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BACKGROUND OF THE INVENTION
The present invention relates to a disk control device or a storage device which stores a large amount of information. More particularly the present invention relates to apparatus for use in a disk control device or a storage device that prevents system downtime and a degeneration in the operation of the device due to a failed part in the device or when the device has partially failed. Even more particularly the present invention provides apparatus that allows for high availability or maintainability in a disk control device or a storage device in which failed parts are exchanged without stopping the device.
In large data storage equipment or large storage systems which store customer information, such as an on-line banking system, it is highly desired to have equipment or a system wherein the stored data is continually available and the equipment or system is easily maintainable. In such equipment or system the operation thereof does not degenerate when a failure has occurred in any part of the equipment or failure. Further, in such equipment or system failed parts can be exchanged without stopping operation thereof.
Storage devices using magnetic disk storage units as a storage media have been proposed. Such systems are known as Redundant Arrays of Inexpensive Disks (RAID) systems. Magnetic disk storage units are quite suitable in such an application since they provide large storage capacity for a unit price. Recently a non-stop system has been proposed by adopting a RAID system in which availability and maintainability is provided by exchanging the magnetic disk units.
FIG. 1 is an example of the construction of a conventional large storage system. A disk controller (DKC) 101 is connected to a host processor 102 as an upper unit through channels 110 and 111 . The DKC 101 is also connected to a disk unit (DKU) 103 as an lower unit through drive buses 112 , 113 , 114 and 115 . Various modules described below are connected to common buses bus 0 and bus 1 117 and 118 respectively wired on a platter (PL) which is the wiring base inside the DKC 101 .
Memory modules 119 and 120 are semiconductor memory (CACHE) containing a copy of data stored in DKU 103 , and data which are transferred from the host processor 102 and stored in DKU 103 . The channel adapter modules (CHA) 121 and 122 are connected to the channels 110 and 111 . The CHA 121 and 122 control data transfer between the host processor 102 and the memory modules 119 and 120 . Disk adapter modules (DKA) 123 and 124 are connected to drives 125 to 128 in DKU 103 through the drive paths 112 to 115 . The DKA's 123 and 124 control data transfer between the memory modules 119 and 120 and the drives 125 to 128 . The memory modules 119 and 120 also store control information required for data transfer control which CHA 121 , 122 and DKA 123 , 124 control. The common buses 117 and 118 are used as paths for data transfer and access for control information between CHA 121 , 122 or DKA 123 , 124 and memory modules 119 and 120 , and for communication between CHA 121 , 122 and DKA 123 , 124 .
The common buses 117 and 118 are composed of a plural number of buses which are physically independent from each other, and their transfer modes are selected by a bus command during the transfer. There are a sequential data transfer mode in which buses logically operate as one bus, and a transaction data transfer mode in which each of the buses operates independently. In the DKC 101 all of hardware parts excepting PL 116 are multiplexed, thereby preventing a complete stop in DKC 101 due to a degenerative process resulting from a partial failure. Non-stop exchanging in all of hardware parts excepting PL 1 116 is possible by non-disruptive exchange of each module. However, there are some problems described below when a part of the device has failed.
FIG. 8 illustrates a configuration, similar to that described in Japanese unexamined patent publication 04-276698, of a conventional wiring board, wherein two wiring boards are provided and one of the wiring boards has one of the bus lines and the other of the wiring boards has the other of the bus lines. In FIG. 8, the two wiring boards are shown as being attached back to back and each printed wiring substrate (MP) is shown as being connected to both of the bus lines of the two wiring boards. Although two wiring boards are disclosed as being connected to each other using a printed circuit board, the details of the printed circuit board are not shown.
In a computer system constructed according to that illustrated in JP-4-276698 system downtime due to bus degeneration can be avoided. Such is possible even when the failure is due to the breaking of wires in the PL itself. However, the disadvantage is that the system must be stopped when the failed bus is to be exchanged, because the failed bus is included in the PL. A further, disadvantage is that the performance of the computer system deteriorates due to the limited transfer bus mode in the operation performed by the degenerated bus.
SUMMARY OF THE INVENTION
An object of the present invention is to provide an apparatus which connects the common buses of different platters (PL's) to each other by use of a connector, wherein each PL is divided into two, thereby allowing a failed PL to be exchanged during operation of the other PL.
Another object of the present invention is to provide an apparatus which permits access to common resources across clusters by use of a communication method, wherein a data transfer mode can be selected based on the state of the clusters.
Yet another object of the present invention is to provide apparatus which improves bus performance and allows for non-stop maintenance for common bus failures in a computer system represented by a large storage device.
The present invention provides a disk control device or a storage device having a plurality of clusters interconnected to each other by a common resource. Each cluster includes a plurality of common buses which are connected to a disk controller (DKA), a channel controller (CHA) and a cache (CACHE). The common resource connects each of the common buses to each other between the clusters.
The common resource includes shared memory and cache memory which allows access from other clusters. The common resource provides lock bits in a control table in the shared memory for indicating whether access to resources corresponding to the bits is possible. Also provided is a microprocessor (MP) communication function using interruption signals between microprocessors in each CHA and DKA to effect communication from a module in one cluster to that in another cluster. This function allows for synchronization to be established in bus modes between clusters and to resolve conflicts in accesses to the common resource. Bus transfer performance in the system increases relative a system in which parallel transfer using common buses across plural clusters is conducted.
The structure of the present invention allows for multiple clusters to be connected to each other and can be applied not only to a large storage device adopting RAID technology but also to a device adopting SLED technology.
BRIEF DESCRIPTION OF THE DRAWINGS
The scope of the present invention will be apparent from the following detailed description, when taken in conjunction with the accompanying drawings, and such detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description, in which:
FIG. 1 illustrates a conventional disk controller;
FIG. 2 illustrates the construction of an apparatus having plural clusters connected by a connector according to the present invention;
FIG. 3 illustrates an embodiment of the present invention in which particular resources are locked;
FIG. 4 illustrates another embodiment of the present invention in which particular resources are locked;
FIG. 5 illustrates a work structure of a lock mask of the present invention;
FIG. 6 illustrates the construction of a register which holds parameters for lock control;
FIG. 7 illustrates a flowchart for establishing parameters for lock control and processing an access to a lock address;
FIG. 8 illustrates a conceptual structure of a conventional computer system to which the present invention can be applied;
FIG. 9 illustrates an example of connection between clusters;
FIG. 10 is a table explaining elements and functions of register LOLD/LNEW;
FIG. 11 is a table explaining elements and functions of register LCNTL; and
FIG. 12 is a table explaining an example of mode selecting on a bus failure.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 2 illustrates the construction of an embodiment of the present invention. Only parts which differ from that in FIG. 1 are explained, omitting the parts having the same construction or the same operation.
The device illustrated in FIG. 2 includes a plural number of clusters CL 1 201 and CL 2 202 . FIG. 2 illustrates two (2) clusters. However, these are just shown for illustration purposes. Any number of clusters can be provided. Each cluster preferably includes at least two parallel common buses 211 and 212 for CL 1 201 and common buses 213 and 214 for CL 2 202 . However, each cluster can include only one common bus. The clusters each includes system modules CHA 203 -CHA 204 and DKA 207 and DKA 208 for CL 1 201 and CHA 205 -CHA 206 and DKA 209 and DKA 210 for CL 2 202 . The system modules of CL 1 201 are connected around PL 1 which includes common buses 211 and 216 . The system modules of CL 2 202 are connected around PL 2 which includes common buses 213 and 214 . Each of CHA 203 to DKA 210 contains a microprocessor. Each cluster CL 1 201 and CL 2 202 form a multi-microprocessor controller system around the common buses in the cluster.
A difference between the device illustrated in FIG. 1 and the present invention as illustrated in FIG. 2 is the arrangement of the cache 220 which is a common resource element. The cache 220 is connected across the clusters so as to be accessed from any of the clusters. Connections between clusters are established by connecting between PL 1 and PL 2 using connectors or cables as illustrated in FIG. 9 .
The cache 220 , which is connected to both clusters, includes a memory module, a cache module, etc. such as a shared memory or a cache memory, and is accessible from CHA 203 , 204 , 205 and 206 , and DKA 207 , 208 , 209 and 210 which are modules in the clusters, through common buses Clbus 0 211 , Clbus 1 212 , C 2 bus 0 213 and C 2 bus 1 214 for the clusters. The overall transfer performance of the device is doubled due to a construction in which the cache 220 can be simultaneously accessed from the cluster CL 1 201 and the cluster CL 2 202 . Overall transfer performance can be multiplied by approximately n if the number of clusters is increased to n as illustrated for example in FIG. 8 .
The above-described accesses can be performed independently from the common bus in a transaction transfer mode and also common buses can be operated logically as a bus in a sequential mode transfer. By use of the above-described structure of the present invention, as illustrated in the table shown in FIG. 12, a sequential bus transfer can be accomplished which are not possible in the conventional apparatus. In the system in the present invention, combinations of buses that are independent to each cluster are possible and two or more bus modes are both possible in a cluster. Bus modes can be flexibly modified to adapt to the details of the process. Each bus mode can be operated in the same data transfer mode in each cluster, or inversely established independently in each cluster.
The transfer mode in conventional apparatus can not be modified due to degenerative bus operation when the common bus fails as shown in the table of FIG. 12 . However, in the present invention, although a cluster with a failure degenerates its bus, in a cluster not having the failure either of the transaction transfer mode and the sequential transfer mode can be selected. Thus, a bus transfer mode fitted to the system condition can be flexibly established so as not to deteriorate overall performance when a failure occurs.
The cache 220 FIG. 2 receives addresses, data and commands (address/data/command) from each common bus. An arbitration is performed internally with respect to each received address/command, and the memory is accessed by a read/write operation. In cache 220 , read/write operations to the same address issued from a plural number of buses are executed without any modification. In the case that write instructions are issued simultaneously from cluster CL 1 201 and the cluster CL 2 202 to the same address (i.e. in the case of conflict in the buses), data to be written to the memory are written exclusively among microprocessors accessing from the cluster CL 1 201 and the cluster CL 2 202 . The conflict is resolved, for example, by memory lock control. An embodiment where resources lock control is performed with respect to the cluster to be accessed by the cache 220 is illustrated in FIG. 3 . Another embodiment where the function of resource lock control is performed with respect to the cluster which requests access is illustrated in FIG. 4 . This function of resource lock control can be provided in each of the modules CHA 203 to DKA 210 .
Embodiment 1 to Solve Conflict (the Common Resource Side)
In FIG. 3, DKA 301 having a microprocessor MP- 1 A and CHA 302 having a microprocessor MP- 2 A are connected to the common buses Clbus 0 305 and Clbus 1 306 in the same cluster. And DKA 303 having a microprocessor MP- 1 Z and CHA 304 having a microprocessor MP- 2 Z are also connected to the common buses C 2 bus 0 307 and C 2 bus 1 308 in the same cluster. MP- 1 A (DKA 301 ) and MP- 2 A (CHA 302 ) are connected to the common buses 305 - 308 in the two clusters by the shared memory (SM) 309 and a SM control circuit (SM CNTL) 310 of the cache 320 . The SM CNTL 310 includes C 1 M 0 311 , C 1 M 1 312 , C 2 M 0 313 and C 2 M 1 314 which supervise lock mask LKMSK and lock address (LKADR) for each common bus.
Each microprocessor described above inputs a lock address (LKADR) to SM CNTL 310 and gets information of the lock status of a resource by the lock mask (LKMSK). SM CNTL 310 reads the indicated lock address (LKADR), stores data that have been read to a data buffer DT BUF 316 . Queue controller QUE CTL 315 calculates queue information (QUE) using the LKMSK and LKADR. The result of the access to the lock address (lock access) is reported to each microprocessor module through the common buses 305 , 306 , 307 and 308 in each cluster, and each of modules 301 to 304 monitors LKADR and QUE information and accesses to LKADR when its turn comes to the top of the QUE, to determine whether the LKMSK has been released. When an access occurs from the top module of the QUE, the common memory control SM CNTL 310 writes data to LKADR addressed by the SM and renews the LKMSK.
Embodiment 2 to Solve Conflict (Each Microprocessor Module Side)
Next is a description of an embodiment in which a function of solving a conflict is included is included in each of CHAs and DKAs.
In FIG. 4, microprocessor based modules MP- 1 A 403 and MP- 1 Z 404 are connected to the common buses Clbus 0 407 and Clbus 1 408 in the same cluster. Microprocessor based modules MP- 2 A 405 and MP- 2 Z 406 are also connected to the common buses C 2 bus 0 409 and C 2 bus 1 410 in the same cluster. SM 401 is connected to the common buses 407 to 410 in two clusters through SM CNTL 402 . In this embodiment a conflict of the lock access in the shared memory SM is solved by a microprocessor (MP) 412 in each module that calculates the QUE. Namely MP- 1 A 403 supervises the lock mask LKMSK, the lock address LKADR and the QUE, thereby arranging a shared memory port (SM PT) 413 between MP 412 and the buses 407 and 408 in the cluster.
The microprocessor MP 412 writes a lock address LKADR and a lock mask LKMSK to the SM PT 413 and performs a lock access. The SM PT 413 reads the lock address in the SM 401 through SM CNTL 402 . The que is calculated in the SM PT 413 from data in the lock mask and data that was read out, and the result is written to LKADR in SM 401 . Other accesses are rejected in the SM CNTL 402 by a lock command in the SM PT 413 and SM CNTL 402 .
Embodiment for Establishing the Lock Mask and Queue
The above-described embodiments solving conflicts lock mask and a queue. An embodiment of a lock mask and a queue are described below.
FIG. 5 illustrates a word structure of the lock address LKADR holding the lock mask and the queue information as elements. The lock mask LKMSK indicates that the word structure is in a lock state. The MPID indicates identification (ID) own ID value of the locked microprocessor in which the lock bit is ON. When the lock bit is ON, MPID is guaranteed until the lock is released. The waiting queue is information for preventing too long of a suspension of the microprocessor if a busy condition occurs due to a lock state for an extended period of time. A suspension that extends too long indicates that the processor never reaches its turn to perform an access.
Bit allocation of the waiting queue is information to guarantee the order of locks by delaying a lock operation, so that an unnecessary lock operation does not occur at the moment the bit just before it, that has been newly registered at the end of the waiting queue in case of lock busy, has turned OFF. The waiting queue in FIG. 5 has a ring structure for example and supervises the order in making a bit at value 0 as a top of the queue. FIGS. 6, 10 and 11 illustrate examples of establishing a register as a control circuit parameter, and FIG. 7 illustrates a flowchart of the process.
In FIG. 6, the LOLD is a register to store data before renewal of the lock mask loaded from the SM. The LNEW is a register to store renewed data of the lock mask loaded from the SM. The LCNTL includes of a CMP DATA, a CNT MODE and a QUEPOS, and the CMP DATA is comparing data to judge renewal of lock. Namely, it is comparing data to the lock byte (LOCK and MPID) in the lock mask, and the lock state is renewed only when the. lock byte agrees with the CMP DATA.
The CNTMODE establishes the control mode in operation when the resource is locked, and an execution/non-execution of the waiting queue registration is controlled by this mode when the CMP DATA does not agree with the lock byte. The QUEPOS establishes the OFF position of the waiting queue when the queue bit is removed (OFF). An illegal waiting queue bit pattern (pattern with some bits missing, example: “0101” or like that) is detected by reading a new SM data stored in the LNEW register.
The flowchart illustrated in FIG. 7 is described below. After the LADR is established following the LCNTL mentioned above, the LNEW is loaded (steps 700 - 703 ). Then an illegal mode establishment is checked through read-modify-write operation steps (steps 704 and 705 ). The LOLD is loaded (step 706 ) and compared with the LNEW. Thereafter a lock bit is established if necessary, and then a waiting queue is registered after a position of the new queue register bit is calculated (step 707 ).
The present invention has further advantages that buses can be repaired without system downtime for a failure of the common buses. Namely, one cluster contains at least two or more common buses, and if a failure in either of the buses is detected, the system module stops use of the failed bus and makes use of the remaining normal (non-failed) buses.
To repair the failed bus, in the cluster that stops operation due to blocking, and degenerates the operation of the cluster of failed side, the PL containing common buses can be exchanged by removing connecting cables or connectors between clusters. By this, problems of failure and repair in the common buses that was conventionally a problem in the disk control device adopting a common bus architecture, can be solved.
Each microprocessor must have a communication apparatus to detect the failed bus and to control switching of the transfer bus. As a communication apparatus of the microprocessor in each module (DKA/CHA), including intermediate clusters of other systems and those of the system itself, a function of referring to the table of system supervising information on the shared memory through the common buses, or a function of a simultaneous (broadcasting) through an interruption signal (hot-line) that is directly connected to each microprocessor may be used. This hot-line can be provided on the common buses, and can select all IDs for each MPID in each microprocessor, specified MPID, or a MPID of one to one.
In the procedure of FIG. 5, a lock bit control of the shared memory is made by verifying the QUE by polling the access timing. If this verification places pressure on real data transfer, the real data transfer can be performed flexibility just after completion of transfer by a method that informs the removal of a lock to a specified group of MPs by combining MP interrupting communications such as a broadcast, or by processing with synchronizing among the MPs. However, it is required to introduce a micro-program control to prevent suspension that may be too long.
The clustered bus structure of the present invention provides a device in which bus transfer performance is improved, and in which correction of degeneration and repair operations resulting from a failure in the platter having common buses are possible. Further the modes of use of the buses (bus mode) can be flexibly modified to fit the particular failure encountered. Still further, common system modules such as memory can be accessed from each cluster and across clusters making possible communications between modules across clusters. Possible conflicts of access from the common buses in each cluster are solved by a resource lock control.
Thus, the system in the present invention is equipped with a plural number of clusters which includes control basic units that are connected around duplicated or multiplied common buses, for example, channel controllers or disk controllers, and is equipped with resources and a communication system common to each cluster. This structure of the present invention improves transfer performance of each common bus. Further, in the present invention it is possible to repair a failed part, especially a platter while keeping the system in operation. In the present invention even if a failure in a cluster occurs, it is possible to switch the mode of the common buses in the other clusters to accommodate the failure.
While the present invention has been described in detail and pictorially in the accompanying drawings, it is not limited to such details since many changes and modification recognizable to these of ordinary skill in the art may be made to the invention without departing from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.
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An apparatus for use in a storage device having at least two clusters, each including a disk control device having a plurality of channel controllers that send and receive commands and data to and from an upper system, a plurality of disk controllers that control disk units, and a cache that temporarily stores data between the upper system and the disk units. The apparatus includes a first bus included in a first cluster. The first bus is connected to the channel controller, the disk controller and the cache of the first cluster. A second bus is included in a second cluster. The second bus is connected to the channel controller, the disk controller and the cache of the second cluster. A common resource is connected to the first bus of the first cluster and the second bus of the second cluster. The common resource includes a specified set of data which is commonly accessible from each of the channel controllers or the disk controllers of the clusters.
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BACKGROUND OF THE INVENTION
The present invention relates to an image reading device that reads information of an image photographed on a 35 mm standard negative film, and more particularly relates to an image reading device that reads information of an image photographed on a pseudo panoramic negative film.
Recently, pseudo panoramic photographing has been conducted on a 35 mm standard negative film, or both standard photographing and pseudo panoramic photographing have been conducted with a 35 mm standard negative film. Images on a negative film obtained by the pseudo panoramic photographing are printed, and also images on a standard negative film obtained by both the standard photographing and the pseudo panoramic photographing are printed. When images obtained by the pseudo panoramic photographing are printed, it is necessary to cover the portions of the film on which the pseudo panoramic photographing has not been conducted.
In order to cover the non-image portions of the film on which the pseudo panoramic photographing has not been conducted, it is necessary to read the pseudo panoramic photographed images on the film. However, the aforementioned type image reading device has not been provided yet. For example, the following image reading method can be easily devised. In the method, the same panoramic adapter as that used for pseudo panoramic photographing is used so as to cover the non-image portions of the film on which the pseudo panoramic photographing has not been conducted.
However, the standard of panoramic adapters has not been standardized yet, so that the dimensions and position of a panoramic adapter depend on the camera manufacturers. Even when the same panoramic adapter is used for the same camera, there is a possibility that the position of an image photographed on a film is shifted due to the influence of the optical system and the shift of the film. Therefore, it is difficult to completely remove the non-image portion by using a panoramic adapter.
In the case where an image on a pseudo panoramic photographed image is read while the pseudo panoramic photographing negative film is set on a 35 mm conventional standard mount, even the unexposed non-image portion is subjected to image reading processing, so that the read portion is outputted into black. Therefore, when the image is reproduced by a copier, black toner is wasted.
Even if the panoramic adapter is standardized, in the case where both pseudo panoramic images and standard images are photographed on the same film, the following troublesome operations are required for an operator: in the case of a pseudo panoramic image, the panoramic adapter is inserted, and in the case of a standard image the panoramic adapter is removed.
