by each control gate.
[0040] On the other hand, the source/drain configuration is provided having two source/drain regions, the source/drain regions are provided jointly for the plurality of charge trapping gates and/or for the plurality of control gates, and, as a result, all the charge trapping gates are accessible through the two common source/drain regions.
[0041] In accordance with yet an additional mode of the invention, in each case the charge trapping gates and/or in each case the control gates are configured substantially identically with regard to their geometrical and/or material properties.
[0042] It is furthermore preferred that the charge trapping gates and/or the control gates are disposed and configured in a manner substantially electrically insulated from one another, from the control gates, and/or from the charge trapping gates and from the source/drain regions.
[0043] In the case of the charge trapping gates, in particular, when using conductive islands in an insulator, it is preferred that they are configured and disposed in a substantially capacitively coupled manner in the charge trapping gate memory cell by virtue of these measures.
[0044] In particular, the charge trapping gates are substantially formed from a material in which the charge trapping states can be formed.
[0045] In particular, a region made of silicon nitride is provided as the charge trapping region. The use of an ONO or NO structure or the like is, preferably, provided in such a case.
[0046] The control gates are preferably formed from a polysilicon material, a polycide, a metal, and/or the like.
[0047] It is advantageous to construct the control gate in each case with low impedance. By contrast, the charge trapping gates are configured with high impedance, in particular, as an insulator.
[0048] To realize the assignment between the respective charge trapping gates and the respective control gates, the mutually assigned charge trapping gates and control gates are in each case formed in direct spatial proximity to one another, and, in such a case, in particular, an additional intermediate insulation region, in particular, an intermediate dielectric, is in each case provided, if appropriate.
[0049] In particular, in the edge region of a configuration of a plurality of cells, each charge trapping gate is configured with a first end region and with a second end region. The respective first end region is configured or disposed in direct spatial proximity to the first source/drain region and the respective second end region is configured or disposed in direct spatial proximity to the second source/drain region. As a result, in particular, a spatial or areal overlap is formed between the charge trapping gates, in particular, the respective end regions thereof, and the source/drain regions. Preferably, an insulation region, in particular, in the form of a silicon dioxide material, is, furthermore, formed between the respective charge trapping gates, in particular, the end regions thereof, and the respective source/drain region.
[0050] It is particularly preferred that in each case an elevated region, in particular, a lamella, a web, a burr, or the like, of a semiconductor material region is provided as a main region of the charge trapping cell. In such a case, the main region, in particular, the lamella or the like, is formed with side regions. Furthermore, charge trapping gates—in particular, two—are provided in the region of the side regions, in particular, in a manner lying opposite one another with the main region in between, in particular, in direct spatial proximity thereto with provision in each case of an insulation region toward the main region.
[0051] It is particularly advantageous that the source/drain regions are configured as—in particular, n + -doped or p + -doped regions of the main region, isolated, in particular, by a channel region as part of the main region.
[0052] The previous characterizing features of the fabrication method according to the invention represent, in part, the structural features of the charge trapping gate memory cell to be formed according to the invention. However, different configurations are additionally conceivable during the fabrication.
[0053] In accordance with again another mode of the invention, first, a semiconductor substrate region, in particular, in the form of p-doped silicon, is provided. Local doping regions, in particular, in n + -doped form, are, then, formed for the source/drain regions to be formed, in particular, by implantation. Afterward, the main region for the memory cell is formed by etching back the surroundings in the semiconductor material region, in particular, using a masking process or the like.
[0054] It is also possible to use n-doped silicon, in which case p + -doped source/drain regions are to be provided.
[0055] The last two steps mentioned can also be carried out with their order reversed so that, first, the main regions, that is to say, in particular, the lamellar structure, is formed by etching back the surroundings in the semiconductor material region, in particular, using a masking process or the like, and, then, doping regions in local form are subsequently formed, in particular, by implantation.
[0056] Advantageously, the local doping regions are formed in a first strip form, and the etching back is effected in a second strip form, transversely with respect to the first strip form.
[0057] Particularly advantageous structures result if, in accordance with again a further mode of the invention, the main region is configured to be linear and/or approximately parallelepipedal. This can be effected by skillful process control during etching back.
[0058] An insulation layer is, then, formed or deposited substantially conformally, in particular, made of a silicon dioxide material and/or, in particular, for the insulation region between the main region and the charge trapping gates to be formed.
[0059] It is furthermore provided as an alternative that the insulation layer is formed by being grown.
[0060] Afterward, a material region is formed, in particular, deposited, for the charge trapping gates to be formed. In such a case, in particular, an ONO structure, NO structure, or the like is used, i.e., a sequence of oxide/nitride/oxide or nitride/oxide.
[0061] In an advantageous manner, the material for the charge trapping gates can remain substantially unpatterned. However, it is also possible for the charge trapping gates subsequently to be patterned, in particular, by etching columns into the material region for the charge trapping gates. In such a case, the columns are formed to run perpendicular to the direction of extent of the main region, that is to say, for example, of the lamella. This is followed by removal or etching back of the material region for the charge trapping gates to a point below the level of a surface region of the main region, for example, of the lamella so that the material region or the material for the charge trapping gates remains only in the region of the side regions of the main region.
[0062] Afterward, a material region may optionally be formed or deposited substantially over the whole area and/or conformally, in particular, for an intermediate insulation region that is optionally to be formed between assigned charge trapping gates and control gates.
[0063] Afterward, a material region is formed or deposited substantially over the whole area and/or conformally, in particular, for the control gates to be formed.
[0064] Afterward, the control gates are patterned—in particular, in the edge region of a memory matrix—in particular, by etching columns running substantially perpendicular to the extent of the main region, and by subsequent removal or etching back of the material region for the control gates to a point below the level of the surface region of the material region for the charge trapping gates and/or, if appropriate, to a point below the level of the surface region of the material region for the intermediate insulation region so that the material region for the control gates remains only in the region of the side regions of the main region, in particular, the material regions for the charge trapping gates and/or, if appropriate, for the intermediate insulation region not being removed.
[0065] Preferably, the structure so obtained is embedded in an insulation region and subsequently formed with a contact connection to the source/drain regions and/or the control gates.
[0066] The above-described and further aspects of the present invention are also explained based upon the remarks in the following text.
[0067] In flash memory cells, it is possible to store a plurality of bits per cell by storing different charge states or by storing a respective bit at spatially separate locations. The last-mentioned possibility necessitates the use of a so-called charge trapping device. This means, for example, that the charge is stored in a nitride layer. What is disadvantageous in such a case, in particular, is that the storage capacity per cell remains limited to two bits.
[0068] The present invention presents a different approach, in which a charge trapping gate memory cell can be realized for storing more than two bits in one cell.
[0069] The storage of two bits in one flash cell has been realized, heretofore, either by the use of an Si 3 N 4 layer (NROM concept). Floating gate cells have, heretofore, used exclusively the storage of a plurality of charge states in a floating gate for storing a plurality of bits in one cell.
[0070] By fabricating Si lamellae as cell main regions, it is possible to realize a charge trapping gate cell that has two or more charge trapping gates but is supplied through the same source and drain regions. As a result, one or even a plurality of bits can be stored in each of the two charge trapping gates. Consequently, it is possible to realize a charge trapping memory cell that has four overlap regions between source and drain pn junction and NO or ONO but is supplied through the same source and drain regions. As a result, one bit can be stored in each overlap region of source/drain and NO or ONO. Overall, it is, thus, possible to store four bits spatially separately from one another.
[0071] A core idea is that the channel of the transistor is shifted from the Si surface to the surface of an Si lamella. This makes it possible to form, at two locations of the lamella, a respective charge trapping gate and, thus, at least one double cell with at least four overlap regions, that is to say, four bits, and, thus, to store four or more bits in the cell.
[0072] The function of the memory cell is explained in the following text.
[0073] If the component, that is to say, the charge trapping gate memory cell, is processed in the manner described below, then, an inversion channel can be produced at the left-hand and right-hand sides of the component both with the first control gate and with the second control gate. Each of these channels can be utilized as a separate memory cell area with two bits in each case, because the gate voltage can be set separately for each side of the component during programming and erasure. During programming, the methods are possible by hot electrons. For erasure, a band-to-band tunneling current generates hot electrons. The programming by hot electrons can be carried out either jointly for each pair of bits assigned to a source/drain region or separately for each bit.
[0074] It is a significant innovation in the case of such a component that although two gate regions are available for storage and driving, they are supplied only by in each case a common source/drain region.
[0075] The following scheme can be used, e.g., during programming, erasing, reading:
Function SD1 SD2 C1 C2 Programming Bit1 GND VPD VPG GND Reading Bit1 VRD GND VRG GND Erasing Bit2 float VED VEG/GND GND Programming Bit2 VPD GND VPG GND Reading Bit2 GND VRD VRG GND Erasing Bit2 VED float VEG/GND GND Programming Bit3 GND VPD GND VPG Reading Bit3 VRD GND GND VRG Erasing Bit3 float VED GND VEG/GND Programming Bit4 VPD GND GND VPG Reading Bit4 GND VRD GND VRG Erasing Bit4 VED float GND VEG/GND
[0076] The fabrication of a memory cell according to the invention is described below. The incorporation of a memory cell into an array is possible in a plurality of architectures (common ground NOR, virtual ground NOR etc.). The latter differ in each case by the extent to which one of the source/drain regions is additionally utilized by further cells and, therefore, if appropriate, need not be separately contact-connected. The incorporation into different array architectures is effected analogously to conventional flash cells. Equally, the contact connection of the control gates is not described below. Such a contact connection is effected, in principle, at the array edge, and both control gates can be contacted-connected on one side, or the control gates can be contact-connected on respectively opposite sides of the array.
[0077] Other features that are considered as characteristic for the invention are set forth in the appended claims.
[0078] Although the invention is illustrated and described herein as embodied in a charge trapping memory cell, method for fabricating it and semiconductor memory device, it is, nevertheless, not intended to be limited to the details shown because various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
[0079] The construction and method of operation of the invention, however, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0080] [0080]FIG. 1A is a cross-sectional side view of an intermediate state reached in the fabrication method according to the invention along the sectional plane A-A of FIG. 1C;
[0081] [0081]FIG. 1B is a cross-sectional side view of an intermediate state reached in the fabrication method according to the invention along the sectional plane B-B of FIG. 1C;
[0082] [0082]FIG. 1C is a cross-sectional plan view of an intermediate state reached in the fabrication method according to the invention along the sectional plane C-C of FIGS. 1A and 1B;
[0083] [0083]FIG. 2A is a cross-sectional side view of an intermediate state reached in the fabrication method according to the invention along the sectional plane A-A of FIG. 2C;
[0084] [0084]FIG. 2B is a cross-sectional side view of an intermediate state reached in the fabrication method according to the invention along the sectional plane B-B of FIG. 2C;
[0085] [0085]FIG. 2C is a cross-sectional plan view of an intermediate state reached in the fabrication method according to the invention along the sectional plane C-C of FIGS. 2A and 2B;
[0086] [0086]FIG. 3A is a cross-sectional side view of an intermediate state reached in the fabrication method according to the invention along the sectional plane A-A of FIG. 3C;
[0087] [0087]FIG. 3B is a cross-sectional side view of an intermediate state reached in the fabrication method according to the invention along the sectional plane B-B of FIG. 3C;
[0088] [0088]FIG. 3C is a cross-sectional plan view of an intermediate state reached in the fabrication method according to the invention along the sectional plane C-C of FIGS. 3A and 3B;
[0089] [0089]FIG. 4A is a cross-sectional side view of an intermediate state reached in the fabrication method according to the invention along the sectional plane A-A of FIG. 4C;
[0090] [0090]FIG. 4B is a cross-sectional side view of an intermediate state reached in the fabrication method according to the invention along the sectional plane B-B of FIG. 4C;
[0091] [0091]FIG. 4C is a cross-sectional plan view of an intermediate state reached in the fabrication method according to the invention along the sectional plane C-C of FIGS. 4A and 4B;
[0092] [0092]FIG. 5A is a cross-sectional side view of an intermediate state reached in the fabrication method according to the invention along the sectional plane A-A of FIG. 5C;
[0093] [0093]FIG. 5B is a cross-sectional side view of an intermediate state reached in the fabrication method according to the invention along the sectional plane B-B of FIG. 5C;
[0094] [0094]FIG. 5C is a cross-sectional plan view of an intermediate state reached in the fabrication method according to the invention along the sectional plane C-C of FIGS. 5A and 5B;
[0095] [0095]FIG. 6A is a cross-sectional side view of an intermediate state reached in the fabrication method according to the invention along the sectional plane A-A of FIG. 6C;
[0096] [0096]FIG. 6B is a cross-sectional side view of an intermediate state reached in the fabrication method according to the invention along the sectional plane B-B of FIG. 6C;
[0097] [0097]FIG. 6C is a cross-sectional plan view of an intermediate state reached in the fabrication method according to the invention along the sectional plane C-C of FIGS. 6A and 6B;
[0098] [0098]FIG. 7A is a cross-sectional side view of an intermediate state reached in the fabrication method according to the invention along the sectional plane A-A of FIG. 7C;
[0099] [0099]FIG. 7B is a cross-sectional side view of an intermediate state reached in the fabrication method according to the invention along the sectional plane B-B of FIG. 7C;
[0100] [0100]FIG. 7C is a cross-sectional plan view of an intermediate state reached in the fabrication method according to the invention along the sectional plane C-C of FIGS. 7A and 7B;
[0101] [0101]FIG. 8A is a cross-sectional side view of an intermediate state reached in the fabrication method according to the invention along the sectional plane A-A of FIG. 8C;
[0102] [0102]FIG. 8B is a cross-sectional side view of an intermediate state reached in the fabrication method according to the invention along the sectional plane B-B of FIG. 8C;
[0103] [0103]FIG. 8C is a cross-sectional plan view of an intermediate state reached in the fabrication method according to the invention along the sectional plane C-C of FIGS. 8A and 8B;
[0104] [0104]FIG. 9A is a cross-sectional side view of an intermediate state reached in the fabrication method according to the invention along the sectional plane A-A of FIG. 9C;
[0105] [0105]FIG. 9B is a cross-sectional side view of an intermediate state reached in the fabrication method according to the invention along the sectional plane B-B of FIG. 9C;
[0106] [0106]FIG. 9C is a cross-sectional plan view of an intermediate state reached in the fabrication method according to the invention along the sectional plane C-C of FIGS. 9A and 9B;
[0107] [0107]FIG. 10A is a cross-sectional side view of an intermediate state reached in the fabrication method according to the invention along the sectional plane A-A of FIG. 10C illustrating a first embodiment of the contact connection process;
[0108] [0108]FIG. 10B is a cross-sectional side view of an intermediate state reached in the fabrication method according to the invention along the sectional plane B-B of FIG. 10C illustrating the first embodiment of the contact connection process;
[0109] [0109]FIG. 10C is a cross-sectional plan view of an intermediate state reached in the fabrication method according to the invention along the sectional plane C-C of FIGS. 10A and 10B illustrating the first embodiment of the contact connection process;
[0110] [0110]FIG. 11A is a cross-sectional side view of an intermediate state reached in the fabrication method according to the invention along the sectional plane A-A of FIG. 11C illustrating a second embodiment of the contact connection process;
[0111] [0111]FIG. 11B is a cross-sectional side view of an intermediate state reached in the fabrication method according to the invention along the sectional plane B-B of FIG. 11C illustrating the second embodiment of the contact connection process;
[0112] [0112]FIG. 11C is a cross-sectional plan view of an intermediate state reached in the fabrication method according to the invention along the sectional plane C-C of FIGS. 11A and 11B illustrating the second embodiment of the contact connection process;
[0113] [0113]FIG. 12A is a cross-sectional side view of an alternative embodiment of the contact connection process according to the invention along the sectional plane A-A of FIG. 12C illustrating the second embodiment of the contact connection process;
[0114] [0114]FIG. 12B is a cross-sectional side view of the alternative embodiment of the contact connection process according to the invention along the sectional plane B-B of FIG. 12C illustrating the second embodiment of the contact connection process; and
[0115] [0115]FIG. 12C is a cross-sectional plan view of the alternative embodiment of the contact connection process according to the invention along the sectional plane C-C of FIGS. 12A and 12B illustrating the second embodiment of the contact connection process.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0116] In the figures of the drawings, unless stated otherwise, identical reference symbols denote identical parts.
[0117] Referring now to the figures of the drawings in detail and first, particularly to FIGS. 1A to 1 C thereof, there is shown, in lateral cross-sectional view and in plan view, a first intermediate state of an embodiment of the fabrication method according to the invention. A semiconductor substrate region 20 with a substantially planar surface 20 a is provided. The semiconductor substrate region or material region 20 may be a p-doped (or n-doped) silicon material or the like. The latter may already be processed and provided, e.g., with suitable wells. Mask regions 100 , which serve to form corresponding doping regions 21 (see, i.e., FIGS. 2A to 2 C), are applied in strip form by implantation in the arrow direction.
[0118] In the transition to the intermediate state shown in FIGS. 2A to 2 C, a doping region 21 is formed locally in the surface region 20 a of the semiconductor material region 20 and to a certain depth underneath, for example, in the form of an n + -doped (or p + -doped) silicon material region, by a corresponding implantation technique. The doping regions 21 formed have a substantially planar surface 21 a . FIG. 2C shows a plan view of the locally doped semiconductor material 20 , and FIGS. 2A and 2B show corresponding cross-sectional side views along the sectional planes A-A and B-B, respectively. The formation of the doping regions 21 results in the creation, by implantation, of a precursor of the source/drain regions SD 1 and SD 2 (see, i.e., FIGS. 3A to 3 C) to be formed for each of the charge trapping gate memory cells 10 (see, i.e., FIG. 8C).
[0119] Afterward, the semiconductor material 20 with the corresponding doping regions 21 is patterned, thereby producing corresponding silicon lamellae L as main regions L for the charge trapping gate memory cells 10 to be formed. As emerges from the plan view of FIG. 3C and the sectional side views of 3 A and 3 B, the lamella L has, as main region L, a substantially linearly extended parallelepiped structure with side regions Lb and a surface region La, which is configured to be substantially planar. By the etching process, in the transition to the intermediate state shown in FIGS. 3A to 3 C, the surface region 20 a of the semiconductor substrate region 20 is etched back to a surface region 20 a ′, thereby uncovering the corresponding structure of the lamella L.
[0120] In principle, in the context of such an etching step, it is possible to form a multiplicity of lamellae that are spaced apart parallel and equidistantly in the manner of a bar grating on the surface region 20 a or 20 a ′ of the semiconductor substrate region 20 , for example, in the context of a fabrication method for simultaneously producing a multiplicity of charge trapping gate memory cells of a semiconductor memory device.
[0121] As emerges from FIG. 3B, the semiconductor material region or semiconductor substrate region 20 is etched back to form the main regions or lamellae L by a depth that approximately corresponds to the depth of the doping or implantation in the doping regions 21 . If appropriate, an overetching may also take place to better separate the doped regions from one another.
[0122] The remaining regions SD 1 , SD 2 of the doping regions 21 serve as source/drain regions SD 1 , SD 2 of the source/drain configuration SD. In between lies the region 22 , the channel region K.
[0123] In the transition to the state of FIGS. 4A to 4 C, an insulation layer 31 is then formed over the whole area and/or conformally, for example, by growth or deposition. In such a case, at the side regions Lb of the lamellae L, insulation regions 30 are produced as part of the insulation layer 31 , which substantially extend vertically there and serve for insulating the charge trapping gates to be formed from the channel region 22 and from the doping regions 21 .
[0124] The insulation layer 31 can be formed strictly conformally or else, as revealed in the comparison of FIGS. 4A to 4 C, be formed with a larger layer thickness D in the region of the doping regions 21 compared with the otherwise thinner layer thickness d. The larger layer thickness D results quite automatically in the case of thermal oxidation and in the case of high dopings, for example, in the case of n + -type silicon, and has the advantage that a lower capacitance is, thus, present between control gate G 1 , G 2 and respective source/drain region SD 1 or SD 2 .
[0125] A material layer 40 for the charge trapping gates C 1 , C 2 (see, i.e., FIGS. 7A to 7 C) of the charge trapping gate configuration C that are to be formed is applied in a manner directly adjoining the insulation layer 30 and 31 , in particular, by deposition. The material layer 40 is a so-called charge trapping layer. In such a case, an NO structure 40 was used in the intermediate state of the fabrication method according to the invention as shown in FIGS. 5A to 5 C. The deposition or formation of such a charge trapping layer for the charge trapping gates C 1 , C 2 is effected over the whole area. The actual charge trapping gates C 1 , C 2 of the charge trapping gate configuration C are formed by the regions E 11 , . . . , E 22 (see, i.e., FIGS. 8A to 8 C) or overlap regions of the material region 40 with the source/drain regions SD 1 , SD 2 .
[0126] In the illustrated embodiment of the fabrication method according to the invention, the material region 40 is not explicitly patterned into the charge trapping gates C 1 , C 2 .
[0127] Additional insulation toward the control gates G 1 , G 2 (see, i.e., FIGS. 7A to 7 C) to be formed that would go beyond the oxide of an ONO or NO structure is also not provided.
[0128] Specifically, the deposition of a material region 60 for the control gates G 1 and G 2 to be formed then takes place directly afterward. The intermediate state shown in FIGS. 6A to 6 C is a whole-area polysilicon deposition. If appropriate, a deposition of polycide, metal, and/or the like is conceivable.
[0129] In the transition to the intermediate state shown in FIGS. 7A to 7 C, the control gates G 1 and G 2 are, then, patterned. The patterning is done by whole-area anisotropic etching back so that the material 60 for the control gates G 1 and G 2 remains only at the edge of the lamella L adjacent to the charge trapping gates C 1 and C 2 . A significant overetching is provided in the embodiment illustrated. This is not necessary, however, with the use of source/drain contacts.
[0130] In the edge region, a masked etching is additionally necessary to isolate the control gates G 1 , G 2 . These processes are not explicitly illustrated here.
[0131] In the transition to the intermediate state shown in FIGS. 8A to 8 C, embedding in an insulation region 70 , for example, in the form of a silicon dioxide, is, then, effected.
[0132] The above-described patterning has, thus, produced a charge trapping gate memory cell 10 in which a charge trapping gate region C has two charge trapping gates C 1 and C 2 that are spatially separate from one another, in which a control gate region G has control gates G 1 and G 2 that are spatially separate from one another and face the respective charge trapping gates C 1 and C 2 , and in which the source/drain region SD has common first and second source/drain regions SD 1 , SD 2 for both gate structures.
[0133] As a rule, such a procedure does not produce a single charge trapping gate memory cell 10 locally, but rather, in a spatially extended semiconductor substrate region 20 , a multiplicity of charge trapping memory cells or charge trapping gate memory cells 10 disposed in matrix form for forming a semiconductor memory device according to the invention for nonvolatile information storage.
[0134] In principle, two different process implementations are conceivable for the respective contact connection of the source/drain regions SD 1 and SD 2 .
[0135] To obtain a cell area that is as small as possible, a lithographic definition of contact holes is dispensed with. The removal of the insulation layers 70 , 31 above the source/drain regions SD 1 and SD 2 is effected either by chemical mechanical polishing or CMP with a stop on the surfaces of the source/drain regions or by etching. Such a procedure is illustrated in FIGS. 9A to 10 C.
[0136] As is shown in the state of FIGS. 9A to 9 C, strip-like free etching is effected by a mask configuration for the bit lines or source/drain line devices.
[0137] In the transition to the intermediate state shown in FIGS. 10A to 10 C, a whole-area metal deposition is, then, effected for the purpose of contact connection, the recesses 92 in the regions 70 , 40 , 30 , 31 to the source/drain regions SD 1 , SD 2 being filled with a corresponding metal 95 . Electrical insulations of these fillings 95 are, then, isolated from one another by etching back or polishing with a stop on the surface 70 a of the embedding insulation region 70 .
[0138] In a different contact connection process, to obtain a large process window and to avoid major overetching, if appropriate, of the charge trapping gates C 1 and C 2 and of the control gates G 1 and G 2 , a contact connection to the source/drain regions SD 1 and SD 2 is provided. Such a procedure is illustrated in FIGS. 11A to 12 B.
[0139] [0139]FIGS. 11A to 11 C thereof first illustrate the formation of contact holes with a corresponding metallic filling 94 of the contact holes. A significant overetching, if appropriate, of the charge trapping gates C 1 and C 2 or of the control gates G 1 and G 2 is not necessary in such a case. In the transition to the intermediate state shown in FIGS. 12A to 12 C, a metal deposition 95 is, then, once again, carried out to form bit lines and source lines. The metal layer can be patterned jointly with the contacts using a dual damascene technique.
[0140] With the use of contactless architecture, metal interconnects can be completely dispensed with. Exclusively the buried bit lines and source lines are, then, used.
[0141] In the last-mentioned case, the lamella is not etched out to a depth such that the doping regions/diffusion regions for the source/drain regions would, thereby, be electrically isolated.
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For particularly flexible and space-saving information storage, a charge trapping memory cell and a corresponding semiconductor memory device include a charge trapping gate configuration provided with a plurality of charge trapping gates each configured for substantially independent information storage. As a result, a plurality of information units can be stored independently of one another in the memory cell. Also provided is a method for producing such a memory cell.
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CROSS REFERENCES TO RELATED APPLICATIONS
This application is a continuation of application Ser. No. 08/959,931 filed on Oct. 29, 1997, now U.S. Pat. No. 5,927,904.
TECHNICAL FIELD
This invention relates to a pumpskid useful in conjunction with a remotely operated vehicle for installing and removing suction anchors in deep water installations.
BACKGROUND AND SUMMARY OF THE INVENTION
U.S. Pat. No. 4,318,641 granted to Hogervorst on Mar. 9, 1982, and assigned to Shell Oil Company discloses a suction anchor. Briefly, a suction anchor comprises a length of steel tubing having a relatively large diameter and a relatively long length, for example, a typical suction anchor might be 12 feet in diameter and 60 feet in length. The suction anchor has an open bottom and a top equipped with structure which allows water to be pumped out of the interior of the suction anchor thereby establishing a pressure differential which causes the suction anchor to penetrate the seafloor. The suction anchor is adapted for subsequent removal from the seafloor by pumping water into the interior thereof.
The Hogervorst '641 Patent discloses in FIGS. 1 and 2 a first pumping apparatus and in FIG. 7 a second apparatus which may be used to effect the flow of water out of or into a suction anchor. Although mentioning structure for clamping the pumping apparatus to the suction anchor, the details of the clamping apparatus are not further disclosed. It is not at all clear from the specification of the Hogervorst '641 Patent that the pumping apparatus described therein can be actuated to effect rapid reversal of the direction of water flow relative to the suction anchor which may be necessary to free the suction anchor from the seafloor in the event that the material into which the suction anchor has been installed has become consolidated around the interior and exterior walls thereof. Also, the apparatus disclosed in FIG. 7 of the Hogervorst '641 Patent for guiding the pumping apparatus downwardly from the surface and into engagement with the suction anchor is not considered adequate for use in deep water installations.
The present invention comprises a pumpskid useful in conjunction with a remotely operated vehicle for installing suction anchors in deep water installations. In accordance with the broader aspects of the invention, the pumpskid is provided with structure for securely clamping the pumpskid in engagement with the suction port of the suction anchor. The pumpskid is provided with remotely operable valving apparatus for causing a pump mounted on the pumpskid to pump water either out of or into the suction anchor as may be required. The valving apparatus may be operated to rapidly reverse the direction of water flow relative to the anchor thereby dislodging a suction anchor which may have become too firmly imbedded in the seafloor.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view of a suction anchor;
FIG. 2 is a front view of the suction anchor of FIG. 1;
FIG. 3 is a top view of the suction anchor of FIG. 1;
FIG. 4 is an enlargement of a portion of FIG. 1;
FIG. 5 is a sectional view of the apparatus shown in FIG. 4 taken along the lines 5--5 therein;
FIG. 6 is a top view of a pumpskid incorporating the present invention;
FIG. 7 is a side view of the pumpskid of FIG. 6;
FIG. 8 is an end view of the pumpskid in FIG. 6 in which certain parts have been broken away and more clearly to illustrate certain features of the invention;
FIG. 9 is a view similar to FIG. 8 showing a different operational condition of the pumpskid of the present invention;
FIG. 10 is a diagrammatic illustration of the utilization of the pumpskid of the present invention; and
FIG. 11 is an enlarged partial side view of the apparatus shown in FIG. 10.
DETAILED DESCRIPTION
Referring to FIGS. 1 through 5, therein is shown a steel suction anchor 70 useful in the practice of the invention. The suction anchor 70 is a right circular cylinder 12 feet in diameter and 60 feet in length, having a wall thickness of 1.5 inches. Skids 71, which may comprise lengths of angled iron or lengths of pipe cut in half longitudinally, are welded to the cylinder comprising the anchor 70 to prevent it from rolling on the deck of an installation vessel.
The suction anchor 70 is open on the lower end 72 and closed at the upper end 74 by a plate 76. A padeye 78, for receiving a mooring line, is attached on an exterior side of suction anchor 70 approximately 40 feet from the top. The top closure plate 76 on the upper end 74 of suction anchor 70 includes ports 82 which allow water to flow through the closure plate 76 as the anchor 70 heaves up and down during lowering to and retrieval from the seafloor. The ports 82 are opened and closed by worm gear actuators 83 which are in turn operated by a manipulator extending from a remote operation vehicle (ROV) 300 which is located relative to the suction anchor 70 by docking posts 84. ROV 300 may comprise a Raycal SEA LION Mk.II heavy work class ROV having 100 horsepower; however any of the various commercially available ROV's having 75 h.p. or more can be used in the practice of the invention.
Vertical alignment of the anchor 70 is determined using a camera on the ROV 300 which observes a bullseye level 85. The ROV 300 also adjusts the horizontal alignment of the suction anchor 70 by checking the suction anchor's heading with a gyrocompass onboard the ROV. If the horizontal alignment is out of tolerance, the ROV 300 rotates the suction anchor 70 by activating thrusters on the ROV. The placement of the ROV 300 on the outer edge of the closure plate 76 ensures that the ROV's thrusters can apply adequate torque to rotate the suction anchor 70 about its axis.
Padeyes 86 are used to connect the anchor to a recovery bridle. An alternate padeye 87 may be used with a single recovery pendant or with double recovery sling. A suction port 88 having a clamp down hub is engaged by the ROV 300 to effect pumping of water into or out of the anchor 70.
A pumpskid 160 comprising the present invention is shown in FIGS. 6, 7, 8, and 9. The ROV 300 is fitted with the pumpskid 160 which is mounted beneath the ROV. The pumpskid 160 includes a centrifugal pump 162, a hydraulic motor 163 which drives the pump 162, pump manifold valve actuators 164 and 165, and latching actuators 166, all powered and controlled by the hydraulic system of the ROV 300. The pumpskid further includes a male connector 168 for the suction port 88. The male connector is provided with O-ring seals 169 to ensure a water-tight connection with the suction port 80. Valves 170 and 172 are operated by actuator 164 and valves 174 and 176 are operated by actuator 165.
As is shown in FIGS. 8, 9, and 10, the ROV 300 docks and latches onto the suction anchor 70 and its suction port 88 by engagement of the male connector 168 and by actuating the latching actuators 166. The latching actuators 166 comprise hydraulic cylinders which are actuated from the ROV 300. Each latching actuator 166 has a piston rod 178 extending therefrom. The distal end of each piston rod 178 comprises a truncated cone 180. The suction port 88 of the suction anchor 70 has a clamp down ring 182 which is provided with a tapered circumferential slot 184 adapted for mating engagement with the cones 180 to securely clamp the pumpskid 160 and the ROV 300 in engagement with the suction anchor 70.
After the latching actuators have been operated to engage the cones 180 with the tapered slot 184 to secure the pumpskid 160 to the anchor 70, the ROV closes the ports 82. The pump 162 of the pumpskid 160 is started and pumps water out of the interior of the suction anchor 70, reducing the water pressure inside relative to the outside pressure. This is accomplished by means of actuator 164 which opens valve 170 and closes valve 172 and actuator 165 which opens valve 174 and closes valve 176, thereby causing water to flow through suction port 88, valve 174, pump 162, and valve 170, and then out through a port 188 which is open to the surrounding sea. As will be understood, the mechanical linkage 190 extending between the actuator 164, the valve 170, and the valve 172 assures that whenever valve 170 is open valve 172 is closed, and vice versa. Likewise, the linkage 192 between actuator 162, valve 174, and valve 176 assures that whenever valve 174 is open valve 176 is closed and vice versa.
The differential pressure under the action of pump 162 acts as a downward force on the top of the suction anchor 70 pushing the suction anchor further into the seafloor to the desired penetration depth. When the desired penetration has been reached, as determined from a depth monitoring system on the ROV 300, the ROV disconnects from the top of the suction anchor 70. This is accomplished by operation of the latching actuators to withdraw the cones 180 from the tapered slot 184. Next the ROV checks the suction anchor penetration by reading the penetration marks at the mudline. When the suction anchor 70 penetration is found to be within tolerance, the ROV 300 closes the suction port 88 so that all openings in the top of the suction anchor are closed. The ROV 300 then disconnects the lowering line from the recovery buoy 146 and is retrieved to the surface.
Whenever removal of the suction anchor 70 is desired, the ROV 300 docks onto the suction anchor top and latches onto the suction port 88. This is accomplished by operating latching actuators 166 to force the cones 180 into the tapered slot 184. As is shown in FIG. 11, the ROV 300 pumps water into the interior of the suction anchor by means of the pump 162. This is accomplished by operating the actuators 164 and 165 to open valve 176, open valve 172, close valve 174, and close valve 170, thereby causing water to flow through port 188, valve 172, pump 162, valve 176 and port 88 into anchor 70.
Due to the pump 162, the water pressure inside becomes greater than the outside water pressure, and the differential pressure results in an upwards force on the suction anchor top. The upwards force, and the pull on the recovery line pulls the suction anchor out of the seafloor. If too much pump pressure is required to pull the suction anchor 70 out of the seafloor, due to too much consolidation of th soil around and inside the suction anchor, the water flow direction from the pump 162 can be reversed instantaneously by changing the positions of valve actuators 164 and 165. By rapidly changing the water flow direction from pumping in to pumping out, the suction anchor 70 will be alternately pulled out and pushed in. When this is done for some time, the soil in contact with the suction anchor cylinder will liquefy, making it easier to pump and pull the suction anchor out off the soil. Suction anchor 70 is raised to the surface by a recovery line and is loaded on an installation vessel using the rise line 50.
The pumpskid 160 is provided with a differential pressure gauge 194 which is connected to the male connector 168 by a pressure line 196. The pressure line 194 indicates the difference in the pressure of the water within the connector 168 with respect to the pressure of the water outside of the suction anchor. The ROV 300 monitors the gauge 194 during suction anchor installation and removal operations to assure that the differential pressure between the inside and the outside of the suction anchor remains within predetermined limits.
The water pumping rate can be adjusted from the ROV 300 by controlling the rate of flow of pressurized hydraulic fluid to the hydraulic motor 163. Reduction in the water flow rate may be required if either the suction anchor penetration rate, or the suction anchor withdrawal rate, or the differential pressure between the interior and the exterior of the suction anchor is too high.
The pumpskid 160 is fitted with syntactic foam buoyancy elements 196 designed for the maximum operating water depth. The buoyancy elements 196 ensure that the pumpskid 160 is slightly buoyant when submerged.
Although preferred and alternative embodiments of the invention 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 and substitutions of parts and elements without departing from the spirit of the invention.
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A pumpskid comprises a frame adapted for connection to a remotely operated vehicle for positioning thereby. A male connector mounted on the frame is adapted for engagement with the suction port on a suction anchor. Clamping apparatus is provided for securing the male connector in engagement with the suction port of the suction anchor and thereby clamping the pumpskid in engagement with the suction anchor. A pump mounted on the frame is connected in fluid communication with the male connector by piping sections which include a port open to the surrounding sea. Valves and valve actuators are provided for causing the pump to cause water flow out of or into the suction anchor, as required.
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This application is a continuation of U.S. patent application Ser. No. 09/546,195, filed Apr. 10, 2000, now U.S. Pat. No. 6,386,243, which is hereby incorporated by reference herein in its entirety. This application claims the benefit of U.S. Provisional Patent Application No. 60/129,094, filed Apr. 13, 1999, which is hereby incorporated by reference herein in its entirety.
BACKGROUND OF THE INVENTION
The present invention relates to winding coils for lamination stacks of a stator. More particularly, the solutions of the invention are concerned with winding coils of alternator stators, and forming the relative end leads. The coils that become wound by the solutions of the invention have an undulated shape, like those that are formed by the apparatus and functioning principles described in U.S. Pat. No. 4,512,376 (herein referred to as “Barrera '376”) assigned to the same assignee of this application. (Barrera '376 is hereby incorporated by reference herein in its entirety.)
As shown in FIG. 1, which is a perspective view of a traditional undulated coil 10 formed according to the principles of Barrera '376, coil 10 has a central axis O, which is substantially perpendicular to the various wire turns 20 of the coil, each of the wire turns defining a plane P. (Those skilled in the art will appreciate that a reference to a “plane” in connection with a helical coil is an approximation used for convenience herein.) Initial lead 11 of the coil is contained in lowermost plane A of the planes P, while final lead 12 is contained in uppermost plane B of the planes P. Coil 10 becomes inserted in respective slots 13 of stator stack 14 as shown in FIG. 2 . This is done by means of an insertion operation requiring pushing of the coil in the longitudinal direction 15 , parallel to axis O with the stator stack in an overhead position, aligned with axis O. The coil is placed on an insertion tool (not shown) to accomplish such an operation. In pushing the coil into the stator stack, radial arms 16 of the coil become inserted in the slots 13 , while bridging sections 17 form the end portions of the coils, and are located outside the extreme faces of the stack. As shown in FIG. 2, leads 11 and 12 have been rotated to become practically parallel to axis O. In FIG. 2 the stator stack has been turned upside down with respect to the position which it would have when pushing in direction 15 of FIG. 1 during the insertion operation. The distances of leads 11 and 12 from axis O after the coil has been inserted in the stator stack are particularly pertinent to presentation of this invention. As shown in FIG. 2, initial lead 11 is nearer to axis O than final lead 12 .
Usually, at least three coils (often referred to as phase coils) like coil 10 are inserted in the stator stack to form the final product. These can be inserted into the stator stack simultaneously or separately. Each coil will be inserted in respective and different sets of slots. When inserted, the coils will be at different radial distances from center axis O of the stack, as shown by references R 1 , R 2 and R 3 in FIG. 3, corresponding to coils 8 , 9 , and 10 . FIG. 3 is a partial view of the stator, as seen from direction 3 — 3 of FIG. 2, but with all three coils inserted, as would be required in the final product. For sake of clarity only one coil has been shown in FIG. 2 .
It is clear from FIG. 3 that initial lead 11 of coil 10 (the nearest to axis O) can be very near to central opening 10 ′ of the stack. This is also evident from FIG. 3 a , which is a view from direction 3 a — 3 a of FIG. 3 . (The location of axis O is not shown accurately in FIG. 3 a or FIG. 11 to avoid unduly enlarging these FIGS.) Furthermore, initial lead 11 does not have bridge portions 17 between itself and central opening 10 ′. This renders initial lead 11 more unstable to lateral displacements (in particular, in the radial direction with respect to the central axis) compared to the other leads. Because of this, small accidental displacements of initial lead 11 toward center axis O can cause it to enter central opening 10 ′ of the stator stack. Such a situation can cause a physical interference of the initial lead 11 with the rotor that is destined to rotate in central opening 10 ′. A frequent consequence of this is damage to the initial lead.
In view of the foregoing, it would be desirable to provide improved methods and apparatus for winding undulated coils for dynamo-electric machine stators. It would also be desirable to provide methods and apparatus for winding undulated coils for dynamo-electric machine stators that reduce the likelihood of damage to lead wires. It would further be desirable to provide an undulated coil whose wire leads are less susceptible to damage.
SUMMARY OF THE INVENTION
It is an object of this invention to provide improved methods and apparatus for winding undulated coils for dynamo-electric machine stators. It is also an object of this invention to provide methods and apparatus for winding undulated coils for dynamo-electric machine stators that reduce the likelihood of interference between lead wires and rotors of dynamo-electric machines. It is a further object of this invention to provide an undulated coil whose wire leads are less susceptible to damage.
These and other objects are accomplished by providing a wire coil winding head which includes, among other features, a gripper configured to hold an initial lead of the wire; a receiver structure configured to receive the wire extending from the gripper and to form a coil of the wire having successive turns that are substantially disposed in respective planes that are substantially perpendicular to a central longitudinal axis of the coil and laterally spaced from one another along that axis; a forming structure configured to produce undulations in the turns of wire in their respective planes while the turns are on the receiver structure, the undulations giving the turns portions that are substantially radial of the axis; and a gripper positioning structure configured to position the gripper relative to the receiver structure so that the initial and final leads can be placed substantially in the same plane as each other and each lead can also be substantially aligned with a respective portion of the coil that is substantially radially disposed with respect to the longitudinal axis. Accordingly, the invention permits both initial and final leads, as installed in a stator, to be disposed at a safe distance from the rotor destined to rotate within the stator.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a traditional undulated coil showing initial and final leads disposed on opposite faces of the coil
FIG. 2 is a perspective view of the undulated coil of FIG. 1 inserted in a stator stack.
FIG. 3 is a partial perspective view of the stator stack of FIG. 2 loaded with three undulated coils as viewed from the direction 3 — 3 in FIG. 2 .
FIG. 3 a is a partial top plan view of the loaded stator of FIG. 3 as viewed from the direction 3 a — 3 a in FIG. 3 .
FIG. 4 is a top plan view of a winding head for winding an undulated coil according to the principles of the invention.
FIG. 5 is a partial perspective view of a coil wound according to the invention.
FIG. 6 is a partial top plan view of a stator similar to that of FIG. 3 a , but having been loaded with the undulated coil of FIG. 5 .
FIG. 7 is a side elevational view from direction 7 of FIG. 4 showing the forming member of the winding head of FIG. 4 that is provided with an implementation of the invention.
FIG. 8 is an elevational view of the forming member of FIG. 7 from direction 8 — 8 in FIG. 7 .
FIG. 9 is a cross-sectional view taken along the line 9 — 9 in FIG. 7 showing a wire engaged by a gripper and passing through an aperture of the forming member of FIG. 7 .
FIG. 10 is a cross-sectional view similar to FIG. 9 showing the wire, the gripper, and the forming member of FIG. 7 after the winding head of FIG. 4 has begun to rotate.
FIG. 11 is an elevational view along direction 11 — 11 of FIG. 4 showing wire turns disposed on the forming member of FIG. 7 and an adjacent forming member.
FIG. 12 is a simplified elevational view, partly in section, showing portions of an illustrative alternative embodiment of apparatus in accordance with the invention.
FIGS. 13 a and 13 b are simplified sectional views taken along the line 13 — 13 in FIG. 12 showing two different operating conditions of a portion of the FIG. 12 apparatus.
FIG. 14 is a simplified sectional view taken along the line 14 — 14 in FIG. 12 .
FIGS. 15 a and 15 b are simplified sectional views taken along the line 15 — 15 in FIG. 12 showing two different operating conditions of another portion of the FIG. 12 apparatus.
FIG. 16 is a view similar to FIG. 13 a or 13 b , but showing two different operating positions and conditions of a portion of the apparatus.
FIG. 17 is a view similar to FIG. 16 showing a later stage in the operation of the apparatus.
FIG. 18 is another view similar to FIG. 17 showing a still later stage in the operation of the apparatus.
FIG. 19 a is a simplified elevational view showing another illustrative alternative embodiment in accordance with the invention.
FIGS. 19 b-d are views similar to FIG. 19 a showing successive stages in the operation of the FIG. 19 a embodiment.
FIG. 20 a is a simplified elevational view showing still another illustrative alternative embodiment in accordance with the invention.
FIGS. 20 b-e are views similar to FIG. 20 a showing successive stages in the operation of the FIG. 20 a embodiment.
FIGS. 21 a is a simplified elevational view showing yet another illustrative alternative embodiment in accordance with the invention.
FIGS. 21 b-e are views similar to FIG. 21 a showing successive stages in the operation of the FIG. 21 a embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 4 shows an apparatus for forming an undulated wire coil according to the principles of the invention. Wire gripper 43 secures the end of a wire W to forming member 40 ′ of support structure 42 . Support structure 42 is a winding head according to Barrera '376, although modified according to this invention, and carries a plurality of forming members 40 that are arranged in a polygon.
Support structure 42 is rotated around axis O while initial lead 11 is gripped by gripper 43 . Wire W is thus pulled from the source and wound on forming members 40 to accumulate a plurality of polygonal wire turns that, together, form a polygonal coil. During rotation of support structure 42 , wire W is guided toward the winding head by stationary wire feeding guide 41 , which is preferably a nozzle. The end of wire W becomes initial lead 11 of initial wire turn 30 .
A second plurality of forming members 45 is also present on support structure 42 , external to the polygonal wire coil formed on forming members 40 . Forming members 45 can push inwardly on the lateral segments, or sides, of the polygonal wire coil. This pushing action, together with a simultaneous radial movement of the forming members 40 toward central axis O, produces undulations in a coil, for example coil 26 , as shown in FIG. 5 .
After undulations have been formed, initial lead 11 is released from gripper 43 and wire W is severed from the source wire to form final wire lead 12 . Final wire lead 12 extends from final wire turn 32 and is arranged in plane B with initial lead 11 . Then, coil 26 is stripped off forming members 40 to be placed on an insertion tool (not shown) for successive insertion into the stator stack with initial and final leads, 11 and 12 , respectively, substantially equidistant from central axis O as shown in FIG. 6 .
From FIG. 6 it is evident that initial lead 11 is more exterior with respect to opening 10 ′ than its counterpart in the prior art discussed above. Also, lead 11 has bridge portions 17 between itself and opening 10 ′. These conditions make initial lead 11 less vulnerable to displacements that would bring it into or over interior opening 10 ′.
The formation of a coil such as coil 26 will now be explained in greater detail with reference to FIGS. 7-11. FIG. 7 is a view along 7 — 7 of FIG. 4, showing forming member 40 ′ with an implementation of this invention at the initial loading stage. According to the principles of this invention, gripper 43 has been placed at level L 1 of forming member 40 ′. Prior to this invention, a gripper was located at level L 2 , as shown by the dashed line representation of the gripper's contour, referenced 43 ″. Additionally, forming member 40 ′ is provided with initial lead aperture 44 adjacent gripper 43 for receiving initial lead 11 while gripper 43 grips initial lead 11 .
Prior to winding a new coil, gripper 43 and initial lead aperture 44 are aligned with feed device 46 by means of a controlled and predetermined rotation of support structure 42 . After alignment, feed device 46 pulls the end of wire W from the source and feeds it through gripper 43 and into initial lead aperture 44 , as shown in FIG. 7 .
FIG. 8 is a view from directions 8 — 8 of FIG. 7 showing that initial lead aperture 44 passes right through forming member 40 ′. Also evident from FIG. 8 is that initial lead aperture 44 has an open side 44 ′. Gripper 43 has been omitted in FIG. 8 to more clearly show initial lead aperture 44 . However middle axis 43 ′ of gripper 43 has been shown. FIG. 9 shows the initial position of initial wire lead 11 in initial wire lead aperture 44 along the line 9 — 9 of FIG. 7 .
Once the end of wire W has been passed through initial lead aperture 11 and gripped by gripper 43 , support structure 42 is rotated in direction 42 ′. FIG. 10 shows that as rotation of support structure 42 occurs, gripper 43 rotates around axis 43 ′ due to torque from tension in wire W. The rotation of gripper 43 causes initial lead 11 to rotate, or pivot, about axis 43 ′ (see arrow A in FIG. 10 ). Initial lead 11 moves substantially in a plane perpendicular to central axis O, passes laterally through open side 44 ′, and rotates into an orientation tangential to an apex of the polygon form (resistance in the rotation of gripper 43 causes wire W to bend around gripper 43 ). Ultimately, as forming members 45 create undulations in the coil, initial lead 11 is aligned substantially parallel to radial arm 36 (see FIG. 5 ).
The side of forming member 40 ′ on which open side 44 ′ is disposed, and the corresponding side of gripper 43 on which initial lead 11 is gripped, depends on the direction of rotation of support structure 42 . The side which has been shown here is consistent with direction 42 ′ as chosen for the rotation of support structure 42 .
FIG. 11 is a view from direction 11 — 11 of FIG. 4 showing how the turns of the polygon coil dispose themselves. The wire for first turn 30 , starting from initial lead 11 , is deposited on forming member 40 ′ and on immediately adjacent forming member 40 ″. It is seen, with reference also to FIG. 7, that the wire just leaving the nozzle during rotation of support structure 42 is received by curved seats 47 .
Curved seats 47 extend from slanted sides 48 of forming members 40 . As additional turns are deposited, the additional turns are allowed to urge the previously wound turns in a progressive and orderly descent out of curved seats 47 and onto inner end portions 48 ″ of slanted sides 48 . As winding continues, wire turns are urged further downward along slanted side 48 , toward outer end portions 48 ′ until slanted sides 48 support a plurality of wire turns 21 shown in FIG. 11 (inner end portions 48 ″ are radially closer to central axis O than are outer end portions 48 ′).
Wire turns 21 form a helical coil that has turns that are placed on various planes P, including initial turn plane A and final turn plane B. The accumulation of wire turns 21 grows toward plane B as more turns are deposited. At any stage during the winding, last deposited wire turn 32 ′ defines a last deposited turn plane, B′, which is closer to initial turn plane A than is final turn plane B. Initial lead 11 in final turn plane B extends from gripper 43 to initial turn plane A on forming member 40 ″ of FIG. 11, by means of slanted transitional wire portion 11 ′. When coil 26 is removed from support structure 42 , initial wire lead 11 is placed flush against last deposited turn 32 ′. Consequently, planes B and B′ merge with each other and last deposited turn 32 , of FIG. 11 becomes final wire turn 32 of FIG. 6 .
It will be appreciated that curved seats 47 have apices 47 ′ that, taken together, define an apical plane substantially perpendicular to central axis O. Gripper 43 is disposed on one side of the apical plane and slanted sides 48 are disposed on the other side. This configuration permits initial lead 11 to be held adjacent the plane in which final lead 12 is destined to be deposited while turns 21 are accumulated. Initial lead 11 and final lead 12 can therefore be arranged in the same plane in the final coil.
After the helical coil is formed, forming members 45 form undulations as discussed above. Then, gripper 43 releases initial lead 11 so that coil 26 can be stripped off the winding head in order to transfer the coil to an insertion tool. As soon as initial lead 11 has been released, gripper 43 grasps the wire extending from the nozzle to final turn 32 . Then, cutter device 50 of FIG. 7 cuts wire W between feed device 46 and forming members 40 to form final lead 12 .
Cutter device 50 cuts wire W after forming member 40 ′ is aligned with cutter device 50 . More precisely, the side of forming member 40 ′ which is opposite the side on which initial lead 11 is ultimately positioned will be aligned with cutter device 50 . Like initial lead 11 , final lead 12 of coil 26 is contained in plane B. Bridge portion 17 ′ of the coil, between initial lead 11 and final lead 12 is formed by forming member 40 ′ as shown in FIG. 5 .
FIG. 12 shows an alternative illustrative embodiment of a forming structure 140 ′, a gripper 143 , and associated apparatus in accordance with the invention. The apparatus shown in FIG. 12 can take the place of forming structure 40 ′ in FIG. 4, with the remainder of the apparatus shown in FIG. 4 being substantially unaltered if desired. FIG. 12 is an elevational view from the center (FIG. 4) of support structure 42 .
Support member 110 is a portion of or is fixedly mounted on support structure 42 (FIG. 4 ). Support member 110 has a downwardly projecting dovetail key 110 a on its lower surface. Key 110 a extends radially relative to the center O of support structure 42 (FIG. 4 ). Forming structure 140 ′ is mounted for movement along key 110 a via a dovetail keyway 112 in the upper surface of a main body portion 111 of forming structure 140 ′.
The actual coil-forming portion of forming structure 140 ′ is the lower portion of structure 113 as viewed in FIG. 12 . This portion of the structure (which extends up into main body portion 111 ) is supported by main body portion 111 and is selectively rotatable about axis 101 ′ relative to the main body portion. The thus-rotatable elements (sometimes referred to generically or collectively by reference number 113 ) include shaft 118 and clamp structure 120 , both described in more detail below. In addition to being generally rotatable with structure 113 , vertically aligned shaft 118 is mounted for limited rotational motion relative to structure 113 about axis 101 ′ as will be described in greater detail below.
Rotatable structure 113 may have a releasable detent connection (not shown) relative to main body portion 111 (e.g., to releasably hold rotatable structure 113 in the rotational orientation shown in FIG. 12 ). Rotatable structure 113 may also be releasably locked in this orientation (or in an operationally similar orientation 180° from the FIG. 12 orientation) by use of the features shown in FIG. 14 . In particular, FIG. 14 shows that at the vertical location shown in that FIG. the outer surface of rotatable structure 113 includes surfaces 123 ′ that are inclined relative to axis 103 ′. Locking block 123 is mounted in main body ill for movement (e.g., by a hydraulic or pneumatic actuator which is not shown) along axis 103 ′ toward ( 123 ″) or away from ( 123 ″′) rotatable structure 113 . When rotatable structure 113 has the orientation (or approximate orientation) shown in FIG. 14 and locking block 123 is reciprocated toward axis 101 ′, inclined surfaces 126 on locking block 123 engage with surfaces 123 ′ on rotatable structure 113 and prevent rotation of structure 113 relative to main body 111 . (Such reciprocation of locking block 123 also has another effect on the apparatus which will be described below.) When locking block 123 is retracted to the position shown in FIG. 14, locking block 123 releases structure 113 for rotation about axis 101 ′. Of course, structure 113 may also have the above-mentioned releasable detent association with main body 111 to releasably maintain structure 113 in a particular rotational orientation such as the one shown in FIG. 14 even when locking block 123 is not engaged.
Shaft 118 , which is vertically disposed in rotatable structure 113 substantially concentric with axis 101 ′, has different exterior surface shapes at various locations along its length. As shown in FIGS. 13 a and 13 b , for example, the lower portion of shaft 118 has an elongated cross section. At this level in the apparatus (and also below this level) rotatable structure 113 is shaped to define four downwardly extending fingers 113 a , 113 b , 113 c , and 113 d disposed around shaft 118 . (The pin 119 shown in dotted lines in FIGS. 13 a and 13 b is actually at a higher level in the apparatus as will be discussed in more detail below.) Fingers 113 a-d and the side surfaces of shaft 118 cooperate to define two substantially parallel slots 114 and 115 that are vertically aligned and that extend across the lower portion of rotatable structure 113 on respective opposite sides of axis 101 ′. Below the lower end of shaft 118 slots 114 and 115 continue (as wider slots 114 ′ and 115 ′, respectively (see FIG. 12 )) and open out the bottom of rotatable structure 113 .
Returning to FIGS. 13 a and 13 b , at the level of the lower portion of shaft 118 , it is seen that shaft 118 has an outer peripheral surface portion that has nonuniform spacing from axis 101 ′ in a direction annularly around axis 101 ′. (Axis 101 ′ substantially coincides with a central longitudinal axis of shaft 118 .) At this level, slots 114 and 115 are wide enough when shaft 118 has the orientation shown in FIG. 13 a to easily and relatively loosely receive a lead L (see FIG. 13 b ) of the wire to be wound. After a slot 114 or 115 has received such a lead L, shaft 118 can be rotated about axis 101 ′ relative to structure 113 to the orientation shown in FIG. 13 b to pinch the lead against the adjacent finger, or anvil structure, 113 a or 113 b and thereby securely hold the lead in the gripper portion 143 (FIG. 12) of forming structure 140 ′. Lead L can be released from gripper 143 by rotating shaft 118 back to the position shown in FIG. 13 a . Lead L can be inserted in a slot 114 or 115 by extending the lead wire axially across the slot. Lead L is typically removed from a slot 114 or 115 by moving the lead downwardly via the associated slot 114 ′ or 115 ′ as the associated coil is stripped from forming structure 140 ′ and the other forming structures of the apparatus.
The elements that are used for rotationally positioning shaft 118 relative to rotatable structure 113 are perhaps best seen in FIGS. 14, 15 a , and 15 b , with the aid of FIG. 12 . FIG. 14 has already been partly described, but it will now be further described with particular reference to pin 119 and related elements. Pin 119 extends transversely across shaft 118 and is fixedly mounted therein. At the level of pin 119 , rotatable structure 113 has windows 122 which allow the ends of the pin to pass out through structure 113 without contacting structure 113 even when shaft 118 is rotated relative to structure 113 . The “normal” position of pin 119 is the one shown in dotted lines in FIG. 14 . This corresponds to the position of pin 119 shown in FIG. 13 b and also in FIG. 15 a.
When locking block 123 is reciprocated toward axis 101 ′ as described earlier in connection with FIG. 14, surfaces 124 on locking block 123 contact the ends of pin 119 and rotate the pin about axis 101 ′ from the dotted line position shown in FIG. 14 to the full line position shown in that FIG. This occurs while surfaces 126 and 123 ′ are cooperating to prevent rotation of structure 113 . Accordingly, rotation of pin 119 causes shaft 118 to rotate about axis 101 ′ relative to structure 113 .
At the level of the apparatus indicated by line 15 — 15 in FIG. 12 and accordingly shown in FIGS. 15 a and 15 b , shaft 118 has a square cross section. Blocks 127 of resilient material surround shaft 118 and are clamped between shaft 118 and upper portions of rotatable structure 113 by clamp structure 120 . The relatively relaxed condition of blocks 127 is the condition shown in FIG. 15 a . When shaft 118 is rotated to the position shown in FIG. 15 b , blocks 127 are elastically deformed and exert torque on shaft 118 which resiliently urges the shaft to return to the position shown in FIG. 15 a . Once again, the condition shown in FIG. 15 b corresponds to the solid line position of pin 119 in FIG. 14 and the position of pin 119 in FIG. 13 a . This is the condition in which locking block 123 in FIG. 14 has rotated pin 119 and therefore shaft 118 relative to structure 113 . This is also the condition (shown in FIG. 13 a ) in which slots 114 and 115 are relatively open and therefore able to receive or release wire lead L. When locking block 123 is retracted from contact with pin 119 (as shown in FIG. 14 ), blocks 127 are able to rotate shaft 118 (relative to structure 113 ) back to the condition shown in FIG. 15 a . This corresponds to the dotted line pin 119 position shown in FIG. 14 and the condition shown in FIG. 13 b . In this condition of the apparatus, blocks 127 resiliently urge shaft 118 to rotate relative to structure 113 to produce the clamping of lead L shown in FIG. 13 b . This clamping can be released by again reciprocating locking block 123 (FIG. 14) toward axis 101 ′ and thereby rotating pin 119 back to the full line position shown in FIG. 14 (corresponding to the condition shown in FIGS. 13 a and 15 b ).
In connection with FIG. 12 it should be noted that the lead-clamping region of the apparatus is preferably deep enough to clamp several wire leads L if desired. Four leads L are shown in FIG. 12 by way of illustration.
FIG. 16 shows additional aspects of the operation of forming structure 140 ′. When forming structure 140 ′ is in the “A” location relative to wire feeding guide 41 , slot 115 is aligned with wire emanating from guide 41 . Slot 115 is also open to receive wire. Accordingly, wire can be axially extended from guide 41 (e.g., by elements such as 46 in FIG. 7) to enter slot 115 as shown on the left in FIG. 16 . Forming structure 140 ′ can then be operated (as described in the immediately preceding paragraphs) to clamp wire lead L in slot 115 . Support structure 42 (FIG. 4) can then be rotated relative to guide 41 to cause forming structure 140 ′ to begin to pull additional wire from guide 41 as shown in FIG. 16 by the movement of forming structure 140 ′ from the “A” position shown on the left to the “B” position shown on the right. Because slot 115 does not pass through rotational axis 101 ′, the use of forming structure. 140 ′ to pull wire from guide 41 causes the resulting tension in the wire to exert a rotational torque (about axis 101 ′) on forming structure 140 ′. Because locking block 123 is in the retracted position shown in FIG. 14 after lead L has been inserted in slot 115 and clamped therein, this tension in the wire causes forming structure to rotate approximately 90° about axis 101 ′ as it moves from the “A” position in FIG. 16 to the “B” position in that FIG. Shaft 118 rotates with the remainder of structure 113 and therefore continues to clamp the wire after forming structure leaves the “A” position shown in FIG. 16 .
After the “B” condition shown in FIG. 16 is reached, support structure 42 (FIG. 4) continues to rotate relative to guide 41 , drawing additional wire from the guide and causing that wire to deposit in a coil on forming structure 140 ′ and the other forming structures 40 as described earlier in this specification (see also FIG. 17, which shows wire W that has been deposited around forming structure 140 ′). The shape of the outer surface of the lower portion of rotatable structure 140 ′ (on which the turns of wire forming this coil are partly deposited) is generally like the shape described earlier for surfaces 47 / 48 (FIG. 8 ), except that in forming structure 140 ′ this shape is “in the round” or a surface of revolution, concentric with axis 101 ′. Forming structure 140 ′ therefore operates on the coil in the manner generally described earlier, and it operates in this manner regardless of its rotational orientation about axis 101 ′.
After the desired number of wire turns have been deposited on forming structures 40 and 140 ′, rotation of support structure 42 is stopped with forming structure 140 ′ again adjacent to wire guide 41 . Forming members 45 are then moved radially inward as shown in FIG. 18 to produce undulations in the coil of wire. Forming structures 40 and 140 ′ may also move radially inward to a lesser extent. The radially inward motion of forming members 45 pulls in on lead L, which is still gripped by forming structure 140 ′. This produces a torque on forming structure 140 ′, which causes it to again rotate about axis 101 ′ by approximately 90° to the position shown in FIG. 18 . Finish lead F is then cut by cutter 50 . The coil is now ready to be stripped off forming members 40 and 140 ′. Accordingly, shaft 118 is rotated to release start lead L and the coil is stripped off the forming members and further processed to place it on a stator as described earlier in this specification. Elements 40 , 45 , and 140 ′ are thereafter returned to their radially outer positions.
It will be noted in FIG. 18 that slot 114 in forming structure 140 ′ is now opposite guide 41 . A new start lead can therefore be fed into slot 114 (e.g., by elements like elements 46 in FIG. 7 ). The rotation of shaft 118 can then be released in order to clamp this new start lead and the above-described coil winding process can begin again. Slots 114 and 115 are thus used alternately in successive coil winding operations.
Because gripper 143 for start lead L is located near the top of the structure on which the turns of wire are formed and gradually moved down, the start and finish leads L and F in FIG. 18 are in approximately the same transverse plane of the finished coil. The apparatus shown in FIGS. 12-18 therefore produces coils having the same characteristics and advantages as are described above for the coils and apparatus shown in FIGS. 4-11.
In some applications of the invention it may be desirable to be able to produce some coils with start and finish leads in the same transverse plane (as described above), and to produce other coils with start and finish leads in respective start and finish planes that are spaced from one another at respective opposite axial ends of the finished coil. If that is desired, the apparatus of this invention can include a second forming structure generally like 40 ′ or 140 ′ but with the gripper for the start lead farther down and therefore able to hold the start lead in a plane different from the plane in which the finish lead will be disposed. When it is desired to produce a coil with co-planar start and finish leads, the coil is started using the forming structure 40 ′ or 140 ′ with the higher start lead gripper 43 or 143 . When it is desired to produce a coil with start and finish leads in axially spaced transverse planes, the coil is started using the forming structure 40 ′ or 140 ′ with the lower start lead gripper 43 or 143 . If forming structures of type 140 ′ are being used, the above-mentioned anti-rotation detent (or, alternatively, engagement of locking block 123 ) prevents rotation of the forming structure that is not currently being used to grip the start lead.
As another example of possible modifications within the scope of this invention, instead of elements 41 and 42 being substantially fixed in the vertical direction during the operations relevant to the invention, elements 41 and 42 can be relatively movable in the vertical direction as shown in the sequence of FIGS. 19 a-d . In these FIGS. the entire wire-receiving and coil-forming structure is indicated generally by the reference number 42 . As shown in FIG. 19 a wire source 41 is initially relatively high relative to structure 42 so that initial lead 11 (or L in embodiments like those shown beginning with FIG. 12) can be gripped by relatively high gripper 43 / 143 . As winding of the coil begins, wire source 41 moves down relative to structure 42 as shown in FIG. 19 b . Thereafter, as winding continues, wire source 41 gradually moves up again relative to structure 42 as shown progressively in FIGS. 19 c and 19 d . Thus the turns of wire W are deposited on structure 42 from the bottom to the top of that structure. The final turn is deposited in approximately the same relatively high plane in which initial lead 11 (or L) is held by gripper 43 / 143 throughout the winding operation. Final lead 12 is severed from wire source 41 by cutter 50 . The coil undulation steps can be performed as described earlier in this specification and are not shown in the FIG. 19 series. Either or both of structures 41 and 42 can be moved to produce the relative vertical and rotational motions shown in FIGS. 19 a-d . This type of embodiment can be used to avoid the need for successive turns of wire to slide down the coil forming surfaces as the turns are formed.
FIGS. 20 a-e show another example of modifications within the scope of this invention. In this embodiment gripper 43 / 143 for initial lead 11 is movable vertically relative to wire-receiving and coil-forming structure 42 . Gripper 43 / 143 is initially relatively low relative to structure 42 and receives and holds the end of wire from wire source 41 as shown in FIG. 20 a . Wire source 41 is shown rotating around structure 42 and also gradually moving up relative to structure 42 as turns of wire are deposited on structure 42 (see FIGS. 20 b , 20 c , and 20 d ). The final turn of wire is severed from source 41 by cutter 50 as shown in FIG. 20 d to produce final lead 12 in a relatively high, final turn plane. Gripper 43 / 143 then moves up relative to structure 42 to place initial lead 11 in approximately the same plane as final lead 12 . The coil undulation steps can be performed as described earlier in this specification and are not shown in the FIG. 20 series. Any of elements 41 , 42 , and 43 / 143 can be moved vertically to produce the relative vertical movements shown in FIGS. 20 a-e . Additionally, any of elements 41 , 42 , and 43 / 143 can be rotated about central axis O to wind wire onto structure 42 .
FIGS. 21 a-e show a modification of the invention in which the final lead is placed in the same plane as the initial lead. Accordingly, gripper 43 / 143 for initial lead 11 is movable vertically relative to wire-receiving and coil-forming structure 42 . Gripper 43 / 143 is initially relatively high relative to structure 42 and receives and holds the end of wire from wire source 41 (FIG. 21 a ). Wire source 41 is rotated around structure 42 and also gradually moves down relative to structure 42 as turns of wire are deposited on structure 42 (FIGS. 21 b-d ). Wire source 41 then moves gradually up relative to structure 42 to place a final turn in approximately the same plane as initial lead 11 (FIG. 21 e ) . The final turn of wire is then severed from source 41 by cutter 50 to produce final lead 12 in a relatively high, final turn plane. The coil undulation steps can then be performed as described earlier in this specification.
Although embodiments in which initial lead 11 and final lead 12 are disposed in a relatively high position relative to structure 42 have been emphasized, it will be appreciated that it also may be desirable to have both initial lead 11 and final lead 12 disposed in a relatively low position with respect to structure 42 . In particular, initial lead 11 and final lead 12 can be disposed in the lowermost plane of the coil relative to structure 42 . This alternative results in a coil that, once installed in a stator in the position of external (outermost) coil 8 of FIG. 6, will have both initial leads disposed at the inner radius of the outer coil. Leads thus disposed, in an external coil, are more insulated from mechanical damage than leads disposed at the outer radius of the outermost coil.
An external coil configured to have both initial and final leads disposed along the inner radius when the coil is installed in a stator can be formed using a winding structure having a gripper 43 at lower level L 2 as shown in FIG. 7 . Accordingly, initial lead 11 is held at level L 2 while wire turns are accumulated on structure 42 . After the desired number of wire turns is deposited on structure 42 , wire guide 41 is moved vertically relative to structure 42 to bring the final turn (destined to terminate in final lead 12 ) into substantially the same plane as initial lead 11 .
Additionally, external coils having both leads disposed at the inner radius can be formed using a winding structure having a forming structure, such as forming structure 140 ′, provided with a gripper 143 disposed in a lower position with respect to forming structure 140 ′ as discussed above. Accordingly, the wire is gripped in the lower position, wire turns are accumulated on structure 42 , and wire guide 41 and structure 42 are moved vertically relative to one another to allow a final lead 12 to be placed in substantially the same plane as initial lead 11 .
Whether using forming member 40 ′ with gripper 43 or using forming member 140 ′ with gripper 143 , the relative vertical displacement of structure 42 with respect to guide 41 may be accomplished by movement of either of elements 42 and 41 or both may be moved in concert.
Alternatively, an innermost coil having both initial and final leads disposed along the outer radius of the installed coil, such as coil 10 of FIG. 6, may be formed by placing both leads 11 and 12 in the lowermost plane of the coil relative to structure 42 . However, such a coil requires the use of an intermediate tool in addition to the insertion tool mentioned above if the coil is to be installed with the leads positioned in the radially outer position such as in coil 10 of FIG. 6
The principles of the invention can be applied to forming undulated semi-phase coils like those described in European application No. 97110542.4 and in forming uninterrupted semi-phase coils like those described in U.S. Pat. No. 5,881,778, both of which are hereby incorporated by reference herein in their entireties.
One skilled in the art will appreciate that the present invention can be practiced by other than the described embodiments, which are presented for the purpose of illustration and not of limitation.
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Apparatus and methods for reducing the likelihood of damage to wire leads of undulated coils for dynamo-electric machine stators are provided. The invention provides a rotating winding head equipped with a coil former that has a wire gripper and an initial wire lead slot. The gripper retains the initial wire lead. The slot permits the initial wire lead to be fed to the gripper from a stationary wire source. The gripper maintains the initial wire lead in a predetermined plane of the coil and can secure the initial wire lead in the plane in which the final lead wire will eventually be disposed. The gripper also rotates the initial wire lead into radial alignment with a lobe of the undulated coil. Once installed in a stator, the initial and final wire leads can both be disposed along the outer radius of the coil and are thus protected from interference with a rotor that is destined to rotate within the stator.
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This application is a Division of application Ser. No. 08/174,280, filed Dec. 28, 1993.
BACKGROUND OF THE INVENTION
The present invention relates to current collecting equipment and a method of current collecting for a railway vehicle, such as a high speed railway vehicle.
Aerodynamic noise which is produced by a high speed railway vehicle rapidly increases with increasing speed of the vehicle proportional to approximately the eighth power of its velocity. On the other hand, the concern about preservation of the environment has been growing and will be an important factor in the future. Therefore, it is required for a vehicle running at a high speed (for example, over 270 km/hr) to carry low noise current collecting equipment.
A low noise current collecting equipment is proposed in an article entitled "Speeding up SHINKANSEN" (Nikkei mechanical, published on May 4, 1992, pages 22 to 40). The following is described in this report (especially on page 27).
It is desirable for lowering noise that a member having a contact strip as a current collecting member has a streamlined shape. Taking the combination of the streamline-shaped member and strut supporting the member into consideration, a lifting force takes place. The lift causes the contact strip to become detached from the trolley wire or contacts to the trolley wire with exceeding force to cut the trolley wire. With the provision of two kinds of current collecting equipment depending on the direction of running of the vehicle, switching from the one kind to the other kind is performed at a turn back station. The current collecting equipment is T-shaped and is formed with large sized members in order to decrease any produced frequency vibration.
Further, taking these facts described above into consideration, a view of a T-shaped current collecting equipment is illustrated in FIG. 5 in the paper. This current collecting equipment comprises a member supporting a contact strip with a fine motion spring, a cylinder for raising and lowering the member through a restoring spring, and an insulator supporting the cylinder.
On the other hand, the conventional pantograph type current collecting equipment comprises a pantograph having a contact strip, a pneumatic cylinder for raising and lowering the pantograph, four insulators to support and insulate a support base mounting the pantograph and the pneumatic cylinder, and a conducting cable installed on the roof of the vehicle. The compressed air supply to the pneumatic cylinder is performed with an installed pipe penetrating through the insulator.
Further, other constructions of current collecting equipment for high speed railway vehicles in order to lower noise are also described in Japanese Patent Application Laid-Open No. 5-49103(1993) and Japanese Patent Application Laid-Open No. 5-49104(1993).
The current collecting equipment for high speed railway vehicles, the T-shaped current collecting equipment proposed in the above paper and the current collecting equipment for high speed railway vehicles proposed in the above Japanese Laid-Open Patent Application Applications, are designed to resolve the problems which accompany high speed running. However, since the functions of the pantograph, (1) the function of contacting and following a trolley wire and (2) the function of conducting current to direct collected electric power to the vehicle, are attempted to be provided with only one construction, as in the conventional pantograph, it is difficult to satisfy the seemingly conflicting requirements concerning responsive following of the trolley wire and lowering of noise caused by increasing the vehicle speed.
For example, the conventional T-shaped current collecting equipment has the following disadvantages. First, the cylinder for raising and lowering the contact is positioned on the contact strip side near to the supporting insulator. Therefore, said cylinder for raising and lowering has to be provided as a pneumatic cylinder. Although it is desirable for a high speed vehicle, from the point of view of responsive control, to employ an oil-hydraulic cylinder, the oil-hydraulic cylinder cannot be employed in the equipment.
Further, the raising and lowering cylinder has a control system to maintain the contact pressure against the trolley wire constant and requires means for detecting the contact pressure, such as a load cell, to be used as a control input. The position to set the contact pressure detecting means is on the contact strip side near the raising and lowering cylinder. Since the position is in a portion of the high voltage region, the countermeasure for insulation of the detecting means is required.