The present invention has been achieved to solve the aforementioned problems. The first object of the present invention is to provide an image reading device capable of removing unnecessary portions except for a portion in which the pseudo panoramic photographing has been conducted, without using a panoramic adapter.
In the case where printing is carried out using a pseudo panoramic photographing negative film, image information of the pseudo panoramic photographing negative film is read by an image reading device, and the obtained image information is subjected to image processing, and then the image information is outputted to a copier. Before the aforementioned image processing, shading correction is carried out. This shading correction is carried out in the following manner: a frame of the unexposed portion of the film or a corresponding filter is set in a film holder; and the film holder is inserted into a projector so that shading correction is conducted in accordance with the information of the unexposed portion.
According to the aforementioned method, it is necessary to prepare an unexposed frame, the type of which is the same as that of the photographed negative film. Therefore, the aforementioned method is not practical.
However, unexposed frames tend to fade when they are preserved, and further they are susceptible to damage. Therefore, when a shading operation is conducted with a faded unexposed film, the colors of the photographed negative film and those of the unexposed frame can not be balanced, so that color reproduction can not be accurately carried out.
Pseudo panoramic photographing negative film has come into wide use recently. However, image information is read and outputted by the same procedure as that of a conventional standard photographing negative film. For example, in the case where exposure control data is taken in, there is no control method suitable for a pseudo panoramic photographing negative film, so that the conventional exposure control method has been used for the pseudo panoramic photographing negative film until now.
The same method as that of a standard photographing negative film is applied to a pseudo panoramic photographing film. Therefore, although a non-image portion exists on the film, a frame of another unexposed negative film is used separately from the photographed film. Further, it is necessary to previously conduct a shading operation in addition to a reading operation.
In addition, when the exposure control data is taken in, almost all the image portions of the standard photographing film are used as data in order to improve the accuracy. In the case of a pseudo panoramic photographing negative film, the image portion is located only in the center of the frame. Therefore, the same image range as that of the standard negative film is taken in for the pseudo panoramic photographing negative film. For that reason, the density of the exposure control data becomes lower than that of an actual image. After all, it is judged that the density of the pseudo panoramic photographing negative film is lower than that of an actual image, so that the exposure amount for the pseudo panoramic photographing negative film is reduced. As a result, the obtained film is finished under exposure.
The present invention has been achieved to solve the aforementioned conventional problems. The second object of the present invention is to provide an image reading device by which excellent finished images can be obtain from a pseudo panoramic photographing negative film.
The conventional image information reading of a pseudo panoramic photographing negative film is carried out as follows: a shading operation is conducted before image processing; exposure control is conducted; and then a reading operation is conducted. Therefore, the image reading process is complicated and troublesome.
In the case where image information of a pseudo panoramic photographing negative film is read a plurality of times, the shading data is collected at each time, or the shading data is collected for the first time, and the same data is used after that. It is complicated to conduct the shading operation at each time as described above, and when the shading operation is conducted only once, it is impossible to maintain the image quality.
In view of the aforementioned point, it is an object of the present invention to provide an image forming device by which image information can be easily read from a pseudo panoramic photographing negative film.
The third object of present invention is to provide an image forming apparatus by which a predetermined image quality level can be maintained when a minimum shading correcting operation is conducted.
Problems will be described as follows that are caused when the aforementioned conventional image reading device is applied to a copier.
In order to directly print an image onto a photographic paper from a negative film, a high level of technique and special apparatus are required. Therefore, it is difficult for amateurs to print easily.
On the other hand, technique of a color copier has made a great advance recently, so that a color image recorded on a paper can be highly accurately copied.
As a result of the foregoing, the following color-copier has been proposed recently (for example, Japanese Patent Application Open to Public Inspection No. 46646/1991): An image recorded on a film of various kinds is projected by a projector. The projected image is photoelectrically read by an image reading device provided with a photoelectric transfer element such as a CCD sensor in a color copier so that an electrical image signal is obtained. In accordance with the obtained electrical image signal, a color-copying operation is carried out.
When an image recorded on a film is projected by a projector, the operations are carried out in the following manner: the film is mounted on the projector with a film carrier; the film is .irradiated with light; the optical path of the transmission light is changed by a mirror unit; the film image is projected onto a Fresnel lens on the platen of the color copier; and the film image projected on the Fresnel lens is electrically read by an electrophotographic transfer element such as a CCD sensor of the color copier. The copy paper is selected and printing magnification is determined in accordance with the image that has been read in the aforementioned process.
An object of the conventional image reading device used for the aforementioned projector is designed to project an image recorded on a 35 mm film that is the most popular among amateurs.
As shown in FIG. 1, the aforementioned pseudo panoramic film to record a panoramic image on a 35 mm film is used in the following manner: the upper and lower portions of an ordinary frame, the size of which is 24 mm×36 mm, are shaded so that a horizontal image screen size (13 mm×36 mm) can be obtained.
As described above, the size of a projected image on a pseudo panoramic film is extremely long from side to side, that is the length of a longitudinal side is very different from that of a lateral side compared with a standard 35 mm film. Therefore, the fourth object of the present invention is to provide appropriately determine the paper size, printing magnification and printing position in accordance with a projected panoramic image.
SUMMARY OF THE INVENTION
In order to accomplish the aforementioned first object, the present invention is to provide an image reading device, comprising: an image reading means to read image information on a standard photographing negative film and a pseudo panoramic photographing negative film; and a removing means to remove an unnecessary portion from the image information sent from said image reading means, said unnecessary portion being defined as a portion except for a pseudo panoramic photographed portion .
The image reading device of the present invention comprises: an image reading means to read image information of a standard photographic image and a pseudo panoramic photographic image, both said standard photographic image and said pseudo panoramic photographic image existing on a negative film; a discriminating means to discriminate between standard photographing and pseudo panoramic photographing from the image information sent from the image reading means; and a removing means to remove an unnecessary portion from the discrimination results obtained by said discriminating means, said unnecessary portion being defined as a portion except for a pseudo panoramic photographed portion.
In the image reading device of the present invention, said removing means is characterized in that: the unnecessary portion except for a pseudo panoramic photographed portion is removed by region discrimination; and in the case where the region discrimination can not be carried out, the unnecessary portion except for a pseudo panoramic photographed portion is removed using a predetermined region.
In the present invention, image information of a standard photographing negative film and a pseudo panoramic photographing film is read, and an unnecessary portion except for a pseudo panoramic photographed portion is removed from this image information.
According to the present invention, image information of a standard photographing negative film and a pseudo panoramic photographing film is read, both said standard photographing negative film and said pseudo panoramic photographing film existing on the same negative film; standard photographing and pseudo panoramic photographing are discriminated from said image information; and an unnecessary portion except for the pseudo panoramic photographed portion is removed from the discrimination result.
According to the present invention, the unnecessary portion except for a pseudo panoramic photographed portion is removed by region discrimination, and in the case where the region discrimination can not be carried out, the unnecessary portion except for a pseudo panoramic photographed portion is removed using a predetermined region.
In order to accomplish the second object, the present invention is to provide an image reading device that reads and processes image information of a pseudo panoramic photographing negative film photographed using a standard negative film, comprising a shading correction means that conducts shading correction using a non-image portion except for the aforementioned pseudo panoramic photographed portion.
The present invention is to provide an image reading device that reads and processes image information of a pseudo panoramic photographing negative film photographed using a standard negative film, comprising an exposure control means to control exposure Using only the image portion photographed on said pseudo panoramic photographing film as exposure control data.
The present invention is to provide an image reading device that reads and processes image information of a pseudo panoramic photographing negative film photographed using a standard negative film, comprising a means to take shading correction data and exposure control data during prescanning before the image information of said pseudo panoramic photographing negative film is read.
In the case where image information of a pseudo panoramic photographing negative film is read and processed, shading correction is conducted using a non-image portion except for a portion photographed on a pseudo panoramic photographing negative film. As described above, it is not necessary to prepare a surplus frame on the unexposed film for shading, and shading can be carried out in the same frame of the photographed pseudo panoramic photographing negative film. Therefore, the photographic conditions are the same, so that color reproduction is very accurate in the developing process. Also, the shading correction is carried out in the same frame on the pseudo panoramic photographing negative film, the film preserving conditions are precisely the same. Accordingly, an accurate shading correction can be carried out compared with a case in which shading is carried out using an unexposed film.
In the case where image information of a pseudo panoramic photographing negative film is read and processed, the image portion photographed on the pseudo panoramic photographing negative film is used as exposure control data, and exposure is controlled. As described above, exposure control data is read from an image portion except for the non-image portion of the photographed pseudo panoramic photographing negative film. Therefore, exposure control is accurately conducted, and further a reversal operation from negative to positive can be precisely carried out.
In the case where the image information of a pseudo panoramic photographing negative film is subjected to image reading processing, shading correction data and exposure control data are taken in a prescanning process conducted before the image information of-the pseudo panoramic photographing negative film is subjected to image reading processing. Since the shading correction is conducted in one prescanning operation as described above, it is not necessary to conduct the shading correction independently. Therefore, the operator can read image data without giving consideration to the shading correction. Further, only the image portion in which exposure control data has been photographed, is read, so that exposure control can be accurately carried out, and furthermore negative-positive--reversal can be accurately carried out.
In order to accomplish the third object of the present invention, the image reading device of the invention in which image information on a pseudo panoramic photographing negative film photographed with a standard negative film is read and processed, comprises a means that conducts shading correction in the non-image portion on said pseudo panoramic photographing negative film, and then reads the image portion as it is.
The image reading device of the invention in which image information on a pseudo panoramic photographing negative film photographed with a standard negative film is read and processed, comprises a means characterized in that: in the case where said pseudo panoramic photographing negative film photographed is read a plurality of times, the reading operations of the second time and after that are conducted using the shading data of the first time.
The image reading device of the invention in which image information on a pseudo panoramic photographing negative film photographed with a standard negative film is read and processed, comprises a means characterized in that: when the same frame on said pseudo panoramic photographing negative film is read a plurality of times, the reading operations of the second time and after that are conducted using the shading data or exposure control data of the first time, or the reading operation after the second time is conducted using the shading data and exposure control data.
The image reading device of the invention in which image information on a pseudo panoramic photographing negative film photographed with a standard negative film is read and processed, comprises a means that collects the shading data once in a plurality of times in the case where said pseudo panoramic photographing negative film is read a plurality of times.
After shading correction has been conducted in the non-image portion of the pseudo panoramic photographing negative film, the image portion is read as it is. For example, in the case where the exposure conditions have already been known, it is not necessary to conduct exposure control, and shading and reading are conducted by one scanning operation.
In the case where the pseudo panoramic photographing negative film is read a plurality of times, the reading operations of the second time and after that are conducted using the shading data of the first time, so that the number of the shading operations that have been conducted a plurality of times can be reduced to one. Therefore, the reading operation can be simplified.
In the case where the same frame of the pseudo panoramic photographing negative film is read a plurality of times, the reading operations of the second time and after that are conducted using the shading data or exposure control data of the first time, or using the shading data and exposure control data. Since the same frame is read, the shading and exposing conditions are not changed. Therefore, the reading operations of the second time and after that can be simplified when the data of the first time is used.
When the pseudo panoramic-photographing film is read a plurality of times, the shading data is collected once in a plurality of times so that a minimum times of correcting operations are conducted in order to maintain a predetermined quality level.
The image reading device of the invention to accomplish the fourth object comprises: a detection means to detect an inserting direction of a film carrier used for inserting a film, on which a panoramic image is recorded, into the projector; and a paper determining means to determine a paper, on which the panoramic image is to be printed, in accordance with the film carrier inserting direction detected by said detection means.
The aforementioned image reading means comprises a print magnification determining means that determines the magnification of a printed image in accordance with the longitudinal length of the panoramic image projected by the projector, and also in accordance with the length of the side of a printing paper that is located in parallel with the longitudinal direction of the printed panoramic image.
The aforementioned image reading device comprises a print position control means that controls a print position of the panoramic image on the paper.
The aforementioned print position control means includes: a calculation means to calculate the number of panoramic images that can be printed on the paper in accordance with the size of the paper; and a print position designating means to designate the print position on the paper in the case where the number of images calculated by the calculation means is plural.
According to the aforementioned structure of the invention, for example, papers of A4 size are prepared, in the case where the inserting direction is in parallel with the longitudinal direction of the panoramic image, A4 papers, the lateral side of which-is longer that the longitudinal side, are selected, and in the case where the inserting direction is in parallel with the lateral direction of the panoramic image, A4R papers, the longitudinal side of which is longer than the lateral side, are selected, so that the direction of papers is matched to the direction of the panoramic image.
Compared with a print paper, the lateral length of a panoramic image is extremely longer than the longitudinal length. Therefore, the panoramic image can be positively printed on a print paper, and also the panoramic image can be printed in a desired position on the printer paper.
In the case where a plurality of panoramic images are printed on a print paper, they can be printed so that any empty portion can not be made on the paper. Therefore, the print papers are not wasted.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic illustration showing the structure of the image reading device described in claim 1;
FIG. 2 is a schematic illustration showing the structure of the image reading device described in claim 2;
FIG. 3 is a schematic illustration showing the structure of an image reading device to which the present invention is applied;
FIG. 4 is a fundamental flow chart showing the operation of film reading;
FIG. 5 is a schematic illustration showing the circuit of an image reading device;
FIG. 6 is a graph showing a relation between the exposure amount and the density in the case of green of a color negative film, wherein the exposure amount is represented by logarithm;
FIG. 7 is a flow chart that discriminates between an image portion and a non-image portion;
FIG. 8 is a graph showing an outputting condition in the primary scanning direction of a line sensor;
FIG. 9 is a graph showing an outputting condition in the primary scanning direction of a line sensor;
FIG. 10 is a graph showing an outputting condition in the primary scanning direction of a binarized line sensor;
FIG. 11 is a graph showing an outputting condition in the primary scanning direction of a binarized line sensor;
FIG. 12 is a circuit diagram of an image reading device;
FIG. 13 is a view showing projected images of standard photographing and pseudo panoramic photographing;
FIG. 14 is a view showing one frame of lateral type pseudo panoramic negative film;
FIG. 15 is a graph showing an outputting condition in the primary scanning direction of the line sensor in the non-image portion of a lateral type pseudo panoramic negative film;
FIG. 16 is a graph showing an outputting condition in the primary scanning direction of the line sensor in the image portion of a lateral type pseudo panoramic negative film;
FIG. 17 is a graph showing an outputting condition that has been binarized in the primary scanning direction of the non-image portion;
FIG. 18 is a graph showing an outputting condition that has been binarized in the primary scanning direction of the image portion;
FIG. 19 is a view showing one frame of a longitudinal type pseudo panoramic negative film;
FIG. 20 is a graph showing an outputting condition in the primary scanning direction of the line sensor of longitudinal type pseudo panoramic negative film;
FIG. 21 is a graph showing an outputting condition in the primary scanning direction of a binarized line sensor;
FIG. 22 is a view showing an outputting condition of D-type flip flop 42;
FIG. 23 is a view showing an outputting condition of D-type flip flop 41;
FIG. 24 is a view showing a binarized outputting condition in the primary scanning direction of the non-image portion of a lateral type pseudo panoramic negative film;
FIG. 25 is a view showing a binarized outputting condition in the primary scanning direction of the image portion of a lateral type standard negative film;
FIG. 26 is a view showing a binarized outputting condition in the primary scanning direction of the image portion of a longitudinal type pseudo panoramic negative film;
FIG. 27 is a view showing a binarized outputting condition in the primary scanning direction of the image portion of a longitudinal type standard negative film;
FIG. 28 is a perspective view of a film carrier for negative film use;
FIG. 29 is a view showing an example of the image processing circuit diagram of the color image reading device to accomplish the second object of the invention;
FIG. 30 is a flow chart showing a control procedure;
FIG. 31 is a view showing the circumstances of taking shading data of a standard photographing negative film;
FIG. 32 is a view showing the circumstances of taking exposure control data of a standard photographing negative film;
FIG. 33 is a view showing the circumstances of taking shading data of a pseudo panoramic photographing negative film;
FIG. 34 is a view showing the circumstances of taking exposure control data of a pseudo panoramic photographing negative film;
FIG. 35 is a flow chart showing a control procedure to accomplish the third object of the present invention;
FIG. 36 is a flow chart in the case where shading data is collected once in a plurality of times when a pseudo panoramic photographing negative film is read a plurality of times;
FIG. 37 is a schematic illustration showing showing an example of the image reading device relating to the present invention;
FIGS. 38a and 38b are views showing a relation between the film carrier inserting direction and the predetermined paper in this example;
FIG. 39 is a schematic illustration for explaining a centering mode to designate a print position of this example; and
FIG. 40 is a schematic illustration for explaining a frame designating mode in the print position designation of this example.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
A specific example of the present invention will be explained as follows with reference to the attached drawings.
FIG. 1 is a schematic illustration of the image reading device of the present invention. This image reading device includes: an image reading means 500 that reads image information of standard photographing negative film F1 and pseudo panoramic photographing negative film F2; and a removing means 501 that removes unnecessary portion F2a of pseudo panoramic photographing negative film F2 according to the image information sent from the image reading means 500, wherein unnecessary portion F2a is a portion on pseudo panoramic photographic negative film F2 in which any images are not photographed. This removing means 501 discriminates unnecessary portion F2a of pseudo panoramic photographing negative film F2 by means of region discrimination and removes it. In the case where this region discrimination can not be carried out, unnecessary portion F2a on pseudo panoramic photographing negative film F2 in which no images are photographed, is removed using a predetermined region.
Since unnecessary portion F2a can be removed from pseudo panoramic photographing negative film F2, both standard photographing negative film F1 and pseudo panoramic photographing negative film F2 can be read using a standard photographing negative film carrier. When an image on this pseudo panoramic photographing negative film F2 is read in the same manner as that of an image on standard photographing negative film F1, a user can read negative film images without giving consideration to the photographing condition such as a pseudo panoramic photographing condition or a standard photographing condition.
FIG. 2 is a schematic illustration showing the structure of the image reading device of the present invention. This image reading device includes: an image reading means 600 that reads the image information of standard photographing F3a photographed on standard negative film F3 and also reads the image information of pseudo panoramic photographing F3b ; a discrimination means 601 that discriminates between the standard photographing and the pseudo panoramic photographing according to the image information sent from the image reading means 600; and a removing means 602 that removes unnecessary portion F3c except for a portion in which a pseudo panoramic image is photographed. This removing means 602 removes the unnecessary portion F3c in which a pseudo panoramic image is not photographed, by means of region discrimination. In the case where this region discrimination can not be carried out, unnecessary portion F3c on pseudo panoramic photographing negative film in which no images are photographed, is removed using a predetermined region.
As described above, unnecessary portion F3c can be removed that is except for a portion on which panoramic photographing has been conducted. Therefore, only when standard negative film F3 on which both standard photographing portion F3a and pseudo panoramic photographing portion F3b are provided, is set on a negative film carrier for standard photographing, photographing portion F3a and pseudo panoramic photographing portion F3b can be read. Accordingly, a user can read negative film images without giving consideration to the photographing condition such as a pseudo panoramic photographing F3b condition or a standard photographing F3a condition.
Next, a more specific example of this image reading device will be explained as follows.
1. Outline of the Image Reading Device
FIG. 3 is a schematic illustration showing the structure of the image reading device to which the present invention is applied. As shown in FIG. 3, the image reading device includes a film projector 200, a mirror unit 300 and an image reading section 400 of a digital color copier. In this image reading device, a document image is read in such a manner that a ray of light is transmitted through the document.
Structure of the Film Projector 200
This film projector 200 includes grooves 203 provided on the upper and side surfaces of the film projector body 201 so that a film carrier 202 supporting document film F can be longitudinally or laterally inserted into the projector body 201. For this film carrier 202, both a carrier for 35 mm negative film use and-a carrier for reversal film use are prepared. Therefore, these films can be provided to the film projector body 201 through the aforementioned carriers.
In the film projector body 201, a light source lamp composed of a reflector 210 and a halogen lamp 211 is disposed coaxially with a projection lens 212. A cooling fan 213 to cool the halogen lamp 211 is provided close to the halogen lamp 211. Further, on the left of the halogen lamp 211, a condenser lens 214 to converge a ray of light sent from the halogen lamp 211, a convex lens 215 and a heat absorbing filter 216 to cut a ray of light of a predetermined wavelength, are respectively disposed coaxially with the projection lens 212.
A correction filter 217 to correct the spectral characteristics of a film and also to correct the spectral characteristics of the lamp is provided on the left of the heat absorbing filter 216, and also a diffusion plate 218 to hide the filament of the light source lamp is provided.
The electrical power source of this film projector 200 is provided separately from that of the base machine 700.
Structure of the Mirror Unit 300
In the mirror unit 300, total reflection mirror 301 is supported by the film projector body 201 so that an angle formed by the all reflection mirror 301 and the bottom portion 302 can be 45°. An opening 303 is formed in the bottom portion 302, and a Fresnel lens 304 is provided in the opening 303. The Fresnel lens 304 changes the ray of light reflected by the total reflection mirror 301, which is going to diffuse, into a parallel ray of light, so that the spherical portion of the image can be brightened.
In the case where a color copying operation is not carried out, the mirror unit 300 is accommodated in the film projector body 201. Then, the mirror unit 300 is placed in a predetermined position on a platen glass 701 of the base machine to be used.
Structure of the image reading section 400
The image reading section 400 includes mirrors 411, 412, 413, condenser lens 410, CCD 420 that is a photoelectric conversion element, image reading section 430 and image processing section 440. A reading operation is carried out according to the following reading mode.
Reading Mode
The reading mode comprises two modes, one is a negative film mode, and the other is a reversal film mode. These mode can be selected by a selection key (not shown) provided on the image reading device body.
Flow of Reading Operations
FIG. 4 is a flow chart of fundamental film reading operations. First, a film is set on the carrier (step a). This carrier is set at the projector (step b), and it is judged whether the carrier is set longitudinally or laterally (step c). In step d, it is judged whether the film is a negative film or a reversal one. In the case of a negative film, a shading operation is conducted on the film base (step e). In the case of a reversal film, a shading operation is conducted without the film base (step i). Then, the copy button is pressed (step f), and a prescanning operation is carried out so that region discrimination is conducted on the image on the negative film and image information is read (step g). Then, the scanning operations of red (R), green (G) and blue (B) are carried out. In the manner described above, the image photographed on the negative film can be read.
II Method for Determining an Effective Image Region of Pseudo Panoramic Film
II-0 Structure of the Entire Image Reading Device
FIG. 5 is a schematic illustration showing the structure of the image reading device. As shown in FIG. 5, an image signal is read by the CCD 420 of the photoelectric conversion element of the line sensor. The read image signal is amplified by the amplifier 431, and the amplified image signal is converted into a digital signal by the A/D converter 432. This digital signal is corrected by the shading correcting section 433 and stored in the line memory 435 controlled by the CPU 434. According to the image signal that has been corrected by the shading correcting section 433, pixel discrimination is conducted in the region discriminating section 436 in order to discriminate whether it is an image portion or a non-image portion. In this way, the effective image region is determined. The effective image region signal of the region discriminating section 436 is sent to the image processing section 440 through the I/O circuit 437. Not only the effective image region signal of the region discriminating section 436 but also an image signal of the shading correcting section 433 is sent to this image processing section 440 so that both signals are processed.
II-I Pixel Discrimination
(Discrimination between an image portion and a non-image portion)
FIG. 6 is a graph showing a relation between the exposure amount and the density in the case of green of a color negative film, wherein the exposure amount is represented by logarithm. In FIG. 6, character A represents a range of density in which a photographed image is substantially recorded on a film. The minimum density in FIG. 6 is the fogging density (Base 1) of the film base. As shown in FIG. 6, a difference is made between the minimum density (Base 1) and the minimum density (Base 2) of the density range A recorded on the film. When a threshold value is set in this difference, the image and non-image portions can be discriminated and separated, and the data can be binarized.
From the viewpoint of the aforementioned concept, the image and non-image portions are discriminated in accordance with the flow chart shown in FIG. 7. Next, the flow shown in FIG. 7 will be explained as follows. Shading correction is conducted on the film base that is an unexposed portion (step a). The shading correction is conducted here for the purpose of correcting nonuniformity of the irradiating light distribution in the projecting optical system, and also for the purpose of correcting the fluctuation of sensitivity of the photoelectric conversion element of the line sensor. In addition, the shading correction is conducted here for the purpose of setting the reference level of the film base. However, in the case where the signal is read on the film base under the aforementioned condition, the result is not good as shown in FIG. 8. Therefore, the comparative voltage in the A/D-converter is slightly lowered (step b). As shown in FIG. 9, the output of the film base is made to be 225 (the maximum value of the quantization level) wherever possible, so that the separation accuracy to separate the image portion from the non-image portion can be improved.
For example, when threshold value TH is set at 250, the image signal that has been read by the CCD of the photoelectric conversion element of the line sensor, is binarized at each pixel in the following manner: values not less than 250 are defined as 1 (non-image portion), and values smaller than 250 are-defined as 0 (image portion) (step c). For example, an image illustrated in FIG. 10 is discriminated, and the image and non-image portions are separated from each other at each pixel as shown in FIG. 11.
Next, with reference to the circuit diagram of the image reading device shown in FIG. 12, a substantial signal flow will be explained as follows. Information is transmitted and received between the CPU 20 and the memory 21 of the image forming device through the data bus 132 and the address bus 133. Information is transmitted and received between the CPU 20 and the interface 19 through the data bus 130 and the address bus 131. The output 125 of the lateral film carrier judging switch 16 is inputted into this interface 19. The output 126 of the longitudinal film carrier judging switch 17 is also inputted into the interface 19. The CPU 20 controls the flow of the circuit in accordance with the judging switch output 125 and the judging switch output 126.
The auxiliary scanning image region tip signal 129 is inputted from the interface 19 into the signal processing timing circuit 18. The CCD drive pulse 127 is outputted from the signal processing timing circuit 18 into the CCD 1, and the A/D converter conversion clock 128 is outputted into the A/D converter 3. The primary scanning image effective signal 109 is outputted from this signal processing timing circuit 18 to the image discrimination counter 7, the image address counter 8 and the line counter 9. Also, the image signal clock 110 is outputted into the image address counter 8 and the AND circuit 32, and further the auxiliary scanning image effective signal 111 is outputted into the line counter 9.
Accordingly, the negative film image is converted into a reading image signal by the CCD 1, and amplified by the amplifier 2 so that the signal is converted into the analog image signal 101. While this converted analog image signal 101 refers to the A/D converter full scale voltage 102 sent from the switches 4, the converted analog image signal 101 is converted into the digital image signal 104 by the A/D converter 3. Concerning the A/D converter full scale voltage 102 sent from the switches 4, V1 is selected by the A/D converter full scale voltage selection signal 103 controlled by the CPU 20 in the case of shading data collection and normal image reading. In the case where the image and non-image portions are discriminated in the image region discrimination, V2 that is slightly lower than V1 is selected by the A/D converter full scale voltage selection signal controlled by the CPU 20. When V2 is selected, the accuracy of discrimination between the image and non-image portions can be improved.
Then, the digital image signal 104 passes through the shading correcting section 30, and corrects the nonuniformity of the distribution of irradiating light and also corrects the fluctuation of sensitivity of the CCD of the electrophotographic conversion element of the line sensor. After the shading correction conducted in the shading correcting section 30, the digital image signal 104 is sent to the comparator 5. Then, the digital image signal 104 is compared with the image/non-image portion discriminating signal 105 sent from the CPU 20, for example, the digital image signal 104 is compared with the signal level valve 250, and the values of the image signal not less than 250 are defined as 1, and the values of the image signal smaller than 250 are defined as 0 so as to be binarized. Therefore, the image portion becomes 0, and the non-image portion becomes 1. In the manner described above, the image and non-image portions are discriminated.
II-3 Method for Determining an Effective Image Region
Next, an image region described as follows is determined to be an effective image region: it is an image region that , has been photographed in accordance with the data discriminated between the image and non-image portions at each pixel in the pixel discrimination described in item II-1 (it is a discriminating operation to discriminate between the image and non-image portions).
Negative films are photographed under the condition that they are placed longitudinally, and alternatively, negative films are photographed under the condition that they are placed laterally. Therefore, the structure of an image photographed on a negative film is different according to "longitudinal X" and "lateral Y" as shown in FIG. 13. Therefore, whether the film carrier is set longitudinally or laterally is Judged by a sensor of the projector, and the processing of an effective image region is varied according to "longitudinal X" and "lateral Y".
II-3-1 Lateral Type
One frame of a lateral type pseudo panoramic negative film is shown in FIG. 14. The hatched portion of this pseudo panoramic negative film is an image portion G1, and a portion except for the hatched portion is a non-image portion G2. FIG. 15 shows a profile in the primary scanning direction of non-image portion G2 of portion A in FIG. 14. FIG. 16 shows a profile in the primary scanning direction of image portion G1 of portion B in FIG. 14. These are binarized using a predetermined threshold Valve TH in the same manner as conducted in the pixel discrimination of item II-1. FIG. 17 shows the result in the case of the primary scanning direction of non-image portion G2 of portion A in FIG. 14. FIG. 18 shows the result in the case of the primary scanning direction of image portion G1 of portion B in FIG. 14. In the image data of one primary scanning line on the non-image portion, the number of pixels whose output level is 1 is N, which is the number of pixels of one primary scanning line. On the other hand, the number of pixels is approximately 0 in the image portion. Using the aforementioned relation, the effective image region in one frame of a lateral type pseudo panoramic negative film is determined.
Next, with reference to FIG. 12 that is a circuit diagram of an image reading device, a substantial signal flow will be explained as follows.
According to the signal 134 from the CPU 20 to determine the lateral starting-position or the lateral end position, the signal 106 representing the discrimination result between the image portion (0) and non-image portion (1) that are pixel-discriminated in the aforementioned item II-1, is selected by the switches 6 between the following two cases: one is a case in which the signal 106 of the discrimination result between the image portion (0) and the non-image portion (1) is taken; and the other is a case in which the reversal signal 107 obtained when the signal 106 is inverted by the inverter 31, is taken.
First, the starting position of the effective image region is determined. According to the lateral starting position signal 134 sent from the CPU 20, the signal 106 representing the discrimination result between the image portion (0) and the non-image portion (1) is selected by the switches 6. In this case, a signal sent to the image discrimination counter 7 is 0 in the image portion, and 1 in the non-image portion, and the counter clock 108 for counting pixels is counted by the image discrimination counter 7. This image discrimination counter 7 is reset at each line, so that the number of pixels of the non-image portion (1) is counted at each line. The number of lines is counted by the line counter 9 at each line. The comparator 15 compares the image region discriminating threshold value (for example, 0) 123 sent from the CPU 20, through the interface 19, with the output 112 of the pixel number counting value of the non-image portion sent from the image discriminating counter 7, and the film lateral position image region discriminating result 124 is sent to the CPU 20 through the interface 19. The comparator 15 compares the image region discriminating threshold value (for example, 0) 123 with the number obtained by the image discrimination counter 7. The number obtained by the line counter 9 that becomes the image region discriminating threshold value (for example, 0) 123 for the first time, that is, the start line of the effective image region is accommodated in the latch 13, and at the same time the lateral end position signal 134 is sent to the switches 6 from the CPU 20. The.-accommodating operation of the latch 13 is carried out in the following manner: the image portion tip line address value 119 at the film lateral position is held in the memory 21 by the image portion tip line holding signal 117 at the film lateral position sent from the interface 19.
Next, when the lateral end position determining signal 134 is sent to the switches 6 from the CPU 20, the end position of the effective image region is determined. In this case, the reversal signal 107 of the discrimination result signal 106 to discriminate between the image and non-image portions is selected, and the image portion becomes 1 and the non-image portion becomes 0. That is, the image discrimination counter 7 is reset at each line, and the number of pixels of the image portion is counted at each line. In the same manner as the starting position determination, the comparator 15 compares the image region discrimination threshold value (for example, 0) 123 sent from the CPU 20, with the number obtained by the image discrimination counter 7. The number obtained by the line counter 9 that becomes the image region discriminating threshold value (for example, 0) 123 for the first time, that is, the end line of the effective image region is accommodated in the latch 12. The accommodating operation of the latch 12 is carried out in the following manner: the image portion tail line address value 120 at the film lateral position is held in the memory 21 by the image portion tail line holding signal 118 at the film lateral position sent from the interface 19.
II-3-2 Longitudinal Type
One frame of a longitudinal type pseudo panoramic negative film is shown in FIG. 19. The hatched portion of this pseudo panoramic negative film is an image portion G3, and a portion except for the hatched portion is a non-image portion G4. FIG. 20 shows a profile in the primary scanning directions L1 to Ln of FIG. 19. When these are binarized by the predetermined threshold value (for example, 250) TH, the result is shown in FIG. 21 in which the output condition in the line sensor primary scanning direction is illustrated. Next, in order to make the judgment easy, a D type of flip flop 42 is used, and the waveforms shown in FIGS. 20 to 23 are generated. The following can be known from FIG. 22 in which the condition of the output 141 of the D type flip flop 42 is shown: the effective image region is started from the pixel at which Q output of D type flip flop 42, as shown in FIG. 12, is changed from L level to H level. The following can be known from FIG. 23 in which the condition of the output 140 of the D type flip flop 41 is shown: the end of the effective image region is the pixel at which Q output is converted from L into H.
There is a possibility that a negative film is not appropriately set at the film carrier. Therefore, as shown in FIG. 19, a predetermined interval is ensured between the lines, and the start and end points corresponding to n (for example, 10) lines are found, so that the accuracy of effective image region detection is improved. As described above, the start and end points of the effective image region corresponding to n lines, and the value of the previous lines and that of the present line are compared with each other, and the region is set a little inside so that the entire image can be set in the region. Therefore, the calculation is carried out (n-1) times so that a large value can be made to be a start point and a small value can be made to be an end point.
Next, with reference to FIG. 12 that is a circuit diagram of the image reading device, a substantial signal flow will be explained as follows.
The number of lines is counted by the line counter 9 at each line. When the number of counted lines has reached a predetermined number N, the start and end pixels of the effective image region are determined. The number of pixels is counted by the pixel address counter 8, and reset at each line by the primary scanning image effective signal 109. First, in the case of the start pixel of the effective image region, the operation is conducted as follows. The signal 107 obtained when the discrimination result signal 106 of the image portion (0) and the non-image portion (1) subjected to the pixel discrimination is reversed, is inputted into the D type flip flop 42, and the output 113 of the pixel address counter 8 obtained when the output signal 141 of Q of the D type flip flop 42 has risen from L level to H level that is, the start pixel of the effective image region is accommodated in the latch 11, and the image tip address value 114 at the longitudinal film position is stored in the memory 21.
In the case of the end pixel of the effective image region, the operation is conducted as follows. The signal 106 of the discrimination result of the image portion (0) and the non-image portion (1) subjected to pixel discrimination, is inputted into the D type flip flop 41, and the output 113 of the pixel address counter 8 obtained when the output signal 140 of Q of the D type flip flop 41 has risen from L to H, that is, the end pixel of the effective image region is accommodated in the latch 10, and the image tail address value 115 at the longitudinal film position is stored in the memory . 21.
Then, the start and end pixels of the effective image region corresponding to several lines (for example, 10) are found, and the previous line pixels and the found line pixels are compared with each other using the CPU 20. In order to set the region a little inside so that the entire image can be set in the region, in the case of the start pixel, the larger one is made to be a start pixel, and in the case of the end pixel, the smaller one is made to be an end pixel.
II-3-3 Determination of the Final Effective Image Region
It has been conventionally known that: in a photographic printer, the peripheral portion of an image is cut by 0.5 mm so that the entire image can be printed in the frame on a photographic paper. Therefore, also in this example, the lines disposed inside corresponding to 0.5 mm (8 lines) are calculated by the CPU, and thus obtained final effective image region is stored in the memory 21.
The region extracted as the effective image region is compared with an appropriate default value using the CPU. In the case where the difference is large or the effective image region can not be extracted, the default value is stored in the memory 21 as a final effective image region.
III Discrimination between Standard Photographing and Panoramic Photographing
FIG. 13 shows projected images of standard and panoramic photographing. As explained in item II-1 of the method for determining the effective image region of a pseudo panoramic negative film, FIGS. 24 to 27 show profiles in which portion L in FIG. 13 is binarized on the basis of the data discriminated between the image and non-image portions at each pixel. According to FIGS. 24 to 27, the number of pixels of the non-image portion of the image data 1 becomes approximately 0 in the standard photographing in both the longitudinal and lateral film positions. In the case of lateral pseudo panoramic photographing, the number of the lateral film width pixels is N which is the number of pixels of ne primary scanning line, and in the case of longitudinal pseudo panoramic photographing, the number of the lateral film width pixels is N'. Therefore, the number of pixels of image data 1 is different between the standard photographing and the pseudo panoramic photographing. Therefore, when the number of pixels of the image data 1 (non-image portion) is approximately 0, it is made to be the standard photographing, so that the standard photographing and the pseudo panoramic photographing can be discriminated.
Next, with reference to FIG. 12 that is a circuit diagram of the image reading device, a substantial signal flow will be explained as follows.
A portion of the region discriminating circuit is also used for the pseudo panoramic reference judgment.
Portion L in FIG. 13 is subjected to the pseudo panoramic reference judgment in line n. As explained in item II-3-1, the number of pixels is counted by the image discrimination counter 7 at each line. Therefore, the lateral start position signal 134 is sent to the selector 6 form the CPU 20, so that the non-image portion becomes 1 and the image portion becomes 0, and the non-image portion is counted by the image discrimination counter 7. Line n is sent to the comparator 14 as the pseudo panoramic reference discriminating line data 121. Then, line n is compared with the line counter output 116 sent from the line counter 9. When line n becomes the same as the line counter output, the number 112 obtained by the image discriminating counter 7 is sent to the CPU 20 from the interface 19 by the pseudo panoramic reference discriminating line timing signal 122. When this number 112 of the image discriminating counter is, for example, 0, it is judged that the standard photographing is conducted, and when the number 112 is not 0, it is judged that the panoramic photographing is carried out.
IV Method for Removing an Unnecessary Image Portion
A region that has been judged not to be an effective image region by the region discriminating section 436 in FIG. 5, an image signal outputted from-the image processing section is forcibly made to be 0 in the case of a negative film, so that the unnecessary image portion can be removed.
In this example, the present invention is applied to a projector type of image reading device. Of course, the same effect can be provided when the present invention is applied to a scanner type of image reading device.
As described above, the present invention is to provide an image reading device, comprising: an image reading means to read image information on a standard photographing negative film and a pseudo panoramic photographing negative film; and a removing means to remove an unnecessary portion from the image information sent from said image reading means, said unnecessary portion being a portion except for a pseudo panoramic photographed portion. Therefore, both the standard photographing film and the pseudo panoramic photographing negative film can be read using a negative film carrier for standard photographing use. Therefore, an operator can read the negative film information without giving consideration to the photographing conditions of pseudo panoramic photographing and standard photographing.
As described above, the image reading device of the present invention comprises: an image reading means to read image information of a standard photographic image and a pseudo panoramic photographic image, both said standard photographic image and said pseudo panoramic photographic image existing on a negative film; a discriminating means to discriminate between standard photographing and pseudo panoramic photographing from the image information sent from the image reading means; and a removing means to remove an unnecessary portion from the discrimination results obtained by said discriminating means, said unnecessary portion being a portion except for a pseudo panoramic photographed portion. Therefore, only when a negative film carrier for standard photographing is used for a film in which both a standard photographed image and a pseudo panoramic photographed image are provided, the pseudo panoramic photographed image can be read. Therefore, an operator can read the negative film information without giving consideration to the photographing conditions of pseudo panoramic photographing and standard photographing.
In the image reading device of the present invention, said removing means is characterized in that: the unnecessary portion except for a pseudo panoramic photographed portion is removed by region discrimination; and in the case where the region discrimination can not be carried out, the unnecessary portion except for a pseudo panoramic photographed portion is removed using a predetermined region. Therefore, even when it is impossible to carry out region discrimination, an operator can read the negative film information without giving consideration to the photographing conditions of pseudo panoramic photographing and standard photographing.
FIG. 29 shows an example of the image signal processing circuit diagram of the color image reading device illustrated in FIG. 3, and the second object of the invention can be accomplished by this circuit.
Numerals 1 to 3 are CCD line sensors for inputting an image. This CCD line sensor includes an array of CCDs in which a plurality of photoelectric conversion elements are aligned on a line. Image information signals outputted from the CCD line sensors 1 to 3 are amplified by the amplifiers 4 to 6 provided for each color. Then, the signals are converted into digital signals of R, G and B, so that the signals are changed into a line of time series signals for each color. This time series signal is inputted into the shading correcting section 10.
This shading correcting section 10 is controlled by the CPU 11 to which the line memory 12 is connected. This line memory 12 has the following function: in order to correct the dispersion of sensitivity of the CCD line sensors 1 to 3, and also in order to correct the unevenness of the amount of light irradiated by the light source, the shading data of R, G and B of one line of CCD is stored for each pixel, and this line memory 12 is composed of a semiconductor random access memory RAM. In the shading correcting section 10, calculation is conduced between the image signal and the shading data read out from the line memory 12 in accordance with a control signal sent from the CPU 11, so that the correction of fluctuation of the output signal in the primary scanning direction is carried out, and also the correction of white balance of R, G and B is carried out.