Furthermore, although the current collecting equipment is designed for collecting current, the above-mentioned paper does not disclose its current conducting system at all.
With regard to the cylinder that is used to raise or lower the current collecting equipment when it is switched at a turn back station, since the current collecting equipment not being used forms a projection, there is a limit to the lowering of noise produced by the equipment.
It is thought that the current collecting equipment described in the above-mentioned Japanese Laid-Open Patent Applications also have the same problem.
SUMMARY OF THE INVENTION
An object of the present invention is to provide current collecting equipment and a method for current collecting suitable for a high speed railway vehicle which is excellent in its controllability and in responsiveness for trolley wire following.
Another object of the present invention is to provide current collecting equipment and a method for current collecting suitable for a high speed railway vehicle which is low in producing noise.
A further object of the present invention is to provide current collecting equipment and a method for current collecting which is capable of preventing production of noise caused by the current collecting equipment not being used.
A still further object of the present invention is to provide a vehicle having current collecting equipment which is always capable of correctly controlling the contact pressure against the trolley wire during high speed running.
The objects of the present invention can be attained by separating the functions of a pantograph into a function of following the trolley wire and a current conducting function for collected electric power in order to make the current collecting equipment carry out each of the functions. In other words, the object of the present invention can be attained by providing current collecting equipment which comprises a current collecting member, a driving system to move said current collecting member, an insulating element to connect said current collecting member and said driving system, a conductive element juxtaposed with said driving system and having its outer surface covered with an insulator to receive the current collected with said current collecting member and to direct the current to the load side.
The objects of the present invention can also be attained by providing current collecting equipment which comprises a current collecting member, a driving system to move said current collecting member, a conductive element to direct the current collected with said current collecting member, a support base mounting said driving system and said conductive element, rotating means for rotating said support base around a horizontal axis, a containing part mounted on the roof of the vehicle to contain said rotating means and containing said driving system and said current collecting system.
According to the present invention, a part of the structure having a current collecting function can be light in weight and small in size and can improve the control characteristic for the following of the trolley wire, since the part of the structure having the current collecting function, which comprises the current collecting member and the driving system, is installed separately from a part of the structure having the power current conducting function, which can, further, maintain the power current collecting function sufficiently.
Furthermore, the generation of noise during vehicle running can be suppressed since there is provided a containing system on the roof of the vehicle inside of which the driving system is always contained and the part of the structure having the current collecting function together with the part of the structure having the power current conducting function is contained when it is not used
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view showing the external appearance of a high speed vehicle to which the present invention is applied.
FIG. 2 is perspective view of the vehicle in FIG. 1 when the current collecting equipment is in a current collecting condition.
FIG. 3 is a plan view of current collecting equipment and a containing dome forming an embodiment according to the present invention.
FIG. 4 is a vertical sectional view of current collecting equipment and a containing dome according to the present invention.
FIG. 5 is a transverse view taken on the plane of the line I--I in FIG. 4.
FIG. 6 is a vertical sectional view of the main part of the current collecting equipment in FIG. 3.
FIG. 7 is a side view showing the driving system of the current collecting equipment in FIG. 3.
FIG. 8 is a plan view of the current collecting equipment in FIG. 6.
FIG. 9 is a front view of the current collecting equipment in FIG. 6.
FIG. 10 is a sectional view of the current collecting equipment taken on the plane of the line II--II in FIG. 6.
FIG. 11 is a sectional view of the current collecting equipment taken on the plane of the line III--III in FIG. 10.
FIG. 12 is a sectional view of the current collecting equipment taken on the plane of the line IV--IV in FIG. 10.
FIG. 13 is a plan view showing the operation of a shutter system in a containing dome.
FIG. 14 Is a plan view showing the operation of a shutter system in a containing dome.
FIG. 15 is a vertical sectional view showing the main part of a shutter system.
FIG. 16 is a vertical sectional view showing the main part of another shutter system.
FIG. 17 is a enlarged side view of a containing dome.
FIG. 18 is a view for explaining the operation of extending current collecting equipment from a containing dome.
FIG. 19 is a view for explaining the operation of housing current collecting equipment in a containing dome.
FIG. 20 is a perspective view of the external appearance showing the condition of housing current collecting equipment in a containing dome.
FIGS. 21(a) through 21(c) are horizontal sectional views of the supporting insulator and the conductive element, and relationships between air flow and the configuration.
FIG. 22 is a vertical sectional view showing the positional relationship between the current collecting member and the supporting insulator,
FIG. 23 is a schematic circuit diagram showing an example of the electric wiring in a train of vehicles applied to the present invention.
FIG. 24 is a vertical sectional view of the high voltage unit box in FIG. 23.
FIG. 25 is a block diagram showing a structure of the control system in FIG. 23
FIG. 26 is a diagram showing the flow of a control command for the current collecting equipment.
FIG. 27 is a flow diagram showing the operational procedure of a pulling-down command for the current collecting equipment.
FIG. 28 is a flow diagram showing the operational procedure of a raising command for the current collecting equipment.
FIG. 29 is a block diagram showing the structure of an oil-hydraulic driving system for the current collecting equipment.
FIG. 30 is a block diagram showing the structure of a push-up force control system for the current collecting equipment.
FIG. 31 is a block diagram showing the structure of a current collector driving system.
FIG. 32 is a block diagram showing the structure of a containing driving system.
FIG. 33 is a vertical sectional view of current collecting equipment forming another embodiment according to the present invention.
FIG. 34 is a view showing an example of the structure applied by the present invention to a current supplying system of a third rail type.
FIG. 35 is a plan view showing a further embodiment of current collecting equipment and a containing dome according to the present invention.
FIG. 36 is a view showing a cross section taken on the plane of the line V--V in FIG. 35.
FIG. 37 is a view showing a cross section taken on the plane of the line VI--VI in FIG. 35.
FIG. 38 is a view showing the contained condition of the current collecting equipment in FIG. 35.
FIG. 39 is a view showing current collecting equipment with an emergency ground switch.
FIG. 40 is a perspective view showing a current collector in accordance with the present invention.
FIG. 41 is an illustrative view of the air flow around a current collector in accordance with the present invention.
FIG. 42 is an illustrative view of air flow around a conventional stream-lined current collector.
FIG. 43(a) is a diagram of a collector head and FIG. 43(b) is a graph showing the pressure distribution in the lateral direction on the surface of the collector head of current collecting equipment in accordance with the present invention.
FIG. 44(a) is a diagram of a collector head and FIG. 44(b) is a graph showing the pressure distribution in the lateral direction on the surface of the collector head of a conventional stream-lined current collecting equipment.
FIG. 45 is a view showing the shape of a low aerodynamic noise collector head and supporting column in accordance with the present invention.
FIG. 46 is a graph showing the results of a wind tunnel test showing the noise decreasing effect of current collecting equipment in accordance with the present invention.
FIG. 47 is a perspective view showing another current collector in accordance with the present invention.
FIG. 48 is a cross-sectional view showing another current collector in accordance with the present invention.
FIG. 49 is a perspective view showing another current collector in accordance with the present invention.
FIG. 50 is a view showing another current collector in accordance with the present invention.
FIG. 51 is a graph showing the results of a wind tunnel test showing the effect of the present invention
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A first embodiment according to the present invention will be described in detail, referring to FIG. 1 through FIG. 32.
FIG. 1 shows an external appearance of a high speed vehicle to which the present invention is applied. In order to lower noise, the external surface of a vehicle body 2 is formed smooth, and bogies are also covered with covers 2C. The bottom half of a current collector 20 is positioned so as to be surrounded by a containing dome 4. The main parts of current collecting system, such as a supporting insulator for insulation, a cable head for current conduction, a collector head and so on, are projected from the center of the containing dome 4 and into contact with a trolley wire, when current is to be collected. The external surface of the containing dome 4 is streamline-shaped to lower aero-dynamic resistance. Inside of the containing dome, there are a base plate 3, a high voltage cable 5, a high voltage connector 6, and a cylinder 7 coupled to a connecting rod 8 to raise and lower the current collector 20.
For such a vehicle, the voltage in the trolley wire is generally used alternating current of 25 kV, the current is 200 A, and the cycle is 50-60 Hz. In order to maintain a sufficient insulation distance and a creeping distance for such a high voltage, it is necessary to use a very tall current collector 20 and an insulator having a lot of folds. Such an insulator produces a running aerodynamic resistance and becomes a large noise source when the vehicle is running at a high speed. Therefore, the current collector 20 according to the present invention is contained in the inside of the dome 4 when the apparatus is not in a current collecting condition.
FIG. 2 shows a condition where the current collector 20 is in the current collecting condition and extends up near the center of the containing dome 4. The gap between the current collector 20 in the current collecting condition and the containing dome 4, which forms the opening for the current collector, is entirely closed with a shutter system 9.
FIG. 3 through FIG. 7 show detailed views of the current collector 20 and the containing dome 4 in accordance with the present invention.
Since the current collector 20 is not operated with a folding structure, as provided in the conventional pantograph, the current collector 20, as one unit of a collector head 22, a support insulator 30, a driving rod 31 for upward and downward driving, a cylinder 32, a cable head for current conduction 50, is rotated with a rotating system 40 around a horizontal axis so as to be lowered into the containing dome 4 when it is not in the current collecting condition. Therewith, the aero-dynamic resistance and the noise during vehicle running can be decreased.
Raising and lowering of the current collector 20 is performed with a cylinder 7 and a rod 8 to rotate the current collector 20 around an axis 40A of the rotating system 40. Incidentally, the rotating system 40 is supported with a fixed member 41 which is mounted on the base plate 3 on a car body 2.
When the current collector 20 is raised or lowered, the shutter system 9 is opened with operation of a cylinder 42 and a rod 43. When the current collector 20 is collecting current or is contained in the containing dome 4, the shutter system 9 is closed. These operations are carried out by the control of a sequencer or a computer installed separately. The details of this will be described later.
A high voltage flexible cable 44 is subject to heavy fatigue and is required to be changed on schedule since it is moved every time the current collector 20 is raised and lowered. Therefore, a high voltage connector 6 is provided between the flexible cable 44 and the high voltage cable 5 buried in the car body 2 so as to make changing of the high voltage flexible cable 44 easy.
Any water which enters into the containing dome 4 from the gaps between shutters 110, 120, 130, 140 or the gaps between the insulator 30, or the insulating member 50 and the shutter 130, flows out to the roof of the vehicle through drain holes 46 provided on both side walls in the bottom of the containing dome 4. As the roof of the vehicle body 2 is, as shown in FIG. 5, arc-shaped in a convex upward orientation, draining is easily carried out through the drain holes 46 on both side walls of the containing dome 4.
As shown in FIG. 6 through FIG. 9, contact strips 21 for current collecting are buried on the top of the collector head 22 having a delta-wing shape, and are pushed against the trolley wire 1 by contact strip pressing springs 23 and with a driving system which will be described later. The collector head 22 is secured to the top of the supporting insulator 30 with bolts, and the supporting insulator 30 is secured to a driving rod 31 positioned below and projecting from a driving cylinder 32. The numeral 33 designates a load cell to detect the force acting between the driving rod 31 and the supporting insulator 30, that is the reaction force to push up the collector head 22. The driving rod 31 is pushed up by means of hydraulic pressure produced with a hydraulic pressurizer separately installed in such a way that the contact pressure of the current contact strips 21 against the trolley wire 1 is controlled to become optimum.
The collector head 22 has a nearly triangular wing shape when it is seen from above, as shown in FIG. 8. The ends in the width-direction of the collector head 22 are bent in a downward direction. There are contact strips 21a secured on the top surface of the wing in those portions. These contact strips are made of a harder material than the material of the wing (such as, for example, steel, copper, brass). These members are dummy strips to prevent the collector head 22 from abrasion when the trolley wire comes to the wing end portion and the collector head 22 itself contacts the trolley wire 1. The contact strips 21a are secured to the collector head 22 with bolts such that the strips have the same potential as the collector head to prevent sparking. The bolts are positioned in the hollow parts in the contact strips to decrease projecting parts on the surface. There is no spring 23 between the contact strips 21a and the collector head 22.
The contact strips 21 and 21a are electrically connected to a conducting wire 51a. When the collector head 22 is made of a non-conductive material, such as FRP, a conductive member is provided between the contact strips 21 and 21a and the conductive wire 51a.
The external surface of the connecting part of the supporting insulator 30 and the collector head 22 is arc-shaped. Thereby, the production of aerodynamic noise generated in said portion is decreased.
The longitudinal cross section of the collector head 22 is stream-line shaped the height of which is progressively reduced in the rear-ward direction, as shown in FIG. 6. The material of the collector head 22 is aluminum in order to decrease its weight. It may be formed mainly with resin, the surface of which is coated with GFRP or CFRP.
The driving rod 31 for the driving cylinder 32 and the bottom portion of the supporting insulator 30 are connected through a unit of the load cell 33 by way of the top and bottom flanges thereof. The bottom portion of the supporting insulator 30 is cylindrical, and the diameter of the supporting insulator 30 is the same as the diameter of the cylinder portion of the cylinder 32. This portion is covered with a sleeve 59. The sleeve 59 is longitudinally cut into halves which are fixed to the cylindrical portion of the supporting insulator 30 and the cylinder portion of the cylinder 32 from outer-ward of the radial direction using flat countersunk head screws. The length of the sleeve 59 is longer than the stroke of the driving rod 31. The corner of the top end of the sleeve 59 is rounded. The driving rod 31 is a rod driven with oil-hydraulic pressure. The numeral 130 indicates a shutter to cover the surrounding area of the sleeve 59, which will be described later.
The cable head for current conduction 50 described above has a structure in which the conductive element 53 penetrates the center of the insulator 52 in the axial direction. The top of the conductive element 53 projects from the insulating portion, and has a brace projecting sideways which is fixed with bolts. Instead of this, a protective cap may be attached to the portion, as well known. A high voltage flexible cable 44 is attached to the bottom end of the conductive element 53. The outer diameter of the cable head 50 gradually decreases toward its top, and the cable head 50 serves as a high voltage insulator.
The brace on the top of the conductive element 53 and the collector head 22 are connected with a conductive wire 51 which is flexibly braided. The conductive wire 51 is fixed with bolts and nuts and is formed of a braided wire, so that the collector head 22 may easily move upward and downward relative to the cable head 50, and has at least one U-shaped turn in a part thereof. The U-shaped turn in the conductive wire 51 makes upward and downward movement easy even when the distance between the fixed ends of the conductive wire 51 is small. The cable head 50 is positioned at the back of the supporting insulator 30, and the connecting positions of the conductive wire 51 with the collector head 22 and the conductive element 53 are also positioned at the back of the supporting insulator 30.
The insulator in the cable head 50 has, as shown in FIG. 6, an uneven portion in its surface, and its bottom portion 52 is columnar. The bottom of the column 52 is fixed to a base 55 from an upper side with bolts. The base 55 and the cylindrical portion of the cylinder 32 are formed as a single unit structure. As seen in FIG. 10 through FIG. 12, there is an opening (55a) in the side surface of the base 55 (the back side in the direction of running) so that the connection portion of the high voltage flexible cable 44 can be inserted from a side direction into the bottom portion of the insulator 52. There are flanges in the bottom of the cable head 50 and in the top of the base 55 which are connected together with a plurality of bolts.
There are connecting portions for the cylinders 7 for raising and lowering the collector head in both sides of the base 55 on either side of the hollow space in the connecting portion of the cable head 50 through which the high voltage flexible cable 44 is penetrated. The extending direction of the cylinder 7 is in the longitudinal direction of the vehicle. The high voltage flexible cable 44 is positioned between the two cylinders 7, as seen in FIG. 10. The high voltage flexible cable 44 is connected to the cable 5 through the connector 6. The high voltage flexible cable 44 is softer than the cable 5. The connector 6 has such a structure that connecting and disconnecting of the connector 6 and the high voltage flexible cable 44 is comparatively easily carried out.
Now returning to FIG. 6 and FIG. 7, the parts, such as the driving cylinder 32, the connector 6, the cylinder 7 and so on, are mounted on the base plate 3 through the fixed member 41. The base plate 3 is fixed to a base secured to the roof of the vehicle itself with bolts. There is a cut part in the base plate 3 below the high voltage flexible cable 44 to make room for bending of the high voltage flexible cable 44 and to make bending of the high voltage flexible cable during rotation of the supporting insulator 30 easy.
By employing this structure, the operation of the driving rod 31 does not affect the high voltage flexible cable 44. The driving rod 31 has a function to push the current collecting contact strip 21 against the trolley wire 1 with a desired pressure as it moves up and down with considerably high frequency. Although the high voltage flexible cable 44 is bent with the operation of the cylinder 7 for raising and lowering the collector head, the bending condition occurs substantially only at the turn back operation and the frequency of bending is extremely small. Therefore, a long wearing life of the cable can be achieved. The load cell 33 can detect the contact pressure with the trolley wire 1.
Since the supporting insulator 30 is disposed between the driving rod 31 and the collector head 22, the driving rod 31 is not subjected to a high voltage. Therefore, an oil-hydraulic type driving cylinder 32 can be employed, which improves the responsiveness to the control signal.
Similarly, since the load cell 33 (pressure sensor) is also installed in a position where a high voltage is not applied, an accurate control input can be obtained.
Since the sleeve 59 is positioned at the bottom end of the supporting insulator 30 and the gap between the supporting insulator 30 and the containing dome 4 can be made small, the inflow of rain, snow or air into the sleeve 59 can be prevented even though the diameter of the rod 31 at the bottom end of the support insulator is small. Therefore, the length below the bottom end fold of the supporting insulator 30 can be made small.
Incidentally, the sleeve 59 may be eliminated when the length of the column at the bottom end of the supporting insulator 30 is longer than the stroke of the driving rod 31.
As shown in FIG. 13 and FIG. 14, there are shutters 110, 120, 130 and 140 in the portion where the current collector 20 penetrates the dome 4, and the shutters usually close the opening. The shutter 110 is a shutter to close the opening through which the collector head 22 penetrates, and is formed of a piece of flat plate. The shutters 120, 120 are shutters to cover the opening through which the supporting insulator 30 penetrates, and are divided in the width-direction of the vehicle into two portions to close one opening with a pair of flap type shutters. The shutters 130, 130 are sliding type shutters to cover the opening where the insulators 30 and 52 pass in the condition of raising upright, and are divided in the width-direction of the vehicle into two portions to close one opening with a pair of shutters. When the shutters 130, 130 close the opening, two circle holes are opened to be penetrated with the sleeve 59 and the insulators 30 and 52. The shutter 140 is a piece of sliding type shutter to close the same opening that the shutters 140, 140 close when the current collector 20 is contained in the containing dome 4. At this time, the shutters 130, 130 do not close the opening.
Referring to FIG. 14 though FIG. 16, the structure of the driving mechanism of the shutter 110 will be described next. The shutter 110, as shown in FIG. 15, is of a
sliding type, and is slid along the longitudinal direction of the vehicle. There are guide rails 115 supporting both side ends of the shutter 110 in both sides of the opening 110a closed with the shutter 110 in the width-direction of vehicle. Both sides of the shutter 110 are supported with the guide rails 115 through four rollers 112. The guide rails 115 guide the top, bottom and side of the rollers 112. The shutter 110 is positioned on the reverse side of the containing dome 4 when the opening is open, and is fitted in the opening when the opening is closed. In other words, when the opening is closed, the upper surface of the shutter 110 is coextensive with the upper surface of the containing dome 4. The guide rails 115 have curves so as to move the shutter 110 as described above. A cylinder 42 for up- and down-ward driving of the shutter 110 is installed on the base plate 3.
The shutters 120 are, as shown in FIG. 16, opened and closed by turning with hinges 122 as turning axes. Cylinders 129 are installed on the base plate 3.
The shutters 130 are of a sliding type similar to the shutter 110. The guide rails 135 for the shutters 130 are not installed in the side portion of the opening. The reason for this is to prevent crossing over with the shutter 140. Therefore, the portion of the shutter to close the opening has no guide roller either. In order to put guide rollers on the shutter 130, the shutter 130 has such a shape that the shutter is largely extended toward the opposite side of the running direction when the opening is opened. Cylinders 139 are installed on the base plate 3. The other structure for the shutters 130 is the same as the structure for the shutter 110.
In FIG. 15 and FIG. 16, there are provided heaters 47 and 48 in the circumference of the shutters 110 and 120 of the containing dome 4. A heater may be provided at the portion where the shutters 120 contact each other, if necessary. The other shutters 130 and 140 also have heaters (not shown). When the shutters tend to freeze in winter season, the shutters 110, 120, 130 and 140 are opened after the heaters are supplied electric power to melt ice, and so the current collector 20 is easily controlled through its raising and lowering movements.
The shutters 140 are of a sliding type similar to the shutter 110. The guide rails 145 for the shutters 140 are not installed in the side portion of the opening. The reason for this is to prevent crossing over with the shutter 130. Therefore, the portion of the shutter to close the opening has no guide roller either. In order to put guide rollers on the shutter 140, the shutter 140 has such a shape that the shutter is largely extended toward the opposite side of the running direction when the opening is opened. Cylinders 149 are installed on the base plate 3. The other structure for the shutters 140 is the same as the structure for the shutter 110.
The containing dome 4 is, as shown in FIG. 17, partitioned into three parts 4A, 4B, 4C. The containing dome part 4A is the region from the guide rail 135 for the shutter 130 to the guide rail 115 for the shutter 110. The containing dome 4 has inspection hatches 4Aa, 4Bb, 4Cc on the side surface of the containing dome in appropriate positions to be used for inspection, assembling and replacement of parts for the devices in the containing dome 4.
The current collector 20 projecting upward from the containing dome 4 is, as shown in FIG. 18 through FIG. 20, contained in the containing dome 4 by driving the cylinder 7. First, the collector head 22 is slightly pulled down (approximately 100 mm) to be detached from the trolley wire 1, as shown in FIG. 18. Next, as shown in FIG. 19, the shutter 9 is opened, and the current collector 20 is lowered completely into the containing dome 4, and then finally the shutter 9 is closed. The condition where the current collector 20 is contained in the containing dome 4 is as shown in FIG. 15, all the openings being closed with the shutter system 9, the external surface of the containing dome 4 being of a sooth stream-lined shape, which hardly produces running resistance or noise source during high speed running. The following shows an example of the detailed dimensions of an embodiment according to the present invention.
______________________________________height of containing dome HD = 700 mmtotal length of containing dome L = 9300 mm(hereinbefore referred to FIG. 4)width of base of containing dome WDL = 2500 mmwidth of top of containing dome WDH = 1800 mm(hereinbefore referred to FIG. 5)height of supporting insulator for HG = 500 mminsulationheight of cable head for conduction HC = 430 mmheight of front part of collector head TA = 130 mmlength of current collector head LA = 600 mmin the running directiondistance between top of cable head TB = 290 mmfor conduction and trolley wire(hereinbefore referred to FIG. 7)______________________________________
Room sufficient to contain the driving cylinder 32, the connector 6, the cylinder for raising and flatting 7 and so on can be obtained when the movable stroke of the driving cylinder 32 is approximately 300 mm.
The assembling procedure will be described next. The current collector 20, composed of the collector head 22 and the driving cylinder 32, having the supporting insulator 30, the cylinder 7 for raising and lowering the current collector, the high voltage flexible cable 44 and the connector 6, are mounted on the base plate 3. The current collector 20 is in the condition where it is housed in the containing dome 4 (FIG. 14). At this time, the driving rod 31 is withdrawn into the cylinder 7, reducing its length. The top of the collector head 22 is set on a buffer base (not shown in the figure) installed on the base plate 3. Then, the cylinders 42, 129, 139, and 149 are secured to the base plate 3.
The assembled apparatus is mounted on the roof of the vehicle 2 and the base plate 3 is fixed to the roof with bolts. In this condition, the current collector 20 is in the housed condition. In this condition, the cylinders 42, 129, 139, and 149 may be also set in.
Next, the connector 6 and the cable 5 are connected. And, pipes for driving liquid are connected to each of the cylinders 7, 32, 42, 129, 139, and 149. The other work is to connect a signal wire to the sensor.
Then, the containing dome 4A is mounted on and fixed to the roof 2 with bolts. The shutters 110, 120, 130, and 140 have been attached to the containing dome 4A in advance. The cylinders 42, 129, 139, and 149 and the shutters 110, 120, 130, and 140 are connected by access through the inspection hatches.
Next, the end portions of the containing dome 4B and 4C are mounted on the roof and fixed to the roof 2 and the containing dome 4B. The portion connecting the domes to each other is of an over-lapping structure.
The replacement of the high voltage flexible cable 44 or the cable head 50 is carried out in such a manner that the containing dome 4 is removed in the condition where the current collector 20 is contained in the containing dome 4. The replacement work can be comparatively easily carried out, since the opening 55a of the base 55 is directed upward and the connector 6 is provided.
The cylinders 42, 129, and 139 may be horizontally installed in the containing dome 4B. When this is done, the dome 4 may be formed as a unit. Further, the inspection hatches may be miniaturized. The cylinders 42, 129, and 139 may be easily connected with the shutters and the containing dome 4. This assembling is carried out with the containing dome 4 turned upside down.
The shutters 130 in the containing dome 4, where the sleeve 59 penetrates, are also opened upward in an arc-shape. Each of the shutters 130 has two semi-circular openings. And, two holes are formed with closing of the two shutters 130. The sleeve 59 and the insulator 52 penetrate these two holes. The holes have rubber buffers on their peripheries. The hole for the sleeve 59 is slightly larger than the other, since the sleeve 59 moves upward and downward.
FIG. 21(a) through FIG. 21(c) show horizontal sectional views of the supporting insulator 30 (30a, 30b, 30c) and the cable head 50, and relationships between air flow and the configuration.
The FIG. 21(a) shows a combination where the round-shaped support insulator for insulation 30a has a slightly larger diameter than the diameter of the round-shaped cable head for conduction 50 (the aero-dynamic diameters are nearly the same), and they are placed in the stream. Although the air flow mainly hits the support insulator 30 which is placed in front in the running direction, the air stream also hits the cable head 50 to produce noise in some cases.
The FIG. 21(b) shows a combination where the support insulator 30b has a significantly larger diameter d1 than the diameter D1 of the cable head 50. The air flow mainly hits the support insulator 30 which has a large diameter and is placed in front in the running direction, and the air does not hit the cable head 50. This results in a decrease in noise totally.
d.sub.1 >D.sub.1
d 1 and hatched part: concave portion of the insulator 30
D 1 outer diameter: convex portion of the cable head 50 insulator
The FIG. 21(c) shows a combination where the support insulator 30c is formed to have a wide width perpendicular to the air flow and a nearly stream-line shape, so that the cable head 50 is actively hidden within the protected area of the supporting insulator 30. When this is done, the noise decreases more than the case FIG. 21(b). It is desirable that the diameter or width of the supporting insulator 30 is, as described above, larger than the diameter of the cable head 50. Incidentally, the supporting insulator 30 is made of epoxy resin.
The distance L between the two insulators 30 and 52 is determined from the low noise point of view. It is thought that interference of two noises may lower the noise. Although the diameters of the supporting insulator 30 and the cable head insulator 52 are the same size from the top to the bottom (above the containing dome 4), the diameters may be varied, for example, such as to increase in the downward direction. When this is done, it is expected that the noise may be lowered since the air flow varies in the vertical direction.
Further, as shown in FIG. 22, it is desirable that the supporting insulator 30 is placed just below the center of gravity G of the collector head 22, that is the position on which the weight of said collector head 22 acts and the lift force L caused by the air flow hitting said collector head acts. A lift force L acts on said collector head 22 during vehicle running. When the vertical sectional shape of said collector head 22 is symmetric with respect to a horizontal plane, the velocity in the downside thereof is lower than the velocity of the upside thereof since said supporting insulator 30 is installed. Therefore, the lift force acting in said collector head 22 acts upward. When the position of the lift force acting on the collector head 22 is at the position of the center of gravity G and said supporting insulator 30 is installed at that position, the angular moment ML shown in the figure is not caused. This means that no excessive force acts on the supporting insulator 30.
It is desirable that the acting position of the center of gravity G of said collector head 22 agrees with the acting position of the lift force of said collector head 22. In a case where it is hard to cause said position of the center of gravity G to correspond with the acting position of the lift force, it is desirable to make them as close as possible.
It is thought that the containing dome 4 may cause upward turning of the air flow. As a countermeasure against this problem, the collector head 22 may be tilted so as to match the angle of the air flow, or the collector head 22 may be moved to a place where there is no effect of the angle of air flow caused by the containing dome 4. Therein, it is desirable that the angle and the movement of the collector head 22 are adjusted corresponding to the speed of the vehicle.
FIG. 23 shows an application to a train of vehicles of the present invention.
In this figure, the vehicles 2 (2A-2H) are running from the right hand side to the left hand side as shown with an allow. Generally, current collection is carried out with a vehicle in the rear of the train in order to decrease the aero-dynamic resistance and to lower noise by placing the current collector 20 in a place where a boundary layer more readily develops. Therefore, in the figure, the two current collectors (20F, 20H) in the rear are raised, and the two current collectors (20A, 20C) in the front are housed in the containing domes 4.
The electricity collected with the current collector 20 is directed to a high voltage unit box 60 through a high voltage connector 6 and a high voltage cable 5. In this high voltage unit box 60, there are installed a vacuum circuit breaker 61 and a vacuum circuit breaker 62 which are connected with a cable head for current conduction 68 and a high voltage take-out cable 67, respectively. The vacuum circuit breaker 61 prevents the lowered and housed current collector 20, which is out of use, from applying high voltage with other current collectors 20 through the high voltage take-out cable 67.
The vacuum circuit breaker 62 switches on and off current to current collector 20 installed in each vehicle. The current passed through the vacuum circuit breaker 62 in such a way is dropped in voltage with a main transformer 63, then the current is converted with a main convertor 64 into three phase alternating current having its frequency and voltage controlled corresponding to the speed and the traction force of the vehicle to drive a main motor 65. The current, after driving the main motor 65, returns to a rail 69 through a wheel and axle 66. A high voltage switch 61 cuts off high voltage from the current collector 20 at the time when the current collector 20 is housed.
FIG. 24 shows an example of the arrangement of units in the high voltage unit box 60. There are installed two vacuum circuit breakers 61 and 62 and four cable heads 68 in one box 60. Although the inside of the high voltage unit box is at atmospheric pressure, the box is sealed. The vacuum circuit breaker 61 and the vacuum circuit breaker 62 are installed in the top and the bottom of the box 60. Bare wires 68a are used for connections among both of the vacuum circuit breakers 61, 62 and the insulators 68 for take-out conductors 68aa, 68ab, 68ac, 68ad. The vacuum circuit breakers 61 and 62, as known in the art, switch on and off the current in response to magnetic coils 61a and 62a. A cable 68aa is used for connecting to the high voltage flexible cable 44, a cable 68ab being used for connecting to the main transformer 63, cables 68ac and 68ad being used for connecting to the other unit boxes 60. The numeral 68A indicates an arrester which is connected to the vacuum circuit breaker 62. The vacuum circuit breakers 61 and 62 have the same specification. Since the vacuum circuit breaker 61 is installed under the floor of the vehicle, the center of gravity of the vehicle can be lowered as compared to when it is installed on the roof. Further, the two vacuum circuit breakers 61 and 62 are installed in one unit box 60, which also leads to a lowering of cost.
Each vehicle in a train of vehicles has a control unit 84 having the following structure as shown in FIG. 25. Since the train has four current collectors 20 (20A, 20C, 20F, 20H), the control unit 84 controls four sets. A set is composed of one vacuum circuit breaker 61, one driving cylinder 32, two cylinders 7 for raising and lowering the current collector, and six cylinders 42, 129, 139, and 149.
There are two sets of input switches SW, each of which is installed in each of the driving cabs on both end vehicles of the train. The one set of switches SW is composed of a switch 9D1 to instruct which vehicle in the train is the front vehicle, a switch 9D2 to raise all of the current collectors 20, a switch 9D3 to lower and house all of the current collectors 20 into the containing domes. The control unit 84 includes a memory 84A, a CPU 84B, and an input/output interface 84C.
The CPU 84B executes a program stored in the memory 84A, and executes various kinds of processing. When the switch 9D1 for instructing which vehicle in the train is the front vehicle is switched on, the CPU 84B, as shown in FIG. 26, outputs a lowering command (262) to the two current collectors (20A, 20C) in the front side of the train and sends a raising command (264) to the two current collectors (20F, 20H) in the rear side.
The operating procedure according to said lowering command is as shown in FIG. 27. In the condition in FIG. 4, the vacuum circuit breaker 61 is cut off (271) to prevent sparking. Next, the driving rod 31 is lowered up to the lowermost position to realize the condition in FIG. 18 (272). And, the shutters 110, 120, and 130 are opened by using the cylinders 42, 129, and 139 (273). Next, the current collector 20 is housed in the containing dome 4 using the cylinder 7 as shown in FIG. 19 (274). Then, the shutters 110, 120, and 140 are closed by using the cylinders 42, 129, and 149 (275). Therein, since the shutters 120 are overlapped, the operation timings of the cylinders 129 are different from each other.
The current collector 20 is capable of being lowered with a small power, since the current collector 20 is first lowered with the driving rod 31 to be detached from the trolley wire 1. Further, lowering the current collector 20 makes the length of the shutters 120 short and also makes the length of the containing dome 4 short.
In the condition of lowering and housing the current collector 20, since the two openings on the shutter 130 (holes for the sleeve 59 and for the insulator 52) are closed with the shutter 140, it can be expected to lower the noise during running. Further, the inflow of rain or snow can be minimized.
When a rising command for the current collector 20 is given in the step 264 in FIG. 26, as shown in FIG. 28, the shutters 110, 120, and 140 are opened (281), and the current collector 20 is raised (282), and then the shutters 110, 120, and 130 are closed (283). Next, the collector head 22 is raised using the driving rod 31 to contact the trolley wire 1 (284). Finally, the vacuum circuit breaker 61 is switched on (285). The effects are the same as described above.
A link mechanism may be installed between the insulator 30 and the driving cylinder 32 instead of using the driving rod 31 to move the insulator 30 upward and downward directly. When this is done, the driving cylinder 32 may be used also in place of the cylinder 7 for raising and lowering the current collector 20.
FIG. 29 through FIG. 31 show a structure of the collector head driving system 230 for vertical displacement control of the current collector 20. As depicted in FIG. 6, a load cell for control 33 and a displacement meter 34 are inserted between the supporting insulator 30 and the driving rod 31. The outputs from the load cell 33 and the displacement meter 34 are lead to a control unit 83 together with the output information from a speed information detector 85 and a railway information detector 86, and the control unit 83 calculates the optimum contact pressure against the trolley wire 1 and transfers an electric signal to a servo amplifier in a servo control device 240. A servo valve 243 receives the electric signal from the servo amplifier 242 and controls the liquid flow from a oil-hydraulic source 241 with the electric signal to control the pushing-up force u between the driving cylinder 32 and the driving rod 31. The following symbols are used in the description below.
f*: target contact force
fq: lift force
f: contact force
fx: fluctuating force signal
f : contact force estimated signal
fa : disturbance suppressing force estimated signal
P: estimating state value vector
A: matrix constant
L : vector constant
C: vector constant
B: vector constant
r: control signal =k 2 (f*-f )-fa
u: pushing-up force
k 1 ': disturbance compensating gain
k 1 ": contact force gain
k 2 : normal compensating gain
a 1 -a 8 : weight functions (forming k 1 ')
a: equivalent mass of the trolley wire 1
b: equivalent damping coefficient of the trolley wire 1
m 1 : mass of the contact strip 21
m 3 : mass of the collector head 22 and the supporting insulator for insulation 30
y 1 ,y 1 ',y 3 ": vertical displacement, vertical velocity, vertical acceleration of the contact strip 21
y 3 ,y 3 ',y 3 ": vertical displacement, vertical velocity, vertical acceleration of the collector head 22 and the supporting insulator for insulation 30
z,z',z", z'": displacement, velocity, acceleration, acceleration ratio of the irregularities of the trolley wire 1
c 1 : damping coefficient of the spring 23 for pushing the contact strip
k 1 : spring constant of the spring 23 for pushing the contact strip
ζ: ratio of damping coefficient
X: state value vector
W: disturbance vector
D, E: vector constants
H: vector constant
Q: output state value vector from the normal difference compensating unit 232
F: scalar constant
G: vector constant
The servo control device 240 operates the driving cylinder 32 and the driving rod 31 with a control signal r from a control unit 83 to produce a push-up force u to the collector head 22, the support insulator 30 and so on. The control unit 83 is installed on the earth side (electric potential is zero) in the collector head containing dome 4 in the roof of the vehicle 2. The control unit 83 inputs a fluctuating force signal fx and a vertical displacement signal Y3 to a contact force observer unit 233 within the control unit. The signals are obtained through amplifying the output signals from the load cell 33 and the displacement meter 34 which are installed between the support insulator 30 and the driving rod 31, using a detected signal checking circuit 253. Further, the control signal r is fed at the same time to the contact force observer unit 233. Then, the contact force observer unit 233 outputs with estimation a contact force estimated signal f and a disturbance suppressing force estimated signal fa . The contact force observer unit 233 is composed of a state value estimating unit 236, a disturbance suppressing force gain unit 237 and a contact force estimating unit 238.
Furthermore, the control unit 83 has a target value command unit 231, which sets with optimizing and varying a contact pressure target value f* by means of the combination of an information signal on running place and a detected signal on running speed, using the running information (speed information 85, route information 86) from the controller on the vehicle, and a normal difference compensating unit 232, which calculates said control signal r [=k 2 (f*-f ) through obtaining differences between the contact pressure target value f* set by the target value command unit 231 and the contact force estimated signal f output with estimation by the contact force observer unit 233 and the disturbance suppressing force estimated signal fa .
Herein, k 2 is a normal compensating gain in the normal difference compensating unit 232. The load cell 33 is installed between the support insulator 30 and the driving rod 31, and detects the load, either tension or compression, with high accuracy to output a fluctuating force signal fx.
Similarly, the displacement meter 34 is installed between the supporting insulator 30 and the driving cylinder 32, and outputs the vertical displacement, the velocity and acceleration of the driving rod 31. The lift force mainly acts on the collector head 22, the supporting insulator 30 and so on, and consists of the resultant lift force fq of average lift force and fluctuating lift force acting vertically. Therefore, when the vehicle runs at a high speed, the fq acting on the total body of the current collector 20 increases, and accordingly the contact pressure f substantially varies.
Said contact pressure is expressed with an equation (Equation 1).
f=fx-m.sub.1 y.sub.1 "-m.sub.3 y.sub.3 "-fq (Equation 1)
wherein, the y 1 , Y 1 ', Y 1 " are the displacement, velocity and the acceleration of the current collector contact strip 21 and so on. The y 3 , y 3 ', y 3 " are the displacement, the velocity and the acceleration of the collector head 22, the supporting insulator for insulation 30 and so on.
The target value command unit 231 sets with optimizing and varying the contact pressure target value f* by using the running information (running speed, running route, position, weather, running time, earthquake etc.) transferred from a vehicle controller. The normal difference compensating unit 232 receives an input signal which subtracts the contact force estimated signal f from the f* set by the target value command unit 231, and outputs the signal Q [=k 2 (f*-f )] which is obtained through multiplying the compensating gain k 2 and the signal ef. The control signal r, which is obtained by subtracting the disturbance lift pressure estimated signal fa from Q through a subtractor, is input to the servo control device 240. The driving rod 31 is operated using the control signal r so as to suppress the lift force fq and the external force from the trolley wire 1.
In order to calculate the disturbance suppressing force estimated signal fa , the disturbance suppressing force gain unit 237 multiplies the following weight functions of the disturbance compensating gains k 1 ' (a 1 -a 8 ) to the output signals (y 1 , y 3 , y' 1 , y' 3 , z, z', z", z'") from the state value estimating unit 236, which contains the lift force fq and the external force from the trolley wire 1. Wherein, z, z', z", z'" are the displacement, the velocity, the acceleration and the acceleration ratio of the convex and concave of the trolley wire 1.
a 1 =268,500, a 2 =-268,500, a 3 =-28,650, a 4 =-1,212, a 5 =0, a 6 =29,850, a 7 =45, a 8 =0.
Then, fa can be obtained.
fa =k.sub.1 'xP (Equation 2)
The contact force estimating unit 238 calculate s the contact force estimated signal f (the equation (Equation 3)) using the output signals P (y 1 , y 3 , y' 1 ,y' 3 , z, z', z", z'") from the state value estimating unit 236. Wherein, a is an equivalent mass of the trolley wire 1, and b is an equivalent damping factor of the trolley wire 1. ##EQU1##
This equation can be expressed as follows,
f =k.sub.1 "xP (Equation 3)
Therein, k 1 is the spring constant of the pushing spring 23 for the contact strip, c 1 is the damping coefficient of the pushing spring 23 for the contact strip, and k 1 " is the contact force gain.
The signal P described above will be explained next. After judging whether or not the output signals detected with the load cell 33 and the displacement meter 34 are normal, using the detected signal checking circuit 253, the varying signal fx and the vertical displacement y 3 together with said control signal r is input to the state value estimating unit 236, and then the unit 236 outputs the eight state values described above, y 1 , y 3 , y' 1 ,y' 3 , z, z', Z", Z'", through state estimating by means of the minimum dimension observer method. The calculation to obtain the state values using the minimum dimension observer method (Gopinath's method) is described in the book titled "Observer" published from Corona Co. (1988) page parts 21-32. The equations of state (Equation 4) are shown below.
d/dt(P)=(A-L C)xP+BxU+L xF.sub.x (Equation 4)
Wherein, the P is an estimated state value of observer (y 1 , y 3 , y'1 1 , y' 3 , z , z' , z" , z'" ), the F x being an input scalar to the force detector, the A being an 8×8 matrix, the L being a 1×8 vector, the C being a 1×8 vector, the B being a 8×1 vector. Therefore, since the eight characteristic roots of the collector 20 are on the points (-0,128, j±12.34), (-1.212, j±121.84), (-1.88, jO), (-23.69, jO), (-27.67, ±j98.19) in the complex coordinate, the seven observer characteristic roots of the state s estimating unit 236 are determined on the complex coordinate in such a manner as follows. That is to determine the roots of the matrix (A-Le, C) in the equation (Equation 4)
(-6.0, ±j12.34), (-23.69, j+0), (-27.67, ±j98.19), (-60, j±121.84)
As can be understood from these points, the roots, (-6.0, ±j12.34) and (-60, j±121.84), are determined such that the damping characteristics for the two roots depending on the disturbance, (-0.128, j±121.84) and (1,212, j±121.84), are improved (ζ=0.01 0.44).
A method for active control of the disturbance suppression force using the contact force observer unit 233 will be described next. The equation of the state for the collector 20 including the external force of the trolley wire 1, the lift force and so on is expressed as follows:
d/dt(X)=AxX+BxU+DxW (Equation 5)
f=CxX+ExW (Equation 6)
Wherein, X is a state value y 1 , y 3 , y' 1 , y' 3 , z, z', z", z'") vector, the pushing-up force vector u=HxR, r being a control signal vector, H being a vector constant, f being an output scalar for the contact force, W being an input scalar of the disturbance, A being an 8×8 matrix, B being an 8×1 vector, C being a 1×8 vector, D being an 8×1 vector, E being a 1×8 vector.
And, the equation of state for the normal difference compensating unit 232 is expressed as follows.
d/dt(Q)=FxQ+G(f*-f )
Then, the following equation can be obtained.
Q=k.sub.2 (f*-f ) (Equation 7)
Wherein, k 2 is the normal compensating gain vector, Q is an output state value (1×1) vector of the normal difference compensating unit 232, F being a scalar constant, G being a vector constant, (f*-f ) being an input scalar to the force difference value control signal. ##EQU2##
Therein, k 1 ' and K 2 are vector constants, and there are the relationships K 1 =-Hxk 1 ' and K 2 =H. From Equation 5-Equation 8, all the equations of state for the optimum contact pressure target value f* and the contact pressure f and the push-up force u are expressed as follows. ##EQU3## Therein,
X=[y.sub.1, y.sub.3, y'.sub.1, y'.sub.3, z, z', z", z'"].sup.T (Equation 9) ##EQU4##
Thus, using Equation 7 through Equation 10, the contact force can be decreased by inputting said control signal r for the pushing-up force u (Equation 8) based on fa and f to the servo control device 240, fa and f are obtained through inputting said control signal of the varying force signal fx and the push-up force u to the contact force observer unit 233. The disturbing compensating gain k 1 ', the vector constant H and the compensating vector F/G used at this time are required to be selected properly.
FIG. 31 shows a structure of the current collector driving system 244 which receives said control signal r to output the pushing-up force u. The system 244 is composed of an amplifying circuit 242 to amplify said control signal r, a servo valve 243 to control the oil pressure from an oil-hydraulic pressure source 241, a driving cylinder 32 and a driving rod 31 to produce the pushing-up force u by the action of expansion and contraction caused by the servo valve 243.
Although an oil-hydraulic pressure source 241 is used in this example, a compressed air source may be used, as described later, when the response of the servo valve and cylinder is fast enough. In this case, the transfer characteristic of the pushing-up force u corresponding to said control signal r is required to be of the same order.
FIG. 32 is a block diagram showing the operation of the two containing systems 360a and 360b to lower and house the collector head 22 in the containing dome 4, wherein the two rods for raising and lowering 8a and 8b are operated to expand and contract and the collector 20 is operated to rotate through the rotating system 40. The two containing systems 360a and 360b are composed of amplifiers 361a and 361b. switching valves 362a and 362b, cylinders for raising and lowering 7a and 7b. When the containing systems receive the operation signal from the controller for raising and lowering 364 installed in the containing dome 4, the containing systems are operated with oil-hydraulic pressure from the oil-hydraulic pressure source 363 to raise the current collector 20 perpendicular to the car body 2 with the rods 8a and 8b, as shown in FIG. 18, so as to collect current from the trolley wire 1. On the other hand, when the current collector 20 is to be lowered, the containing system disconnects the contact strip from the trolley wire 1 and lowers it into the containing dome 4 using the projecting rods 8a and 8b, as shown in FIG. 19.
Another embodiment of the present invention may be realized with use of motors for driving the current collector 20 instead of oil-hydraulic pressure.
For a comparatively low running speed vehicle, the shutter system for the containing dome 4 is not required. Since the containing dome 4 itself has a substantial effect to decrease noise, the opening, through which the current collector 20 is put out or into, may be kept open.
FIG. 33 shows a further embodiment of the present invention where a high voltage flexible cable 44 for current conducting is held in the hollow portion of the supporting insulator 30. A conductor 53 is installed in the inside of the insulator to support a collector head 22. In other words, a cable head for current conduction supports the collector head 22. The high voltage flexible cable 44 is drawn out of the side of the insulator 30. The collector head 22 is fixed with a nut and a screw which is formed on the top end of the current conductor in the cable head 22. Therewith, there is an advantage in that a structure having only one insulator can be realized.
However, it is undesirable for the life of the high voltage flexible cable 44, since the high voltage flexible cable 44 moves upward and downward accompanied with the operation of the driving rod 31.
FIG. 34 shows another embodiment of the present invention which is applied to a current collecting system of a third rail type.
In this embodiment, the present invention is applied to a vehicle which collects current from a third rail installed on the side of the rail-way instead of current collecting from a trolley wire installed above the vehicle.
The current collecting of this type is widely used for a subway vehicle, wherein the positive voltage is applied to the third rail 76 installed on the side of the rail-way to miniaturize the tunnel cross section, and a negative voltage is applied to the rails 75 on which the vehicle runs. The third rail 76 is insulated with insulators 77. Current collecting is performed by pushing a current collecting shoe 73 against the third rail 76.
There is an insulator 72 on the vehicle side of the current collecting shoe 73 to insulate the high voltage from the vehicle, and there is an oil-hydraulic cylinder 71 on the further vehicle side to control the pushing force for the current collecting shoe 73. The oil-hydraulic cylinder 71 is fixed to an axle box body or a bogie frame 70 having small displacement with respect to the rails 75. The electricity collected by the current collecting shoe 73 is transferred to a cable head 78 through a flexible conductor 74 and then is supplied to a control system installed on the vehicle 2.
FIG. 35-FIG. 37 show a further embodiment of the present invention. In this embodiment, the current collector 20 is rotatably flatted rearward with respect to the running direction. There are cylinders 7 and a connector 6 on the front side position in the running direction indicated with an allow. A high voltage flexible cable 44 is positioned between the branches of a hinge supporting the current collector 20. The domes 4A, 4B, 4C are inversely positioned in the running direction with respect to the embodiments described above.
Therein, when the current collector 20 is housed in the containing dome 4, the vertex of a triangle of the collector head 22 comes to the upper side. Therefore, the size of the containing dome 4 can be miniaturized as compared to the embodiments described above, which decreases the running resistance. This can be easily seen from a comparison of FIG. 37 with FIG. 5, for example.
Although the supporting insulator 30 is kept standing upright during running in the above embodiments, it is possible that the tilting angle of the support insulator 30 may be varied corresponding to the running speed by operation of the cylinders 7 for raising and lowering the current collector to control the wing force. In this case, it is desirable that the current collector contact strip 21 and the collector head 22 are formed to be arc-shaped. Further, when the wind from the containing dome strongly affects the current collector 20, it is desirable to move the current collector 20 toward the running direction.
Since the lift force acts on the collector head 22 during high speed running, the collector head 22 is controlled such that the top front of the collector head 22 is directed slightly downward using the cylinder 7. In FIG. 32, the controller for raising and lowering 364 operates the cylinder 7 such that the top front of the collector head 22 is directed slightly downward when the vehicle runs faster than a given running speed using the running speed information from a controller on the vehicle. And, the command from a central operation room is also used.
Since the lift force becomes large when the vehicle is passed by another vehicle in a tunnel, the collector head 22 is similarly directed downward. When the vehicle enters into a tunnel at a high speed, the collector head 22 is also directed downward. In FIG. 32, the controller for raising and lowering 364 operates the cylinder 7 using the running position information from the controller on the vehicle or the command from the central operation room.
Furthermore, a baffle plate may be placed at the back of the cable head 50 to straighten the air flow downstream of the cable head 50. The baffle plate is preferably made of an insulating material and attached to the mounting base 55 for the cable head 50.
It is desirable to provide an emergency ground switch EGS in the current collector 20. That is, as shown in FIG. 39, an emergency ground switch EGS 300 is installed parallel to the cable head 50 in the current collector 20. The emergency ground switch EGS has a copper rod 303 driven by a cylinder mechanism 302 operated by a compressed air source 301. The copper rod 303, which is normally in the containing dome, is projected from the containing dome in response to a driver's emergency operation to connect its upper end to the collector head 22 through a clip 304, as shown in the figure. The numeral 305 indicates a braided copper wire connected to the base plate 3. The emergency ground switch EGS has the function on to shunt the vicinity of the collector head 22 to the ground as fast as possible in an emergency. The emergency ground switch EGS cylinder mechanism 302, which is formed with the cylinder 32 as a unit, is rotated to be raised or lowered together with the supporting insulator 30 and the cable head 50 by the rotating system 40.
In accordance with the present invention, it is possible for the cable head 50 for current conduction to be installed with a mechanism allowing it to tilt to make the high voltage cable easily movable. When this is done, the cable head 50 for current conduction is not parallel to the support insulator 30, which decreases the standing wave produced between them and thus further decreases noise.
According to the embodiments of the present invention described above, a part of the structure having a current collecting function can be light in weight and small in size and can improve the control characteristic to follow the trolley wire 1, since the part of the structure having the current collecting function, which comprises the current collecting member and the driving system, is installed separately from the part of the structure having the power current conducting function, which can, further, maintain the powerscurrent collecting function sufficiently.
Furthermore, the generation of noise during vehicle running can be suppressed, since there is provided a containing system on the roof of the vehicle inside of which the driving system is always contained and in which the part of the structure having the current collecting function together with the part of the structure having the power current conducting function is contained when it is not needed.
Referring to FIG. 40 through FIG. 51, various features of the current collector 20 and its performance will be discussed. In FIG. 40, the current collector 20 comprises a current collecting contact strip 21 to collect current from a trolley wire 1, a collector head 22 having a front portion in the running direction which is swept back in its longitudinal direction to mount the current collecting contact strips 21, a supporting column 400 having a stream-line shape to support the collector head 22, an insulator 500 to insulate electrically the vehicle body 2 from the current collector 20 and driving means (not shown) for driving them vertically.
Since the contact strips 21 and the collector head 22 of conventional current collectors 20 are formed of two dimensional shaped members, such as circular bars, a two dimensional vortex typical of a Karman vortex is easily generated, and so a large aero-hydraulic noise and a large air resistance is also generated, which has been a problem for high speed running. Since the stream-line shaped current collector proposed to dissolve this problem suppresses generation of a Karman vortex as compared to the non-stream-line shaped current collector, the noise can be lowered. However, since the current collector 20 has, even in this case, long members in the direction perpendicular to the running direction, the flow is apt to become two-dimensional. Therefore, even when the collector head is formed in a stream-line shape, the degree of generating aerodynamic noise has been large.
Although the noise for the stream-line shaped current collector 20 is lower the that for the non-stream-line shaped current collector 20, a further low noise current collector 20 has been desired for low noise high speed running.
Since the current collector 20 according to the present invention provides a collector head 22 having a front portion in the running direction which is swept back in its longitudinal direction, longitudinal vortexes are generated around the collector head 22. The longitudinal vortexes suppress generation of a vortex having a two dimensional structure typical of a Karman vortex. FIG. 41 and FIG. 42 illustratively show the flow around collector heads, a collector head 305 (FIG. 41) according to the present invention and a wing-shaped collector head 306 (F,G.42) used in a general stream-line shaped current collector 20. In the current collector 305 according to the present invention, the longitudinal vortexes suppress the vortexes with synchronized phase which are apt to generate noise, and consequently suppress generation of noise.
FIG. 43(a) through FIG. 44(b) illustratively show pressure distribution on the surfaces of collector heads. In the conventional two dimensional wing 308, as shown in FIG. 44(a), since the wake is two dimensional, the pressure on the surface is also uniform and two dimensional along the longitudinal direction of the wing 308, as seen in FIG. 44(b). On the other hand, in the collector head 307 having a sweep-back front end surface according to the present invention, as shown in FIG. 43(a), since the pressure distribution is not uniform along the lateral direction of the collector head 22, as seen in FIG. 43(b), the noise is hardly generated.
In order to lower the aerodynamic noise generated by the flow around the connecting portion between the collector head 22 and the supporting column 400, the connecting portion between the collector head 22 and the supporting column 400 is formed with a curved surface, as shown in FIG. 45. Stated in another way, the connecting portion is formed with a polygon surface such that the connecting portion has no acute angle. When the connecting portion between the collector head 22 and the supporting column 400 has an acute angle or a right angle, there appears a secondary flow there to generate aerodynamic noise. Since an abrupt change of flow in the vicinity of a wall surface is apt to generate noise, employing the connecting portion according to the present invention decreases noise. Especially, when the length S 2 of the portion where the smooth surface contacts the collector head 22 is nearly one third of the length S l of the collector head 22 in its longitudinal direction and the length S 3 between the bottom surface of the collector head 22 and the portion where the smooth surface contacts the supporting column 400 is nearly one sixth of the length S 1 of the collector head 22 in its longitudinal direction, the effect to lower the noise is large.
FIG. 46 shows the result on noise obtained from a wind tunnel test using a model of a current collector 20 according to the present invention, as well as showing the result of a conventional current collector 20 for comparison. The current collector 20 according to the present invention (circles) lowers the noise by approximately 20 dB compared to the conventional current collector, and by more than 5 dB compared to the streamline shaped current collector.
It is also preferable that the collector head 22 has a shape where the cross section of the collector head is wing-shaped and the front faces on both sides of the collector head are swept back. For the collector head 22 having such a shape as described above, since the edges are swept back to the collector head, the contact strip 21 on the edge line will not generate vortexes which are uniform and have synchronized phase, and consequently the noise is lowered.
In FIG. 47, collector head 22 has the shape of a rhombus (in plan view) formed by combining two collector heads having front faces on both outer sides 22A swept back against the central portion 22B fore and aft. That is, the collector head is symmetrical in the fore and aft directions and has a shape where the front edges are swept back in the longitudinal direction from the center of the collector head, which realizes a low noise current collector 20 generating a longitudinal vortex which is symmetrical fore and aft.
The both side ends of the collector head 22 are formed in convex curved surfaces on the upper surface side contacting the trolley wire 1 so as to minimize generation of wing top vortexes and so as to guide crossover.
There is a further aspect of the present invention in which the effective length of the contact strips 21 are changed depending on low or high speed running and corresponding to the running direction. During a low speed running, the effective length of the contact strip 21 is long to cope with a trolley wire change and the like. On the other hand, during high speed running, the shape of the collector head 22 changes into a shape suitable for decreasing noise.
There is another aspect of the present invention wherein a turntable is installed to mount a current collector 22 and rotate the current collector 22 corresponding to the running direction of the vehicle. By employing this technology, the number of the current collectors 20 to be mounted on the train can be decreased.
FIG. 48 shows another form of the current collector 20 in which the collector head 22 has its maximum vertical thickness (h max ) position P of the wing shaped cross section located more than 30 percent of the chord length (C) from the front edge of the wing-shape, and the upper surface of the collector head 22 in the vicinity of the rear edge is a concave curved surface. In the case where the collector head 22 has such a shape as described above, it has been confirmed that the pressure drop from the maximum pressure point to the rear end is gentle and the aerodynamic noise is decreased. Therefore, the collector head 22 having this cross sectional shape according to the present invention is effective to decrease noise. Further, the collector head having a symmetrical shape to the horizontal line has had a high effect.
FIG. 49 shows a further form of the current collector with a support column 400 for the collector head 22 having a shape of a circular cone or elliptic cone 400a, which hardly will cause aerodynamic noise. Therewith, the flow around the supporting column varies in the vertical direction to make the flow three dimensional and to suppress the generation of noise.
FIG. 50 shows another form of the current collector of the present invention. When the contact strip 21 is of a two-dimensional shape, a large aerodynamic noise is generated. In this case, at least one or more projections 222 having a long shape in the running direction of the vehicle are provided at the positions narrower than the contact strip 21 in the vicinity of the front edge forward of the contact strip 21 on the collector head 22, and longitudinal vortexes are generated with these projections to suppress the Karman vortex-like aerodynamic noise caused by the contact strip 21. Especially, when more than three of the projections 222 are attached to the width of the contact strip 21, the effect to decrease noise is large.
FIG. 51 shows a result of a wind tunnel test for studying the noise decreasing effect of the present invention. The projections 222 for generating a longitudinal vortex according to the present invention is effective for decreasing noise.
According to the present invention, it is possible to decrease aerodynamic noise in a current collector for a high speed railway vehicle by using a collector head having a swept-back shape in its longitudinal direction so as to actively generate longitudinal vortexes on the collector head to suppress generation or the two dimensional vortex having a synchronized phase, that is to say, a vortex which is apt to generate aerodynamic noise, such as generated in a conventional current collector. Further, it is possible to decrease the aerodynamic noise produced from the connecting portion between a collector head and a supporting column by not only forming the collector head and the supporting column in stream-line shapes, but also smoothly connecting the collector head and the supporting column so as to suppress generation of a secondary flow at the connecting portion of the collector head and the column so as not to interfere with the longitudinal vortexes generated by the collector head.
According to another feature of the present invention, it is possible to decrease the aerodynamic noise caused by a two dimensional flow produced by the current collector by generating a three dimensional flow using a duct to generate a swirl flow.
According to a further feature of the present invention, parts of the collector head are movable so as to provide a function to guide the crossover of the trolley wire during low speed running and to provide a shape for low aerodynamic noise by flatting the collector head to lower noise during high speed running. With the structure, it is possible to obtain a shape which is low in noise generation during high speed running with no problem in changing the trolley wire during low speed running.
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A current collector for a railway trolley vehicle includes a current collecting member having a contact strip, a driving system for moving the current collecting member into and out of contact with a trolley wire, a load cell for detecting force acting between the current collecting member and the driving system, a displacement meter for detecting displacement of the driving system, first and second estimating circuits, and a control circuit. The first estimating circuit provides an estimated value of the contact force between the current collector and the trolley wire by estimating values of first parameters of the contact strip, the current collecting member, and the trolley wire and summing products of each of these values and a corresponding weighting factor. The second estimating circuit provides an estimated value of a disturbance suppressing force by estimating values of second parameters of the contact strip, the current collecting member, and the trolley wire and summing products of each of these values and a corresponding weighting factor. The control circuit calculates a difference force value by subtracting the estimated contact force value and the estimated disturbance suppressing force value from a contact force target value. The control circuit then adjusts a pushing-up force of the driving system on the basis of the calculated force difference value.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention, in general, relates to switching arrangements for logic circuits clocked at a very high frequency and to methods of clocking these logic circuits. More particularly, the invention relates to sequential circuits for integrated circuits which operate at very high clock frequencies.
2. The Prior Art
A known principle of structuring clocked logic circuits or sequential circuits of the kind depicted in FIG. 1 consists of connecting the data outputs of storage units or registers which are synchronously controlled by a clock, to the inputs of blocks of gates (a term which in the present context is intended also to include inverters) and of connecting, in turn, the outputs of the logic circuits to the input of registers, and so forth. Finite state machines as well as synchronously clocked data flow machines often make use of this principle. In such an arrangement, a subsequent register may be wholly or partially identical to the preceding one, so that cyclic feedbacks are generated.
The shorter the maximum time delay of a pass from a register through the signal path of the logic block to another register, the higher may be the selected clock rate and, hence, the processing power of such a clocked circuit. The maximum time delay of a clock cycle consists of the maximum duration of the signal passage through the block in the least favorable case (on the critical path) as well as the maximum time delays and, optionally, the necessary lead times of the registers utilized.
In circuits of this kind, the registers are necessary for interrupting the signal flow until all output signals of the logic circuit, which may obviously be subject to different time delays in the various paths, are valid and which at this instant store the signal for further transmission.
In simple logic functions of short signal passages through a given path of the block the maximum time delay for a clock cycle is essentially defined by the time delays of the registers. For that reason, a number of circuits seeking to reduce the time delay of registers have been developed (for instance U.S. Pat. No. 4,057,741).
OBJECTS OF THE INVENTION
It is, therefore, an object of the present invention to provide clocked circuits of very low time delays or very high data throughput.
It is a further object to provide logic circuits clocked at a high frequency and which require no registers for clocking the signal passage.
SUMMARY OF THE INVENTION
In accordance with a currently preferred embodiment this clocking is achieved by connecting at the output of a gate of the logic circuit an additional current source, hereinafter sometimes referred to as “clocked current source”, in parallel to the output of the corresponding gate. The output current of the additional current source is controlled by the frequency of a clock. The gate has one output and, in a generalized case, N inputs.
BRIEF DESCRIPTION OF THE SEVERAL DRAWINGS
The novel features which are considered to be characteristic of the invention are set forth with particularity in the appended claims. The invention itself, however, in respect of its structure, construction and lay-out as well as manufacturing techniques, together with other objects and advantages thereof, will be best understood from the following description of preferred embodiments when read in connection with the appended drawings, in which:
FIG. 1 is a schematic plan view of a prior art clocked logic circuit;
FIG. 2 is a block diagram depicting a circuit arrangement in accordance with the invention;
FIG. 3 is a graph depicting the time characteristic of the output voltage of a circuit in accordance with the invention;
FIG. 4 is a schematic plan view of a first embodiment of a circuit in accordance with the invention; and
FIG. 5 is a schematic plan view of a second embodiment of a circuit in accordance with the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The load capacity present at the output junction (A) has not been shown in FIG. 2; but its effect will be taken into consideration in the following description. Voltage changes at the output junction (A) require charge or discharge currents of the load capacity present at A. This is achieved by the temporally variable output current which is the sum of the instantaneous output current i2 of the current source 22 and of the instantaneous output current i1 of the gate 21 . In other words, the gate itself will hereafter also be considered as a variable current source rather than as a variable current source with a load-depending delay, of the kind often used in digital circuit technology.
FIG. 3 schematically depicts an example of the time characteristic of the output voltage (voltage axis: V, time axis: t) of such a gate clocked by an additional current source.
For simplifying the description let it be assumed that when switching the output of the gate towards a positive operating voltage, the output current i1of the output stage of the gate will be at a constant value I1 (i1=I1) as long as the output voltage has not fully reached the value of the positive operating voltage (Vdd in FIG. 3 ). When this condition has been reached, the output current may be assumed to be zero (i1=0).
The same assumption will be made as to switching the output of the clocked current source towards the positive operating voltage: Until the positive operating voltage has been reached, the output current i2 of the clocked current source 22 is assumed to be of constant value I2 (i2=I2); thereafter its value is assumed to be zero (i2=0).
Inversely, when switching from, or discharging, the negative operating voltage (0 in FIG. 3 ), it is to be assumed that what has been said supra holds true as well, albeit with negative signs (i1=−I1, i2=−I2), for the two outputs, since it is a discharge of the load capacity at A. In this case too, the output currents are each assumed to be zero (i1=0, i2=0) again, when the negative operating voltage has been reached. Furthermore, it is to be assumed that the constant value 11 is higher than the constant value I2, for instance twice as high (I1=2×I2).
FIG. 3 depicts the condition of the output stage of the gate commencing its switching earlier than the clocked current source. In this case let it be assumed that both current sources are initially switched to discharge. Initially, no current is flowing as the output voltage has already reached the value of the negative operating voltage.
In FIG. 3, instant t 1 denotes the instant at which the output stage of the gate switches so that its output current is i1=l1. This causes a small shift of the output voltage away from zero, so that current is immediately contributed from i2as well. However, initially the clocked current source remains switched to discharge so that its current is negatively biased (i2=−I2). The resulting output current is the sum of both currents; that is to say, because of the opposite bias it is the difference of the values (i1+i2=I1−I2). For that reason, the output voltage at this time increases only slowly: Compared to switching only by the unclocked current i1of the output stage of the gate, its increase amounts to the fraction (I1−I2/I1) only of the original increase. In the mathematical example (I1=2×I2), this fraction would be 50%, so that in this phase the change in output current and, hence, the transmission of the signal would be slowed to half the original velocity.
In FIG. 3, the instant t 2 denotes the instant at which the clocked current source switches so that its output current is i2=l2. The resulting output current again is the sum of the two currents; because of the same bias it is, therefore, the sum of the values (i1+i2=I1+I2). Hence, the output voltage now increases significantly more quickly: compared to switching by means of the current l1 of the output stage of the gate only, its increase now amounts to the factor (I1+I2)/I1 of the original increase. In the mathematical example (I1=2×I2, this factor would be 150% so that in this phase the change in the output voltage and, hence, the transmission of the signal would be accelerated to one and a half times the original velocity. In the case of coincidence the effect of the two current sources would thus be substantially stronger than where they do not act simultaneously (i.e. by the factor (I1+l2)/(l1−l2). In the mathematical example, the factor equals 3.
The positive operating voltage has been reached at instant t 3 , and both currents decay to zero.
By appropriately dimensioning the current source relative to the output resistance or output current of the gate, the instant at which the switching threshold of the following gate and, hence, the instant in time at which the signal is transmitted to the next gate may be defined, within certain limits, by the input clock sequence. Thus, individual differences in the time delays of the gates may be equalized and these time delays may be conformed to the clock rate.
Not only are delays of the signal possible relative to the through-put time of a gate which is not influenced by the input clock sequence (where the summing currents flow in opposite directions), but also by accelerations (where the currents flow in the same direction).
In this manner, the clock sequence substantially contributes to defining the rate of charge of the output capacity. Substantially phase-locked through-puts of the signal levels relative to the corresponding instants in time at which the control clock sequences switch may in fact be attained by the input switching threshold at the outputs of the clocked gates, thus resulting in clock sequence synchronization without necessitating an interruption in the signal path or in a register.
Compared to a conventional circuit provided with registers, a circuit in accordance with the invention may, on the one hand, operate faster because registers are no longer required and, hence, delays are avoided, and, on the other hand, it is even possible to achieve a further acceleration relative to the minimum through-put time of an unclocked circuit, by the addition of coincident partial currents.
The simplified case of constant current values discussed thus far is no precondition as to the functionality of the logic circuit clocked in accordance with the invention; rather, it is a simplification for purposes of a comprehensible description. In actuality, the output current of the output stage of the gate usually does not only not act as a constant, but also non-linearly as a function of input value and time. On the other hand, clocked current sources may also display a non-linear behavior. In such cases, too, a correct logical function of a gate may be obtained by clocking.
As regards the suitability of a circuit as a clocked current source it is essential, among other things, that its output current may be changed sufficiently quickly with the input clock sequence.
Aside from gates other switching components may also be provided with such a clocked current source. This may, for instance, be a retarding circuit without logical change of the signal.
A complete logic circuit unit includes partial blocks in each of which all clocked current sources are controlled by a clock sequence of equal cycles (or frequency). This may be accomplished by connecting the control inputs of all clocked current sources of a block of the same clock sequence; however, several clock sequences may be used which may be supplied, for instance, at equal frequencies from different driver stages. In this manner, blocks may be provided, for instance, in which each clocked component has a delay defined by the same clock frequency, so that the signal flow displays an easily discernible time pattern.
A circuit unit may contain logic partial blocks in which each of the clocked current sources which are part of one block are controlled by an individual clock sequence the period k×t 0 of which is a whole number multiple of a base periodicity t 0 of the given block. In this context, k is a whole number. Whereas t 0 is constant in the entire block, k may change from one clock sequence input of a clocked current source to another. It is thus possible within a single block to operate at different time delays of the clocked components.
This may be of advantage, for instance, for utilizing, in one block, gates of vastly different complexity the delay time of which would not have to be brought into uniformity by clocking.
In such a cases, the common base periodicity simplifies the design as it allows in a simple manner to form synchronously switching junctions in the signal paths.
In order to continue applying the design strategy of the structural principle of logic circuits described above which is based upon logic blocks and registers (see FIG. 1) while at the same time avoiding registers by means of the clocking in accordance with the invention and increasing the through-put rate, it is necessary to ensure that—but for a certain admissible residual error—the signal through-puts in each path of the block are of the same time delay.
This is accomplished by structuring the signal paths such that for each signal path through the block the sum of the cycles of the clocked current sources pertaining to the outputs of the components of this path is the same. By appropriately dimensioning the clocked current sources and/or the output stages of the gates it will then be possible to attain a substantially identical total time delay of the paths.
An example of a basic concept of such a circuit is depicted in FIGS. 4 and 5. It is based upon the exemplary circuit of FIG. 1 albeit changed into a circuit with a substantially similar logic function but with a much higher clocking rate.
In this example, clocking of identical cycles t 1 is to be utilized for all clocked gates of the block. Moreover, all gates of the block are to be clocked. For the longest signal paths through the block 12 in FIG. 1 which extend through three gates, clocking would result in a cycle sum of 3×t 1 .
In order for the cycle sum of all paths to be identical as shown in FIG. 4, additional gates are first inserted in the shorter paths of the block ( 42 ) without changing the logic function. By comparison to FIG. 1, two successive inverters have been added to each of three paths in FIG. 4 .
Each path now extends through three gates and, given a connection of appropriately dimensioned clocked current sources all of which are controlled by the same cycle duration t 1 , the sum of the cycle durations for each path is 3×t 1 . FIG. 5 depicts an example of a circuit including the gates in accordance with FIG. 4 to the output of each of which there is connected a clocked current source. The registers 41 and 43 in FIG. 4 at the exterior connections of the block ( 52 ) have been replaced by direct connections ( 51 and 53 ). In the design, the direct connections may be considered as “virtual registers”.
To simplify the circuit diagram a symbol has been drawn in FIG. 5 for the clocked current source associated with the block 52 , i.e. a small vertically disposed isosceles triangle with an upward vertical connection which is to symbolize the output of the current source. In the lower left portion of FIG. 5 symbol has been explicitly depicted again ( 54 in FIG. 5 ), in addition to the clocked current sources associated with the block 52 . For purposes of simplification, the connection of the control inputs of the current sources to a clocking sequence of equal cycle duration has not been shown. By fabricating this circuit on an integrated circuit by the same semiconductor technology as the original circuit of FIG. 1, it is possible at an appropriately selected circuit layout to achieve a substantially higher clocking rate than with a circuit of the kind shown in FIG. 1 . Since elimination of the registers results in the elimination of relatively complex objects of the kind necessitating a significant layout, the requirement for chip surface of the two designs may be comparable in spite of the many additional clocked current sources.
A further substantial advantage of velocity or through-put rate results from the utilization of a clocked circuit in clocked data flow machines.
As regards the through-put rate in clocked data flow machines it is not the time delay of the entire logic block to the next “virtual register” which is decisive, but the clocking rate at which the signals may be applied to the input of the block. The clocking rate may be defined by the clocking rate of the clocked current sources of the individual clocked components of the block in accordance with the invention, so that a successive input signal may be received by the block long before a prior input signal has been processed and before it appears at the output of the block.
The clocked current sources may be formed by transistors operating in a push-pull mode. In that case, a known amplifier circuit of the kind frequently utilized as a voltage amplifier, is used as a controlled high-frequency current source. In the simplest case, this may be an inverter circuit of the kind known from digital circuit technology, the transistor geometries of which must, however, be tuned for use as a clocked current source relative to the transistor geometries of the clocked output stage.
The clocked current sources may also include a single-ended amplifier, as, for instance, where no complementary transistors are available and where a push−pull amplifier may not reasonably be used for such purpose. For purposes of the invention, a suitably dimensioned inductance within or at the load circuit may optionally, at high frequencies, functionally replace the effect of a complementary transistor controlled in a push-pull mode as a controllable current source.
Since each of the clocked current sources need operate only in one defined frequency range (the range of the controlling pulse), it is possible with the inductance in a favorable way to form a resonant circuit tuned to this frequency which may include additional electrical capacitances as well as existing parasitic capacitances.
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Circuit arrangement, and a method of its operation, for substantially reducing the running times in clocked logic circuits by eliminating conventional storage registers and by controlling the signal flow by parallel connection to the output of a gate or other signal transmitting circuit component of an additional current source which may be changed by the clock pulse.
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TECHNICAL FIELD
The invention concerns providing wave dispersive and energy dispersive x-ray fluorescence spectrometry capability in a single device.
BACKGROUND OF THE INVENTION
X-ray fluorescent spectroscopy (“XRF”) is typically conducted using a wave dispersive spectroscopy (“WDS”) or an energy dispersive spectroscopy (“EDS”) method. WDS utilizes Bragg diffraction and a precisely placed x-ray detector to determine the intensity of x-rays fluoresced from a sample as a function of wavelength. Because chemical elements have characteristic fluorescent spectra, the information derived from WDS can be used to perform quantitative analysis of the sample's elemental content.
Conversely, EDS samples fluorescent x-rays from a sample without intervening diffraction, and measures x-ray flux as a function of energy. EDS x-ray detectors are typically less expensive than WDS detectors, but also provide lower resolution than WDS detectors. Further, EDS systems are typically less expensive to manufacture, providing a lower-cost alternative to WDS systems.
Because WDS and EDS systems have relative strengths and weaknesses, it is often desirable to have both systems available to perform a full range of XRF analysis on a sample. To somewhat reduce the expense and space requirements of doing so, hybrid WDS/EDS systems have previously been proposed.
For example, U.S. Pat. No. 5,978,442 to Kuwabara discloses an XRF system combining the elements of both WDS and EDS. That system includes a dispersing element used to disperse fluorescent x-rays toward a first x-ray detector, which is utilized in a WDS mode. By retracting the dispersing element from the fluorescent x-ray flux, the flux can be allowed to pass through to a second x-ray detector, which is suitable for and used to conduct EDS measurements.
Similarly, U.S. Pat. No. 4,959,848 to Parobek discloses a hybrid system for determining the thickness of a thin film and quantitative measurement of at least some of its elemental content. This system also involves the use of multiple detectors which are dedicated to either WDS or EDS measurements.
U.S. Pat. No. 6,285,734 to von Alfthan discloses a hybrid WDS/EDS system which requires multiple detectors, including individual monochromators, detectors, and measuring electronics for each element sought to be measured through WDS. Although this system can reduce the time for making measurements by eliminating the need to rotate the WDS x-ray detector through a range of angles, it also multiplies the equipment cost necessary to achieve the desired measurements.
Each of these systems attempts to provide both WDS and EDS measurements through a single apparatus. Such systems may reduce total requirements for laboratory space and utilities needed for operation, but they retain the expense of multiple detection systems, and each apparatus must be large enough to accommodate at least two sets of detectors with their appropriate hardware.
Thus, it is desirable to provide an apparatus capable of performing both WDS and EDS utilizing a single x-ray detector, thus reducing space requirements and overall cost of the apparatus. Further, such an apparatus can be efficiently switched from WDS mode to EDS mode or vice versa, providing great flexibility in utilizing the device to perform needed measurements.
BRIEF DISCLOSURE OF THE INVENTION
As is typical in XRF spectroscopy, the sample from which measurements are taken is irradiated by an x-ray source, producing a flux of fluorescent x-rays from the sample's surface. In WDS mode, the fluorescent x-ray flux is directed through a collimator and then to the surface of a rotatable crystal. For this invention, the rotatable crystal is preferably a multi-layer crystal such as OV-055A produced by Osmic, Inc. The fluorescent x-ray flux undergoes Bragg diffraction in the surface region of the rotatable crystal.
The invention also comprises an x-ray detector, mounted on a goniometer. In the preferred embodiment, the x-ray detector is a PIN diode detector such as PF1000 produced by Moxtek. Such a detector may be switched from a pulse mode to a cascade mode, allowing the detector to be used to perform WDS in pulse mode and EDS in cascade mode. This mode-switching capability increases the counter's efficiency in each mode.
The goniometer provides controlled rotation of the x-ray detector about an arc. In WDS mode, the goniometer and the rotatable crystal are linked so that rotation of the rotatable crystal through an angle θ will move the detector through an angle 2θ, thus maintaining the required positional relationship for measurements resulting from Bragg diffraction.
The goniometer is also aligned so that positioning at one of its endpoints of rotation positions the x-ray detector collinear with the fluorescent x-ray flux from the sample. In this position, the surface of the rotatable crystal is parallel to the fluorescent x-ray flux, so that the rotatable crystal no longer interacts with the x-ray flux. In this position, the detector is preferably switched to cascade mode for the purpose of performing EDS. To provide sufficient x-ray flux during EDS operations, it is preferred that the collimator is retracted from the x-ray flux, either by linkage to the goniometer or by another mechanism which provides for movement of the collimator.
To perform WDS, the x-ray detector is switched to pulse mode and rotated by the goniometer out of the EDS position. The linkage between the goniometer and the rotatable crystal will simultaneously bring the rotatable crystal into position so that Bragg diffraction occurs. In WDS mode, the collimator is inserted into the fluorescent x-ray flux.
It is also preferred that the total 2θ range of the goniometer is restricted to approximately 50°. Although goniometers with greater range are available and although this limit may preclude exhaustive WDS analysis, this range of motion will provide adequate implementation of WDS for most purposes and allows the overall size of the apparatus to remain within desired limits.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A is a schematic view of an embodiment of the invention positioned for WDS measurements.
FIG. 1B is a schematic view of the same embodiment of the invention positioned for EDS measurements.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIGS. 1A and 1B, schematic views of an embodiment of the invention positioned for WDS and EDS measurements, respectively, are shown. An x-ray source 10 irradiates a sample 12 with a flux of x-rays 24 , producing a fluorescent x-ray flux 26 from the sample 12 . In WDS mode, as depicted in FIG. 1A, the fluorescent x-ray flux 26 is directed through a collimator 27 and then to a rotatable crystal 14 , which is preferably a multi-layer crystal. The fluorescent x-ray flux 26 is incident to the rotatable crystal 14 at an incidence angle 28 , generally denoted as θ. The fluorescent x-ray flux undergoes Bragg diffraction by interaction with the rotatable crystal 14 , resulting in a diffracted x-ray flux 30 which is detected by an x-ray detector 18 . In the preferred embodiment, the x-ray detector 18 is a PIN diode detector and is operated in pulse mode while performing WDS measurements.
The x-ray detector 18 is moved along an arc 22 by a goniometer (not shown). The motion of the x-ray detector 18 is coupled to the rotation of the rotatable crystal 14 about axis of rotation 16 so that x-ray detector 18 moves through a change along angle 32 of 2Δθ for every Δθ change in incidence angle 28 . Angle 32 is the angle between the original path-line 34 of the fluorescent x-ray flux 26 and the path-line 31 of the Bragg-diffracted x-ray flux 30 . The x-ray detector 18 is movable between first and second endpoints 19 and 20 for purposes of making WDS measurements. At second endpoint 20 , the x-ray detector 18 is collinear with the original path-line 34 of the fluorescent x-ray flux 26 , and will thus be in position for performing EDS measurements. In the preferred embodiment, the range of movement of the x-ray detector 18 along arc 22 is limited to about 50°, which is sufficient to provide adequate WDS measurements, yet allows the apparatus size and cost to be held within reasonable limits.
As depicted in FIG. 1B, for EDS measurements the x-ray detector 18 is positioned at second endpoint 20 along the arc 22 . In this position, the rotatable crystal 14 is positioned so that its surface 15 is parallel to the fluorescent x-ray flux 26 , so that Bragg diffraction no longer occurs. It is also possible to translate the rotatable crystal 14 in a linear direction (preferably essentially perpendicular to the fluorescent x-ray flux 26 ) to further remove it from the fluorescent x-ray flux 26 , if necessary. While making EDS measurements, in the preferred embodiment collimator 27 is also removed from its WDS position 29 , to maximize the count rate at the x-ray detector 18 . While making EDS measurements, the x-ray detector 18 is preferably operated in cascade mode.
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The invention provides device which is capable of performing both wave dispersive and energy dispersive x-ray fluorescence spectrometry on a single sample, and utilizing a single radiation detector, such as a PIN diode detector.
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TECHNICAL FIELD
[0001] The present invention relates to oral compositions for suppressing biofilm formation which are useful for prevention of dental caries and, in particular, to an oral composition which uses a novel method for suppressing biofilm formation by utilizing quorum sensing of oral microorganisms.
BACKGROUND ART
[0002] A microorganism adhered to a surface of a material is not singly present but it forms a biofilm together with other microorganisms in the distinctive structure. The biofilm works beneficially for humans as can be seen in the use of immobilized microorganisms, while it is also revealed to be a cause of dental caries and food contamination and thus extensive studies have been conducted in recent years.
[0003] The oral biofilm is formed by 700 or more species of bacteria and 10 8 or more bacteria exist in 1 mg. Streptococci, which take up the majority (20% to 40%) among these bacteria, form a biofilm under the dynamic interbacterial communication mediated by interbacterial active substances on an oral cavity surface. In particular, Streptococcus mutans ( S. mutans ) produces a glutinous exocellular polysaccharide to play a primary role in the pathogenic biofilm formation. The oral biofilm is known to cause dental caries and periodontal diseases and these diseases have been regarded as the microorganism infectious diseases caused by bacteria including S. mutans.
[0004] Conventional prophylactic approaches to dental caries were based on a leading principle that dental caries is suppressed by sterilizing S. mutans or inhibiting enzymes such as glucosyltransferase and the like for prevention of plaque formation. However, in reality, the permeation of antibacterial substances, enzyme inhibitory substances, antibiotics, or the like is prevented by the exocellular polysaccharides covering the biofilm surface in the dental caries and hence in many cases intended effects are not achieved. In addition, the use of antibacterial agents, enzyme inhibitors, antibiotics, or the like, is always next to the risk of resistant bacteria emergence. Although procedures for suppressing a biofilm by mechanical removal such as brushing or scaling have also been used, it is difficult by the current procedures to practice adequate oral care for the elderly who is in need of nursing care, because it is not easy to apply such a mechanical control of oral biofilm to them.
[0005] From these viewpoints, there remains a need for the development of non-traditional methods for removal of biofilm and prevention of tooth decay. For controlling the oral biofilm, it is desirable to practice continuously as a daily routine and it is thus effective to use oral compositions such as food products including gums, etc. or toothpastes.
[0006] The inhibition of quorum sensing is a candidate for a new oral biofilm removal method. Recently, it has been revealed that quorum sensing (QS; cell population density-dependent gene expression regulation system), the molecular mechanism of signal transduction system between bacteria, works on the biofilm formation and pathogenicity expression by S. mutans and the QS in S. mutans is controlled by Competence Stimulating Peptide (CSP), which is an autoinducer. Currently, the various studies on the regulation of biofilm formation and pathogenicity expression targeting such a QS have been attempted in expectation of developing preventive methods for microorganism infectious diseases including oral diseases, which, however, have not yet reached practical use.
[0007] For example, Non Patent Literature 1 discloses that a bacterium called S. salivarius inhibits the biofilm formation by S. mutans and CSP can be regulated by the expression of a specific gene. However, an introduction of microorganisms into oral cavities involves safety issues and gene expression regulation is often accompanied by difficulties. Under such circumstances, development of a safer and simpler method for inhibiting biofilm formation has been expected.
CITATION LIST
Non Patent Literature
[0008] NPL 1: Oral Microbiology And Immunology, 2009 24(2): pp 152-61
SUMMARY OF INVENTION
Technical Problem
[0009] In the conventional methods for suppressing dental caries using antibacterial agents, enzyme inhibitors, antibiotics, or the like, exocellular polysaccharides in the oral biofilm prevent the permeation of antibacterial agents, enzyme inhibitors, antibiotics, or the like, and it is thus difficult to render the intended dental caries suppressive effects. Further, the use of antibacterial agents, enzyme inhibitors, antibiotics, or the like, involves a high risk of resistant bacteria emergence, and hence it is not preferable. For this reason, an object of the present invention is to provide a safer and more effective oral composition for suppressing dental caries by regulating the biofilm formation caused by dental caries causative bacteria instead of controlling the dental caries causative bacteria.
Solution to Problem
[0010] The present inventors have conducted extensive studies and found that a composition which regulates quorum sensing can provide the inhibition of the tooth decay biofilm formation, whereby the present invention has been accomplished.
Advantageous Effects of Invention
[0011] The biofilm formation caused by dental caries causative bacteria is inhibited by the oral compositions of the present invention. These oral compositions can be added to food or drink products, pharmaceutical products, toothpastes, or the like, and then used safely to prevent or treat the tooth decay.
BRIEF DESCRIPTION OF DRAWINGS
[0012] FIG. 1 is a graph showing the biofilm formation amounts of the CSP-induced group and the CSP-uninduced group in each of the control group and in the sample group in Example 1.
[0013] FIG. 2 is a graph showing the rate of change in the biofilm formation amounts when a plant extract is added to each of the CSP-induced group and the CSP-uninduced group in Example 1.
DESCRIPTION OF EMBODIMENTS
[0014] Owing to the studies conducted so far as described in Non Patent Literature 1, quorum sensing (QS) of S. mutans is known to have been regulated by a specific microorganism or gene expression. However, in viewpoint of incorporation into an oral composition such as food products including gums or the like, and toothpastes for controlling dental caries biofilm as a daily routine, a number of problems remain to be unsolved in view of safety issues and convenience issues and thus any of these QS regulatory methods has not yet reached a practical use.
[0015] Under the circumstances, the present inventors conducted extensive studies and consequently found that quorum sensing of S. mutans can be regulated by a specific substance which is safely consumed every day, whereby the inhibition of dental caries biofilm formation by regulating quorum sensing was achieved.
[0016] More specifically, the present invention comprises inhibiting tooth decay biofilm formation associated with quorum sensing using an oral composition containing an extract of a bean.
[0017] According to the oral composition of the present invention, biofilm formation of CSP-dependent S. mutans is inhibited and thus pathogenic bacteria cannot adhere to oral cavities. Thus, suppression of biofilm without relying on mechanical procedures such as brushing or scaling can be achieved.
[0018] Also, unlike the conventional methods for suppressing dental caries which employ antibacterial agents, enzyme inhibitors, antibiotics, or the like, drawbacks of the difficulty to achieve the dental caries suppressive effects, due to the exocellular polysaccharides in the oral biofilm which prevent antibacterial agents, enzyme inhibitors, antibiotics, or the like, from being permeated does not arise.
[0019] Further, since the dental caries can be suppressed without using antibacterial agents, enzyme inhibitors, antibiotics, or the like, the risk of resistant bacteria emergence against antibacterial substances and antibiotics can be suppressed.
[0020] The kind of beans used in the present invention is preferably, but not particularly limited to, an extract extracted from at least one bean selected from black-eyed pea, adzuki bean, scarlet runner bean, white runner bean, black kidney bean and red kidney bean.
[0021] The method for obtaining the extract of a bean as an effective ingredient of the present invention include, but not particularly limited to, grinding of the seeds or fruits (beans) of the above bean plant by suitable grinding means and subsequent extraction such as a solvent extraction to prepare an extract. For the extraction solvent, one of water, lower alcohols such as methanol, ethanol, n-propanol, and n-butanol, and organic solvents such as ether, chloroform, ethyl acetate, acetone, glycerol, and propylene glycol, or a mixture of two or more thereof is used. Among them, a hot water or hydrophilic organic solvent is preferably used. Considering that the extract of the present invention is often used as a food or drink product, it is preferable that, from the aspect of safety, water and ethanol are used in combination to be the extraction solvent. The extraction is carried out preferably with 90% or less of ethanol, further preferably 60% or less of ethanol, further preferably 30% or less of ethanol, and most preferably with hot water.
[0022] For the extraction conditions, the extraction can be carried out at any of a high temperature, room temperature and a low temperature. It is preferred to extract at 50 to 90° C. for about 1 to about 5 hours. The obtained extract may be filtered and, after distilling the extraction solvent, concentrated or freeze-dried under reduced pressure. Also, those obtained by fractionating and purifying these extracts using an organic solvent, column chromatography, or the like, can be used.
[0023] Further, since the oral composition of the present invention is very safe, it can be used every day when contained in oral compositions such as gargles, toothpastes, and mouth sprays; or drink or food products including confectioneries such as chewing gums, candies, tablet sweets, gummy jellies, chocolates, biscuits, and snacks; chilled sweets such as ice creams, sorbets, and ices; beverages, breads, pancakes, dairy products, processed meat products such as hams and sausages; processed fish meat products such as fish pastes and roasted fish pastes; delicatessens, puddings, soups and jams, etc.
[0024] The amount of the extract of a bean to be contained may vary depending on various production conditions, and it is preferably 0.01% by weight or more and 2.0% by weight or less, more preferably 0.01% by weight or more and 1.0% by weight or less with respect to the oral composition.
[0025] Since the present invention uses the extract which has been used for food for a long time, the safety thereof is not a problem even when it is introduced into the oral cavity or body. Also, the extract can be easily consumed when contained in a food product such as chewing gums, toothpastes, or the like, without requiring cumbersome procedures such as regulating gene expression and thus the biofilm can be continuously controlled every day.
EXAMPLES
[0026] Hereinafter, the present invention is described with reference to Examples, but these Examples do not limit the scope of present invention.
Example 1
1. Extract Preparation
[0027] 7 Kinds of beans: black-eyed pea, adzuki bean (Dainagon), adzuki bean (Erimo adzuki bean), scarlet runner bean, white runner bean, black kidney bean and red kidney bean were used as plant samples.
[0028] Each of the plant samples was a commercially purchased product, and 20 g of which was finely ground using a grinder and extracted with 200 ml of water at 70° C. for 2 hours. The obtained extract solution was centrifuged at 3000 rpm for 10 minutes, the supernatant was filtered and the freeze-dried product was subjected to following tests as hot water extracts of each plant.
2. Evaluation of Suppressive Activity on Biofilm Formation
2-1. Biofilm Formation
[0029] S. mutans UA159 strain was anaerobically incubated in 5 ml of Brain Heart Infusion (BHI) broth media at 37° C. for 10 hours, the bacteria collected by the centrifugal separation at 3000 rpm for 10 minutes were treated with phosphate buffered saline (PBS) to prepare OD 550 nm =0.5 and used as a test sample suspension.
[0030] The biofilm formation was carried out by using a 96-well microplate. In each well, 60 μl of each plant hot water extract, 20 μl of CSP, 20 μl of a suspension containing S. mutans to be tested and 100 μl of Todd Hewitt Broth with 0.1% sucrose added were added and the incubation was carried out for 16 hours under the conditions of 37° C. and 5% CO 2 , to form biofilms of the CSP-induced group. The final concentration of CSP was 1 μM and the final concentration of hot water extract of each sample was 1 mg/ml.
[0031] For comparison, the incubation was carried out under the same conditions as above with the exception of not adding CSP, to form the biofilms of the CSP-uninduced group.
[0032] Further, to be used as controls, each of the CSP-induced group and the CSP-uninduced group was incubated under the same conditions as above, except that the sample hot water extracts were not added thereto.
2-2. Biofilm Measurement
[0033] For each of the CSP-induced group and the CSP-uninduced group, the supernatant after the incubation was removed and each well was washed twice with PBS. After washing, a 0.25% safranine solution was added to each well, allowed to stand for 15 minutes, thereafter from which the excess safranine solution was removed and each well was washed twice with PBS. After washing, ethanol was added to each well, safranine stained with shaking for 30 minutes was eluted and an absorbance at 492 nm was measured using a microplate reader to determine an amount of the formed biofilm.
[0034] The results are shown in FIG. 1 and FIG. 2 .
[0035] FIG. 1 shows the biofilm formation amounts of a group (the sample group) to which the incubation was carried out with the addition of the plant extract and the control group, with each group presenting the CSP-induced group and the CSP-uninduced group. FIG. 2 shows the rate of biofilm formation amount of the sample group calculated when the biofilm formation amount of the control group is 100, with each sample group presenting the CSP-induced group and the CSP-uninduced group.
[0036] Referring to FIG. 1 , in the control groups, the biofilm formation amounts were increased in the CSP-induced groups compared to the CSP-uninduced groups. Biofilm formed by quorum sensing due to the CSP as an autoinducer was considered responsible for the increase.
[0037] In the sample groups, the biofilm formation amounts in the CSP-induced groups (black bar) were lower than those of the control groups, whereas the biofilm formation amounts in the CSP-uninduced groups (white bar) were not different from those of the control groups. This is also evident as referred in FIG. 2 , where the CSP-induced groups (black bar) had lower biofilm formation amounts in the sample groups than those in the control groups (below 100%), whereas the CSP-uninduced groups (white bar) had the biofilm formation amounts in the sample groups which were not different from those in the control groups (about 100%). These findings suggested that quorum sensing of S. mutans with the autoinducer CSP was regulated by the plant extracts added to the sample groups, which results in that the amounts of biofilm formed did not increase.
[0038] Further, referring to FIG. 1 , when the hot water extracts of Dainagon adzuki bean, Erimo adzuki bean, scarlet runner bean and red kidney bean were added to the CSP-induced groups and incubated (CSP+ in the sample group), the biofilm formation amounts were lower than those in the groups to which neither CSP nor the plant extract was added (CSP− in the control group).
[0039] Using the adzuki extract prepared in Example 1, a chewing gum, candy and toothpaste were prepared in the routine method. The formulations are shown below. it should be noted that these formulations do not limit the scope of the present invention product.
Example 2
[0040] A chewing gum was prepared in accordance with the following formulation.
[0000]
Gum base
20.0%
by weight
Sugar
55.0
Glucose
15.0
Starch syrup
9.0
Flavor
0.5
Erimo adzuki bean hot water extract (Example 1)
0.5
100.0
Example 3
[0041] A candy was prepared in accordance with the following formulation.
[0000]
Sugar
50.0%
by weight
Starch syrup
34.0
Flavor
0.5
Dainagon adzuki bean hot water extract (Example 1)
0.5
Water
Balance
100.0
Example 4
[0042] A toothpaste was prepared in accordance with the following formulation.
[0000]
Calcium carbonate
50.0%
by weight
Glycerol
20.0
Carbooxymethyl cellulose
2.0
Sodium lauryl sulfate
2.0
Flavor
1.0
Saccharin
0.1
Erimo adzuki bean hot water extract (Example 1)
1.0
Chlorhexidine
0.01
Water
Balance
100.0
[0043] This application claims the priority to the Japanese Patent Application No. 2010-211023, filed on Sep. 21, 2010; and the disclosure of which is hereby incorporated by reference as a part of the present application.
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In the conventional methods for suppressing dental caries using antibacterial agents, enzyme inhibitors or antibiotics, exocellular polysaccharides in oral biofilm prevent the permeation of antibacterial agents, enzyme inhibitors, antibiotics, or the like, and it is thus difficult to render intended suppressive effects on dental caries. Further, use of antibacterial agents or the like involves a high risk of resistant bacteria emergence, and thus it is not preferable. Thus, there remains a need for the development of a safer and more effective method for suppressing dental caries by regulating biofilm formation caused by dental caries causative bacteria instead of controlling the dental caries causative bacteria. A composition which regulates a quorum sensing according to the present invention can provide the inhibition of the tooth decay biofilm formation.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates in general to control systems of an automotive automatic transmission, and more particularly to the control systems of a select-shock suppression type which suppresses or at least minimizes uncomfortable select-shock which would occur when a shift lever of the transmission is shifted from a neutral (N) position to a driving (D) position. More specifically, the present invention is concerned with the select-shock control systems of a type which, for reducing the select-shock, controls a hydraulic pressure applied to a corresponding engaging element of the transmission upon such N→D shifting.
2. Description of the Prior Art
When, under idling of an engine, an accelerator pedal is depressed just after movement of a shift lever from a neutral (N) position to a drive (D) position, racing of the engine tends to occur because of delayed rising of hydraulic pressure as compared with rising of torque and rotation speed of the engine. That is, in such case, engagement of a corresponding clutch can not keep up with the rising of the engine speed, which tends to induce an uncomfortable select-shock.
The above-mentioned undesired phenomenon will be briefly described with reference to the time charts of FIGS. 15A to 15 H of the accompanying drawings. As is understood from the points “P1” of the time charts of FIGS. 15A and 15C (viz., “TH” and “PLDuty”), in the control system of the automatic transmission, a throttle opening degree (viz., depression degree of the accelerator pedal) is monitored, and a line pressure control is so made that the line pressure duty command signal “PLDuty” is instantly shifted to a higher level upon sensing a certain open degree of the throttle valve.
Thus, in the above-mentioned control system, as is understood from the points “P2” of the time chart of FIG. 15E (viz., “PL/C”), after the engine is about to race due to depression of the accelerator pedal, the hydraulic pressure for the low clutch starts to rise and instantly the clutch engaging pressure is raised by “ΔP”. This instant rising of the low clutch engaging hydraulic pressure however interrupts the increasing torque and increasing rotation of the engine, which causes a sudden drop of the engine torque and engine speed as is understood from the points “P3” of the time charts of FIGS. 15F and 15G (viz., “TQ” and “Ne”). As is known, such sudden drop causes the uncomfortable select-shock.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a select-shock control system of an automotive automatic transmission, which is free of the above-mentioned drawback.
According to the present invention, there is provided a select-shock control system of an automatic transmission, which can suppress or at least minimize undesired select-shock which would occur when, under idling of an engine, an acceleration pedal is depressed just after movement of a shift lever from a neutral (N) position to a drive (D) position.
According to the present invention, there is provided a select-shock control system of an automotive automatic transmission in which an engaging element becomes engaged due to application of hydraulic pressure thereto when it is needed to shift the transmission from a neutral condition to a drive condition. The control system comprises a select determination section which determines whether or not the transmission has just been shifted from the neutral condition to the drive condition; an accelerator pedal depression sensing section which senses depression of an accelerator pedal; and a control section which, when the accelerator pedal depression sensing section senses the depression of the accelerator pedal just after determination of the drive condition from the neutral condition by the select determination section, positively induces an oblique rise of the hydraulic pressure from a first lower level which has been kept before depression of the accelerator pedal to a second higher level corresponding to the degree by which the accelerator pedal is depressed.
BRIEF DESCRIPTION OF THE DRAWINGS
Other objects and advantages of the present invention will become apparent from the following description when taken in conjunction with the accompanying drawings, in which:
FIG. 1 is a schematic view of an automatic transmission to which a select-shock control system of the present invention is practically applied;
FIG. 2 is a table showing ON/OFF condition of engaging elements of the transmission with respect to various operative conditions of the transmission;
FIG. 3A is a schematic view of the select-shock control system of the present invention;
FIG. 3B is a schematic view of a control unit employed in the select-shock control system of the invention;
FIG. 4 is a table showing ON/OFF condition of shift solenoids employed in the select-shock control system of the invention;
FIG. 5 is a shift map showing a shift point control executed by the automatic transmission to which the invention is applied;
FIG. 6 is a flowchart showing operation steps carried out upon N→D shifting by a control unit employed in the select-shock control system of the invention;
FIG. 7 is a graph showing a line pressure characteristic and a back pressure characteristic of a low-clutch accumulator, with respect to the throttle opening degree;
FIG. 8 is a graph showing an obliquely changing characteristic of a duty command signal used in the invention with respect to the throttle opening degree;
FIG. 9 is a graph showing an obliquely changing characteristic of the duty command signal with respect to the temperature of a hydraulic fluid;
FIGS. 10A to 10 G are graphs showing time charts of various characteristics which are exhibited when, under idling of an engine, no depression of an acceleration pedal is made just after movement of a shift lever from a neutral (N) position to a drive (D) position;
FIGS. 11A to 11 H are graphs showing time charts of various characteristics which are exhibited when, under idling of the engine, the acceleration pedal is depressed just after movement of the shift lever from the neutral (N) position to the drive (D) position;
FIGS. 12A to 12 H are graphs showing time charts of various characteristics which are exhibited when, under idling of the engine, the acceleration pedal is deeply depressed just after movement of the shift lever from the neutral (N) position to the drive (D) position;
FIGS. 13A to 13 H are graphs showing time charts of various characteristics which are exhibited when, under idling of the engine, the acceleration pedal is depressed during a dish plate stroking period just after movement of the shift lever from the neutral (N) position to the drive (D) position;
FIGS. 14A to 14 G are graphs showing time charts of various characteristics which are exhibited when, under idling of the engine, the acceleration pedal is depressed after completion of engagement of the clutch due to N→D movement of the shift lever; and
FIGS. 15A to 15 H are graphs, obtained by a conventional select-shock control system, showing time charts of various characteristics which are exhibited when, under idling of an engine, an acceleration pedal is depressed just after movement of a shift lever from a neutral (N) position to a drive (D) position.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1 of the drawings, there is shown but schematically an automotive automatic transmission to which a select-shock control system of the invention is practically applied.
In FIG. 1, denoted by reference “IN” is an input shaft, “OUT” is an output shaft, “FPG” is a front planetary gear unit, and “RPG” is a rear planetary gear unit. The front planetary gear unit “FPG” comprises a first sun gear “S1”, a first ring gear “R1”, first pinions “P1” and a first pinion carrier “C1”. The rear planetary gear unit “RPG” comprises a second sun gear “S2”, a second ring gear “R2”, second pinions “P2” and a second pinion carrier “C2”.
To provide the transmission with four speed forward drive and one reverse conditions, a reverse clutch “REV/C”, a high clutch “HIGH/C”, a 2-4 brake “2-4/B”, a low clutch “LOW/C”, a low and reverse brake “L&R/B” and a low one-way clutch “LOW O.W/C” are arranged in the illustrated manner.
The first sun gear “S1” is connected to the input shaft “IN” through a first rotation member “M1” and the reverse clutch “REV/C”, and is connected to a case “K” of the transmission through the first rotation member “M1” and the 2-4 brake “2-4/B”.
The first pinion carrier “C1” is connected to the input shaft “IN” through a second rotation member “M2” and the high clutch “HIGH/C”, and is connected to the case “K” through a third rotation member “M3” and the low and reverse brake “L&R/B”. Furthermore, the first pinion carrier “C1” is connected to the second ring gear “R2” through the third rotation member “M3” and the low clutch “LOW/C”. As shown, the low and reverse brake “L&R/B” and the low one-way clutch “LOW O.W/C” are arranged in parallel with each other.
The first ring gear “R1” is connected to the second pinion carrier “C2” through a fourth rotation member “M4” to which the output shaft “OUT” is directly connected.
The second sun gear “S2” is directly connected to the input shaft “IN”.
The above-mentioned automatic transmission comprises a reduced numbers of parts for achieving a compact and light weight construction. In fact, this transmission has no part which corresponds to a one-way clutch aimed to smooth the “4-3 down shift change” nor part which corresponds to a hydraulic clutch needed for carrying out engine braking due to employment of the one-way clutch.
FIG. 2 is a table which shows ON/OFF condition of engaging elements of the above-mentioned transmission with respect to the operating conditions (viz., four forward drive and one reverse conditions) of the transmission.
As is seen from this table, the first speed “1st” is achieved by engaging the low clutch “LOW/C” and the low and reverse brake “L&R/B” (under engine braking) or engaging the low clutch “LOW/C” and the low one-way clutch “LOW O.W/C” (under acceleration). That is, under this condition, the engine torque is inputted into the second sun gear “S2”, the second ring gear “R2” is fixed and the transmission torque is outputted from the second pinion carrier “C2”.
The second speed “2nd” is achieved by engaging the low clutch “LOW/C” and the 2-4 brake “2-4/B”. That is, under this condition, the engine torque is inputted into the second sun gear “S2”, the first sun gear “S1” is fixed and the transmission torque is outputted from the second pinion carrier “C2”.
The third speed “3rd” is achieved by engaging the high clutch “HIGH/C” and the low clutch “LOW/C”. That is, under this condition, the engine torque is inputted into both the second ring gear “R2” and the second sun gear “S2”, and the torque is outputted from the second pinion carrier “C2”. In this condition, the gear ratio is 1 (one).
The fourth speed “4th” is achieved by engaging the high clutch “HIGH/C” and the 2-4 brake “2-4/B”. Under this condition, the engine torque is inputted into both the first pinion carrier “C1” and the second sun gear “S2”, the first sun gear “S1” is fixed and the transmission torque is outputted from the second pinion carrier “C2”. That is, so-called over drive ratio is established in the transmission.
The reverse is achieved by engaging the reverse clutch “REV/C” and the low and reverse brake “L&R/B”. That is, under this condition, the engine torque is inputted into both the first and second sun gears “S1” and “S2”, the first pinion carrier “C1” is fixed and the transmission torque is outputted from the second pinion carrier “C2”.
The 2-4 brake “2-4/B” is of a multi-plate type similar to a multiple disc clutch.
FIG. 3A is a view showing schematically the select-shock control system of the present invention. That is, shown by this drawing are engaging elements used for achieving an automatic change between the 1st speed and the 4th speed, control valves for hydraulically actuating the engaging elements and an electronic controller for controlling the valves.
As the engaging elements, the low clutch “LOW/C”, the 2-4 brake “2-4/B” and the high clutch “HIGH/C” are shown.
As the control valves, a first shift valve 1 , a second shift valve 2 , a first accumulator control valve 3 , a second accumulator control valve 4 , a low clutch timing valve 5 , a low clutch sequence valve 6 , a 2-4 brake timing valve 7 and a 2-4 brake sequence valve 8 are shown. A low clutch accumulator 9 , a 2-4 brake accumulator 10 and a high clutch accumulator 11 are incorporated with the valves in the illustrated manner.
In accordance with operation of first and second shift solenoids 21 and 22 , the first and second shift valves 1 and 2 switch their fluid passages for achieving the first, second, third or fourth speed.
In accordance with a solenoid pressure “ PSOLA ” produced by a line pressure duty solenoid 23 , the first accumulator control valve 3 reduces a line pressure “ PL ” thereby to regulate an accumulator control pressure “ PACCMA ”. The solenoid pressure “ PSOLA ” produced by the line pressure duty solenoid 23 is led to a pressure modifying valve (not shown) which regulates a modifying pressure which acts as a signal pressure for the line pressure “ PL ” produced by a pressure regulator valve (not shown).
In accordance with a solenoid pressure “ PSOLB ” produced by a 2-4/B duty solenoid 24 , the second accumulator control valve 4 reduces the line pressure “ PL ” thereby to regulate an accumulator control pressure “ PACCMB ”.
The low clutch timing valve 5 is a switching valve which connects a signal pressure passage with a drain side when a low clutch timing solenoid 25 is OFF, and connects the signal pressure passage with a communication side with an aid of hydraulic power when the solenoid 25 is ON.
The low clutch sequence valve 6 controls a back pressure of the low clutch accumulator 9 upon shifting up to or shifting down from the 4th speed.
The 2-4 brake timing valve 7 is a switching valve which connects a signal pressure passage with a drain passage when a 2-4 brake timing solenoid 26 is OFF, and connects the signal pressure passage with a communication side with an aid of hydraulic pressure when the solenoid 26 is ON.
The 2-4 brake sequence valve 8 controls a back pressure of the 2-4 brake accumulator 10 upon shifting up to or shifting down from the 3rd speed.
The low clutch accumulator 9 has a back pressure chamber into which the accumulator control pressure “ PACCMA ” is led through the low clutch sequence valve 6 , whereby engagement/releasement action of the low clutch “LOW/C” is smoothly carried out.
The 2-4 brake accumulator 10 has a back pressure chamber into which the accumulator control pressure “ PACCMB ” is led through the 2-4 brake sequence valve 8 , whereby engagement/releasement action of the 2-4 brake “2-4/B” is smoothly carried out.
The high clutch accumulator 11 has a back pressure chamber into which the accumulator control pressure “ PACCMA ” is directly led, whereby engagement/releasement of the high clutch “HIGH/C” is smoothly carried out.
In FIG. 3A, denoted by numeral 32 is a fluid passage for the low clutch pressure and 33 is a fluid passage for the low clutch accumulator back pressure.
The electric controller includes a control unit 20 which controls the above-mentioned six solenoids 21 , 22 , 23 , 24 , 25 and 26 .
Information signals from a throttle angle sensor 27 , a vehicle speed sensor 28 , a turbine speed sensor 29 , an oil temperature sensor 30 and other sensors and switches 31 are fed to the control unit 20 .
As is seen from FIG. 3B, the control unit 20 is a computer which comprises a central processing unit (CPU), a random access memory (RAM), a read only memory (ROM), an input interface “I-PORT” and an output interface “O-PORT”. Instruction signals from the control unit 20 are led to the six solenoids 21 , 22 , 23 , 24 , 25 and 26 and an engine controller.
Referring back to FIG. 3A, the control of the back pressure of the low clutch accumulator 9 upon N→D shifting is carried out as follows. That is, upon sensing a switch signal from an inhibitor switch, the control unit 20 judges that the shift lever has been shifted to the drive (D) range from the neutral (N) range. Upon this, the control unit 20 issues a duty command signal “PLDuty” to the line pressure duty solenoid 23 to control the accumulator control pressure “ PACCMA ” led to the back pressure chamber of the low clutch accumulator 9 .
The automatic shift change executed in the transmission between the 1st speed and the 4th speed is carried out following the shift map of FIG. 5 . That is, the automatic shifting in the transmission is carried out with respect to a vehicle speed, a throttle valve position and a predetermined upshift/downshift characteristic of the transmission. When one of the shift characteristic lines is crossed, upshift or downshift command signal is issued from the control unit 20 to make the first and second shift solenoids 21 and 22 ON or OFF in such a manner as is shown in the table of FIG. 5 . That is, for example, for achieving a shifting to the 1st speed, both the first and second shift valves 21 and 22 are made ON, that is, energized.
In the following, operation of the select-shock control system of the present invention will be described with reference to the flowchart of FIG. 6 which shows operation steps carried out by the control unit 20 upon the N→D shifting.
At step 70 , upon receiving a switch signal from an inhibitor switch, a determination is so made that a shift lever of the transmission has been shifted to D-position from N-position. From this step 70 , the select-shock control starts.
At step 71 , a duty command signal “PLDuty” for a normal select control (viz., idle select control) is issued to the line pressure duty solenoid 23 . That is, upon determination of the N→D shifting, a normal select control signal is outputted for a first predetermined time “t1”, which, as is shown, consists of a first higher duty ratio flat part and a second lower duty ratio flat part. This normal select control is executed when the engine speed “Ne” is equal to or smaller than 1600 RPM, the throttle opening degree “TH” is equal to or smaller than {fraction (1/16)} of full opening and the vehicle speed “VSP” is equal to or smaller than 7 KM/h.
At step 72 , judgment is carried out as to whether the existing throttle opening degree “TH” is greater than a predetermined degree “THa” or not. The predetermined degree “THa” is set for example at {fraction (1/16)} of full opening. If NO, that is, when the existing throttle opening degree “TH” is smaller than {fraction (1/16)} of full opening, the operation flow goes to step 73 . At this step, judgment is carried out as to whether a real time “T” from the time on which the N→D shifting was determined is greater than the first predetermined time “t1” or not. If YES, the operation flow goes to step 74 and the normal select control is ended. If desired, ending of this normal select control may be made when a gear ratio becomes to a predetermined degree.
If YES at step 72 , the operation flow goes to step 75 . At this step, judgment is carried out as to whether the existing throttle opening degree “TH” is smaller than an arbitrary degree “TH0” or not. For example, the arbitrary degree is ⅞ of full throttle opening. If NO, that is, when the existing throttle opening degree “TH” is greater than the arbitrary degree, the operation flow goes to step 76 . At this step, a so-called “immediate depression responsive control” which will be described in detail at step 82 is inhibited. Then, the operation flow goes to step 77 . At this step, a duty command signal “PLDuty” is issued to the line pressure duty solenoid 23 , which increases with increase of the throttle opening degree “TH” under a normal line pressure control.
If YES at step 75 , that is, when the existing throttle opening degree “TH” is smaller than the arbitrary degree “TH0”, that is, when the inequality “THa<TH<TH0” is satisfied, the operation flow goes to step 78 . At this step, the immediate depression responsive control starts. Then, the operation flow goes to step 79 . At this step, judgment is carried out as to whether the real time “T” from the determination of the N→D shifting is greater than a second predetermined time “t2” (viz., dish plate stroke time) or not. Thus, the normal select control is kept until this time “t2”.
If YES, that is, when the real time “T” is greater than the second predetermined time “t2”, the operation flow goes to step 80 . At this step, judgment is carried out as to whether the real time “T” is smaller than a third predetermined time “t3” (viz., clutch engagement completion time) or not. If desired, in place of this judgment, the clutch engagement completion may be judged from the gear ratio between input and output shafts.
If NO at step 80 , the operation flow goes to step 81 . At this step, the after-mentioned immediate depression responsive control is ended.
If YES at step 80 , that is, when the inequality “t2<T≦t3” is satisfied, the operation flow goes to step 82 . At this step, the immediate depression responsive control is substantially executed. That is, upon satisfaction of the inequality, a duty oblique raising control is executed. That is, upon the satisfaction, a gradually raising duty ratio part “DOR” appears in the duty command signal “PLDuty”. Due to appearance of this part “DOR”, the back pressure of the low-clutch accumulator 9 (see FIG. 3A) is increased by “ΔP” (see FIG. 7) from a level kept prior to the depression of the accelerator pedal to a level corresponding to the depression degree of the accelerator pedal.
The gradually raising duty ratio part “DOR” has a gradient of “θ”.
The gradient “θ” may be a fixed value, or gradually decreased with increase of the throttle opening degree as is seen from FIG. 8, or gradually decreased with increase of the temperature of an operating fluid as is seen from FIG. 9 . Furthermore, if desired, the gradient “θ” may be changed in accordance with a change of an operating factor or factors, such as a torque capacity “Qa” and/or a torque converter slip degree “(Ne—Nt)”, which have an influence on a raising responsibility of the engaging torque for the low clutch “LOW/C”.
After step 82 , the operation flow goes to step 83 and step 84 . At step 83 , expiration of the first predetermined time “t1” is detected and at step 84 , the immediate depression responsive control is ended.
NORMAL SELECT CONTROL
FIGS. 10A to 10 G are graphs showing time charts of various characteristics of the normal select control, which are exhibited when, under idling of an associated engine, no depression of the acceleration pedal is made just after movement of the shift lever from the neutral (N) position to the drive (D) position.
This normal select control is carried out while executing the steps 70 , 71 , 72 , 73 and 74 of the flowchart of FIG. 6 .
That is, upon determination of the N→D shifting, the duty command signal “PLDuty” is issued for the first predetermined time “t1”, which consists of the first higher duty ratio flat part and the second lower duty ratio flat part. In response to this signal, the accumulator control pressure “ PACCMA ” is temporarily raised at the time of the N→D determination and thereafter lowered to a constant level, and the low clutch pressure “ PL/C ” is raised at the time of the N→D determination and thereafter gently raised. Upon raising of the low clutch pressure “ PL/C ”, the engagement movement of the low clutch “LOW/C” starts.
Accordingly, in the transitional stage for the low clutch engagement, the engine torque “TQ” shows a gentle rising and upon completion of the engagement, shows a slight drop. In the transition stage for the low clutch engagement, the engine speed “Ne” shows a very small reduction, and the turbine speed “ NT ” is gradually lowered to zero.
As is understood from the above description, when the accelerator pedal is not depressed just after the N→D shifting, increase of the engine speed “Ne” and marked increase of the engine torque “TQ” do not occur in the transitional stage for the low clutch engagement. Thus, by only controlling the initial increase of the low clutch pressure “ PL/C ”, the engagement of the low clutch “LOW/C” is smoothly achieved without select-shock.
IMMEDIATE DEPRESSION RESPONSIVE CONTROL
FIGS. 11A to 11 H are graphs showing time charts of various characteristics of the immediate depression responsive control, which are exhibited when, under idling of the engine, the accelerator pedal is depressed just after movement of the shift lever to the drive (D) position from the neutral (N) position.
This immediate depression responsive control is carried out while executing the steps 70 , 71 , 72 , 75 , 78 , 79 , 80 , 82 , 83 and 84 of the flowchart of FIG. 6 .
That is, upon determination of the N→D shifting, the duty command signal “PLDuty” for the normal select control is issued for a time longer than the second predetermined time “t2” which corresponds to the disc plate stroke time. Upon sensing the depression of the accelerator pedal, the duty command signal “PLDuty” shows the gradually raising duty ratio part “DOR” which has a duty height “ΔP” corresponding to a duty ratio “P1” corresponding to the depression degree of the accelerator pedal, and upon sensing expiration of the first predetermined time “t1”, the duty height of the duty command signal “PLDuty” is increased to a duty ratio “P 2 ” for the normal line pressure control. In response to this signal, the accumulator control pressure “ PACCMA ” is temporarily raised at the time of the N→D determination and thereafter lowered, and after depression of the accelerator pedal, the accumulator control pressure “ PACCMA ” is gradually raised. In response to the signal, the low clutch pressure “ PL/C ” is raised at the time of the N→D determination and thereafter gently raised.
Accordingly, in the transitional stage for the low clutch engagement, the engine torque “TQ” shows a gentle rising and upon completion of the engagement, shows a drop. However, as compared with the torque drop “P3” appearing in the conventional shock control system (see FIG. 15 F), the drop in the invention is quite small. Furthermore, as is seen from FIGS. 11G and 11H, the drop “ DN e” of the engine speed “Ne” and that “ DNT ” of the turbine speed “ NT ” are quite small as compared with those of the conventional system (see FIGS. 15 G and 15 H).
As is understood from the above description, when, under idling of the engine, the acceleration pedal is depressed just after N→D movement of the shift lever, the engine torque “TQ” and is engine speed “Ne” which have a high responsibility to the pedal depression are gradually lowered by the gradual or slipping engagement of the low clutch “LOW/C”. Thus, undesired select-shock can be minimized.
If the gradient “θ” of the gradually raising duty ratio part “DOR” (see FIG. 11C) is varied in accordance with the throttle opening degree and the temperature of the hydraulic fluid as is seen from the graphs of FIGS. 8 and 9, the select-shock minimization is stably carried out irrespective of depression degree of the accelerator pedal and of the operating condition of the transmission.
IMMEDIATE & DEEP DEPRESSION RESPONSIVE CONTROL
FIGS. 12A to 12 H are graphs showing time charts of various characteristics of an immediate and deep depression responsive control, which are exhibited when, under idling of the engine, the accelerator pedal is deeply depressed just after movement of the shift lever to the drive (D) position from the neutral (N) position.
This immediate and deep depression responsive control is carried out while executing the steps 70 , 71 , 72 , 75 , 76 and 77 .
That is, upon sensing the deep depression of the accelerator pedal just after the N→D shifting, the operation flow (see FIG. 6) goes to step 76 to inhibit the above-mentioned immediate depression responsive control and goes to step 77 . That is, in this case, normal line pressure control is carried out to effect a rapid rising of the low clutch pressure “ PL/C ” after the deep pedal depression. With this control, engaging speed of the low clutch “LOW/C” is increased.
DEPRESSION RESPONSIVE CONTROL UNDER DISH PLATE STROKE
FIGS. 13A to 13 H are graphs showing time charts of various characteristics of a depression responsive control under dish plate stroke, which are exhibited when, under idling or the engine, the accelerator pedal is depressed during stroke of dish plates of the low clutch “LOW/C” after movement of the shift lever to the drive (D) position from the neutral (N) position.
The “depression responsive control under dish plate stroke” is carried out while executing the steps 70 , 71 , 72 , 75 , 78 and 79 of the flowchart of FIG. 6 .
That is, upon sensing depression of the accelerator pedal during the stroke of the dish plates just after the N→D shifting, the immediate depression responsive control is postponed until expiration of the second predetermined time “t2”, that is, until termination of the dish plate stroke. In other words, once the dish plate stroke terminates, the immediate depression responsive control starts. As will be seen from the partial curves shown by dotted lines, if the immediate depression responsive control is carried out just after depression of the accelerator pedal, the low clutch pressure “ PL/C ” would show a rapid rising just after termination of the dish plate stroke, which tends to produce a select-shock.
SLOW DEPRESSION RESPONSIVE CONTROL
FIGS. 14A to 14 G are graphs showing time charts of various characteristics of a slow depression responsive control, which are exhibited when, under idling of the engine, the accelerator pedal is depressed after engagement of the low clutch “LOW/C” due to the N→shifting.
This slow depression responsive control is carried out while executing the steps 70 , 71 , 72 , 75 , 78 , 79 , 80 and 81 of the flowchart of FIG. 6 .
That is, upon sensing such depression of the accelerator pedal, the immediate depression responsive control is not carried out even after engagement of the low clutch “LOW/C”. In other words, when the depression of the accelerator pedal is slowly made, the immediate depression responsive control does not occur. As will be seen the partial curves shown by dotted lines, if the immediate depression responsive control is carried out just after engagement of the low clutch “LOW/C”, undesired slipping of the low clutch “LOW/C” tends to occur.
It is to be understood that, although the invention has been described with specific reference to a particular embodiment thereof, it is not to be so limited since changes and alternations therein may be made within the full intended scope of this invention as defined by the appended claims. That is, the concept of the invention can be used in case wherein the shift lever is moved from N-position to R(reverse)-position or from N-position to 1 or 2 fixed position.
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A select-shock control system of an automotive automatic transmission is shown. The transmission has an engaging element which becomes engaged due to application of hydraulic pressure thereto when it is needed to shift the transmission from a neutral condition to a drive condition. The control system comprises a select determination section which determines whether or not the transmission should be actually shifted from the neutral condition to the drive condition; an accelerator pedal depression sensing section which senses depression of an accelerator pedal; and a control section which, when the accelerator pedal depression sensing section senses the depression of the accelerator pedal just after determination of the drive condition from the neutral condition by the select determination section, raises obliquely the hydraulic pressure from a first lower level which was kept before depression of the accelerator pedal to a second higher level corresponding to the degree by which the accelerator pedal has just been depressed.
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BACKGROUND OF THE INVENTION
The present invention generally relates to so-called high electron mobility transistor (HEMT) devices and more particularly to a HEMT device having a heterojunction between an indium gallium arsenide (InGaAs) active layer and an n-type aluminium indium arsenide (AlInAs) electron supply layer and a manufacturing method thereof.
A direct-coupled FET logic (DCFL) device comprises an enhancement-mode field effect transistor (FET) and a depletion-mode FET and is characterized by low power consumption. Thus, the device is suited for constructing a high speed integrated circuit having a large integration density. In relation to the DCFL device, techniques have been studied intensively for manufacturing an inverter circuit for the DCFL device by employing a compound semiconductor device so as to improve the operational speed of the device further.
Conventionally, there is a known DCFL device comprising an enhancement-mode FET and a depletion mode FET both formed on a common semi-insulating gallium arsenide (GaAs) substrate as is disclosed in the U.S. Pat. Nos. 4,635,343 and 4,733,283, in which the assignee is the same assignee of the present invention. In this device, a two-dimensional electron gas is formed at a heterojunction interface between an undoped GaAs layer on the GaAs substrate and an n-type AlGaAs layer making a direct contact therewith. The two-dimensional electron gas is formed at an upper portion of the undoped GaAs layer and the electrons therein can move without experiencing scattering by the dopants. In other words, the electron mobility in the two-dimensional electron gas is increased and the operational speed of the device is significantly improved.
When manufacturing such a device, a layered body comprising the foregoing GaAs substrate, the undoped GaAs layer, and the n-type AlGaAs layer as well as an n-type GaAs layer provided on the n-type AlGaAS layer, a second n-type AlGaAs layer further provided on the n-type GaAs substrate, and a cap layer of n-type GaAs further provided on the n-type AlGaAs layer, is prepared. Further, a source electrode and a drain electrode are provided on the cap layer according to a predetermined pattern. Next, the layered body is applied with a photoresist and after a suitable patterning for exposing a part of the structure corresponding to a gate electrode of the enhancement-mode FET, the cap layer is removed by a dry etching procedure using a chloride etching gas. When the second n-type AlGaAs layer is exposed, the etching is automatically stopped because of the reduced etching rate in the AlGaAs layer. Note that the etching rate of AlGaAs by chloride gas is smaller by a factor of 200 than the etching rate of GaAs. Then, the n-type AlGaAs layer is removed by a wet etching and after a suitable photolithographic process for exposing another part of the structure corresponding to a gate of the depletion-mode FET, the first n-type GaAs layer corresponding to the gate of the enhancement-mode FET and the cap layer of GaAs corresponding to the gate of the depletion-mode FET are removed by again applying the dry etching using the chloride etching gas. This second dry etching also stops automatically when the n-type AlGaAs layer immediately above the undoped GaAs layer is exposed and when the second n-type AlGaAs layer is exposed. Then the gate electrode for the enhancement-mode FET and the depletion-mode FET are provided and an invertor circuit forming the DCFL is obtained. According to this procedure, the etching is stopped exactly at a desired depth as a result of use of the undoped or doped AlGaAs layer, and the enhancement-mode FET and the depletion-mode FET are formed with an exactly controlled threshold voltage.
Meanwhile, it is known that the operational speed of the HEMT device would be further improved if one could use a heterojunction of n-type aluminium indium arsenide (AlInAs) and undoped indium gallium arsenide (InGaAs). By using an InGaAs layer as the layer for supporting the two-dimensional electron gas, one can increase the electron mobility under a low electrical field and can obtain a high electron velocity under a high electrical field, too. Further, the electron density in the two-dimensional electron gas is increased because of the increased potential barrier established at the heterojunction. Furthermore, the decrease of the electron mobility by electron transfer to the low mobility band is avoided because of characteristic band structure of InGaAs which exhibits a large energy difference between the L valley and the valley. Additionally, there is a further advantage such that InAlAs is substantially free from unwanted deep donors.
Unfortunately, there is no known dry etching technique effectively applicable to the system, such as AlInAs or InGaAs involving indium (In), for providing the gate structure of a HEMT device and thus the manufacturing of the HEMT device using this promising material combination has been extremely difficult even in the case that the device is a simple FET. The device such as inverter is out of question. For example, the dry etching using carbon dichloro-difluoride (CCl 2 F 2 ) as the etching gas is virtually ineffective on a material such as InGaAs containing indium. It is believed that the reason for this is the significantly reduced equilibrium vapor pressure of indium trichloride (InCl 3 ) which is formed as a product of the etching reaction (see S.C. McNevin, J. Vac. Sci. Technol., B4 (5) 1986, pp. 1216).
Because of the foregoing reasons, there is so far no report announcing success in constructing a HEMT integrated circuit device in which a heterojunction of n-type AlInAs and InGaAs is used.
SUMMARY OF THE INVENTION
Accordingly, it is a general object of the present invention to provide a novel and useful HEMT device and a manufacturing method thereof wherein the aforementioned problems are eliminated.
Another and more specific object of the present invention is to provide a high speed HEMT device by forming a heterojunction of n-type AlInAs and undoped InGaAs therein.
Another object of the present invention is to provide a high speed HEMT device having a heterojunction of n-type AlInAs and undoped InGaAs wherein the device has a structure which allows easy formation of a gate structure by etching.
Another object of the present invention is to provide a high speed HEMT device having a heterojunction of n-type AlInAs and undoped InGaAs and a method wherein the uniformity of the threshold voltage of FET or FETs formed therein is improved.
Another object of the present invention is to provide a method of manufacturing a HEMT device having a heterojunction of n-type AlInAs and undoped InGaAs wherein an etching treatment for providing a gate structure is performed uniformly and reliably.
Another object of the present invention is to provide a HEMT device comprising a semi-insulating indium phosphide (InP) substrate, a non-doped InGaAs active layer provided on the InP substrate, an n-type InAlAs layer for supplying electrons provided on the InGaAs active layer, a cap layer of n-type gallium arsenide antimonide (GaAsSb) provided on the n-type InAlAs layer, a recessed structure provided on a part of the cap layer for exposing the n-type InAlAs layer, a gate electrode provided on the cap layer in correspondence to the recessed structure so as to make a Schottky contact with the n-type InAlAs layer, and a pair of ohmic electrodes provided on the cap layer at both sides of the gate electrode for making an ohmic contact of each electrode with the cap layer. According to the present invention, the cap layer is free from In and thus can be easily etched by conventional dry etching process using a chloride etching gas such as CCl 2 F 2 . As the n-type InAlAs layer is substantially insensitive to the dry etching, the thus-obtained HEMT device has a gate structure which is formed with excellent precision and uniformity similarly to the conventional HEMT device using the heterojunction of n-type AlGaAs and GaAs. Further, as a result of the present invention, a large scale integrated circuit of HEMT devices using the heterojunction of the n-type InAlAs layer and the InGaAs active layer can be formed easily and with reliability.
Other objects and further features of the present invention will become apparent from the following detailed description when read in conjunction with attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagram showing a first embodiment of the HEMT device of the present invention;
FIG. 2 is a diagram showing a band structure of the device of FIG. 1; and
FIGS. 3 through 8 are diagrams showing various steps for manufacturing the HEMT device according to an embodiment of the present invention.
DETAILED DESCRIPTION
FIG. 1 shows a first embodiment of the HEMT device of the present invention. In this embodiment, the device forms an enhancement-mode FET. Referring to the drawing, the device comprises a semi-insulating InP substrate 11 on which an active layer 12 of undoped InGaAs is provided. On the active layer 12, a doped layer 13 is provided such that there is formed a heterojunction 14 at the interface between the layer 12 and the layer 13. The thickness of the layer 13 is chosen such that a desired threshold voltage is obtained for the FET realized by the present device. Further, there is provided a cap layer 15 of GaAsSb on the doped layer 13 except for a recessed gate structure 15a wherein a gate electrode 16 of a metal forming a Schottky contact with InAlAs is provided in contact with the doped layer 13. Further, ohmic electrodes 17 and 18 forming an ohmic contact with GaAsSb are provided on the cap layer 15 as source and drain electrodes respectively. The compositions of the active layer 12, the doped layer 13, and the cap layer 15 are chosen so as to achieve excellent lattice matching of the layers with respect to the substrate and with respect to each other. In one example, the composition of the active layer 12 is set to about In 0 .53 Ga 0 .47 As, the composition of the doped layer is set to about In 0 .52 Al 0 .48 As, and the composition of the cap layer 15 is set to about GaAs 0 .51 Sb 0 .49.
In operation, electrons are injected into the two dimensional electron gas, shown by a broken line at the interface 14, from the ohmic electrode 17 via the cap layer 15 by applying an electrical voltage across the electrodes 17 and 18 and the injected electrons are transported through the active layer 13 along the heterojunction 14 in a form of the two-dimensional electron gas under control of a gate voltage applied to the gate electrode 16 which modifies the band structure in the vicinity of the heterojunction 14 and hence the electron density in the two-dimensional electron gas. The electrons passed through the active layer under the gate electrode 16 are then recovered by the other ohmic electrode 18 after passing through the cap layer 15 in a reverse direction. Note that the operational characteristic, particularly the threshold voltage V th , is determined as a function of the distance between the gate electrode 16 and the active layer 12 or, as determined by the thickness of the doped layer 13.
Because of in the difference of band structure between that of InGaAs forming the active layer 12 and that of the n-type InAlAs forming the doped layer 13, there is formed a large discontinuity in the conduction band edge at the heterojunction 14 which facilitates the formation of the two-dimensional electron gas. In other words, the electron density in the two-dimensional electron gas is increased because of the large potential barrier and associated deep potential valley appearing at the heterojunction. The advantageous use of the heterojunction between the n-type InAlAs doped layer and the undoped InGaAs active layer is already summarized and will not be repeated.
In the present invention, as a result of the use of GaAsSb for the cap layer 15, the dry etching process used to form the recessed gate structure 15a in the cap layer 15 is performed easily with high precision and high reproducibility as the etching is automatically stopped when it reaches the InAlAs doped layer 13. It was found, further, that there is formed only a limited potential barrier at the junction between the GaAsSb cap layer 15 and the underlying doped layer 13 and the injection of electrons through the ohmic electrode 17 or 18 is performed without difficulty.
FIG. 2 shows a band structure of the device of FIG. 1 taken along an X--X' line of FIG. 1. In the drawing, the region I corresponds to the ohmic electrode 17 or 18, the region II corresponds to the cap layer 15, the region III corresponds to the doped layer 13 and the region IV corresponds to the active layer 12. Further, the Fermi level is represented as E F , and the band gaps the cap layer 15, the doped layer 13 and in the active layer 12 are represented by E g1 , E G2 and E G3 , respectively. In the HEMT device of FIG. 1 in which the layers 12, 13 and 15 have the foregoing compositions, the band gap assumes the following values.
E G1 =0.8[eV]
E G2 =1.1[eV]
E G3 =0.6[eV]
Further, there is formed a discontinuity E H2 in the conduction band at the interface 14 between the active layer 12 and the doped layer 13 as is expected, and in which the band discontinuity E H2 takes a value of 0.5 eV. This value is significantly larger than the that of the conventional n-type AlGaAs/GaAs heterojunction which assumes a value of 0.3 eV. Thus, the electron density in the two-dimensional electron gas formed at the interface 14 is increased substantially.
Note that there is also formed a discontinuity in the conduction band edge at the interface between the cap layer 15 and the doped layer 13 having a magnitude of E H1 . This discontinuity, however, is very small and assumes a value of about 0.05 eV. Thus, although there may be a potential barrier at the interface between the cap layer 15 and the doped layer 13, the electrons can pass substantially freely through this interface and the operation of the device is facilitated. In other words, the combination of the cap layer 15 of GaAsSb and the doped layer 13 of InAlAs not only enables easy and precise etching of the gate structure using the known etching gas but also reduces the ohmic contact of the ohmic electrodes.
Next, a second embodiment of the HEMT device of the present invention will be described together with a manufacturing process with reference to FIGS. 3 through 8. The HEMT device according to the second embodiment has a structure called an E/D type wherein both an enhancement-mode FET and a depletion-mode FET are formed on a common substrate.
Referring to FIG. 3, a structure comprising a semi-insulating substrate 21 of InP, an active layer 22 of intrinsic type InGaAs having a composition of In 0 .53 Ga 0 .47 As, an doped layer 23 of n-type InAlAs having a composition of In 0 .52 As 0 .48 As, and a cap layer 24 which in turn comprises three distinct layers to be described, is formed by growing the respective materials consecutively by molecular beam epitaxy (MBE) or metal-organic chemical vapor deposition (MOCVD). Note that the doped layer 23 is grown to a thickness which provides a desired threshold voltage for the enhancement-mode FET formed in the HEMT device. The cap layer 24 is provided in order to reduce the resistance between ohmic electrodes provided thereon and the doped layer 23 thereunder similarly to the device of FIG. 1 and further for establishing a desired threshold voltage for the depletion-mode FET formed in the device. The composition of the layers 22-24 is determined so that there is established excellent lattice matching between these layers including the substrate 21.
In the HEMT device of the present invention, the cap layer 24 comprises a GaAsSb layer 24A doped to the n-type and having a composition of about GaAs 0 .51 Sb 0 .49, an InAlAs layer 24B doped to the n-type and having a composition of about In 0 .52 Al 0 .48 As, with a thickness determined so as to provide said desired threshold voltage of the depletion-mode FET, and another GaAsSb layer 24C doped similarly to the n-type and having a composition of about GaAs 0 .51 Sb 0 .49. The thickness of the InAlAs layer 24B is chosen to about 20-30Å. This layer 24B containing In, also acts as an etching layer similarly to the prior art device disclosed in the foregoing U.S. Pat. Nos. 4,635,343 and 4,733,283.
In this structure, there is formed a heterojunction at an interface between the active layer 22 and the doped layer 23, and a two dimensional electron gas is formed in the uppermost part 22a of the active layer 22 as illustrated by a broken line. In the drawing, a part of the structure thus formed in which the enhancement-mode FET is to be formed is designated as E and a part of the structure in which the depletion-mode FET is to be formed is designated as D.
Next, a silicon oxide (SiO 2 ) layer 25 is deposited on the structure FIG. 3 for device separation and windows 25a are opened through the layer 25 in correspondence ohmic electrodes to be described by a photolithographic process using a suitably patterned photoresist (not shown). Then, while leaving the photoresist on the silicon oxide layer 25, a metal layer for forming the ohmic electrodes is deposited on the cap layer 24 through the windows 25a by magnetron sputtering. Further, the photoresist on the silicon oxide layer 25 is dissolved and the metal layer filling the window 25a is lifted off so as to form a substantially flush surface with the silicon oxide layer 25. Thus, an ohmic electrode 26 is formed in correspondence to each window 25a defined in the silicon oxide layer 25 as illustrated in FIG. 4.
Next, as shown in FIG. 5, a photoresist 27 is applied on the structure of FIG. 4 and is subsequently patterned photolithographically so as to form a window 27a exposing a part of the silicon oxide layer 25 in correspondence to a gate of the enhancement-mode FET to be formed in the device. Then, the silicon oxide layer 25 is selectively removed in correspondence to the window 27a by hydrofluoric acid (HF). Subsequently, a reactive ion etching (RIE) process step is applied using an etching gas of CCl 2 F 2 and helium. As a result, the GaAsSb layer 24C in the cap layer 24 are similarly removed. Note that the layer 24C is free from In and thus easily removed by RIE. This etching process automatically stops at the InAlAs layer 24B containing In. Note that the etching rate for GaAsSb is faster by a factor of about 50 than that for InAlAs when the foregoing etching gas is used. Further, a wet etching process using an aqueous solution of hydrogen peroxide (H 2 O 2 ) and sulfuric acid (H 2 SO 4 ) is applied so as to remove the InAlAs layer 24B exposed in the window 27a and a recessed gate structure 25E shown in FIG. 5 is obtained. Note that the GaAsSb layer 24A is exposed at the bottom of the recessed gate structure 25E.
Next, as shown in FIG. 6 another window 27b is formed in the photoresist 27 by a photolithographic process so as to expose a part of the silicon oxide layer 25 in correspondence to a gate of the depletion-mode FET to be formed in the device. By applying the RIE process using and the GaAsSb layer 24C exposed by the window 27b is removed similarly to the foregoing etching process until the InAlAs layer 24B is exposed. Thereby a recessed gate structure 25D shown in FIG. 6 is obtained. At the same time, the GaAsSb layer 24A exposed at the bottom of the recessed gate structure 25E is also removed. The layer 24A is also free from In and thus the RIE process is applied effectively. The etching is continued until the doped layer 23 is exposed. Thus, a structure shown in FIG. 6 is obtained.
Next, a layer of a metal for forming a Schottky contact with InAlAs, is deposited on the structure of FIG. 6 by magnetron sputtering while leaving the photoresist 27 as it is. After the deposition, the photoresist is removed and the metal for filling the recessed gate structures 25E and 25D, is applied by a lift-off patterning process step. As a result, the structure of a gate electrode 28a of the enhancement-mode FET having a flush surface with the silicon oxide layer 25 and a gate electrode 28b of the depletion-mode FET projecting above the silicon oxide layer 25 as shown in FIG. 7 is obtained.
Next, an interlayer insulator 29 is provided on the structure of FIG. 7 by a chemical vapor deposition (CVD) or the like, and a metal interconnection 30 is provided so as to make an electrical contact with the electrodes 26, 28a and 28b via respective contact holes which in turn are provided in correspondence to the electrodes 26, 28a and 28b by known photolithographic patterning. Thus, the HEMT device shown in FIG. 8 is completed.
It should be noted that the selective etching process using the patterned photoresist 27 is also applicable to manufacture the device of FIG. 1. In this case, the layer 24B is not provided and the recessed gate structure 15a is formed by a single etching process step.
In the device of FIG. 8, the gate electrode 28a in contact with the doped layer 23 acts as the gate electrode of the enhancement mode FET having a source and a drain electrodes 26 at both sides thereof while the gate electrode 28b which is separated from the doped layer 23 by the cap layer 24 layers 24A and 24B acts as the gate electrode of the depletion mode FET, having source and drain electrodes, at the opposite sides. Further, the ohmic electrode 26 located between the gate electrode 28a and the gate electrode 28b is common and the device forms an inverter circuit.
In this device, the etching step for forming the recessed gate structures 25E and 25D is stopped exactly at the doped layer 23 and at the InAlAs layer 24B, each acting as an effective etching stop layer, and the distance between the active layer 22 and the gate electrode 28a or the distance between the active layer 22 and the gate electrode 28b is controlled precisely through the epitaxial growth. In other words, the threshold voltage of each of the enhancement-mode FET E and the depletion-mode FET D is controlled exactly at the time of manufacturing of the device.
Further, the present invention is not limited to these embodiments but various variations and modifications may be made without departing from the scope of the present invention.
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A semiconductor device having a heterojunction and utilizing a two-dimensional electron gas formed at said the heterojunction comprises a substrate of a semi-insulating material, a first semiconductor layer of undoped indium gallium arsenide formed on the substrate, a second semiconductor layer of n-type indium aluminium arsenide formed on the first semiconductor layer and defining the heterojunction between the first semiconductor layer and the second semiconductor layer, the second semiconductor layer including an exposed region defining an exposed top surface, a third semiconductor layer of n-type gallium arsenide antimonide formed on the second semiconductor layer and having a window defined therein so as to expose the top surface of the exposed top surface region, a gate electrode formed in self-alignment with the window and in contact with the exposed top surface region of the second semiconductor layer, and ohmic electrodes formed on the cap layer in ohmic contact therewith.
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TECHNICAL FIELD
[0001] This invention relates generally to bulk shipping and storage containers. More particularly, the invention relates to a bulk container made of reinforced cross-laminated corrugated paperboard. In a preferred embodiment the container has interlocking full bottom flaps and is especially adapted for containing fluid products.
BACKGROUND ART
[0002] In the bulk handling of materials, and especially fluid or flowable materials such as liquids, powders and granules, containers of 20 to 80 gallon capacity are commonly used to transport and store the material. These containers should be capable of withstanding the weight of the contents and of being stacked on top of one another. They should also be capable of withstanding the rough handling to which they may be subjected, and be capable of being handled with mechanized equipment.
[0003] A variety of containers have been developed in the prior art in an effort to meet these criteria, including drums made of metal or fibre, plywood bins, and corrugated paperboard containers. While plywood bins and drums made out of metal or fibre possess the requisite strength and durability, they are expensive to manufacture, store and ship.
[0004] Corrugated paperboard containers are less costly to make and generally can be collapsed for compact storage and shipment. However, when filled with a fluid product the sidewalk of the container may bulge outwardly, and depending upon the size of the container and weight of the material used in its construction it may be difficult to set up. Further, a flexible bag liner is commonly used when a fluid material is to be contained, and unless special consideration is given to how the container is constructed, the liner may be damaged by elements of the container protruding into the interior of the container.
[0005] Bulk containers may be palletized for ease and convenience of handling, and it is desirable that the container or containers efficiently fit the pallet, i.e. that they do not overhang the edges of the pallet, or the edges of the pallet do not extend an excessive distance beyond the perimeter of the container or containers supported thereon. Pallets typically utilized are 40×48 or 44×44 or 44×54 inches in size and are square or rectangular in shape. Cylindrical drums do not efficiently fit a pallet because the circular footprint of the drum leaves void spaces between adjacent drums and at the corners of the pallet. Conventionally constructed square or rectangular containers of corrugated paperboard can be sized to fit a pallet, but if the sidewalls bulge outwardly they can extend beyond the perimeter of the pallet and be subject to damage.
[0006] Conventional corrugated paperboard containers strong enough to hold fluid material are either difficult to set up from a flattened condition and/or are too hard to manufacture and/or are too expensive for the end-user. Bulging sidewalls and difficulty in setting them up from a knocked down or flattened condition are the major problems with conventional designs.
[0007] There is need, therefore, for a bulk container made of corrugated paperboard that can take the place of a 20 to 80 gallon fibre drum or metal barrel, which can ship flat and be easily opened up for filling, and once it is empty, knocked down flat again for either re-use or recycling. Further, it would be desirable to have a container that can fit four on a pallet, that is reinforced against bulging of the sidewalls, and that maintains proper containment thereby eliminating potential contamination.
DISCLOSURE OF THE INVENTION
[0008] The present invention solves the foregoing problems through a combination of features, including cross lamination of a corrugated inner liner and an outer component, double score profiles on the 180 degree folds, use of re-enforcing tape such as Sesame Tape or a comparable re-enforcing strand in the liner and in the outer component, with the reinforcing tape extending perpendicular to the respective corrugations in the liner and in the outer component, and pre-breaking of the scores in the liner before lamination with the outer component. The cross lamination of the inner liner and outer component, together with the cross-hatch pattern created by the direction of the reinforcing tape or strands, fortifies the sidewalls against bulge and permits use of lower grades of material in the cross corrugation liner.
[0009] In a preferred embodiment of the invention the container is sized so that four of them can fit on a single pallet. Although the structural limit to a container is governed by the machines used to produce the corrugated fibreboard and the laminator with which the components are joined, the smaller size containers are difficult to fabricate so that they can be shipped in a knocked down condition and easily erected by the user. Pre-breaking the scores of the cross laminated inner liner before it is laminated to the outer component provides ease of fabrication and makes it easier for the end-user to open up the container from a knocked down condition. By pre-breaking the scores deeper definition is given to the body scores and the surface tension is reduced when the panels are folded to form the container. In accordance with the invention, an inner jig is employed during the folding operation at the point of closing the glue joints on the container. The jig helps to form a more uniform geometry by forcing the 180 degree fold ends into two 90 degree pairs of double score features at the vertical corners of the container.