The CPU 11 is connected with the sampling position storing RAM 13, the exposure control data storing RAM 14, and the shading data withdrawal RAM 15. The sampling position storing RAM 13 stores sampling positions for the shading data and exposure control data that will be described later. The exposure control data storing RAM 14 stores exposure control data for discriminating the film exposure condition. The shading data withdrawal RAM 15 temporarily withdraws the shading data stored in the line memory 12. The CPU 11 makes access to each of them.
Next, with reference to FIG. 30, a reading operation of this image reading device will be explained as follows. FIG. 30 is a flow chart showing the control procedure.
Setting of Pseudo Panoramic Photographing Mode and Standard Photographing Mode
First, in step S1, the operation of a copy key is discriminated. In the case where the copy key is in a state of ON, the operations are conducted as follows. Since there are two kinds of negative films, one is a standard photographing negative film F1 shown in FIG. 1, and the other is a pseudo panoramic negative film F2, it is necessary to discriminate the reading mode of standard photographing negative film F1 and that of pseudo panoramic photographing negative film F2 in step S2. Therefore, mode setting is conducted by the key of the device. In this example, the mode setting is conducted when a command is inputted through the key. However, the mode setting may be conducted by discriminating between standard photographing and pseudo panoramic photographing by means of image processing.
Standard Photographing Mode
Next, when the standard photographing mode is selected in step S2, an unexposed frame of the film base is set in the negative film carrier 202 shown in FIG. 28, and the negative film carrier 202 is inserted from insertion opening of the projector in the same direction as that of the photographing direction of standard photographing negative film F1. It is checked in step S31 that the base film has been set, and then the scanning of shading is started. Positional data X1 disposed close to the center between edge portions L1 and L2 shown in FIG. 31 is sent from the sampling position storing RAM 13 shown in FIG. 29. The sampling of shading data is conducted in step S32 by a sampling signal sent from the CPU 11 on the basis of the aforementioned positional data X1.
Usually, the shading data corrects the distribution of the amount of irradiating light and the dispersion of sensitivity of individual line sensor elements (arrays of photoelectric conversion element). In addition to that, in the case of shading of a negative film, the orange masking of the negative film is corrected, and the shading is conducted using the unexposed portion of the film in order to effectively use the dynamic range, so that the color data corresponding to the orange mask can be removed. In this case, in order to improve the accuracy, a plurality of lines are sampled, and the obtained data is averaged using the CPU 11 so as to find the final shading data. Then, the data is stored in the line memory 12 shown in FIG. 29.
After the scanning of shading has been completed, standard photographing negative film F1 is set in the negative film carrier 202. This negative film carrier 202 is inserted from the insertion opening of the projector, that is, the negative film carrier 202 is inserted in the same direction as that of shading.
It is checked in step S33 that standard photographing negative film F1 has been set. It is discriminated in step S34 whether the copy button is pressed or not. After it has been confirmed that the copy button was pressed, prescanning is started first. In order to appropriately read the projected image, the exposure control data to correct various conditions of a standard photographing negative film is taken in step S35.
Usually, the latitude of a standard photographing negative film is wide, so that it is necessary to print the negative films of various exposure conditions from over-exposure to under-exposure, and the printed conditions must be approximately the same. The exposure condition when the negative film was photographed is not known. Therefore, it is necessary to sample the image density of the negative film so as to adjust the exposure mount to be given to the negative film, so that the exposure control data is taken. For example, the amount of light irradiated by a lamp is varied in accordance with the exposure control data so that the exposure amount given onto the negative film is changed. Accordingly, the amount of light irradiated on the reading element is made equal with respect to negative films of over-exposure and that of under-exposure so as to provide prints in the same condition.
When the sampling operation for image density is conducted in a range as wide as possible, the accuracy of exposure control, that is, the conversion from negative to positive can be improved.
In the case of standard photographing negative film F1, a sampling operation is started by a sampling signal sent from the CPU 11 in accordance with the positional data of edge portion L1 shown in FIG. 32 sent from the sampling position storing RAM 13 illustrated in FIG. 29, and then the sampling operation is continued to edge portion L2. In this example, sampling of the exposure control data is carried out from edge portion L1 to edge portion L2, however, sampling of the exposure control data may be conducted only on a portion from edge portion L1 to edge portion L2.
Finally, in step S36, image portion A of standard photographing negative film F1 is read with the aforementioned method.
Pseudo Panoramic Photographing Mode
When the pseudo panoramic photographing mode is selected in step S2, pseudo panoramic photographing negative film F2 is set in the negative film carrier 202, and this negative film carrier 202 is inserted from the lateral insertion opening of the projector. It is confirmed in step S3 that pseudo panoramic photographing negative film F2 has been set, and it is discriminated in step S4 whether the copy button has been pressed or not. When it is confirmed that the copy button has been pressed, a prescanning operation is started, and shading data is taken in step S5.
Shading is carried out for the reason explained in the paragraph of reading of standard photographing negative film F1. As shown in FIG. 33, in the case of pseudo panoramic photographing negative film F2, shading is carried out using non-image portion B disposed between L3 and L3, and also using non-image portion C disposed between L5 and L6.
Next, as explained in the paragraph of reading of standard photographing negative film F1, in order to appropriately read the projected image, exposure control data to correct various conditions of pseudo panoramic photographing negative film F2 is taken in step S6. When the sampling operation for image density on pseudo panoramic photographing negative film F2 is conducted in a range as wide as possible, the accuracy of exposure control can be improved. Therefore, exposure control data is collected in a range from L4 that is the start of image portion A, to L5 that is the end of image portion A as shown in FIG. 34.
For example, prescanning is started, and positional data disposed close to the center between edge portions L3 and L4 shown in FIG. 9 is sent from the sampling position storing RAM 13 shown in FIG. 29. The sampling of shading data is conducted in step S5 by a sampling signal sent from the CPU 11 on the basis of the aforementioned positional data. Next, a sampling-operation of exposure control data is conducted in the CPU 11 in accordance with the positional data between L4 and L5 shown in FIG. 33 sent from the sampling position storing RAM 13, and the exposure control data is stored in the exposure data storing RAM 14 shown in FIG. 29. That is, both shading data and exposure control data are taken in a series of prescanning operation.
In this case, in order to improve the accuracy of sampling of exposure control data, the sampling operation is carried out in a region from L4 to L5, that is, the sampling operation is carried out in the image portion of the pseudo panoramic photographing negative film. However, the sampling operation may be carried out only in a portion from L4 to L5, depending on an image. That is, depending on an image to be read, a sampling position to sample the exposure control data stored in the sampling position storing RAM 13 shown in FIG. 29 may be changed. Finally, image portion A of pseudo panoramic photographing negative film F2 is read in step S7 in accordance with the exposure control data.
As described above, the device of the present invention includes a shading correction means that conducts shading correction using a non-image portion of a pseudo panoramic negative film, in which an image is not photographed. Therefore, in the case where image information of the pseudo panoramic negative film is read and processed, shading correction can be carried out using the non-image portion on the pseudo panoramic negative film, in which an image is not photographed. Accordingly, it is not necessary to prepare an unexposed spare frame, and shading can be carried out in the same exposed frame on the pseudo panoramic negative film. Therefore, when the film is developed, the conditions become the same, and color reproduction can be precisely conducted. Since shading correction is conducted in the same frame on the pseudo panoramic photographing film, the preserving conditions become the same, so that shading correction can be accurately carried out as compared with a case in which an unexposed frame is used for shading correction.
As described above, the device of the present invention includes an exposure control means in which only a photographed image portion on a pseudo panoramic photographing film is used for exposure control data. Therefore, in the case where the image information of the pseudo panoramic photographing film is read and subjected to image processing, only the photographed image portion on the pseudo panoramic photographing film is used for the exposure control data. Since only the exposure control data of the image portion on the pseudo panoramic photographing film is read, exposure control can be precisely conducted, and further negative-positive reversal can be precisely carried out.
The device of the present invention includes a means to take the shading correction data and the exposure control data during a prescanning operation conducted before image information of a pseudo panoramic photographing film is read. Therefore, when image information of the pseudo panoramic photographing film is read and processed, the shading data and exposure control data can be taken while the prescanning operation is being conducted on the pseudo panoramic photographing film. Accordingly, the shading operation can be conducted in one prescanning operation, so that it is not necessary to separately conduct the shading operation. Consequently, an operator can read image information without giving consideration to shading correction. Further, exposure control data can be read only from the photographed image portion. Therefore, exposure control can be precisely conducted, and negative-positive reversal can be accurately carried out.
FIG. 35 is a flow chart showing a variation of the device illustrated in FIG. 30. Third object of the present invention can be accomplished by this example.
When the pseudo panoramic photographing mode is selected in step S2, pseudo panoramic photographing film F2 is set in the film carrier 202, and this negative film carrier 202 is inserted from the lateral insertion opening of the projector. It is confirmed in step S3 that pseudo panoramic photographing negative film F2 has been set, and it is discriminated in step S4 whether the copy button has been pressed or not. When it is confirmed that the copy button has been pressed, a primary scanning operation is started, and shading data is taken in step S5.
Shading is carried out for the reason explained in the paragraph of reading of standard photographing negative film F1. As shown in FIG. 33, in the case of pseudo panoramic photographing negative film F2, shading is carried out using non-image portion B disposed between L3 and L3, and also using non-image portion C disposed between L5 and L6. For example, prescanning is started, and positional data disposed close to the center between edge portions L3 and L4 shown in FIG. 9 is sent from the sampling position storing RAM 13 shown in FIG. 5. The sampling of shading data is conducted in step S5 by a sampling signal sent from the CPU 11 on the basis of the aforementioned positional data. After the shading correction has been carried out in non-image regions B and C on this pseudo panoramic photographing negative film F2, image region A is read under the same condition (step S6).
That is, the information processing section 400 of this image reading device includes a means that conducts the shading correction in non-image portions B and C on the pseudo panoramic photographing negative film F2, and reads image portion A under the same condition. In a conventional image reading device, after the shading and exposure control has been conducted in a prescanning operation, pseudo panoramic photographing negative film F2 is read in a primary scanning. That is, it is necessary to prescanning and primary scanning operations. However, in the image reading device of the present invention, it is not necessary to conduct exposure control if the exposure conditions-are already known, so that both shading and reading can be carried out by one scanning operation. As a result, the camera performance can be improved, and exposure control can be precisely conducted. Therefore, the exposure condition of a photographed film is appropriate, so that it not necessary to check the exposure condition. Both shading and reading can be carried out by one scanning operation, and accordingly a film reading operation can be simplified.
Also, the information processing section 400 of this image reading device includes a means that conducts image reading in the following manner: when pseudo panoramic photographing negative film F2 is read a plurality of times, in the second image reading operation and after that, the shading data of the first image reading operation is utilized. Also when image reading is conducted a plurality of times by the conventional image reading device, shading and exposure control are conducted in a prescanning operation, and then pseudo panoramic photographing negative film F2 is read. Therefore, the shading operation is conducted a plurality of times in the conventional device. According to the present invention, it is sufficient to conduct the shading operation only once. Therefore, the image reading operation can be simplified.
Also, the information processing section 400 of this image reading device includes a means that conducts image reading in the following manner: when pseudo panoramic photographing negative film F2 is read a plurality of times, the shading data of the first image reading operation is utilized in the second image reading operation and after that. According to the conventional image reading device, in the case where the same frame is read a plurality of times, the circumstances of pseudo panoramic photographing negative film F2 are checked each time. However, since the frame is the same, the conditions of shading and exposure are not changed. Therefore, when the second operation and after that can be conducted using the data of the first operation. In this way, the reading operation can be simplified.
Also, the information processing section 400 of this image reading device includes a means that conducts image reading in the following manner: when pseudo panoramic photographing negative film F2 is read a plurality of times, shading data is collected once in a plurality times. Therefore, image quality can be maintained by the minimum correcting operation. The minimum correcting operation is as follows: when pseudo panoramic photographing negative film F2 is read a plurality of times, shading correction data is collected once in a plurality of times, and the new shading correction data is stored in the memory for the successive shading correction.
FIG. 36 shows a flow chart of this image reading operation. In step a, the number of copies is set. In this example, the number is determined to be n1. Next, in step b, it is judged whether the copy button is turned on or not. In the case of ON, the program advances to step c. In step c, shading data is collected, and in step d, exposure control data is collected. Next, in step e, shading is conducted with the counter 2 that counts the number of copies. After that, the counters 1 and 2 that count the number of copies are respectively set at 0. After shading has been conducted in step f, the counted number of the counter 1 is compared with n2 that has been previously set. In the case where the counted number of the counter 1 is n2, the program advances to step g, and shading data is collected. Then, the counter 1 is set at 0 in step h. In the case where the counted number of the counter 1 is n2, or after step h, the program advances to step i, and pseudo panoramic photographing negative film F2 is read. Then, in step j, the counted number of the counter 1 is increased by 1, and in step k, the counted number of the counter 2 is increased by 1. Finally, in step l, the counted number of the counter 2 is compared with n1 that was set in step a. In the case where the counted number of the counter 2 is not n1, the program advances to step f, and in the case where the counted number of the counter 2 is n1, the copy operation is completed.
As described above, each time the copy operation is conducted n2 times, the shading correction is conducted once.
As described above, after the shading correction has been conducted in the non-image portion of a pseudo panoramic photographing negative film, the image portion is read under the same condition. Therefore, it is not necessary to conduct exposure control if the exposure conditions are already known, so that both shading and reading can be carried out by one scanning operation. As a result, the reading operation can be simplified.
This image reading device includes a means that conducts image reading in the following manner; when a pseudo panoramic photographing negative film is read a plurality of times, the shading data of the first image reading operation is utilized in the second image reading operation and after that. Also when image reading is conducted a plurality of times by the conventional image reading device, shading and exposure control are conducted in a prescanning operation, and then the pseudo panoramic photographing negative film is read. Therefore, the shading operation is conducted a plurality of times in the conventional device. According to the present invention, it is sufficient to conduct the shading operation only once. Therefore, the image reading operation can be simplified.
In the case where the same frame of a pseudo panoramic photographing film is read a plurality of times, in the second time and after that, the shading data or exposure control data of the first time is used for reading, or the shading data and exposure control data of the-first time are used for reading. Since the frame is the same, the shading and exposure conditions are not changed. Therefore, when the data of the first time is used in the second time and after that, the reading operation can be simplified.
When a pseudo panoramic photographing negative film is read a plurality of times, the shading data is collected once in a plurality of times. Therefore, image quality can be maintained by the minimum correcting operation.
With reference to the attached drawings, an example to accomplish the fourth object of the present invention will be explained as follows.
FIG. 37 is a schematic illustration showing the structure of an image reading device for pseudo panoramic films according to the present invention.
FIG. FIG. 37, the film insertion detecting sensors 801, 802 are provided in the projector 803. As shown in FIG. 38(a), the film insertion detecting sensors 801 detects that the film carrier 822 is inserted in a direction so that the longitudinal direction of the pseudo panoramic film 821 can coincide with the primary scanning direction. As shown in FIG. 38(b), the film insertion detecting sensors 802 detects that the film carrier. 822 is inserted in a direction so that the lateral direction of the pseudo panoramic film 821 can coincide with the primary scanning direction.
The paper size designation operating section 804 selects between an automatic mode and a manual mode. In the automatic mode, A4 papers (the lateral side is long) or A4R papers (the longitudinal side is long) are selected in accordance with the inserting direction of the film carrier 822, which will be described later. In the manual mode, papers of an arbitrary size are selected. In this example, papers of A4 size are used, however, papers of other sizes may be used.
The magnification designating operating section 805 selects between an automatic mode and a manual mode. As described later, in the automatic mode, the magnification is calculated and set in accordance with the inserting direction of the film carrier 822 by a predetermined equation. In the manual mode, an arbitrary magnification can be inputted.
The printing position designating operating section 806 selects between a centering mode by which printing can be conducted in the center of the paper and a frame designation mode by which a plurality of prints can be conducted on a paper.
The film and paper size memory 807 previously stores the sizes of various films that can be read, and also stores the sizes of papers that can be used. The paper size holding section 808, the magnification holding section 809 and the printing position holding section 810 are composed of a RAM. The paper size, the printing magnification, and the designated printing position such as centering are respectively stored the RAMS.
According to the outputs of the film insertion sensors 801, 802, the paper size designation operating section 804, the magnification designating operating section 805 and the printing position designating operating section 806, and further according to the stored data of the film and paper size memory 808, the paper size, the print magnification and the printing position are respectively determined by the CPU 11, and the determined data are stored in the paper size holding section 808, the magnification holding section 809 and the printing position holding section 810. When the frame designation mode is selected by the printing position designation operating section 806, the number of images to be printed on a paper and the position of a frame on the paper are indicated by the printing frame number indicator 812. In this case, the CPU 11 includes the functions of: a paper determination means to determine the paper in accordance with the inserting direction of the film carrier 822; a printing magnification determining means; a printing position control means; a calculation means to calculate the number of panoramic images that can be printed on the paper, in accordance with the designated paper size; and a designation means to designate the printing position of an image when the calculated number of images is plural.
Next, the operation of the image reading device of this example will be explained as follows.
First, a case in which the paper size and magnification are automatically designated, will be explained as follows.
For example, in the case where the film carrier 22 is inserted in a lateral direction as shown in FIG. 38a, the film insertion sensor 1 detects the film carrier 22, and an ON signal is inputted into the CPU 11. Then, the paper size of A4 is selected by the CPU 11, and the selected paper size A4 is temporarily stored in the paper size holding section 808.
The CPU 11 reads the length of the lateral direction of the inserted pseudo panoramic film (the longitudinal direction of the film), and the length of the lateral direction of the selected A4 paper from the paper size storing section 807, and then magnification Z is calculated by the following equation (1) .
Z=(lateral length of paper)/(lateral length of projected image on film)(1)
The result of calculation is temporarily stored in the magnification holding section 809.
In the case where the paper size and magnification are automatically designated, the number of images printed on a paper is 1, and the centering mode is designated by the printing position designating operation section 806, and then the image is printed in the center of the paper.
This centering operation is carried out in the following manner: as shown in FIG. 39, the CPU 11 calculates the image position so that center Cf of film image A can be superimposed on center Cf of paper B. Then, the determined printing position is temporarily stored in the printing position holding section 810.
Next, in the case where the film carrier 822 is inserted in the longitudinal direction as shown in FIG. 38b, the film insertion detecting sensor 802 detects the film carrier 822, and an ON signal is inputted into the CPU 11. Then, paper size A4R is selected by the CPU 11, and this selected paper size A4R is temporarily stored in the paper size holding section 808.
The CPU 11 reads-the length of the longitudinal direction of the inserted pseudo panoramic film (the longitudinal direction of the film), and the length of the longitudinal direction of the selected A4 paper from the paper size storing section 807, and then magnification Z is calculated by the following equation (2).
Z=(longitudinal length of paper)/(longitudinal length of projected image on film) (2)
The result of calculation is temporarily stored in the magnification holding section 809.
Then, the centering mode is designated by the printing position designating section 806 so that the printing position is determined in the same manner as described above, and the determined printing position is temporarily stored in the printing position holding section 810.
According to the paper size, magnification and printing position determined in the aforementioned manner, a projected image of the pseudo panoramic film is printed on the paper.
In the case where the paper size and magnification are manually designated, irrespective of the output of the film insertion detecting sensor 812, the designated paper and magnification are selected by the paper size designation operating section 804 and the magnification designation operating section 805, and they are stored in the holding sections 808, 809. In the case where-the image overflows the paper when the magnification has been manually designated, a warning is previously given.
For example, in the case where the film carrier 822 is laterally inserted as shown in FIG. 38a and the paper size is manually designated to be A4R, the panoramic image is extremely long in the lateral direction, so that a plurality of panoramic image can be printed on one A4R paper at the magnification in which the panoramic image is can be set on the paper.
When the frame designation mode is selected by the printing position designation operating section 806 in this case, the CPU 11 calculates the number of panoramic images that can be printed on the paper, the size of which has been designated. For example, in the case where 3 frames can be printed on the paper, the result of the calculation is displayed on the printing frame position display device 812 as shown in FIG. 40. Then, the printing position designating operating section 806 designates a frame among the frames 1, 2 and 3 displayed on the printing frame position display 12, in which the presently projected panoramic image is to be printed. Then, the designated position is temporarily stored in the printing position holding section 810. For example, in the case where the frame 3 is designated, the image is printed in the lowermost third frame on paper B shown in FIG. 4.
As a result of the foregoing, a plurality of sheets of panoramic images can be printed on one sheet of paper. Therefore, papers can be economized.