[0010] The resistance to folding of bulk containers, especially the smaller sizes that are in high demand, is of paramount concern, and has been one of the major weaknesses of previous designs. Resistance to folding is created by the small panel sizes and the laminated construction. To overcome this resistance in the present invention, the scores in the inner liner are pre-broken before the liner is laminated to the outer component, and double scores are placed at the point of the 180 degree folds. The double scores lessen the surface tension on the outermost facing, and each of the double scores, individually, only has to fold 90 degrees in the container of the invention, together forming the 180 degree fold.
[0011] In a preferred embodiment the container of the invention has an interlocking bottom flap construction that minimizes the risk of failure during handling, and avoids pinching of a bag liner when a bag is used. The interlocking bottom flaps are designed to provide trouble-free continuous performance during handling even when liquids are stored in the container. The interlocking bottom flaps include a pair of opposed intermediate or inner flaps that provide a full overlap on the inside of the container bottom, with a smooth surface to prevent pinching a bag liner and causing a leak when a bag is used inside the container. Both intermediate flaps have perf scores (also known as cut and crease) just past the points of overlap of the intermediate flaps to assist the user in moving the flaps to their operative positions by preventing binding on the outer flaps which interlock. The interlocking structure of the outer flaps comprises a narrowed tab on the end edge of one outer flap, and a shaped slot adjacent the end edge of the opposing outer flap. The tab has rounded corners to allow entry into the opposing slot, and the shape of the slot inhibits bending of the tab during use. The outer flap that contains the slot also has angled perf scores to facilitate bending of this flap down into the container far enough to permit the tab to be engaged in the slot during set-up. Once engaged, the two interlocked flaps are pulled back up to create a stable flat surface on which the container rests during use. The shaped slot incorporates an arc so that the slot has a generally chevron shape, rather than the typical linear or rectangular geometry that is commonly seen in similar interlocks. Conventionally shaped slots apply force in a straight line across the tab when excessive force is exerted against it from product inside the container, causing the tab to bend. The chevron shape of the slot of the invention helps prevent bending of the tab by dispersing the excessive pressures in a non-linear pattern.
[0012] The liner can be any flute combination, such as C, B, A, AA, AC, BC, AB, AAA, ACA, CAA, CBA, etc, and combinations thereof. The outer half-slotted-container (HSC) of the invention also can comprise any of the same flute combinations. Selection of the flute combinations is governed by the desired performance level of containment and stacking strength.
[0013] The container of the invention can have any dimensions and any rectangular shape tailored to whatever a customer may want, being limited only by a manufacturer's ability to fabricate the container with the attributes of the invention disclosed herein.
[0014] Although the preferred construction has an interlocking, full overlapping bottom flap construction, it could comprise a set of partial flaps or flanges, if desired. A full bottom could also be constructed, but without the overlap that normally would be used in an application for liquid transport.
[0015] The preferred embodiment of container according to the invention has interlocking flanges at its upper end, but it could be constructed with no flaps or flanges at its upper end, or partial flaps without interlocking characteristics, or a full flap closure with or without any overlap. The preferred embodiment comprises interlocking flanges such as shown in U.S. Pat. No. 6,076,734, the disclosure of which is incorporated in full herein by reference. Interlocking top flanges in combination with the other features described earlier aids in the needed sidewall rigidity, and in turn helps prevent bulging and ensures proper product containment. Proper containment is necessary for secure storage and transport, whether the product is a food or an industrial ingredient.
[0016] Although the preferred embodiment has two reinforcing strands of tape (Sesame Tape or comparable types or brands) on the outer component and four strands on the cross laminated inner liner, the container of the invention could have any number of reinforcing strands, from no strands to eight strands per component, limited by the functionality for customer use and the manufacturer's ability to produce.
[0017] Further, a variety of flute configurations and combinations of the outer corrugated and the inner cross laminated corrugated could be used, such as singlewall (A-flute, B-flute, C-flute or any other flute size currently available) outer, and a cross laminated triplewall (AAA, ACA, CAA, CBA or any other flute combination currently available) inner. The inner cross corrugation could be any flute combination of doublewall and still provide adequate flexural rigidity which is needed for the practical use of the container.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] The foregoing, as well as other objects and advantages of the invention, will become apparent from the following detailed description when taken in conjunction with the accompanying drawings, wherein like reference characters designate like parts throughout the several views, and wherein:
[0019] FIG. 1 is a partially exploded top perspective view of four containers according to the invention resting on a pallet.
[0020] FIG. 2 is a top plan view of a blank for making the outer component of the container of the invention.
[0021] FIG. 3 is a top plan view of a blank for making the inner liner of the container of the invention.
[0022] FIG. 4 is a top plan view of a blank for making a cap for use on the container of the invention.
[0023] FIG. 5 is a top plan view showing the inner liner laminated to the outer component preparatory to folding the container and gluing the glue flaps together.
[0024] FIG. 6 shows the container in an inverted position and depicts the series of steps performed in folding the interlocking bottom flaps into operative interlocked position.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0025] A container made in accordance with a preferred embodiment of the invention is indicated generally at 10 in FIG. 1 , wherein four of the containers are shown resting on a pallet P.
[0026] The container is rectangular in shape and has four sidewalls 12 , 13 , 14 and 15 , joined together along vertical scores 16 A, 16 B, 16 C and 16 D at the corners, an open top end partially closed by interlocking top flanges 17 A, 17 B and 18 A, 18 B, and as seen best in FIG. 6 a closed bottom end 19 . A cap 20 is placed over the upper end of each container and in FIG. 1 is shown removed from one of them.
[0027] Construction of the container is best understood with reference to FIGS. 2-6 .
[0028] FIG. 2 shows a blank B 1 for making the outer component 21 of the container. The blank comprises four sidewall panels 12 , 13 , 14 and 15 joined together along the respective scores 16 A, 16 B and 16 C, with a glue flap 22 foldably joined to one end edge of the blank along fold 16 D which effectively joins panel 12 to panel 15 when the container is glued up. The scores 16 A and 16 B are double scores as more fully described and illustrated in applicant's prior U.S. Pat. No. 4,693,413, the disclosure of which is incorporated in full herein by reference. As described in that patent, the scores 16 A and 16 B extend along those corners joining sidewall panels that move through 180 degrees between the unfolded position of the blank and the folded flat position of a container made from the blank.
[0029] The partial top flanges 17 A, 17 B and 18 A, 18 B are foldably joined to top edges of the respective sidewall panels along fold lines 23 . The top flanges are constructed substantially the same as and function in substantially the same way as described and shown in applicant's prior U.S. Pat. No. 6,076,730, the disclosure of which is incorporated in full herein by reference. Thus, opposite side edges of flanges 18 A and 18 B are cut away along curvilinear lines to define a locking tab 24 on the outer end edge thereof and rounded shoulders 25 on the opposite side edges. Flanges 17 A and 17 B have notches 26 cut in their outer end edges adjacent the opposite sides thereof, defining rounded corners 27 on opposite side edges of the flanges. As seen best in FIG. 1 , when the flanges are folded into operative position the corners 27 on flanges 17 A, 17 B engage beneath shoulders 25 on flanges 18 A, 18 B, and the side edges of tabs 24 engage in the notches 26 , with the tabs 24 on flanges 18 A, 18 B lying beneath the adjacent edges of flanges 17 A, 17 B, interlocking the flanges together. It will be noted that the notches 26 and corners 27 in the present invention are rounded as distinguished from the rectilinear shape of these elements in U.S. Pat. No. 6,076,730, facilitating alignment and engagement of the interlocking portions of the flanges when they are being folded into their interlocking positions.
[0030] In the preferred embodiment shown in FIG. 2 , substantially identical bottom flaps 30 A and 30 B are foldably joined to bottom edges of respective sidewall panels 12 and 14 along folds 31 , and bottom flaps 32 and 33 are foldably joined to bottom edges of respective sidewall panels 13 and 15 along folds 34 . In a container erected from the blank the flaps 30 A and 30 B comprise inner flaps and the flaps 32 and 33 comprise outer flaps.
[0031] The flaps 30 A and 30 B are rectangular in shape, and a line of perforations define a perf score 35 across each flap adjacent but spaced from the folds 31 . When a container is erected from the blank, the flaps 30 A, 30 B are disposed in opposed relationship to one another and each flap extends most of the way across the bottom of the container, with the free end edge of each flap terminating just short of a respective perf score 35 in the opposed flap. This arrangement helps facilitate folding of the flaps into operative position as depicted in FIG. 6 . The side edge of flap 30 A is recessed slightly at 36 A adjacent glue flap 22 , and one side edge of flap 30 B is recessed slightly at 36 B adjacent its outer end edge. These recessed areas provide clearance for the glue flap when the flaps are folded into their operative positions in a container erected from the blank
[0032] The side edges of flap 32 are cut away along curvilinear lines to define a narrowed locking tab 37 on the outer end edge thereof, and rounded shoulders 38 on opposite side edges. The locking tab and shoulders cooperate with flap 33 as described below to lock the bottom flaps in operative position across the bottom of a container erected from the blank.
[0033] Bottom flap 33 is generally rectangular in shape and a pair of diagonal fold scores 40 and 41 extend from opposite corners of the flap closely adjacent the fold 34 to the outer end edge thereof in inwardly spaced relation to opposite side edges of the flap, defining triangularly shaped corners 42 . A generally chevron shaped slot 43 is formed in approximately the middle of the flap 33 for receiving the locking tab 37 on flap 32 as described hereinafter.
[0034] In the preferred embodiment as shown in FIG. 2 , a pair of reinforcing strands 45 of Sesame Tape or other reinforcing strand known in the art extends across the blank from one end edge to the other approximately midway between the top and bottom edges thereof. As indicated by the arrow “A” in FIG. 2 , the corrugations of the outer component 21 extend perpendicular to the top and bottom edges of the blank, and the reinforcing strands extend perpendicular to the corrugations.
[0035] A blank B 2 for making the inner liner 50 of the container of the invention is shown in FIG. 3 . The blank B 2 is rectangular in shape and comprises four sidewall panels 51 , 52 , 53 and 54 joined together along respective scores 16 A′, 16 B′ and 16 C′, with a glue flap 55 foldably joined to one end edge of the blank along fold 16 D′ and which effectively joins panel 51 to panel 54 when the container is glued up. The scores 16 A′ and 16 B′ are double scores as more fully described and illustrated in applicant's prior U.S. Pat. No. 4,693,413, the disclosure of which is incorporated in full herein by reference. In a container erected from the blank, the scores 16 A′ and 16 B′ in the liner extend contiguous with the scores 16 A and 16 B in the outer component, and the scores 16 C′, 16 D′ extend contiguous with the scores 16 C, 16 D, respectively. The scores 16 A′, 16 B′, 16 C′ and 16 D′ in the liner are pre-broken with a jig (not shown) prior to lamination of the liner 50 to the outer component 21 to facilitate fabrication of the container and to make it easier for a user to open up a flattened container into its operative position. In the preferred embodiment as shown in FIG. 3 , a first pair of reinforcing strands 56 of Sesame Tape or other reinforcing strands known in the art is applied to a midportion of sidewall panel 52 , extending from the bottom edge thereof to the top edge, and at least one reinforcing strand 56 (two are shown in FIG. 3 and one in FIG. 5 ) is applied to a midportion of panel 54 , extending from the bottom edge to the top edge of that panel. As indicated by the arrow “B”, it will be noted that the corrugations in the liner extend in a direction perpendicular to the corrugations in the outer component. Thus, the reinforcing strands in the liner extend perpendicular to the corrugations in the liner, and as seen best in FIG. 5 they extend perpendicular to the reinforcing strands in the outer component in a container erected from the blank.
[0036] FIG. 5 shows the inner liner 50 laminated to the outer component 21 to form a laminated blank 57 from which the container is erected. It will be noted that the liner is shifted to the left as viewed in this figure, with the glue flap 55 on the liner projecting beyond the glue flap 22 on the outer component, and the opposite end of the liner inset relative to the adjacent end of the outer component, defining a space 58 for attachment of the glue flap 55 .
[0037] To set up a container from its flattened condition to its expanded operative condition, it is opened into a tubular configuration and the partial top flaps are folded into their operative interlocked position as described previously herein. The container is then inverted so that it rests on its top end, and the bottom flaps are folded into their operative interlocked positions as depicted in FIG. 6 . Flaps 30 A and 308 are first folded inwardly into the container, followed by inward folding of flap 33 and then flap 32 . The flaps are pressed downwardly into the container until the locking tab 37 engages in slot 43 , and the flaps are then pulled outwardly into a generally flat position across the bottom of the container. It will be noted that the perf scores 35 in flaps 30 A and 30 B and the folds 40 and 41 in flap 33 enable these flaps to deform slightly during the folding operation to facilitate set up of the container.
[0038] A blank B 3 for making the cap 20 is shown in FIG. 4 . The blank comprises a rectangular center panel 60 with substantially identical end flaps 61 and 62 foldably joined to opposite end edges thereof along folds 63 , and substantially identical side flaps 64 and 65 foldably joined to opposite side edges thereof along folds 66 . As seen in FIG. 1 , the flaps 61 , 62 and 64 , 65 interlock with one another to form a cap skirt 67 . The interlocking construction of cap 20 is substantially the same as that for the liner tray 110 disclosed in U.S. Pat. No. 7,172,108. Thus, flaps 61 and 62 each has an assembly flap 68 on opposite side edges thereof, with an outer corner cut away at 69 to define a locking tab 70 that is inserted into angled slit cuts 71 in the flaps 64 and 65 adjacent opposite ends thereof.
[0039] While particular embodiments of the invention have been illustrated and described in detail herein, it should be understood that various changes and modifications may be made in the invention without departing from the spirit and intent of the invention as defined by the appended claims.
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A reinforced cross laminated corrugated paperboard bulk container has an outer component with corrugations running in a first direction, and an inner liner laminated to the outer component, with the liner having corrugations extending perpendicular to the corrugations in the outer component. Reinforcing strands are in both the liner and the outer component, extending perpendicular to the respective corrugations thereof. Interlocking top flanges are on the top edges of the outer component, and interlocking bottom flanges are on the bottom edges thereof. The interlocking bottom flanges include a chevron shaped locking slot in one flange and a locking tab on an opposed bottom flange. Folds extend across the bottom flanges to enable them to deflect and slide relative to one another during set up of the container. Vertical scores in the liner are pre-broken prior to laminating it to the outer component.
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BACKGROUND OF THE INVENTION
In modern contemporary fencing installations it is not unusual to include a swinging gate or door to provide access to the area being enclosed. Usually the swinging gate is provided with a “bolt” which engages and locks into a thumb latch which is mounted on the stationary adjoining wall or post. These closure installations work acceptably well until some misalignment occurs between the bolt and the latch. The misalignment can be severe in instances where the length of the gate exceeds a few feet. Misalignment frequently occurs in areas subject to frost heaving of the gate and/or the fence or post on which the thumb latch (keeper) is mounted. The frost heaving can be embarrassing because it may cause the gate to “stick” in the closed position due to the force transmitted to the latch by the misaligned bolt. The same situation occurs in hurried installations where the gate post upon which the gate is hinged settles due to improper packing of the earth about the post during construction.
Upon forcing a gate to open once misalignment has occurred, it is difficult if not impossible to close the gate and engage the bolt with the thumb latch due to the lack of registration of the bolt and latch.
It is usually necessary to remove and re-mount the latch assembly (or the bolt) to permit the gate to be closed and latched in the secure position after the misalignment of the latch and bolt has occurred. This invention will compensate for the misalignment which occurs due to faulty installation or during heaving resulting from frost penetration.
SUMMARY OF THE INVENTION
This invention allows for substantial vertical misalignment of the bolt and latch assembly of a garden gate type lock and will permit latching and unlatching of the bolt despite reasonable relative vertical misalignment of the gate and latching post.
This latch assembly comprises a standard thumb latch keeper which is permanently mounted on a stationary post or wall and wherein a latch bolt is arranged to pivot about the end of the bolt remote from the keeper so as to engage the latch keeper.
The latch assembly thus comprises a bolt which will be found to be somewhat longer than a standard latch bolt, but the end of the bolt remote from the latch is pivoted to allow the bolt to pivot in a vertical plane, and the bolt will be maintained within a guide having a slot which confines the pivoting motion of the bolt to that in a vertical plane.
The bolt will pivot in a vertical plane within the guide which will compensate for a substantial amount of misalignment between the gate and the stationary post or wall.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a pivoting bolt gate latch of this invention mounted on a gate and post.
FIG. 2 is a perspective view of the latch of this invention.
FIG. 3 is a development of the base of the latch of this invention.
FIG. 4 is a close-up perspective view of the gate latch of this invention.
FIG. 5 shows a perspective view of an alternative embodiment of this invention.
FIG. 6 shows yet another embodiment of this invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows gate 10 and a stationary post member 12 on which the latch bar assembly 14 and the keeper 16 are mounted. Latch bar assembly 14 shows a pivoting latch bar 18 mounted on pivot 20 . The latch bar 18 is held in keeper 16 by a thumb release member 22 . In this Figure, the post 12 is shown in a somewhat sunken position.
FIG. 2 shows the latch bar member 14 in greater detail. Member 14 comprises a one piece base 24 having mounting holes 26 . Base 14 also comprises an integral upstanding guide portion 28 having a slot 30 formed therein to receive pivoting latch bar 18 therein. A base return lip 32 is formed by bending the upstanding guide portion 28 at 34 to form a large flat surface to provide an enhanced bearing surface for pivoting latch 18 . The large flat exposed surface 32 is provided also for the safety of persons using the gate latch device.
Base 14 is provided with a raised dimple 36 on which pivot 20 is mounted.
FIG. 1 shows a gate installation in which for reason unknown, the post 12 has sunk somewhat. The pivoting latch 18 is able to engage keeper 16 by its ability to drop in slot 30 to accommodate the sunken position of keeper 16 on post 12 . This position is represented by the position of latch bar 18 shown in solid lines in FIG. 2 .
FIG. 3 shows the latch assembly having the keeper 16 engaging the pivoting latch bar 18 . Keeper 16 comprises a base 40 having an upstanding flange 42 upon which thumb latch 44 is pivoted about pivot 46 .
Flange 42 is provided with a “V” shaped notch to guide pivoting latch bar 18 into engagement with thumb latch 44 . Screws 48 secure the latch and keeper to their respective support members 10 and 12 .
FIG. 4 shows an alternative quick mounted for the latch member on a tubular gate member having a square cross section. Here gate post member 50 is engaged by a two piece base plate combination assembly 54 and 56 . In this installation the base 54 is engaged by clasp 56 . Base 54 is provided with slot 58 through which tongue 60 of clasp 56 is captured. Clasp 56 is shaped to surround post 50 and lip 58 is provided for attachment of bolts 60 of base 54 through clasp 56 to secure the member 52 to post 50 . This method of attachment is quick, easy and robust.
Pivoting latch bar 18 is guided by slot 30 of base 54 . Return lip 62 provides additional bearing surface for latch bolt 18 and a safety reinforcement as well. The presence of the lip 62 presents a flat surface parallel to the base 54 which avoids the narrow projecting lip present in most prior art devices. Besides strengthening the base of the latch assembly, this lip is designed to eliminate injuries to persons using the latch of this invention.
FIG. 5 shows a modification of the gate latch 72 of this invention to accommodate mounting on a round post 70 . Base 74 of latch 72 is shaped in a similar manner of the latch 52 of FIG. 4 . Base 74 is provided with a slight concavity at 76 to give more surface contact with gate post 70 . Clasp 78 is made to have tongue 80 pass through slot 82 of base 74 of latch 72 . Bolts 84 serve to close clasp 78 on post 70 to complete the mounting of latch 72 on post 70 .
A pivot 86 provides the center of rotation for latch 88 . Latch 88 is guided in slot 90 of base 74 . Lip 92 functions to eliminate any sharp projections protruding from latch 72 and increase the strength of the base member 74 .
In summary, the latch of this invention provides a base which is produced to have three integral cooperating flat surfaces to produce a strong base having a smoothly operating movement which is capable of compensating for settling of gate or latching posts. The latch is so produced so it can compensate for large misalignments of latch and keeper due to frost and settlement of gate and post members.
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This application reveals a gate latch assembly in which a pivoting bolt permits substantial misalignment occur between the bolt and latch members and yet permit successful latching of the assembly.
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CROSS REFERENCE TO RELATED APPLICATIONS
Reference is made to commonly assigned, co-pending U.S. patent applications:
Ser. No. 10/180,187 by Bringley et al., filed of even date herewith entitled “Ink Jet Printing Method”; Ser. No. 10/180,638 by Sharma et al., filed of even date herewith entitled “Ink Jet Recording Element”; and Ser. No. 10/180,373 by Bringley et al., filed of even date herewith entitled “Ink Jet Printing Method”; Ser. No. 10/180,752 by Sharma et al., filed of even date herewith entitled “Ink Jet Recording Element”; Ser. No. 10/180,184 by Bringley et al., filed of even date herewith entitled “Ink Jet Printing Method”; Ser. No. 10/180,395 by Sharma et al., filed of even date herewith entitled “Ink Jet Recording Element”; and Ser. No. 10/180,179 by Bringley et al., filed of even date herewith entitled “Ink Jet Printing Method”.
FIELD OF THE INVENTION
The present invention relates to an ink jet recording element containing a stabilizer.
BACKGROUND OF THE INVENTION
In a typical ink jet recording or printing system, ink droplets are ejected from a nozzle at high speed towards a recording element or medium to produce an image on the medium. The ink droplets, or recording liquid, generally comprise a recording agent, such as a dye or pigment, and a large amount of solvent. The solvent, or carrier liquid, typically is made up of water and an organic material such as a monohydric alcohol, a polyhydric alcohol or mixtures thereof.
An ink jet recording element typically comprises a support having on at least one surface thereof an ink-receiving or image-receiving layer, and includes those intended for reflection viewing, which have an opaque support, and those intended for viewing by transmitted light, which have a transparent support.
An important characteristic of ink jet recording elements is their need to dry quickly after printing. To this end, porous recording elements have been developed which provide nearly instantaneous drying as long as they have sufficient thickness and pore volume to effectively contain the liquid ink. For example, a porous recording element can be manufactured by coating in which a particulate-containing coating is applied to a support and is dried.
When a porous recording element is printed with dye-based inks, the dye molecules penetrate the coating layers. However, there is a problem with such porous recording elements in that the optical densities of images printed thereon are lower than one would like. The lower optical densities are believed to be due to optical scatter which occurs when the dye molecules penetrate too far into the porous layer. Another problem with a porous recording element is that atmospheric gases or other pollutant gases readily penetrate the element and lower the optical density of the printed image causing it to fade.
EPA 1174279A teaches the use of zinc oxide in inkjet recording elements to improve light stability. However, there is problem with such elements in that they do not provide protection against environmental gasses such as ozone.
EPA 988993A and EPA 893270A disclose the use of aluminum hydrate and aluminum hydroxides in ink jet recording elements. However, there is a problem with these elements in that they do not provide good image stability.
It is an object of this invention to provide an ink jet recording element that, when printed with dye-based inks, provides superior optical densities, good image quality, image stability and has an excellent dry time.
SUMMARY OF THE INVENTION
This and other objects are achieved in accordance with the invention which comprises an ink jet recording element containing a metal hydroxide salt,
(M 2+ )(OH) a (A p − ) b .xH 2 O;
wherein:
M 2+ is at least one metal ion having a 2+ oxidation state; A is an organic or inorganic anion; p is 1 or 2; and x is equal to or greater than 0; and a and b comprise rational numbers as follows: 0<a<2 and 0<b<2 so that the charge of M 2+ is balanced.
By use of the invention, an ink jet recording element is obtained that, when printed with dye-based inks, provides superior optical densities, good image quality and has an excellent dry time.
DETAILED DESCRIPTION OF THE INVENTION
In a preferred embodiment of the invention, the metal hydroxide salt described above is located in the image-receiving layer. In another preferred embodiment, M can be two different metal ions such as zinc and tin. In another preferred embodiment, the metal hydroxide salt described above is in a particulate form. In another preferred embodiment, a is greater than 0.5 and b is less than 1.5.
In yet still another preferred embodiment of the invention, A p− is an organic anion such as R—COO − , R—O − , R—SO 3 − , R—OSO 3 − or R—O—PO 3 − where R is an alkyl or aryl group. In another preferred embodiment, A p− is an inorganic anionic such as I − , Cl − , Br − , F − , ClO 4 − , NO 3 − , CO 3 2− or SO 4 2− . The particle size of the salt described above is less than about 5 μm, preferably less than about 1 μm.
M 2+ hydroxide salts can be synthesized from a variety of synthetic routes, such as addition of base to metal salts, reacting a metal salt with a metal oxide or through ion exchange. Some of the M 2+ hydroxide salts form layered structures and are commonly referred to as hydroxy double salts. However, M 2+ hydroxides can also exist as polycationic nanoparticles. It is possible to control particle size, shape and structure of M 2+ hydroxide salts using appropriate anions or metal ions or synthetic routes.
Examples of M 2+ useful in the invention include zinc, magnesium, barium, calcium, tin, nickel, cobalt and copper.
Specific examples of M 2+ hydroxide salts include zinc hydroxy double salts such as Zn 5 (OH) 8 (A p− ), wherein A p− is Cl, Br, nitrate, acetate or propionate.
In a preferred embodiment of the invention, the image-receiving layer is porous and also contains a polymeric binder in an amount insufficient to alter the porosity of the porous receiving layer. In another preferred embodiment, the polymeric binder is a hydrophilic polymer such as poly(vinyl alcohol); poly(vinyl pyrrolidone), gelatin, cellulose ethers, poly(oxazolines), poly(vinylacetamides), partially hydrolyzed poly(vinyl acetate/vinyl alcohol), poly(acrylic acid), poly(acrylamide), poly(alkylene oxide), sulfonated or phosphated polyesters and polystyrenes, casein, zein, albumin, chitin, chitosan, dextran, pectin, collagen derivatives, collodian, agar-agar, arrowroot, guar, carrageenan, tragacanth, xanthan, rhamsan and the like. In still another preferred embodiment of the invention, the hydrophilic polymer is poly(vinyl alcohol), hydroxypropyl cellulose, hydroxypropyl methyl cellulose, or a poly(alkylene oxide). In yet still another preferred embodiment, the hydrophilic binder is poly(vinyl alcohol).
In addition to the image-receiving layer, the recording element may also contain a base layer, next to the support, the function of which is to absorb the solvent from the ink. Materials useful for this layer include particles, polymeric binder and/or crosslinker.
The support for the inkjet recording element used in the invention can be any of those usually used for ink jet receivers, such as resin-coated paper, paper, polyesters, or microporous materials such as polyethylene polymer-containing material sold by PPG Industries, Inc., Pittsburgh, Pa. under the trade name of Teslin®, Tyvek® synthetic paper (DuPont Corp.), and OPPalyte® films (Mobil Chemical Co.) and other composite films listed in U.S. Pat. No. 5,244,861. Opaque supports include plain paper, coated paper, synthetic paper, photographic paper support, melt-extrusion-coated paper, and laminated paper, such as biaxially oriented support laminates. Biaxially oriented support laminates are described in U.S. Pat. Nos. 5,853,965; 5,866,282; 5,874,205; 5,888,643; 5,888,681; 5,888,683; and 5,888,714, the disclosures of which are hereby incorporated by reference. These biaxially oriented supports include a paper base and a biaxially oriented polyolefin sheet, typically polypropylene, laminated to one or both sides of the paper base. Transparent supports include glass, cellulose derivatives, e.g., a cellulose ester, cellulose triacetate, cellulose diacetate, cellulose acetate propionate, cellulose acetate butyrate; polyesters, such as poly(ethylene terephthalate), poly(ethylene naphthalate), poly(1,4-cyclohexanedimethylene terephthalate), poly(butylene terephthalate), and copolymers thereof; polyimides; polyamides; polycarbonates; polystyrene; polyolefins, such as polyethylene or polypropylene; polysulfones; polyacrylates; polyetherimides; and mixtures thereof. The papers listed above include a broad range of papers, from high end papers, such as photographic paper to low end papers, such as newsprint. In a preferred embodiment, polyethylene-coated paper is employed.
The support used in the invention may have a thickness of from about 50 to about 500 μm, preferably from about 75 to 300 μm. Antioxidants, antistatic agents, plasticizers and other known additives may be incorporated into the support, if desired.
In order to improve the adhesion of the ink-receiving layer to the support, the surface of the support may be subjected to a corona-discharge treatment prior to applying the image-receiving layer.
Coating compositions employed in the invention may be applied by any number of well known techniques, including dip-coating, wound-wire rod coating, doctor blade coating, gravure and reverse-roll coating, slide coating, bead coating, extrusion coating, curtain coating and the like. Known coating and drying methods are described in further detail in Research Disclosure no. 308119, published December 1989, pages 1007 to 1008. Slide coating is preferred, in which the base layers and overcoat may be simultaneously applied. After coating, the layers are generally dried by simple evaporation, which may be accelerated by known techniques such as convection heating.
In order to impart mechanical durability to an ink jet recording element, crosslinkers which act upon the binder discussed above may be added in small quantities. Such an additive improves the cohesive strength of the layer. Crosslinkers such as carbodiimides, polyfunctional aziridines, aldehydes, isocyanates, epoxides, polyvalent metal cations, and the like may all be used.
To improve colorant fade, UV absorbers, radical quenchers or antioxidants may also be added to the image-receiving layer as is well known in the art. Other additives include inorganic or organic particles, pH modifiers, adhesion promoters, rheology modifiers, surfactants, biocides, lubricants, dyes, optical brighteners, matte agents, antistatic agents, etc. In order to obtain adequate coatability, additives known to those familiar with such art such as surfactants, defoamers, alcohol and the like may be used. A common level for coating aids is 0.01 to 0.30% active coating aid based on the total solution weight. These coating aids can be nonionic, anionic, cationic or amphoteric. Specific elements are described in MCCUTCHEON's Volume 1: Emulsifiers and Detergents, 1995, North American Edition.
The ink receiving layer employed in the invention can contain one or more mordanting species or polymers. The mordant polymer can be a soluble polymer, a charged molecule, or a crosslinked dispersed microparticle. The mordant can be non-ionic, cationic or anionic.
The coating composition can be coated either from water or organic solvents, however water is preferred. The total solids content should be selected to yield a useful coating thickness in the most economical way, and for particulate coating formulations, solids contents from 10–40% are typical.
Ink jet inks used to image the recording elements of the present invention are well-known in the art. The ink compositions used in ink jet printing typically are liquid compositions comprising a solvent or carrier liquid, dyes or pigments, humectants, organic solvents, detergents, thickeners, preservatives, and the like. The solvent or carrier liquid can be solely water or can be water mixed with other water-miscible solvents such as polyhydric alcohols. Inks in which organic materials such as polyhydric alcohols are the predominant carrier or solvent liquid may also be used. Particularly useful are mixed solvents of water and polyhydric alcohols. The dyes used in such compositions are typically water-soluble direct or acid type dyes. Such liquid compositions have been described extensively in the prior art including, for example, U.S. Pat. Nos. 4,381,946; 4,239,543 and 4,781,758, the disclosures of which are hereby incorporated by reference.
Although the recording elements disclosed herein have been referred to primarily as being useful for ink jet printers, they also can be used as recording media for pen plotter assemblies. Pen plotters operate by writing directly on the surface of a recording medium using a pen consisting of a bundle of capillary tubes in contact with an ink reservoir.
The following examples are provided to illustrate the invention.
EXAMPLES
Example 1
Dye Stability Evaluation Tests
The dye used for testing was a magenta colored ink jet dye having the structure shown below. To assess dye stability on a given substrate, a measured amount of the ink jet dye and solid particulates or aqueous colloidal dispersions of solid particulates (typically about 10%–20.0% by weight solids) were added to a known amount of water such that the concentration of the dye was about 10 −5 M. The solid dispersions containing dyes were carefully stirred and then spin coated onto a glass substrate at a speed of 1000–2000 rev/min. The spin coatings obtained were left in ambient atmosphere with fluorescent room lighting (about 0.5 Klux) kept on at all times during the measurement. The fade time was estimated by noting the time required for complete disappearance of magenta color as observed by the naked eye or by noting the time required for the optical absorption to decay to less than 0.03 of the original value. The results are shown in Table 1.
Comparative Coatings C-1 to C-6 (Non-metal 2+ hydroxide salts)
Inorganic particles of Al 2 O 3 , SiO 2 , ZnO, Zn(OH) 2 , laponite and montmorillonite were purchased from commercial sources as fine particles or as colloidal particulate dispersions and were used to evaluate the stability of ink jet dyes in comparison with the materials employed in the present invention. The particulates were then coated and tested as described above.
Inventive Coatings I-1 to I-7
I-1. 81.5 g of ZnO (1.0 mol) (J.T. Baker Co.) was suspended in 100 ml of distilled deionized water. To this suspension, 148.5 g of Zn(NO 3 ) 2 .6H 2 O (0.5 mol) dissolved in 500 mL of distilled deionized water was added rapidly (within 5–10 min.). The resultant suspension was stirred vigorously for five days at 60° C. The final product, Zn 5 (OH) 8 (NO 3 ) 2 .2H 2 O, was filtered and washed with copious amounts of distilled water and air dried. The final product was dispersed in distilled water and used for evaluating the stability of ink jet dyes as described above.
I-2. 162.8 g of ZnO (2.0 mol) (J.T. Baker Co.) was suspended in 200 ml of distilled deionized water. To this suspension, 219.5 g of Zn(CH 3 COO) 2 .6H 2 O (1.0 mol) dissolved in 500 mL of distilled deionized water was added rapidly (within 5–10 min). The resultant suspension was stirred vigorously 36 h at 60° C. The final product, Zn 5 (OH) 8 (CH 3 COO) 2 .2H 2 O was filtered and washed with copious amounts of distilled water and air dried. The final product was dispersed in distilled water and used for evaluating the stability of ink jet dyes as described above.
I-3. 40.6 g of ZnO (0.5 mol), (Alfa Aesar Co.), 325 mesh powder, was suspended in 50 ml of distilled deionized water. To this suspension, 35.5 g of ZnCl 2 (0.26 mol) dissolved in 250 mL of distilled deionized water was added rapidly (within 5–10 min.). The resultant suspension was stirred vigorously for two days at room temperature. The final product, Zn 5 (OH) 8 (Cl) 2 .2H 2 O, was filtered and washed with copious amounts of distilled water and air dried. The final product was dispersed in distilled water and used for evaluating the stability of ink jet dyes as described above.
I-4. 40.6 g of ZnO (0.5 mol), (Alfa Aesar Co.), 325 mesh powder, was suspended in 50 ml of distilled deionized water. A separate solution was made by dissolving 70.0 g of Zn(NO 3 ) 2 (0.0235 ml) and 4.5 g of Co(NO 3 ) 2 (0.0015 mol) in 250 mL of distilled deionized water. The mixed metal nitrate solution was filtered and then added rapidly to this suspension of ZnO. The final reaction mixture was vigorously stirred for two days at room temperature. The product, (Zn 5-x , Co x )(OH) 8 (NO 3 ) 2 .2H 2 O: was filtered and washed with copious amounts of distilled water and air dried. The final product was dispersed in distilled water and used for evaluating the stability of ink jet dyes as described above.
I-5. 20.35 g of ZnO (0.25 mol), (JT Baker Co.) was suspended in 50 ml of distilled deionized water. To this suspension, 23.1 g of zinc sulfate mono hydrate (0.128 mol) dissolved in 125 mL of distilled deionized water was added rapidly (within 5–10 min.). The resultant suspension, 3Zn(OH) 2 .ZnSO 4 .4H 2 O, was stirred vigorously for two days at room temperature. The final product was dispersed in distilled water and used for evaluating the stability of ink jet dyes as described above.
I-6. Fine particles of [Zn 5 (OH) 8 (NO 3 ) 2 ].xH 2 O (5.0 g, 0.008 mol) were suspended in 200 ml of distilled water. To this suspension 4.0 g of 1-napthalene sulfonic acid sodium salt (0.017 mol) was added while vigorously stirring the suspension at 60° C. The stirring was continued for 2 days and the final product, Zn 5 (OH) 8 (napthalene sulfonate), was filtered and washed with copious amounts of acetone and air dried. The final product was dispersed in distilled water and used for evaluating the stability of ink jet dyes as described above.
I-7. Fine particles of [Zn 5 (OH) 8 (NO 3 ) 2 ].xH 2 O (5.0 g, 0.008 mol) were suspended in to 200 ml of distilled water. To this suspension 2.5 g of salicylic acid (0.0018 mol) was added at room temperature and the reaction mixture was stirred for 2 days. The final product of this reaction is a physical mixture of hydroxy double salt containing nitrate and salicylate anions, [Zn 5 (OH) 8 (salicylate) y ] x [Zn 5 (OH) 8 (NO 3 )] 1-x . The final product was dispersed in distilled water and used for evaluating the stability of ink jet dyes as described above.
TABLE 1
Coating
Particle
Fade Time
C-1
Al 2 O 3
18 hours
C-2
SiO 2
18 hours
C-3
ZnO
2 days
C-4
Zn(OH) 2
5 days
C-5
Laponite
4 days
C-6
Montmorillonite
18 hours
I-1
Zn 5 (OH) 8 (NO 3 ) 2 .2H 2 O
7 days
I-2
Zn 5 (OH) 8 (CH 3 COO) 2 .2H 2 O
>14 days
I-3
Zn 5 (OH) 8 (Cl) 2 .2H 2 O
6 days
I-4
(Zn 5−x , Co x ) (OH) 8 (NO 3 ) 2 .2H 2 O
2 days
I-5
3Zn(OH) 2 .ZnSO 4 .4H 2 O
2 days
I-6
[Zn 5 (OH) 8 (1-naphthalene
>14 days
sulfonate) y ].xH 2 O
I-7
[Zn 5 (OH) 8 (Salicylate) y ] x
>14 days
[Zn 5 (OH) 8 (NO 3 )] 1−x
The above results show that the salts employed in the elements of the present invention provide superior image stability to ink jet dyes against fade changes as compared to the control elements.
Example 2
Element 1
A coating composition was prepared from 70.0 wt. % of an aqueous colloidal suspension (15.8 wt. % solids) of Zn 5 (OH) 8 (CH 3 COO) 2 .2H 2 O, 2.0 wt. % poly(vinyl alcohol) (Gohsenol® GH-17 from Nippon Gohsei Co.), and 28.0 wt. % water. The relative proportion of Zn 5 (OH) 8 (CH 3 COO) 2 .2H 2 O to PVA is therefore 85/15 by weight. The solution was coated onto a base support comprised of a polyethylene resin coated photographic paper stock, which had been previously subjected to corona discharge treatment, using a calibrated coating knife, and dried to remove substantially all solvent components to form the ink receiving layer.
Element 2
This element was prepared the same as Element 1 except that the coating composition was 73.5 wt. % of an aqueous colloidal suspension (15.0 wt. % solids) of Zn 5 (OH) 8 (Cl) 2 .2H 2 O, 2.0 wt. % poly(vinyl alcohol) (Gohsenol® GH-17 from Nippon Gohsei Co.), and 24.5 wt. % water. (The relative proportion of Zn 5 (OH) 8 (Cl) 2 .2H 2 O to PVA is therefore 85/15 by weight).
Element 3
This element was prepared the same as Element 1 except that the coating composition was 14.8 wt. % Zn 5 (OH) 8 (NO 3 ) 2 .2H 2 O, 0.83 wt. % poly(vinyl alcohol) (Gohsenol® GH-23 from Nippon Gohsei Co.), 1.48 wt. % Dowfac 2A1® surfactant, and 82.9 wt. % water (The relative proportion of Zn 5 (OH) 8 (NO 3 ) 2 .2H 2 O to PVA is therefore 95/5 by weight).
Element 4
This element was prepared the same as Element 1 except that the coating composition was 14.0 wt. % of an aqueous colloidal suspension of Zn 5 (OH) 8 (CH 3 COO) 2 .2H 2 O (15.8 wt. % solids), and 22.0 wt. % silica (a 40 wt. % aqueous colloidal suspension of Nalco2329® (75 nm silicon dioxide particles) from Nalco Chemical Co.), 2.0 wt. % poly(vinyl alcohol) (Gohsenol® GH-17 from Nippon Gohsei Co.), and 62.0 wt. % water. (The relative proportion of Zn 5 (OH) 8 (CH 3 COO) 2 .2H 2 O to silica is 20/80 and that of (Zn 5 (OH) 8 (CH 3 COO) 2 .2H 2 O-silica) particles to PVA is therefore 85/15 by weight).
Element 5
This element was prepared the same as Element 1 except that the coating composition was 14.0 wt. % of an aqueous colloidal suspension of Zn 5 (OH) 8 (CH 3 COO) 2 .2H 2 O (15.8 wt. % solids), 22 wt. % fumed alumina (40 wt. % alumina in water, Cab-O-Sperse® PG003 from Cabot Corporation), 2.0 wt. % poly(vinyl alcohol) (Gohsenol® GH-17 from Nippon Gohsei Co.), and 62.0 wt. % water. (The relative proportion of Zn 5 (OH) 8 (CH 3 COO) 2 .2H 2 O to alumina is 20/80 and that of (Zn 5 (OH) 8 (CH 3 COO) 2 .2H 2 O-alumina) particles to PVA is therefore 85/15 by weight)).
Element 6
This element was prepared the same as Element 1 except that the coating composition was 14.5 wt. % of an aqueous colloidal suspension of Zn 5 (OH) 8 (Cl) 2 .2H 2 O (15.0 wt. % solids), 22.0 wt. % silica (a 40 wt. % aqueous colloidal suspension of Nalco2329® (75 nm silicon dioxide particles) from Nalco Chemical Co.), 2.0 wt. % poly(vinyl alcohol) (Gohsenol® GH-17 from Nippon Gohsei Co.), and 61.5 wt. % water. (The relative proportion of Zn 5 (OH) 8 (Cl) 2 .2H 2 O to silica is 20/80 and that of (Zn 5 (OH) 8 (Cl) 2 .2H 2 O-silica) particles to PVA is therefore 85/15 by weight).
Element 7
This element was prepared the same as Element 1 except that the coating composition was 14.5 wt. % of an aqueous colloidal suspension of Zn 5 (OH) 8 (Cl) 2 .2H 2 O (15.0 wt. % solids), 22.0 wt. % fumed alumina (40 wt. % alumina in water, Cab-O-Sperse® PG003 from Cabot Corporation), 2.0 wt. % poly(vinyl alcohol) (Gohsenol® GH-17 from Nippon Gohsei Co.), and 61.5 wt. % water. (The relative proportion of Zn 5 (OH) 8 (Cl) 2 .2H 2 O to alumina is 20/80 and that of (Zn 5 (OH) 8 (Cl) 2 .2H 2 O-alumina) particles to PVA is therefore 85/15 by weight)
Comparative Element C-1 (Non-metal 2+ hydroxide salt)
This element was prepared the same as Element 1 except that the coating composition was 34.0 wt. % of silica (a 40 wt. % aqueous colloidal suspension of Nalco2329® (75 nm silicon dioxide particles) from Nalco Chemical Co.), 2.4 wt. % poly(vinyl alcohol), (Gohsenol(t GH-23 from Nippon Gohsei Co.), and 63.6 wt. % water. (The relative proportions of silica to PVA are 85/15).
Comparative Element C-2 (Non-metal 2+ hydroxide salt)
This element was prepared the same as Element 1 except that the coating composition was 34.0 wt. % of a fumed alumina solution (40 wt. % alumina in water, Cab-O-Sperse® PG003 from Cabot Corporation), 2.4 wt. % poly(vinyl alcohol), (Gohsenol® GH-23 from Nippon Gohsei Co.), and 63.6 wt. % water. (The relative proportions of alumina to PVA are 85/15).
Printing and Dye Stability Testing
The above elements were printed using a Lexmark Z51 ink jet printer and a cyan inkjet ink, prepared using a standard formulation with a copper phthalocyanine dye (Clariant Direct Turquoise Blue FRL-SF), and a magenta ink, prepared using a standard formulation with Dye 6 from U.S. Pat. No. 6,001,161. The red channel density (cyan) patches and green channel density (magenta) patches at D-max (the highest density setting) were read using an X-Rite® 820 densitometer. The printed elements were then subjected to 1 day exposure to a nitrogen flow containing 5 ppm ozone, in the dark. The density of each patch was read after the exposure test using an X-Rite® 820 densitometer. The % dye retention was calculated as the ratio of the density after the exposure test to the density before the exposure test. The results for cyan and magenta D-max are reported in Table 2.
TABLE 2
% dye
% dye retention
retention
Element
Material
magenta D-max
cyan D-max
C-1
SiO 2
14
85
C-2
A1 2 O 3
25
93
1
Zn 5 (OH) 8 (CH 3 COO) 2 .2H 2 O
100
100
2
Zn 5 (OH) 8 (Cl) 2 .2H 2 O
42
81
3
Zn 5 (OH) 8 (NO 3 ) 2 .2H 2 O
100
100
4
Zn 5 (OH) 8 (CH 3 COO) 2 .2H 2 O/
45
73
silica
5
Zn 5 (OH) 8 (CH 3 COO) 2 .2H 2 O/
33
73
alumina
6
Zn 5 (OH) 8 (Cl) 2 .2H 2 O/
68
92
silica
7
Zn 5 (OH) 8 (Cl) 2 .2H 2 O/
10
37
alumina
The above results show that the elements of the invention had better dye retention than the control elements.
Although the invention has been described in detail with reference to certain preferred embodiments for the purpose of illustration, it is to be understood that variations and modifications can be made by those skilled in the art without departing from the spirit and scope of the invention.
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An ink jet recording element including a support having thereon an image-receiving layer, the ink jet recording element containing a metal hydroxide salt, (M 2+ )(OH) a (A p − ) b .xH 2 O; wherein: M 2+ is at least one metal ion having a 2+ oxidation state; A is an organic or inorganic anion; p is 1 or 2; and x is equal to or greater than 0; and a and b comprise rational numbers as follows: 0<a<2 and 0<b<2 so that the charge of M 2+ is balanced.
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TECHNICAL FIELD
[0001] The present disclosure relates to systems, apparatus, and methods relating to tool string braking in a downhole drilling environment.
BACKGROUND
[0002] Where downhole tools are used to accomplish stationary tasks (e.g., well-logging or well-completion tasks) via suspension lines (e.g., wirelines or slicklines) in a wellbore, the depth of the suspended tool string is of considerable importance. For example, in well-logging processes, it is often necessary to take corresponding measurements over multiple runs at the same depth position within the wellbore. Additionally, logs from different wellbores may be depth-matched for comparison. Thus, errors in depth measurement of the tool string are detrimental to data interpretation. Moreover, performing completion processes at the wrong depth can result in excessive fluid production in the wellbore and/or entirely bypassing a particular zone of interest in the wellbore.
[0003] To locate the tool string in a substantially vertical wellbore, one conventional process is to initially drop the tool string below the intended depth and subsequently pull the tool string up to the target depth by a winch, so that the cable is held in tension. Yet, when the winch is stopped at the target depth, the tool string continues to move on the suspension line upward out of the wellbore. This phenomenon is known as “creep.” Failure to account for creep causes downhole tool operations to be conducted at an incorrect depth.
DESCRIPTION OF DRAWINGS
[0004] FIG. 1 is a schematic diagram of a tool conveyance system for use in a downhole environment of a wellbore.
[0005] FIG. 2 is a side view of a tool string for a downhole tool conveyance system.
[0006] FIG. 3A is a cross-sectional side view of the braking apparatus of FIG. 2 with the spring casing in a lowered position.
[0007] FIG. 3B is an enlarged view of a side slot of the braking apparatus of FIG. 2 .
[0008] FIG. 3C is a cross-sectional side view of the braking apparatus of FIG. 2 with the spring casing in a raised position.
DETAILED DESCRIPTION
[0009] FIG. 1 is schematic diagram of an exemplary tool conveyance system 10 for use in a downhole environment of a wellbore 12 . The tool conveyance system 10 includes a tool string 14 , a suspension line 15 , and a hoisting mechanism 16 . As shown, the tool string 14 is supported in the wellbore 12 by the suspension line 15 . In some examples, the suspension line 15 is an electrically conductive wireline that physically supports the tool string 14 and conveys electricity to the tool string. In other examples, however, the suspension line 15 is non-electrically conductive slickline that only provides physical support to the tool string 14 . The hoisting mechanism 16 provides motive force for moving the suspension line 15 , and thus the tool string 14 , through the wellbore 12 . In this example, the hoisting mechanism 16 is anchored to a ground surface 17 at the head of the wellbore 12 . However, other implementations may employ the hoisting mechanism 16 on a drilling rig, offshore platform, heavy-duty vehicle, etc. The hoisting mechanism 16 may include a motorized winch, crank, pulley or any other device suitable for anchoring and/or providing motive force to the suspension line 15 .
[0010] The tool string 14 includes a cable head 18 , a downhole tool 20 , and a braking apparatus 100 . The cable head 18 securely couples the tool string 14 to the suspension line 15 . If the suspension line 15 is an electrical wireline, the cable head provides an electrical connection between the wireline and the downhole tool 20 . The downhole tool 20 may include one or more various types of downhole tools. The downhole tool(s) can be designed to accomplish well-logging tasks, such as measuring rock and fluid properties in a new wellbore and/or measuring pressures or flow rates in the wellbore, The downhole tool(s) can also be designed to accomplish well-completion tasks, such as perforating the wellbore casing to allow the inflow of gas and liquids. Downhole tools suitable for various other well-logging and/or well-completion operations can also be used. In some examples, the downhole tool 20 can include at least one well-logging tool and at least one well-completion tool.
[0011] In the foregoing description of the tool conveyance system 10 , various items of conventional equipment may have been omitted to simplify the description. However, those skilled in the art will realize that such conventional equipment can be employed as desired. Those skilled in the art will further appreciate that various components described are recited as illustrative for contextual purposes and do not limit the scope of this disclosure. Further, while the tool conveyance system 10 is shown in an arrangement that facilitates deployment in a substantially vertical or straight wellbore, it will be appreciated that arrangements are also contemplated in a horizontal or highly deviated wellbore environment where the tool string may experience involuntary movement and therefore are within the scope of the present disclosure. The tool conveyance system 10 and other arrangements may also be used in wellbores drilled at an angle greater than 90 degrees to inhibit tool string movement due to gravitational forces.
[0012] FIG. 2 is a side view of a tool string 14 that can, for example, be incorporated in the tool conveyance system 10 depicted in FIG. 1 . In this example, the downhole tool 20 includes a casing collar locator 20 a and a perforating gun 20 b . The casing collar locator 20 a is an electrical well-logging tool used for depth correlation. The perforating gun 20 b is a well-completion tool designed to create perforations (e.g., punched holes) in the casing of the wellbore, allowing oil and/or gas to flow through the casing into the wellbore.
[0013] While the casing collar locator 20 a and the perforating gun 20 b are common downhole tools, their illustration in this example is not intended to be limiting. As discussed above, any suitable downhole tools are embraced by the present disclosure. Further, while in this example, the braking apparatus 100 is located between the casing collar locator 20 a and the perforating gun 20 b , other arrangements are also contemplated. For example, the braking apparatus 100 can be located at the leading or trailing end of the tool string 14 without departing from the scope of this disclosure.
[0014] Referring next to FIGS. 3A-3C , the braking apparatus 100 includes a housing 102 , an actuating mechanism 104 , and a pair of braking arms 106 . As shown, components of the braking apparatus 100 are arranged about a central longitudinal axis 101 . The housing 102 is a hollow tubular body having an external cylindrical side wall outlining an internal cavity. The actuating mechanism 104 includes a wedge member 108 located at the floor 109 of the housing 102 . As shown, the wedge member 108 includes a cylindrical pedestal 110 projecting to a frustoconical tip 112 defined by a sloping outer conical surface 114 .
[0015] The actuating mechanism 104 further includes a push-pull device 116 coupled to the housing 102 . The push-pull device 116 includes a biasing member casing 118 to house a biasing member (further discussed below) and a linkage member 120 attached to the upper end 119 of the biasing member casing. The linkage member 120 is connectable directly to the suspension line 120 or indirectly via other tool string elements to the suspension line. Similar to the housing 102 , the biasing member casing 118 is a hollow tubular body having a cylindrical side wall outlining an internal cavity. A guide rod 122 extends through the internal cavity of the biasing member casing 118 and through the floor 121 of the biasing member casing to reach the frustoconical tip 112 of the wedge member 108 . The distal end of the guide rod is attached to the tip 112 of the wedge member 108 . A biasing member 124 is disposed coaxially about the guide rod 122 . The biasing member 124 urges the biasing member casing 118 downward towards the wedge member 108 . The biasing member 124 is biasing to provide a downward biasing force at least as great as the weight of the tool string. In this example, the biasing member is an axial coil spring, in which the context of the casing 118 may alternatively be referred to as a spring casing 118 ; However, other types of biasing members (and corresponding casing for the biasing member) may also be employed as an alternative or supplementing biasing member (e.g., a disk spring, a resilient sleeve, and/or a compressible gas or fluid).
[0016] The linkage member 120 is coupled, directly or indirectly, to the suspension line 15 . In either case, the coupling between the linkage member 120 and the suspension line 15 is such that at least a portion of the pulling force imparted on the suspension line by the hoisting mechanism 16 is conveyed to the linkage member 120 . So, when the hoisting mechanism 16 exerts a pulling force on the suspension line 15 , the spring casing 118 is pulled (e.g., with substantially equal pulling force) via its attachment to the linkage member 120 . When the pulling force on the linkage member 120 exceeds the biasing force of the biasing member 124 , the biasing member collapses, allowing the spring casing 118 to be moved upward in the housing 102 , away from the wedge member 108 . When the pulling force is reduced, or ceases, the biasing member 124 urges the spring casing back downward towards the wedge member 108 .
[0017] The braking arms 106 are pivotally coupled to the floor 121 of the spring casing 118 and extend downward towards the wedge member 108 . As shown in FIG. 3A , when the spring casing 118 is in the lowered position (e.g., when the pulling force exerted on the linkage member 120 is less than the biasing force of the biasing member 124 ), the braking arms 106 bear against the sloping conical surface 114 of the wedge member 108 , forcing the braking arms 106 to pivot radially outward. In this position, the braking arms 106 protrude through arm-bay openings 126 formed radially along a lower portion of the housing 102 (see FIG. 3B ). With the braking arms 106 deployed through the arm-bay openings 126 , brake pads 128 formed on the distal ends of the braking arms 106 are designed to engage a casing wall of the wellbore 12 . Friction between the casing of the wellbore 12 and the brake pads 128 produce a braking force to hold the tool string 14 in place. Thus, the hoisting mechanism 16 is stopped when it is determined that the tool string 14 is at the target depth within the wellbore 12 , thereby eliminating the pulling force, the braking force from the deployed braking arms 106 counteracts the creep phenomenon.
[0018] FIG. 3C shows the spring casing 118 in a raised position (e.g., when the pulling force on the linkage member 120 is greater than the biasing force of the biasing member 124 ). In the raised position, the braking arms 106 pivot radially inward toward the central longitudinal axis 101 of the braking apparatus 100 . The inward pivoting motion of the braking arms 106 pulls the brake pads 128 away from the wellbore casing, lessening the friction braking force and allowing the pulling force of the hoisting mechanism 16 to move the tool string 14 upward through the wellbore 12 .
[0019] In some embodiments, to reduce frictional drag as the tool string 14 is being lowered through the wellbore 12 , an electrical or mechanical device can be employed to hold the braking arms 106 in a retracted state until the lowest tool depth is reached. For example, a band can be used to hold the arms closed until a small charge is set off that would break a link in the band. The braking arms would then expand to the point allowed by the mechanism. As yet another example, a small motor could be used to hold the braking arms in place while the tool string is being lowered through the wellbore.
[0020] A number of embodiments of the invention have been described. Nevertheless, it will be understood that various additions and modifications may be made without departing from the spirit and scope of the inventions.
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A braking apparatus for a tool string positionable in a wellbore and a method of braking a tool string in a wellbore is disclosed. The braking apparatus includes: a tubular housing having at least one radial arm-bay opening; an actuating mechanism including: a wedge member mounted in an internal cavity of the housing; an axial guide rod coupled at one end to the wedge member; and a push-pull device. The push pull device includes: a biasing member casing through which the guide rod extends to contact the wedge member, a biasing member; and at least one braking arm pivotably mounted to a lower portion of the biasing member casing, wherein when the biasing member casing of the push-pull device in in a lowered position, the braking arm bears on a sloped surface of the wedge member to project the braking arm into contact with a wellbore wall.
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This disclosure is based upon, and claims priority from French Application No. 99/02125, filed on Feb. 19, 1999 and International Application No. PCT/FR00/00285, filed Feb. 7, 2000, which was published on Aug. 24, 2000 in a language other than English, the contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
The invention relates to a method for producing scratchable blocks on a support and a support incorporating such a block.
Scratchable blocks means any pattern printed on a support for the purpose of being removed simply by scratching with a nail or any object of sufficient hardness, the objective generally being to discover an inscription or a design printed underneath the said block.
Up to the present time use has been made of screen printing or heat transfer printing technologies for producing the scratchable blocks.
In both cases, the material used for the printing has good covering power and sufficient adhesion with respect to the support in order not to come off by itself, but insufficient adhesion to be able to resist scratching.
However, such technologies are not particularly well suited to mass production because of their low speed of deposition and/or the complexity of use.
However, there are greater and greater moves towards the use en masse of such scratchable blocks, naturally in the field already known, which is the field of games such as lotteries and disposable cards.
The applicant is also moving towards other uses, for example all applications involving portable supports such as smart cards (banking smart cards and/or electronic purses and/or telephone smart cards).
In such applications, the scratchable block could be used for covering for example a number useful to the user.
The existing printing technologies for depositing scratchable layers or scratchable blocks of materials on supports made of paper pulp such as paper or cardboard which exist today, that is to say heat transfer or screen printing methods, are not at all adapted to the problem of productivity, as stated, because of their low speed of deposition and/or their complexity of use.
In addition, the production of more elaborate scratchable blocks, that is to say for example multicolour or multishape, is here also a restrictive element in the technologies currently being used.
SUMMARY OF THE INVENTION
The object of the invention is a method for resolving the problems of speed and dynamic change of size, shape and colour of the scratchable block in the context of an industrial or other use.
The object of the invention is therefore more particularly a method for producing scratchable blocks on a support, principally characterised in that it includes the use of a technique of ink-jet printing.
According to another characteristic of the invention, the ink used is an ink of the phase change type (hot melt, in English terminology).
According to another characteristic, the inks used contain oligomers and polyamides.
According to another characteristic of the invention, the support on which deposits of scratchable blocks can be effected may be a plastic support such as an integrated circuit card (smart card) whatever the standard of the card and whatever the application.
The ink used contains the ester of a hydrogenated abietic acid (a tackifier) and a plasticiser. In the case of printing on a plastic support, the amount of hydrogenated abietic acid ester in the composition of the ink amounts to 16.5% to 27% and that of the plasticiser will respectively be 15% to 4.5%.
According to another characteristic of the invention, the support can be made from rigid paper pulp (cardboard) or flexible paper pulp (paper).
According to another characteristic of the invention, the printing by ink jet is obtained by means of one or more print heads controlled according to the shape, size and/or colour of the block to be produced.
According to another characteristic, the print heads used are of the piezoelectric type.
Another object of the invention is a support containing information or a graphic on one face and a scratchable block masking the said information or graphic. It is characterised in that the said scratchable block is composed of juxtaposed and/or superimposed dots of material.
BRIEF DESCRIPTION OF THE DRAWINGS
Other particularities and advantages of the invention will emerge from a reading of the description made below which is given by way of illustrative and non-limitative examples with regard to the drawings, in which:
FIGS. 1 a and 1 b illustrate an item of equipment for implementing the method according to the invention, and
FIG. 2 illustrates the result obtained on a support such as a smart card to the ISO format.
DETAILED DESCRIPTION
The method of the invention can be implemented in a different manner by the use of one or more ink-jet print heads according to the application. Thus one or more heads will be used according to the shape which it is desired to obtain for the scratchable block, possibly sized with respect to the size of the head and also according to the fact that it is wished to obtain blocks with a single colour or several colours.
One advantage of the present invention is that the print heads can be positioned in the existing production lines for manufacturing scratchable blocks, replacing the current solutions.
It is therefore possible to have one or more ink-jet heads for covering, through their design or their mechanical positioning, the width of the useful surface to be printed. One or more inks in the same or several colours will be ejected by the ink-jet heads when the object to be processed passes, which can therefore be of the paper, plastic or other type.
The inks which can be used for these applications can for example be of the phase change type (hot melt, in English terminology), which have the advantage of solidifying in contact with the printed surface and which are compatible with a wide variety of supports without any particular processing. These are waxes.
The main material which is used most frequently for phase-change ink-jet applications is wax.
This is because the characteristics of this material lend themselves very well to the cycles of rise and cooling in temperature necessary for this type of technology. The main uses of this type of ink are generally oriented for paper or porous support applications which allow good attachment of the wax-based ink in the fibres of the support.
However, in the context of this invention, the wax has the main defect of not being sufficiently adherent to plastics materials, which gives rise to insufficient resistance to abrasion in the context of this application.
For this purpose, the method described in the invention uses phase-change inks which include oligomers and polyamides. This formulation, used by certain ink manufacturers, improves the adhesion on plastics supports and facilitates the achievement of specific colours necessary for this application.
At the present time, products based on this technology are available from companies such as Data Product, Brother, Polaroid, Markem and Tektronic. These products are generally intended for the printing of supports of the paper or cardboard type.
The ink formulations used by the different manufacturers are very similar and it is possible for example to cite as a reference the Color Stix inks from Tektronic can be summarised in the following way:
monoamide 47%
Tetra Amide 21.5%
Agent for making sticky “Tackifier” 27%
Plasticising agent “Plasticiser” 4.5%
The product for making sticky is an adhesion agent for ink (in English tackifier, which corresponds to a hydrogenated abietic acid ester).
Phase-change inks generally have a softening temperature of around 90° C. and physical characteristics compatible with piezoelectric inkjet technology as from 130° C.
In the context of the invention, the use of the inks generally used for paper applications does not make it possible to have sufficient adhesion on a plastic support for the application in question. In order to improve the adhesion of the ink, changes to formulations are necessary.
In order not to increase the tackifiers in the inks too much, the applicant has preferred to reduce the plasticisers, which are generally of the polymer type, better suited to plastic applications.
One example of a plasticiser used in the context of the invention is di-isonomyl phthalate.
The proportions of tackifier and plasticiser in the composition of the ink can be:
tackifier: 16.5% to 27%
plasticiser: 4.5% (with 27% tackifier) to 15% (with 16.5% tackifier).
The thickness of ink deposited varies according to the printing resolution, the formulation of the ink and the temperature, and the nature of the substrate when the drop arrives on the support.
In the context of the invention, the thickness deposited varies between 8 and 20 μm according to the parameters mentioned above.
An item of equipment E allowing the ink-jet printing of scratchable blocks according to the method of the invention has been shown schematically in FIGS. 1 a and 1 b.
This equipment will include for example a print head in controlled by an electronic control 2 which will include a control program PG adapted to the shape and size of the pattern which it is wished to produce.
There is nothing original per se in the electronic control 2 , and the existing controls for printing machines used in paper printers can be used for example for controlling this print head. Naturally, the parameters concerning the linear speed of movement of the head, the output d of the ink which flows in the nozzles in the head and the program concerning the pattern to be produced in one pass or several passes of the head over the support, are entered in the memory of the print head control program.
The print head is supplied, with ink by a heated reservoir 3 , because of the use of phase-change ink based on temperature variation, in a manner which is also conventional. The reservoir bears the reference 3 in the figures.
The ink-jet heads in, and more particularly the heads based on piezoelectric technology, make it possible to achieve linear printing speeds of around 1 to 2 meters per second, which very greatly exceeds, in terms of rate, what current technologies are capable of achieving.
Another very important advantage of the present invention is that the method makes it possible to produce printings of personalised scratchable blocks because of the addressing capabilities of ink-jet heads.
This is because, according to the required application and resolution, it is possible to use several ink-jet heads. Each head will have a specific colour in order to produce different graphical effects at high speed and which can also be different from one support to another by changing parameter during printing. This change in parameter can be effected by means of an input/output peripheral, connected to the control electronics 2 , referenced 4 in the diagram in FIG. 1 b.
FIG. 2 illustrates a support 1 on which a scratchable block P has been printed in accordance with the method of the invention. This block P has been placed in a printing area Z which is defined, with respect to the borders of the card for example, in the program which controls the print head.
The shape of the block produced and the output of ink for obtaining the required thickness e of the ink which is deposited are also defined in this program.
FIG. 2 illustrates an example embodiment on a plastic support S such as a smart card to the ISO format. As stated before, this support can be a paper or cardboard support produced according to the method of the invention. Naturally, the ink can be replaced by a material and then a jet of material in the broad sense will be spoken of.
The invention relates particularly to the use of material-jet or ink-jet techniques in which it is possible to actuate or control unitarily each jet of one drop or blocks of n simultaneous jets each of one drop.
More precisely, the support contains information or a graphic on one face and a scratchable block masking the said information or graphic. The scratchable block is composed of juxtaposed and/or superimposed dots of material. These dots result from the impact of drops of material, notably drops of ink sprayed by material jet in general or ink jet onto the support.
The dots have a resolution greater than 100 dpi. Preferably the resolution is between 100 and 600 dpi.
When the colour effect offered by the technology of the invention is used, it is possible to obtain a block containing dots of different colours.
Advantageously, the coloured dots can form a decorative pattern or information or a security element such as guilloches for increasing the interference with or camouflage of the masked information.
The security pattern can be regular or random, visible or not from the outside. It can be in the same colour as the information or graphic placed on the support so as to merge with it. The pattern can be directly in contact with the information or graphic or be substantially at the same level. It can comprise at least one layer of dots of material or ink on top with an even colour or otherwise.
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A method for producing blocks on a support that are designed to be removed by scratching. An ink jet printing technique is used to produce the blocks. The ink used is of the type with phase change. The method can be used to form a support containing an information or a graphic design on its surface and a scratchable block masking the information or graphic design. The scratchable block consists of juxtaposed and/or superposed dots of material. The method is particularly applicable to smart cards.
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FIELD OF THE INVENTION
This invention relates to vehicles, and will have application to recreational type vehicles such as a lightweight pop-up type camper.
BACKGROUND OF THE INVENTION
Towable campers have long been popular vheicles for the outdoor recreationalist. In recent years, pop-up campers have become very popular in that they allow for adequate storage of gear and accessories while maintaining an efficient aerodynamic profile during road travel. A main drawback to such campers is their weight which due to mechanical lifts and other parts is so increased that many underpowered vehicles are incapable of towing the camper. Often a camping enthusiast has to purchse a smaller camper than is actually needed due to the limited towing ability of the family automobile. Other drawbacks of prior campers are limited interior access and limited access to the stored LP gas bottles.
SUMMARY OF THE INVENTION
The vehicle of this invention is of a monocoque, or unibody, construction. The roof is preferably formed of a single sheet of material which is of a lightweight construction. The camper side walls are formed of lightweight polyurethane panels which are connected to the vehicle frame to form a lighter, more durable camper than was previously produced.
The vehicle also includes an improved access door to its LP gas bottles, and further includes a vertically pivotal side access door which converts into a step and allows the vehicle to retains its sleek aerodynamic appearance during road travel.
Accordingly, it is an object of this invention to provide for a lightweight towable camper which may be towed by more automotive vehicles than a similar size camper of conventional construction.
Another object of this invention is to provide for a towable camper which is durable and dent resistant.
Another object of this invention is to provide for a pop-up camper which efficiently seals the interior of the camper against the elements.
Still another object of this invention is to provide a camper door which allows efficient access to the camper interior while maintaining a sleek aerodynamic look during periods of road travel.
Other objects of this invention will become readily apparent upon a reading of the following description.
BRIEF DESCRIPTION OF THE DRAWINGS
A preferred embodiment of the invention has been depicted for illustrative purposes wherein:
FIG. 1 is a perspective view of the camper of this invention in its travel position;
FIG. 2 is a side elevation view of the camper in its travel position.
FIG. 3 is a rear elevation view of the camper in its travel position.
FIG. 4 is a front elevation view taken of the camper in its travel position.
FIG. 5 is a sectional view taken along line 5--5 of FIG. 1.
FIG. 6 is a perspective view of the side access door mechanism.
FIG. 7 is a vertical sectional view of the side door in the closed position as seen along line 7--7 of FIG. 2.
FIGS. 8-10 are sequential views of the side door shown in vertical section, which illustrate the movement of the door panel and mechanism from its closed position to its fully open position.
FIG. 11 is a fragmentary front perspective view of the camper showing the front access door being opened with portions of the door cut away for illustrative purposes.
FIGS. 12-14 are sequential views of the front access door shown in side elevation which illustrate movement of the door from its closed position to its fully open position.
FIG. 15 is a sectional view taken along lines 15--15 of FIG. 6.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The preferred embodiment herein described is not intended to be exhaustive or to limit the invention to the precise form disclosed. It is chosen and described to explain the principles of the invention and its application and practical use to enable others skilled in the art to utilize the invention.
Referring now to the drawings, and in particular to FIGS. 1-5, reference numeral 10 generally designates a towable vehicle. Vehicle 10 is illustrated as a towable camper which includes a top or roof section 12 which may be placed in lowered and raised positions during travel and camping. The system for raising and lowering roof 12 is well known in the art and is not shown in the drawings and will not be described in this description.
Vehicle 10 is shown in cross-section in FIG. 5, and includes a chassis 14 having spaced T-beam members. Other conventionally available chassis may be utilized. Vehicle 10 also includes a floor 16, with vertical frame members 18 secured to and extending upwardly of the floor to cooperate with a lift system (not shown) in supporting roof section 12. A conventional type hitch 22 allows connection to a towing vehicle (not shown) and wheels 24 facilitate transport of vehicle 10 from camp site to camp site.
Camper 10 further includes side walls 26 and front and rear walls 28 and 30. Side walls 26 and end walls 28, 30 are preferably of a monocoque construction which is known in the vehicle building art, particularly among commercial automobile manufacturers. Each wall 26, 28, 30 is preferably formed of an elastomeric skin (usually urethane with chopped glass formed by the well-known RIM process) which sandwiches a lightweight insulative urethane foam and is connected to frame members 18 to form enclosed living quarters 32. Roof 12 is also formed of a monocoque construction similar to walls 26-30.
Access to living quarters 32 is gained through a door 34 located along one side wall 26. Door 34 includes a frame 36, shown in detail in FIG. 6. Frame 36 includes spaced support bracketss 38 (also shown) which are secuted to chassis 14 alternating to floor 16 by welding or other suitable means. A door frame 42 which supports a skin 40 of the monocoque construction like walls 26-30 is pivotally connected to brackets 38 through peripheral supports or studs 41 connected to arms 43 which are pivotally fastened to the brackets through bolts 44 and spacer bushings 46. Door frame 42 includes spaced vertical outer frame members 48, 49 and spaced horizontal outer frame members 50, 51 which form a substantially rectangular shaped door frame as shown in the drawings. Door frame 42 further includes an inner horizontal frame member 52 which extends between frame members 48, 49 above arms 43 and inner vertical frame members 54, 55 which extend between frame members 52 and 50. A horizontal frame member 56 may be extended between frame member 54, 55 if desired to provide additional support and to allow a door lock member 59 to be recessed. It should be noted that, to insure efficient operation of door 34, door frame 42 should be slidable relative to supports or studs 41. As shown in FIG. 15, slidable operation is achieved by a U-shaped connector rod 57 connected to vertical frame members 48, 49 and through bearing block 61 to studs or supports 41.
Lock member 59 is formed of latch pins 58 connected by cables 60 to a pivotal latch 62, and is secured to door frame 42 as shown. Each pin 58 is preferably biased by an internal spring (not shown) to hold the pin in a normally exended lock position shown in FIGS. 6-7. Slats 64 extend between and are connected to brackets 38 to provide additional support for frame 36.
Sequential operation of door 34 is shown in FIGS. 7-10. In FIG. 7, the door 34 is shown in teh closed position with pins 58 extending into bores 66 in camper vertical frame members 18. To open door 34, a user first pulls latch 62 in the direction of arrow 68 (FIG. 8) which causes cables 60 to draw pins 58 inwardly out of frame bores 66. Door frame 42 is then allowed to slide downwardly in the direction of arrow 70 until frame member 52 contacts pivot arms 43 to halt downward movement of the door frame. At this point, door frame 42 is lowered further by pivotal movement along an axis defined by bolts 44 in the direction of arrow 72 (FIG. 9). Finally, FIG. 10 illustrates the fully opened position of door 34, with horizontal frame member 51 supported in the substantially horizontal position shown by contact with chassis 14. In this position (FIG. 10), access is gained to living quarters 32 thrugh an opening in side wall 26 with the upper portion 74 of inner door skin 40 being exposed and serving as a step into the living quarters. A reinforcement member 76 of suitable material may be secured to inner door skin portion 74 to protect its appearche and structural integrity when in use as a step. Door 34 is closed by simply lifting up on latch 62 and/or frame member 50 to pivot the door into its closed position with latch 62 turned to retract pins 58 and then releasing latch 62 to allow pins 58 to extend into frame bores 66.
FIGS. 11-14 depict the front access panel door 78 of camper 10 which allows access to the front of the camper where LP gas containers 80 and other supplies may be stored between front end wall 28 and interior divider wall 82. Access panel 78 is pivotally connected by brackets 84 and bolts 86 to arms 88. Guide members 90 extends outwardly from and are secuted to interior wall 82. One guide member 90 is provided for each arm 88 and is preferably of the C-shaped construction shown with opposed flanges 92 which slidably retain arm 88. A spring 94 is connected between guide member 90 and arm 88 at a pin 96 to bias movement of access panel 78 from its opened (FIG. 14) into its closed (FIG. 11) positions. Spring 94 can also serve as a stop to limit the extent of opening movement of panel 78.
To open access panel 78 to expose gas containers 80 for removal, a user first unlocks the panel by twisting T-handle 98 to withdraw latch pins 100 from frame bores 102. It is here understood that many types of security devices may be used to latch access panel 78 in the closed position. The latch chosen is well known in the art and is depicted for illustrative purposes only. After unlocking, the user pulls handle 98 to open panel 78 by the sliding movement of arms 88 in the direction of arrow 106 (FIG. 13) within guide members 90. By pivoting access panel 78 in the direction of arrow 104 (FIGS. 11 and 13) about bolts 86 in plates 84, the panel may reach its fully opened position (FIG. 14) to allow removal of containers 80 or other articles stored therein. Panel 78 is then returned to its closed position of FIG. 12 and locked in this position by pins 100 extending into frame bores 102.
It is understood that the above description does not limit the invention to the precise form disclosed, but may be modified within the scope of the following claims.
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A towable vehicle which includes a pivoting access door. The access door is connected to the vehicle frame for pivotal movement between a vertical closed position, and a horizontal, open position wherein the door is supported by the vehicle frame and acts as a step. The vehicle may also include a storage access door which slides outwardly of the vehicle then pivots along an axial arm to provide access to a storage compartment.
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This is a continuation of copending application Ser. No. 615,837, filed May 31, 1984.
BACKGROUND OF THE INVENTION
The present invention relates to a receiver or chucking device for the interchangeable attachment of a work-contacting probe pin or probe-pin combination to the probe head of a coordinate-measuring instrument. Such devices are intended to permit the fastest and easiest possible chucking of the probepin combination necessary for a specific measurement task.
Until now, it has been customary, in a manual operation, to screw or clamp the probe pin into the probe head. However, this manual operation is disadvantageous in the case of large-scale automatically controlled measurement processes, since it requires an operator whose sole purpose is to replace probe pins at relatively long intervals of time.
A measurement method is known from "American Machinist", October 1982, pages 152-153, in which the measurement machine itself changes the probe, under computer control. However, that reference does not show how to provide a chucking device for fastening the probe to the machine; in any event, this known automatic change method requires calibration of probe pins after each change, thereby slowing the measurement process.
British Patent No. 1,599,751 discloses a receiver for replaceable attachment of a complete probe head to the measuring spindle of a measurement machine. This receiver consists of a three-point support on the measurement spindle, and the feeler head is drawn against the three-point support by means of a clamping lever. The support unequivocally determines the position in space of the probe pins with a high degree of accuracy. But again, in the case of this instrument, replacement of probe heads is effected by an operator, who must actuate the clamping lever. There is also the disadvantage that, as a result of changing the complete probe head, a large number of different electrical connections to the measurement machine must be interrupted.
West German Gebrauchsmuster No. 7,400,071 discloses a probe head wherein a probe pin is removably secured to the probe head by means of several permanent magnets. Here, the magnet attachment serves to protect against collision damage. When the pin falls off, in the case of an excessive load, the pin must be reinserted by hand. This solution is not suitable for effecting an automatic change of the probe pin.
BRIEF STATEMENT OF THE INVENTION
The object of the present invention is to provide a receiver or chuck for the interchangeable attachment of a probe pin or probe-pin combination in such manner as to permit a change that is automatically controlled from the machine.
This object is achieved by providing an electrically operated clamping device which draws the connecting member of a probe pin or probe-pin combination against a support which unequivocally determines its position in the receiver of the probe head.
Actuation of the electromagnetic clamping device can be effected automatically by a computer which controls the path of probe-head movement in the measuring machine and the detection of the measurement value. The computer need merely be so programmed that it brings the probe head of the machine to a magazine, which illustratively is provided at a margin of the measurement region and in which different probe pins or probe-pin combinations are stored; the program causes the clamping device to deposit, in the magazine, probe-pin combinations which are no longer required and/or to pick up a new probe-pin combination. Thus, in a probe-pin change, all manual operations are eliminated.
With sufficiently large dimensioning of the support against which the connecting member is drawn, it is in most cases possible to dispense with calibration of the probe ball after introducing a new probe-pin combination, such calibration being necessary only at longer intervals, i.e., probe-pin calibration is not necessary after each change. As a result, measurement time is saved.
The clamping device may illustratively comprise an electric motor having a self-locking transmission which draws the probe pin against its support. In the simplest case, this transmission consists of a threaded spindle on the axis of the motor, the spindle being engaged to a corresponding mating thread in the connecting member.
However, it is particularly advantageous if the clamping device comprises a permanent magnet and an electromagnet, wherein the field of the electromagnet can be superposed on the field of the permanent magnet. With this embodiment, the number of moving parts in minimized and nevertheless the receiver, as in the case of the embodiment involving a motor with self-locking transmission, does not consume any current during intervals between changes.
The permanent magnet is advisedly displaceable against spring force in the direction toward the support for the probe pin. By means of this spring, a reliable separation of the probe pin from the probe head is assured at all times, so that the danger of "sticking" due to an imperfectly compensated or compensatable residual magnet field is avoided.
It is advisable to install the clamping device in the receiver of the probe head, since then only one clamping device is required for each measuring instrument. However, it is also possible to install the clamping device in the connecting member of the probe pin as long as reliable electric switching of the clamping device is assured by the provision of protruding contacts and of corresponding mating contacts on the involved probe-pin magazine. It is also possible to arrange only the permanent magnet or transmission in the connecting member and to associate the electromagnet or motor with the magazine.
The support of the probe head preferably consists of three cylindrical bodies, and the mating support on the probe-pin side comprises three pairs of balls which nest (via their V-shaped spaces) against the cylindrical bodies. By means of such an arrangement, which is already well known to establish the connection point (Knickstelle) for probe heads, the position of the probe-pin combination relative to the coordinate system of the measuring instrument, is clearly determined within an angle of 120°. In order to assure lack of ambiguity over the entire angular range of 360°, an off-axis groove (or locating pin) can be provided in the support, this groove enables angularly unambiguous reception of an off-axis locating pin (or groove) on the connecting member of the probe-pin combination.
The receiver or chuck of the invention is suitable (a) for switch-type probe heads which produce a pulse-like signal when contact is made and (b) for probe heads of the so-called measuring type which contain measurement-value transmitters which, starting from a zero or reference position, supply a signal proportional to the deflection of the movable probe-head part. Probe heads of the last-mentioned type, such as, for instance, the probe device described in U.S. Pat. No. 3,869,799, as a rule include motorized weight balancing to equalize deflections of the probe chuck after insertion of probe-pin combinations of different weight or weight distribution. With the present invention, it is advisable to provide within the probe chuck a switch which signals the presence of a correctly inserted probe pin and which electrically certifies correct reception of the probe pin, the operation of said switch being an interlock function for controlling automatic weight equalization of the probe head.
The connecting member of the probe-pin combination advantageously consists of two parts which are relatively rotatable and can be locked in position, so that the probe-pin combination can be rotated into any desired angular position, as dictated by the workpiece and the specific measurement task.
DETAILED DESCRIPTION
The invention will be illustratively described for two embodiments, in conjunction with the accompanying drawings, in which:
FIG. 1a is a first longitudinal sectional view through a first embodiment, taken along the line I--I of FIG. 3;
FIG. 1b is a fragmentary detail of one of the three groups of bearings (14/15) of FIGS. 1a and 3;
FIG. 2 is a second longitudinal section through the embodiment of FIG. 1, in a 90°-displaced plane indicated by the line II--II of FIG. 3;
FIG. 3 is a transverse section, taken at line III--III of FIG. 1 and FIG. 2, with the probepin carrier removed;
FIG. 4 is a view similar to FIG. 1, for a second embodiment of the invention; and
FIG. 5 is a perspective view of a magazine adapted to store probe-pin carriers of the embodiment of FIG. 1.
In FIGS. 1 to 3, the receiver or chuck for a probe-pin combination 21 comprises a cylindrical housing 1 having a flange 2 via which housing 1 is mounted to the deflectable part of a probe head (not shown), as for example to the part 1 of the probe head described in U.S. Pat. No. 3,869,799.
An annular ring 3 has threaded engagement to the bore of housing 1, and ring 3 engages one end of a set of cup springs (Belleville washers) 5. This set of springs 5 is preloaded to urge a retaining plate 6 in the direction toward the upper housing wall 8 of the receiver 1.
The housing 9 of a structural unit consisting of an electromagnet 10 and a permanent magnet 11 is secured to plate 6 by means of a screw 7.
As can be noted from FIGS. 1a, 2 and 3, housing 1 has three radial openings 23a, b and c which are covered by a sleeve 22. A bore 24a extends to opening 23a, from the upper end 8 of housing 1. Bore 24a accommodates connecting cable 25 for electromagnet 10, and cable 25 will be understood to be connected to controls of the measurement machine via the probe head (not shown).
At its lower end, the receiving housing 1 includes probe-supporting means comprising three cylindrical bodies 14a, 14b and 14c which are arranged within the wall of the housing and are located 120° apart. The radially oriented arrangement of these cylindrical bodies can be noted from FIG. 3. A ring 16 has referencing engagement to said supporting means via three pairs of circumferentially spaced balls 15a, b, c; as shown in FIG. 1a for the engaged support elements 14a/15a, each pair of balls forms a V-shaped groove for nested location of a cylindrical body 14. In addition a pin 27 carried by housing 1 engages within a local cutout 26 of ring 16, thus unequivocally determining the spatial position of ring 16 relative to receiver 1 (which is connected to the probe head); pin 27 will be understood to assure the unequivocal character of the seating of ring over the entire circular circumference of 360°.
A first or upper circular plate 18 is seated in a counterbore of ring 16, and a flanged second or lower plate 19 is located to the underside of ring 16, being secured to plate 18 by three screws 17. The second plate 19 has a central thread 20 into which the probe-pin combination 21 is removably engaged. Ring 16 is clamped by the two plates 18 and 19 upon the setting of screws 17, thus securely connecting the probe-pin combination 21 to ring 16. By loosening of screws 17, plates 18 and 19 can be rotated with respect to ring 16, thus enabling angular adjustment of a generally asymmetrical probe-pin combination 21.
The plates 18 and 19, the ring 16 and the pairs of balls 15 form the connecting member of the probe-pin combination. Plate 18 is made of steel, so that the connecting member is drawn by the permanent magnet 11 against the cylindrical bodies of the supporting means 14a, b, c. For an automatically controlled probe-pin change, the electromagnet 10 is so energized by direct current as to produce an additional magnetic field of magnitude approximating but directionally opposed to that of permanent magnet 11, so that the net resultant field is substantially zero. In this circumstance, the holding force between magnet 10 and plate 18 disappears, and the spring 5 presses the magnet combination 9 upward until the plate 6 abuts the upper end 8 of the housing. The involved displacement of the structural part 9 develops a gap between plate 18 and the upper end of magnet 11; the axial extent of this gap corresponds to the distance shown in FIGS. 1a and 2 between the plate 6 and the housing cover 8. The connecting member (16-17-18-19), together with the probe-pin combination mounted thereto, then drops out of the supporting means by its own weight, and is stored in one of the holders of the magazine shown in FIG. 5 for example.
Another probe-pin combination provided with a similar connecting member can then be removed from such a magazine when the measurement machine, under the control of a suitable program, moves the receiver 1 (mounted to the probe head) to another magazine location and positions it above the connecting member of the desired probe-pin combination. Removal of the combination from the magazine can be effected, in principle, without actuation of the electromagnet 10, since the connecting member is automatically drawn against its supporting means, upon sufficient approach of the permanent magnet 11, depending upon the weight of the combination. It is advisable, however, to more positively effect removal of the combination from the magazine by also energizing the electromagnet 10 which such polarity that its field reinforces the field of the permanent magnet 11; this assures a dependable take up of the combination, for even larger gap widths between plate 18 and the magnet 11. It will be understood that upon take up of a new combination (with probe-pin) from the magazine, the structural part 9 (with plate 6) is drawn downward against action of spring set 5 and into the axial offset from the upper end 8 of the housing, as shown in FIG. 1a.
A microswitch 13 is shown mounted by two screws 12a, 12b, to the lower edge of the bore of housing 1. This microswitch is actuated by ring 16 as soon as the latter engages the supporting means 14. Automatic weight compensation of the probe head, as described in U.S. Pat. No. 3,869,799, can therefore be initiated by switch 19, the connecting cable for microswitch 19 being shown passing through bore 24b (FIG. 3).
FIG. 4 shows another embodiment of a receiver or chuck for the replaceable attachment of a probe-pin combination. This receiver again consists of a cylindrical housing 101 provided with a flange 102. By means of the flange 102 the receiver can be fastened, for example, to the movable part 3 of the probe head described in U.S. Pat. No. 4,177,568. On the bottom of the housing are three cylindrical bodies 114 which form the supporting means for a connecting member comprising a ring 116, pairs of balls 115, and plates 118 and 119. A probe-pin combination 121 (not fully shown) can be securely engaged to plate 119 via thread 120. As in the previous embodiment, the plates 118 and 119 are connected to each other by three screws 117 and, after the loosening of said screws, plates 118-119 can be rotated with respect to ring 116. In this case also, a pin 127 in the housing 1 serves, in combination with a cutout 126 in ring 116, for the unequivocal orientation of the position of ring 116 with respect to the probe head.
In contrast to the embodiment shown in FIGS. 1 to 3, the connecting member 115-116-117-118-119 of FIG. 4 is drawn against the supporting means 114 not by a permanent magnet but, rather, by a threaded spindle 111, with the aid of an electric motor 109. For this purpose, plate 118 is provided with a concentric mating thread 131 engaged to spindle 111.
The housing of the electric motor 109 has an annular collar 108 and is fastened, by means of three screws 107 and clamp washers which clamp said collar to a support ring 104. Seated in this support ring 104 is a thrust bearing 112 for relieving the shaft 110 of motor 109. A set screw 113 secures the threaded spindle 111 to the motor shaft 110. Support ring 104 and the motor 109 mounted thereto will be seen as a completely assembled unit inserted into housing 101. And the support ring 104 is fixed in housing 101 by three stud bolts 103 having conical ends to locate against the upper flank of a V-shaped annular groove 105, thus pressing the support ring 104 against the locating rim 106 of a counterbore within housing 101. The threaded bores for bolts 103 are covered by a sleeve 122.
Upon a change of the probe-pin combination, motor 109 will be understood to be activated by the program control of the measurement machine, to drive spindle 111 out of engagement with the thread 131 of plate 118. After suitably controlled repositioning of the probe head and reversal of the direction of rotation of motor 109, the motor-driven spindle engages and draws another connecting plate (having a different probe-pin combination) against the supporting means 114. Motor 109 is disconnected by an electronic control system (not shown) when a predetermined torque has been reached, thus determining the force of application of ring 116 and its pairs of balls 115 against the supporting means 114. The thread pitch of spindle 111 is preferably small, so that self-locking occurs, whereby the probe-pin combination remains fastened in the receiver 1 with constant holding force even when the motor is no longer energized.
The isostatic three-point supports (14/15 and 114/115) in the two embodiments of FIGS. 1 to 3 and FIG. 4 determine the position in space of the probe-pin combination relative to the probe head with such a high precision of reproducibility that it is possible to dispense with a separate calibrating process after changes of probe-pin combination. This being the case, the workpiece to be measured can be immediately contacted by a newly mounted probe-pin combination whose geometry (relative to the machine coordinate system) is stored in the computer. This leads to a considerable reduction in measurement time, particularly in measurement jobs which require frequent probe replacement.
The magazine shown in FIG. 5 consists of several holder-plates slidably mounted to a rail 30. Two of these plates, designated 31 and 41, are shown in the drawing. These holder-plates 31 and 41 are adapted to store probe-pin combinations for the holding device shown in FIG. 1a to FIG. 3.
Holder-plates 31 and 41 are provided with fork like recesses 37 and 47, respectively, enabling horizontal movement of the probe-pin combinations to their storing place at plates 31 and 41.
Additional cover plates 33 and 44 are pivotably mounted to holder-plates 37 and 47, the pivot axes being designated 32 and 42. Plates 33 and 44 cover the support side of the connecting member 15-19 of stored probe-pin combinations from dust exposure, thereby preventing a misadjusted attachment of probe-pin 21 and the probe head. The bottom surfaces of cover plates 33 and 44 carry velvet layers 34 and 43. These layers 34 and 43 serve to smoothly clean support members 15a in the course of pivoted displacement of cover plates 33 and 44 about their axes 32 and 42.
Under "normal" conditions, i.e. during the measuring procedure between probe-pin changes, cover plates 33 and 44 are biased into the position shown for plate 33 by a spring (not shown). If a probe-pin is stored in recess 37 of plate 31, its support side also would be covered by velvet layer 34 of plates 33.
A single block 35 (45) is fixedly mounted to the upper side of each plate 33 (44). When the probe head is to be provided with a probe pin stored in the magazine, the probe head is driven by the measuring machine, under computer control, against one of these blocks 35 or 45, thereby causing the involved plate 33 (44) to pivot and thus to be removed from the support end of the involved probe pin. At this juncture, electrical excitation of electromagnet 10 of the receiver or chuck of FIG. 1a is operative to automatically take the probe pin from its holder plate.
A magnet 36 (46) on each of the holder plates 31 (41) enables magnet-retention of the open condition of recesses 37 (47) when one or more of the plates 33 (44) is retracted, so that unobstructed access is available for the measuring machine to establish and store spatial coordinates applicable to the probed recess 37 (or 47). It will be understood that such measurement is necessary when the magazine has just been installed with respect to the measuring machine, so that stored data as to each recess 37 (47) can then be available for subsequent program-controlled storage or pick-up of probe pins.
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The invention concerns a receiver (1) in the probe head of a multiple-coordinate measuring machine in which probe-pin combinations (21) can be replaceably chucked with high precision with respect to their position in space. The receiver contains an isostatic three-point support (14) against which the base (15, 16, 17, 18, 19) of the probe-pin combination is drawn by an electrically operated clamping device. The clamping device is coupled with the control computer of the measuring machine so that a probe change can be effected automatically.
In a preferred embodiment, the clamping device consists of a permanent magnet (11) and of an electromagnet (10) by which the field of the permanent magnet (11) can be selectively counteracted or increased to achieve pick-up and release functions. In another embodiment, a motor-driven screw thread performs the pick-up and release functions, and assures that the picked-up probe will unambiguously be drawn into correct isostatic engagement with the three-point support.
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The present invention relates to an air/fuel mixing arrangement for an internal combustion engine which eliminates the requirement of a conventional carburetor.
BACKGROUND OF THE INVENTION
In conventional internal combustion engines, the air/fuel mixture for combustion is supplied by a carburetor. Such a device is a complex apparatus which requires frequent maintenance attention in order for it to operate properly.
Carburetors also suffer disadvantages in efficiency in providing volumetric throughputs of an air/fuel mixture sufficient to provide adequate power for high speed driving. A number of attempts to improve carburetor efficiency have been made. Generally speaking, these efforts have centered around devices placed between the carburetor and the intake manifold to accomplish additional agitation of the carbureted fuel prior to its passage into the intake manifold. One approach which previously has been taken introduces a rotatable turbulence producing means between the carburetor and the intake manifold. The general configuration of such a device approximates the shape of a fan-type impeller. With such an arrangement, the speed of rotation of the impeller, and hence the amount of turbulence produced, is directly dependent upon the volumetric throughput of the carbureted air/fuel mixture. Thus, at higher speeds and engine power requirements where the volumetric throughput is greater, the speed of rotation of the impeller is greater and, correspondingly, greater turbulence and mixing of the air and fuel are provided. On the other hand, at lower speeds and engine power requirements, the volumetric throughput of the air/fuel mixture is less and, accordingly, the turbulence and mixing of the air/fuel mix produced by the impeller are less. In other words, the rotatable impeller inherently adjusts in speed of rotation whereby it corresponds to engine speed and power requirements.
However, the known impeller device just described suffers an important disadvantage. While it is capable of intimately mixing already vaporized fuel with carbureted air, it is not capable of significantly atomizing liquid fuel droplets by itself. Consequently, the use of such a turbulence producing device heretofore has been restricted to its being combined with a conventional carburetor whereby the efficiency of the latter is improved by agitation of the air/fuel mixture produced by the carburetor.
OBJECTS OF THE INVENTION
The principal object of the present invention is to take advantage of the simplicity and air/fuel mixing characteristics of a turbulence producing device while simultaneously eliminating the need for a costly, complex and inefficient conventional carburetor.
It is a further object of the invention to provide an air/fuel arrangement which is responsive to varying engine speed and power requirements in order to provide a proper air/fuel mixture to the engine.
BRIEF DESCRIPTION OF THE INVENTION
The present invention provides an impeller device housed in a chamber to which air is supplied and from which an air/fuel mixture is withdrawn. The impeller is mounted at the end of a rotatable hollow shaft having its opposite end immersed in a fuel storage container. As the impeller rotates, fuel is drawn through the hollow cylinder and is ejected adjacent the impeller blades in order to be atomized and mixed with air supplied to the chamber. In its passage through the hollow shaft, pressurized air is directed into the flow path in order to initially atomize the fuel prior to its being further atomized by the impeller. Means also are provided to selectively pass fuel directly from the storage container to the intake manifold of the engine so as to provide a rich air/fuel mix when the engine is cold.
The invention now will be described in further detail with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevational view, partially in section, illustrating the arrangement for producing an air/fuel mixture in accordance with the present invention;
FIG. 2 is a sectional view taken along line 2--2 of FIG. 1;
FIG. 3 is a top plan view of an adapter for introducing the air/fuel mixture to the manifold of an internal combustion engine; and
FIG. 4 is a sectional view taken along line 4--4 of FIG. 3.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIGS. 1 and 2, the arrangement for producing an air/fuel mixture will be described.
Fuel is stored in a container 10. A cylindrical column 12 projects through the container from a level below to a location above the container. Although the cylinder 12 is shown as integrally formed in conjunction with the container, it is apparent that they may comprise separate components with suitable seals provided at the locations where the cylinder 12 passes through the bottom and top walls of the container. A chamber 14 is provided at the upper end of cylinder 12. A hollow shaft 16 having a closed upper end is positioned within the cylinder 12 and chamber 14. Shaft 16 is retained in position and allowed to rotate with respect to cylinder 12 by suitable bearings 18 and 20. An impeller 22 is secured to the upper end of shaft 16. The impeller comprises a plurality of radially spaced blades and serves as a rotatable turbulence producing means. A plurality of openings 24 are provided in shaft 16 at radially spaced locations disposed between the intersections of the impeller blades with the shaft. An air intake line 26 is connected to one side of chamber 14. At the area of the connection, suitable vanes 27 are provided to direct air flow past the vanes against the impeller blades. A butterfly valve 28 is provided in line 26 to control the amount of air which is permitted to be introduced into the chamber. On the opposite side of chamber 14 from the intake line 26, a suitable number of additional lines 30 are provided for carrying the air/fuel mixture to the intake manifold of the engine. In the embodiment illustrated, two such lines 30 are employed. Intermediate chamber 14 and container 12, an additional air line 32 is joined to cylinder 12. The rotatable shaft 16 is provided with a plurality of apertures 34 in alignment with line 32 for a reason which will become apparent hereinafter. A pair of fuel lines 36 interconnect the container 10 with the bottom portion of cylinder 12 whereby fuel is fed to the cylinder by gravity. An additional pair of fuel lines 38 are provided to feed fuel from the cylinder 12 to the intake manifold.
Referring now to FIGS. 3 and 4, an adapter 40 is provided to fit over the conventional input manifold of an internal combustion engine (indicated generally by numeral 42 in FIG. 4). The adapter comprises a casting having suitable apertures 44 to permit the adapter to be fastened to the engine. An additional pair of apertures 46 are provided in the central portion of adapter 40. The apertures 46 permit the air/fuel mixture carried by lines 30 to pass to the intake manifold as can be appreciated from FIG. 4. The casting 40 is provided with a passage 48 which intersects the apertures 46. This passage receives a throttle rod. A pair of throttle plates 52 are secured to rod 50 within the respective apertures 46. This arrangement permits the openings to the manifold to be varied in response to rotation of rod 50 about its longitudinal axis. An edge 54 of each plate 52 is turned back at an angle of approximately 35° from the plane of the valve for a reasons to be explained subsequently. The casting 40 also is provided with a pair of L-shaped passages 56 extending from the top surface of the casting to a location within the apertures 46 at a level below that of the plates 52 when the latter extend fully across the apertures. The sides of the casting include still further passages 58 intersecting the passages 56. Passages 58 are adapted to receive conventional needle valves 60 which are operative to control the openings of passages 56. The fuel lines 38 are joined to passages 56 at the upper surface of casting 40. Upstream of passages 56 the lines 38 are provided with constrictions 62, and downstream of the constrictions additional lines 64 are provided. The lines 64 serve as breathers to introduce air to the fuel supplied by lines 38.
The structure of the air/fuel mixing arrangement having been outlined, its manner of operation now will be described.
With the engine cold, as in the starting position, the throttle plates 52 are in the position shown in FIGS. 3 and 4 effectively closing apertures 46. Fuel from container 10 passes through lines 38 to be mixed with air supplied by the breather lines 64 and then supplied to the engine intake manifold via passages 56. This mixture is one having a high fuel-to-air ratio. Consequently, the engine is supplied with a rich mixture to facilitate starting.
As the engine starts and idles, a small vacuum is developed in the manifold which draws additional air through the breather lines 64. Since constrictions 62 are provided in lines 38 upstream of the locations of lines 64, passage of fuel through lines 38 is impeded. Therefore, the manifold's vacuum is not as effective in drawing fuel via lines 38 as it is in drawing additional air from lines 64. As a result, the mixture becomes less rich than during starting. The proper supply of the air/fuel mixture for idling is established by selective adjustment of needle valves 60.
When the engine is accelerated by actuation of the throttle, the throttle rod 50 is rotated about its axis to displace throttle plates 52 from the position shown in FIGS. 3 and 4 thereby opening apertures 46. Simultaneously, the butterfly valve 28 is opened due to a linkage (not shown) with the throttle rod operation. The opening of the air intake line 26 due to movement of valve 28 causes air to be drawn by the manifold's vacuum through line 26 and chamber 14. The vacuum also draws fuel upwardly through the hollow shaft 16. As the fuel passes apertures 34, pressurized air supplied through line 32 atomizes the fuel. The source of pressurized air is not illustrated. However, it is apparent that a number of conventional engine-operated arrangements may be employed to supply pressurized air to line 32. Movement of air through chamber 14 causes the impeller 22 and shaft 16 to rotate. Consequently, as the atomized fuel is discharged from the shaft through apertures 24, the additional turbulence and agitation caused by the blades of impeller 22 further atomizes the fuel. The air/fuel mixture is drawn by the vacuum through lines 30 and the apertures 46 into the manifold.
During the operation just described, the turned back edges 54 of the throttle plates 52 deflect the air flow path through apertures 46 thereby reducing the effect of the vacuum on the lines 38. Consequently, the supply of an air/fuel mixture to the manifold via passages 56 is effectively interrupted until such time as the throttle plates 52 are returned to the positions occupied during idling.
By appropriately relating the opening of the butterfly valve 28 with the opening of throttle plates 52, it is possible to achieve a proper air/fuel mixture for the various operating conditions of the engine.
The turbulence producing means, i.e., the impeller 22, which provides improved mixing of atomized fuel and air, may be constructed from a variety of materials such as nylon. Preferably, the pitch of the impeller blades is between about 10 and 25 degrees but can vary across the blade, as is well known in the fan art. The flow of air through the chamber 14 causes the impeller to turn at an angular speed directly proportional to the volumetric throughput of air. Therefore, the turbulence created by the impeller is also directly proportional to the volumetric throughput.
With impeller devices, in the area of the rotational axis an exceptionally strong suction is created, as compared to the suction created towards the outer portions of the impeller blades. This suction helps to draw fuel from container 10 and contributes to the turbulence within chamber 14.
From the foregoing discussion it is apparent that an appropriate air/fuel mixture can be supplied to an internal combustion engine without the necessity of a conventional carburetor. Such an arrangement is simple, efficient and economical, and it is not subject to the maintenance attention required by carburetor-type fuel supply systems.
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An impeller is secured to one end of a hollow shaft and is positioned within a chamber to which air is supplied. An output line from the chamber is joined with the intake manifold of an engine. The opposite end of the hollow shaft is immersed in fuel. When a vacuum is drawn by the manifold, air flow through the chamber rotates the impeller while fuel is simultaneously drawn through the shaft and discharged into the chamber. The turbulence and agitation of the impeller atomizes the fuel so that an air/fuel mixture is supplied to the manifold through the output line. Pressurized air is applied to the fuel as it rises in the hollow shaft to provide initial fuel atomization.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This is a continuation of PCT application No. PCT/EP2009/063838, entitled “HEADBOX FOR A MACHINE FOR PRODUCING A FIBROUS WEB”, filed Oct. 22, 2009, which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates to a headbox for a machine for producing a fibrous web, in particular a paper or cardboard web from at least one fibrous stock suspension, having a feed apparatus for feeding the at least one fibrous stock suspension, having a perforated distributor pipe plate which is located adjacent downstream and has a multiplicity of channels which are arranged in rows and columns, having an intermediate channel which is located downstream of the latter, extending over the width of the headbox and which has a plurality of means which are spaced apart from one another in width direction of the headbox, for preferably adjustable/controllable dosing of fluid in partial fluid streams into the at least one fibrous stock suspension, wherein the individual means respectively comprises a plurality of dosing channels for the fluid, which respectively have one dosing channel opening and which discharge at different heights and which are connected with a common supply channel; with a downstream turbulence generator having a plurality of flow channels arranged in rows and columns, and with a headbox nozzle comprising a nozzle gap immediately adjacent to the turbulence generator.
[0004] 2. Description of the Related Art
[0005] A headbox of this type is known in the field as “Dilution water headbox” and is known for example from German disclosure documents DE 44 16 898 A1, DE 44 16 899 A1 and DE 44 16 909 A1.
[0006] German disclosure document DE 44 16 898 A1 describes a headbox for a paper machine; including a feed device for the stock suspension comprising a guiding element with a plurality of channels; upstream from a guiding element a mixing chamber with several infeed devices which are distributed over the headbox for a fluid which is to be added to the stock suspension and which differs in its characteristics from the stock suspension; and with a nozzle chamber forming an outlet opening for the stock suspension, located immediately downstream from the guiding element. The feed devices for the fluid which is to be added extend essentially vertically in the mixing chamber and comprise several dosing openings located on top of each other.
[0007] German disclosure document DE 44 16 899 A1 describes a headbox for a paper machine including a feed device for the stock suspension, with a first guiding element comprising a plurality of channels, a second guiding element comprising a plurality of channels, an intermediate mixing chamber, a contiguous nozzle chamber forming an outlet opening for the stock suspension, and several feed lines distributed over the headbox for the fluid which is to be added. The majority of the channels of the guiding elements are positioned and dimensioned so that the outlet opening of the upstream guiding element is not aligned with a confluence into the downstream guiding element. The feed lines for the fluid which is to be added are equipped with dosing openings, the majority of which align respectively with a confluence into the downstream guiding element.
[0008] In addition, German disclosure document DE 44 16 909 A1 describes a headbox for a paper machine with a feed device for the stock suspension, a downstream contiguous guiding element equipped with a plurality of channels, located downstream from there a downstream mixing chamber extending across the width of the headbox with several separation walls distributed across the headbox and extending essentially in flow direction, as well as feed devices for a fluid which is to be added, distributed in cross direction of the headbox and which are equipped with dosing openings, downstream an additional guiding element equipped with a plurality of channels and adjacent to it, one nozzle chamber forming an outlet opening for the stock suspension.
[0009] The feed devices for the fluid which is to be added extend into the mixing chamber and the sectional area which is formed in the mixing chamber by the separation walls begins in the region of the dosing openings from where it extends essentially in flow direction to the second guiding element.
[0010] In the currently known processes for producing a fibrous web, in particular a paper or cardboard web from at least one fibrous stock suspension additional fluids, for example paper chemicals, especially retention agents or dewatering accelerators are added as a rule before and/or after the separator, however prior to the headbox and in any case before or at the latest in the feed apparatus. Separators or sorters, also referred to as screens by the expert, can be in the embodiment for example of a vertical separator or as a machine wire. They serve in cleaning the at least one fibrous stock suspension before it is transported on into the headbox.
[0011] In practical operation it turned out that—viewed in flow direction—areas with strong pressure losses or respectively turbulence fields with strong shear fields follow the known locations for adding the additional fluids. The effect of the additional high molecular or respectively additional polymeric fluids, preferably paper chemicals, in particular retention agents or dewatering accelerators is thereby diminished or can be diminished. In addition, process technologically important reaction times of the mediums cannot be adjusted, or cannot be adjusted to a satisfactory level, especially defined with the known systems.
[0012] It is therefore the objective of the current invention, and what is needed in the art is, to improve a headbox of the type described at the beginning in such a manner, that the aforementioned disadvantages of the current state of the art are significantly, preferably completely eliminated. The intent is for the headbox to facilitate especially an efficient and cost effective addition of the at least one additional fluid into the at least one fibrous stock suspension into which the fluid is to be added. In particular, the trilemma should be solved so that on the one hand in certain areas of the headbox, for example in the turbulence generator turbulent flows are desirable at least to a certain extent for the purpose of intensive blending of the components of the at least one fibrous stock suspension to which the at least one fluid is added. That however, on the other hand in certain other areas of the headbox, for example in the headbox nozzle no further blending and therefore not additional swirling of the components of the at least one fibrous stock suspension to which the at least one fluid is added is desirable, and thirdly, so that the effect of certain high molecular or long-chain components of the fibrous stock suspension are not reduced, particularly through turbulence and thereby caused shear fields.
SUMMARY OF THE INVENTION
[0013] According to the present invention this objective is solved in, and the present invention provides, a headbox of the type described at the beginning in that means for preferably adjustable/controllable dosing of fluid in partial fluid streams into the at least one fibrous suspension is designed also for preferably adjustable/controllable dosing of at least one additional fluid in partial fluid streams into the at least one fibrous suspension, wherein the individual means respectively comprises a plurality of dosing channels for the at least one additional fluid, each having a respective dosing channel opening, discharging at different heights and being connected to a common supply channel.
[0014] The inventive objective is completely solved in this manner.
[0015] The inventive design of the headbox of the type described at the beginning extensively, preferably completely eliminates the aforementioned disadvantages of the current state of the art. Addition of the at least one additional fluid into the at least one fibrous stock suspension to which a fluid is to be added, occurs extremely efficiently and cost effectively in the area of the headbox based on the described design of the means, whereby the headbox alone can also be designed cost effectively and technically simple. Lastly, the inventive design of the headbox provides a satisfactory solution of the described trilemma while providing an as uniform as possible distribution of the at least one additional fluid over “Z” direction, that is in height direction of the headbox. The inventive headbox may moreover be in the embodiment of a single layer headbox and may possess properties which are characterizing for a multi-layer headbox.
[0016] Also at least one separation element which is well known to the expert, in particular a lamella may be provided in the headbox nozzle of the inventive headbox. In the event that several separating elements, in particular lamellas are arranged in the headbox nozzle of the inventive headbox they may have different lengths and possibly different properties such as surface profiles.
[0017] Dosing of the at least one additional fluid into the at least one fibrous stock suspension which is to be provided with a fluid can be adjusted/controlled, at least in areas, in a manner obvious to the expert—in width direction of the headbox, in other words in “Y” direction and/or in height direction of the headbox, in other words in “Z” direction.
[0018] A first preferred design form provides that the dosing channels of the means for preferably adjustable/controllable dosing of fluid in partial fluid streams into the at least one fibrous stock suspension which are connected with the common supply channel discharge through dosing channel openings in the downstream area of the means for the preferably adjustable/controllable dosing and that the dosing channels of the means for preferably adjustable/controllable dosing of the at least one additional fluid in partial fluid streams into the at least one fibrous stock suspension which are connected with the common supply channel discharge through dosing channel openings at least on one side, preferably on both sides of the side area of the means for preferably adjustable/controllable dosing. Therefore, a physically separated, physically independent and uniform dosing of the fluids can occur, with the objective of producing a fibrous web having high quality properties. Depending on the specific application, only one column of flow channels of the turbulence generator, or even two columns of flow channels of the turbulence generator may be supplied with the at least one additional fluid.
[0019] Hereby the dosing channels of the means for preferably adjustable/controllable dosing of the at least one additional fluid in partial fluid streams into the at least one fibrous stock suspension which are connected with the common supply channel discharge preferably through dosing channel openings on at least one side, preferably both sides of the side area of the means for preferably adjustable/controllable dosing, in an angle of 0 to 180°, preferable 45 to 135°, especially approximately 90° to the flow direction of the at least one fibrous stock suspension. Depending on orientation of the dosing channel openings, different intensities of impulses may be introduced into the blending areas, thereby influencing the mixing quality.
[0020] To enable a process technologically sufficient dosing of the at least one additional fluid and to provide the precondition for a sufficiently large operational window for the headbox, the dosing channel of the means for preferably adjustable/controllable dosing of the at least one additional fluid in partial fluid streams into the at least one fibrous stock suspension which is connected with the common supply channel preferably has a circular cross sectional surface with a diameter of 2 to 10 mm, preferably 4 to 6 mm. In addition, the common supply channel of the means for preferably adjustable/controllable dosing of the at least one additional fluid in partial fluid streams into the at least one fibrous stock suspension preferably has a circular cross sectional surface with a diameter of 6 to 20 mm, preferably 10 to 15 mm. This surface area continuously ensures the feasibility of sufficiently large volume flows for the purpose of producing a fibrous web having high quality properties. The respective cross sectional surface can progress—at least in areas—constant, conical or stepped and the respective depth of the supply channel depends substantially on the number of rows of flow channels in the turbulence generator.
[0021] In addition the dosing channels of the means for preferably adjustable/controllable dosing of the at least one additional fluid in partial fluid streams into the at least one fibrous stock suspension which are connected with the common supply channel and which discharge through dosing channel openings on both sides of the side area of the means for preferably adjustable/controllable dosing can be arranged alternating. The dosing channels of the means for preferably adjustable/controllable dosing of the at least one additional fluid discharging at different heights can also be arranged at equal distances from each other. These embodiments allow for the greatest possible flexibility during design and operation of the headbox and ensure continually optimum conditions for the production of a fibrous web having high quality properties.
[0022] In an additional preferred embodiment the number of dosing channels in the means for preferably adjustable/controllable dosing of the at least one additional fluid is equal to the number of rows of flow channels in the downstream turbulence generator. This row-related dosing essentially provides process technological advantages.
[0023] Also, the number of dosing channels of the entire means for preferably adjustable/controllable dosing for the at least one additional fluid can be equal to the number of flow channels in the turbulence generator located downstream. This “1:1” dosing essentially provides additional process technological advantages.
[0024] The means for preferably adjustable/controllable dosing of the at least two fluids further advantageously have a preferably uniform spacing in width direction of the headbox in the range of 10 to 100 mm, preferably of 25, 33, 50 or 66 mm. This helps to ensure a high quality dosing of the at least two fluids across the entire width of the headbox.
[0025] The respective means for preferably adjustable/controllable dosing of fluid in partial fluid streams into the at least one fibrous stock suspension preferably comprises a dosing sword as described and illustrated in the German patent application DE 10 2008 054 898.7 (Applicant File: HPA14265 DE and Applicant-Title:“MJ II-DoS-TE-Geometry”) with same German application date as the German patent application corresponding to the present application. The relating disclosure content of German patent application DE 10 2008 054 898.7 is herewith made subject matter of the current description.
[0026] In regard to a compact design of the headbox it is also advantageous if the means in the form preferably of a dosing sword for preferably adjustable/controllable dosing of the at least two fluids in partial fluid streams into the at least one fibrous stock suspension has a length in the range of 60 to 350 mm, preferably 100 to 250 mm, and a height in the range of 50 to 300 mm, preferably 75 to 250 mm.
[0027] The fluid consists preferably of water, especially clarified water or white water, or of a fibrous stock suspension whose concentration is different than the average concentration of the at least one fibrous stock suspension in the headbox. These types of fluids have already proven themselves well in similar applications.
[0028] And the at least one additional fluid includes preferably at least one retention agent, especially high molecular compounds like polyamines, polyamidoamines, polyacrylamides, polyethylenimines, cationic starch or guarderviates, or a dewatering accelerator, especially polyamines or polyethylenimines.
[0029] The at least one additional fluid can however also include a chemical of a different kind, especially clarified water or white water, a filler, fines or other additive which can be used to produce fibrous webs.
[0030] The inventive headbox is extremely well suited for utilization in a machine for the production of a fibrous web, especially a paper or cardboard web. The fibrous web produced in the machine with at least one inventive headbox possesses outstanding properties throughout, since among other advantages, control of its fiber orientation cross profile as well as its base weight cross profile is possible.
[0031] The inventive headbox can of course also be in the embodiment of a multi-layer headbox. In this case all layers of the multi-layer headbox can be supplied by one and the same means for preferably adjustable/controllable dosing of at least one additional fluid in partial fluid streams into the at least one fibrous stock suspension.
BRIEF DESCRIPTION OF THE DRAWINGS
[0032] The above-mentioned and other features and advantages of this invention, and the manner of attaining them, will become more apparent and the invention will be better understood by reference to the following description of embodiments of the invention taken in conjunction with the accompanying drawings, wherein:
[0033] FIG. 1 is a vertical and schematic longitudinal sectional view of a headbox for a machine to produce a fibrous web from at least one fibrous stock suspension in accordance with the current state of the art;
[0034] FIG. 2 is a vertical and schematic longitudinal sectional view of a first inventive design form of a headbox for a machine to produce a fibrous web from at least one fibrous stock suspension;
[0035] FIG. 3 is a vertical and schematic longitudinal sectional view of a second inventive design form of a headbox for a machine to produce a fibrous web from at least one fibrous stock suspension;
[0036] FIGS. 4A to 4D are four schematic cross sectional views of a means for preferably adjustable/controllable dosing of two fluids in partial fluid streams;
[0037] FIGS. 5A to 5D are four additional schematic cross sectional views of a means for preferably adjustable/controllable dosing of two fluids in partial fluid streams; and
[0038] FIG. 6 is a schematic side view of the means for preferable adjustable/controllable dosing of two fluids of the headbox for a machine to produce a fibrous web from at least one fibrous stock suspension, illustrated in FIG. 2 .
[0039] Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrate embodiments of the invention, and such exemplifications are not to be construed as limiting the scope of the invention in any manner.
DETAILED DESCRIPTION OF THE INVENTION
[0040] FIG. 1 is a vertical and schematic longitudinal view of an exemplary design form of a headbox 1 , known from the current state of the art, for a machine to produce a fibrous web 3 from a fibrous stock suspension 2 . Illustrated headbox 1 may of course also be designed as a multi-layer headbox which utilizes at least two different fibrous stock suspensions to produce fibrous web 3 . Fibrous web 3 can in particular, be a paper, cardboard or tissue web.
[0041] Headbox 1 comprises one feed device 4 in the embodiment of an illustrated cross distribution pipe 5 or a circular distributor having a plurality of tubes and which is not illustrated, supplying the one fibrous stock suspension 2 (arrow).
[0042] Perforated distribution pipe plate 6 which is equipped with a plurality of channels 7 which are arranged in rows Z and columns S is located downstream adjacent to feed device 4 .
[0043] Again located adjacent downstream from perforated distribution pipe plate 6 is an intermediate channel 8 , extending across width B (arrow) of headbox 1 and which is equipped with several means 9 for preferably adjustable/controllable dosing of a fluid 10 in partial fluid streams 10 .T (arrows) into fibrous stock suspension 2 , the means being spaced apart from each other in width direction of headbox 1 . The individual means 9 for the preferably adjustable/controllable dosing respectively comprises several dosing channels 11 having a respective dosing channel opening 11 . 1 , discharging at different heights and being connected to a common supply channel 12 .
[0044] A turbulence generator 13 having a plurality of flow channels 14 arranged in rows Z and column S is located downstream from intermediate channel 8 . During operation of headbox 1 the fibrous stock suspension 2 is divided into partial fibrous streams in turbulence generator 13 and, after emerging from the turbulence generator is brought together again in a machine-wide chamber 15 in the embodiment of a headbox nozzle 16 comprising a nozzle gap 17 in order to enable formation of a machine-wide fibrous web 3 . As already known, flow channels 14 are in the embodiment of preferably thin-walled turbulence pipes and/or turbulence pipe inserts with at least partially constant, at least partially divergent, at least partially convergent and/or discontinuous cross sectional surfaces. A separating element which is well known to the expert and which is not explicitly illustrated, especially a lamella, may also be provided in headbox nozzle 16 . If a multitude of separating elements, especially lamellas are provided in headbox nozzle 16 , they can have different lengths and possibly also different properties, such as surface profiles, etc.
[0045] On its outlet side headbox nozzle 16 may be equipped with an aperture 18 , at least on one side, which is indicated by broken lines.
[0046] FIG. 2 shows a vertical and schematic longitudinal sectional view of a first inventive design form of a headbox 1 for a machine to produce a fibrous web from at least one fibrous suspension 2 . The basic construction of this headbox 1 is substantially consistent with the basic construction of headbox 1 schematically depicted in FIG. 1 . We therefore refer to the description provided for that drawing.
[0047] Feed device 4 is again followed by an adjacently located downstream perforated distribution pipe plate 4 which comprises a plurality of channels 7 arranged in rows Z and columns S.
[0048] Again located adjacent downstream from perforated distribution pipe plate 6 is an intermediate channel 8 , extending across width B (arrow) of headbox land which is equipped with several means 9 for preferably adjustable/controllable dosing of a fluid 10 (arrow) in partial fluid streams 10 .T (arrows) into fibrous stock suspension 2 (arrow), the means being spaced apart from each other in width direction of headbox 1 . The individual means 9 for the preferably adjustable/controllable dosing respectively comprises several dosing channels 11 having a respective dosing channel opening 11 . 1 , discharging at different heights and being connected to a common supply channel 12 .
[0049] A turbulence generator 13 having a plurality of flow channels 14 arranged in rows Z and column S is located downstream from intermediate channel 8 . As already known, flow channels 14 are in the embodiment of preferably thin-walled turbulence pipes and/or turbulence pipe inserts with at least partially constant, at least partially divergent, at least partially convergent and/or discontinuous cross sectional surfaces.
[0050] In a further development of the headbox 1 illustrated in FIG. 1 , the means 9 for preferably adjustable/controllable dosing of fluid 10 in partial fluid streams 10 .T (arrows) into fibrous stock suspension 2 of headbox 1 illustrated in FIG. 2 , is also designed for preferably adjustable/controllable dosing of one additional fluid 19 in partial fluid streams 19 .T (arrows) into fibrous stock suspension 2 . Herein the individual means 9 additionally comprises a plurality of dosing channels 20 for additional fluid 19 , each having a respective dosing channel opening 20 . 1 , discharging at different heights and being connected to a common supply channel 21 .
[0051] The dosing of additional fluid 19 into the one fibrous stock suspension 2 which is to be provided with a fluid 10 can be adjusted/controlled, at least in areas, in a manner obvious to the expert—in width direction B (arrow) of the headbox, in other words in “Y” direction and/or in height direction of the headbox, in other words in “Z” direction.
[0052] Dosing channels 11 of means 9 for preferably adjustable/controllable dosing of fluid 10 in partial fluid streams 10 .T (arrows) into fibrous stock suspension 2 which are connected with common supply channel 12 discharge through dosing channel openings 11 . 1 in downstream area 22 of means 9 for preferably adjustable/controllable dosing. In contrast, dosing channels 20 of means 9 for preferably adjustable/controllable dosing of additional fluid 19 in partial fluid streams 19 .T (arrows) into fibrous stock suspension 2 which are connected with common supply channel 21 discharge through dosing channel openings 20 . 1 on both sides of the side area 23 of means 9 for preferably adjustable/controllable dosing.
[0053] Furthermore, dosing channels 11 , 20 of means 9 for preferably adjustable/controllable dosing of fluid 10 and additional fluid 19 which discharge at different heights are arranged at equal distances A. Dosing channel openings 11 . 1 , 20 . 1 of dosing channels 11 , 20 can again be aligned toward each other, as shown in FIG. 2 .
[0054] FIG. 3 shows a vertical and schematic longitudinal sectional view of a second inventive design form of a headbox 1 for a machine to produce a fibrous web from at least one fibrous suspension 2 . The basic construction of this headbox 1 is substantially consistent with the basic construction of headbox 1 schematically depicted in FIG. 2 . We therefore refer to the description provided for that drawing.
[0055] In a further development of headbox 1 illustrated in FIG. 2 , the means 9 for preferably adjustable/controllable dosing of fluid 10 in partial fluid streams 10 .T (arrows) into fibrous stock suspension 2 of headbox 1 illustrated in FIG. 3 is also designed for preferably adjustable/controllable dosing of two additional fluids 19 , 24 in partial fluid streams 19 .T, 24 .T (arrows) into fibrous stock suspension 2 . Herein the individual means 9 respectively comprises a plurality of dosing channels 25 for additional fluid 24 , each having a respective dosing channel opening 25 . 1 , discharging at different heights and being connected to a common supply channel 26 .
[0056] Dosing of the two additional fluids 19 , 24 into the one fibrous stock suspension 2 which is to be provided with a fluid 10 can be adjusted/controlled, at least in areas, in a manner obvious to the expert—in width direction B (arrow) of headbox 1 , in other words in “Y” direction and/or in height direction of the headbox, in other words in “Z” direction.
[0057] Dosing channels 25 of means 9 for preferably adjustable/controllable dosing of the third fluid 24 in partial fluid streams 24 .T (arrows) into fibrous stock suspension 2 which are connected with common supply channel 26 discharge again through dosing channel openings 25 . 1 on both sides of side area 23 of means 9 for preferably adjustable/controllable dosing, upstream from dosing channel openings 20 . 1 of dosing channels 20 for the additional fluid 19 . Dosing channels 11 of means 9 for preferably adjustable/controllable dosing of fluid 10 in partial fluid streams 10 .T (arrows) into fibrous stock suspension 2 which are connected with common supply channel 12 discharge through dosing channel openings 11 . 1 in downstream area 22 of means 9 for preferably adjustable/controllable dosing. Dosing channels 11 , 20 of means 9 for preferably adjustable/controllable dosing of fluid 10 and the two additional fluids 19 , 24 which discharge at different heights are arranged at equal distances A. Dosing channel openings 11 . 1 , 20 . 1 , 25 . 1 of dosing channels 11 , 20 , 25 can again be aligned toward each other, as shown in FIG. 3 .
[0058] FIGS. 4A through 4D illustrate four schematic cross sectional views of a means 9 for preferably adjustable/controllable dosing of two fluids 10 , 19 in partial fluid streams 10 .T. 19 .T (arrows).
[0059] Dosing channels 11 of all means 9 for preferably adjustable/controllable dosing of fluid 10 in partial fluid streams 10 .T (arrows) into fibrous stock suspension 2 which are connected with common supply channel 12 discharge through dosing channel openings 11 . 1 in downstream area 22 of means 9 for preferably adjustable/controllable dosing.
[0060] In FIGS. 4B , 4 C and 4 D dosing channel openings 20 . 1 of dosing channels 20 of the three means 9 for preferably adjustable/controllable dosing of the additional fluid 19 in partial fluid streams 19 .T (arrows) into fibrous stock suspension 2 discharge respectively on both sides of side area 23 of respective means 9 for preferably adjustable/controllable dosing. In the design example in FIG. 4B dosing channels 20 discharge at an angle α of 90° relative to the flow direction R (arrow) of fibrous stock suspension 2 , in the example in FIG. 4C at an angle α of 45° relative flow direction R (arrow) of fibrous suspension 2 and in the example in FIG. 4D at an angle α of 135° relative to flow direction R (arrow) of fibrous stock suspension 2 .
[0061] Solely in the example in FIG. 4A dosing channel openings 20 . 1 of dosing channels 20 of means 9 for preferably adjustable/controllable dosing of the additional fluid 19 in partial fluid streams 19 .T (arrows) into fibrous stock suspension 2 discharge in one-sided side area 23 of medium 9 for preferably adjustable/controllable dosing at an angle α of 90° relative to flow direction R (arrow) of fibrous stock suspension 2 .
[0062] Dosing channels 20 which are connected with common supply channel 21 of the respective means 9 for preferably adjustable/controllable dosing of the additional fluid 19 in partial fluid streams 19 .T (arrow) into fibrous stock suspension 2 have a circular cross sectional surface 20 .A with a diameter 20 .D of 2 to 10 mm, preferably 4 to 6 mm. In addition, the common supply channel 21 of the individual means 9 for preferably adjustable/controllable dosing of the additional fluid 19 in partial fluid streams 19 .T (arrows) into fibrous stock suspension 2 has a circular cross sectional surface 21 .A with a diameter 21 .D of 6 to 20 mm, preferably 10 to 15 mm. The individual cross sectional surface 20 .A, 21 .A can progress—at least in areas—constant, conical or stepped.
[0063] In addition dosing channels 20 of means 9 for preferably adjustable/controllable dosing of fluid 19 in partial fluid streams 19 .T (arrows) into fibrous stock suspension 2 which are connected with the common supply channel 21 and which discharge through dosing channel openings 20 . 1 on both sides of the side area 23 of means 9 for preferably adjustable/controllable dosing can be arranged alternating.
[0064] For reasons of clarity only FIG. 4A shows all mentioned reference identifications.
[0065] FIGS. 5A through 5D show four additional cross sectional views of means 9 for preferably adjustable/controllable dosing of two fluids 10 , 19 in partial fluid streams 10 .T, 19 .T (arrows).
[0066] Dosing channels 11 of means 9 for preferably adjustable/controllable dosing of fluid 10 in partial fluid streams 10 .T (arrows) into fibrous stock suspension 2 which are connected with common supply channel 12 discharge through dosing channel openings 11 . 1 in downstream area 22 of means 9 for preferably adjustable/controllable dosing. Dosing channel openings 20 . 1 of dosing channels 20 of means 9 for preferably adjustable/controllable dosing of additional fluid 19 in partial fluid streams 19 .T (arrows) into fibrous stock suspension 2 respectively discharge at an angle α of 90° relative to the flow direction R (arrow) of fibrous stock suspension 2 on both sides of side area 23 of respective means 9 for preferably adjustable/controllable dosing.
[0067] The number of dosing channels 20 of means 9 for preferably adjustable/controllable dosing of additional fluid 19 is the same as the number of rows Z of flow channels 14 of downstream turbulence generator 13 . In addition, the number of dosing channels 20 of all means 9 for preferably adjustable/controllable dosing for additional fluid 19 is the same as the number of flow channels 14 of downstream turbulence generator 13 .
[0068] For reasons of clarity only FIG. 5A shows all mentioned reference identifications.
[0069] FIG. 6 shows a schematic side view of means 9 for preferably adjustable/controllable dosing of two fluids 10 , 19 (arrows) in partial fluid streams 10 .T, 19 .T (arrows) of headbox 1 for a machine to produce a fibrous web from at least one fibrous stock suspension.
[0070] Means 9 for preferably adjustable/controllable dosing of at least two fluids 10 , 19 (arrows) in partial fluid streams 10 .T, 19 .T (arrows) into the at least one fibrous stock suspension 2 comprises a dosing sword 9 . 1 .
[0071] Means 9 in the form of dosing sword 9 . 1 for preferably adjustable/controllable dosing has a length 9 .L in the range of 60 to 350 mm, preferably 100 to 250 mm and, depending upon the height of the intermediate chamber of headbox 1 has a height 9 .H in the range of 50 to 300 mm, preferably 75 to 250 mm. Means 9 , 9 . 1 for preferably adjustable/controllable dosing have preferably uniform spacing T in width direction of headbox 1 in the range of 10 to 100 mm, preferably 25, 33, 50 or 66 mm (also compare FIGS. 2 and 3 ).
[0072] Dosing sword 9 . 1 is described and illustrated in the German patent application DE 10 2008 054 898.7 (Applicant File: HPA14265 DE and Applicant-Title: “MJ II-DoS-TE-Geometry”) with same German application date as the German patent application corresponding to the present application. The relating disclosure content of German Patent application DE 10 2008 054 898.7 is herewith made to the subject matter of the current description.
[0073] The properties of the design forms of respective inventive headbox 1 , described in FIGS. 2 through 6 may be combined, at least partially, in ways obvious to the expert.
[0074] Fluid 10 flowing through the respective inventive headbox 1 in FIGS. 2 through 6 consists at least of water, especially clarified water, especially clarified water or white water or of at least one fibrous stock suspension whose concentration is different than the average concentration of the at least one fibrous stock suspension 2 flowing in headbox 1 . In contrast, the at least one additional fluid 19 , 24 flowing through inventive headbox 1 includes at least one retention agent, especially high molecular compounds like polyamines, polyamidoamines, polyacrylamides, polyethylenimines, cationic starch or guarderviates or a dewatering accelerator, especially polyamines or polyethylenimines.
[0075] Headbox 1 , respectively illustrated and described in the drawings is especially suited for utilization in a machine to produce a fibrous web 3 , in particular a paper or cardboard web from at least one fibrous stock suspension 2 .
[0076] In summary it must be stated that a headbox of the type described at the beginning is improved by the invention in that the aforementioned disadvantages of the current state of the art are eliminated to the greatest possible extent, preferably completely. The headbox hereby enables in particular an efficient and cost effective addition of the at least additional fluid into the at least one fibrous suspension to which a fluid is added.
[0077] While this invention has been described with respect to at least one embodiment, the present invention can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.
COMPONENT IDENTIFICATION
[0000]
1 Headbox
2 Fibrous stock suspension (arrow)
3 Web
4 Feed device
5 Cross distributor pipe
6 Perforated distributor pipe plate
7 Channel
8 Intermediate channel
9 Means for preferable adjustable/controllable dosing of a fluid
9 . 1 Dosing sword
9 .H Height
9 .L Length
10 Fluid (arrow)
10 .T Partial fluid stream (arrow)
11 Dosing channel
11 . 1 Dosing channel opening
12 Supply channel
13 Turbulence generator
14 Flow channel
15 Machine-wide chamber
16 Headbox nozzle
17 Nozzle gap
18 Aperture
19 Fluid
19 .T Partial fluid stream (arrow)
20 Dosing channel
20 . 1 Dosing channel opening
20 .A Cross sectional surface
20 .D Diameter
21 Supply channel
21 .A Cross sectional surface
21 .D Diameter
22 Downstream area
23 Side area
24 Fluid
24 .T Partial fluid stream (arrow)
25 Dosing channel
25 . 1 Dosing channel opening
26 Supply channel
A Distance
B Width; width direction (arrow)
R Flow direction (arrow)
S Column
T Spacing (arrow)
Z Row
α Angle
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The invention relates to a headbox for a machine for producing a fibrous web, in particular a paper or cardboard web, from at least one fibrous stock suspension, having a feed apparatus which feeds the at least one fibrous stock suspension, having a distributor-pipe perforated plate which is adjacent downstream and has a multiplicity of channels which are arranged in rows and in columns, having an intermediate channel which lies downstream of the latter, extends over the width of the headbox and has a plurality of means which are spaced apart from one another in the width direction of the headbox for the preferably regulatable/controllable metering of a fluid in fluid part streams into the at least one fibrous stock suspension. The headbox according to the invention is characterized in that the means for the preferably regulatable/controllable metering of the fluid in fluid part streams into the at least one fibrous stock suspension is also configured for the preferably regulatable/controllable metering of at least one further fluid in fluid part streams into the at least one fibrous stock suspension, wherein the individual means comprises in each case a plurality of metering channels for the at least one further fluid, which metering channels have a respective metering-channel opening, open at different heights and are connected to a common supply channel.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] None.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not Applicable.
BACKGROUND OF THE INVENTION
[0003] This invention relates to compositions of matter and methods of using them to improve the physical properties of manufactured paper, in particular making soft tissue paper. Typically, tissue paper obtains its characteristic properties of softness, bulk, absorbency, and ability to stretch, by a process involving a Yankee Dryer apparatus. In conventional tissuemaking the tissue is fed to the Yankee Dryer apparatus as a wet fiber web. The wet fiber web is significantly dewatered at a pressure roll nip where the sheet is transferred to the surface of a Yankee Dryer cylinder. At this point, the paper web typically has 35-40% consistency (it is 65-60% water). The sheet is further dried by the steam-heated Yankee Dryer cylinder and hot air impingement hoods to 90-98% consistency and removed with a doctor blade. The mechanical action of the blade results in a disruption of the fiber-fiber bonds, which forms a microfold structure that gives the tissue paper its characteristic properties. This process is referred to as creping.
[0004] In order to properly crepe a paper web to make soft tissue paper, the paper web has to adhere to the surface of the Yankee dryer cylinder. When the paper web then collides with the doctor blade, microfolds are formed in the machine direction by the compressing, or shortening action, while at the same time the web is separated from the drying cylinder. This adhesion is facilitated by the application of an adhesive to the surface of the dryer cylinder. In addition, wet-end furnish components can also contribute to the adhesion that occurs. Commonly used Yankee adhesives are synthetic polymers such as polyaminoamide-epichlorohydrin (PAE) resins, polyamine-epichlorohydrin resins, polyvinyl alcohols, polyvinyl acetates, polyacrylamides, polyamines, polyvinylamines, polyamides, polyvinylpyrrolidones, polyethers, polyethyleneimines, crosslinked vinyl alcohol copolymers, and others described in U.S. Pat. No. 5,374,334. Other natural and derivitized natural polymers may also be employed including starch, guar gum, carboxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose and the like. Various lower molecular weight compounds, release agents, oils and surfactants, are used to modify the properties of these adhesives.
[0005] The tissue industry has a continuing interest in manufacturing premium grade tissues, which are tissues with high levels of softness and bulk. Improvements in softness can be obtained by modifying the fiber source, implementing particular forming and drying strategies, creping the fiber sheets, and by using wet-end or topical application of softening agents. Creping the paper sheet when it has a very low sheet moisture level (<3%) is a very effective way of achieving desired levels of high softness and bulk. At low moisture levels, the sheet and the coating tend to adhere to each other more strongly which causes the sheet to debond in the Z-direction more efficiently thereby generating greater bulk and softness. Low moisture levels can be achieved by increasing the temperature of the Yankee dryer and hoods.
[0006] Despite the benefits for tissue softness, low moisture creping is not being widely practiced due in part to coating runnability issues. Conventional creping adhesives typically develop a hard coating which is less rewettable after undergoing the high temperatures and extensive drying that is required for low moisture creping. This hard and brittle coating results in a loss of adhesion and also results in blade vibration (chatter), which can cause non-uniform creping, blade wear, and, in extreme cases, damage to the Yankee dryer cylinder surface.
[0007] One attempted method of addressing these problems is by using humectants to plasticize the adhesive and thereby counteract many of the consequences of high Yankee Dryer temperatures. One such humectant is glycerol (see for example U.S. Pat. Nos. 5,187,219 and 5,660,687). Glycerol has been shown to alter the viscoelastic properties of a coating film. In addition, it decreases the glass transition temperature and shear modulus of the film, making it softer and more rewettable in both high and low temperature conditions. Unfortunately when in dilute aqueous form, as is the case when applied to Yankee dryers, the volatility of glycerol/water mixtures limits glycerol's effectiveness as a plasticizer. Because water is also common in Yankee Dryer environments there is a great demand for a modifying agent that placticizes the film but is not as volatile as glycerol.
BRIEF SUMMARY OF THE INVENTION
[0008] At least one embodiment of the invention is directed towards a method of creping a paper web comprising the steps of:
[0000] a) applying to a rotating creping cylinder a coating composition, the coating composition comprising at least one adhesive agent, at least one release agent, and at least one polyglycerol;
b) pressing the paper web against the creping cylinder to effect adhesion of the paper web to the creping cylinder; and
c) dislodging the paper web from the creping cylinder with a doctor blade.
[0009] The coating composition can remain plasticized at a temperature beyond the volatility limit of glycerol. The polyglycerol can be between 1 and 70% of the coating composition. The coating composition can have a glass transition temperature of less than 100° C. The coating composition can be readily rewettable after the paper has been dislodged from the creping cylinder.
[0010] The polyglycerols can be selected from the group consisting of polyglycerol according to the formula:
[0000]
[0000] wherein m, n, o, p, q, and r are equal to an integer from 0 to 25 polyglycerol formed by crosslinking glycerol with epichlorohydrin, base condensation polyglycerols, polymerization of glycidol-based monomers, and any combination thereof.
[0011] The polyglycerol structure can be selected from the group consisting of linear, branched, hyperbranched, dendritic, cyclic and any combination thereof. The polyglycerol can have a molecular weight greater than 100 g/mole. The coating can further comprise polyaminoamide-epichlorohydrin (PAE) resins, polyamine-epichlorohydrin resins, polyacrylamides, polyvinylamines, polyvinylpyrrolidones, natural polymers, derivitized natural polymers, starch, guar gum, carboxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, functional additives, organic quaternary salts having fatty chains of about 12 to about 22 carbon atoms, dialkyl imidazolinium quaternary salts, dialkyl diamidoamine quaternary salts, monoalkyl trimethylammonium quaternary salts, dialkyl dimethylammonium quaternary salts, trialkyl monomethylammonium quaternary salts, ethoxylated quaternary salts, dialkyl and trialkyl ester quaternary salts, polysiloxanes, quaternary silicones, organoreactive polysiloxanes, amino-functional polydimethylsiloxanes, polyamines, polyamides, polyamidoamines, amidoamine-epichlorohydrin polymers, polyethyleneimines, polyvinyl alcohol, vinyl alcohol copolymers, polyvinyl acetate, vinyl acetate copolymers, polyethers, polyacrylic acid, acrylic acid copolymers, cellulose derivatives, starches, starch derivatives, animal glue, crosslinked vinylamine/vinylalcohol polymers, glyoxalated acrylamide/diallyldimethyl acrylamide copolymers, halogen-free creping cylinder adhesives based on cross-linked cationic polyaminoamide polymers, and any combination thereof. The coating composition can further comprise lactic acid or lactate, can further comprise release agents, other modifiers (including phosphates), and functional additives, polyglycerols, polyglycerol derivatives, any other glycerol-based polyols, and any combination thereof.
[0012] The release aid can comprise one item selected from the group consisting of: release oils composed of naphthenic, paraffinic, vegetable, mineral or synthetic oil and emulsifying surfactants, release aids formulated with one or more surfactants such as fatty acids, alkoxylated alcohols, alkoxylated fatty acids, and any combination thereof. The coating composition can be applied as an aqueous solution, an emulsion, or a dispersion. Creped paper can be prepared according to the inventive method.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] A detailed description of the invention is hereafter described with specific reference being made to the drawings in which:
[0014] FIG. 1 is an illustration of the structure of suitable polyglycerols for use in the inventive film.
[0015] FIG. 2 is an illustration of the structures of suitable repeating units, which may be used in the polyglycerols used in the inventive film.
[0016] FIG. 3 is a graph showing the improved volatility properties of the inventive modifiers.
[0017] FIG. 4 is a graph showing the improved resistance to weight loss of the diluted modifiers.
[0018] FIG. 5 is a graph showing the improved dry tack strength of the inventive film.
DETAILED DESCRIPTION OF THE INVENTION
Definitions
[0019] For purposes of this application the definition of these terms is as follows:
[0020] “Dispersion” means a thermodynamically unstable mixture of extremely fine solid particles, typically of colloidal size, which are highly dispersed throughout a continuous phase liquid that it is otherwise immiscible with. Dispersions can be at least temporarily stabilized by dispersing agents.
[0021] “Emulsion” means a thermodynamically unstable mixture of a dispersed phase liquid, which is highly dispersed as small globules throughout a continuous phase liquid that it is otherwise immiscible with. Emulsions can be at least temporarily stabilized by surfactants and emulsifiers.
[0022] “Polymeric Polyol” means a polymer in which the monomer repeating units comprising the polymer are at least in part polyols and includes but is not limited to polyglycerols, polyglycerols derivatives, and a polymer consisting of at least one glycerol monomer unit and at least another monomer unit to other multiple monomers units regardless of the sequence of monomers unit arrangements and any combination thereof.
[0023] “Polyol” means a compound or polymer containing at least two hydroxyl groups in which each of these at least two hydroxyl groups are attached to separate carbon atoms of an aliphatic skeleton, including but not limited to glycols, glycerol, pentaerythritol, trimethylolethane, trimethylolpropane, 1,2,6-hexanetriol, sorbitol, inositol, poly(vinyl alcohol) and glycerol-based polyols.
[0024] “Placticizer” means a substance which when added to a material causes an increase in the flexibility and workability of that material, often as a result of lowering the glass transition temperature of that material.
[0025] In the event that the above definitions or a definition stated elsewhere in this application is inconsistent with a meaning (explicit or implicit) which is commonly used, in a dictionary, or stated in a source incorporated by reference into this application, the application and the claim terms in particular are understood to be construed according to the definition in this application, and not according to the common definition, dictionary definition, or the definition that was incorporated by reference.
[0026] At least one embodiment of the invention is directed towards a Yankee Dryer coating composition comprising an adhesive, a release agent, and a modifying agent. The adhesive binds a paper mat to the drum surface of the Yankee Dryer. The invention encompasses applications to paper mats comprising cellulosic fibers, synthetics fibers, and any combination thereof. The release agent reduces the strength of the adhesive to allow a doctor blade to remove the dried paper mat from the drum. The modifying agent plasticizes the coating composition, keeping it soft, and allowing it to become rewetted and to maintain the adhesion while in the presence of high temperature. A description of Yankee Dryer coating compositions is given in U.S. patent application Ser. No. 12/273,217.
[0027] In at least one embodiment the modifying agent is a composition that comprises glycerol-based polymeric polyol, including polyglycerols, polyglycerol derivatives, and a polymer consisting of at least one glycerol monomer unit and at least another monomer unit to other multiple monomers units regardless of the sequence of monomers unit arrangements. Suitable glycerol-based polymeric polyol include but are not limited to those described in U.S. patent application Ser. No. 12/582,827 and US Published Patent Application 2009/0130006. In at least one embodiment the polymeric polyol has a molecular weight of more than 100.
[0028] In at least one embodiment the modifying agent is a composition that comprises polyglycerols. Suitable polyglycerols include but are not limited to those described in U.S. patent application Ser. No. 12/582,827 and US Published Patent Application 2009/0130006. In at least one embodiment the polyglycerol has a molecular weight of more than 100. Although it is known that glycerol does have some use as a plasticizer in other materials, for example as described in U.S. Pat. No. 5,187,219, it has not been previously attempted to use polyglercerol in Yankee dryer coatings.
[0029] In at least one embodiment, the polyglycerol is one selected from the list consisting of diglycerol, triglycerol, and higher analogs, as specified by the structure illustrated in FIG. 1 . The polyglycerols may be prepared by crosslinking with epichlorohydrin, through the condensation of glycerol, by polymerization of glycidol-based monomers, or any combination thereof.
[0030] In at least one embodiment, the polyglycerol may have a structure as illustrated in FIG. 1 . The polyglycerol comprises a structure including at least two repeating units selecting from at least one of the structures listed in FIG. 2 including but not limited to linear structures I and II, branched, hyperbranched or dendritic structures III, IV, and VIII, cyclic structures V, VI and VII and any combination thereof. Any structure in FIG. 2 can be combined with any structure or structures including itself through any free hydroxyl group functionality in the structure. The cyclic linkages of any basic cyclic structures in FIG. 2 may contain any structure or structures as a part or parts of linkages. In FIG. 1 and FIG. 2 the numbers m, n, n′, o, p, q and r in each structure can independently be any numeric number 0, 1, 2, . . . 25. In FIG. 1 R and R′ are (CH 2 ) n and n can independently be 1 or 0.
[0031] In at least one embodiment the modifying agent for Yankee coatings comprises polyglycerol derivatives. The derivatives can be obtained by derivatization of polyglycerols with 1 to 22 carbon atoms. The modification includes but not is limited to alkylation, alkoxylation, esterification and the like.
[0032] In at least one embodiment the adhesive compositions of the present invention are applied to the surface of a creping cylinder as a dilute aqueous solution. In an embodiment, the aqueous solution includes from about 0.01 to about 10.0 weight percent of the polymers of the invention. In another embodiment, the polymers of the invention are included in the aqueous solution in a concentration of from about 0.05 to about 5.0 weight percent. In another embodiment, the polymers of the invention are included in the aqueous solution in a concentration of from about 0.1 to about 1.0 weight percent. Those skilled in the art of creping adhesives will appreciate that the reason for such a larger percentage of water in the admixture is in part based on the need to only deposit a very thin layer of adhesive on the creping cylinder, which, in one embodiment, is most easily accomplished with a spray boom.
[0033] In at least one embodiment the spraying applications described above may be further improved by a variety of means, for example by using spraybooms designed for double or triple coverage, by oscillating the sprayboom and by recirculation of the diluted release aid composition from the outlet of the sprayboom to improve mixing and reduce the possibility of separation.
[0034] In at least one embodiment a release aid that is also in aqueous form is applied to the Yankee dryer along with the polymer adhesive. The release aid provides lubrication between the Yankee dryer surface and the doctor blade used to crepe the tissue paper from the Yankee dryer. The release aid also allows the tissue paper to release from the adhesive during the creping process. Representative release aids include release oils composed of naphthenic, paraffinic, vegetable, mineral or synthetic oil and emulsifying surfactants. In order to form stable aqueous dispersions the release aid is typically formulated with one or more surfactants such as fatty acids, alkoxylated alcohols, alkoxylated fatty acids, and the like. The release aid may be applied to the creping cylinder before or after the adhesive composition, or may be added together with the adhesive for application to the creping cylinder.