The projection type of image reading device is applied to this example. Of course, when the present invention is applied to a scanner type of image reading device, the same effects can be provided.
As explained above, the present invention can provide an image reading device suitable for reading an image on a panoramic film, the lateral size of which is extremely long compared with a standard size film.
Also, a plurality of sheets of images can be printed on one paper, so that panoramic images can be effectively printed without wasting papers. Therefore, waste of papers can be avoided.
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In an apparatus for reading a photographed image on a standard size negative film, wherein the photographed image includes a standard size image and a pseudo panoramic image, and wherein the pseudo panoramic image includes an exposed image region and an unexposed non-image region, the apparatus includes an image reader to photoelectrically read an image of a film and to ouput image signals, a circuit to process the image signals and to determine an image region and a non-image region on the image of the film, and the circuit eliminates image signals corresponding to the non-image region.
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RELATED APPLICATIONS
[0001] This application is a continuation-in-part of U.S. patent application Ser. No. 13/909,820 filed Jun. 4, 2013, which claims the benefit of U.S. Provisional Application No. 61/655,055 filed Jun. 4, 2012, all of which are hereby incorporated herein by reference.
FIELD OF INVENTION
[0002] The present invention relates generally to pilot operated valves, and more particularly to a low power pilot operated valve actuated by a piezoelectric actuator that enables use of the valve in locations remote from utility-supplied power.
BACKGROUND
[0003] Pilot-operated valves utilize system pressure to create force imbalances within the valve to open or close the main piston, or poppet, which in turn controls flow through the main port of the valve. Control of the pilot flow typically is done with a solenoid coil for on/off valves, or some type of pressure sensing device such as a spring-loaded diaphragm for pressure regulating control valves.
[0004] Both of the conventional methods of controlling pilot operated valves have drawbacks. Solenoid, or on/off valves, utilize coils which consume large amounts of power and are unreliable over millions of cycles. Mechanically-operated pressure regulating valves are slow to respond, and are reactive to system pressure changes.
SUMMARY OF INVENTION
[0005] The present invention provides a piezo-actuated pilot valve that takes advantage of the small compact size and low power requirement of piezo technology to control the pilot flow in a pilot-operated valve. Exemplary piezo-actuated valves can be operated using a relatively low voltage power supply, such as a battery or a solar cell. This enables usage of the valve in remote locations that do not have a ready source of utility-supplied electrical power. The piezo-actuated pilot valve also can have a programmable controller and/or can have an antenna that allows the valve to be controlled wirelessly.
[0006] According to one aspect of the invention, a pilot valve includes a first port in selective fluid communication with a second port by a passageway through the valve; a valve seat; a movable piston selectively engagable with the valve seat to close the valve when the valve member engages the valve seat and to open the valve when the valve member is spaced from the valve seat; a pilot passageway providing a pathway to a portion of the piston opposite the side that engages the valve seat, the pathway being opened and closed by a pilot plug; and a piezo unit operable to control movement of the pilot plug to control whether the pathway is opened or closed.
[0007] Optionally, the piezo unit is powered by a battery.
[0008] Optionally, the battery is a rechargeable battery.
[0009] Optionally, the pilot valve includes a solar panel electrically coupled to the battery for recharging the battery.
[0010] Optionally, the pilot valve includes a solar panel electrically coupled to the piezo unit for providing power to the piezo unit.
[0011] Optionally, the pilot valve includes an antenna for receiving a wireless signal.
[0012] Optionally, the valve is wirelessly controlled.
[0013] Optionally, the pilot valve includes a controller for controlling the piezo unit.
[0014] The foregoing and other features of the invention are hereinafter described in greater detail with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is a cross-sectional view of an exemplary embodiment of a piezo-actuated pilot valve.
[0016] FIG. 2 is a cross-sectional view of another exemplary embodiment of a wireless piezo-actuated pilot valve.
[0017] FIG. 3 is a cross-sectional view of still another exemplary embodiment of a piezo-actuated pilot valve.
[0018] FIG. 4 is an enlargement of a bonnet portion of the valve of claim FIG. 3 .
DETAILED DESCRIPTION
[0019] An exemplary embodiment of a piezo-actuated pilot valve 10 is shown in FIG. 1 . The pilot valve 10 includes a first port 11 in selective fluid communication with a second port 13 by a passageway through the valve 10 . A movable valve member (main piston plug) 18 is selectively engagable with the valve seat 19 to close the valve 10 when the valve member 18 engages the valve seat 19 and to open the valve 10 when the valve member 18 is spaced from the valve seat 19 . A pilot passageway 16 provides a pathway to a portion of the valve member 18 opposite the side that engages the valve seat. The pathway is opened and closed by a pilot plug 14 .
[0020] The valve 10 includes a smart material 12 operable to control movement of the pilot plug to control whether the pathway 16 is opened or closed. The smart material 12 may be, for example, a piezoelectric material. The stack 12 may also be referred to herein as a “wafer” or “piezo unit”. The piezo unit 12 controls movement of a pilot plug/cartridge 14 , which can include a small mechanical pilot assembly which in turn controls the pilot flow via pilot passageway 16 to or from the main piston 18 or poppet of the valve. The main piston engages/disengages a valve seat 19 to open/close the valve. Controlling the pilot flow controls the pressure imbalances on the main piston/poppet, forcing it open or closed.
[0021] The piezo unit is a highly reliable, precise unit which draws very little power to operate. Power supply to these units is typically 12 or 24 volts with current draws less than one milliamp. The piezo unit can therefore be powered by a low power energy source, such as battery power, solar power, or another energy source. The movement of the piezo stack is proportional to the amount of energy that is supplied. The energy supplied can be full power for maximum movement to be used in on/off applications, or proportional from a controller based on feedback from any type monitoring system producing a 4-20 Ma or 0-10 V signal. Thus, the piezo unit takes the place of large electrical coils, or mechanical pressure sensing devices such as springs.
[0022] The piezo unit should, preferably, be isolated or sealed away from the operating fluid, especially in refrigerant applications.
[0023] Because of the low power consumption of the piezo unit, it is possible for the unit to be powered by an on-board battery 20 integral to the valve assembly, as shown in FIG. 2 .
[0024] Because many valves are located outside, the battery can be recharged through a solar panel 22 on the valve. Piezo units also give off electrical charges when they are moved, such as with the vibrations from piping; this may also be a means of collecting energy to keep the battery charged to operate the valve. Coupling this technology with wireless technology to send the valve control signals, the valve can be operated without any wires for power or control.
[0025] For example, as shown in FIG. 2 , the pilot valve can include an antenna 20 for receiving a wireless signal for controlling the valve. Accordingly, the valve disclosed herein can be a totally wireless powered and actuated control valve, and can lead to energy savings from reduced power consumption to operate solenoid coil operated valves. The valve also may include a programmable controller 24 with, for example, one or more LEDs.
[0026] Referring now to FIGS. 3 and 4 , another exemplary pilot valve is indicated generally at 30 . The pilot valve 30 includes a valve body 31 having an inlet port 32 and an outlet port 33 connected by a passageway 34 . The passageway 34 extends through a valve seat 36 , the opening of which is open and closed by a main valve member 37 that is mounted in the valve body 31 for movement into and out of engagement with the valve seat. The main valve member may include an annular resilient seal 38 for effecting sealing engagement with the valve seat 36 . The main valve member is biased by a spring 39 toward and against the valve seat. The spring 39 is disposed in a piston chamber 40 in the valve body between the main valve member and the underside of a bonnet body 42 . The bonnet body may be attached to a lower portion of the valve body 31 by any suitable means, such as bolts (not shown).
[0027] In the illustrated embodiment, the main valve member 37 , which can also be referred to as a main poppet valve, has a tubular central portion 44 that surrounds an interior chamber 45 closed at its end nearest the valve seat 36 by a valve end wall 46 and at its upper end by a piston head 47 . The tubular central portion 44 is guided by a guide sleeve ring 49 that is retained in an annular groove in the valve body 31 and the piston head 47 that is sealed by a suitable seal 50 to the interior wall of the piston chamber 40 . The piston head 47 divides the piston chamber 40 into a valve side chamber 53 and a control chamber 54 . The valve side chamber 53 is in fluid communication with the inlet port via one or more passages 57 provided in the wall of the tubular central portion 44 . Consequently, fluid pressure at the inlet port 32 will act on the side of the piston head 47 nearest the valve seat 36 in a direction wanting to move the main valve member to an open position thereby opening the pilot valve for flow of fluid from the inlet port to the outlet port 33 . The piston head preferably has an effective cross-sectional area greater than the effective cross-sectional area of the valve seat opening.
[0028] In the illustrated embodiment, the piston head 47 is provided with an orifice 61 allowing metered flow from the valve side chamber 53 to the control chamber 54 , although it will be understood the orifice may be located elsewhere such as in passageway in the valve body connecting the control chamber to a location upstream of the valve seat 36 . Metered flow will result in a net force (fluid pressure and the force of the spring 39 ) acting to hold the main valve member closed against the valve seat for blocking flow through the valve.
[0029] The main valve member 37 can be caused to move away from the valve seat 36 by bleeding off fluid pressure from the control chamber 54 . This is accomplished by a peizo unit 66 that controls movement of a pilot valve member 67 . The pilot valve member controllably blocks and permits flow from the control chamber 54 to a location downstream of the valve seat 36 which will be at a lower pressure than the inlet pressure. As described in greater detail below, energization of the piezo unit will cause the pilot valve member to move into and out of engagement with a pilot valve seat 69 surrounding a passage 70 that connects the control chamber 54 to the downstream side of the main valve seat 36 , and more particularly to the passage 34 downstream of the main valve seat 36 . That is, bleeding off pressure from the control chamber 54 will allow the pressure in the chamber 53 to push the poppet upwards opening the main valve. Conversely, stopping pressure from being bled off from the control chamber 54 will allow the pressure to build up in the control chamber again causing the poppet to move to its closed position.
[0030] Alternate closing and opening of the pilot valve member (poppet) 67 can be time-modulated to create a pilot valve duty cycle that is something less than full-time open (or full closed), the duty cycle determining how much the pressure is reduced in the control chamber 54 . The reduced pressure in the control chamber will cause the main control valve 37 to open by a proportionate amount.
[0031] In the illustrated embodiment, the piezo unit 66 and pilot valve member may be conveniently provided on or in the bonnet body 42 . The pilot valve member 67 and associated pilot valve seat 69 are preferably provided as part of a cartridge valve assembly 71 including a pilot valve sleeve 72 that is threaded into a bore in the bonnet body. The pilot valve member 67 is axially movable in the sleeve 72 and normally is biased by a pilot valve spring 74 toward an open position. The pilot valve member may have a radially outwardly protruding annular sealing portion 75 that engages and seals against the pilot valve seat 69 formed by a shoulder on pilot valve sleeve 72 . When engaged with the pilot valve seat, the pilot valve member blocks flow through the passage 74 that connects the control chamber with the main valve passage 34 downstream of the main valve seat 36 , and thus with the outlet port 33 .
[0032] The peizo unit 66 includes a smart material operable to control movement of the pilot valve member 67 (pilot plug or pilot valve). The smart material may be, for example, a piezoelectric material such as a piezoelectric wafer or stack. The piezoelectric material is operatively engaged with the pilot valve member. In the illustrated embodiment, the piezoelectric material engages an axial end of the pilot valve member opposite the pilot valve spring 74 which holds the axial end of the pilot valve member against the piezoelectric material. The piezoelectric material preferably is located in a cover member 79 attached to bonnet body 42 by suitable means, such as by the fasteners 80 . A metal diaphragm 82 preferably is sandwiched between the piezoelectric material and pilot valve member, as well as between the cover and bonnet body, to fluidically isolate the piezoelectric material from fluid in the bonnet body. The piezoelectric material has electrical leads 83 associated therewith for connection to a controller 84 , which may be assembled with or attached to the cover, or located remotely if desired. The controller senses, by means of a suitable sensor(s), the pressure being controlled and causes the peizo unit to open and close the pilot valve member very quickly to control the pressure in the control chamber 40 which ultimately controls the position of the poppet 37 . The controller may employ a basic proportional-integral-derivative (PID) loop to control the piezo position and valve poppet position. As seen in FIGS. 3 and 4 , the valve 30 may be provided with a manual bypass feature. The manual bypass feature includes a manually operated valve member 85 that opens and closes a bypass passage 86 connecting the control chamber 54 to the passage 74 that connects to the passage downstream of the main valve seat (although it will be appreciated that the passage 86 may independently connect to the passage 74 downstream of the main valve seat 36 ). The manual valve member 85 may a valve portion 87 that engages a valve seat 87 to close the bypass passage 87 and a threaded stem portion 88 threaded into the bonnet body 42 . The outer end of the valve member may protrude outwardly from the bonnet body and be provided with wrenching surfaces 89 so that a wrench can be engaged with the valve stem portion 88 to rotate the valve member for opening and closing the bypass passage. The valve stem can be sealed by suitable means to the bonnet body and the outwardly protruding portion of the valve stem may be covered by a cap 91 or the like.
[0033] As above mentioned, the piezo unit 66 is a highly reliable, precise unit that draws very little power to operate. Power supplied to suitable units is typically 12 or 24 volts with current draws less than one milliamp. The piezo unit, as well as the controller, can therefore be powered by a low power energy source, such as battery power, solar power, or another energy source, as in the same manner as described above in connection with the FIGS. 1 and 2 embodiments. The movement of the piezo stack is proportional to the amount of energy that is supplied. Usually the current supplied to the peizo unit is controlled by the controller. The energy supplied can be full power for maximum movement to be used in on/off applications, or proportional from a controller. The controller will usually use feedback from any type monitoring system, which may monitor pressures and/or flow, particularly downstream of the main valve seat
[0034] Because of the low power consumption of the piezo unit, it is possible for the unit to be powered by an on-board battery and the battery can be recharged through a solar panel 22 on the valve. This makes the valve particularly suitable for use at locations where utility supplied power is not readily available.
[0035] Piezo units also give off electrical charges when they are moved, such as with the vibrations from piping; this may also be a means of collecting energy to keep the battery charged to operate the valve. Coupling this technology with wireless technology to send the valve control signals, the valve can be operated without any wires for power or control.
[0036] Like in the embodiment of FIGS. 1 and 2 , the pilot valve of FIGS. 3 and 4 can include an antenna for receiving a wireless signal for controlling the valve. Accordingly, the valve disclosed herein can be a totally wireless powered and actuated control valve, and can lead to energy savings from reduced power consumption to operate solenoid coil operated valves.
[0037] Although the invention has been shown and described with respect to a certain embodiment or embodiments, it is obvious that equivalent alterations and modifications will occur to others skilled in the art upon the reading and understanding of this specification and the annexed drawings. In particular regard to the various functions performed by the above described elements (components, assemblies, devices, compositions, etc.), the terms (including a reference to a “means”) used to describe such elements are intended to correspond, unless otherwise indicated, to any element which performs the specified function of the described element (i.e., that is functionally equivalent), even though not structurally equivalent to the disclosed structure which performs the function in the herein illustrated exemplary embodiment or embodiments of the invention. In addition, while a particular feature of the invention may have been described above with respect to only one or more of several illustrated embodiments, such feature may be combined with one or more other features of the other embodiments, as may be desired and advantageous for any given or particular application.
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A piezo-actuated pilot valve that takes advantage of the small compact size and low power requirement of piezo technology to control the pilot flow in a pilot-operated valve. Exemplary piezo-actuated valves can be operated using a relatively low voltage power supply, such as a battery or a solar cell. This enables usage of the valve in remote locations that do not have a ready source of utility-supplied electrical power. The piezo-actuated pilot valve also can have a programmable controller and/or can have an antenna that allows the valve to be controlled wirelessly.
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This application is a divisional of prior application Ser. No. 09/902,622 filed Jul. 12, 2001, which is a continuation of application Ser. No. 08/974,163 filed Nov. 19, 1997, now abandoned, which is a divisional of application Serial No. 08/421,440 filed Apr. 13, 1995, now abandoned.
BACKGROUND OF THE INVENTION
The present invention relates to a drive circuit of an active matrix type display device which is composed of thin-film transistors. In particular, the invention relates to a drive circuit of an active matrix type display device in which source followers are used as analog buffers and variations of their characteristics are suppressed.
The active matrix type display device is a display device in which pixels are arranged at intersections of a matrix with every pixel associated with a switching element, and image information is controlled by turning on/off of the switching elements. This type of display device uses, as a display medium, a liquid crystal, plasma, or some other material or state whose optical characteristic (reflectance, refractive index, transmittance, luminous intensity, or the like) can be varied electrically. In the present invention, specifically a field-effect transistor (three-terminal element) having the gate, source and drain is used as the switching element.
In the following description of the invention, a row of a matrix means a structure in which a signal line (gate line) that is disposed parallel with the row concerned is connected to the gate electrodes of transistors of the row concerned. A column means a structure in which a signal line (source line) that is disposed parallel with the column concerned is connected to the source (or drain) electrodes of transistors of the column concerned. A circuit for driving the gate lines is called a gate drive circuit, and a circuit for driving the source lines is called a source drive circuit.
In the gate drive circuit, stages of a shift register corresponding to the number of gate lines in the vertical direction are arranged linearly and interconnected in series to generate signals of vertical scanning timings of the active matrix type display device. In this manner, the thin-film transistors of the active matrix type display device are switched by means of the gate drive circuit.
In the source drive circuit, stages of a shift register corresponding to the number of source lines in the horizontal direction are arranged linearly and interconnected in series to generate horizontal image data of display image data of the active matrix display device. Analog switches are turned on/off by latch pulses that are synchronized with horizontal scanning signals. In this manner, currents are supplied to the thin-film transistors of the active matrix type display device by means of the source drive circuit, to control orientations of liquid crystal cells.
FIG. 9 schematically shows a conventional active matrix type display device. There are two kinds of polycrystalline silicon thin-film transistor manufacturing processes: a high-temperature process and a low-temperature process. In the high-temperature process, polycrystalline silicon is deposited on an insulating film that is formed on a quartz substrate, and a thermally oxidized SiO 2 is formed as a gate insulating film. Thereafter, gate electrodes are formed, N-type or P-type ions are implanted, and source and drain electrodes are formed. Thus, polycrystalline silicon thin-film transistors are manufactured.
In the low-temperature process, silicon is crystallized by two kinds of methods: solid-phase growth and laser annealing. In the solid-phase growth, a polycrystalline silicon film is obtained by subjecting an amorphous silicon film on an insulating film that is formed on a glass substrate to a heat treatment of 600° C. and 20 hours, for example. In the laser annealing, a polycrystalline silicon film is obtained by applying laser light to amorphous silicon on a glass substrate surface to thereby heat-treat only the film surface portion at a high temperature.
In general, crystalline films are obtained by using one or both of the above two methods.
An SiO 2 film is then formed as a gate insulating film by plasma CVD. Thereafter, gate electrodes are formed, N-type or P-type ions are implanted, and source and drain electrodes are formed. Thus, polycrystalline silicon thin-film transistors are manufactured.
The source drive circuit is a circuit for supplying image data to an active matrix panel of the active matrix type display device by scanning it vertically, and is composed of a shift register, analog switches that are thin-film transistors, analog memories that are capacitors, and analog buffers formed of thin-film transistors.
The analog buffer is needed because the analog memory cannot directly drive the thin-film transistors of the active matrix type display device due to a large load capacitance of the source line.
The thin-film transistor of the analog buffer has a source follower configuration. As shown in FIGS. 6A and 6B , a single thin-film transistor is provided for each data holding control signal line, and the thin-film transistors are so manufactured as to be arranged at regular intervals.
FIG. 6A shows an example of using N-channel thin-film transistors. Alternatively, P-channel thin-film transistors (see FIG. 6 b ) or both types of transistors may be used.
The analog buffers that constitute the source drive circuit of the conventional active matrix type display device have the following problem.
Each analog buffer has the single thin-film transistor that has a source follower configuration. When laser annealing is employed as a means for crystallization as described above in the thin-film transistor manufacturing process, a silicon film on a glass substrate is irradiated with band-like laser light of a width L while being scanned with it in the X-axis direction, i.e., horizontally (see FIG. 7A ) to crystallize silicon, because there exists no such large-diameter laser device as can irradiate a large-size substrate at one time.
When the illumination is effected while the laser light is moved in the X-direction at a constant length at a time, there occurs an overlap of illumination. Since the width L of the band-like laser light does not necessarily coincide with a pitch d (see FIG. 7B ) of the source follower, the illumination laser light quantity varies depending on the position on the silicon film in the laser crystallization step.