[0035] In at least one embodiment the adhesive compositions of this invention may also be used in combination with functional additives used in the art to improve the softness of the tissue or towel. Representative functional additives include organic quaternary salts having fatty chains of about 12 to about 22 carbon atoms including dialkyl imidazolinium quaternary salts, dialkyl diamidoamine quaternary salts, monoalkyl trimethylammonium quaternary salts, dialkyl dimethylammonium quaternary salts, trialkyl monomethylammonium quaternary salts, ethoxylated quaternary salts, dialkyl and trialkyl ester quaternary salts, and the like. Additional suitable functional additives include polysiloxanes, quaternary silicones, organoreactive polysiloxanes, amino-functional polydimethylsiloxanes, and the like.
[0036] In at least one embodiment the creping adhesives for preparing creped paper include, but are not limited to, the following: polyamines, polyamides, polyamidoamines, amidoamine-epichlorohydrin polymers, polyethyleneimines, polyvinyl alcohol, vinyl alcohol copolymers, polyvinyl acetate, vinyl acetate copolymers, polyethers, polyacrylic acid, acrylic acid copolymers, cellulose derivatives, starches, starch derivatives, animal glue, crosslinked vinylamine/vinylalcohol polymers as described in U.S. Pat. No. 5,374,334, glyoxalated acrylamide/diallyldimethyl acrylamide copolymers; the polymers described and claimed in U.S. Pat. No. 5,179,150; the polymers described and claimed in U.S. Pat. No. 5,187,219; an admixture of from about 0.1 to about 50 weight percent of a first polyamide-epihalohydrin resin and from about 99.9 to about 50 weight percent of a second polyamide-epihalohydrin resin, as described and claimed in U.S. Pat. No. 6,277,242 B1 and halogen-free creping cylinder adhesives based on cross-linked cationic polyaminoamide polymers as described and claimed in U.S. Pat. No. 5,382,323.
EXAMPLES
[0037] The foregoing may be better understood by reference to the following examples, which are presented for purposes of illustration and are not intended to limit the scope of the invention.
[0038] Various polyglycerol samples were characterized to determine their bulk viscosity and molecular weight including, commercially available Diglycerol and Polyglycerol-3 from Solvay Chemical International (Belgium) and synthesized materials PG-1, and PG-2 available from Nalco Company (Naperville, Ill.). A description of these samples is provided in Table 1 and shows all of the samples had a higher viscosity and molecular weight than glycerol (MW=92 g/mole). The bulk viscosity of samples was measured by a Rheometer AR2000 (TA Instruments, New Castle, Del.). The measurements were performed in a rotational mode at a shear rate of 5 s −1 and 40° C. A 60 mm parallel plate was used with a gap of 2000 μm. For molecular weight measurements, all samples were analyzed with a SEC method (size exclusion chromatography) and the reported molecular weights (MW) were weight average molecular weights based on calibration of PEG/PEO standards. Base condensation prepared polyglycerols can contain lactic acid or lactate.
[0000]
TABLE 1
Descriptions and molecular weight characterizations
of polyglycerol samples
Type of
Viscosity
Sample
Polyglycerol
(Pa · s)
Mw*
Glycerol
—
0.26
92
Diglycerol
Epi-erosslinked
2.3
140
Polyglycerol-3
Epi-crosslinked
6.6
200
PG-1
Base Condensation
35
320
PG-2
Base Condensation
130
540
*Excludes glycerol monomer
Example 1
[0039] General procedure for the production of polyglycerols: A reaction mixture of glycerol (500.0 parts) and NaOH or KOH solution (3 to 10% by weight of active relative to the total weight of reaction solids) was stirred and gradually heated up to 230 to 260 degrees Celsius under particular inert gas flow rates. The reaction mixture was stirred at this temperature for a desired reaction time (in hours), and in-process samples were drawn after two hours and every one or two hours thereafter for product characterizations. Nitrogen flow rates at 0.2 to 8 mol of nitrogen per hour for each mol of glycerol or vacuum pressures less than 760 mm Hg were applied starting from reaction time between 0 to 4 hours to the end of the reaction. The polyglycerol products were used for the application directly or after dilution with water, with or without pH adjustment.
Example 2
[0040] The volatility of polyglycerol samples was determined by thermogravimetry (TGA). FIG. 3 is the overlay of TGA weight-loss curves for glycerol and various polyglycerol samples. Table 2 lists the temperature at which 5% weight-loss occurs in the samples. The 5% weight-loss of glycerol occurs at 162° C., whereas the 5% weight-loss of polyglycerol samples occurs at significantly higher temperatures. This indicates that all of the polyglycerol samples are less volatile than glycerol. About 20-40 mg of samples were analyzed by TGA (TA Instruments, New castle, DE) at a heating rate of 10° C./min in an air atmosphere (flow rate: 90 ml/min).
[0000]
TABLE 2
5% weight-loss temperature determined by TGA
Sample
Temperature (° C.)
Glycerol
162
Diglycerol
235
Polyglycerol-3
255
PG-1
192
PG-2
204
Example 3
[0041] The lower volatility of polyglycerol compared to glycerol in dilute aqueous solutions is illustrated in FIG. 4 . As the modifier concentration becomes more dilute, the advantage of polyglycerol over glycerol becomes more apparent. At 1% modifier concentration, practically 100% of the glycerol modifier is lost after drying at 105° C. for 16.5 hours. In contrast only 10% of the polyglycerol modifier is lost.
Example 4
[0042] The plasticizing properties of polyglycerol, when formulated as part of a Yankee dryer composition, was demonstrated from glass transition temperature (Tg) and shear storage modulus (G′) measurements. The polymer Tg was measured by Differential Scanning Calorimetry, and the G′ of the polymer film was measured by rheometer. Table 3 shows the effect of modifiers on the Tg and G′ of PAE-based film. The results demonstrate that polyglycerol is as an effective plasticizer as glycerol. Polyglycerol reduced the Tg in a similar fashion as glycerol, and the polyglycerol-modified PAE film is a softer film compared to the unmodified film. A TA Q200 Differential Scanning Calorimeter (TA Instruments, New Castle, Del.) was used for Tg measurement. Polymer samples were prepared by casting films in a polypropylene dish. The samples were dried at 105° C. in an oven overnight. About 10-15 mg of sample was sealed in a DSC pan with lid. The sample was heated at a rate of 10° C./min Tg was determined from the second scan using a half height method. The shear storage modulus G′ was measured by a rheometor AR2000 (TA Instruments, New Castle, Del.). Polymer films were prepared by casting from a 5% (w/w) solution. The film was dried in an oven at 95° C. overnight. The dry film was punched with a die (8 mm in diameter). The 8 mm disc was further dried in a vacuum oven at 110° C. for two hours. The shear storage modulus G′ was measured using 8 mm parallel plate at 110° C. and 1 Hz.
[0000]
TABLE 3
Effects of modifiers on the glass transition temperature
and shear storage modulus of PAE resin
Sampale
Tg (° C.)
G′ (kPa)
PAE
76
1500
PAE + Glycerol
55
510
PAE + PG-2
57
770
Example 5
[0043] In order to compare the effect of polyglycerols and glycerol on adhesion, a dry tack peel test was performed. This test measured the force required to peel a cotton strip adhered to a heated metal plate. First a PAE adhesive composition was applied to the metal plate by a #40 coating rod. The adhesive applied to the plate had no more than 15% solids. The plate was heated to 100° C. and a dry cotton strip was pressed against the plate by a 1.9 kg cylindrical roller. The metal plate was then heated to 105° C. and the strip was left to dry for 15 minutes. The metal plate was then clamped to a testing apparatus and the cloth was peeled off the plate at an angle of 180° at a constant speed. The results of the test shown in FIG. 5 demonstrate the effectiveness of the invention. The sample with no modifier showed no dry tack adhesion because as the PAE adhesive film dried out, the film became brittle and too hard for the cotton strip to adhere to. While the glycerol modifier can make the film softer which increased the dry tack adhesion, FIG. 5 makes clear that the polyglycerol containing films, had superior dry tack adhesion when compared to films containing glycerol as a modifier.
[0044] This data also makes clear that because polyglycerol functions as such an effective placticizer, even if in a rare circumstance, a residual amount of glycerol would be present in a sample of polyglycerol modified film, the residual glycerol would not function effectively as a plasticizer for the polyamidoamine/epihalohydrin since the greater abundance and effectiveness of the polyglycerol would overwhelm any effect from residual glycerol. Moreover FIG. 3 makes clear that because polyglycerols are less volatile under certain conditions of use, (for example 100 to 162 degree environments) in those conditions, glycerol is not an effective plasticizer for the polyamidoamine/epihalohydrin resin because it vaporizes away while the retained polyglycerols do function as placticizers.
[0045] While this invention may be embodied in many different forms, there are shown in the drawings and described in detail herein specific preferred embodiments of the invention. The present disclosure is an exemplification of the principles of the invention and is not intended to limit the invention to the particular embodiments illustrated. All patents, patent applications, scientific papers, and any other referenced materials mentioned herein are incorporated by reference in their entirety. Furthermore, the invention encompasses any possible combination of some or all of the various embodiments described herein and incorporated herein.
[0046] The above disclosure is intended to be illustrative and not exhaustive. This description will suggest many variations and alternatives to one of ordinary skill in this art. All these alternatives and variations are intended to be included within the scope of the claims where the term “comprising” means “including, but not limited to”. Those familiar with the art may recognize other equivalents to the specific embodiments described herein which equivalents are also intended to be encompassed by the claims.
[0047] All ranges and parameters disclosed herein are understood to encompass any and all subranges subsumed therein, and every number between the endpoints. For example, a stated range of “1 to 10” should be considered to include any and all subranges between (and inclusive of) the minimum value of 1 and the maximum value of 10; that is, all subranges beginning with a minimum value of 1 or more, (e.g. 1 to 6.1), end ending with a maximum value of 10 or less, (e.g. 2.3 to 9.4, 3 to 8, 4 to 7), and finally to each number 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10 contained within the range.
[0048] This completes the description of the preferred and alternate embodiments of the invention. Those skilled in the art may recognize other equivalents to the specific embodiment described herein which equivalents are intended to be encompassed by the claims attached hereto.
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The invention provides a composition of matter useful for producing very soft high grades of tissue paper. The composition of matter comprises an adhesive composition that includes a glycerol-based polyol. The glycerol-based polyol prevents the composition from becoming brittle and is non-volatile. This allows the composition to become rewetted after creping and allows for strong levels of adhesion even at high temperatures.
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This invention relates to the recovery of hydrocarbon fluids from subterranean formations. More particularly, the invention relates to a novel well treatment fluid, a process for its preparation, and to a method of treating or fracturing a subterranean formation using such fluid.
BACKGROUND OF THE INVENTION
In the process of recovering hydrocarbon values from subterranean formations, it is common practice to treat a hydrocarbon-bearing formation with a pressurized fluid to provide flow channels, i.e., to fracture the formation, or to use such fluids to control sand to facilitate flow of the hydrocarbons to the wellbore. Well treatment fluids, particularly those used in fracturing, typically comprise a water or oil based fluid incorporating a thickening agent, normally a polymeric material. The thickening agent helps to control leak-off of the fluid into the formation, and aids in the transfer of hydraulic fracturing pressure to the rock surfaces. Primarily, however, the thickening agent permits the suspension and transfer into the formation of proppant materials which remain in the fracture or sand when the hydraulic pressure is released, thereby holding the fracture open or stabilizing the sand.
Typical polymeric thickening agents for use in such fluids comprise galactomannan gums, such as guar and substituted guars such as hydroxypropyl guar and carboxymethylhydroxypropyl guar. Cellulosic polymers such as hydroxyethyl cellulose may be used, as well as synthetic polymers such as polyacrylamide. To increase the viscosity, and, therefore, the proppant carrying ability of the fracturing fluid, as well as increase its high temperature stability, crosslinking of the polymeric materials employed is also commonly practiced. Typical cross linking agents comprise soluble boron, zirconium, and titanium compounds.
By necessity, well treatment fluids are prepared on the surface, and then pumped through tubing in the wellbore to the hydrocarbon-bearing subterranean formation. While high viscosity, thickened fluid is highly desirable within the formation in order to transfer hydraulic pressure efficiently to the rock and to reduce fluid leak-off, large amounts of energy are required to pump such fluids through the tubing into the formation. To reduce the amount of energy required, various methods of delaying crosslinking have been developed. These techniques allow the pumping of a relatively less viscous fluid having relatively low friction pressures within the well tubing with crosslinking being effected near or in the formation so that the advantageous properties of thickened crosslinked fluid are available at the rock face.
One typical delayed crosslinking well treatment fluid system comprises borate crosslinked galactomannan gums such as guar or hydroxypropyl guar. The galactomannan polymers, which may be provided as a solid or as a suspension in a hydrocarbon, hydrate in neutral or acidic solution to form a gel. Under these conditions, i.e., pH of 7 or lower, no crosslinking of guar or hydroxypropyl guar will occur with borate ion. To effect borate crosslinking of guar and hydroxypropyl guar, the pH must be raised to at least 9.0. The requirement to raise the pH to this level has been exploited to delay the crosslinking of the galactomannan gums by borate ion.
The practice of delaying crosslinking of thickening agents in such fluids, however, presents its own set of difficulties. Thus, sophisticated techniques must be employed to adjust the pH of the fluid at the proper location, i.e., in or near the formation. U.S. Pat. No. 5,259,455, for example, describes the practice of controlled dissolution of MgO in a fracturing fluid to provide such pH adjustment. To be able to operate effectively where formation temperatures are above 200° F., the patent discloses additives to prevent the magnesium precipitation which would lower the pH of the system.
An alternative approach to downhole pH adjustment would be some reduction of the concentration of the thickening agent in the well treatment fluid, with crosslinking being accomplished or being only slightly delayed, the reduced loading thereby reducing the friction penalty. However, reduction of the thickening agent concentration (i.e., use of a lower concentration) in such fluids has not been practiced to any significant extent because of a long-established belief by those skilled in the art that minimum levels of loading of the thickening agents mentioned are required for effective or sufficient crosslinking. In the case of guar, for example, this concentration has been considered to be about 17 pounds of guar per one thousand gallons of aqueous fracturing fluid. This belief was based on studies of the radius of gyration of the guar molecule and the theory that if the radius of gyration of two molecules in solution do not overlap, the molecules cannot be crosslinked to produce the type of gel required for reliable fracturing operations. As a general proposition, most well treatment solutions employed in the field utilizing crosslinking of the thickening agent prior to the invention have utilized concentrations of the delayed crosslinking thickening agents that are well above the level mentioned, and, typically, 30 pounds per 1000 gallons of liquid or greater are used.
Accordingly, a need has existed for a well treatment fluid, especially a fracturing fluid, that exhibits relatively low friction loss in the well tubing, while avoiding the difficulties associated with raising the pH at the proper time or location, and further avoids those difficulties associated with insufficient crosslinking. Further, there has existed a need for an effective fluid having reduced concentrations of thickening agent or agents, thereby reducing the costs of such solutions and improving the conductivity of the formations. Finally, there has existed a need for a method of treating or fracturing a subterranean formation characterized by use of a low cost fracturing fluid that is not dependent on precision pH adjustment downhole. The invention addresses these needs.
SUMMARY OF THE INVENTION
Surprisingly, it has been found that the hydrated galactomannan gum component of a low or reduced concentration hydrated galactomannan gum containing fluid may be crosslinked by a suitable metal crosslinking agent if appropriate buffering of the fluid is provided. Moreover, it has been found that buffered, low concentration hydrated metal crosslinked galactomannan gum thickened fluids according to the invention are effective well treatment fluids that are easily transported down well with significant energy saving. Accordingly, in one embodiment, the invention relates to a novel well treatment fluid composition comprising an aqueous hydrated metal crosslinked galactomannan gum solution buffered to a pH of from about 9.0 to about 12, preferably from about 9.5 to about 11.75. More particularly, the invention relates to a well treatment fluid of the galactomannan gum type which is buffered by the addition of or which contains a selected buffering agent or agents in a concentration sufficient to provide or maintain a pH in the solution or fluid of from about 9.0 to about 12. In a preferred embodiment, the invention relates to a well treatment or fracturing fluid of the type described wherein the buffering agent comprises a weak acid and an ammonium or alkali metal salt of a weak acid, the acid and salt being selected to provide a pH of the fluid between 9.0 and 11. In a most preferred embodiment, the invention relates to a fracturing fluid composition comprising an aqueous hydrated borate crosslinked galactomannan gum solution containing a buffering agent, the buffering agent being present in the solution in an amount sufficient to provide the fluid with a pH of from about 9.0 to about 12. As used herein, the term "well treatment" refers generally to operations undertaken with respect to a well and formation, including, but not limited to, fracturing and sand control, while the term "galactomannan gum" is understood to include mixtures of such gums.
In a further embodiment of the invention, the invention relates to a method of treating a subterranean formation penetrated by a borehole, comprising injecting into the borehole and into contact with the formation, at a rate and pressure sufficient to treat the formation, a fluid composition comprising an aqueous hydrated metal crosslinked galactomannan gum solution buffered to a pH of from about 9.0 to about 12. Preferably, the fluid is injected at a pressure sufficient to fracture the formation. More particularly, the invention relates to a method of treating or fracturing characterized by use of a fluid of the galactomannan gum type wherein the buffering agent comprises a weak acid and an ammonium or alkali metal salt of a weak acid, the acid and salt being selected to provide a pH of the fluid of solution between about 9.0 and about 12. In a preferred embodiment, the galactomannan gum is borate crosslinked, and buffering agent is present in the solution in an amount sufficient to provide or maintain the fluid with a pH of from about 9.0 to about 12.
Finally, the invention relates to a process for preparing a fluid of the type described. According to this embodiment of the invention, galactomannan gum is dissolved or suspended in a neutral or acidic aqueous solution to form hydrated galactomannan gum. A crosslinking metal releasing agent and a buffering agent or agents, in a concentration sufficient to provide or maintain a pH in the solution or fluid of from about 9.0 to about 12, are then combined with the hydrated gum, simultaneously, or in any order, to form an aqueous hydrated metal crosslinked galactomannan gum solution buffered to a pH of from about 9.0 to about 12. As used herein, the term "crosslinking metal releasing agent" is taken to designate those metal or metal containing materials which will provide a metal ion or metal containing species in the solution capable of crosslinking the galactomannan gum. Temperatures employed are ambient or greater.
DETAILED DESCRIPTION OF THE INVENTION
As indicated, the fluid compositions of the invention comprise an aqueous hydrated metal crosslinked galactomannan gum solution. Preferred solutions are those derived from guar, hydroxypropyl guar, or carboxymethylhydroxypropyl guar, and mixtures thereof. Initially, the hydrated metal gum solutions may be formed by providing the gum compositions in solid powder form, or as a suspension in a hydrocarbon liquid (e.g., diesel or kerosene) and blending with a neutral or acidic aqueous solution, the hydrate forming a gel. As indicated, it is a surprising advantage of the invention that reduced concentrations of the hydrated crosslinked gum may be employed in the fluid. Preferably, the concentrations of the hydrated metal crosslinked gum will be below 25 pounds per 1000 gallons, being most preferably from about 10 pounds to 25 pounds per 1000 gallons, it being understood that higher amounts may be employed. Superior advantages accrue at levels of from 10 to 22 pounds per 1000 gallons of fluid.
Any suitable crosslinking metal ion, metal containing species, or mixture of such ions and species may be employed. Accordingly, as used herein, the term "metal crosslinked" is understood to include crosslinking attributable to certain metal containing species, such as borate ion. The crosslinking ions or species may be provided, as indicated, by dissolving into the solution compounds containing the appropriate metals, or by other means. Exemplary metal ions or metal containing species include those of boron, zirconium, and titanium, supplied from compounds such as boric acid, sodium borates, boron oxide, zirconium oxide, and titanium oxide. The concentration of added crosslinking metal releasing agent is dependent on factors such as the temperature and the amount of thickening agent employed, and will normally range from about 5 ppm to about 100 ppm, preferably from about 10 ppm to about 60 ppm. It is an important advantage of the invention that higher levels of the crosslinking metal ion or metal containing species may be employed, thereby insuring improved crosslinking. While cross-linking may be virtually immediate, a slight delay thereof, e.g., up to twenty seconds or so, may actually be preferred in the field since it allows mixing and pumping of the precursor solution through surface equipment, formation of the composition being feasible on the fly.
Any buffering agent or combination of such that will provide or maintain the solution at the necessary pH required may be employed. Thus, the combination of a weak acid and its salts may be employed, so long as the pH of the solution is maintained in the range mentioned. For example, the corresponding acid and ammonium and alkali metal phosphates, carbonates, bicarbonates, sesquicarbonates, acetates, or mixtures thereof may be used. Ammonium, potassium, and sodium carbonates, bicarbonates, sesquicarbonates and hydrogen phosphates are preferred as buffer salt components. For pH values toward the upper end of the range specified, combinations of alkali metal hydroxide and appropriate weak acid salt may be employed. For example, a buffer comprising a base such as NaOH IOH and a weak acid salt such as Na 2 H 2 PO 4 may be used. Proportioning of the buffer components of the combinations to achieve the desired pH is well within the ambit of those skilled in the art. As will be appreciated by those skilled in the art, other additives commonly employed in fracturing solutions, such as breakers, clays, etc., must be selected so that they do not significantly reduce the pH of the solution. As indicated, the pH required in the various embodiments of the invention ranges from about 9.0 to 11, preferably from about 9.5 to about 10. The amount of buffer required is, of course, an effective amount, i.e., an amount sufficient to maintain the desired pH, given the additives and other components of the fluid. Preferably, this amount will not exceed 50 pounds per 1000 gallons of fluid, most preferably, not more than about 20 pounds per 1000 gallons of fluid.
In order to illustrate the invention more fully, the following procedures were performed.
Base fluids comprising fifteen pounds and twenty pounds of guar respectively per 1000 gallons of fresh water, optionally containing KCl or similar salt, were prepared, and the guar in each was allowed to hydrate. The fluids also contained minor amounts of normal, non-active (from the standpoint of crosslinking activity) fracturing fluid additives such as a surfactant, a biocide, and a defoamer. These fluids were used in the tests reported hereinafter. Sodium sesquicarbonate and sodium carbonate were added as a buffering agent to each base fluid in the amount of 12 pounds and 5 pounds, respectively, per 1000 gallons. Finally, boric acid, as a 3.5 percent by weight solution in water, based on the weight of the water and acid, was mixed with each of the base fluids containing the buffer to give a concentration of 1.5 pounds of boric acid per 1000 gallons. Borate crosslinking of the guar was effected within 5 to 20 seconds.
To demonstrate the suitability of the fluids for fracturing, viscosity tests were performed. The conditions of and results of the tests are given in the tables below. Table I reports results with the 15 pound solution, while Table II reports results with the 20 pound solution. In both tables, viscosity results are rounded to the nearest 5th unit.
TABLE I______________________________________ Viscosity, 100 sec.sup.-1 (cp)Temperature lnitial Final (3 hours)______________________________________1) 100° F. 135 1202) 125° F. 140 1103) 150° F. 140 105______________________________________
TABLE II______________________________________ Viscosity, 100 sec.sup.-1 (cp)Temperature lnitial Final (3 hours)______________________________________1) 100° F. 350 2752) 125° F. 370 2553) 150° F. 290 2504) 175° F. 285 180______________________________________
As those skilled in the art will be aware, upon completion of fracturing, removal or breakdown of the fluid in the fracture is important, compositions called breakers (e.g., ammonium persulfate or peroxide) being employed to assist in such. The retained conductivity of the formation after such withdrawal and/or breakdown is an important measure of fracturing fluid efficiency. Accordingly, standardized retained conductivity tests were run on two fluids according to the invention, utilizing a combination breaker system, the fluids containing 15 pounds (A) and 20 pounds (B), per 1000 gallons, respectively, of hydrated borate crosslinked galactomannan gum thickener. Each fluid was buffered with 12 pounds of sodium sesquicarbonate and 5 pounds of sodium carbonate. Proppant type was 20/40 Badger sand at a concentration of 2 lbs/sq.ft. A two percent by weight KCl solution was used as a base line solution. Results are shown in Table III.
TABLE III______________________________________ Final Percent Breaker Closure Polymer Conduc- RetainedTemp lbs/ Pressure Cone tivity Conduc-Fluid°F. 1000 gal. (psi) lbs/1000 gal (Darcy) tivity______________________________________2% 125 0 2000 -- 216 --KClA 125 2.5 (Tot.) 2000 159 130 60B 125 3.0 (Tot.) 2000 188 106 49______________________________________
Static fluid coefficients for fluids according to the invention were determined utilizing standard fluid loss coefficient procedures. Results are shown in Table IV.
TABLE IV______________________________________Fluid Temp. Permeability Cw Spurt(lbs/1000 gal) °F. (md) (ft/min.sup.1/2) (gal/100 ft.sup.2)______________________________________15 100 0.76 0.0017 1.8215 125 0.77 0.0018 0.1515 150 0.73 0.0023 5.1720 100 0.77 0.0014 0.020 125 0.80 0.0016 0.020 150 0.71 0.0013 0.020 175 0.80 0.0032 0.0______________________________________
These results clearly demonstrate the suitability of the low concentration borate crosslinked guar solution, buffered according to the invention, for use as a fracturing fluid.
In the manner described, supra, a fracturing fluid was prepared containing, per 1000 gallons, 10 pounds of guar, 1.5 pounds of boric acid, and 5 pounds each of sodium bicarbonate and sodium carbonate. Viscosity of solution at 90° F. was 170 sec-1 with greater than 100 cp. This further experiment demonstrates the ability of the borate-buffer combination to crosslink very reduced concentrations of galactomannan gum.
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The invention, in one embodiment, is a novel fracturing fluid composition comprising an aqueous metal hydrated galactomannan gum, buffered to a pH of from about 9 to about 11. In another embodiment, a method of fracturing a formation is disclosed, the method being characterized by the use of the compositions mentioned.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to ceramics, and more particularly to improving the properties of ceramic zirconia.
2. Description of the Previously Published Art
Because of its toughness, wear resistance, hardness, low thermal conductivity, and other properties, zirconia (ZrO 2 ) has found numerous ceramic applications. Typical of these uses (e.g., in gasoline or diesel engines) are wear buttons for valve tappets; valve seats; oxygen sensor sleeves; piston caps (for diesels), and precombustion chamber elements (for diesels). Typical non-auto engine uses include grinding balls, dies, check valves and the like.
Zirconia competes with or has replaced other ceramics for the above uses.
In all of the above uses the zirconia is prepared in a particular crystal morphology, viz., in tetragonal form. There are three commonly occurring and established crystal forms of zirconia: cubic, tetragonal, and monoclinic. Cubic is the normal form at high temperature. The tetragonal form can exist at room temperature, but is metastable and under stress tends to transform to the monoclinic form, with increase in volume and loss of various important properties. The form of zirconia desired for practically all the above mentioned ceramic end uses is the tetragonal. However the tetragonal in the unstabilized form, unfortunately, tends to convert to the less desirable monoclinic form, even on standing at room temperature. This conversion is also grain size dependent, the larger the grain size the easier the transformation. Transformation may be quite rapid under stress unless the zirconia is pre-stabilized in some way. It is of course also temperature dependent.
Various modifications and/or treatments of zirconia have been tried in efforts to minimize conversion of tetragonal to the monoclinic form. One approach is to use extremely fine zirconia powder such as less than 200 Angstrom units as reported in Jour. Phys. Chem, 69, 1238 (1965). Another approach is to add one or more stabilizers. The addition of yttria (Y 2 O 3 ) and ceria (CeO 2 ) to stabilize the tetragonal zirconia system has been reported in Jour. Mat. Sci., 20, 3988-3992 (1985). In U.S. Pat. No. 4,753,902 zirconia is stabilized with two components. The first is from 5 to 45 mole percent titania. The second can be either (a) up to 10 mole percent of rare earth oxide, (b) up to 7 mole percent yttria or (c) up to 20 mole percent ceria.
3. Objects of the Invention
It is an object of the invention to provide a stabilized tetragonal zirconia which is cost effective. These properties include improved flexural strength, low temperature stability, fracture toughness, and hardness; improved resistance to thermal shock, abrasion and erosion; and others.
It is a further object to stabilize ceramic zirconia with dysprosia, ceria, and a third component which is either yttria or titania.
It is also an object to provide shaped zirconia ceramics of superior thermal and mechanical properties.
These and further objects will become apparent as the description of the invention proceeds.
SUMMARY OF THE INVENTION
The present invention is directed towards lowering the cost by addition of small amounts of a three component stabilizer to tetragonal zirconia which comprises a mixture of dysprosia (Dy 2 O 3 ), ceria, and a third stabilizer which is either yttria or titania. The stablized zirconia composition on a molar basis is made of (A) between 0.3-1.3 percent dysprosia; (B) between 7.0-8.5 percent ceria; (C) a third stabilizer which is either (i) between 0.5-0.8 percent yttria; (ii) between 0.8-1.5 percent titania; or (iii) mixtures of (i) and (ii) containing up to a combined total of 2.3 percent; and (D) the balance making 100 percent being zirconia in the tetragonal form as determined by Xray diffraction. When ceramic zirconia is used industrially for its toughness and low thermal conductivity, it is preferred that the zirconia be in its tetragonal crystalline form. It is this form which presents the most desirable properties including fracture resistance. The stress around a crack tip tends to convert tetragonal zirconia into the monoclinic form, impeding the crack growth and hence resulting in toughening of the system, which is the so-called "stress-induced transformation". We have found that the combination of the stabilizers, Dy 2 O 3 , CeO 2 , and Y 2 O 3 and/or TiO 2 , in the specified amounts when added to the zirconia system lowers the tetragonal to monoclinic transformation temperature so that the tetragonal phase is retained at room temperature. Thus it is the multiple effect in appropriate combination of Dy 2 O 3 and CeO 2 with either Y 2 O 3 or TiO 2 which is utilized to retain the tetragonal phase at room temperature.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
As recognized by one skilled in the art, the preferred starting particle size of ZrO 2 powder is a tradeoff between finer sizes for increased reactivity sintering and larger sizes for easier powder handling during processing. In the case described herein, the ZrO 2 powder preferably has an average particle size below about 20,000 Angstrom units since the smaller, more reactive particle size aids sintering. For zirconia particles sizes below 200 Angstrom units the present stabilizer system may become somewhat less effective, since material this fine is fairly stable anyhow as discussed in the J. Phys. Chem. article. It may be noted that zirconia at 200 Angstrom units, so far as is known, is not available commercially in non-agglomerated form. Thus the zirconia average particle size above 200 Angstrom units is preferred. Zirconia powder which is commercially available as agglomerates averaging less than about 1.0 micron in size is a preferred material. In such commercial powders, the zirconia is in the monoclinic form, except for the finest particles, which may be in the tetragonal form. On sintering, the stabilizers diffuse into the zirconia and it changes to the tetragonal form.
Sources of yttria, dysprosia, and ceria include the preferred nitrates as well as other soluble salts such as oxalates, acetates, chlorides, etc. Also, the stabilzers can be added simply as oxides, in which case the calcination step to decompose the salts can be omitted. Solvents for the stabilizers in salt form include the preferred low cost water as well as other solvents such as isopropyl alcohol, acetone, etc. When all the materials are in the oxide form, their solubility becomes irrelevant, and the liquid simply becomes a dispersion medium.
Zirconia can be admixed with the other ingredients in any conventional high shear mixer. It is preferred to have the slurry mixture carry at least about 70 weight % solids loading.
Substantially any conventional process may be used for drying the slurry mixture such as a roto drier, a spray drier, a freeze drier, etc.
When the stabilizers are added in salt form, the calcining temperature used to decompose the salts may vary in the range of from about 500° to 800° C.
The ZrO 2 powder, which has either a calcined salt, dried oxide or a mixture, is milled for a period of time sufficient to provide complete homogeneity. The milling time will also depend on the particle size desired in the product. For a ZrO 2 with an initial particle size in the range of about 6 down to 1 microns, a preferred milling time is in the range 8-12 hours.
The dry powder can be pressed into greenware shapes for sintering, e.g., at pressures of 8,000-15,000 psi as conventionally used.
Sintering is the final step, and this should be carried out in a furnace with the product exposed to air, at about 1430°-1500° C. for about 1-3 hours, and preferably about 1465°-1475° C. for about 2-3 hours. Higher temperatures could be used, but the grain size would adversely increase.
In addition to the dysprosia and ceria stabilizer, the third component stabilizer utilized is either yttria or titania or a mixture of these two stabilizers containing up to a combined total of 2.3 mole %. Also, additional stabilizers known in the art such as MgO may be added in minor amounts such as up to 2 mole percent with the three component stabilizer of this invention. Table 1 below illustrates the ranges for the stabilized ZrO 2 compositions.
TABLE 1______________________________________Stabilized Zirconia Compositions Mole PercentIngredient Broad Range Preferred Range______________________________________Dysprosia 0.3-1.3 0.3-1.0Ceria 7.0-8.5 8-8.5Yttria or Titaniaa. Yttria 0.5-0.8 0.5-0.6b. Titania 0.8-1.5 .9-1.0______________________________________ Zirconia in tetragonal form, balance to make 100 mole percent.
Having described the basic aspects of the invention, the following examples are given to illustrate specific embodiments thereof.
EXAMPLE 1
This example describes the preparation of a stabilized zirconia composition according to the present invention.
The following ingredients were assembled:
ZrO 2= 111.76 g, 90.7 mole percent, average particle size about 0.5 micron.
Y 2 O 3 =129 g, 0.5 mole percent (from Y(NO 3 ) 3 )
Dy 2 O 3 =1.12 g, 0.3 mole percent (from Dy(N03) 3 )
CeO 2 =14.6302 g, 8.5 mole percent (from Ce(NO 3 ) 4 )
The nitrates were mixed in 300 ml water with stirring until completely dissolved. The monoclinic zirconia powder (Z-Tech Corp. New Hampshire) was then added to the solution, and the slurry was thoroughly mixed in a 1/2-liter plastic jar with 1/2 inch alumina balls. The slurry was then dried under a heat lamp to form a powder. The powder was calcined at 650° C. for 1 hour to decompose the nitrates to the oxide form. The calcined powder was milled in a ball mill for 8 hours, and the processed powder was dry-pressed into a ceramic shape (0.24×0.15 inch cross section) and sintered in a furnace in air at 1465° C. for 3 hours.
EXAMPLE 2-6
Examples 2-6 were carried out by the same general procedure of Example 1 with the ingredients set forth in Table 2 below.
EXAMPLE 7
The products from Examples 1 to 6 were analyzed using conventional test procedures described below with the results reported in Table 2.
Flexural strength. Four-point bend test. The specimens/bars were tested under the following conditions:
Span: Inner=0.5". Outer=1.0".
Cross head speed: 0.02 in/min.
Width of the bar (approx.)=0.1900 inches.
Thickness of the bar (approx.)=0.1300 inches.
Machine: Instron.
Low temperature stability: This test is performed in an autoclave maintained at 200° C. The water vapor pressure was 100 psi (this was generated by addition of approximately 3-4 ml of water at room temperature). The samples were held under the above conditions for 250 hours. The testing for degradation in strength was done using a dye penetrant and later tested for flexural strength.
Fracture toughness: This was measured using the indentation and the pre-notched beam technique. The experiments were done at 10-20 kg load.
Hardness: Vickers hardness was measured using 1 kg load.
Thermal shock. The theory of thermal shock evaluation is described by Hassellman in J. Amer. Ceram. Soc., Vol 52, No. 11 pages 600-604 (1969). Following Hassellman's technique the samples were heated to the desired temperature and equilibrated at that temperature for ten minutes before they were instantaneously quenched into the room temperature bath (at 25° C.) which was agitated vigorously when the sample was placed in the bath to maintain the bath at its constant temperature. The difference between the heated temperature and the room temperature quench is reported as the delta temperature in the thermal shock valve in Table 2 through which the sample survived.
Erosion test. Six zirconia specimens sit on a rotating disk in a chamber. No. 36 SiC grit is blasted at the disk at 50 psi, at a 2 inch distance from samples. Comparisons were made to commercially available ceramic materials.
Thermal expansion: An Orton Dilatometer was used.
TABLE 2______________________________________Influence of Stabilizers on ZirconiaMole PercentIngredient Ex. 1 Ex. 2 Ex. 3 Ex. 4 Ex. 5 Ex. 6______________________________________ZrO.sub.2 90.7 91.0 88.7 90.0 90.1 90.5Dy.sub.2 O.sub.3 0.3 1.0 0.8 0.5 0 0.5Y.sub.2 O.sub.3 0.5 0 0 0 0.9 0CeO.sub.2 8.5 7.0 8.0 8.0 7.0 8.0TiO.sub.2 0 1.0 1.5 1.5 0 1.0MgO 0 0 0 0 2.0 0Flexural 120 107 102 105.3 95.0 120.0strength,ksiLow Temp. Excel- Excel- Excel- Excel- Weak Excel-stability lent lent lent lent lentFracture 8-toughness, 10.5 9.6 n/a n/a 7.5 n/aMPa m.sup.1/2Hardness,Kg/mm.sup.2 1050 1050 n/a n/a n/a n/aThermalshock °C. 300 300 n/a n/a 300 n/aAbrasion Excel- Excel- n/a n/a n/a n/aresistance lent lentErosion Excel- Excel- n/a n/a n/a n/aresistance lent lentThermal 11.0 11.0 n/a n/a 11.0 11.0expansionx10.sup.-6 /°C.______________________________________ n/a = not available
Table 2 shows the general over-all improvement to a zirconia shape provided by stabilizers according to the present the invention. Examples 1-4 and 6 demonstrate the invention. Example 5 is a control and shows the result when one of the three required stabilizers is omitted, in this case, dysprosia. Note that the omission results in destabilization as seen by the weak low temperature stability for Example 5.
From a comparison Examples 1-3, it is seen that yttria enhances the flexural strength. From a comparison of Examples 1 and 5 it is seen that dysprosia enhances fracture toughness and low temperature stability. Ceria, from other studies, has been found to enhance the low temperature stability.
It is understood that the foregoing detailed description is given merely by way of illustration and that many variations may be made therein without departing from the spirit of this invention.
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Ceramic tetragonal zirconia is stabilized against transformation to the undersirable monoclinic form by incorporation of a mixture of stabilizers comprising controlled amounts of dysprosia and ceria, together with either yttria or titania (or both). The mixture can be prepared by wet-mixing zirconia with nitrates of the stabilizer materials, followed by drying, then calcining, e.g., at 650° C. to drive off decomposition products, and then sintering at, e.g., 1465°-1475° C.
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BRIEF SUMMARY OF THE INVENTION
The invention relates to the use of bretazenil, also known as t-butyl (S)-8-bromo-11,12,13,13a-tetrahydro-9-oxo-9H-imidazo-[1,5-a]pyrrolo[2,1-c][1,4]benzodiazepine-1-carboxylate, of the formula ##STR2## to induce sleep corresponding largely to natural sleep in the treatment of sleep disorders. In another aspect, the invention relates to the use of bretazenil for the preparation of medicaments for the treatment of sleep disorders and a method and medicament for the treatment of sleep disorders are further objects of the present invention.
BACKGROUND OF THE INVENTION
Bretazenil is a known substance. Its preparation is described, for example, in European Patent Publication No. 59 391 which is incorporated herein by reference. The anticonvulsive and anxiolytic properties of this compound are also described in this publication.
Bretazenil has a high affinity to the benzodiazepine receptor (BZR), the modulatory part of the receptor for the amino acid GABA. GABA is an inhibiting messenger (neurotransmitter) of certain nerve cells (neurons) of the brain. The release of GABA by one type of neuron causes inhibition of the excitability of other neurons, which can manifest itself, for example, in anxiolytic, anticonvulsive, muscle relaxant or sedative-hypnotic activity. Three main types of substances have been found which bind to the BZR and which are denoted as ligands: (1) The agonists, which intensify the inhibition by GABA; (2) the so-called inverse agonists which reduce the activity of GABA; and (3) the antagonists which do not influence the activity of GABA, but which prevent its intensification or reduction by agonists or inverse agonists at the BZR (see Haefely, W., Handbook of Anxiety 3: 165-188, 1990). Substances from the three groups of ligands which are active on the BZR generally have a high affinity to this receptor, but differ by the so-called relative intrinsic effectiveness, i.e. the capability of influencing the activity of GABA. While pure antagonists occupy the BZR, but do not influence the activity of GABA, full agonists or inverse agonists produce maximum intensification or reduction of the inhibiting activity of GABA at the BZR. It is conceivable that between the extremes there are substances with different degrees of intrinsic effectiveness and that such substances would also be found. These substances behave as weak agonists or inverse agonists, but significantly weaker than the activity of the actual full agonists. Such substances are therefore partial agonists or partial inverse agonists.
It has now been found that bretazenil is one such partial agonist or partial agonist at the BZR. In animal experiments it has been established that bretazenil has a high affinity to the BZR, but bretazenil only achieves effects which correspond to those of lower dosages of benzodiazepines (BZD), for example, diazepam. The characteristic effects and side-effects of increasing dosages of a BZD such as sedation, muscle relaxation, ataxia and amnesia could not be shown or could be shown only in subtoxic dosages for bretazenil in classical animal experiments.
It has now surprisingly been found that bretazenil can induce sleep in healthy, male and female volunteers even in low dosages and that the induced sleep corresponds largely to natural sleep.
DETAILED DESCRIPTION OF THE INVENTION
The invention relates to the use of bretazenil, also known as t-butyl (S)-8-bromo-11,12,13a-tetrahydro-9-oxo-9H-imidazo-[1,5a]pyrrolo[2,1-c][1,4]benzodiazepine-1-carboxylate, of the formula ##STR3## to induce sleep corresponding largely to natural sleep in the treatment of sleep disorders, e.g. hypersomnias, relative insomnias, circadian dysfunction, parasomnias, REM sleep behavior disorder, sleep walking and sleep terrors.
The sleep inducing property of bretazenil can be determined on the basis of the double blind study described hereinafter:
Six male volunteers and six female volunteers with an average age of 24 years and an average weight of 58 kg took part in the study. The volunteers were required to take 0.5, 1 or 2 mg of bretazenil in tablet form after 21 hours. This took place after the volunteers had taken identical placebo tablets on two previous evenings. The second placebo night served as the reference (pre-control). Placebo was again administered on the evening of the day after bretazenil (post-control). The volunteers spent the four nights of one session in a sleep laboratory. Their brain current curves (EEG) and body movements were recorded on magnetic tape and thereafter evaluated using a computer. This method permits the exact recording of the sleep profile.
The results determined in this study (see Table I) show quite clearly that bretazenil was effective in all tested dosages. Bretazenil shortened drastically the time needed to fall asleep (sleep latency) and lengthened the total sleep per night by lengthening the normal sleep (non REM sleep), and reducing the number of intermittent short waking phases. Likewise, bretazenil reduced the number of body movements during sleep. Thus, bretazenil brought about a more rapid falling asleep and a lengthening and stabilization of the sleep. During normal sleep bretazenil either did not reduce the deep sleep stages 3 and 4 or reduced these stages only insignificantly, but overall it did lengthen the duration of the middle sleep stage 2. Middle sleep stage 2 is characterized by the appearance of so-called sleep spikes in the EEG pattern. The number of sleep spikes was, however, unaltered. However, the number of K complexes, another characteristic pattern in the EEG, was reduced in stage 2. These K complexes can be traced back to disturbing acoustic signals which reach the sleeping brain. The reduction of K complexes therefore, points to a deepening of the sleep. The superficial sleep of stage 1 was shortened by bretazenil.
The sleep of a healthy human being is usually structured in five sleep cycles with each cycle being terminated with a dream phase. Bretazenil does not alter the number of cycles, but lengthens both the first cycle and the period until the first dream phase occurs (REM sleep latency). The dream sleep, also referred to as REM sleep because rapid eye movements occur therein, was, however, only immaterially shortened overall by bretazenil. The closeness of the rapid eye movements (REMs) in the REM sleep was decreased.
TABLE I______________________________________Effects of bretazenil on the sleep of healthy volunteers Dosage administered in mg p.o. 0.5 1 2______________________________________Sleep latency 33* 30* 20*Total sleep +45 min* +44 min* +45 min*Intermittent waking phases 32* 25* 22*Movements 80* 74* 69*Non REM sleep +60 min* +60 min* +62 min*Stage 1 98 65* 79Stage 2 130* 128* 136*Stage 3 90 90 87Stage 4 87* 103 79*Spikes in stage 2 101 107 107K complexes in stage 2 71* 63* 61*Duration of first sleep 154* 189* 198*cycleREM sleep latency 165* 206* 217*REM sleep duration 91 83 85REMs in REM sleep 84 49* 31*______________________________________
All values, except total sleep and non REM sleep, are in % and relate to the pre-control. The absolute increase in minutes is given for total sleep and non REM sleep.
*p<0.05
In the practice of the invention, bretazenil can be used in the form of pharmaceutical preparations for peroral, rectal and parenteral administration. Tablets, coated tablets, dragees, hard and soft gelatine capsules, suppositories, solutions, emulsions or suspensions are examples of such preparations. Perorally administrable forms, especially tablets, are preferred dosage forms.
Bretazenil is processed with pharmaceutically inert, inorganic or organic carrier materials in order to manufacture pharmaceutical preparations. Although not intended to be an exhaustive list, examples of suitable carrier materials for tablets, coated tablets, dragees and hard gelatine capsules are, for example, lactose, maize starch or derivatives thereof, talc, stearic acid or its salts and the like. Vegetable oils, waxes, fats, semi-solid and liquid polyols and the like are, for example, suitable for soft gelatine capsules. Natural or hardened oils, waxes, fats, semi-solid and liquid polyols and the like are, for example, suitable for suppositories. Suitable carrier materials for the manufacture of solutions, emulsions and suspensions are, for example, water, polyols, saccharose, invert sugar, glucose and the like.
Moreover, the pharmaceutical preparations can contain the usual preservatives, solubilizers, stabilizers, wetting agents, emulsifiers, sweeteners, colorants, flavorants, salts for varying the osmotic pressure, buffers, coating agents and/or antioxidants.
As already mentioned, bretazenil can be used in the treatment of sleep disorders. The dosages can vary according to the severity of the sleep disorders and the age and weight of the patient and will, of course, be fitted to the individual requirements in each particular case. In general, in the case of peroral administration a dosage of about 0.25 to about 5 mg should be appropriate.
The following Example describes a dosage form which is suitable for the practical application of the present invention. It is, however, in no way intended to limit the scope of the present invention.
______________________________________Example (tablet)______________________________________Bretazenil 0.5 mgLactose 126.5 mgMaize starch 54.0 mgPolyvinylpyrrolidone 8.0 mgSodium carboxymethylstarch 10.0 mgMagnesium stearate 1.0 mgTablet weight 200.0 mg______________________________________
Bretazenil, the lactose and the maize starch are mixed and granulated with an aqueous solution of polyvinylpyrrolidone. The dried and pulverized granulate is mixed with the sodium carboxymethylstarch and the magnesium stearate, whereupon the mixture is pressed to tablets having a weight of 200 mg.
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The compound t-butyl (S)-8-bromo-11,12,13,13a-tetrahydro-9-oxo-9H-imidazo[1,5-a]pyrrolo[2,1-c][1,4]benzodiazepine-1-carboxylate of the formula ##STR1## can be used for the preparation of medicaments for the treatment of sleep disorders and also as a medicament for the treatment of sleep disorders.
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BACKGROUND OF THE INVENTION
The invention relates to a road marking unit comprising a housing with a light-transmitting window. The invention also relates to a road marking system.
Such a road marking system is known from GB 2 159 559. In the known road marking unit, light waveguides constructed as glass fibers are provided in the housing, first ends of said waveguides being directed towards the window and second ends thereof being optically coupled to a light source or to a reflector. Such a road marking unit may serve to distinguish individual driving lanes of a road from one another. It is desirable to have a possibility to render the road marking unit visible or invisible in dependence on the ambient conditions. The known road marking unit, in which the second ends of the light waveguides are coupled to a light source, can be made visible or invisible in the case of weak ambient light in that the light source is switched on or off. During the day, in particular in direct sunlight, however, the ambient light is so strong that it drowns out the light originating from the road marking unit. It is not possible then to influence the visibility of the road marking unit.
SUMMARY OF THE INVENTION
It is an object of the invention to provide a road marking unit of which the visibility in direct sunlight can be influenced. According to the invention, an electro-optical switch is accommodated in the housing, which in an activated state reflects light from the window back towards the window, and in a deactivated state of the road marking unit absorbs light from the window. The road marking unit will reflect more light in proportion as there is more ambient light in the activated state, so that the road marking unit will be visible also in strong ambient light, such as direct sunlight. In the deactivated state, the light traversing the window is absorbed, so that the road marking unit is clearly less visible.
The electro-optical switch may be connected to a supply and to switching means arranged at a distance from the road marking unit by means of a cable. In a favorable embodiment of the road marking unit according to the invention, a receiver for remote control of the electro-optical switch is accommodated in the housing, and, in addition, a solar cell is arranged in the housing for supplying power to the receiver and the electro-optical switch. An external cable is redundant in this embodiment, which simplifies the installation of the road marking unit.
The ambient light itself, originating from the sun or from headlights of a vehicle, may suffice to cause the road marking unit to light up and to render it visible. In an attractive embodiment of the road marking unit according to the invention a light generator is present in the housing. This renders it possible to cause the road marking unit to light up also while ambient light is absent. The light generator may comprise a light source accommodated in the housing, for example a semiconductor light source such as a light emitting diode, or a discharge lamp, for example a low-pressure discharge lamp such as a low-pressure mercury discharge lamp. In an attractive modification of this embodiment, the light generator comprises a first end of at least one light waveguide, which waveguide is optically coupled to a light source at a second, opposed end. The light source itself may be positioned at a distance from the road marking unit, so that this light source can be easily replaced, for example at the end of its useful life.
It is favorable in this modification when a transparent plate is arranged in a plane defined by the window, which plate is provided at an inward-facing surface with a relief having transverse surfaces which extend substantially perpendicularly to the plane defined by the window, while first ends of light waveguides are directed towards said transverse surfaces. It is possible by these means to generate a directional light beam, so that a good visibility of the road marking unit is realized with a comparatively low power.
The visibility of road marking units may be impaired by snow. An embodiment of the road marking unit according to the invention provided with a heater element renders it possible to melt away the snow locally. This also renders it possible to use components in the road marking unit which would not function at low temperatures.
It is noted that the state of the road marking unit need not correspond to the state of the optical switch. For example, an optical switch may be used which reflects in its deactivated state. The road marking unit would be in the activated state then.
The invention also relates to a road marking system provided with one or several road marking units according to the invention, with a control system for the road marking units, and with means for coupling the road marking units to the control system. The means for coupling the one or several road marking unit(s) to the control system may be constructed as a cable for the conduction of electrical or optical signals. In a modification, the coupling means are constructed as a remote control connection in the form of a transmitter/receiver pair, the transmitter transmitting control signals from the control system to a receiver accommodated in the road marking unit.
The electro-optical switch comprises, for example, an electrochromic material. In a practical embodiment, the electro-optical switch is provided with an electro-optical medium on the basis of liquid crystals. Such an electro-optical switch has a long life and is comparatively inexpensive. Depending on the type, optical properties of the electro-optical medium are influenced by means of an electric field. The electro-optical medium may comprise, besides the liquid crystals, also embedded substances such as coloring agents. Use is made, for example, of optical properties which can be influenced, such as the rotation of polarization, double refraction, dispersion, absorption, selective reflection. An overview of electro-optical switches provided with electro-optical mediums in the form of liquid crystals can be found, for example, in "Reflective LCDs for Low-Power Systems", T. Uchida, SID 96 Digest 96, pp. 31-34.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a first embodiment of a road marking unit according to the invention,
FIG. 1A shows a detail of a component of the road marking unit of FIG. 1,
FIG. 2 shows a second embodiment,
FIG. 3 shows a third embodiment,
FIG. 3A shows a detail of a component of FIG. 3,
FIG. 3B shows a detail of a further component of FIG. 3,
FIG. 4 shows a fourth embodiment,
FIG. 5 shows a modification of the fourth embodiment in a cross-section taken on the line V--V in FIG. 4, and
FIG. 6 shows a road marking system according to the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows a road marking unit 1 comprising a housing 10 with a light-transmitting window 20. The road marking unit 1 is accommodated in a road surface a. An electro-optical switch 30 is accommodated in the housing 10 opposite the window 20. The electro-optical switch 30 reflects light emanating from the window towards the window 20 when the road marking unit is in an activated state. In a deactivated state of the road marking unit 1, the electro-optical switch 30 absorbs light traversing from the window 20. In the embodiment shown, the electro-optical switch 30 is provided with an electro-optical medium on the basis of liquid crystals. The electro-optical switch is shown in more detail in FIG. 1A. The electro-optical switch 30 shown is provided with a first and a second polarizer 31, 35, a first and a second support 32, 34 for a light-transmitting material, for example glass or a synthetic resin such as polyethylmethacrylate, and an electro-optical medium 33 comprising liquid crystals. A reflector, constructed as a reflecting layer 36 here, is provided at the surface 30a facing away from the window. The reflecting layer 36, made of aluminum in this case, at the same time serves as an electrode. It is possible to apply an electric field across the electro-optical medium 33, influencing optical properties thereof, by means of this reflecting electrode 36 and a further, light-transmitting electrode 37, for example constructed as a layer of tin-doped indium oxide. The electro-optical medium 33 operates in the twisted nematic mode in this case.
With the road marking unit 1 in the activated state p the electro-optical switch 30 will reflect light, for example sunlight, incident on the window 20, so that it is thrown back to the exterior again through the window 20. The road marking unit 1 is visible then. When the road marking unit 1 is in the deactivated state a however, the electro-optical switch will absorb light incident thereon through the window 20. The road marking unit then becomes visible.
The window 20 is provided with a protective layer 21, for example made of urethane resin or araldite, re-inforced with glass fibers. This gives the road marking unit 1 a rough upper surface, which promotes road safety. The protective layer 21 scatters the light thrown to the exterior, so that it is visible across a wide spatial angle.
The embodiment of the electro-optical switch 30 as shown can be operated by remote control. A receiver 50 is for this purpose arranged in the housing 10, which receiver brings the optical diaphragm 32 of the electro-optical switch 30 into its light-reflecting (activated) state or light-absorbing (de-activated) state. The receiver 50 is supplied by a battery 61 which is charged by means of a solar cell 60.
The housing 10 is constructed here as a box having walls 11 and a window 20. An alternative possibility is to encapsulate the components 30, 50, 60 and 61 of the road marking unit in a translucent material, for example a synthetic resin, which material then constitutes the housing.
FIG. 2 shows a second embodiment of the road marking unit according to the invention. Components therein corresponding to those in FIG. 1 have reference numerals which are 100 higher. The road marking unit of FIG. 2 has an electro-optical switch 130 which differs from that in FIG. 1 in that the reflecting electrode 36 is replaced by a light-transmitting electrode. A reflecting coating on an inner surface of the housing 110 here forms a reflector 136. A light generator 140 is in addition present in the embodiment shown. The light generator 140 here is a first end 142 of a light waveguide 141 which is arranged between the electrooptical switch 130 and the reflector 136. The light waveguide 141 is optically coupled to a light source 144 at its second, opposed end 145.
The electro-optical switch 130 transmits light when the road marking unit of FIG. 2 is in its activated state p. Light incident on the window 120 from the exterior in this state is reflected back to the exterior by the reflector 136. The light is absorbed in the electro-optical switch 130 when the road marking unit 101 is in the deactivated state. Since the light generator 142 is arranged between the reflector 136 and the electro-optical switch 130 in this embodiment, light originating from the light generator 142 is also absorbed in the deactivated state. This has the advantage that road marking units whose light waveguides are coupled to the same light source may still have mutually differing states.
In a third embodiment shown in FIG. 3, components have reference numerals which are 100 higher than those of corresponding components in FIG. 2. A transparent plate 223 lying in a plane 222 defined by the window 220 forms part of the road marking unit of FIG. 3, which plate is provided with a sawtooth relief at its inward-facing surface. This relief is shown in more detail in FIG. 3A. The sawtooth relief has transverse surfaces 225 with an orientation which is substantially perpendicular to the plane 222 defined by the window 220. This plane 222 is substantially parallel to or coincides with the surface a of the road. A light generator is present between the window 220 and the electro-optical switch 230 in the embodiment of FIG. 3. The light generator 240 here comprises first ends 242 of light waveguides 241 directed towards the transverse surfaces 225 of the relief. The light waveguides 241 are optically coupled to a light source (not shown) by means of their second, opposed ends.
The electro-optical switch 230 of the road marking unit of FIG. 3 is shown in more detail in FIG. 3B. Components therein corresponding to those in FIG. 1A have reference numerals which are 200 higher. The electro-optical switch 230 in FIG. 3B is provided with an electro-optical medium 233 on the basis of liquid crystals. The electro-optical medium 233 operates in the polymer dispersed liquid crystal mode (PDLC). The electrodes 236 and 237 are made of a light-transmitting material. A light-absorbing material 238 is provided on the electrode 236.
When the road marking unit 201 is in the activated state, the electro-optical medium 233 reflects light incident thereon through the window 220, so that the road marking unit 201 is visible. The visibility of the road marking unit 201 can be further enhanced under bad lighting conditions in that the light source coupled to the light waveguides 241 is switched on. In the deactivated state of the road marking unit 201, the electro-optical medium 233 transmits light incident thereon through the window 220, thus achieving that the light is absorbed by the absorbing layer 238, so that the road marking unit 201 is less visible.
A fourth embodiment is shown in FIG. 4. Components therein have reference numerals which are 100 higher than those of corresponding components in FIG. 3. The road marking unit shown has an electro-optical switch which operates in the PDLC mode, as does that in FIG. 3. The light-absorbing layer of the electro-optical switch, however, is provided on an inner surface of the housing 310, separately from the other components, in this case. The first end 342 of the light waveguide 341 is here arranged between the window 320 and the electro-optical switch 330.
FIG. 5 shows a modification of the fourth embodiment of the road marking unit 401 according to the invention, in which light sources 444 and 444', for example low-pressure mercury discharge lamps, are accommodated in the housing 410. Components in FIG. 5 corresponding to those of FIG. 4 have reference numerals which are 100 higher.
FIG. 6 shows a road marking system provided with first road marking units 101 according to the invention, with a control system 170 for the road marking units, and with means 180 for coupling the first road marking units 101 to the control system 170. The road marking system is further provided with second road marking units 101' and with means 180'for coupling the second road marking units 101' to the control system 170. The means 180 and 180' here comprise cables for the conduction of electrical signals.
It will be obvious that within the scope of the invention many variations are possible to those skilled in the art.
The invention is embodied in each now characteristic and each combination of characteristics.
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A road marking unit (1) according to the invention comprises a house (10) with a light transmissive window (20). In the house (10) is arranged an electro-optic switch (30). In an activated state of the road marking unit (1) the electro-optic switch (30) achieves that light is reflected from the window (20) back to the window (20). In a de-activated state of the road marking unit (1) the electro-optic switch (30) achieves that light from the window (20) is absorbed. The road marking unit (1) of the invention has the advantage that it can also in bright environmental light it can be switched between visible and invisible.
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RIGHTS OF THE GOVERNMENT
The invention described herein may be manufactured and used by or for the Government of the United States for all governmental purposes without the payment of any royalty.
BACKGROUND OF THE INVENTION
This invention relates to energetic organic compounds. In one aspect, this invention relates to gem-dinitro precursor alcohols. In another aspect, it relates to azidodinitro compounds. In a further aspect, it relates to methods for preparing these compounds.
Energetic organic compounds have a long history of use in explosives and propellants. Examples have included polynitroaromatic compounds such as 2,4,6-trinitrotoluene (TNT); cyclic nitramines such as 1,3,5-trinitrazacyclohexane (RDX) and 1,3,5,7,- tetranitrazacyclooctane (HMX); and nitrate esters such as nitrocellulose (NC) and nitroglycerin (NG). Despite some shortcomings in terms of their thermal stability and sensitivity, these materials have seen heavy use during the past century.
More recently, considerable attention has been paid to various polynitro aliphatic compounds. Compounds, such as bis(2,2-dinitropropyl) formal/acetal (BDPNF-A) and bis(2,2,2-fluoridinitroethyl) formal (FEFO), have found widespread use as energetic plasticizers in modern explosive and propellant formulations.
Yet another promising class of compounds is the group of azido and azidonitro aliphatic compounds. Despite their well deserved reputation as sensitive materials, organic azides are potentially useful ingredients in energetic formulations because the azido group contributes 80 to 90 kcal/mol, while not detracting from the O/C ratio of the molecule. Incorporating both azido and polynitro functionalities in the same molecule generally has been accomplished by joining individual polynitroalkyl and azidoalkyl moieties via a non-energetic linkage. Examples include azidoalkyl esters of polynitroacids such as 1,3-diazido-2-propyl 4',4',4'-trinitrobutyrate (DAPT) and azide-terminated nitramines such as 1,7-diazido-2,4,6-trinitrazeheptane (DATH) and 1,5-diazido-3-nitrazapentene (DANPE). A more compact combination of these two functionalities would be the use of the azidodinitromethyl group in place of trinitromethyl and fluorodinitromethyl groups, which have been incorporated previously in propellant ingredients.
It is an object of the present invention to provide novel azidodinitro compounds.
It is another object of this invention to provide a method for preparing novel azidodinitro compounds.
It is yet another object of this invention to provide novel gem-dinitro alcohols.
It is a further object of this invention to provide a method for preparing gem-dinitro alcohols.
Other objects, aspects and advantages of the present invention will be readily apparent to those skilled in the art from a reading of the following detailed disclosure.
SUMMARY OF THE INVENTION
In accordance with the present invention there is provided the compound 4,4-dinitro-1-butanol and a method for making same which comprise reacting trinitromethane and acrolein at a reduced temeprature to provide 4,4,4-trinitrobutyraldehyde, reducing the butyraldehyde to provide the corresponding alcohol, and reducing the alcohol.
Also provided is the compound 4-azido-4,4-dinitro-1-butyl acetate and a method for preparing same which comprises reacting 4,4-dinitro-1-butanol with acetyl chloride to provide the corresponding ester, and reacting the ester with an alkali metal azide in the electrolysis cell.
There is further provided the compound 4-azido-4,4-dinitro-1-butanol and a method for preparing same which comprises reacting 4-azido-4,4-dinitro-1-butyl acetate with methanol and recovering the aforesaid azidodinitro alcohol.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
4,4-dinitro-1-butanol is prepared according to the scheme shown below. ##STR1##
The addition of trinitromethane to acrolein (Reaction I) is conducted at a temperature of about -10° to +10° C. in aqueous medium. Stoichiometric quantities may be employed, although it is presently preferred to employ a slight excess of acrolein. After the addition is complete, the solution may be allowed to warm to room temperature. The organic phase is separated from the aqueous phase and the aqueous phase is extracted with a suitable solvent, such as, for example, methylene chloride. The combined organic layers are washed with water, separated, dried and concentrated to yield the aldehyde.
The reduction of the aldehyde to 4,4,4-trinitro-1-butanol (Reaction II) is conducted at a reduced temperature of about 0° to 10° C. in alcoholic solution by the portionwise addition of sodium borohydride to the aldehyde solution. After the addition is complete, the solution may be allowed to warm to room temperature. The solution may be stirred for 2 to 12 hours to ensure complete reaction. Following removal of the solvent, the remaining material is hydrolyzed with a suitable acid, then extracted with a suitable solvent, such as methylene chloride. The extracts are washed successively with water, a weak basic solution and water, then dried and concentrated to yield the trinitroalcohol.
The conversion of 4,4,4-trinitro-1-butanol to 4,4-dinitro-1-butanol (Reaction III) is conducted by stirring the trinitro alcohol is a suitable alcoholic medium with an excess of KI at room temperature for 1 to 10 days or about 2 to 24 hours at an elevated temperature. The precipitated potassium salt is filtered. suspended in water, acidified, and then extracted with a suitable organic solvent. The extracts are neutralized, dried and concentrated to yield the dinitro alcohol.
The azidodinitro compounds of this invention are prepared according to the following scheme.
HC(NO.sub.2).sub.2 CH.sub.2 CH.sub.2 CH.sub.2 OH+ClCOCH.sub.3 →HC(NO.sub.2)CH.sub.2 CH.sub.2 CH.sub.2 O.sub.2 CCH.sub.3 (IV)
HC(NO.sub.2).sub.2 CH.sub.2 CH.sub.2 CH.sub.2 O.sub.2 CCH.sub.3 +NaN.sub.3 →N.sub.3 C(NO.sub.2).sub.2 CH.sub.2 CH.sub.2 CH.sub.2 O.sub.2 CCH.sub.3 (V)
The 4,4-dinitro-1-butyl acetate is prepared (Reaction IV) by treating a solution of 4,4-dinitro-1-butanol in a suitable solvent, such as methylene chloride, with about 10 to 30 percent excess acetyl chloride. After complete addition of the acetyl chloride, the resulting mixture is stirred at room temperature for 30 to 120 minutes. The mixture is then quenched with cooled water, separated, dried and concentrated to yield the desired dinitro acetate.
Conversion of the 4,4-dinitro-1-butyl acetate to the correspondingazido dinitro compound (Reaction V) is accomplished by charging the dinitro compound together with aqueous sodium azide and an electrolyte, such as NaOH, to the anode compartment of a divided electrolysis cell, charging aqueous soidum azide to the cathode compartment of the cell and applying a current to the cell. After a suitable reaction period, the reaction is stopped and the anolyte extracted with a suitable solvent, such as methylene chloride. The extract is then washed, dried and concentrated to yield the desired product.
The following examples illustrate the invention.
EXAMPLE I
4,4,4-Trinitrobutyraldehyde
A 12 L three-necked, round-bottom flask with a thermometer, mechanical stirrer, and 1000 ml addition funnel was charged with 6377 g of an 11% aqueous trinitromethane solution (701.5 g; 4.675 mol) and cooled in a dry-ice bath at 9° C. A solution of acrolein (274.1 g, 4.90 mol) in 2000 ml of water was added at a rate that maintained the temperature at 0° C. The dry-ice bath was removed and the stirred solution allowed to warm to room temperature overnight. The two phases were separated and the aqueous layer was extracted with CH 2 Cl 2 (2×2000 ml). The combined organic layers were washed with water (2×2000 ml). The product was dried (MgSO 4 ) and concentrated to give 878 g (91%) of the aldehyde as a yellow oil; n D =1.4731 (26C). The infrared spectrum showed bands at 1725 cm -1 (C═O), 1590, 1300, and 800 cm -1 (NO 2 ).
EXAMPLE II
4,4,4-trinitro-1-Butanol
Crude 4,4,4-trinitrobutaldehyde (878 g, 4.24 mol) was dissolved in methanol (1000 ml) and cooled in an ice bath while NaBH 4 (130.7 g, 3.44 mol) was added portion-wise. The mixture was stirred at room temperature overnight under a nitrogen purge which removed much of the solvent. The thick suspension was hydrolyzed with 6 N HCl (approx. 41) and the product extracted with CH 2 Cl 2 (3×1000 ml). The extracts were washed with water (1000 ml), saturated NaHCO 3 (2×1000 ml), and water (1000 ml). The product solution was dried over anhydrous MgSO 4 and concentrated to yield 554 g (63%) of a yellow oil, n D =4735 (19C). The infrared spectrum showed peaks at 3619, 3370, 2950, 2890, 1595, 1305, 1058 and 801 cm -1 .
EXAMPLE III
4,4-Dinitro-1-Butanol
This alcohol was prepared by stirring 4,4,4-trinitro-1-butanol (554 g, 2.65 mol) in methanol (6 l) with KI (1426 g, 8.6 mol) for 6 days at room temperature. The precipitated potassium salt was filtered, suspended in water (4 L), acidified with concentrated HCl (250 ml), and extracted into CH 2 Cl 2 (6×500 ml). The extracts were washed with 10% NaHSO 3 (1000 ml). The solution was dried over anhydrous MgSO 4 and concentrated to give the product (220 g, 51%) as a yellow oil. The infrared spectrum had peaks at 3450, 2950, 1575, 1340, and 1070 cm -1 .
EXAMPLE IV
4,4-Dinitro-1-Butyl Acetate
This ester was synthesized by treating a solution of 4,4-dinitro-1-butanol (39.2 g, 0.24 mols) in CH 2 Cl 2 (100 ml) with acetyl chloride (22 ml, 24 g, 0.31 mol). After 90 minutes at room temperature, the reaction was quenched with ice water. Separation, drying (MgSO 4 ), and concentration of the organic phase gave the product (42.7 g, 87%) as a light yellow oil; n D =1.4574 (24C). The infrared spectrum of the product had peaks at 2960, 1745, 1575, 1245, and 1060 cm -1 . Elemental analyses-Calculated for C 6 H 10 N 2 O 6 : C, 34.95; H, 4.85; N, 13.59; Found: C, 35.17; H, 4.83; N, 12.95.
EXAMPLE V
4-Azido-4,4-Dinitro-1-Butyl Acetate
A divided electrochemical H-cell was charged with 4,4-dinitro-1-butyl acetate (10.2 g), 30% aqueous NaN 3 (25 ml) and 12N NaOH (4 ml) in the anode compartment and 30% NaN 3 (35 ml) in the cathode compartment. This solution was electrolyzed at 650 mA using a platimum foil anode (6.5 cm 2 ) and a stainless steel cathode. After 5.25 h the reaction was stopped, and the anolyte was extracted with CH 2 Cl 2 (3×25 ml). Brine-washing, drying, and concentrating the extracts yielded a product which displayed a weak hydroxyl absorption in the infrared spectrum. The product was reacetylated by stirring with acetyl chloride (1 ml) in CH 2 Cl 2 (30 ml) for 2 h. This reaction was quenched in ice water, dried, and concentrated. The crude yellow oil was purified by column chromatography on silica gel eluting with 10% ethyl acetate in hexanes. The purified product was a clear light yellow oil which was greater than 95 % pure by HPLC: n D =1.4649 (25C); IR: 2165, 1735, and 1590 cm -1 ; NMR (CDCl 3 ): 4.07 (q, 2H), 2.58 (m, 2H), 2.07 (s, 3H), 1.73 (m, 2H). Elemental analyses calcluated for C 6 H 9 N 5 O 6 : C, 29.15; H, 3.64; N, 28.34. Found: C, 29.59; H, 3.90; N, 27.89.
Various modifications may be made without departing from the spirit of the invention or the scope of the appended claims.
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Provided herein are the compounds 4,4-dinitro-1-butanol, 4-azido-4,4-dinitro-1-butyl acetate and methods for preparing each compound.
4,4-dinitro-1-butanol is prepared by reacting trinitromethane with acrolein, reducing the resulting trinitroaldehyde to provide the corresponding alcohol and reducing the alcohol.
4-azido-4,4-dinitro-1-butyl acetate is prepared by reacting 4,4-dinitro-1-butanol with acetyl chloride to yield the corresponding acetate and reacting the acetate with an alkali metal azide in an electrolysis cell.
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FIELD OF INVENTION
The present invention relates to fluid filters and particularly relates to an oil filter made up of two elements that may be detached one from the other.
BACKGROUND AND SUMMARY OF INVENTION
In many internal combustion engines it is desirable to filter the engine oil with two different types of filters, a full flow filter and a partial flow filter. The full flow filter is series connected to the oil circuit of the engine so that all of the oil circulating through the engine passes through the full flow filter, while the partial flow filter is connected to the oil circuit so that it receives a portion of the oil flowing through the engine. Typically, the partial flow filter is connected in parallel with a bypass device that carries a portion of the oil around the partial flow filter, and since the partial flow filter is not required to filter the full oil flow, it is usually designed to filter smaller particles from the oil as compared to a full flow filter.
At present, full flow and partial flow filters in an internal combustion engine are usually installed as separate filters which requires separate mounting systems and separate plumbing to invade the oil circuit of the engine in two different places. In some internal combustion engines it is difficult to provide sufficient space for two separate filters, and the hardware and labor needed to mount the second filter adds expense to the engine.
While present systems for providing full flow and partial flow filters are adequate, it would be preferred to use a single filter that would equal the performance of the two filter system. To achieve this goal, the present invention provides a filtering system in which two filters are detachably attached together and function as a single unit requiring only one mounting system on the engine. In a preferred mode, one of the filters would be a full flow filter, and the other would be a partial flow filter.
In accordance with the present invention, an oil filter is provided for attachment to an engine filter base having an engine outlet for transmitting oil under pressure to the filter and having an engine inlet for receiving oil from the filter. The filter includes a first can defining a first filter chamber having first and second ends. A first inlet receives oil into the first end of the first can, and a first outlet transmits oil from the first end of the first can. A second inlet receives oil into the second end of the first can, and a second outlet transmits oil from the second end of the first can. A second filter can defines a second filter chamber and includes a third inlet and a third outlet for receiving oil into and transmitting oil from the second can. First attachment apparatus is provided for detachably attaching the first end of the first can to the engine filter base and for sealably interconnecting the engine outlet with the first inlet and the engine inlet with the first outlet of the first can. A second attachment apparatus is provided for detachably attaching the second can to the second end of the first can and for sealably interconnecting the second outlet to the third inlet and the second inlet to the third outlet. First and second filter elements are disposed, respectively, in the first and second cans and a first flow directing device directs the oil flow in the first can from the first inlet to the second outlet and from the second inlet to the first outlet. This first flow directing apparatus is operable to direct at least some of the oil flow through the first filter element as the oil flows through the first can. A second flow directing means directs oil flow within the second can from the third inlet, at least partially through the second filter element and to the third outlet. In this construction, a single filter is constructed of two separable cans containing filter elements, either of which may be a full flow or a partial flow filter.