Therefore, a positional variation, i.e., variations in characteristics occur in thin-film transistors that are produced from the above silicon film, and the threshold voltage V th varies from one thin-film transistor to another in the range of V thL to V thH depending on the position X on the X-axis (see FIG. 8 ). The threshold voltage V th has a small value at a position where laser beams overlap with each other, and has a large value where they do not. As a result, there occurs a variation in magnitude of output voltages of the source followers, which directly results in a variation of application voltages to the liquid crystal device.
FIG. 11 shows an application voltage vs. transmittance characteristic of a normally-white liquid crystal device. It is understood that a variation ΔV th of the threshold voltage V th causes a corresponding variation of the transmittance, which is reflected in a displayed image.
As described above, the output voltages of the source drive circuit undesirably vary depending on positions thereof, resulting in display unevenness of pixels of the active matrix type display device.
SUMMARY OF THE INVENTION
An object of the present invention is to reduce display unevenness of pixels in an active matrix type display device.
In contrast to the conventional device in which a single analog buffer is provided for a data holding control signal for each data line, the present invention is characterized in that a data holding control signal is connected with a plurality of source followers that are connected together in parallel. Further, in accordance with a preferred embodiment of the present invention, the parallel-connected source followers are a combination of at least one source follower that is irradiated with laser light and at least one source follower that is irradiated twice for crystallization.
A width L of the laser light illumination for crystallization is preferably larger than a pitch d of the source followers, and is equal to the pitch d multiplied by an integer n that is not less than 3. Further, the invention is characterized in that 2 to n−1 source followers are connected together in parallel. A variation of the threshold voltage of thin-film transistors can be suppressed by combining source followers that are illuminated at different numbers of times.
Although the pitch of the source followers and the width of laser light illumination have been mentioned above, the term “pitch of the source followers” may be replaced by another term “pitch of pixels” because they are equal to each other in general.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a circuit diagram showing analog buffers of an active matrix type display device according to a first embodiment of the present invention;
FIG. 2 is a circuit diagram showing analog buffers of an active matrix type display device according to a second embodiment of the invention;
FIG. 3 is a circuit diagram showing analog buffers of an active matrix type display device according to a third embodiment of the invention;
FIG. 4 is a circuit diagram showing analog buffers of an active matrix type display device according to a fourth embodiment of the invention;
FIG. 5 is a circuit diagram showing analog buffers of an active matrix type display device according to a fifth embodiment of the invention;
FIGS. 6A and 6B are circuit diagrams showing examples of analog buffers used in a conventional active matrix type display device;
FIGS. 7A and 7B schematically illustrate laser light illumination in a conventional analog buffer manufacturing step;
FIG. 8 is a graph showing a relationship between the threshold voltage V th of thin-film transistors used in the conventional analog buffers and the laser light illumination position X in a thin-film transistor manufacturing process;
FIG. 9 schematically shows the conventional active matrix type display device;
FIGS. 10A-10F shows a manufacturing process of a complementary inverter circuit; and
FIG. 11 is a graph showing an application voltage vs. transmittance characteristic of a normally-white liquid crystal device.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
First, referring to FIGS. 10A-10F , a description will be made with respect to a manufacturing process of thin-film transistors used in the present invention.
A complementary inverter circuit will be described by way of embodiment. A silicon dioxide film of 1,000-3,000 Å in thickness was formed as an undercoat oxide film on a glass substrate (low-alkali glass, quartz glass, or the like; for instance Corning 7059) by sputtering in an oxygen atmosphere. To improve the productivity, there may be used a film obtained by decomposing and depositing TEOS by plasma CVD.
Then, an amorphous silicon film was deposited at a thickness of 300-5,000 Å, preferably 500-1,000 Å by plasma CVD or LPCVD, and crystallized by being left in a reducing atmosphere of 550° C. to 600° C. for 4-48 hours. The degree of crystallization was increased by performing laser light illumination (wavelength: 308 or 248 nm) after the above step. The silicon film thus crystallized was patterned into island-like regions 1 and 2. A silicon dioxide film 3 of 700-1,500 Å in thickness was formed thereon by sputtering.
Subsequently, a film of aluminum (containing Si of 1 wt % or Sc of 0.1-0.3 wt %) of 1,000 Å to 3 μm was formed by electron beam evaporation or sputtering. A photoresist (for instance, OFPR800/30 cp produced by Tokyo Ohka Kogyo Co., Ltd.) was then formed by spin coating. Formation of an aluminum oxide film of 100-1,000 Å in thickness by anodic oxidation before the formation of the photoresist was effective in providing good adhesiveness with the photoresist and in forming a porous anodic oxide film only on the side faces in a subsequent anodic oxidation step by suppressing a leak current from the photoresist. The photoresist and the aluminum film were patterned, i.e., etched together to form gate electrodes 4 and 5 and mask films 6 and 7 (see FIG. 10 A).
Anodic oxidation was performed on the resulting structure by supplying it with a current in an electrolyte, to form anodic oxide films 8 and 9 of 3,000-6,000 Å, for instance, 5,000 Å in thickness. The anodic oxidation may be performed such that a 3% to 20% acid aqueous solution of citric acid, oxalic acid, phosphoric acid, chromic acid, sulfuric acid, or the like is used and a constant voltage of 10-30 V is applied to the gate electrodes. In this embodiment, the anodic oxidation was performed for 20-40 minutes in oxalic acid of 30° C. by applying a voltage of 10 V. The thickness of the anodic oxide films 8 and 9 was controlled by the anodic oxidation time (see FIG. 10 B).
After removing the mask films 6 and 7 , the gate electrodes 4 and 5 were again supplied with a current in an electrolyte. An ethylene glycol solution containing tartaric acid, boric acid and nitric acid (3% to 10% in total) was used this time. A superior oxide film was obtained when the temperature of the solution was about 10° C., i.e., lower than the room temperature. As a result, barrier type anodic oxide films 10 and 11 were formed on the top and side faces of the gate electrodes 4 and 5 . The thickness of the anodic oxide films 10 and 11 was proportional to the application voltage. For instance, a 2,000-Å-thick anodic oxide film was formed with an application voltage of 150 V. The thickness of the anodic oxide films 10 and 11 was determined by a necessary offset. It is preferred that the thickness be less than 3,000 Å, because a high voltage of more than 250 V is needed to produce an anodic oxide film thicker than 3,000 Å and will cause adverse effects on characteristics of the thin-film transistors. In this embodiment, the voltage was increased to 80-150 V, and a proper voltage was selected depending on a necessary thickness of the anodic oxide films 10 and 11 .
It should be noted that the barrier-type anodic oxide films 10 and 11 were formed between the porous anodic oxide films 8 and 9 and the gate electrodes 4 and 5 rather than outside the porous anodic oxide films 8 and 9 , though the step of forming the barrier-type anodic oxide films 10 and 11 was performed later.
Then, the insulating film 3 was etched by dry etching (or wet etching). The etching depth may be determined arbitrarily; that is, the etching may be performed until the underlying active layers 1 and 2 are exposed, or may stopped halfway. In terms of the productivity, yield and uniformess, it is desirable that the etching be performed until reaching the active layers 1 and 2 . In this case, insulating films 12 and 13 having the original thickness are left in the portions of the insulating film (gate insulating film 3 ) covered with the anodic oxide films 8 and 9 or the gate electrodes 4 and 5 (see FIG. 10 C).
Then, the anodic oxide films 8 and 9 were removed. It is preferred that the etchant be a phosphoric acid type solution, for instance, a mixed acid of phosphoric acid, acetic acid and nitric acid. With a phosphoric acid type etchant, the porous anodic oxide films 8 and 9 are etched at a rate that is more than 10 times faster than the barrier-type anodic oxide films 10 and 11 . Therefore, substantially the barrier-type anodic oxide films 10 and 11 are not etched with a phosphoric acid type etchant. Thus, the gate electrodes inside the barrier-type anodic oxide films were protected.
Sources and drains were formed by implanting accelerated N-type or P-type impurity ions into the active layers 1 and 2 of the above structure. More specifically, first, with the left-hand thin-film transistor region covered with a mask 14 , phosphorus ions of relatively low speed (typical acceleration voltage: 5-30 kV) were introduced by ion doping. In this embodiment, the acceleration voltage was set at 20 kV. Phosphine (PH 3 ) was used as a doping gas. The dose was 5×10 14 to 5×10 15 cm −2 . In this step, phosphorus ions cannot penetrate the insulating film 13 , they were implanted into only the portions of the active region 2 whose surfaces were exposed, to form a drain 15 and a source 16 of the N-channel thin-film transistor (see FIG. 10 D).
Subsequently, phosphorus ions of relatively high speed (typical acceleration voltage: 60-120 kV) were introduced also by ion doping. In this embodiment, the acceleration voltage was 90 kV, and the dose was 1×10 13 to 5×10 14 cm −2 . In this step, phosphorus ions penetrate the insulating film 13 to reach the underlying portions. However, due to the small dose, low-concentration N-channel regions 17 and 18 were formed (see FIG. 10 E).
After completion of the phosphorus doping, the mask 14 was removed. In a manner similar to the above, a source 19 , a drain 20 , and low-concentration P-type regions 21 and 22 were formed in the P-channel thin-film transistor region with the N-channel thin-film transistor region masked this time. Impurity ions introduced into the active regions 1 and 2 were activated by illumination with KrF excimer laser light (wavelength: 248 nm; pulse width: 20 nsec).
Finally, a silicon dioxide film of 3,000-6,000 Å in thickness was formed over the entire surface as an interlayer insulating film 23 by CVD. After contact holes for the sources and drains of the thin-film transistors were formed, aluminum wiring lines and electrodes 24 - 26 were formed. Further, hydrogen annealing was performed at 200° C. to 400° C. Thus, a complementary inverter circuit using the thin-film transistors was completed (see FIG. 10 F).
Although the above description is directed to the inverter circuit, other circuits can be manufactured in similar manners. Further, although the above description is directed to the coplanar thin-film transistors, it can be applied to other types of thin-film transistors such as inverse-stagger type ones.
Embodiments of the invention will be described below.
FIG. 1 shows a first embodiment of the invention. In this embodiment, source followers are arranged at a pitch d, and the laser light illumination width L is equal to 3d. Two source followers are connected to each other in parallel. Representing a source follower matrix by (l, m), the laser light is first applied to source followers (p, q), (p+1, q), (p+2, q),(p, q+1), (p+1, q+1), and (p+2, q+1).
The laser light is then moved so as to illuminate source followers (p+2, q), (p+3, q), (p+4, q), (p+2, q+1), (p+3, q+1), and (p+4, q+1). Actually, after the first laser irradiation, the substrate mounted on a X-Y table is moved and then the second irradiation is carried out.
Further, a next laser irradiation is carried out onto the source followers (p+4, q), (P+5, q), (p+6, q), (p+4, q+1), (P+5, q+1), and (p+6, q+1).
In the above manner, the source followers (p, q), (p, q+1), (p+2, q), (p+2, q+1), (p+4, q), (p+4, q+1), (p+6, q) and (p+6, q+1) are illuminated twice with the laser light. Thus, they have the threshold voltage V thL in view of FIG. 8 .
On the other hand, the source followers (p+1, q), (p+1, q+1), (p+3, q), (p+3, q+1), (p+5, q), and (p+5, q+1) are illuminated only once with the laser light. Thus, they have the threshold voltage V thH .
By connecting to each other in parallel the source followers (p, q) and (p+1, q), the source followers (p+2, q) and (p+3, q), the source followers (p+4, q) and (p+5, q), the source followers (p+1, q+1) and (p+2, q+1), and the source followers (p+3, q+1) and (p+4, q+1) as shown in FIG. 1 , the characteristics of the source followers are averaged, so that variations in the characteristics caused by the laser illumination can be reduced. In other words, in each combined source followers, one source follower has a higher crystallinity TFT while the other one has a lower crystallinity TFT.
FIG. 2 shows a second embodiment of the invention. In this embodiment, source followers are arranged at a pitch d, and the laser light illumination width L is equal to 4d. Three source followers are connected together in parallel.
The laser light is first applied to source followers (p, q), (p+1, q), (p+2, q), (p+3, q), (p, q+1), (p+1, q+1), (p+2, q+1), (p+3, q+1), (p. q+2), (p+1, q+2), (p+2, q+2) and (p+3, q+2).
The laser light is then moved so as to illuminate source followers (p+3, q), (p+4, q), (p+5, q), (p+6, q), (p+3, q+1), (p+4, q+1), (p+5, q+1), (p+6, q+1), (p+3, q+2), (p+4, q+2), (p+5, q+2) and (p+6, q+2).
Since the source followers (p, q), (p, q+1), (p, q+2), (p+3, q), (p+3, q+1), (p+3, q+2), (p+6, q), (p+6, q+1) and (p+6, q+2) are illuminated twice with the laser light, they have the threshold voltage V thL (see FIG. 8 ).
Since the source followers (p+1, q), (p+2, q), (p+1, q+1), (p+2, q+1), (p+1, q+2), (p+2, q+2), (p+4, q), (p+5, q), (p+4, q+1), (p+5, q+1), (p+4, q+2) and (p+5, q+2) are illuminated only once with the laser light, they have the threshold voltage V thH (see FIG. 8 ).
By connecting together in parallel the source followers (p, q), (p+1, q) and (p+2, q), the source followers (p+3, q), (p+4, q) and (p+5, q), the source followers (p+1, q+1), (p+2, q+1) and (p+3, q+1), the source followers (p+4, q+1), (p+5, q+1) and (p+6, q+1), and the source followers (p+2, q+2), (p+3, q+2) and (p+4, q+2), respectively, as shown in FIG. 2 , one of the three source followers of each combination is illuminated twice with the laser light and the other two source followers are illuminated only once. By combining the source followers in the above manner, the source followers of every set are made uniform, so that variations in the characteristics caused by the laser illumination can be eliminated.
FIG. 3 shows a third embodiment of the invention. In this embodiment, source followers are arranged at a pitch d, and the laser light illumination width L is equal to 4d. Two source followers are connected in parallel to form one analog buffer where one source follower of an adjacent buffer is located between the two.
The laser light is first applied to source followers (p, q), (p+1, q), (p+2, q), (p+3, q), (p, q+1), (p+1, q+1), (p+2, q+1) and (p+3, q+1).
The laser light is then moved so as to illuminate source followers (p+3, q), (p+4, q), (p+5, q), (p+6, q), (p+3, q+1), (p+4, q+1), (p+5, q+1) and (p+6, q+1).
Since the source followers (p, q), (p, q+1), (p+3, q), (p+3, q+1), (p+6, q) and (p+6, q+1) are illuminated twice with the laser light, they have the threshold voltage V thL (see FIG. 8 ).
Since the source followers (p+1, q), (p+2, q), (p+1, q+1), (p+2, q+1), (p+4, q), (p+5, q), (p+4, q+1) and (p+5, q+1) are illuminated only once with the laser light, they have the threshold voltage V thH (see FIG. 8 ).
By connecting to each other in parallel the source followers (p, q) and (p+2, q), the source followers (p+1, q) and (p+3, q), the source followers (p+4, q) and (p+6, q), the source followers (p, q+1) and (p+2, q+1), the source followers (p+1, q+1) and (p+3, q+1), and the source followers (p+4, q+1) and (p+6, q+1) as shown in FIG. 3 , one of the two source followers of each combination is illuminated twice with the laser light and the other source follower is illuminated only once. By combining the source followers in the above manner, the source followers of every set are made uniform, so that variations in the characteristics caused by the laser illumination can be eliminated.
FIG. 4 shows a fourth embodiment of the invention. In this embodiment, source followers are arranged at a pitch d, and the laser light illumination width L is equal to 4d. Two source followers that are located in an oblique direction are connected to each other in parallel.
The laser light is first applied to source followers (p, q), (p+1, q), (p+2, q), (p+3, q), (p, q+1), (p+1, q+1), (p+2, q+1) and (p+3, q+1).
The laser light is then moved so as to illuminate source followers (p+3, q), (p+4, q), (p+5, q), (p+6, q), (p+3, q+1), (p+4, q+1), (p+5, q+1) and (p+6, q+1).
By connecting to each other in parallel the source followers (p, q) and (p+1, q+1), the source followers (p+1, q) and (p+2, q+1), the source followers (p+2, q) and (p+3, q+1), the source followers (p+3, q) and (p+4, q+1), the source followers (p+4, q) and (p+5, q+1), and the source followers (p+5, q) and (p+6, q+1) as shown in FIG. 4 , the characteristics of the source followers are averaged, so that variations in the characteristics caused by the laser illumination can be reduced.
FIG. 5 shows a fifth embodiment of the invention. In this embodiment, source followers are arranged at a pitch d, and the laser light illumination width L is equal to 4d. Three source followers located in an oblique direction are connected together in parallel.
The laser light is first applied to source followers (p, q), (p+1, q), (p+2, q), (p+3, q), (p, q+1), (p+1, q+1), (p+2, q+1), (p+3, q+1), (p, q+2), (p+1, q+2), (p+2, q+2) and (p+3, q+2).
The laser light is then moved so as to illuminate source followers (p+3, q), (p+4, q), (p+5, q), (p+6, q), (p+3, q+1), (p+4, q+1), (p+5, q+1), (p+6, q+1), (p+3, q+2), (p+4, q+2), (p+5, q+2) and (p+6, q+2).
Since the source followers (p, q), (p, q+1), (p, q+2), (p+3, q), (p+3, q+1), (p+3, q+2), (p+6, q), (p+6, q+1) and (p+6, q+2) are illuminated twice with the laser light, they have the threshold voltage V thL (see FIG. 8 ).
Since the source followers (p+1, q), (p+2, q), (p+1, q+1), (p+2, q+1), (p+1, q+2), (p+2, q+2), (p+4, q), (p+5, q), (p+4, q+1), (p+5, q+1), (p+4, q+2) and (p+5, q+2) are illuminated only once with the laser light, they have the threshold voltage V thH (see FIG. 8 ).
By connecting together in parallel the source followers (p, q), (p+1, q+1) and (p+2, q+2), the source followers (p+1, q), (p+2, q+1) and (p+3, q+2), the source followers (p+2, q), (p+3, q+1) and (p+4, q+2), the source followers (p+3, q), (p+4, q+1) and (p+5, q+2), and the source followers (p+4, q), (p+5, q+1) and (p+6, q+2) as shown in FIG. 5 , one of the three source followers of each combination is illuminated twice with the laser light and the other two source followers are illuminated only once. By combining the source followers in the above manner, the source followers of every set are made uniform, so that variations in the characteristics caused by the laser illumination can be eliminated.
As described above, by connecting in parallel the source followers that use thin-film transistors, the invention can suppress a variation of the threshold voltage V th due to overlapping of laser light illumination areas, to thereby reduce display unevenness of pixels.
While preferred embodiments of the present invention has been described, it is to be understood that the present invention should not be limited to those specific embodiments. Various modifications may be made by those ordinary skilled in the art. For example, it is possible to replace the source followers with other elements having an equivalent function, for example, op amp.
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A data holding control signal for each data line is supplied to a plurality of source followers that are connected together in parallel. The parallel-connected source followers are a combination of at least one first follower that is illuminated with laser light only once and at least one second follower that is illuminated twice. A width of the laser light illumination for crystallization is equal to a pitch of the source followers multiplied by an integer that is not less than 3.
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TECHNICAL FIELD
[0001] This invention relates to electrical switching devices and more particularly to the architecture and construction of flexible switching devices and the use thereof in switching and proportional control of electric/electronic currents.
[0002] The working components of these devices can appear as and perform similarly to conventional textile materials and thus have applications as user-interfaces (including pressure sensors) particularly in the field of textile/wearable electronics. The devices are applicable as alternatives to ‘hard’ electronic user-interfaces. Generally the devices can be produced using commercial textile manufacturing processes but the invention is not limited to such processes.
[0003] In this specification:
[0004] ‘textile’ includes any assemblage of fibres, including spun, monofil and multifilament, for example woven, non-woven, felted or tufted; and the fibres present may be natural, semi-synthetic, synthetic, blends thereof and metals and alloys;
[0005] ‘electronic’ includes ‘low’ currents as in electronic circuits and ‘high’ currents as in circuits commonly referred as ‘electric’;
[0006] ‘user interface’ includes any system in which a mechanical action is registered as a change in electrical resistance or conductance. The mechanical action may be for example conscious bodily action such as finger pressure or footfall, animal movement, pathological bodily movement, expansion or contraction due to bodily or inanimate temperature variation, displacement in civil engineering structures.
[0007] ‘mechanical deformation’ includes pressure, stretching and bending and combinations of these.
SUMMARY OF THE INVENTION
[0008] The invention provides an electronic resistor user-interface comprising flexible conductive materials and a flexible variable resistive element capable of exhibiting a change in electrical resistance on mechanical deformation, characterised by textile-form electrodes, a textile-form variably resistive element and textile-form members connective to external circuitry.
[0009] It will be appreciated that the textile form of each component of the user-interface may be provided individually or by sharing with a neighbouring component.