The oil filter of the present invention offers the performance and separation of two separate filters, a full flow filter and a partial flow filter, and yet it has the convenience and engine mounting simplicity of a single filter. The separability of the two filter cans allows a user to replace or clean the individual filter cans at different times and results in a more versatile overall filter. This separability also enables the convenient use of a permanent filter element in one can and a disposable filter element in the other can, if desired. For example, a truck engine will be operated in many different environments and the filter will be required to remove different quantities of particulates and water depending upon the environment. If few particulates are encountered in the oil, but the water content of the oil is high, the partial flow filter, which is usually designed to remove the water, may need changing more frequently. However, if the oil contains many large particles, but little water, the opposite result may occur, and the full flow filter must be changed more frequently. The separability of the two filter cans of the present invention allows either of the filters to be replaced or cleaned as needed.
The present oil filter also offers human engineering advantages. While the filter handles and fits the engine as a single filter, the owner can see that he has two filter cans, representing two filters to the owner, and he can easily take them apart. Since the filters are positioned in a side-by-side engaging relationship within the engine compartment, they will be exposed to the same environment and a visual inspection of the side-by-side filters will normally enable one to determine which filter was most recently installed. It is easy for the owner to visually inspect to insure that a mechanic has replaced the correct one of the filters. Thus, while the separability of the two filter cans provides functional advantages from a purely mechanical viewpoint, it also provides psychological or human engineering advantages.
While the invention in its preferred form has been described above as an oil filter for a truck, it will be understood that this filter can be used in a wide variety of fluid filtering applications.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention may best be understood by reference to the following Detailed Description of Preferred Embodiments when considered in conjunction with the drawings in which:
FIG. 1 is a somewhat diagrammatical cross-sectional view of a filter having two filter cans threadedly attached together that function as one filter and constitute one from of the present invention;
FIG. 2 is a diagrammatical cross-sectional view of an alternate embodiment illustrating a different oil flow path through two filter cans;
FIG. 3 is another cross-sectional view of an alternate embodiment similar to that shown in FIG. 2 and having an additional bypass valve.
DETAILED DESCRIPTION
Referring now to the drawings in which like reference characters designate like or corresponding parts throughout the several views, there is shown in FIG. 1, a filter 10 embodying one form of the present invention. The filter 10 includes a first filter can 12 and a second filter can 14 that may be threadely attached together, but in FIG. 1 they are shown spaced apart and in position for being screwed together.
The first can 12 is constructed with cylindrical sidewalls 16 with an upper end plate 18 mounted on one end of the cylindrical wall 16 and a lower end plate 20 mounted within the cylinder of the cylindrical wall 16 and proximate to the lower end of the cylindrical wall 16. Both of the end plates 18 and 20 are circular in shape and are dimensioned to mate with the cylindrical sidewalls.
A cylindrical sealing ring 20 is mounted on the outside face of the upper end plate 18 adjacent to the perimeter of the plate, and a plurality of inlet parts 22 are formed in the upper plate 18 at positions inwardly from the sealing ring 21. A threaded aperture 24 is formed in the center of plate 18. This aperture 24 constitutes an oil outlet for the can 12 and it also functions to threadedly secure the first can 12 to an internal combustion engine or another source of oil.
To illustrate how the first can 12 is connected to a source of oil, an engine oil filter base 26 is shown immediately above the can 12. This base includes a cylindrical mounting face 28, preferably circular in shape, and a threaded nipple 32 extending outwardly from the center of the mounting face 28. Oil outlet ports 30 are disposed concentrically around the nipple 32, and nipple also functions as an oil inlet.
The first can 12 is threadedly secured to the engine filter base by inserting the nipple 32 into the threaded aperture 24 and rotating the can 12 until the sealing ring 20 engages the face 28 of the engine filter base 26. It will be appreciated that the oil outlet ports 30 are positioned so that they will be disposed inwardly from the sealing ring 21 when the first can 12 is attached to the filter base 26. Thus, the sealing ring 21 forms a seal around the oil outlet ports 30 and the inlet ports 22 of the first can 12. A washer or other sealing means is provided so that the threaded interconnection between nipple 32 and threaded aperture 24 forms a seal as well. In this configuration, oil may flow out of the engine through oil port 30 and into the first can 12 through the oil inlet ports 22. Also, oil flows from the first can 12 back to the engine base 26 by flowing through and out of the threaded aperture 24 and into the threaded nipple 32.
A tube 34 extends downwardly from the threaded aperture 24 into the can 12 where an interior can 36 is mounted on the tube 34 within the can 12. The volume defined between the cylindrical sidewalls 16 and the interior can 36 constitutes a cylindrical passageway 38, and outlet ports 40 are formed in the lower and plate 20 so that oil may flow into the can 12 through the inlet ports 22, through the passageway 38 and through the outlet ports 40. A second tube 42 is concentrically disposed within the can 12 and extends through the center of the plate 20. The outer end of the tube 42 is threaded and forms a threaded nipple 44 which will hereinafter be described in greater detail. The second tube 42 extends into the can 36 and terminates at a lower plate 46. Apertures 48 are formed in the tube 42 within the interior can 36 so that oil may flow from the tube 42 out of the apertures 48 and around the lower plate 46. A radial flow filter element 48 is mounted between the lower plate 46 and against an upper plate 50. The upper tube 34 extends downwardly through the upper plate 50 and terminates at the lower plate 46, and apertures 52 are formed in the tube 34 at positions between the upper and lower plates 46 and 50. Thus, oil may flow radially from the interior of can 36, through the radial flow filter element 49 and into the tube 34 through the apertures 52. The oil flowing into the tube 34 will then exit the first can through the threaded aperture 24 and the threaded nipple 32.
Apertures 54 are also formed in the tube 34 above the upper plate 50 but still within the interior can 36. These apertures are normally closed by a bypass valve 56 that is mounted within the can 36 on the tube 54. A spring 58 controls the bypass valve 56 so that it is normally closed and blocks the flow of oil through the apertures 54. However, if the oil pressure within the can 36 relative to the oil pressure within the tube 34 exceeds a predetermined amount, the bypass filter will open and allow oil to flow from the interior of the can 36 through the apertures 54 and into the tube 34. Under these conditions, the bypass valve 56 will maintain a predetermined pressure drop between the interior of the can 36 and the interior of the tube 34 so that at least a portion of the oil may continue to flow through the filter element 48 and into the tube 34. In this construction, the filter element 49 may be chosen to filter fine particles and it need not be required to carry the full flow of the oil that is being circulated through the engine. Also, the bypass valve 56 performs a safety function in that it will allow oil to bypass the filter element 49 in the event that it becomes completely clogged.
Referring to the lower portion of the first can 12, it will be appreciated that a sleeve portion 60 is formed by the cylindrical walls 16 at a position below the lower end plate 20. Mounted within the sleeve portion 60 is an O-ring 62 that helps form the seal with the second can 14. Located immediately below the first can, there is shown in FIG. 1, a second can 14 that includes cylindrical sidewalls 64 an upper end plate 66 covering the top end of the cylindrical sidewall 64 and a curved lower endplate 68 closing the bottom end of the cylindrical sidewall 64. The upper plate 66 includes a flange 70 that extends around the periphery of the plate 66 and has a curved annular recess 71 formed therein for receiving the O-ring 62. When the second can 14 is mounted on the first can 12, it fits within the sleeve portion 60 and the O-ring 62 is received into the recess 71 and forms a seal between the flange 70 and the interior of the sleeve portion 62. An annular sealing ring 72 is also mounted on the top of the flange 70 and it functions to engage and seal against the lower surface of the plate 20.
At the center of the plate 66 is a threaded aperture 74 that is dimensioned to receive the threaded nipple 44. This arrangement is essentially identical to the threaded aperture 24 and threaded nipple 32. Again, a washer or similar sealing device is used to form a seal between the threaded aperture 74 and nipple 44.
Disposed between the threaded aperture 74 and the sealing ring 72 are inlet ports 76 formed in the plate 66. These ports 76 allow oil to enter the second can 44 from the outlet ports 40 that are formed in plate 20 of the first can 12. A central tube 78 extends downwardly into the second can 14 and a filter 80 is mounted on the tube 78. The filter 80 includes an upper plate 82 and a lower plate 84 with the filter media extending therebetween. The tube 78 extends through the upper plate 82 and terminates at the lower plate 84, and a bracket 86 is provided for supporting the lower plate 84 on the curved plate 68. Apertures 88 are formed in the tube 78 as it passes through the filter 80 so that oil may flow from the outside of the filter 80 through the filter and into the apertures 88. Apertures 90 are formed in the tube 78 above the upper plate 82 and these apertures are controlled by a bypass valve 92 that is essentially identical to the valve 56. The function of bypass valve 92 is to allow oil to escape from the second can 14 if the filter 80 is completely clogged.
Referring now to the top portion of FIG. 1, in operation, oil flows from the engine through ports 30 in the oil filter base 26 and into the first can 12 through the inlet ports 22. The oil then flows through the passageway 80, around the interior can 34, and out of the first can 12 through the outlet ports 40. The oil from ports 40 enters the second can 14 through inlet ports 76 and then flows around the upper plate 82 and through the filter 80 and the apertures 88 into the center tube 78. The filtered oil exits the second can 14 through the threaded aperture 74 and the threaded nipple 44 and enters the tube 42. This filtered oil exits the tube 42 through apertures 48 and flows around the lower plate 56 and into and through the filter 48 and the apertures 52. After the oil flows through the apertures 52, it has entered the tube 34 and it exits the second can 12 through the threaded aperture 24 and threaded nipple 32 as it returns to the engine filter base 26. An alternate route for the oil to follow within the interior can 36 is through the bypass valve 56. If for any reason the full flow of the oil cannot pass through the filter 48, the oil pressure differential between the interior of the can 36 and the interior of the tube 34 will rise to the point that the bypass valve 56 will open and allow at least some of the oil to pass through the apertures 54. In like manner, when the pressure differential between the interior of the second can 14 and the interior of the tube 42 rises to a predetermined level, the bypass valve 92 will open and allow oil to flow from the interior of the can 14 through the apertures 90 and into the tube 42.
While radial flow filters have been shown in the embodiment illustrated in FIG. 1, it will be understood that numerous different types of filters may be used. For example, axial flow filters could be mounted in one or both of cans 12 to 14. Likewise, it is preferred, but not necessary, that the oil be filtered in the second can 14 prior to being filtered in the first can 12. Also, in the above description, the terms "upper" and "lower" were used only in reference to the position of structure as shown in the drawings. The filter 10 could assume any orientation in use.
In FIG. 2, there is shown a filter can 100 that can be substituted for the first filter can 12 shown in FIG. 1. Can 100 is constructed similarly to can 12 in terms of outward appearance. However, internally, the oil within can 100 flows through filter 48 before it is delivered to the second can 14. In the can 100 there is no interior can 36 and the oil is allowed to enter can 100 through the ports 22 and immediately flow through the filter 48. At the center of the filter 48 there is a tube 102 having a plurality of apertures 104 formed therein. A second tube 106 is disposed coaxially within the tube 102 and the oil flowing through the apertures 104 is received into the volume defined between the two tubes 102 and 106. Tube 102 terminates and is sealed against the upper plate 50 but it extends through the lower plate 46. The inner tube 106 extends through and is sealed against both plates 50 and 46. The oil flowing through tube 102 enters a receptacle 108 having a plurality of apertures 110 formed therein, the oil flows through the receptacle 108 and 110 aperture into an annular chamber 112 defined by walls 114, and then the oil flows out of the outlet ports 40 and is available to be filtered by the second can 14.
FIG. 3 illustrates a filter can 116 that is essentially identical to that of filter can 100. except that a bypass valve 118 is disposed at the bottom of the can. This bypass valve 118 allows the oil to flow directly to the second can, such as can 14, without flowing through the filter 48 when a predetermined pressure differential exists between the interior of the can 116 and the interior of the tube 110. The bypass valve 118 is a safety measure in that it will allow the oil to flow out of the can 116 even when the filter 48 is completely clogged and it also allows the use of a partial flow filter within can 116 if desired.
Although particular embodiments have been described in the foregoing detailed description, it will be understood that the invention is capable of numerous rearrangements, modifications and substitutions of parts without departing from the scope of the invention as defined in the following claims.
Of the embodiments described above, filter 10 is preferred, and it is prefered to provide a partial flow in can 12 and a full flow filter in can 10. However, in all of the embodiments, two cans are separable and, as described above, this structure results in significant mechanical and human engineering advantages.
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An oil filter attaches to an internal combustion engine and filters the oil that is circulated through the engine. The filter includes a first can and a second can that may be attached together or separated apart. The first can attaches to the engine, and it has a first inlet and a first outlet for receiving oil from and transmitting oil to the engine. It also has a second inlet and a second outlet for receiving oil from and transmitting oil to the second can. The second can sealably attaches and detaches from the first can and, when attached, the second outlet of the first can is connected to an inlet of the second can, and an outlet of the second can is sealably connected to the second inlet of the first can. Filters are disposed within the two cans and flow directing apparatus is provided to direct the oil from the engine, through the two filters in series and back to the engine.
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BACKGROUND OF THE INVENTION
This invention relates to a pressure or differential pressure measuring device wherein a deformation of a flexible sensing disk, such as metallic diaphragm in response to a pressure is detected, and more particularly, to a new disk material and a device for supporting the flexible disk for use in the pressure or differential pressure measuring device.
Conventionally, a substantially rigid metal ring is used to fixedly secure the sensing diaphragm to the housing. The peripheral end of the diaphragm is connected to the metal ring by welding, however, in this case the initially flat diaphram may be corrugated or the tension exerted thereon may not be uniform due to thermal expansion caused by the welding. These drawbacks should be eliminated in order to permit desirable operation of the diaphragm.
In order to obviate these drawbacks, a conventional differential pressure measuring device, shown in FIG. 1, includes a differential pressure detecting portion 1 formed in a generally cylindrical frame, and also provided are a first housing 2 and a second housing 3, into which insulating materials 4 and 5 made of glass or ceramic are filled. Each inner axial surface of the insulating materials is in a hemi-spherical shape to which metal foils 6 and 7 are secured to function as capacitor plates. The first and the second housings 2 and 3 are symmetrically formed to confront the metal foils with each other. Contacting portions of these housings 2 and 3 are provided with annular ridges 9 and 91, and annular grooves 10 and 101 having wedge-like cross section. Inner contacting portions of these housings are provided with conical recesses 110 and 111 having a height d. A sensing diaphragm 8 is interposed between the housings 2 and 3 and is fixed thereto at the ridge portions 9 and 91 by welding. A first measuring chamber 11 is determined by a space defined between the spherical surface of the first insulation 4 and the measuring diaphragm 8, and a second measuring chamber 12 is determined by a space defined between the spherical surface of the second insulation 5 and the sensing diaphragm 8. The differential pressure detecting portion 1 is supported by first and second casings 13 and 14 both of which are tightly secured to each other by fixing bolts 15 and 15. First and second pressure chambers 18 and 19 are provided between the first casing and the first insulation and between the second casing and the second insulation, respectively. An input pressure is introduced into a first measuring chamber 11 through a hole 16 formed in the first casing 13, the first pressure chamber 18 and a bore 20 formed in the first insulation 4, and a second input pressure or reference pressure is introduced into a second measuring chamber 12 through a hole 17 formed in the second casing 14, the second pressure chamber 19 and a bore 21 formed in the second insulation 5.
When a pressing force P is applied to the first and the second housings 2 and 3 by fastening the first and second casings 13 and 14 together by means of the bolts 15, since the peripheral ends of the housings 9 and 91 are tapered, the peripheral ends are urged radially outwardly due to the pressing force P, to reduce the height d while increasing the diameter of the ridge portion so that tensile stress is applied to the sensing diaphragm radially outwardly to thereby eliminate non-uniform or local tension of the diaphragm.
With this structure, the supporting plates 15 and 16 and a plurality of bolts 17 around the periphery thereof are required, so that a compact structure is not obtainable. Further, the thermal expansion coefficient of the housings 2 and 3, made of stainless steel, is 17×10 -6 to 18×10 -6 , whereas the thermal expansion coefficient of the supporting plates 15 and 16 and the bolts 17 made of steel is 10×10 -6 to 11×10 -6 , so that the clamping force may be changed with changing temperature due to the relatively large difference of the thermal expansion coefficient, resulting in the degradation of the sensing characteristic of the diaphragm.
Another method of assembling the pressure measuring device has been proposed wherein the sensing diaphragm is welded to the outer peripheral surface of the housings 2 and 3 while maintaining a predetermined tension. However, such a method is disadvantageous in that the diaphragm may be deformed due to the welding, so that it would be rather difficult to obtain a sensing diaphragm to which stable and uniform tension is applied.
SUMMARY OF THE INVENTION
It is therefore an object of this invention to overcome the above-mentioned drawbacks and to provide an improved pressure measuring or differential pressure measuring device wherein uniform tension is applied to the sensing diaphragm.
Another object of this invention is to provide an economical and compact device which is easily handled and the operation of which is stable over a long duration.
Briefly, and in accordance with the present invention, the sensing diaphragm is made of precipitation hardenable metal which is contracted by heat treatment, and which has high resiliency. The sensing diaphragm is fixed to the housings and then subject to aging treatment and tension is uniformly applied to the entire diaphragm upon completion of the aging treatment. Alternatively, in order to eliminate the need for the casings and securing bolts, a fixing plate of precipitation hardenable material may be secured to the outer periphery of the sensing device and then subjected to an aging or heat treatment by which it is contracted.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:
FIG. 1 shows a cross-sectional elevation according to the conventional differential pressure sensing device;
FIG. 2 shows a cross-sectional elevation of the essential part of a sensing device according to one embodiment of the present invention;
FIG. 3(A) is graphical representation showing the thermal expansion of the precipitation hardenable metal with time;
FIG. 3(B) is a graphical representation showing temperature change of the metal with time;
FIG. 4 shows a cross-sectional elevation according to a second embodiment of the present invention;
FIG. 5 shows a cross-sectional elevation taken along the line V--V in FIG. 3;
FIG. 6 is a schematic view showing the application of a third embodiment of the present invention to a device for measuring liquid level.
DETAILED DESCRIPTION OF THE INVENTION
The present invention will now be described in detail with reference to FIG. 2 wherein like parts and components are designated by the same reference numerals and characters as those shown in FIG. 1.
A differential pressure sensing portion 22 includes a generally cylindrical first housing 24 and a second housing 25 each having a space therein. First and second insulating materials 4 and 5 are filled in the spaces of the housings 24 and 25, respectively, and the inner surfaces of these insulations are spherically concave and are provided with metal foils 6 and 7 to function as capacitor plates. A sensing diaphragm 23 is interposed between the housings 24 and 25, the peripheral ends of which secure the peripheral end of the sensing diaphragm 23 by welding.
The material of the sensing diaphragm 23 according to the present invention is precipitation hardenable metal having high resiliency, such as
(a) product name "Elinver" consisting of Ni by weight of 36%; Cr, 12 wt%; Mn, 1 to 2 wt%; W, 1 to 3 wt%, Si, 1 to 2 wt%; C, 0.8 wt%; and Fe, the remainder.
(b) product name "thermelast" consisting of Co by weight of 40%; Ni, 26 wt%; Cr, 12 wt%; Mo, 4 wt%; W, 4 wt%; Ti, 1 wt%; Mn, 1.4 wt%; Be, 0.2 wt%; and the remainder Fe.
(c) product name "Elgiloy" consisting of Co by weight of 40%; Ni, 15 wt%; Cr, 20 wt%; Mo, 7 wt%; Mn, 2 wt%; Be, 0.04 wt%; C, 0.15 wt%; and the remainder Fe.
(d) product name "Nickel-Span C" consisting of Ni by weight of 42%; Cr, 5.3 wt%; Mn, 0.5 wt%; Si, 0.3 wt%; Ti, 2.4 wt%; Al, 0.4 wt%; Cu, 0.05 wt%; C, 0.02 wt%; and the remainder Fe.
(e) product name "KRN" consisting of Co by weight of 40%; Ni, 15 wt%; Cr, 20 wt%; Mo, 7 wt%; Mn, 1.5 wt%; Si, 0.45 wt%; Be, 0.05 wt%; Cu, 0.15 wt%; and the remainder Fe.
In precipitation hardenable metals having high resiliency as above, intermetallic compounds are precipitated in crystals to contract the total volume after the metal is subjected to aging treatment at high temperatures ranging from about 500° to 600° C. for one hour.
According to the present invention the above aging treated precipitation hardenable metal is employed as the sensing diaphragm 23.
Referring now to FIGS. 3(A) and 3(B), and initially to FIG. 3(B), the precipitation hardenable metal is heated to the temperature of 600° C. starting from a room temperature (of 20° C.). The high temperature is maintained for about one hour (t o ) and then reduced to the room temperature. In this case, as shown in FIG. 3(A), the metal having an initial length of l 1 is thermally expanded for the corresponding time t o . Thereafter the length of the metal is reduced to have a length l 2 when the metal is cooled to room temperature. The length l 2 is shorter than l 1 as shown in length differential Δl. Δl is experimentally obtained and is approximately 0.1 to 0.2% of the length l 1 .
Therefore, in the present invention such contraction is utilized to tension the diaphragm in the pressure detecting portion 22. That is, the precipitation hardenable metal is firstly fixed to the first and second housings 24 and 25, and thereafter subject to aging treatment and, as explained above, tension is applied to the metal due to contraction thereof since the peripheral end of the metal is fixed to the housings 24 and 25, to thereby eliminate or negate disadvantageous local tension caused by the welding. Of course, the same effect and function can be realized if the diaphragm is firstly fixed to the housings by brazing or pasting.
The second embodiment according to this invention will now be described with reference to FIG. 4 wherein like parts and components are designated by the same reference numerals and characters as those shown in FIG. 2. A differential pressure sensing device 22 includes first and second housings 24 and 25 which house insulations 4 and 5. An outer peripheral end of a sensing diaphragm 23 is welded to the housings 24 and 25. The sensing diaphragm in this instance may or may not be made of a precipitation hardenable material. The inner annular planes of the first and the second housings sandwich the peripheral end portion of the sensing diaphragm 23. Outer peripheral surfaces of the housings are tightly surrounded by a fixing plate 150 made of one of the above-described precipitation hardenable metals. After the fixing plate 150 is secured to the outer peripheral surfaces of the housings, the plate is subjected to a thermal, or aging, treatment.
As shown in FIGS. 4 and 5, the fixing plate 150 made of precipitation hardenable metal is welded to the outer peripheral surfaces of the housings 24 and 25, and thereafter the assembled device is subjected to heat treatment according to FIGS. 3(A) and 3(B). The fixing plate is preferably in the form of a pipe, or C-shape having a gap 150a, however alternatively, a plurality of subdivided plates may be provided around the housing along the axial direction thereof. For instance providing a plurality of gaps 150a would result in the division of the fixing member 150 into a plurality of plates, each of which extends in the axial direction in order to secure both housing members.
FIG. 6 shows the third embodiment of this invention which may be used to measure liquid level by utilizing a floating member 40 connected to a liquid lelel measuring device 220.
A sensing leaf spring disk 26 is centrally disposed in the device 220 and is supported to first and second housings 27 and 28 by welding. A fixing plate 29 is fixed to outer peripheral surfaces of the housings. The fixing plate is made of precipitation hardenable metal, and is subjected to aging treatment to ensure tight clamping between the housings. The disk spring 26 is provided with an electrical detecting element such as a strain gauge 30, 30 at opposite surfaces thereof to detect the deformation of the spring plate 26.
In order to avoid characteristic change of the strain gauge due to moisture, a pair of sealing diaphragms 33 and 34 are fixed to the respective outer planar surfaces of the housings, and non-compressive liquid such as silicone oil is filled in the spaces 35 and 36 defined between the sealing diaphragm 33 and the disk 26, and between the sealing diaphragm 34 and the disk 26, respectively. Supporting plates 37 and 38 are provided in the sealing diaphragm 33 and 34, respectively, and a supporting plate 32 provided in the disk 26 is connected to the supporting plates 37 and 38 by means of a connecting member 39 so that they operate integrally with each other. Since the plate 38 is connected to the floating member 40, the up and down movement of the float member caused by change of the buoyancy due to the change of the liquid level is transmitted to a support member 32 to thereby deform the spring disk plate 26.
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A compact sensing device is provided which the tension applied to the sensing member is substantially uniform and free of thermally changing. Either the sensing member itself or a clamping member disposed around the device or both, are made of a precipitation hardenable metal which will contract during a heat treatment. If the sensing member is thermally contracted a uniform radial tension will result, and if the clamping member is contracted a uniform clamping force applied to the device for tensioning the diaphragm will be provided without the necessity of clamping bolts.
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BACKGROUND OF THE INVENTION
The present invention relates generally to integrated circuit memory devices and, more particularly, to a synchronous dynamic random access memory (SDRAM) system.
Problems in state of the art memory systems have been because of intrinsic delays associated with memory read operations at high clock frequencies, and the increased write latency commensurate with increased read latencies, where non-zero latencies for read and write operations are the norm. In the case of ‘read’ operations, this data latency will be directly associated with the amount of time required to access the data from the sense amplifier latch or other intermediate storage location—typically 3 or 4 clocks at a 266 MHz clock speed. In the case of ‘write’ operations, whereas it is still theoretically possible to provide data and address at the same time, data will typically be delayed several clocks after address, to improve command/address bus efficiency and reduce SDRAM power—since read and write operations will generally be intermixed in the system command stream.
Due to the use of various forms of error correction code (ECC) now widely used on the data bus in server and workstations, most memory failures now result from causes other than traditional data corruption (soft and hard fails of the memory cell or supporting circuits). With the increased dependency on data storage in remote systems (databases, workrooms, department and company servers, and the internet in general), memory failures in server platforms are undergoing increased scrutiny in an attempt to minimize the time in which data or the entire system is unavailable due to hardware failures. Analysis of recent memory failure reports clearly points to the key contributors of memory-induced unplanned system outages as being related primarily to address, control, clock or related signals that do not include ECC coverage, and due to one or more of the following failure modes: connector/contact failures, memory controller or re-drive failures, high resistance solder joints, or the like. Since these signals are quite numerous, often passing through several levels of interconnects, and due to the general use of low-cost connectors, the interconnect systems are generally deemed as a significant contributor of memory failures in a well-architected ECC-protected system (representing 50% or more of total hard memory fails).
SUMMARY OF THE INVENTION
It is an object of the present invention to improve the overall memory system reliability without incurring additional latency.
Another object is to improve the detectability and correction of failures associated with interconnects.
One solution to improve the detectability and correction of failures associated with interconnects is to include error correction across all memory command and address signals, and correct any identified errors during valid operations to a given memory assembly. This approach can be very cost-effective, in that most high-reliability applications now utilize memory assemblies (modules) which include local command and address re-drive circuitry on the same carrier as the synchronous DRAM memory devices. To implement ECC across the command and address lines requires only that a few additional pins be added to the drivers, connectors and module re-drive circuits—in conjunction with the ECC logic. Unfortunately, this method also increases the memory access time, as the ECC logic will result in one to two clocks of added command and address latency (depending on the clock period and logic circuit delays). Since memory failures of this type are generally rare, and due to the system emphasis on minimizing access delays during cache misses, simple use of ECC, as described, is not an ideal solution in many applications.
The present invention couples the addition of a new SDRAM operation, ideally suited for emerging devices with non-zero write data latency, with command and address ECC implemented in parallel with the normal memory re-drive method (to ensure minimum memory read and write latency). In summary, the key attributes of this invention are as follows:
1) ECC logic is added to the memory control and address paths, with the intention that single or even multiple bit failures, during valid command cycles, can be corrected to prevent a system outage. It is expected that most will implement this ECC function external to the synchronous memory devices, although the memory devices could include this function as well.
2) Memory commands and addresses are passed to the memory devices, with minimal insertion delay, as the ECC logic function occurs in a parallel path. Should an error be identified by this logic, the ECC correction circuitry will enable rapid recovery without permitting data corruption in the memory.
3) In systems produced using memory devices with the new ‘cancel’ command:
Any ‘read’ or ‘write’ operations that are initiated using command and address inputs subsequently found to be valid, will be executed normally, and without added delay or interruption.
Any ‘read’ operations initiated using command and address inputs subsequently found to be invalid, will generally have the ‘read’ data discarded, and the device returned to an idle state awaiting error recovery. For completeness, the present invention includes the concept of early termination of a ‘read’ operation, since longer bursts are expected in future devices, and a performance savings is possible when recovering from an error.
Any ‘write’ operations initiated using command and address inputs subsequently found to be invalid, would be followed by a ‘Command Cancel (CC)’ command, to the same memory bank(s), to prevent the data stored by the memory device(s) from being over-written erroneously. The command would generally return the device to a ‘standby’ state, awaiting error recovery—although other return states are possible, and would be covered by this invention.
In an ideal system implementation, the memory would be designed to permit continuous operation in a traditional ECC mode (in series with the command and address) or in parallel mode—to ensure minimum latency.
4) System response to a memory command or address ECC error could include one or more of the following actions:
Re-try of failing operation while the ECC is operating in parallel mode, depending on the type of error identified. Some failures are intermittent in nature, and a repeat of the failure may be ideal to confirm the cause and/or determine the need for further action. This re-try would be completed with no change to ECC operating in parallel mode such as a “soft error.”
Execution of the cancelled operation with ECC being invoked in a serial mode which will add one or two clocks of latency. The memory controller or system re-drive logic would execute a new operation, correct single bit (or greater) errors depending on the ECC algorithm utilized and ensure valid operation.
The system would continue to operate with serial ECC enabled until a repair action occurred, or return to parallel ECC operation pending a repeated failure identification and recovery.
Various levels of reliability improvement can be implemented using this new command, depending on the amount of fault prevention desired when parallel command/address parity or ECC is invoked with the ‘command cancel’ function.
Some examples include:
To minimize the probability of issuing an illegal command that may result in significant recovery time, any critical signal(s) can include two separate contacts through each interconnect in the signal path—thereby adding contact redundancy to minimize failure due to discrete high resistance contact failures.
Low cost systems might invoke only parity checking on these signals, with the Command Cancel (CC) function utilized only to identify and terminate operations prior to data corruption. Normal operation would terminate to the affected memory and a recovery mode could be implemented such as, multiple re-tries.
To reduce recovery time and/or to simplify controller logic, the ‘command cancel’ operation can be included in both ‘read’ and ‘write’ operations. This is viable only if the DRAM implementation of this function includes both modes.
DESCRIPTION OF THE DRAWINGS
The above objects and advantages of the present invention will become more apparent by describing in detail preferred embodiments thereof with reference to the attached drawing in which:
FIG. 1 is a block diagram of the arrangement of present invention on a DIMM.
FIG. 2 is timing diagrams illustrating the waveforms for the DRAM for a read operation with two options for Command Cancel (CC) operation.
FIG. 3 is a block diagram of a read path in accordance with the present invention.
FIG. 4 is a block diagram of a write path in accordance with the present invention.
FIG. 5 is a timing diagram of normal write timings.
FIG. 6 is a timing diagram of the write timings in accordance with the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
A DRAM implementation of the ‘command cancel’ operation mentioned above can be implemented via a command decode, or via one or more unique pins (to maximize coverage of command bus failures). It should be understood that this is not the only technique that is appropriate—since memory interfaces are periodically re-defined, where T is less than or equal to one quarter of the cycle time of the 1/W clocks.
In summary, the operation of the present invention operates a novel Command Cancel (CC) system in both the read and write operations as follows:
Attention is directed to FIG. 1 which illustrates number of memory modules 10 known as dual in-line memory modules (DIMMS) on which number of Dynamic Random Access Memory 20 (DRAM) and a buffer chip 25 are mounted in a known manner.
The buffer chip receives address commands from an external memory controller or chip 30 and transmits the commands to the DRAMs 20 . The memory data is likewise transmitted and received from the memory controller 30 to the buffer chip 25 to and from the DRAMs 20 . It should be noted that the memory data may be wired directly from chip 30 to DRAMs 20 , rather than passing through buffer chip 25 .
The Command Cancel (CC) function would be implemented as shown in FIG. 1 on a DIMM buffer chip 25 via use of ECC logic connected to the Address and/or Command re-drive circuits not shown. The buffer chip could then have two Command Cancel output buffers; one coupled to the on-DIMM DRAM chips and another to drive back to the Memory Controller chip. Although this has been described, the Command Cancel function to the DRAMs as being implemented via one or more unique wires, it is well known in the art that other methods of communication, such as, a command decode could be placed on the existing buffer interface.
Implementation of the Command Cancel function on the DRAM chip takes advantage of the natural latch boundaries in a DDR synchronous DRAM. These latch boundaries, with the latencies of the Read or Write operation in the chip, provide for the interception and disabling of an undesired Read/Write command. In the case of the Write operation, it is critical that it is disabled before data in the DRAM array can be corrupted, by an unintended operation or some other problem
Read Operation
As shown in FIG. 2, in a Read operation, the Command Cancel could allow the DRAM to complete the Read data burst, but tri-state the memory bus I/O drivers on the DIMM Buffer Chip thereby allowing for other uses of this interface at this time. Another option would be for the DRAM to respond to the Command Cancel input by tri-stating the DRAM off-chip drivers and resetting the Internal DRAM circuits, saving both power and latency prior to recovery of normal operation.
The input/output waveforms shown in FIG. 2, on a DRAM chip, are for a Read operation that is to be cancelled. This example illustrates a chip operating with a Burst Length (BL)=4 and a CAS Latency (CL)=2. The DDR chip receives two clock inputs (CLK and bCLK) which may be a differential clock pair. Commands and Addresses are latched at the clock transition when CLK is rising. In this example, a Read Command and its associated Column Address are followed at the next rising edge of CLK by a Command Cancel operation.
Under Option 1, the DRAM does not respond to the Command Cancel signal CC. In this case, the Read data is bursted from the DRAM. The DIMM Buffer Chip however responds to the CC by keeping its buffers in tri-state so that the Read data is not driven off the DIMM onto the Memory Data bus. In this option, the data drivers on the DRAMs remain active until the data burst is completed (1), resulting in extra power consumption and possible loss of system performance due to the 2 cycle wait period related to the data bus, after the initial CC is issued.
Under option 2, the DRAM does respond to the CC, with the internal QENB signal remaining low and inhibiting DRAM driver activation.
As illustrated in FIG. 3, for the read path a clock generator 40 and a command block 41 transmits signals to a data enable circuit block (QENB) 45 and FIFO clocks 46 . The FIFO clocks 46 transmit control signals to the First In First Out (FIFO) logic 47 . The FIFO logic 47 shift registers catch data fetched from the array and hold it to be sent to the OCD. The proper sequencing of the data latched from the array and sent to the OCD is controlled by the FIFO Clocks. The QENB 45 transmits an enable signal to the off chip driver (OCD) 50 which is coupled to a Data Out pad (DQ) for normal Read operation of DRAM. If the OCD is desired to be in bidirectional Tri-State (the OCD in devices OFF), the QENB output would be held in the inverse binary state as that which would enable the OCD. The Command Cancel (CC) generator (CCGEN) 51 sends control signals to QENB 45 , FIFO clocks 46 and to the column path to reset the system if required. By contrast, during a Write Command, the QENB output state continuously keeps the OCD's in a Tri-state (high impedance condition).
Accordingly in Option 2, the DRAM internal logic in the Read path shown in FIG. 3 responds to the CC input by creating a On-DRAM CC signal from the CC generator. The CC signal will cancel the activation of the QENB signal. This keeps the DRAM off-chip drivers (OCD) in tri-state. The CC signal would also turn off and reset the FIFO clocks, thus ignoring any Read data that may become available on the internal DRAM data bus. This then provides for the data path to be reset and prepared for accepting the correct data after the subsequent corrected command or address is issued. The CC signal also propagates to the Column path where it will be used to reset the various latches and decoders which couple data read from the array to the Read path.
In this option, a new corrected command and address can be issued prior to when the data burst would have completed (2), saving power consumption and improving system recovery performance due to the 4 vs. 8 cycle wait period after the initial CC is issued.
In FIG. 4 is shown the Command Cancel generator, (CC Gen) 51 which will either by a discrete input pin or by an output of the on-chip Command Decoder, assert the CC signal. The CC signal will cancel the serial to parallel conversion of write input data in the Data In shift register circuits (Shift) 53 by disabling and resetting the double data rate (DDR) input shift register Clocks (CLKDS 0 , CLKDS 1 , CLKW). In read operation, this FIFO system requires one clock for each shift register which is required for an OCD. Accordingly, if there are four (4) FIFO registers required for the OCD, then there are four (4) FIFO clocks required to gate the proper FIFO data to the OCD. The reason for this is that data is fetched from the array in 2 bit or 4 bit chunks. The FIFO clocks need to decode the starting burst address so that the FIFO's data are sent to the OCD in the correct sequence. Without the FIFO clocks and their correlating the captured array data with the clock and the starting address, the data from the OCD would have no way to be in the proper correlation to the intended address. In a write cycle, this insures that the input data is not asserted to Data Lines (DIN 0 , DIN 1 ) and holds off the assertion of further commands generated by the normal cycling of the DDR shift register clocks. The CC signal will also propagate to reset the Secondary Sense Amp control circuits, the burst counter and the Address Path counters, latches and clocks.
The Command Cancel (CC) thus protects the corruption of the data in the DRAM array by an erroneous write command and/or address. To accomplish this in a standard double data rate DDR component with 2 bit pre-fetch would require that the Command Cancel (CC) be issued in time for the NEXT rising clock edge, so as to be latched by the DRAM chip and propagated to the DRAM Write Path.
This is due to the architecture of a double date rate (DDR) DRAM that allows high frequency operation of the chip while maintaining sufficient time to write data into the DRAM array storage cell. This is accomplished in the Write Path by a Serial to Parallel conversion of the incoming data. Thus in two clock cycles, the two serial input bits are converted to two parallel bits and sent to the array. The array now has two clock cycles to write the data while the next two bits in the Write data stream are undergoing their Serial to Parallel conversion.
FIG. 5 shows the voltage waveforms for the DDR write path schematic shown in FIG. 4, for normal operation. An external Write command (WRT) is asserted in phase with the external clock, rising edge (CLK). In this case, one clock later, the input data is asserted to the chip inputs. The shift register circuits, under the control of the DDR shift register clocks (CLKDS 0 , CLKDS 1 , CLKW) then transfer the serial data bits (WDin 0 , 1 ) onto the parallel internal data lines DIN 0 , DIN 1 , as shown by the propagation of the input data thru the internal nodes (WD 0 , sWD 0 , WD 1 ). As now can be realized the Write command is latched on the rising edge of CLK, which enables the Write Clock Generators, which provide the shift register clocks (CLKDS 0 , CLKDS 1 ) and the Write clock (CLKW), shown in FIG. 4 . The first Data In bit CWDin) is presented at the next rising clock edge after the assertion of the Write command and the second Data In bit is presented at the falling clock edge. These Data In bits ( 0 and 1 ) are latched and shifted by the Write clocks. In this manner the bits are converted from serial to parallel as shown in FIGS. 4 and 5 and sent to the array as DIN 0 and DIN 1 to be written to the selected DRAM array storage cells.
In FIG. 6 is shown the effect of the Command Cancel (CC) on the DDR data in the path. The Write command is again issued with the external clock. In this case, a Command Cancel (CC) is sent on the next full clock cycle later. The diagrams show that the CLKW is the important clock to be intercepted, so as shown, the CC disables and resets the DDR shift Clocks generator, and the input data is never transferred to the DIN 0 and DIN 1 lines. At the same time, the propagated CC would be resetting latches and clocks in the Secondary Sense Amp control circuits. Thus the CC operation in the Write path protects the array from corrupting data and also minimizes excessive extraneous currents for unneeded and unwanted data line and signal activation. This also contributes to reducing the latency for when the chip can accept a corrected input command.
Here the Command Cancel (CC) would be asserted at the next rising clock edge after the initial erroneous Write Command is received. The Command Cancel (CC) will be buffered by the Command Cancel (CC) receiver and sent to the Write Clocks Generator. The CC would then reset the CLKW generator such that the CLKW would not provide the pulse to transfer the shifted data input bits onto the Data In wires DIN 0 , DIN 1 with sufficient time to stop and reset. The waveforms are illustrated in FIG. 6 . The buffered on-chip CC command would also propagate to the Column path where it would reset the decode of the column to which the erroneous data bits were destined.
The Command Cancel (CC) concept is extendable to future DDR 2 and DDR 3 operating requirements in that the latency of these higher frequency modes will increase due to the scaling from 2 bit pre-fetch data path architectures to 4 and 8 bit pre-fetch. This results in 4 or 8 bit shifters in the Write path to provide the serial to parallel conversion that is shown in FIGS. 4, 5 , 6 for 2 bit pre-fetch. Therefore, future DDR proposals will still be able to incorporate a Command Cancel (CC) function similar to what is proposed above.
In a Read Operation the system could operate in either of two methods:
Method 1.) The Command Cancel (CC) function would be handled by the controller chip. In this scenario, the DRAM would not be interrupted. The DRAM would read out the data and the bits would be masked at the controller chip, thereby protecting the data stream to the processor. In this method, no extra circuits or signals are required for the Read path circuits.
Method 2.) The impact to system performance for a Command Cancel (CC) during a Read operation could be reduced, especially for longer Burst Length applications (BL=8) by an alternate method. In this case, the Command Cancel (CC) would be sent to the DRAM. This command would be latched, buffered on-chip and affect the following circuits;
Command Cancel (CC) would disable the Output Enable, tri-stating the DQ driver.
Command Cancel (CC) resets Burst Counter to 0.
Reset FIFO clocks.
Reset Column Command and Address Path latches, clocks.
Column Path will then function as if previous command has completed normally and take the “Ready” state which will leave the chip in an Active Standby (Array activated, awaiting a new Column Command). The DRAM control, address and clocking logic is ready for a new corrected Column Command/address.
Could save 4-6 clock edges of bus capacity to restart corrected command.
Write operation:
An erroneous Write operation to the DRAM is more problematic in that incorrect data or addresses presented to the DRAM can corrupt the data stored in the DRAM array. Therefore, for Writes, the Command Cancel (CC) must intercept and disable an erroneous Write operation. In the example above, where Write latency is greater than zero, the chip would receive a Write command and addresses, followed as many as 3 or 4 clocks later (DDR 11 and beyond) by the Write Data presented at the chip data inputs. If at this time the chip received a Command Cancel, or even <2 clocks (4 clock edges for DDR 2 ) after assertion of the Write data (assuming a 4 bit pre-fetch chip architecture), this Command Cancel (CC) would be latched, buffered on-chip and affect the following circuits:
Command Cancel would disable the Secondary Sense Amp control circuits (located in COLQSEG in an 512 Mb DRAM chip design).
This command has to be asserted, decoded and propagated to these circuits in time to insure that the MDQ's Write buffers are not activated. For a 4 bit pre-fetch architecture, it takes 4 clock edges to shift in the data for series to parallel input data conversion. The Command Cancel has to be asserted such that the COLQSEG logic can be deactivated before the 4th clock edge after the applied data.
Command Cancel signal (CC) resets Burst Counter to 0.
Reset DDR input shift registers clocks see FIGS. 4, 5 and 6 .
Reset Column Command and Address Path latches, clocks.
Column Path will then function as if previous command has completed normally and take the “Ready” state.
Leave chip in Active Standby (Array activated, awaiting a new Column Command) The DRAM control, address and clocking logic is ready for a new corrected Column Command/address.
Could save bus capacity to restart corrected command.
It should now be understood that due to today's high performance (DDR 2 ) DRAM architectures and circuit technologies, a Command Cancel (CC) function, if applied at least (n−1) clock edges after receipt of a Command (where n=the latency, in clocks, of the read or write operation), could disable the previous command/address/data and reset the internal DRAM circuits—leaving the DRAM in an active ready state to accept a corrected input vector. In a similar fashion to that described above, this function could be extended to Row Command cancellation. In this case, the command would be intercepted and disabled prior to array activation. Thus the array would remain in Standby and ready to accept the corrected input vector.
As described above, the invention offers improved memory subsystem performance by negating the added latency penalty that would normally be incurred through the use of ECC in the memory command and/or address path. Since command/address signal failures are very rare, and since both read and write operations now include non-zero data latency, the addition of this new command to the memory device will permit ECC to be operated in parallel or in series with the normal access path.
Parity and/or ECC has never utilized implementations that included the ability to terminate a read or write operation, to a memory device, subsequent to that command being issued. This new method will permit systems to implement parity or ECC across the command/address bus, operate this feature in parallel to the critical access path, and to subsequently terminate any command later found to be corrupt—prior to data being read or written. This invention could not be implemented without the combination of non-zero device read/write latency, the new ‘command cancel’ command, and the use of parallel fault detection/correction—hence this disclosure covers both the memory device and the memory subsystem.
Although 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 department from the spirit and scope invention.
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A synchronous dynamic random access memory (SDRAM) semiconductor device which uses a command cancel function to improve reliability and speed of a memory system. The CC function takes advantage of the intrinsic delays associated with memory read operations at high clock frequencies, and the increased write latency commensurate with increased read latencies where non-zero latencies for read and write operations are the norm by permitting address and command ECC structures to operate in parallel with the address and command re-drive circuits. The CC function is extendable to future DDR2 and DDR3 operating requirements in which latency of higher frequency modes will increase due to a shift from 2 bit pre-fetch to 4 and 8 bit pre-fetch architecture.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to thermally-responsive record material. It more particularly relates to such record material in the form of sheets coated with color-forming systems comprising chromogenic material (electron-donating dye precursors) and acidic (electron accepting) color developer material. The invention particularly concerns thermally imaging record materials imaged with sensitive information such as prescriptions, prescription container labels, government forms, tax returns, banking statements, credit card receipts, account information and the like, where privacy or security of the information is desirable.
2. Description of the Related Art
Thermally-responsive record material systems are well known in the art and are described in many patents, for example, U.S. Pat. Nos. 3,539,375; 3,674,535; 3,746,675; 4,151,748; 4,181,771; 4,246,318; 4,470,057 which are incorporated herein by reference. In these systems, basic chromogenic material and acidic color developer material are contained in a coating on a substrate which, when heated to a suitable temperature, melt or soften to permit said materials to react, thereby producing a colored mark.
Thermally-responsive record materials are typically imaged by use of a thermal print head that is moved across the sheet (serial type) or against which the sheet is moved. The thermal printhead can span the width of the sheet (line type). The thermal printhead typically has resistive heating elements. A microprocessor is used to selectively heat the individual heating elements to produce the desired image. Typically the finer the heat elements, the less power is required to produce dots that make up the image. The finer the dots and concentration of dots per unit area, the higher is the resolution.
Thermally-responsive record material systems due to their ease of use, low cost, high resolution, and simple operation have gained acceptance supplanting dot matrix printing in many applications.
With increasing concerns relating to information security, prevention of identity theft, and protection of personal privacy, a variety of techniques have been adopted to preserve the confidentiality of printed information. These techniques include shredding, burning, and other means of information destruction. With passage of ever more stringent privacy obligations such as patients rights bills, and other legislation, such as HIPPA requirements in the U.S., there is an increasing need to control private information to maintain confidentiality, reduce liability exposure, reduce risk of administrative agency imposed fines for non-compliance and prevent careless or inadvertent disclosure of private information.
A need exists in some circumstances for rapid destruction of private or sensitive information in bulk. Techniques such as shredding have the drawback of noise, susceptibility to jamming, or possibility of reassembly of information by a determined party. Techniques relying on burning, convection heating, or heating elements are undesirable in many office environments due to safety concerns associated with hot surfaces, fumes, and cleanliness issues in having to deal with ash.
It is an object of the present invention to teach a novel thermal recording system suitable for office environments which when imaged with personal information can be rapidly obscured in bulk without burning or use of devices characterized by fumes or hot surfaces.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view cross section of a thermally responsive record material according to the invention that depicts a layer of material susceptible to inductive heating (energy receiver material) as a coating or laminate to the underside of a sheet of paper.
FIG. 2 is an alternate embodiment where the energy receiver material is a subcoat under the heat sensitive layer but on the top surface of the sheet of paper.
FIG. 3 is a top view of an alternative embodiment shown as a substrate constituting a pharmaceutical prescription label for typically applying to a pharmaceutical container containing an energy receiver material (not shown) covering only a portion of the sheet depicted as patient information field 5 obscured after inductive heating yielding obscured patient information field 5 a.
SUMMARY OF THE INVENTION
Disclosed is a thermally-responsive record material comprising a substrate having provided thereon a heat sensitive color-forming composition comprising a chromogenic material and an electron accepting developer material. Overcoated over or under the heat sensitive color-forming composition or on the underside of the substrate is at least one layer of a material susceptible to inductive heat including RF or microwave heating (energy receiver material). Inductive heating is used in an expansive sense not limited merely to electromagnetic induction but intended to refer to flameless means of energy transfer to create heat in the energy receiver material. RF or microwave heating are to be understood as encompassed by the term inductive heating as used herein.
In yet another embodiment the invention is a system for obscuring confidential information imaged on a thermal record material and comprises a substrate having first surface and second surfaces and having provided on the first surface one or more layers of a heat sensitive composition comprising a chromogenic material and an electron accepting developer material, and, at least one layer of an energy receiver material in proximity to the heat sensitive composition. The heat sensitive composition on the first surface is applied to all or a portion of the first surface and the energy receiver material is applied to all or only a portion of the first surface or second surface or applied as an overcoat over all or a portion of the heat sensitive composition.
A microwave emitter such as a microwave oven can be employed for colorizing the heat sensitive composition layer or layers in proximity to the energy receiver material by heating the energy receiver material by microwave absorption so as to obscure information imaged in the heat sensitive composition.
In yet another embodiment, a method for obscuring confidential information is disclosed and comprises the steps of providing a substrate having first and second surfaces; providing on the first surface one or more layers of a heat sensitive composition comprising a chromogenic material and an electron accepting developer material; providing on all or a portion of the second surface a layer of an energy receiver material, recording information on to the first surface; and colorizing the heat sensitive composition layer or layers in proximity to the energy receiver material by heating the energy receiver material by microwave absorption so as to obscure the information recorded on the surface. Information can be recorded onto the first surface by conventional printing or by selectively thermally imaging the heat sensitive composition so as to record the information therein.
In yet another embodiment, the invention is a method for obscuring confidential information comprising providing a substrate having first and second surfaces; providing on the first surface one or more layers of a heat sensitive composition comprising a chromogenic material and an electron accepting developer material; providing on all or a portion of the second surface a layer of an energy receiver material in proximity to the heat sensitive composition; applying the substrate as a label onto a pharmaceutical container; recording information onto the first surface; and colorizing the heat sensitive composition layer or layers in proximity to the energy receiver material by microwave absorption so as to obscure information recorded on the first surface. Information can be recorded onto the first surface by conventional printing or by selectively thermally imaging the heat sensitive composition so as to record the information therein.
In one embodiment of the thermally-responsive record material, the material susceptible to inductive heating can be coated only over or under a portion of the heat sensitive color-forming composition provided on the substrate or applied as a back coating to a portion of the substrate. Alternatively, the heat sensitive color-forming composition is coated only over a portion of the substrate surface. In yet another embodiment the energy receiver material and the heat sensitive color-forming composition are both coated only over a portion of the substrate surface. Variations of such full or partial covering of the substrate with one or both coatings will be readily evident to the skilled artisan, as well as the use of optional intervening layers such as protectant layers, binders, antioxidant layers, UV absorbing layers and the like.
DETAILED DESCRIPTION
The present invention teaches thermally responsive record material comprising a substrate having provided thereon a heat sensitive color forming composition comprising: a chromogenic material and an electron accepting developer material, and, at least one layer of a material susceptible to inductive heating.
By “induction” or “inductive heating”, it is meant that the energy receiver material absorbs energy such as microwave, infrared, radio frequency, or magnetic, and the term is intended liberally to encompass electromagnetic induction, RF (radio frequency), microwave, infrared and dielectric heating. Inductive heating for purposes hereof differs from conventional heating primarily in that no open flame is used, fumes are minimized and the inductive heating devices generally can be designed with cool-to-the-touch exteriors as is commonly observed for example with microwave ovens.
The material susceptible to inductive heating is an energy receiver material and preferably comprises a microwave susceptor meaning a microwave absorber, RF absorber, or dielectric material. A microwave susceptor is more preferred. The energy receiver material or microwave susceptor can take the form of a metallized film, metal coatings, various particles including metal particles, silicon carbide, carbon fibers, metal oxides, ferrite particles, metal fibers, metallic flakes, nonconductive composites of energy dissipative materials or particles dispersed in a dielectric binder, by way of illustration and not limitation. Materials such as bronze powders, graphite, and aluminum flake, were used in the examples herein producing substrates that heated rapidly and obscured sensitive information when placed in a conventional microwave oven for about 30 seconds.
By “particle,” “particles,” “particulate,” “particulates,” “powder,” “fibers,” “flakes” and the like, it is meant that a material is generally in the form of discrete units. The particles can include granules, pulverulents, powders, spheres or flakes. Thus, the particles can have any desired shape such as, for example, cubic, rod-like, polyhedral, spherical or semi-spherical, rounded or semi-rounded, angular, irregular, flat or plate-like, etc. Shapes having a large greatest dimension/smallest dimension ratio, like needles, flakes and fibers, are also contemplated for use herein. The use of “particle” or “particulate” may also describe an agglomeration including more than one particle, particulate, or the like.
The term “surface” and its plural generally refer herein to the outer or the topmost boundary of an object, unless the context indicates otherwise.
As used herein, the terms “in proximity to” or “in intimate association” and other similar terms are intended to encompass configurations including the following: those where at least a portion of the material susceptible to inductive heating or energy receiver material is in contact with or proximate to or under or over a portion of the heat sensitive layer; and/or those where at least a portion of an energy receiver material is in contact with a portion of another energy receiver material such as in, for example, a layered or mixed configuration, over or under the heat sensitive layer (including over or under intervening intermediate layers) or as an underside coating of the substrate, such as paper substrate.
A suitable energy receiver material absorbs energy at the desired frequency (typically between about 0.01 to about 300 GHz) very rapidly, in the range of fractions of a second or a few seconds. In practice, the substrate coated with the energy receiver material was found to heat the overall substrate to a temperature approaching 150° C. to 235° C. sufficient to darken the heat sensitive composition after about 30 seconds in a microwave oven. Shorter or longer times would be expected depending on the loading in the microwave oven, amount of absorber and the like.
A suitable energy receiver material should have a dielectric constant that is relatively high. The dielectric constant is a measure of how receptive to high frequency energy such as microwave energy a material is. These values apparently can be measured directly using instruments such as a Network Analyzer with a low power external electric field (i.e., 0 dBm to about +5 dBm) typically over a frequency range of about 300 kHz to about 3 GHz, although Network Analyzers to 20 GHz are readily available. For example, a suitable measuring system can include an HP8720D Dielectric Probe and a model HP8714C Network Analyzer, both available from Agilent Technologies (Brookfield, Wis., U.S.A.). Substantially equivalent devices may also be employed. Energy receiver materials useful in the present invention typically have a dielectric constant—measured in the frequency range of about 900 to about 3,000 MHz—of at least about 4; alternatively, at least 4; alternatively, at least about 8; alternatively, at least 8; alternatively, at least about 15; or alternatively, at least 15.
Examples of materials that may be suitable energy receiver materials or materials susceptible to inductive heating for purposes hereof, have been reported as having the noted dielectric constants: titanium dioxide (110), titanium oxide (40-50), sugar, sorbitol, ferrous sulfate (14.2), ferrous oxide (14.2), calcium superphosphate (14-15), zircon (12), graphite, high density carbon black (1215), calcium oxide granules (11.8), barium sulfate (11.4), ruby (11.3), silver chloride (11.2), silicon (11-12), magnesium oxide (9.7), alumina (9.3-11.5), anhydrous sodium carbonate (8.4), calcite (8), mica (7), dolomite (6.8-8). Other examples include, but are not limited to, various mixed valent oxides such as magnetite (Fe 3 O 4 ), nickel oxide (NiO) and such; ferrite, tin oxide, zinc oxide, carbon, carbon black and graphite; sulfide semiconductors such as FeS 2 , CuFeS 2 ; silicon carbide; various metal powders, particulates or fibers, such as aluminum, copper, bronze, iron and the like; various hydrated salts and other salts, such as calcium chloride dihydrate; polybutylene succinate and poly(butylene succinate-co-adipate), polymers and co-polymers of polylactic acid, various hygroscopic or water absorbing materials or more generally polymers or copolymers or non-polymers with many sites with —OH groups; other inorganic microwave absorbers including metals, aluminum hydroxide, zinc oxide, varium titanate and other organic absorbers such as polymers containing ester, aldehyde, ketone, isocyanate, phenol, nitrile, carboxyl, vinylidene chloride, ethylene oxide, methylene oxide, epoxy, amine groups, polypyrroles, polyanilines, polyalkylthiophenes, and mixtures thereof.
It should be further noted that the present invention is not limited to the use of only one material susceptible to inductive heating, but could also include mixtures of two or more such energy receiver materials. As previously indicated, the energy receiver material may be in particulate form; consequently, it is understood that the particles of energy receiver material may include solid particles, porous particles, or may be an agglomeration of more than one particle of energy receiver material. One skilled in the art would readily appreciate the possibility of treating the surface of a particle of energy receptive additive to enhance its ability to efficiently absorb microwave energy. Suitable surface treatments include scoring, etching, and the like. The energy receipt additive may also be in the form of an absorbed liquid or semi-liquid. In particular, a solution, dispersion or emulsion of one or more effective energy receptive additives may be formulated. When so deposited, at least a portion of the energy receptive additive would come into intimate association with or proximity to the heat sensitive composition.
In various embodiments of the present invention, the intimate association of an energy receiver material may be achieved with the optional use of a binder material. The binder material can include substances that can be applied in liquid or semi-liquid form to the energy receptive additive. The term “applied” as used herein is intended to include situations where: at least a portion of the surface of a particle of material susceptible to inductive heating has an effective amount of binder material on it or containing it to facilitate adherence, via mechanical and/or chemical bonding of at least a portion of the surface of the record material or heat sensitive layer to at least a portion of the material susceptible to inductive heating. In yet a further embodiment, the energy receiver material may be blended into the pulp mill furnish to disperse the energy receiver as an integral part of the manufactured paper substrate. In another embodiment the energy receiver material may be dispersed in any polymer and hot extruded into a film, co-extruded as a separate layer in a multi-layer co-extrusion or coated to the surface of a substrate as part of a multi-layer laminate. In yet another embodiment the energy receiver material can be sputter coated, spray coated, or electrodeposited onto the substrate or as a back coat to the substrate. Any commonly used technique to metalize or apply foils can also be advantageously used.
The energy receiver material can be dispersed in a binder material or dispersant such as a polymeric acrylate or polyvinyl alcohol to form a coating. The coating can be applied onto a surface of the substrate forming a subcoat or backcoat as desired. An optional surfactant can aid dispersion helping to form a coating slurry.
The selection of a particular binder material can be made by one skilled in the art and will typically depend upon the chemical composition of the materials to be maintained in intimate association with one another. The binder material is typically prepared by the formation of a liquid or semi-liquid or slurry. In particular, a solution, dispersion or emulsion including at least one of the various, preferably polymeric binder materials identified herein may be prepared. It may be applied to the selected material by any method such as by spraying in liquid or semi-liquid form, rod coating, curtain coating, blade coating, air knife coating and the like.
Alternatively, the energy receiver material particles can be dispersed into the substrate, such as into the furnish when a paper substrate is being formed such as using a Fourdinier paper machine. Similar dispersion into a film substrate during extrusion, for example, can be accomplished.
Looking now at the drawings FIG. 1 illustrates a general type of construction. FIG. 1 is a side view cross section of a thermally responsive record material according to the invention. Basestock paper 2 is shown having heat sensitive layer 1 coated onto the top surface. Energy receiver material layer 3 is coated or laminated onto the underside of basestock paper 2 .
FIG. 2 illustrates an alternative embodiment where basestock paper 2 is coated or laminated on the top surface with energy receiver material layer 3 . A heat sensitive layer 1 is overcoated over energy receiver material layer 3 .
A pressure sensitive adhesive layer 4 is shown in FIGS. 1 and 2 as a bottom layer of the laminate or coated construction.
The general type of construction of the laminate layers or coating layers depicted in FIGS. 1 and 2 of a record material according to the invention can take the form a variety of architectures, as further illustrated in the ordering of the respective layers of a laminate described in Variations 1 to 4 below.
Variation 1
Heat sensitive (imaging) layer
Basestock paper
Adhesive
Metallized film
Pressure sensitive adhesive layer
Variation 2
Heat sensitive (imaging) layer
Subcoat
Metallized basestock
Pressure sensitive adhesive layer
Variation 3
Heat sensitive (imaging) layer
Subcoat with metallic particles
Basestock paper
Pressure sensitive adhesive layer
Variation 4
Top coat
Heat sensitive (imaging) layer
Subcoat
Basestock paper
Metallized undercoat
Pressure sensitive adhesive layer
In Variation 1 the heat sensitive layer is to the top surface of a sheet or web of basestock paper. A metallized film for example can be adhesively laminated or melt extruded to an underside of the basestock paper. The metallized film would function as the energy receiver material in this variation. A pressure sensitive adhesive is coated onto the underside of the metallized film.
In Variation 2 the heat sensitive layer is applied over a subcoat such as a clay or energy reflecting layer such as insulated foam or microbeads or hollow sphere materials. Under the subcoat layer is a metallized basestock serving as the energy receiver material. This can take the form of metallic powders or particles distributed through the basestock paper as part of the paper furnish during paper manufacture or as a coating over or under the paper applied subsequent to basestock paper manufacture.
In Variation 3 a heat sensitive layer is coated onto a subcoat that contains energy receiver material such as metallic particles. The subcoat is coated or adhered onto the top surface of the basestock paper. A pressure sensitive adhesive is indicated as the bottom surface of this construction.
In Variation 4 a protective top coat such as a UV layer or polymeric material such as polyvinyl alcohol or polyacrylate is provided as the top layer over the heat sensitive layer. The heat sensitive layer is coated over a subcoat such as clay or heat insulating material to facilitate imaging of the heat sensitive layer. To the bottom surface of the basestock paper there is coated, adhered or melt extruded an energy receptive material such as a metallized undercoat or metallic particulate dispersed in a binder material.
The heat sensitive layer or thermally responsive record material comprises a support having provided thereon in substantially contiguous relationship an electron donating dye precursor (chromogenic material), an acidic developer material, and optionally a sensitizer and binder therefor.
The record material according to the invention has a non-reversible image in that it is substantially non-reversible under the action of heat. The coating of the record material of the invention is basically a dewatered solid at ambient temperature.
The color-forming system of the record material of this invention includes chromogenic material (electron-donating dye precursor) in its substantially colorless or light-colored state and acidic developer material. The color-forming system relies upon melting, softening, or subliming one or more of the components to achieve reactive, color-producing contact with the chromogen.
The record material includes a substrate or support material which is generally in sheet form. For purposes of this invention, sheets can be referred to as support members and are understood to also mean webs, ribbons, tapes, belts, films, cards and the like. Sheets denote articles having two large surface dimensions and a comparatively small thickness dimension. The substrate or support material can be opaque, transparent or translucent and could, itself, be colored or not. The material can be fibrous including, for example, paper or plastic such as filamentous synthetic materials. It can be a plastic such as film including, for example, cellophane and synthetic polymeric sheets cast, extruded, or otherwise formed. The invention primarily resides in the compositions coated on or under the substrate. In certain embodiments, the energy receiver material is applied as a back coat to all or a portion of the underside of the substrate. In alternative embodiments the energy receiver material is dispersed within the substrate such as within the paper furnish during paper manufacture. The type of substrate is a matter of selection and preference without limitation.
The components of the color-forming system are in substantially contiguous relationship, substantially homogeneously distributed throughout the coated layer material deposited on the substrate. The term substantially contiguous is understood to mean that the color-forming components are positioned in sufficient proximity such that upon melting, softening or subliming one or more of the components, a reactive color forming contact between the components is achieved. As is readily apparent to the person of ordinary skill in this art, these reactive components accordingly can be in the same coated layer or layers, or isolated or positioned in separate but adjacent layers. In other words, one component can be positioned in the first layer, and reactive or sensitizer components positioned in a subsequent layer or layers. All such arrangements are understood herein as being substantially contiguous.
In manufacturing the record material, a coating composition is prepared which includes a fine dispersion of the components of the color-forming system, binder material preferably polymeric binder such as polyvinyl alcohol or acrylic latex, surface active agents and other additives in an aqueous coating medium. Surfactants for the color forming system or dispersing the energy receiver material can include any of various surface active materials, and without limitation include sodium dodecylsulfate, sodium dodecylbenzene sulfate, cetyl trimethyl ammonium bromide, acetylenic glycol and the like. The composition can additionally contain inert pigments, such as clay, talc, silicone dioxide, aluminum hydroxide, calcined kaolin clay and calcium carbonate; synthetic pigments, such as urea-formaldehyde resin pigments; natural waxes such as Carnauba wax; synthetic waxes; lubricants such as zinc stearate; wetting agents; defoamers, sensitizers and antioxidants and p-benzylbiphenyl. Modifiers or sensitizers can also be included in the heat sensitive layer or composition. Sensitizers for example can include acetoacet-o-toluidine, phenyl-1-hydroxy-2-nophthoate, 1,2-diphenonxyethane, p-benzylbiphenyl, benzyl acetate, benzyloxyphenyl ethers (U.S. Pat. Nos. 6,566,301; 6,599,097; and 6,429,341). The sensitizer typically does not impact any image on its own but as a relatively low melt point solid acts as a solvent to facilitate reaction between the mark forming components of the color-forming system.
The color-forming system components are substantially insoluble in the dispersion vehicle (preferably water) and are ground to an individual average particle size of between about 1 micron to about 10 microns, preferably about 1-3 microns or less. The polymeric binder material is substantially vehicle soluble or a latex dispersion. Preferred water soluble binders include polyvinyl alcohol, hydroxy ethylcellulose, methylcellulose, methyl-hydroxypropylcellulose, starch, modified starches, gelatin and the like. Eligible latex materials include polyacrylates, styrene-butadiene-rubber latexes, polyvinylacetates, polystyrene, and the like. The polymeric binder is used to protect the coated materials from brushing and handling forces occasioned by storage and use of thermal sheets. Binder should be present in an amount to afford such protection in an amount less than will interfere with achieving reactive contact between color-forming reactive materials.
Coating weights can effectively be about 2 to about 9 grams per square meter (gsm) and preferably about 5 to about 6 gsm. Coat weight of the energy receiver material can be considerably less, as little as 0.05 grams per square meter in some applications. The practical amount of color-forming materials or energy receiver materials is controlled by economic considerations, functional parameters and desired handling characteristics of the coated sheets.
Eligible electron donating dye precursors are chromogenic materials, such as the phthalide, leucauramine and fluoran compounds, for use in the color-forming system. Various chromogenic materials for use in color-forming systems are well known color-forming compounds or dye precursors. Examples of the compounds include Crystal Violet Lactone (3,3-bis(4-dimethylaminophenyl)-6-dimethylaminophthalide, U.S. Pat. No. RE. 23,024); phenyl-incol-, pyrrol-, and carbazol-substituted phthalides (for example in U.S. Pat. Nos. 3,491,111; 3,491,112; 3,491,116; 3,509,174); nitro-, amino-, amido-, sulfon amido-, aminobenzylidene-, halo-, anilino-substituted fluorans (for example, in U.S. Pat. Nos. 3,624,107; 3,627,787, 3,641,011; 3,642,828; 3,681,390); spiro-dipyrans (U.S. Pat. No. 3,971,808); and pyridine and pyrazine compounds (for example, in U.S. Pat. Nos. 3,775,424 and 3,853,869). Other specifically eligible chromogenic compounds, not limiting the invention to any way, are: 3-diethylamino-6-methyl-7-anilino-fluoran (U.S. Pat. No. 3,681,390); 2-anilino-3-methyl-6-dibutylamino-fluoran (U.S. Pat. No. 4,510,513) also known as 3-dibutylamino-6-methyl-7-anilino-fluoran; 3-dibutylamino-7-(2-chloroanilino)fluoran; 3-(N-ethyl-N-tetrahydrofurfurylamino)-6-methyl-7-3,5,6-tris(dime-thylamino)spiro 9H-fluorene-9,1′, (3′H)-isobenzofuran!-3′-one; 7-(1-ethyl-2-methylindol-3-yl)-7-(4-diethylamino-2-ethoxyphenyl)-5,7-dihydrofuro 3,4-b!pyridin-5-one (U.S. Pat. No. 4,246,318); 3-diethylamino-7-(2-chloroanilino)fluoran (U.S. Pat. No. 3,920,510); 3-(N-methylcyclohexylamino)-6-methyl-7-anilinofluoran (U.S. Pat. No. 3,959,571); 7-(1-octyl-2-methylindol-3-yl)-7-(4-diethylamino-2-ethoxyphenyl)-5,7-dihydrofuro 3,4-b!pyridin-5-one; 3-diethylamino-7,8-benzofluoran; 3,3-bis(1-ethyl-2-methylindo 1-3-yl)phthalide; 3-diethylamino-7-anilinofluoran; 3-diethylamino-7-benzylaminofluoran; 3,-phenyl-7-dibenzylamino-2,2′-spiro-di- 2H-1-benzopyran! and mixtures of any of the following.
Examples of eligible acidic developer material include the compounds listed in U.S. Pat. No. 3,539,375 as phenolic reactive material, particularly the monophenols and diphenols. Other eligible acidic developer material which can be used also include, without being considered as limiting, the following compounds:
4,4′-isopropylidinediphenol(Bisphenol A); p-hydroxybenzaldehyde; p-hydroxybenzophenone; p-hydroxypropiophenone; 2,4-dihydroxybenzophenone; 1,1-bis(4-hydroxyphenyl)cyclohexane; salicyanilide; 4-hydroxy-2-methylacetophenone; 2-acetylbenzoic acid; m-hydroxyacetanilide; p-hydroxyacetanilide; 2,4-dihydroxyacetophenone; 4-hydroxy-4,-methylbenzophenone; 4,4′-dihydroxybenzophenone; 2,2-bis(4-hydroxyphenyl)-4-methylpentane; benzyl 4-hydroxyphenyl ketone; 2,2-bis(4-hydroxyphenyl)-5-methylhexane; ethyl-4,4-bis(4-hydroxyphenyl)-pentanoate; isopropyl-4,4-bis(4-hydroxyphenyl)pentanoate; methyl-4,4-bis(4-hydroxyphenyl)pentanoate; alkyl-4,4-bis(4-hydroxyphenyl)pentanoate; 3,3-bis(4-hydroxyphenyl-pentane; 4,4-bis(4-hydroxyphenyl pentanoate; 3,3-bis(4-hydroxyphenyl)-pentane; 4,4-bis(4-hydroxyphenyl)-heptane; 2,2-bis(4-hydroxy-phenyl) butane; 2,2,-methylene-bis(4-ethyl-6-tertiarybutyl phenol); 4-hydroxy-coumarin; 7-hydroxy-4-methylcoumarin; 2,2,-methylene-bis(4-octylphenol); 4,4,-sulfonyldiphenol; 4,4′-thiobis(6-tertiarybutyl-m-cresol); methyl-p-hydroxybenzoate; n-propyl-p-hydroxybenzoate; benzyl-p-hydroxybenzoate. Preferred among these are the phenolic developer compounds. More preferred among the phenol compounds are 4,4,-isopropylindinediphenol, ethyl-4,4-bis(4-hydroxyphenyl)-pentanoate, n-propyl-4,4-bis(4-hydroxyphenyl)pentanoate, isopropyl-4,4-bis(4-hydroxyphenyl)pentanoate, -methyl-4,4-bis(4-hydroxyphenyl)pentanoate, 2,2-bis(4-hydroxy-phenyl)-4-4-methylpentane, p-hydroxybenzophenone, 2,4-dihydroxybenzophenone, 1,1-bis(4-hydroxyphenyl)cyclohexane, and benzyl-p-hydroxybenzoate. Acid compounds of other kind and types are eligible.
Examples of other eligible acidic developer compounds for use with the invention are phenolic novolak resins which are the product of reaction between, for example, formaldehyde and a phenol such as an alkylphenol, e.g., p-octylphenol, or other phenols such as p-phenylphenol, and the like; and acid mineral materials including colloidal silica, kaolin, bentonite, attapulgite, hallosyte, and the like. Some of the polymers and minerals do not melt but undergo color reaction on fusion of the chromogen.
Coating can be applied by any conventional means such as air knife, blade, rod, flexo, slot die, slot fed curtain, multi-layer slot die, multi-layer slot die fed curtain, slide die, slide die fed curtain, multi-layer slide die fed curtain and the like.
The following examples are given to illustrate some of the features of the present invention and should not be considered as limiting. Unless otherwise indicated, all measurements, parts and proportions herein are in the metric system and on the basis of weight.
All patents and publications cited herein are hereby fully incorporated by reference in their entirety. The citation of any publication is for its disclosure prior to the filing date and should not be construed as an admission that such publication is prior art or that the present invention is not entitled to antedate such publication by virtue of prior invention.
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, are not to be construed as limited to the particular forms disclosed, since those are to be regarded as illustrative rather than restrictive. Variations and changes can be made by those skilled in the art without departing from the spirit and scope of the invention.
EXAMPLES
Samples were prepared and imaged in a conventional microwave oven (Sharp R-230H, 1200 watt). The Sharp microwave has a “minute plus” quick heat option. Desirably, the heating and darkening of the label occurs in minutes and more preferably in seconds. With the following examples, darkening was generally observed and the image obscured at about 30 seconds.