[0010] The electrodes, providing a conductive pathway to and from either side of the variably resistive element, generally conductive fabrics (these may be knitted, woven or non-woven), yarns, fibres, coated fabrics or printed fabrics or printed fabrics, composed wholly or partly of conductive materials such as metals, metal oxides, or semi-conductive materials such as conductive polymers (polyaniline, polypyrrole and polythiophenes) or carbon. Materials used for coating or printing conductive layers onto fabrics may include inks or polymers containing metals, metal oxides or semi-conductive materials such as conductive polymers or carbon. Preferred electrodes comprise stainless steel fibres, monofil and multifilament or stable conducting polymers, to provide durability under textile cleaning conditions.
[0011] The electrodes can be supported by non-conducting textile, preferably of area extending outside that of the electrodes, to support also connective members to be described.
[0012] Methods to produce the required electrical contact of the electrode with the variably resistive element include one or more of the following:
a) conductive yarns may be woven, knitted, embroidered in selected areas of the support so as to produce conductive pathways or isolated conductive regions or circuits; b) conductive fabrics may be sewn or bonded onto the support; c) conductive coatings or printing inks may be laid down onto the support by techniques such as spraying, screen printing, digital printing, direct coating, transfer coating, sputter coating, vapour phase deposition, powder coating and surface polymerisation.
[0016] Printing is preferred, if appropriate using techniques such as resist, to produce contact patterns at many levels of complexity and for repetition manufacture.
[0017] The extension of the support outside the electrode region is sufficient to accommodate the connective members to be described. It may be relatively small, to give a unit complete in itself and applicable to a user-apparatus such as a garment.
[0018] Alternatively it may be part of a user-apparatus, the electrodes and variably resistive element being assembled in situ. It may carry terminals at which the connective members pass the electric current to other conductors.
[0019] The variably resistive element, providing a controllable conductive pathway between the two electrodes, may take a number of forms, for example
a) a self-supporting layer; b) a layer containing continuous or long-staple textile reinforcement; c) a coating applied to the surface of textile eg. as fabrics, yarns or fibres. This coating preferably contains a particulate variably resistive material as described in PCT/GB99/00205, and may contain a polymer binder such as polyurethane, PVC, polyacrylonitrile, silicone, or other elastomer. Alternatively the variably resistive material may be for example a metal oxide, a conductive polymer (such as polyaniline, polypyrrole and polythiophenes) or carbon. This coating may be applied for example by commercial methods such as direct coating, transfer coating, printing, padding or spraying; d) it may contain fibres that are inherently electrically conductive or are extruded to contain a variably resistive material as described in PCT/GB99/00205; e) it may be incorporated into or coated onto one of the electrodes in order to simplify manufacturing processes or increase durability in certain cases.
[0025] The variable resistor generally comprises a polymer and a particulate electrically conductive material. That material may be present in one or more of the following states:
a) a constituent of the base structure of the element; b) particles trapped in interstices and/or adhering to surfaces; c) a surface phase formed by interaction of conductive particles (i or ii below) with the base structure of the element or a coating thereon.
[0029] Whichever state the conductive material of the variably resistive element is present in, it may be introduced:
i) ‘naked’, that is, without pre-coat but possibly carrying on its surface the residue of a surface phase in equilibrium with its storage atmosphere or formed during incorporation into the element. This is clearly practicable for states a) and c), but possibly leads to a less physically stable element in stage b); ii) lightly coated, that is, carrying a thin coating of a passivating or water-displacing material or the residue of such coating formed during incorporation into the element. This is similar to i) but may afford better controllability in manufacture; iii) polymer-coated but conductive when undeformed.
[0033] This is exemplified by granular nickel/polymer compositions of so high nickel content that the physical properties of the polymer are weakly if at all discernible. As an example, for nickel starting particles of bulk density 0.85 to 0.95 this corresponds to a nickel/silicone volume ratio (tapped bulk:voidless solid) typically over about 100. Material of form iii) can be applied in aqueous suspension. The polymer may or may not be an elastomer. Form iii) also affords better controllability in manufacture than i).
iv) Polymer-coated but conductive only when deformed. This is exemplified by nickel/polymer compositions of nickel content lower than for iii), low enough for physical properties of the polymer to be discernible, and high enough that during mixing the nickel particles and liquid form polymer become resolved into granules rather than forming a bulk phase. This is preferred for b) an may be unnecessary for a) and c). It is preferred for the present invention: more details are given in co-pending application PCT/GB99/00205. An alternative would be to use particles made by comminuting materials as in v) below. Unlike i) to iii), material iv) can afford a response to deformation within each individual granule as well as between granules, but ground material v) is less sensitive. In making the element, material iv) can be applied in aqueous suspension; v) Embedded in bulk phase polymer. This relates to a) and c) only. There is response to deformation within the bulk phase as well as between textile fibres.
The general definition of the preferred variably resistive material exemplified by iv) and v) above is that it exhibits quantum tunnelling conductance (‘QTC’) when deformed. This is a property of polymer compositions in which a filler selected from powder-form metals or alloys, electrically conductive oxides of said elements and alloys, and mixtures thereof are in admixture with a non-conductive elastomer, having been mixed in a controlled manner whereby the filler is dispersed within the elastomer and remains structurally intact and the voids present in the starting filler powder become infilled with elastomer and particles of filler become set in close proximity during curing of the elastomer.
[0036] The connective textile member providing a highly flexible and durable electrically conductive pathway to and from each electrode may for example comprise conductive tracks in the non-conducting textile support fabric, ribbon or tape. The conductive tracks may be formed using electrically conductive yarns which may be woven, knitted, sewn or embroidered onto or into the non-conducting textile support. As in the construction of the electrodes, stainless steel fibres, monofil and multifilament are convenient as conductive yarns. The conductive tracks may also be printed onto the non-conducting textile support. In certain cases the conductive tracks may need to be insulated to avoid short circuits and this can be achieved by for example coating with a flexible polymer, encapsulating in a non-conducting textile cover or isolating during the weaving process. Alternatively the yarns may be spun with a conductive core and non-conducting outer sheath. In another alternative at least one connective member comprises variably resistive material pre-stressed to conductance, as described in PCT/GB99/02402.
BRIEF DESCRIPTION OF THE DRAWINGS
[0037] FIG. 1 shows a basic switch;
[0038] FIG. 2 shows a switch adaptable to multiple external circuits;
[0039] FIG. 3 shows a multiple key device; and
[0040] FIG. 4 shows a position-sensitive switch.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0041] In conjunction with appropriate electronics the devices may be used for digital type switching, analogue switching, proportional control, pressure sensing, flex sensing in the following applications, for example:
[0042] interfaces to electronic apparatus such as:
computers, PDA, personal audio, GPS; domestic appliances, TV/video, computer games, electronic musical instruments, toys lighting and heating, clocks and watches; personal healthcare such as heart rate monitors, disability and mobility aids; automotive user controls; controls for wearable electronics; educational aids; medical applications such as pressure sensitive bandages, dressings, garments, bed pads, sports braces; sport applications such as show sensors, sensors in contact sport (martial arts, boxing, fencing), body armour that can detect and measure hits, blows or strikes, movement detection and measurement in sports garments; seat sensors in any seating application for example auditoria and waiting rooms; garment and shoe fitting; presence sensors, for example under-carpet, in-flooring and in wall coverings.
[0054] Referring to FIG. 1 , the basic textile switch/sensor device comprises two self-supporting textile electrodes 10 , 12 sandwiching variably resistive element 14 made by applying to nylon cloth an aqueous suspension of highly void-bearing granular nickel-in-silicone at volume ratio within the composition of 70:1 capable of quantum tunnelling conduction, as described in PCT/GB99/00205. Electrodes 10 , 12 and element 14 are fixed in intimate contact so as to appear and function as one textile layer. Each electrode 10 , 12 is conductively linked to a connective textile element 16 consisting of stainless steel thread in nylon tape 18 extending from electrodes 10 , 12 . When pressure is applied to any area of electrode 10 , 12 the resistance between them decreases. The resistance between electrodes 10 , 12 will also decrease by bending.
[0055] Referring to FIG. 2 , in a variant of the basic textile switch/sensor, upper layer 20 is a non-conducting textile support under which adheres the upper electrode constituted by discrete electrically conductive sub-area 22 conductively linked to connective member 24 , which is a conductive track in extension 26 of support 20 . Variably resistive element 28 , similar to that of element 12 above but containing polyurethane binder, is provided as a coating on lower electrode 29 , the area of which is greater than that of upper electrode 22 . Lower electrode 29 is formed with lower connective member 24 , a conductive track on an extension 26 of electrode 29 . When pressure is applied to sub-are a 22 , the resistance between elements 22 and 29 changes. Effectively this defines a single switching or pressure sensitive area 22 in upper layer 20 .
[0056] Referring to FIG. 3 , a multiple key textile switch/sensor device is similar in form to that shown in FIG. 2 except that under upper layer 30 are adhered three discrete electrodes constituted by electrically conductive sub-areas 32 , 34 and 36 isolated from each other by the non-conducting textile support and electrically linkable to external circuitry by way of connective members 33 , 35 , 37 respectively, which are conductive tracks on extension 31 of layer 30 . Variably resistive element 38 is provided as a coating on lower electrode 39 ; it is of the type decreasing in resistance when mechanically deformed, since it depends on low or zero conductivity in the plane of element 38 . Electrical connection to lower electrode 39 is by means of conductor 24 and extension 26 , as in FIG. 2 . When pressure is applied to any of areas overlying electrodes 32 , 34 and 36 , the resistance between the relevant electrode(s) and lower electrode 39 decreases. Effectively this defines three separate switching or pressure sensitive areas 32 , 34 and 36 , suitable as individual keys in a textile keypad or individual pressure sensors in a textile sensor pad. If the sensor is to respond to bending, other electrodes in contact with lower layer 39 would be provided to measure changes in conductivity in the plane of that layer; at the same time the external circuit would temporarily switch out the measurement perpendicular to the plane of layer 39 .
[0057] Referring to FIG. 4 , in a matrix switch/sensor device the upper layer 40 and lower layer 42 each contains parallel linear electrodes consisting of isolated rows 44 and columns 46 of conductive areas woven into a non-conducting textile support. Conductive areas 44 , 46 are warp yarns that have been woven between non-conductive yarns. Variably resistive element 48 is a sheet of fabric carrying nickel/silicone QTC granules as in FIG. 1 applied by padding with an aqueous dispersion of the granules, which are of the type decreasing in resistance on mechanical deformation. Layer 48 is supported between layers 40 and 42 and coincides in area with electrodes 44 and 46 . When pressure is applied to a localised area of 40 or 42 there is a decrease in resistance at the junctions of the conductive rows 44 and columns 46 which fall within the localised area of applied pressure. This device can be used as a pressure map to locate force applied within the area of the textile electrodes. By defining areas of the textile electrodes as keys, this device can also be used as a multi-key keypad.
EXAMPLE
[0058] One electrode is a fabric consisting of a 20 g/m2 knitted mesh containing metallised nylon yarns. The variably resistive element was applied to this fabric by transfer coating of:
[0059] 75% w/w water based polyurethane (Impranil-Dow chemical); and
[0060] 27% w/w nickel/silicone QTC granules (size 45-70 micrometres)
[0061] and was cured on the fabric at 110 C. The other textile electrode element is another piece of the same knitted mesh. Each electrode was then sewn onto a non-conducting support fabric sheet of greater area than the electrode. The sensor was assembled with the coated side of the first electrode element facing the second electrode. Separate connective textile elements each consisting of metallised nylon thread were sewn up to each electrode so that good electrical contact was made with each. On the non-conducting support fabric outside the electrodes two metal textile press-studs were fixed such that each was in contact with the two conductive yarn tails. An electrical circuit was then connected to the press-studs so that a sensor circuit was completed.
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An electronic resistor user interface comprises flexible conductive materials and a flexible variably resistive element capable of exhibiting a change in electrical resistance on mechanical deformation and is characterised by textile-form electrodes ( 10,12 ), a textile form variably resistive element ( 14 ) and textile-form members ( 16 ) connective to external circuitry.
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FIELD OF THE INVENTION
The present invention relates generally to a wide panel seaming method and apparatus for forming EPDM roofing membrane. More particularly, the present invention relates to a method and apparatus for continuously seaming cured stock wide panels of EPDM membrane to form a composite EPDM roofing membrane of predetermined width and indefinite length.
BACKGROUND OF THE INVENTION
EPDM is used as a single ply roofing membrane material for covering industrial and commercial flat roofs. EPDM roofing membrane having a thickness between {fraction (1/16)} inch and {fraction (3/32)} inch has been found to constitute an extremely useful waterproof roofing material, particularly for industrial and commercial buildings having relatively flat roofs of very large size. Such membranes are generally applied to the roof surface in a vulcanized or cured state. Because of outstanding weathering resistance and flexibility, cured EPDM based roofing membrane has rapidly gained acceptance. Notwithstanding the wide acceptance of EPDM based roofing membrane, a disadvantage of utilizing these elastomers is the lack of adhesion of EPDM, especially cured EPDM, to itself. Application of cured EPDM roofing membrane is typically highly labor intensive because, in applying sheets of EPDM roofing membrane to a roof, it is usually necessary to splice cured sheets of EPDM roofing membrane together.
Typically, the roofing material comes in rolls and is rolled on in strips running the length of the building with a slight overlap between adjacent strips to provide a lap joint. Unfortunately, in the past such roofing material has typically been available only in rolls of relatively narrow width, for example, four feet wide. For a roof of large dimensions, such as 200 feet by 400 feet, the time required to apply the roofing material strips of narrow width becomes excessive and, in light of today's high labor casts, relatively expensive. To reduce the application time, and hence the cost, of roofing with EPDM sheet stock, it is desirable to provide the sheet stock in rolls of very large width, such as forty feet or more wide. With sheet stock of such width, a roof measuring 200 feet by 400 feet can be applied in five 40-foot by 200-foot strips. The time required to roof a building in this manner is a mere fraction, of that previously necessary with sheet stock of narrower width, e.g., 4 feet wide. This invention relates to a method and apparatus for providing indefinite length stock of very large width synthetic rubber sheeting, e.g., EPDM membrane, from indefinite length stock of relatively narrower width.
Accordingly, it is an object of this invention to provide indefinite length sheet stock of synthetic rubber of extremely large width, e.g., forty feet or more. This object has been accomplished in accordance with certain of the principles of this invention by providing means to feed out in a horizontal direction from a feed roll or the like, a plurality of rolls of stock synthetic rubber roofing, the length being equal to the length of the desired final stock and the width being equal to the combined width of the rolls.
SUMMARY OF THE INVENTION
Briefly, according to the present invention there is provided a method of continuously seaming cured wide panels of EPDM membrane to form a composite sheet of predetermined width and indefinite length. The method includes the steps of providing at least two rolls of wide panels of cured EPDM membrane having longitudinal marginal edges and feeding the wide panels of cured EPDM roofing membranes from the at least two rolls of stock roofing membrane in a first direction. The longitudinal marginal edges of the wide panels of cured EPDM membranes are positioned in an overlapping relationship as the wide panels of cured EPDM membranes are fed in the first direction and then the overlapping longitudinal marginal edges are continuously seamed to form a composite sheet of EPDM roofing membrane of indefinite length.
The apparatus for continuously seaming wide panels of cured EPDM membrane to form a composite roofing membrane of predetermined width and indefinite length includes at least two supply stations, a seaming station and a storage station. The at least two supply stations supply and simultaneously position indefinite length stock of wide panel cured EPDM membrane in an overlapping relationship. The seaming station continuously seams the overlapping cured EPDM membranes to form a composite roofing membrane of predetermined width and indefinite length and the storage station continuously reels the composite roofing membrane for storage.
DESCRIPTION OF THE DRAWINGS
These and other features, advantages, and objectives of the invention will become more readily apparent from a detailed description thereof taken in conjunction with the drawings in which:
FIG. 1 is a perspective view of three rolls of overlapping cured stock wide panels of EPDM roofing membrane containing an adhesive along the top marginal edge;
FIG. 2 is a perspective view of three rolls of overlapping adhesive free cured stock wide panels of EPDM roofing membrane;
FIG. 3 is a perspective view of an apparatus for seaming wide panels of EPDM membrane in accordance with one aspect of the present invention;
FIG. 4 is an enlarged partial perspective view of a seaming station of the apparatus of FIG. 3;
FIG. 5 is a cross-sectional view of the seaming station of the apparatus of FIG. 3 for applying adhesive between the wide panels of EPDM membrane;
FIG. 6 is a cross-sectional view of the apparatus of FIG. 3; and
FIG. 7 is a cross-sectional view of an alternate embodiment of an apparatus for seaming wide panels of EPDM membrane in accordance with another aspect of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings wherein like reference characters represent like elements there is shown an apparatus 10 for forming a composite roofing membrane 12 of cured EPDM membrane 14 . The apparatus 10 of the present invention is designed to form an indefinite length composite roofing membrane 12 of predetermined width, for example, 100 feet, from an indefinite length panel of much smaller width, e.g., 10 feet. A 100 foot wide roll of composite roofing membrane 12 is more convenient and useful in covering very large surfaces such as the roof of a large building. The time required to cover a large roof with conventional roofing membrane of relatively narrower width is many times that required to cover the same roof with composite roofing membrane formed in accordance with the present invention.
Referring to the figures, an apparatus 10 for forming an indefinite length composite roofing membrane 12 is shown. The apparatus 10 includes at least two supply stations 16 which supply indefinite length stock of wide panel cured EPDM membrane 14 or other similar olefin type polymers (FIGS. 3, 6 and 7 ). The term “EPDM” is intended to mean a terpolymer of ethylene, propylene and a diene monomer.
In one embodiment, at least one marginal edge 18 of the cured EPDM membrane 14 includes a preapplied adhesive 20 (FIG. 1 ). The adhesive 20 may be a thermoplastic elastomer (TPE), thermoplastic polyolefin (TPO) or suitable thermoplastic adhesive of a type well known in the art. The term “thermoplastic elastomer” refers to an elastomer that can be melt-processed (as contrasted with conventional cross-linked rubbers). The term “thermoplastic polyolefin” refers to uncrosslinked polyolefins that are thermoplastic. The thermoplastic polyolefins are made by blending ethylene-propylene polymers with polypropylene. The ethylene-propylene polymers may be blended with polypropylene by conventional mixing techniques. In an alternate embodiment, ethylene-propylene and polypropylene are made in a reactor simultaneously creating a homogenous mixture. The polymer is formulated with stabilizers, pigments and antioxidants to obtain the appropriate adhesive properties. Preferred TPO's include ethylene-propylene rubber blended with polypropylene. The TPE's and TPO's can be applied using conventional plastic techniques, such as extrusion and the like. In yet another embodiment, the cured EPDM membrane 14 is free of adhesive (FIG. 2 ).
The supply station 16 includes a supply roll 22 containing cured EPDM membrane 14 of indefinite length and selected width wound on a horizontal mandrel. The mandrel is suitably journaled for rotation about its respective horizontal axis. The supply station 16 also includes a tensioning device 24 to maintain a constant tension on the cured EPDM membrane 14 as the membrane is fed from the supply roll 22 to a storage roll 26 . In a preferred embodiment, the tensioning device 24 includes an array of rollers suitably supported for rotation about their respective longitudinal axes. As shown in FIG. 3, the tensioning device 24 includes a support roll 28 that supports the cured EPDM membrane 14 as the membrane is fed from the supply roll 22 and a tensioning roll 30 pivotally connected to maintain a downward pressure on the cured EPDM membrane between the supply roll and the support roll.
The supply station 16 feeds out a selected length of cured EPDM membrane 14 in the direction of the seaming station 32 . As shown in FIGS. 1-3, the supply stations 16 are arranged in an overlapping manner to facilitate the overlapping of cured EPDM membrane. The supply stations 16 may be arranged in an alternating overlapping arrangement (FIG. 3) or in a step-wise arrangement (FIGS. 1 and 2 ).
The seaming station 32 , FIGS. 3-7, includes a frame member 34 supporting a press assembly 36 and a device 38 for seaming the overlapping cured EPDM membranes 14 . In a preferred embodiment, the press assembly 36 includes pinch rollers 40 and 40 a suitably supported for rotation about their respective longitudinal axes. As the overlapping edges of the cured EPDM membranes 14 pass between pinch rollers 40 and 40 a , the opposing pinch rollers compress the overlapping edges thereby securing the membranes together to form a seam and enhancing the permanency of the seam. It will be appreciated that the overlapping edges of the cured EPDM membranes 14 may be compressed using most any suitable apparatus as well known in the art.