The microwave susceptor material should be capable of being heated up to a temperature of about 232° C. and more preferably in a temperature range of about 150° C. to 225° C.
Formula 1
13 parts acrylic binder a polymer at 50% solids
0.2 parts surfactant (Acetylenic glycol, Surfynol™ 440, Air Products, Allentown, Pa.)
4.5 parts bronze powder, 98% sized less than 74 microns
0-10 parts water to achieve coat weight
Formula 2
18 parts acrylic binder polymer at 50% solids
0.2 parts surfactant (acetylenic glycol)
3 parts bronze powder, 98% sized less than 74 microns
2 parts aluminum flake, particle size 8-18 microns
0-10 parts water to achieve coat weight
Formula 3
5 parts acrylic binder polymer at 31.5% solids
0.2 parts surfactant (acetylenic glycol)
3 parts graphite powder, particle size 1-2 micron
7-15 parts water to achieve coat weight
Formula 4
10 parts acrylic binder polymer at 31.5% solids
0.2 parts surfactant (acetylenic glycol)
3 parts graphite powder, particle size 1.2 micron
7-15 parts water added to achieve coat weight
Formula 5
10 parts acrylic binder polymer at 31.5% solids
0.2 parts surfactant (acetylenic glycol)
3 parts graphite powder, particle size 1.2 micron
3 parts magnesium iodate tetrahydrate
7-15 parts water added to achieve coat weight
Formula 6—Thermal Basecoat
45 parts styrene butadiene rubber latex at 50% solids
1 parts surfactant (acetylenic glycol)
70 parts calcined clay
70-100 parts water to achieve coat weight and wet out clay
Formula 7—Thermal Active Coat
10 parts styrene butadiene rubber latex at 50% solids
60 parts 4-hydroxyphenyl-4′-isopropoxyphenyl sulfone at 50% solids
5 parts polyvinyl alcohol at 20% solids
70 parts dimethyl terephthalate at 50% solids
45 parts 3-di-n-butylamino)-6-methyl-7-anilino fluoran, at 38% solids
6-10 parts water to achieve coat weight
Formula 8—Thermal Topcoat
100 parts carboxylated polyvinyl alcohol at 15% solids
0.4 parts surfactant (acetylenic glycol)
50 parts pigment dispersion at 50% solids
5 parts zinc stearate dispersion at 44% solids
35 parts cross-linking agent at 12.5% solids
5-10 parts water to achieve coat weight
Example 1
Layer 1—Formula 8—thermal topcoat @ 2.0 lbs/ream (0.9 kg/ream)
Layer 2—Formula 7—thermal activecoat @ 2.5 lbs/ream (1.1 kg/ream)
Layer 3—Formula 6—thermal basecoat @ 5.0 lbs/ream (2.2 kg/ream)
Layer 4—paper substrate
Layer 5—Formula 1—microwave susceptor @ 6 lbs/ream (2.7 kg/ream)
Example 2
Layer 1—Formula 8—thermal topcoat @ 2.0 lbs/ream (0.9 kg/ream)
Layer 2—Formula 7—thermal activecoat @ 2.5 lbs/ream (1.10 kg/ream)
Layer 3—Formula 6—thermal basecoat @ 5.0 lbs/ream (2.2 kg/ream)
Layer 4—paper substrate
Layer 5—Formula 2—microwave susceptor @ 6 lbs/ream (4.08 kg/ream)
Example 3
Layer 1—Formula 8—thermal topcoat @ 2.0 lbs/ream (0.9 kg/ream)
Layer 2—Formula 7—thermal activecoat @ 2.5 lbs/ream (1.1 kg/ream)
Layer 3—Formula 6—thermal basecoat @ 5.0 lbs/ream (2.2 kg/ream)
Layer 4—Formula 3—microwave susceptor @ 2 lbs/ream (0.9 kg/ream)
Layer 5—paper substrate
Example 4
Layer 1—Formula 8—thermal topcoat @ 2.0 lbs/ream (0.9 kg/ream)
Layer 2—Formula 7—thermal activecoat @ 2.5 lbs/ream (1.1 kg/ream)
Layer 3—Formula 6—thermal basecoat @ 5.0 lbs/ream (2.2 kg/ream)
Layer 4—Formula 4—microwave susceptor @ 3.5 lbs/ream (1.6 kg/ream)
Layer 5—paper substrate
Example 5
Layer 1—Formula 8—thermal topcoat @ 2.0 lbs/ream (0.9 kg/ream)
Layer 2—Formula 7—thermal activecoat @ 2.5 lbs/ream (1.1 kg/ream)
Layer 3—Formula 6—thermal basecoat @ 5.0 lbs/ream (2.2 kg/ream)
Layer 4—Formula 5—microwave susceptor @ 6 lbs/ream (2.7 kg/ream)
Layer 5—paper substrate
Example 5 contained magnesium iodate tetrahydrate (dehydrates at 210° C. as a temperature controlling function).
All samples were tested on Sharp Carousel microwave oven (1200 Watt, 2450 MHz) using the minute plus button.
Reams were 3300 sq. ft. (306.58 sq. meters), 500 sheets, 8.5×11 inches (21.59 cm×27.94 cm).
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A thermally image record material such as a secure document is taught which is susceptible to rapid and bulk destruction of confidential or sensitive information by microwave or high energy absorption. The thermally responsive record material comprises a heat sensitive composition applied onto a substrate having provided thereon in proximity, to the heat sensitive composition as a subcoat or undercoat or back side coating, a layer of particles of an energy receiver material such as a microwave susceptor. Sensitive information imprinted on the record material can be readily destroyed by microwave heating.
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TECHNICAL FIELD
The present invention relates to the catalytic epoxidation of olefins. In particular, the present invention relates to the formation of epoxides from ricinic compounds utilizing oxidizing agents in the presence of phase-transfer catalysts.
BACKGROUND OF THE INVENTION
Photopolymerization or "UV curing" offers a rapid, environmentally compatible and economically attractive method for preparing three dimensional polymer networks. Consequently, UV curing has been widely used for thin film applications such as coatings, inks, and adhesives. Due to the development of diaryliodonium and diarylsulfonium salts as two classes of practical cationic photoinitiators, this area of polymer photochemistry has enjoyed rapid development over the past two decades and has been applied to the polymerization of a wide range of monomer types.
One of the challenges in polymer chemistry is to develop such polymeric materials from inexpensive, environmentally compatible and renewable sources of starting materials while using the least energy input possible.
Previously, unsaturated plant oils have been modified to provide inexpensive monomers which will polymerize rapidly under photoinitiated cationic polymerization conditions. For example, numerous epoxidized triglyceride oils have been utilized as starting materials to make cross-linked polymer networks.
Due to the lack of reactive functionalities, plant oils (e.g., glycerol triesters of unsaturated fatty acids) are not directly amenable to cationic polymerization. However, the olefinic double bonds of these oils can be readily transformed into cationically polymerizable epoxy groups through simple epoxidation reactions. Conventional epoxides and methods for epoxidation have employed oxidation over silver with ethylene, peroxy acids such as peracetic acid in acetic acid solution, organic peroxides, permanganates, chromates, or dehydrochlorination of chlorohydrins with caustic alkenes.
Under ordinary epoxidizing conditions, e.g. utilizing peracetic acid, the yield of epoxidized castor oil is very low. In addition, the use of conventional epoxidizing agents can create safety and environmental concerns. For example, acetic acid is discharged as a polluting by-product.
Catalysts are utilized in the reaction to provide the highest percentage of epoxy groups. Suitable catalysts include heavy metal catalysts such as a tungsten containing heteropolyacid supported on a solid (U.S. Pat. No. 5,430,161 to Brown et al.), catalytic compounds of molybdenum, tungsten, titanium, columbium, tantalum, rhenium, selenium, chromium, zirconium, tellurium, and uranium (U.S. Pat. No. 3,351,635 to Kollar), an acid salt of a peracid of a heavy metal of the group consisting of tungsten and molybdenum (U.S. Pat. No. 2,833,787 to Carlson et al.), a peracid catalyst of the group consisting of the peracids of tungsten, vanadium, and molybdenum (U.S. Pat. No. 2,786,854 to Smith et al.), a compound of a transition metal such as tungsten in the form of tungsten salts or metallo-organic compounds (U.S. Pat. No. 4,197,161 to Friedrich et al.), a catalyst which is a metal of groups IVA, VA, or VIA, preferably molybdenum or tungsten (Belgian Patent 860,776), and a catalyst selected from elementary boron, a mineral or organic derivative of boron, or mixtures thereof (U.S. Pat. No. 4,303,586 to Schirmann et al.).
Other reactions utilize combinations of catalysts or combinations of catalysts and other reagants. These catalysts or catalytic systems include at least one inorganic or organic derivative or compound of mercury and at least one inorganic or organic derivative of transition elements such as tungsten (U.S. Pat. No. 4,026,908 to Pralus et al.), at least one lead compound and at least one compound of a transition metal such as tungsten (U.S. Pat. No. 3,953,480 to Delavarenne et al.), at least one organic tin compound and a second compound selected from molybdenum, tungsten, vanadium, selenium, boron, and mixtures thereof (U.S. Pat. No. 3,806,467 to Watanabe et al.), a transition compound of a metal such as tungsten and a nitrogenous organic base (U.S. Pat. No. 3,778,451 to Poite), tungstic acid and alkaline salts thereof and an onium salt acting as a phase-transfer agent (U.S. Pat. No. 5,336,793 to Gardano et al.), and a catalytic concentration of a peracid of an oxide of a metal from Groups IV, V, VI, or VIII or a peracid of a heteropolyacid and an inorganic or organic alkaline-reacting substance (Great Britain Patent 837,464).
Although these reactions work well for some unsaturated hydrocarbons, success is not universal. One notable exception is castor oil. A review of recent literature contains few references to the preparation of epoxidized castor oil, suggesting that it has found few applications as compared to other epoxidized vegetable oils. In addition, tungsten-based catalysts have previously been recognized as suitable for use with only a few olefins (U.S. Pat. No. 4,973,718 to Buchler et al. and U.S. Pat. No. 4,845,252 to Schmidt et al.).
A need exists for a method for the epoxidation of castor oil and its derivatives using catalysts, either alone or in combination with additional reagents, that produces a high yield of epoxidized castor having sufficient oxirane oxygen content. The epoxidation reaction should avoid side reactions that adversely effect the stability of the oxirane rings by employing a high efficiency catalyst thus permitting shorter contact times. Further, the epoxidized compounds so produced should be particularly well suited for use in cationic photopolymerization reactions to produce three dimensional polymer networks.
SUMMARY OF THE INVENTION
The present invention is directed to the synthesis of epoxidized castor oil (ECO) as an interesting and inexpensive biorenewable monomer by a novel, surprisingly efficient and low cost epoxidation process.
The method of the present invention is a new catalytic method using phase-transfer catalysts. In one embodiment, a novel tungsten peroxo complex based phase-transfer catalyst having onium moieties of suitable lipophilic character is used. In another embodiment, the phase-transfer catalyst is a crown-ether such as 18-crown-6-ether. The new method provides excellent yields of epoxidized castor oil under mild conditions and using an inexpensive, environmentally attractive process. This process can be employed to industrially synthesize epoxidized castor oil which is useful in UV curable coatings, inks, and adhesives. Typically, the epoxidation is rapid, efficient and gives quantitative yields of the desired epoxidized vegetable oils. The epoxidation reaction is also useful for castor oil derivatives such as dehydrated castor oil. As solvents are not required for the epoxidation reaction, solvent removal following epoxidation would not be necessary.
Epoxides are created by the present process by reacting unsaturated or polyunsaturated, conjugated or nonconjugated hydrocarbons with an oxidizing agent including hydroperoxides and monopersulfate compounds in the presence of catalysts that are novel tungsten peroxo complexes. Other additives may be utilized to maintain the pH of the reaction mixture or to increase the yield of the reaction. These additives include pH buffers, alkaline compounds, solvents, extraction agents, caustic agents.
The present invention relates to a method for epoxidizing ricinic compounds comprising combining a ricinic compound and a quaternary ammonium tetrakis(diperoxotungsto) phosphate compound to form a mixture; adding an oxidizing agent to oxidize the mixture and form an epoxide from the ricinic compound; and recovering the epoxide from the mixture. In this method, the oxidizing agent is preferably an aqueous solution of hydrogen peroxide, the ricinic compound is preferably castor oil or a ricinic derivative thereof, and the quaternary ammonium tetrakis(diperoxotungsto)phosphate compound is preferably methyltri-n-octylammonium diperoxotungstophosphate.
The method further comprises heating the mixture to a temperature of about 30-90° C. prior to addition of the oxidizing agent, and then adding the oxidizing agent to the heated mixture with stirring for a sufficient time to allow the compounds to react. Advantageously, the compounds are continuously stirred for up to 8 hours following the addition of the oxidizing agent, and the reacted mixture is allowed to cool to room temperature before recovering the epoxide.
Preferably, the mixture is heated to a temperature of about 60° C., the oxidizing agent is added over the course of about 4 hours, and the resulting mixture is stirred for an additional 4 hours to form the epoxide.
If desired, calcium carbonate can be added to the heated mixture prior to the addition of the oxidizing agent. Then, the oxidizing agent can be added with stirring over the course of up to about 6 hours, the reacted mixture being further stirred for an additional time period of up to about 12 hours, and then the reacted mixture is cooled to room temperature before recovering the epoxide. In this embodiment, the mixture is preferably heated to about 60° C., the oxidizing agent is preferably added over the course of about 2 hours, and the resulting mixture is preferably stirred for about an additional 9 hours.
The present invention is also drawn to a method for epoxidizing ricinic compounds which comprises combining dehydrated castor oil and a phase-transfer catalyst to form a mixture; adding an oxidizing agent to the mixture to form an epoxide from the dehydrated castor oil; and recovering the epoxide from the mixture. The preferred phase-transfer catalyst is a crown ether, such as 18-crown-6-ether, and the preferred oxidizing agent is potassium monoperoxysulfate.
In this method, a phosphate buffer can be added to the mixture before the addition of the oxidizing agent to achieve a pH of between about 6.5-8.5, the mixture then being cooled to about 0 to -10° C., and an aqueous solution of sodium hydroxide is added to the mixture following addition of the oxidizing agent to maintain the pH between about 6.5-8.5. In a more preferred embodiment, the pH is about 7.4 and the temperature is about -5° C. If desired, acetone can be combined with the dehydrated castor oil and phase-transfer catalyst before adding the oxidizing agent thereto, or a solvent can be combined with the acetone, dehydrated castor oil, and phase-transfer catalyst before adding the oxidizing agent thereto. Useful solvents for this purpose include chlorinated hydrocarbons.
The present invention also encompasses the epoxides produced by the previously described processes.
DETAILED DESCRIPTION OF THE INVENTION
The present invention can be used to epoxidize the olefinic group ##STR1## to oxirane ##STR2## in a wide variety of alkenes. The alkenes may vary according to the type and size of the molecule and the location and number of olefinic groups. The olefinic group or groups may be terminal or embedded in the structure.
Olefinically unsaturated and poly-unsaturated compounds which are epoxidized in accordance with the present invention include substituted and unsubstituted, conjugated and nonconjugated, aliphatic, cycloaliphatic, aromatic, and alicyclic olefins including hydrocarbons, esters, alcohols, ketones, or ethers. Suitable compounds include unsaturated fatty acids including oleic, linoleic, palmitoleic, linoleic, vaccenic, gadoleic, ricinoleic, and eleostearic acids, the natural fats and oils which contain them, and the esters of these unsaturated acids. In a preferred embodiment, the alkene includes castor oil and its ricinic derivatives including ricinoleates, ricinoleic acids, ricinoleic acid amides, ricinoleic acid esters, sulfonated ricinoleates, ricinic alcohols, ricinoleyl acids, ricinoleyl acid amides, ricinoleyl alcohols, ricinoleyl alcohol esters, alkali ricinoleates, ricinolamides, hydrogenated castor oil, and mixtures thereof. In a more preferred embodiment, the alkene is castor oil, castor acetate, or dehydrated castor oil. Dehydrated castor oil is commercially available as CASTUNG® oil from CasChem, Inc., Bayonne, N.J.
Castor oil (I) is an inexpensive, biorenewable, large-scale commodity material. Its worldwide production in 1995 alone was 492,254 thousand metric tons. ##STR3##
Native and modified castor oils are currently used in many commercial polymer related applications including: plasticizers, nylon intermediates, and polyurethanes. Further, castor oil is an attractive starting material for the synthesis of monomers and polymers because it contains on the average three hydroxyl and three olefinic groups per molecule that can be utilized for introduction of other types of reactive and polymerizable functional groups.
When castor oil is treated with sulfuric or other strong acids it undergoes facile dehydration to give the highly unsaturated oil known as CASTUNG® oil. A generalized structure for CASTUNG® oil (II) is shown in the following reaction. ##STR4## The detailed structure of CASTUNG® oil is far more complicated than the generalized structure shown. Both conjugated and non-conjugated double bonds are present in the oil. The position and number of conjugated double bonds can vary from molecule to molecule and from sample to sample depending on the method of preparation. For example, one type of CASTUNG® oil II has a ratio of 28:72 of conjugated to non-conjugated double bonds.
The amount of alkene compound to be epoxidized is selected based upon factors such as the desired quantity of epoxide produced, the required oxirane content of the resultant epoxide and the number of olefinic groups contained within the alkene compound. Preferably, the alkene compound is present in a molar excess over the catalyst and oxidizing agent.
Olefinic oxidation to produce oxiranes is achieved by the use of oxidizing agents. These oxidizing agents include hydrogen peroxide and monopersulfate compounds. In one embodiment, the monopersulfate is potassium monoperoxosulfate, commercially available as OXONE® compound from E.I. DuPont De Nemours and Company, Wilmington, Del. When the alkene compound is castor oil, the oxidizing compound is preferably hydrogen peroxide. When the alkene compound is CASTUNG® oil, the oxidizing compound is preferably OXONE® compound.
Aqueous hydrogen peroxide (H 2 O 2 ) solutions of about 30% to about 90% are acceptable. Preferably, solutions of about 30% and about 70% are used. The amount of hydrogen peroxide added to the reaction can be varied depending upon the strength of the H 2 O 2 solution, the amount of alkene compound to be epoxidized, or the desired oxirane content of the epoxide. Preferably in the reaction, the molar ratio of the oxidizing agent to the olefin is selected such that there is a slight excess of the oxidizing agent over the number of double bonds in the olefin. Thus, all of the double bonds ill be epoxidized, yielding the greatest percentage of oxirane oxygen in the epoxide.
In one embodiment of the method, the oxidizing agent is a 30% aqueous solution of hydrogen peroxide, and the ricinic compound includes castor oil. The quaternary ammonium tetrakis(diperoxotungsto)phosphate includes methyltri-n-octylammonium diperoxotungstophosphate. In this embodiment, the mixture is heated to a temperature of about 30-90° C. prior to addition of the oxidizing agent, adding the oxidizing agent with stirring to the mixture over the course of up to about 8 hours, continuously stirring the mixture for an up to additional 8 hours following addition of the oxidizing agent, and allowing the reacted mixture to cool to room temperature.
In another embodiment, the mixture is heated to about 50-70° C., adding the oxidizing agent over the course of up to about 4 hours and stirring the mixture for up to an additional 4 hours. In a more preferred embodiment, the mixture is heated to about 60° C., adding the oxidizing agent over the course of about 4 hours and stirring the mixture for an additional 4 hours.
In another embodiment, the oxidizing agent is a 70% aqueous solution of hydrogen peroxide. In this embodiment, the mixture can be heated to a temperature of about 30-90° C., adding calcium carbonate to the mixture prior to the addition of the oxidizing agent. Further, the oxidizing agent can be added with stirring over the course of up to about 6 hours, followed by stirring of the reacted mixture for an additional time period of up to about 12 hours and cooling to room temperature.
In a more preferred embodiment, the mixture is heated to about 50-70° C., adding the oxidizing agent over the course of up to about 2 hours and stirring for an additional time period of up to about 9 hours. In a more preferred embodiment, the mixture is heated to about 60° C., adding the oxidizing agent over the course of about 2 hours and stirring for an additional time period of about 9 hours.
A novel tungsten peroxo complex can be used as a catalyst. This catalyst is generally a quaternary ammonium tetrakis(diperoxotungsto)phosphate(3-). In a preferred embodiment the catalyst is a tetrahexylammonium tetrakis(diperoxotungsto)phosphate(3-) In a more preferred embodiment, the catalyst is methyltri-n-octylammonium diperoxotungstophosphate (MTTP), represented by the formula [(C 8 H 17 ) 3 N CH 3 ] + 3 {PO 4 [W(O) (O 2 ) 2 ] 4 } 3- .
The epoxidation of castor oil with hydrogen peroxide in the presence of MTTP is depicted in the following equation. ##STR5##
Both 30% and 70% aqueous hydrogen peroxide have been used for this epoxidation. When 70% hydrogen peroxide is used, the level of epoxidation obtained in the final product can be lowered due to competing ring-opening side reactions of the epoxide groups under the reaction conditions. Ring-opening side reactions can be avoided through the incorporation of solid, powdered calcium carbonate in the reaction mixture to control pH. Calcium carbonate is added in an amount sufficient to be present in the reaction in a molar excess to the phase-transfer catalyst. ECO with an oxirane oxygen content of 3.6-3.7% can be obtained by the method of the present invention. Based on this determination, it can be calculated that each ECO molecule contains an average of 2.3 epoxy groups.
Epoxidation of CASTUNG® oil with hydrogen peroxide and the MTTP catalyst is possible, but typically results in an epoxidation efficiency of approximately 60%. During the reaction, should the pH of the reaction mixture fall to 4.0, ring-opening of the initially formed epoxy groups can take place as a major and facile side reaction. Incorporation of solid calcium carbonate into the reaction mixture to control pH is not as effective in increasing the level of epoxidation of CASTUNG® oil as in the epoxidation of castor oil.
The epoxidation of CASTUNG® oil can be achieved using potassium monoperoxysulfate in the presence of the phase-transfer catalyst. Suitable phase-transfer catalysts include the crown ethers. Preferably, the phase-transfer catalyst is 18-crown-6-ether. The addition of acetone helps the reaction proceed smoothly by reacting with the potassium monoperoxysulfate to form an intermediate that epoxidizes. When the pH of the reaction mixture is maintained at 7.4 with the aid of a phosphate buffer, detrimental ring-opening side reactions are avoided. Using potassium monoperoxysulfate as described above, epoxidized CASTUNG® oil (ECT) with an oxirane oxygen content of 6.5% is obtainable. A solvent may also be added to the reaction. Suitable solvents include toluene, hexane and chlorinated hydrocarbons such as dichloromethane. Preferably, the solvent is dichloromethane. Fully epoxidized ECT has a molecular weight of 975.4 g/mol, corresponding to an oxirane oxygen content of 9.8%. Therefore, ECT prepared according to the method of the present invention has approximately four epoxy groups per molecule.
In order to make ECO, castor oil and the phase-transfer catalyst are mixed together. The temperature is raised to about 60° C. Then, an oxidizing agent is added, and the resultant mixture is allowed to cool for up to about 9 hours while the temperature decreases to room temperature. Alternatively, powdered calcium carbonate can be added to the mixture before the addition of the oxidizing agent. Then, the oxidizing agent is added over the course of up to about 2 hours, and the resultant mixture is held at about 60° C. for up to about 9 hours before cooling to room temperature. A solvent such as toluene or chloroform can then be added to extract the product. The organic layer is then separated and dried, and the solvent removed by evaporation.
In order to make ECT, CASTUNG® oil and the phase-transfer catalyst are mixed together. If desired, additional solvents may be added to the mixture at this time. Suitable solvents include acetone and chlorinated hydrocarbons such as dichloromethane. A buffer compound, such as phosphate buffer, is added to the mixture to maintain the pH at about 7.4. The mixture is then cooled to below about 0° C., preferably about -5° C. The oxidizing agent is then added slowly for up to about 4 hours, and a base, such as NaOH in a 2N aqueous solution, is added as well to maintain the pH at about 7.4 during the reaction. The temperature is increased to about 2° C., and the mixture is stirred for up to about an additional 24 hours. The epoxide product is then obtained by filtration, solvent addition, dehydration, and evaporation.
EXAMPLES
ECO and ECT were prepared by the method of the present invention and tested for oxirane content. Castor oil (I) and dehydrated castor oil (CASTUNG® oil,II) were supplied by CasChem, Inc., Bayonne, N.J. OXONE®, 18-crown-6-ether, methyltri-n-octylamine and 30 wt.% hydrogen peroxide were procured from Aldrich Chemical Co., Milwaukee, Wis. Hydrogen peroxide (70 wt. %) was obtained from FMC Corporation, Philadelphia, Pa. MTTP was synthesized according to the procedure reported in literature.
1 H NMR spectra were recorded on a Varian XL-200 spectrometer using CDCl 3 as the solvent and tetramethylsilane (TMS) as an internal reference. Routine infrared spectra were obtained using a MIDAC Model M1300 FTIR. The percent oxirane oxygen of the epoxidized oils was determined according to ASTM D-1652-88.
Example A
Epoxidation of Castor Oil with 30% Hydrogen Peroxide
To a 5 L three-necked flask equipped with a thermometer, addition funnel, condenser and mechanical stirrer were added castor oil (500 g, 0.54 mol) and methyltri-n-octylammonium diperoxotungstophosphate (MTTP, 3 g, 1.33 mmol). The temperature of the reaction flask was gradually brought to 60° C. and 1070 mL (8.7 mol, 30% aqueous solution) hydrogen peroxide was added with stirring over the course of 4 h using the addition funnel. The reaction mixture was vigorously stirred for an additional 4 h before allowing it to cool to room temperature. Toluene (1 L) was added to extract the product and the organic layer separated and dried over anhydrous sodium sulfate. After the removal of the solvent on a rotary evaporator, epoxidized castor oil (ECO) was recovered in 95% yield. 1 H NMR spectrum of the product revealed that 75% conversion of the double bonds to epoxide groups had taken place. The oxirane oxygen content was determined by ASTM method D-1652-90 and found to be 3.6%.
Example B
Epoxidation of Castor Oil with 70% Hydrogen Peroxide
To a 3 L three-necked flask equipped with a thermometer, condenser and mechanical stirrer were added castor oil (500 g, 0.54 mol) and MTTP 3 g, 1.33 mmol). After thoroughly mixing the MTTP and castor oil at 60° C., powdered calcium carbonate (6.65 g, 50 molar excess over MTTP) was introduced and stirred. Hydrogen peroxide (102 mL of 70% aqueous solution) was added drop-wise with stirring over the course of 2 h with the aid of a syringe pump. The reaction mixture was kept at 60° C. under vigorous stirring conditions for 9 h before allowing it to cool to room temperature. Chloroform (1 L) was added to extract the product and the resulting solution dried over anhydrous sodium sulfate. After the removal of the solvent on a rotary evaporator, there were obtained 495 g(90% yield) of ECO. The oxirane oxygen content by titration was found to be 3.7%.
Example C
Epoxidation of Castung® Oil
To a 3 L three-necked flask equipped with a thermometer, condenser, two addition funnels and a mechanical stirrer was added (11.2 g, 0.013 mol) of Castung® oil and 0.25 g (0.95 mmol) of 18-crown-6-ether along with 50 mL each of acetone and dichloromethane. After the introduction of 200 mL of 7.4 pH phosphate buffer, the contents of the flask were cooled to -5° C. and Oxone®(120 g in 500 mL deionized water) was added drop-wise. During the reaction, a 2N aqueous NaOH solution was added drop-wise along with Oxone® to maintain the pH at approximately 7.4. Complete addition to Oxone® required 4 h and thereafter the reaction mixture was stirred overnight at 2° C. The reaction mixture was filtered, diluted with dichloromethane, dried over anhydrous sodium sulfate and the solvents stripped off using a rotary evaporator. There were recovered 11.9 g (96% yield) of epoxidized Castung® oil (ECT). Titrimetric determination gave an oxirane oxygen content of 6.7%.
Although preferred embodiments of the invention have been described in the foregoing description, it will be understood that the invention is not limited to the specific embodiments disclosed herein, but is capable of numerous modifications by one of ordinary skill in the art. It will be understood that the materials used and the chemical details may be slightly different or modified without departing from the methods and compositions disclosed and taught by the present invention.
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Unsaturated or polyunsaturated, conjugated or nonconjugated hydrocarbons are reacted with an oxidizing agent including hydroperoxides and monopersulfate compounds in the presence of phase-transfer catalysts. Suitable hydrocarbons include ricinic compounds such as castor oil and dehydrated castor oil. The phase-transfer catalysts include novel tungsten peroxo complexes, such as quaternary ammonium tetrakis (diperoxotungsto) phosphates, and crown ethers. Other additives opionally utilized include pH buffers, alkaline compounds, and solvents.
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This is a continuation of Ser. No. 711,937, filed Aug. 5, 1976, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to railway cars and in particular to a shear resistant roll restraining means for a freight car.
2. Description of the Prior Art
During rail use of a railway car having a car body including transverse car body bolsters pivotally coupled and supported on transverse truck bolsters, discontinuieties in the track surface, truck hunting and the inertia of the car will cause the car body and therefore the car body bolsters to rock or roll relative to the truck bolsters. If this motion is not restrained or substantially arrested, the rocking motion will cause excessive wear and fatigue fracture of the center plate and bowl pivotally coupling the truck and car body bolsters. Additionally, when the car is operated on marginally serviceable track, excessive oscillatory rocking motion of the car body could cause derailment of the car. Thus, it is necessary to limit and very closely control the magnitude of the relative rocking motion between the truck and the car body bolsters.
The prior art discloses a variety of side bearing structures interposed between the truck and car bolsters to limit or control relative motion therebetween; i.e., U.S. Pat. Nos. 3,400,669 and 3,713,710 both show side bearings mounted on a truck bolster which abutably engage bearing plates depending from an associated car body bolster. As illustrated in U.S. Pat. No. 3,400,669, typically the depending bearing plate structures shown in the prior art are coupled to the upwardly and outwardly sloping bottom webs or plates of the car body bolster by rivets or similar fastening means which extend through the bearing plate support structure and the bolster web at an angle substantially perpendicular to the webs. While this structure clearly couples the bearing plates to the webs, experience has shown that vertical oscillatory impacts of the associated side bearings on the bearing plates develops shearing forces acting on the rivets. These shearing forces tend to bend and ultimately stretch the rivets after extended rail operations. Thus the integrity of the coupling between each bearing plate structure and the bolster web is destroyed and the critical clearance between the bearing plate and its associated side bearing which controls the magnitude of the relative rocking motion therebetween is obviated.
SUMMARY OF THE INVENTION
The present invention relates to a shear resistant car side roll restraining means for a railway car interposed between the truck bolster and an associated car body bolster to limit relative rocking motion therebetween.
The side roll restraining means includes a side bearing upstanding from the truck bolster and an upper side bearing plate structure depending from the upwardly and outwardly sloping bottom web of the car body bolster. The bearing plate structure includes a wedge secured to the bottom web which includes a substantially horizontal lower attachment surface to which the wear plate is secured by vertically extending removable bolts or related fastening means. It should be particularly noted that the removable bolts are vertically aligned and thus extend normal to the attachment surface so that the longitudinal axis of the bolts are coaxial with the direction of the oscillatory impact loading on the wear plate by the lower side bearing. By this means, shearing loads tending to stretch the bolts are essentially eliminated, thereby substantially enhancing the service life of the bearing plate structure.
The invention also discloses vertical shimming means sandwiched between each wear plate and wedge to facilitate vertical adjustment of the critical clearance between each side bearing and bearing plate structure.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an end view of a railway car underframe having shear resistant roll restraining means interposed between the car and truck bolsters in accordance with and embodying the present invention;
FIG. 2 is an enlarged fragmentary view of the roll restraining means shown in FIG. 1; and
FIG. 3 is a fragmentary sectional view taken along line 3--3 of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Turning now to consideration of the drawings and in particular FIG. 1, thereshown is a railway car bolster 1 having upwardly and outwardly sloping bottom web portions 2 supported on the truck bolster 3 of a conventional railway truck or boggie of a type which is well known in the art.
Although the present invention can be used in railway cars with or without center sills, the crosssection of the car underframe shown in the drawings illustrates a railway car underframe having a hat-shaped center sill 4 extending substantially the length of the car between spaced car trucks (not shown). The car bolsters 1 are coupled to the center sill 4 above each truck and extend outwardly therefrom to support side sills 5 extending substantially the length of the car which support the side walls 6 as well as a plurality of longitudinally spaced cross-members extending transversely therebetween. The ends of the truck bolster 3 are supported on truck side frames (not shown) which are in turn carried on the wheels of the truck. The truck bolster includes a center bowl portion 7 which cooperates with and carries a center plate bearing 8 secured to the underside of the car bolster 1 to pivotally support and couple the car bolster 1 to the truck bolster 3.
As discussed above in regard to the prior art, during rail operations discontinuities in the rail surface, truck hunting, the inertia of the car, etc. will cause the bolster to rock or roll relative to the truck bolster. If this motion is not restrained, excessive wear and ultimately failure of the center bearing 8 and bowl 7 will result, and, when the car is moved over particularly poor track, accelerating oscillatory rocking motion could cause derailment of the car. Thus it is necessary to limit and very closely control the magnitude of the relative rocking motion between the car and truck bolsters while at the same time providing a structure which can withstand the extreme fatigue loading characteristic of the railway operating environment.
The preferred embodiment of the present invention discloses a shear resistant roll restraining means 9 interposed between the car and truck bolsters which incorporates an adjustment or vertical shimming means 10 to insure that the critical magnitude of the rocking motion between the car and truck bolsters can be continuously monitored and controlled during field use of the railway car.
The roll restraining means 9 includes a lower side bearing 11 of a variety well known in the art supportably upstanding from the truck bolster 3 and an upper side bearing plate structure 12 depending from the upwardly and outwardly sloping bottom web portions 2 of the car body bolster 1 abutably aligned and spaced above the lower bearing 11 so that during rail operations the upper plate structure 12 and lower side bearing 11 will abutably engage one another and thereby arrest and limit lateral car roll.
As illustrated in the drawings, the upper side bearing plate structure 12 includes a wedge 13 having an upper surface 14 generally conforming to the slope of the bottom web 2 and a horizontal bottom surface portion 15. The wedge 13 is welded as indicated at w about its upper periphery or otherwise separately secured to the bottom web 2. To protect the wedge 13 from wear and to facilitate vertical adjustment of the clearance between the upper bearing plate structure and the lower bearing as will be more specifically discussed hereafter, a replaceable wear plate 16 is secured therebeneath by the nut and bolt combinations 17 which are vertically aligned to extend through the wear plate 16, wedge 13, bottom web portion 2 and the bevel washer 18 which is welded to the upper surface of the web portion 2. It should be particularly noted that since the bolts 17 are vertically aligned and therefore normal to the lower surface 15 of the wedge 13, the impact forces on the upper bearing plate structure 12 during rail use are coaxial with the axis of the bolts 17 such that there are no shearing forces imposed on them. Thus, the invention eliminates shearing forces on the bolts 17 by vertically aligning them with the vertically directed impact forces on the plate 16, thereby preventing bending and stretching of the bolts 17 which would result in loosening of the wear plates 16 and destruction of the critical clearance between the upper and lower bearings which controls the magnitude of lateral car rock or roll.
In the preferred embodiment of the invention the adjustment means 10 comprises a plurality of vertical shims 19 sandwiched between the wedge 13 and plate 16. This feature allows vertical adjustment of the clearance between the bottom of the plates 16 and the top of the lower bearings 11. Since in a typical freight car it may be necessary to maintain this clearance within a fraction of an inch, and because the vertical clearance essentially controls the magnitude of lateral roll of the car body, it is essential that the clearance be very closely monitored and controlled. Additionally, since after extended rail operations the wear plate 16 will wear down and thereby essentially obviate the critical clearance, the shims 19 provide a convenient and inexpensive means of repairing the upper plate structure without having to replace it.
The foregoing description and drawings merely explain and illustrate the invention and the invention is not limited thereto, except insofar as the appended claims are so limited, as those skilled in the art who have the disclosure before them will be able to make modifications and variations therein without departing from the scope of the invention.
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A shear resistant roll restraining means for arresting lateral rolling motion of a railway car including a side bearing upstanding from the truck bolster, a bearing plate structure vertically aligned and abuttably engageable with the side bearing depending from the upwardly and outwardly sloping bottom web of the car body bolster, and a bearing plate coupling having a longitudinal axis extending substantially coaxial with the direction of oscillatory impact loads of the side bearing on the bearing plate.
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[0001] This application claims the benefit of U.S. Provisional Application No. 60/226,150 filed Aug. 16, 2000 and entitled Method and Apparatus for Secure Communication Over Unstable Public Connections, the entire content of such Application being expressly incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to the field of data communication between computer systems. More specifically, it relates to a method of communication between a local computer system potentially protected by a firewall and a remote computer system connected to the local system via a public network.
[0004] 2. Background Information
[0005] In the field of communications many systems exist for passing data from one point to another. A typical communication system consists of several layers. A low-level layer might include software designed to drive hardware devices, such as modems or Ethernet interface cards. An example of a fully featured top-level software transport layer that is designed to provide reliable end to end communications is the TCP/IP protocol. Computer Networks, by Andrew S. Tanenbaum, printed by Prentice Hall PTR, Upper Saddle River, N.J. 1996, provides a more detailed view of computer networks, TCP/IP and the OSI model.
[0006] This invention builds upon a number of established systems that can be readily understood by one skilled in the art. These systems are summarized as follows:
[0007] Protocol encapsulation: This is a technique where high-level communication messages are packaged into the payload of a lower level communication system. One example of this is the manner in which TCP/IP messages are packaged into Ethernet packets for communication over a local area network (LAN). In a similar way TCP/IP can be packaged into Frame Relay packets for communication over wide area networks (WAN), or into serial streams for communication over networks such as the Internet. Protocol encapsulation can also be application-specific, as described in Batz et al., U.S. Pat. No. 5,918,022 entitled Protocol for Transporting Reservation System Data Over A TCP/IP Network. The present invention, while possessing some limitations, is intended for general use and is not necessarily tied to any specific application.
[0008] TCP/IP: This basic communications medium is described in detail in the above referenced work by Tanenbaum and provides a reliable point-to-point communication system that applications can use to communicate. Protocol encapsulation methods have been written that can encapsulate TCP/IP requests into just about every conceivable low-level network transport, including Ethernet and PPP.
[0009] HTTP and HTTPS: HTTP is a high-level protocol that builds upon TCP/IP and was designed specifically to carry content between Web sites and Web browsers. HTTPS is a secure implementation of HTTP that is used for transmitting sensitive data such as credit card details.
[0010] HTTP firewalls and Proxies: With recent advances in electronic communications, corporations have begun to use public networks, specifically the internet, for internal communications, communications with clients, and for accessing public data stores such as third-party web sites. Corporations are normally connected to the Internet through dedicated communications links that are available on a permanent basis. However, Internet connectivity poses a great security risk to a corporation: any machine with a known address that can access the Internet is in turn accessible from any other machine on the Internet. To prevent unwanted third-party access, most corporations, and some individuals, deploy firewalls to secure their sites. A firewall is a computer software and hardware solution that allows communications to be originated only from within the secure site. For example, most firewalls allow outgoing HTTP traffic (Web page requests) and incoming replies to messages originated within the site (Web pages). Email is often allowed to pass directly into a secure site as it intended to be a passive form of communication. This ability to allow limited communication is often performed by a proxy. A proxy is a forwarding agent that receives a request for information from a computer within the secure site, passes it to a destination, and returns any responses to the originator. The combination of a firewall preventing access to machines within a secure site, and a proxy masking a secure machine's true identity, provide a level of security which most demand. Some corporations impose an even higher level of security by restricting, or denying completely, certain forms of outgoing communication. For example, many corporations permit only small amounts of data to be sent through their firewalls; this can be accomplished by denying HTTP POST requests and disabling all other upload protocols, such as FTP. More details can be found in Coley et al., U.S. Pat. No. 6,061,798 entitled, “Firewall System for Protecting Network Elements Connected To A Public Network.”
[0011] Tunnels: With the deployment of firewalls and proxies it became impossible, or at least quite difficult, to provide a bi-directional communication system between a computer within a secure site and another computer on the Internet. Several solutions exist that require special bypasses or tunnels to be added to firewalls, but these typically require additional applications to be executed on the firewall host. This is at the least an inconvenience, and often prohibited due to security considerations. For more detail, see Jade et al, U.S. Pat. No. 6,061,797 entitled “Tunnels Outside Access To Computer Resources Through A Firewall”; Birrell et al, U.S. Pat. No. 5,805,803 entitled, “Secure Web Tunnel,” and Aziz et al., U.S. Pat. No. 5,548,646 entitled, “System For Signatureless Transmission And Reception Of Data Packets Between Computer Networks.” The present application describes a system that does not deploy anything on a firewall host, and yet allows reliable two-way communications between local and remote applications using only HTTP. As discussed above, HTTP requests are normally successfully proxied through firewalls.
[0012] Encryption: While the present embodiment of the invention makes use of encryption to provide secure communications, it should be clear to one skilled in the art that any one of a number of available techniques could be used, and the invention is not dependent on the exact method used. It should also be apparent that a non secure embodiment of the invention is possible by not using encryption. For example, in one embodiment the process described in Hellman, et al., U.S. Pat. No. 4,200,770 entitled, “Cryptographic Apparatus and Method,” might be used.
SUMMARY OF THE PRESENT INVENTION
[0013] Methods and apparatus are disclosed which provide a system for secure and reliable communication between a pair of client computers, or a plurality of client computers residing on separate private networks, and connected via a public network such as the Internet. The communications described herein are designed to function even if a persistent link can not be established between the communicating computers. Further, the system described herein is designed to traverse any locally installed gateways or firewalls to obtain communicative access to a remote destination.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] [0014]FIG. 1 generally depicts an environment in which the present invention may be deployed;
[0015] [0015]FIG. 2 is a diagram schematically illustrating the architecture of a client application and associated data processor in accordance with the present invention;
[0016] [0016]FIG. 3 is a diagram schematically illustrating one embodiment of the data processor architecture used in accordance with the present invention;
[0017] [0017]FIGS. 4 a and 4 b illustrate the composition of a data packet constructed and sent by a local computer in accordance with the present invention;
[0018] [0018]FIG. 5 illustrates one embodiment of the composition of an aggregated data packet constructed and sent by a public computer as a reply to a message from a local computer in accordance with the present invention;
[0019] [0019]FIG. 6 illustrates an embodiment of the composition of an HTTP POST encapsulated data packet for transmission from a local computer to a remote computer through a firewall in accordance with the present invention;
[0020] [0020]FIG. 7 illustrates an embodiment of the composition of an HTTP GET encapsulated data packet for transmission from a local computer to a remote computer through a firewall in accordance with the present invention;
[0021] [0021]FIG. 8 illustrates one embodiment of the composition of an individual reply data packet after it is received and unpacked by a local computer in accordance with the present invention;
[0022] [0022]FIG. 9 depicts a flow chart generally illustrating an embodiment of the process by which data is processed, encapsulated and transmitted from a local computer in accordance with the present invention;
[0023] [0023]FIG. 10 is a flow chart generally illustrating an embodiment of the process by which a local computer implementing the process of FIG. 9 splits a message originating at the local computer system into suitably-sized chunks and packages it according to FIG. 4 for transmission in accordance with the present invention;
[0024] [0024]FIG. 11 depicts a flow chart generally illustrating an embodiment of the process reply substep of FIG. 9 wherein encapsulated data packets (FIGS. 6,7) received by a local computer are processed in accordance with the present invention;
[0025] [0025]FIG. 12 is a flow chart generally illustrating an embodiment of the packet separating substep of FIG. 11 wherein payload message segments are extracted from an aggregated data packet (FIG. 5) and individual data packets (FIG. 8) are assembled in accordance with the present invention;
[0026] [0026]FIG. 13 depicts a flow chart generally illustrating an embodiment of the process by which a public application sends data in accordance with the present invention;
[0027] [0027]FIG. 14 depicts a flow chart generally illustrating an embodiment of the process by which a public computer system may request information from a local computer system;
[0028] [0028]FIG. 15 is a flow chart generally illustrating an embodiment of the process by which a public computer receives and processes data in accordance with the present invention;
[0029] [0029]FIG. 16 is a flow chart generally illustrating an embodiment of the process message step of FIG. 15 by which the public computer processes pending data into a reply to a received message in accordance with the present invention;
[0030] [0030]FIG. 17 is a flow chart generally illustrating an embodiment of the recombine data substep of FIG. 15 by which a public computer recreates a message from its constituent chunks in accordance with the present invention;
[0031] [0031]FIG. 18 is a flow chart generally illustrating an embodiment of the package data substep of FIG. 16 by which a public computer concatenates message segments into a composite payload message for transmission as a reply to a message received from a local computer in accordance with the present invention;
DETAILED DESCRIPTION OF THE INVENTION
[0032] In the following description, various aspects of the present invention are described. However, it will be apparent to those skilled in the art that the present invention may be practiced with only some or all aspects of the present invention. For the purposes of explanation, specific numbers, materials and configurations are set forth to provide a thorough understanding of the present invention. However, there it will also be apparent to one skilled in the art that the present invention may be practiced without the specific details. In some instances, well known features are omitted or simplified in order not to obscure the present invention.
[0033] Parts of the description are presented in terms of operations performed by a computer system, using terms such as data, values, characters, strings, numbers and the like, consistent with the manner commonly employed by those skilled in the art to convey the substance of their work to others skilled in the art. As is well understood by those skilled in the art, these quantities take the form of electrical, magnetic, or optical signals capable of being stored, transferred, combined, and otherwise manipulated through mechanical and electrical components of the computer system. The term computer system as used herein includes general purpose as well as special purpose data processing machines, systems, and the like, that are standalone, adjunct or embedded.
[0034] Various operations are described as multiple discrete Steps in turn, in a manner that is most helpful in understanding the present invention, however, the order of description should not be construed as to imply that these operations are necessarily order dependent. In particular, all operations need not be performed in the order of presentation.
Description of FIG. 1
[0035] In FIG. 1, the environment in which the present invention may be deployed is shown. This environment is typically comprised of a local computer system 10 , which may include a local computer 11 , on which part of the present invention resides, connected by a private network 12 , through a firewall 16 to a public network 18 , such as the Internet. This connection may be unstable, in the sense that the data path may inadvertently be interrupted from time-to-time. Another part of the present invention resides on a public computer 20 , which may be a component of a remote computer system 21 , that is connected directly to the public network 18 .
Description of FIG. 2
[0036] It is well known to those skilled in the art that the general architecture of client applications may consist of client application code, linked with third-party application libraries. In FIG. 2, the architecture utilized in accordance with the present invention is shown generally at 22 . As depicted, the client application 24 is linked via an Application Programming Interface (API 23 ) to a specially configured data processor 26 . As is also well known to those skilled in the art, the actual form of the API may be configured to provide an unlimited number of different views of the processor to fit pre-existing application code architectures. The processor 26 makes use of the HTTP protocol and the TCP/IP protocol described above.
Description of FIGS. 3 and 4 a.
[0037] [0037]FIG. 3 depicts generally at 27 the overall architecture of the present invention. In one embodiment the processor 26 may be implemented in computer hardware. In another embodiment the processor 26 may be implemented as computer software. It should be clear to those skilled in the art that the processor 26 could also be a combination of both, without limitation as to which portion of the architecture is implemented in hardware or software.
[0038] Data intended to be included in a transmittable Local Message is schematically represented by the block 50 in FIG. 4 a . This data enters and exits the processor 26 in the local computer through the connections 25 to the API buffers 31 and 34 on one side thereof, and after being encrypted, packaged, and encapsulated for transmission, the data leaves the processor through communications buffer 32 on the other side and enters the transporting network(s) 30 . Data entering the processor from the transport side is received by the buffer 36 and after the encapsulation is removed, is decrypted and unpackaged, and then placed in the API receive buffer 34 . In processor 26 , the API send buffer 31 , data send buffer 32 , API receive buffer 34 and data receive buffer 36 all provide temporary storage means for data in transit.
[0039] An encryption unit 38 is responsible for encrypting and decrypting the message data. A packaging unit 40 operates under control of control logic 44 and is responsible for dividing the encrypted local message data into “chunks” 52 (FIG. 4 a ) of predetermined size, and for combining the chunks with identifying header data 54 (FIG. 4 b ) to form data packets 4 H, as will be described below. Packaging unit 40 also performs an unpacking operation with respect to received data. An addressing unit 42 is responsible for encapsulating the outgoing data packets to fit the transport protocol requirements for data transmission, and for stripping incoming encapsulated packets of their encapsulation, as will be described below.
[0040] In accordance with the present invention, another processor 26 ′ resides on the public computer 20 (FIG. 1) and is substantially identical to that of the local computer described in the upper part of FIG. 3. Entities 31 ′ through 44 ′ are functionally identical to entities 31 through 44 .
Description of FIG. 4 b
[0041] [0041]FIG. 4 b illustrates one configuration of the components of a data packet transmitted from a local computer 11 to a public computer 20 after packaging but before encapsulation. It will be clear to those skilled in the art that the order in which the components of the packet are assembled is unimportant, as is the exact nature and number of the components. Component 4 A is an identification number unique to the local message, identifying the local message on both the local computer 11 and the public computer 20 . 4 B is the number of chunks in which the original local message is divided for transmission from the local computer 11 according to the present invention,. 4 C is the chunk number of this instance of the message as determined by a process explained below. 4 D is the identification (ID) of the sender of the particular message, and 4 E is the identification (ID) of the destination. 4 F specifies which remote message this local message is a reply to, if in fact it is a reply to a previously received message from the public computer 20 . If this message is not a reply, then this ID will be null. 4 G represents the payload of the data packet. As suggested above, the payload may be an entire message to be sent, or if the length of the message exceeds the limits of the firewall 16 (FIG. 1), a partial message, or chunk.
Description of FIG. 5
[0042] [0042]FIG. 5 illustrates one configuration of either an Aggregated Data Packet in which is included either an original message or a reply message to be transmitted through the firewall from a public computer 20 to a local computer 11 . As described above, the Payload of this packet can also be an aggregation of multiple messages, or message segments, to be sent at the same time to the local computer. This packet is comprised of a header in which component 5 A specifies the Number of Messages, or “Payload Segments”, in the Aggregated Data Packet contained within the transmission, and 5 B and 5 C identify the Sender and the receiver (Destination) respectively. For each included Payload Segment, a Segment Identification Number 5 D, its Length 5 E, and the Identification Number 5 F of the Local Message to which it is potentially a reply, is specified. The Payload 5 G of this packet includes a concatenation of all of the Message Segments (of which three, 5 G 1 , 5 G 2 & 5 G 3 are shown) to be communicated by the packet.
Description of FIG. 6
[0043] [0043]FIG. 6 shows the format of one embodiment of an encapsulated data packet to be sent from a local computer 11 to a public computer 20 . In this embodiment, it is assumed that the HTTP POST operation is allowed with regards to the security policy enforced at the site where the local computer resides. The HTTP Address 6 A contains the address of the public computer 20 written according to the HTTP syntax. The Header 6 B contains fields required by the HTTP protocol, such as the total message length in bytes. The payload 6 C is comprised of a data packet of the configuration illustrated in FIG. 4 b.
Description of FIG. 7
[0044] [0044]FIG. 7 shows an alternative embodiment of an encapsulated message to be sent from a local computer 11 to a public computer 20 . In this embodiment, it is assumed that only HTTP GET operations are permitted with regards to the security policy enforced at the site where the local computer 11 resides. In this case, the entire Data Packet (or portions thereof) need to be transmitted as part of one or more Encapsulated Data Packets each having an HTTP address specified in a GET command. Such addresses are nonexistent, but the public computer knows how to decode these addresses into a useful message.
Description of FIG. 8
[0045] [0045]FIG. 8 shows one embodiment of an Unpacked Data Packet 8 F in the form received by the local computer 11 after the Aggregated Data Packet (FIG. 5) is decomposed (as illustrated in FIG. 11 below) in accordance with the present invention. As depicted, the message is delivered to the client application 24 in a packet form including a Message (payload segment) ID 8 A, a Sender ID 8 B, a Destination ID 8 C, a Local Message ID 8 D to which this message is a Reply, and the Message Segment 8 E.
Description of FIG. 9
[0046] Referring now to FIG. 9, as well as previously described figures, when a client application running on a local computer 11 of the local computer system 10 needs to transmit data (a message) to a remote public computer 20 , the application 24 (FIG. 2) in Steps 9 A and 9 C uses the associated API to deposit blocks of information in the API send buffer 31 , such information including the data to be communicated (“local message”), the sender address, the destination address, and the reply to message ID. A stimulus (Step 9 B) is then applied to the control logic 44 by the client application to abort the waiting (Step 9 J) and trigger data processing. A stimulus is a request to cut short the wait period ( 9 J). An example of such a request might be any internal or external event the occurrence of which triggers the immediate processing and sending of the data payload in buffer 9 C via 9 E- 9 I.
[0047] In Step 9 E, the message data present in the API send buffer 32 is encrypted by the encryption unit 38 , using an appropriate encryption mechanism, to obtain encrypted data.
[0048] In Step 9 F of the preferred embodiment, the packaging unit 40 splits the encrypted message data into small “chunks”, as illustrated above in FIG. 4 a and described below with respect to FIG. 10, to accommodate the firewall restrictions of the communication path with regards to the permissible amount of data transmitted in a single message.
Description of FIG. 10
[0049] Skipping ahead momentarily to FIG. 10 which illustrates in more detail the packaging process of Step 9 F, it will be noted that in Step 10 C the packaging unit 40 (FIG. 3) looks at the encrypted local message ( 10 A) and then, depending on the firewall imposed limit on the length of message allowed, calculates the number “N” of chunks necessary for the current block (FIG. 4 a ) of Local Message Data. For example, N=(Local Message size)/(maximum message size−header size) rounded up. The data is then split into data chunks, each chunk is numbered at step 10 E, and the Local Message ID 4 A and the Number of Chunks 4 B are prepended at Step 10 F. The packaging unit then increments the local message ID in Step 10 G and preprocesses the next message. More specifically, the packaging unit 40 assembles each chunk of the encrypted Local Message Data into a Data Packet 4 H including, as illustrated in FIG. 4 b,
[0050] (1) the Local Message ID Number ( 4 A) common to all chunks of the same encrypted block of message data,
[0051] (2) the Number N of Chunks ( 4 B) required to form the original encrypted block of message data, and
[0052] (3) the current chunk sequence number (Chunk Number 4 C).
[0053] Reverting now to FIG. 9, in Step 9 F, to complete the packet header 54 (FIG. 4 b ), the following addressing items are duplicated into each Data Packet 4 H:
[0054] (4) the local computer's address (Sender ID 4 D);
[0055] (5) the public computer's address (Destination ID 4 E); and
[0056] (6) an identification of any message to which this data is a response, if applicable, (Reply To Remote Message ID 4 F).
[0057] In an alternative embodiment of the present invention wherein a firewall 16 does not restrict the amount of data transmitted in a single message, packaging unit 40 augments the encrypted but undivided block of message data with a simpler header including:
[0058] (1) the Local Message ID Number;
[0059] (2) the local computer's identification (Sender ID);
[0060] (3) the public computer's identification (Destination ID); and
[0061] (4) an identification of the message to which this data is a response, if applicable, (Reply To Remote Message ID).
[0062] In Step 9 G, the Data Packets are encapsulated into HTTP POST messages, or HTTP GET messages (depending on whether or not the security policy implemented by the firewall allows POST messages to traverse to the public network). If POST messages are allowed, the addressing unit 42 adds to the Data Packet an HTTP address and an HTTP header (as explained above with respect to FIG. 6). If POST messages are not allowed, the addressing unit inserts the Data Packet into one or more HTTP GET messages as described above and shown in FIG. 7.
[0063] In Step 9 H, the Control logic 44 then deposits the resulting Encapsulated Data Packet into the send buffer 32 (FIG. 3) where it is made available for transmission to the public computer 20 via connections to transport 30 . Typically, this will establish a connection to the public computer (or the firewall if present) to which the message will be transmitted. The connection is then maintained until a reply is returned. This process can be carried out by any number of available web communication standard libraries.
[0064] When a reply is received from the public computer 20 via the firewall 16 , the reply is processed in Step 9 I as further described below with respect to FIG. 11.
Description of FIG. 11
[0065] [0065]FIG. 11 illustrates an embodiment of the program flow in accordance with the present invention which implements the processing of a reply to a message that was previously sent out to a public computer by a client application resident in the local computer. As in the processing and transmission of the messages originating at the local computer, the reply messages originating at the remote computer may also be encapsulated in an HTTP protocol package including HTTP header information describing the following content. When the reply message is received from the public computer 20 via the connections to transport 30 and over the established connection, the encapsulated message is placed in the receive buffer 36 (FIG. 3) as indicated at 11 A.
[0066] In Step 11 B the encapsulation is stripped from the received data packet and discarded leaving the Aggregated Data Packet (FIG. 5). The Packet is tested at 11 C to determine whether or not it includes compound data, i.e., multiple Message Segments. If not, the payload is decrypted and processing continues. If the Packet is compound, then it is unpackaged as set forth in FIG. 12.
Description of FIG. 12
[0067] [0067]FIG. 12 is a block diagram illustrating the Public Compound Reply message separation process invoked in Step 11 D. When a message is received from the remote public computer 20 in the form of an Aggregated Data Packet, illustrated in FIG. 5, the packaging unit 40 selects the first Message Segment ( 5 G 1 in FIG. 5) identified by the header component, Message Segment ID Number 5 D 1 . In Step 12 C, the packaging unit 40 forms a new data header by concatenating the Sender ID 5 B 1 and the Destination ID 5 C 1 . The packaging unit 40 then prepends (at 12 D) the Segment ID Number 5 D 1 and then at 12 E, appends the Reply to Local Message ID 5 F 1 to form the new header. It then appends the selected Message Segment 5 G 1 to the header to form an individual Reply Data Packet 8 F (as illustrated in FIG. 8).
[0068] To recap the above, the Aggregated Data Packet is comprised of several individual component parts. In Step 11 D the packaging unit 40 unpacks the received Aggregated Data Packet and reconfigures it into a plurality of individual Reply Data Packets 8 F including:
[0069] a header comprised of
[0070] (1) a Message Segment ID Number ( 8 A);
[0071] (2) a Sender ID ( 8 B);
[0072] (3) a Destination ID ( 8 C); and
[0073] (4) a Reply to Local Message ID ( 8 D); and a payload including
[0074] (5) a Message Segment ( 8 E).
[0075] Returning now to FIG. 11, in Step 11 E, the encryption unit 38 (FIG. 3) decrypts the Message Segment of each individual Packet and discards simple Acknowledgements ( 11 F) before depositing the Reply Data Packets into the API receive buffer 34 at Step 11 G. The control logic 44 then informs (at 11 H) the application 22 , via the connections to the API 23 , of the presence of the decrypted Reply Data Packet in the receive buffer.. The program flow then proceeds to the send sequence (Step 9 D of FIG. 9).
[0076] It is well known to those skilled in the art that the remote public computer 20 cannot initiate a communication with a client, or local, computer 11 that is protected from the public network 18 by a firewall 16 using the HTTP communications protocol.. Therefore, all messages sent by the remote computer 20 to the local computer 11 must be in the form of responses to requests originated from the local computer 11 .
[0077] Description of FIG. 13
[0078] Accordingly, in order to send a properly formatted block of data (Aggregated Data Packet) to local computer 11 , the public computer 20 must first place the data block in its API send buffer 31 ′ as indicated in Step 13 B. It should be noted however, that this data is not sent immediately, but must wait for a communication from the local computer 11 before actual transmission back to the local computer.
Description of FIG. 14
[0079] [0079]FIG. 14 is a flow diagram illustrating a situation wherein it is urgent that data stored in the API send buffer 31 ′ be sent without further delay. In such a case, the control logic 44 ′ (FIG. 3) generates a stimulus. In accordance with the present invention, the stimulus may, for example, be an e-mail message sent from the public computer 20 to the local computer 11 through usual e-mail communication channels which, incidentally, pass freely through the firewall. Upon arrival at the local computer 11 , the processing of the e-mail message will prompt the local computer that a message is waiting to be sent from the public computer 20 , and in response, a stimulus ( 14 G) will be generated causing immediate processing of the message in API Send Buffer 31 ′ (Step 13 B).. Otherwise, the control logic 44 ′ will cause the system to wait (Step 14 F) until a predefined period of time expires, at which time a stimulus is generated, as described above.
Description of FIG. 15
[0080] When a message is received ( 15 A) by the public computer during the waiting period (FIG. 14), the processing of the received message is engaged, and the packaging unit 40 ′ strips the HTTP encapsulation from the received message (Step 15 B), and determines whether or not there are any complete messages presented. If so, the header data and message data are recombined in Step 15 E as is more clearly depicted in FIG. 17.
Description of FIG. 17
[0081] Jumping ahead, FIG. 17 illustrates the message recombination process of Step 15 E. After receiving a message, and after the addressing unit 42 ′ has stripped the HTTP wrapper from the message, the packaging unit 40 ′ (in public computer 20 ) waits until it has received N chunks of data ( 17 C); N being specified in the message packet. Once all N chunks are received, the packaging unit forms a data header (Step 17 E) comprising:
[0082] (1) Message Segment ID number;
[0083] (2) Sender ID;
[0084] (3) Destination ID and;
[0085] (4) Reply to Local Message ID. Then it concatenates ( 17 F) all of the data chunks into one Message Segment ( 8 E in FIG. 8).
[0086] Returning to Step 15 C in FIG. 15, wherein the packaging unit 40 ′ assesses the completeness of the message, it will be understood that the data segment can be complete message or a portion of a multi-part message as described above with respect to FIG. 10. If no complete message can be formed from the contents of the receive buffer 36 ′, the connection is closed and the wait is resumed for more incoming messages. As soon as a complete message can be formed, the packaging unit 40 recombines all chunks and forms an individual data packet (Step 15 E). The data part of the packet is then decrypted by the encryption unit 38 ′ (Step 15 F) and the control logic 44 ′ deposits the decrypted data packet in the API receive buffer 34 ′ (Step 15 G) and informs the application (Step 15 H) that a message is pending retrieval via connections 25 ′ to the API.
[0087] To ensure that every message from the local computer 11 receives an answer, the control logic 44 ′ places an acknowledgement (ACK) in the API send buffer 31 ′ (Step 15 I), and in Step 15 K, processes the messages in the API send buffer as described above with respect to FIG. 16. The public computer then terminates the connection and resumes a wait for new messages as indicated by Step 15 D.
Description of FIG. 16
[0088] To transmit pending data from the public computer 20 to a local computer 11 over a currently established communication channel, the encryption unit 38 ′ encrypts the data (Step 16 B) present in its API send buffer 31 ′. In Step 16 C, the packaging unit 40 ′ aggregates all encrypted segments of the message data in the API send buffer 31 ′ into a single payload, (as described more specifically below with respect to FIG. 18), and in Step 16 D adds address and other header data to develop an Aggregated Data Packet ( 5 H) as described above with respect to FIG. 5,. The control logic 44 ′ then deposits the Aggregated Data Packet in the send buffer 32 ′ and transmits it as a reply to the message last received from the local computer 11 (Step 16 E). The control logic 44 ′ then clears the API send buffer 31 ′, and at Step 16 F, returns to the receive sequence at Step 15 C (FIG. 15).
Description of FIG. 18
[0089] [0089]FIG. 18 depicts the packaging process Step 16 C of combining multiple data segments ( 5 G of FIG. 5) and associated header data ( 5 A- 5 G) into one single message block (Aggregated Message Packet 5 H) to be transmitted from the public computer 20 to the local computer 11 as a reply message. In Step 18 C the packaging unit 40 ′ forms the packet header by concatenating the Number of Message Segments 5 A about to be sent, the Sender ID 5 B and the Destination ID 5 C. At Step 18 D, the packaging unit 40 ′ adds to the header in sequence, the Segment ID Number 5 D, the Segment Length 5 E, and the Reply to Local Message ID 5 F for each Message Segment 5 G about to be sent in this packet. At Step 18 E, the encrypted data forming each Message Segment to be transmitted is concatenated and added to the packet being formed, to eventually obtain the Aggregated Data Message 5 H.
[0090] Although the present invention has been described in terms of specific embodiments, it is anticipated that alterations and modifications thereof will no doubt become apparent to those skilled in the art. It is therefore intended that the following claims be interpreted as covering all such alterations and modification as fall within the true spirit and scope of the invention.
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Methods and apparatus are disclosed which provide a system for secure and reliable communication between client computers residing on separate private networks but connected via a public network such as the Internet. The communications described herein are designed to function even if a persistent link can not be established between the two computers. Further, the systems and apparatus described herein are designed to traverse any locally installed gateways or firewalls to obtain access to a remote destination.
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FIELD
The present disclosure relates to vent assemblies for motor vehicles and, more particularly, to a locking mechanism to retain a cover in position.
BACKGROUND
In motor vehicles, such as motor coaches, which include a living area, it is desirable to have a vent assembly which enables the interior of the coach to vent. Ordinarily, a vent assembly is utilized with a fan that is capable of moving air either into or out of the interior of the motor coach. One such vent assembly is illustrated in U.S. Pat. No. 4,633,769 entitled “Roof Vent Fan Assembly”.
Ordinarily, when the motor coach is being driven, the cover of the vent assembly is in the down position. The vent assemblies usually include an arm to raise and lower the cover between an open and closed position.
The disclosure provides a lock assembly to retain the cover in position during movement of the vehicle. The disclosure provides a locking mechanism which moves between an open and closed position to retain the cover in position during motion of the vehicle. The disclosure provides a fan assembly with a two point retention system to retain the cover in position during motion of the vehicle.
SUMMARY
According to a first aspect of the disclosure, a vent assembly comprises a base with an optional rotatable fan assembly mounted on the base to rotate a fan blade in the base. A cover is movably coupled with the base such that it moves between an open and a closed position. A locking mechanism is associated with the base. The locking mechanism includes a latch and a linkage coupled with the latch to move the latch between a locked and an unlocked position. A member extends from the cover. The member cooperates with the latch such that when the latch is in a locked condition, the cover is secured with the base in a closed position. When the latch is in an unlocked condition, the cover is enabled to be pivoted away from the base into an open position.
Accordingly to a second aspect of the disclosure, the locking mechanism is provided for use with a vent assembly including a base and a cover. The locking member comprises a latch and a linkage coupled with said latch. The linkage moves the latch between a locked and an unlocked position. A member extends from the cover. The member cooperates with the latch such that when in a locked condition, the cover is locked with said base in a closed position. When the latch is in an unlocked condition, the cover is enabled to pivot away from the base to its open position. The latch is hook shaped and includes a ramped surface. The member is a post extending from the cover which can be formed unitarily with the cover. The post includes a head with a planar surface which is contacted by the ramp surface of the latch. The linkage has two ends. The latch is secured at one end of the linkage and a handle is secured at the other end. The linkage includes a rotatable rod coupled to the latch.
Accordingly to a third aspect of the disclosure, a vent assembly includes a two point cover locking mechanism. A cover is movably coupled with a base between an open and a closed position. A locking mechanism is associated with the base. The locking mechanism includes a latch and a linkage coupled with the latch. The linkage moves the latch between a locked and an unlocked position. A member extends from the cover. The member cooperates with the latch such that when the latch is in a locked condition, the cover is secured with the base in a closed position. When the latch is in an unlocked condition, the cover may pivot away from the base to an open position. An arm is coupled with the cover. The arm raises and lowers to move the cover between its open and closed position. The arm is positioned adjacent the fan on one side of the base. The locking mechanism is positioned on a side opposite to that of the arm. The latch is hook shaped and includes a ramped surface. The member is a post extending from the cover which can be formed unitarily with the cover. The post includes a head which has a planar surface which is contacted by the ramp surface of the latch. The linkage has two ends with the latch at one end and a handle at the other end. The linkage includes a rotatable rod coupled to the latch.
Further areas of applicability will become apparent from the provided description. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.
DRAWINGS
The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way.
FIG. 1 is a perspective view of a vent assembly with a locking mechanism.
FIG. 2 is a perspective view from inside of the base with the locking mechanism in a first closed position.
FIG. 3 is a view like FIG. 2 , with the locking mechanism in an opened position.
FIG. 4 is a perspective view of the locking mechanism secured on the post of the cover assembly.
FIG. 5 is a perspective view of the locking assembly in an open position.
FIG. 6 is an elevation view of a portion of FIG. 4 .
DETAILED DESCRIPTION
The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses.
Turning to the figures, particularly FIG. 1 , a vent assembly is illustrated and designated with the reference numeral 10 . The vent assembly includes a base 12 and a cover 14 pivotally attached to the base 12 . An arm mechanism 16 pivots the cover 14 between an open and closed position. A locking mechanism 18 is associated with the base 12 .
A fan 20 and motor 22 are optionally mounted in a cylindrical opening 24 in the base 12 . The base 12 includes a peripherally extending deck 26 which enables the base 12 to be mounted on a surface of the vehicle. The base 12 includes an upper portion 28 which enables securement of the cover 14 , generally via a hinge (not shown), with the base 12 . Also, a seal 30 is positioned about the periphery of the free end of the upper portion 28 . The base 12 includes a lower portion 32 which enables the fan assembly 10 to fit through an opening in the vehicle.
The arm 16 is secured with a bracket 34 . The bracket 34 is secured to extending members 36 on the cover 14 . The bracket 32 includes a slot 38 to enable an arm pin to slide within the slot 38 so that the cover 14 is moved between its open and closed position.
The locking mechanism 18 includes a latch 40 . The latch 40 is connected with a linkage 42 . The other end of the linkage 42 includes a handle 44 . The latch 40 is an overall C or U shaped hook. The latch 40 tapers peripherally from its connection with the linkage 42 to its free extending end 46 as best seen in FIG. 5 . An opening 48 is defined between the free end 46 and the connection end 50 of the hook. The latch free end 46 includes a ramp surface 52 . The ramp 52 tapers away from the free end 46 such that the ramps 52 has its smallest thickness at the free end 46 .
The linkage 42 is defined by a rod member with the latch 40 at one end and the handle 44 at the other. The linkage 42 extends through the base housing to position the latch 40 on top of the upper portion 28 and the handle on the bottom of the lower portion 32 Thus, as the handle 44 is rotated, the rod linkage 42 directly rotates the latch 40 . The rotation of the handle 44 moves the latch 40 between an open or unlocked position to a closed or locked position as illustrated in FIGS. 2 and 3 .
The cover 12 includes a projecting post member 60 . The post member includes a head 62 extending from the post 60 . The head 62 may be fastened with the post 60 or unitarily formed with it. The head 62 includes a planar surface 64 to contact the ramp 52 .
The latch 40 includes a stop 70 . The stop 70 is positioned at the end of the tapered ramp 52 . The stop 70 is defined by junction of the ramp surface 52 and end surface 72 . The end surface 72 intersects the ramp surface 52 to form a wedge. The stop 70 , with its wedge shape, has the end surface 72 angled towards or away from the tip 46 of the latch 40 . Thus, the stop 70 has a biting line contact into the planar surface 64 of the head 62 to lock the latch 40 in its retained position as illustrated in FIGS. 2 , 4 , and 6 .
The cover 14 is locked with the base 12 as follows. The locking member 18 is rotated via handle 44 which, in turn, moves the ramps 52 on the free end 46 of the latch 44 into contact with the planar surface 64 of the head 62 . As this occurs, the ramp tapered surface 54 is in contact with the planar surface 64 . As the handle 44 continues to rotate, the ramp surface 54 moves along the planar surface 64 . As this occurs, the cover 12 is pulled downward in response to the tapered thickness of the ramp spaced away from the free end 46 . Also, the wedge shape stop 70 comes into the contact with the planar surface 64 . This biting action of the wedge shape stop 70 maintains the latch 40 on the head 62 while the latch is in contact with the head. Also, a portion of the latch 40 is above the head 62 to retain the head 62 from exiting the latch 40 . As the handle 44 reaches its end of rotation, the cover 12 is snuggly pulled against the seal 30 on the periphery of the upper portion 28 of the base 12 as seen in FIG. 4 .
To unlock the cover 14 , the handle 44 is rotated in the opposite direction. As this occurs, the linkage 42 rotates the latch 40 . The thickest portion of the ramp 52 moves away from the planar surface 64 of the head 62 . This movement continues until the latch free end 46 releases from the planar surface 64 as seen in FIGS. 3 and 5 . Thus, the cover 14 is able to be moved from its closed position to an open position.
A crank (not shown) is rotated which, in turn, causes the arm 16 to move away from the base 12 . As this occurs, the arm pin slides in the slot 38 in the bracket 32 . This movement raises the cover 14 , as illustrated in phantom in FIG. 1 , to an open position.
To return the cover 14 to its closed position, the crank is rotated in the opposite direction. Thus, the arm 16 pulls the cover 14 down to contact with the base seal 30 . The arm 16 is on one side of the base 12 while the locking mechanism 18 is on the other. Thus, the arm 16 and locking mechanism 18 pull down two sides of the cover 14 to pull the cover 14 against the base 12 . Thus, a two point cover retention is achieved. This maintains the cover 14 snuggly against the base seal.
The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention.
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A vent assembly has a locking mechanism to retain its cover on its base. The locking mechanism includes a latch and linkage coupled with the latch to move the latch between a locked and an unlocked position. A post member extends from the cover to cooperate with the latch such that in a locked condition, the cover is locked with the base in a closed position. When the latch is moved to a second position, the cover is enabled to pivot away from the base to an open position.
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