In one embodiment as shown in FIG. 7, the device 38 for seaming the overlapping cured EPDM membranes 14 includes a plurality of hot air guns 42 of a type well known in the roofing membrane art. It will be appreciated that a hot air gun 42 is used to operatively seam a roofing membrane specially manufactured to include a preapplied adhesive of the type described above to an opposing roofing membrane. The hot air gun 42 is operatively attached to the frame member 34 above the overlapping edges and directed at the overlapping edges to heat the area of overlap to weld the overlapping cured EPDM membranes together and form a seam.
In yet another embodiment as shown in FIGS. 3-6, wherein the cured EPDM roofing membrane does not contain a preapplied adhesive, the device 38 for seaming the overlapping cured EPDM membranes 14 includes an adhesive applicator 44 which applies adhesive to the marginal edge region of the upper surface of a lower wide panel of cured EPDM membrane and/or to the marginal edge region of the bottom surface of the upper wide panel of cured EPDM membrane as it is fed through the adhesive applicator. Any commercially available hot melt adhesive applicator 44 , such as available from Norton or Pyles, can be utilized. The adhesive applicator 44 may terminate flow of the adhesive from the applicator when the membrane is stopped to avoid undesired accumulation of adhesive on the cured EPDM membrane. The adhesive applicator 44 also prevents adhesive 20 from being dispensed from the applicator when no cured EPDM membrane 14 is present, whether or not the apparatus 10 is actually in operation.
The formed composite roofing membrane 12 from the seaming station 32 is then conveyed to a storage station 46 (FIGS. 6 and 7 ). The storage station 46 includes a rotatable take-up roll 48 onto which the composite roofing membrane 12 is rolled for storage purposes. Following reeling of the composite roofing membrane 12 on the take-up roll 48 at the storage station 46 , the take-up roll 48 is transported for use on a roof deck or for storage and later application to a roof deck as described above. The take-up roll 48 is motor-driven to convey the cured EPDM membrane 14 from the supply roll 22 to the storage roll 28 . The speed and operation of the take-up roll 48 is controlled from a control panel.
The composite roofing membrane 12 may be cut to a desired length by a roofing membrane cutter (not shown) of a type well known in the art. The cutter may be used to cut transversely across the fed-out composite roofing membrane 12 when a desired length has been fed past the seaming station 32 for the purpose of providing a cut sheet of desired length and width.
It will be appreciated that an important aspect of this invention inheres in the fact that any number of wide panel cured EPDM membranes 14 may be continuously joined together to form one large composite EPDM roofing membrane 12 . Furthermore, a plurality of wider panel cured EPDM membranes may be joined simultaneously on the apparatus 10 to form separate larger composite EPDM roofing membranes.
The documents and patents described herein are hereby incorporated by reference.
Having described presently preferred embodiments of the present invention, the invention may be otherwise embodies within the scope of the appended claims.
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A method and apparatus for continuously seaming cured EPDM membrane to form a composite sheet of predetermined width and indefinite length. The method includes the steps of providing at least two rolls of cured EPDM membrane having longitudinal marginal edges and feeding the cured EPDM membrane from the at least two rolls in a first direction. The longitudinal marginal edges of the cured EPDM membranes are positioned in an overlapping relationship as the cured EPDM membranes are fed in the first direction and then the overlapping longitudinal marginal edges are continuously seamed to form a composite sheet of indefinite length.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation Ser. No. 427,139, filed Sept. 29, 1982 now U.S. Pat. No. 4,440,952, which is a continuation-in-part of application Ser. No. 403,289, filed July 30, 1982, which is a continuation-in-part of application Ser. No. 397,488, filed July 12, 1982, now abandoned.
BACKGROUND OF THE INVENTION
I. Field of the Invention
This invention relates to catalyzed alkylation of aromatic reactants in general and to monoalkylation of 1-alkyl-diaminobenzenes in particular.
II. Description of the Prior Art
There exists a need for new and varied dialkyl-diaminobenzenes for various uses. Such compounds are used as curing agents for epoxy resins, fuel stabilizers, antioxidants, hair dyes, and more recently as polyurethane chain extenders.
Various prior art alkylation techniques are disclosed in the following patents: U.S. Pat. Nos. 2,814,646; 3,275,690; 3,649,693; 3,678,113; 3,923,892; 4,128,582; and 4,219,502.
SUMMARY OF THE INVENTION
The present invention is directed to providing dialkyl-diaminobenzenes from alkyl-diaminobenzenes. The products have numerous direct uses as well as their utility as versatile intermediates.
The present invention is a process for the monoalkylation of 1-alkyl-2,4-diaminobenzene of structure: ##STR2## or 1-alkyl-2,6-diaminobenzene of structure: ##STR3## where R is a lower alkyl or cycloalkyl, said process comprising the steps of:
(a) reacting a 1-alkyl-2,4-diaminobenzene or a 1-alkyl-2,6-diaminobenzene at elevated temperature and pressure with an alkylene having at least three carbon atoms, in the presence of an aluminum anilide catalyst; and
(b) recovering a monoalkylated product of 1-alkyl-2,4-diaminobenzene or 1-alkyl-2,6-diaminobenzene as the principal product.
The present invention is also a process for the production of 1-methyl-2,4-diamino-5-ispropylbenzene comprising the steps of:
(a) heating about five mole parts 1-methyl-2,4-diaminobenzene, about one mole part aniline, and about one mole part aluminum anilide catalyst with propylene at about 300° C. and about 1,000 psig; and
(b) recovering 1-methyl-2,4-diamino-5-isopropylbenzene.
Alkylenes suitable for the invention include propylene, butylene, pentylene, cyclohexene and the like.
Catalysts suitable for the invention are those containing an active aluminum, preferably organoaluminums. Most preferred is triethylaluminum.
Any 2,4-diamino or 2,6-diamino alkylbenzene is suitable for the invention but the 2,4-diaminos are preferred because they provide a higher conversion. The alkyl substituent may be methyl, ethyl, or other lower alkyl/cycloalkyl substituent. Methyl is especially preferred. Most especially preferred is the reaction of propylene and 1-methyl-2,4-diaminobenzene.
Aniline is an optional ingredient. While Applicant does not fully understand the role of aniline in the reaction, it does provide catalyst stability. It is theorized that the aniline prevents polymerization of the organoaluminum catalyst since in some cases without aniline, the reaction mass becomes too viscous for good catalytic activity and te experiment must be scrapped. Applicant does not intend to be bound by this theory.
The present inventive process is carried out in the presence of an aluminum anilide-type catalyst. Aluminum anilide-type catalysts useful in the process include those used to ortho alkylate amines as described in U.S. Pat. Nos. 2,814,646; 3,275,690; 3,923,892; and 4,128,582. The aluminum anilides are readily prepared by reacting aluminum, aluminum hydride, aluminum alkyl halide, or preferably aluminum trialkyls such as the tri-lower alkyls including triethyl aluminum and trimethyl aluminum. This can be carried out by adding the aluminum or aluminum compound to aromatic amine and heating in a nitrogen atmosphere unitl an exothermic reaction occurs. This is preferably conducted in an autoclave which can withstand 1,000 psig pressure. Suitable aluminum alkyl halides include diethyl aluminum chloride, methyl aluminum sesquichloride, and the like When aluminum alkyls are used to prepare the catalyst care should be taken in handling these pyrophoric materials. The alkyls react with aromatic amines at fairly low temperatures, about ambient to 150° C. Aluminum metal generally requires a little higher temperature, about 200° C. or more. Catalyst formation, once initiated, proceeds rapidly.
The aluminum anilide-type catalysts also include combinations of the above with Friedel-Crafts promoters such as aluminum chloride or hydrogen halide promoters. Of the latter, hydrogen chloride is preferred. An amount sufficient to provide about 0.1-2.0 gram atoms chloride per gram atom aluminum is a useful ratio. The hydrogen halide is merely added to the aluminum anilide catalyst.
The amount of aluminum anilide-type catalyst used can vary over a wide range. A useful range is that amount which provides about 0.005--0.5 gram atom of aluminum per mole aromatic diamine to be alkylated. A more preferred range is about 0.1-0.25 gram atom aluminum per mole diamine.
The alkylation is carried out by adding the catalyst precursor to the diamine or mixture of diamines, optionally with aniline. This is heated under nitrogen in a sealed autoclave to form the catalyst. After the catalyst forms the autoclave is cooled and vented although venting is not required. The autoclave is then sealed and heated to an elevated reaction temperature. A useful range for carrying out the alkylation is about 200°-500° C. A preferred temperature is about 300°-400° C.
It is therefore an object of the present invention to provide a straightforward, relatively inexpensive process for the production of dialkyl-diaminobenzenes.
It is also an object of the present invention to provide the novel and useful compound 1-methyl-2,4-diamino-5-isopropylbenzene.
It is another object of this invention to provide an efficient alkylation process which doesn't require expensive catalysts such as platinum or silver.
It is still another object of this invention to provide monoalkylation of 1-alkyl-2,4-diaminobenzene and/or 1-alkyl-2,6-diaminobenzene in preference over dialkylation or trialkylation.
These and other objects of the present invention will be better understood by a reading of the following description of the best mode of the invention now known to me.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The following non-limiting examples serve to illustrate the invention.
Example 1
Liquified propylene was drawn into a pressure burrette with a piston device. The filled pressure burrette was used to provide a measured amount of propylene at constant pressure to a one-liter autoclave fitted with a dropping funnel and adapter. The autoclave was charged with:
(a) 219.6 grams (1.8 moles) 2,4-diaminotoluene obtained from Aldrich Chemical Company and distilled;
(b) 41 grams (0.36 mole) triethylaluminum of Ethyl Corporation (added dropwise over 15 minutes); and
(c) 33.5 grams (0.36 mole) aniline.
The dropping funnel and adapter were removed, the autoclave was sealed and heated to 150° C. for catalyst formation. The autoclave was allowed to cool and vented.
The autoclave was again sealed and heated to 300° C. as propylene was fed from the burrette at 1,000 psig. The propylene has a specific gravity of 0.5146 at 68° F. Samples of about 15 grams each were taken after one, three, and six hours. Analysis of the three samples is shown in Table 1.
TABLE 1______________________________________Propylation Of 2,4-Diaminotoluene % 2,4-Sample % Diamino- % Mono-No. Aniline toluene propyl % Dipropyl______________________________________1 7 34 42 --2 7 18 50 53 6 9 53 7______________________________________
The reaction mass of 203 grams was discharged from the autoclave and hydrolyzed with 25% NaOH to convert the aluminum to a water soluble form. The organics were filtered hot to provide 187 grams product. The product was purified by distillation in a one-inch by 13-inch column packed with protruded stainless steel. Analysis by gas chromatography, NMR, and infrared spectroscopy confirmed that the principal product was 1-methyl-2,4-diamino-5-isopropylbenzene.
Example 2
The same procedure and stoichiometry was followed as in Example 1, but using 2,6-diaminotoluene. Samples were taken after one, two, four, and six and one-half hours. The analysis of these samples is presented in Table 2. The results demonstrate that the reaction must be controlled terminated early to preserve the monopropylated product as the principal product.
TABLE 2______________________________________Propylation Of 2,6-Diaminotoluene % 2,6-Sample % Diamino- % Mono-No. Aniline toluene propyl % Dipropyl______________________________________1 8 20 45 212 8 8 37 413 7 5 18 634 7 6 11 69______________________________________
The reaction mass of 264 grams was discharged from the autoclave and recovered as in Example 1 to provide 247 grams product which was purified by distillation.
Example 2A
Following the same procedure and proportions of materials as in Examples 1 and 2 (5:1:1) the process of the invention was carried out using a toluenediamine (TDA) stream having 80% 2,4-TDA and about 20% 2,6-TDA. The crude product was 10% aniline, 15% unreacted TDA, 53% mono-propyl TDA's and 12% dipropyl TDA's. The reaction mixture was hydrolyzed, flash distilled and then fractionated to remove unreacted TDA. The product was then flash distilled to provide 185 grams of the composition given in Table 3.
TABLE 3______________________________________Propylation of Mixed TDA's______________________________________1-methyl-2,6-diamino-3-isopropylbenzene 18%1-methyl-2,4-diamino-5-isopropylbenzene 54%1-methyl-2,4-diamino-3,5-diisopropylbenzene 8%1-methyl-2,6-diamino-3,5-diisopropylbenzene 16.8%1-methyl-diamino-isopropyl-n-propylbenzene 1.7%______________________________________
The first listed compound was confirmed to have the structure: ##STR4## by gas chromatography, NMR, and infrared spectroscopy analyses.
Example 3
A small sample of the 1-methyl-2,4-diamino-5-isopropylbenzene component of the yield from Example 1 was tested as a polyurethane chain extender.
The following ingredients were used:
12.5 grams Jefferson 6503 polyol;
5.3 grams Upjohn Isonate 1431 MDI (polyisocyanate);
2.61 grams 1-methyl-2,4-diamino-5-isopropylbenzene;
1 drop of dibutyl tin dilaurate (catalyst).
The novel 1-methyl-2,4-diamino-5-isopropylbenzene and polyol were mixed, placed in an air circulated oven at 150° C. until homogeneous, and cooled to room temperature in a nitrogen bag. The one drop of catalyst was added and mixed. Finally, the MDI was quickly added and the mixture stirred by hand to form a hard polymer. The following times, indicating polyurethane formation, were noted:
Gelation Time--a thickening of the reaction mixture is noticeable: 4 seconds;
Tack-Free Time--the surface of the mixture will not stick to an object: 5 seconds;
Firm Time--the reaction mass will not yield under manual pressure: 6 seconds.
The above data indicate the usefulness of the novel compound as a chain extender especially for reaction injection molding.
The above description and non-limiting examples serve to illustrate the invention but various aspects of the invention may be varied without departing from the scope or spirit thereof as defined by the appended claims.
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A process for monoalkylating 1-alkyl-2,4-diaminobenzene or 1-alkyl-2,6-diaminobenzene. Propylene is reacted with 2,4-diaminotoluene in the presence of aluminum anilide catalyst. Aniline is an optional ingredient. 1-Methyl-2,6-diamino-3-isopropylbenzene is a new compound: ##STR1##
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Application No. 61/110,175, filed Oct. 31, 2008, which is hereby incorporated by reference in its entirety for all purposes.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not applicable.
BACKGROUND
[0003] 1. Field of the Invention
[0004] This invention relates generally to the field of drilling. More specifically, the invention relates to compositions and methods for annular pressure buildup mitigation.
[0005] 2. Background of the Invention
[0006] Natural resources such as oil or gas residing in a subterranean formation are recovered by drilling a well into the formation. The subterranean formation is usually isolated from other formations using a technique known as well cementing. In particular, a wellbore is typically drilled down to the subterranean formation while circulating a drilling fluid through the wellbore. After the drilling is terminated, a string of pipe (e.g. drill string, casing) is run in the wellbore. Primary cementing is then usually performed where cement slurry is pumped down through the string of pipe and into the annulus between the string of pipe and the walls of the wellbore to allow the cement slurry to set into an impermeable cement column and thereby seal the annulus. Secondary cementing operations may also be performed after the primary cementing operation.
[0007] After completion of the cementing operations, production of the oil or gas may commence. The oil and gas are produced at the surface after flowing through the wellbore. As the oil and gas pass through the wellbore, heat may be passed from such fluids through the casing and into the annular space, which typically results in expansion of any fluids in the annular space.
[0008] Annular pressure build-up (APB) is a potentially dangerous condition in wells caused by a temperature driven increase in pressure within the annuli formed by downhole strings. APB situations commonly occur in subsea wells, where annuli between adjacent casing strings are sealed from above by wellhead equipment at the mudline and from below by cement tops or barite plugs. Pressure within the annuli is built up as the temperature within the annuli is increased due to the expansion of drilling fluids within the annuli. A significant increase in pressure within the annuli may have adverse consequences such as rupture of the casing wall or catastrophic collapse of the drilling string itself or of the production tubing through which wellbore fluids are brought to surface.
[0009] Several techniques for mitigating APB have already been developed and employed with some regularity in the industry. One mitigator, for example, is syntactic foam composed of hollow glass elastic hollow particles with prescribed dimensions. The foam is attached to the outside surface of the inner string of the annulus. Onset of APB above a particular pressure level causes the elastic hollow particles to collapse and break, increasing the available volume of the annulus. These and other commonly used techniques, however, are limited in utility in that they provide only a one-time relief of APB; once activated, the mitigator cannot relieve future instances of pressure buildup.
[0010] Consequently, there is a need for more effective compositions and methods for mitigating annular pressure buildup.
BRIEF SUMMARY
[0011] The concept involves placing within the annulus, hollow particles that possess material and geometric properties such that the hollow particles buckle at or near a defined pressure. Buckling of the particles increases the available volume within the annulus, thereby decreasing the annular pressure. The elastic hollow particles are designed such that they buckle in a sufficiently elastic manner to allow them to rebound towards their original shape as the pressure decreases. The rebounded particles then remain available to mitigate subsequent instances of APB.
[0012] In an embodiment, a method of mitigating annular pressure buildup comprises providing a wellbore composition comprising a plurality of elastic hollow particles. The method further comprises introducing the wellbore composition to an annulus of a wellbore. In addition, the method comprises using the plurality of elastic hollow particles to mitigate annular pressure buildup. The elastic hollow particles buckle above an annular pressure threshold and rebound below the annular pressure threshold.
[0013] In another embodiment, a method of mitigating annular pressure buildup comprises providing a wellbore composition comprising a plurality of elliptical hollow particle. The elliptical hollow particles are elastic. The method additionally comprises introducing the wellbore composition to an annulus of a wellbore. Moreover, the method comprises using the plurality of elliptical hollow particles to mitigate annular pressure buildup. The elliptical hollow particles buckle above an annular pressure threshold and rebound below the annular pressure threshold.
[0014] In yet another embodiment, a method of mitigating annular pressure buildup comprises providing a wellbore composition comprising a plurality of elastic hollow particles having at least two segments. The method also comprises introducing the wellbore composition to an annulus of a wellbore. In addition, the method comprises using the plurality of elastic hollow particles to mitigate annular pressure buildup. The elastic hollow particles buckle above an annular pressure threshold and rebound below the annular pressure threshold.
[0015] The foregoing has outlined rather broadly the features and technical advantages of the invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter that form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and the specific embodiments disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] For a detailed description of the preferred embodiments of the invention, reference will now be made to the accompanying drawings in which:
[0017] FIG. 1 illustrates an embodiment of an elastic hollow particle which may be used with the disclosed methods;
[0018] FIG. 2 illustrates an elliptical embodiment of an elastic hollow particle which may be used with the disclosed methods;
[0019] FIG. 3 illustrates a pressure-volume curve for the compression of water and a sample of polypropylene elastic hollow particles;
[0020] FIG. 4 illustrates a pressure-volume curve for the compression of water and another sample of polypropylene elastic hollow particles;
[0021] FIG. 5 illustrates a pressure-volume curve for the compression of water and another sample of polypropylene elastic hollow particles;
[0022] FIG. 6 illustrates a pressure-volume curve for the compression of water and a sample of high-density polyethylene elastic hollow particles; and
[0023] FIG. 7 illustrates a pressure-volume curve for the compression of water and another sample of high-density polyethylene elastic hollow particles.
NOTATION AND NOMENCLATURE
[0024] Certain terms are used throughout the following description and claims to refer to particular system components. This document does not intend to distinguish between components that differ in name but not function.
[0025] In the following discussion and in the claims, the terms “including” and “comprising” are used in an open-ended fashion, and thus should be interpreted to mean “including, but not limited to . . . ”. Also, the term “couple” or “couples” is intended to mean either an indirect or direct connection. Thus, if a first device couples to a second device, that connection may be through a direct connection, or through an indirect connection via other devices and connections.
[0026] As used herein, the term “elastic” may refer to the ability of a material or particle to resume or return toward its original shape after compression or deformation.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0027] In general, embodiments of the disclosed methods for mitigating annular pressure buildup utilize a wellbore composition comprising a plurality of elastic hollow particles. FIG. 1 illustrates an embodiment of an elastic hollow particle 100 which may be used in the wellbore composition. In an embodiment, the elastic hollow particle 100 comprises a shell 103 of elastic polymeric material and an inner hollow cavity 105 . The plurality of elastic hollow particles 100 may be mixed with an existing wellbore fluid and injected into the annulus of a wellbore. In instances of annular pressure buildup, the elastic hollow particles 100 may buckle to alleviate the pressure within the annulus and effectively provide more volume within the annulus. Once the temperature within the annulus has been decreased and the APB as been reduced, elastic hollow particles 100 are capable of rebounding to their original shape and are, thus, re-usable for subsequent instances of APB. By comparison, existing particles and APB mitigators only provide for one time mitigation of APB.
[0028] Elastic hollow particle 100 may be any suitable shape. In an embodiment, elastic hollow particle 100 may have a spherical shape. FIG. 1 shows an example of such an embodiment of elastic hollow particle with an outer spherical shape. In other embodiments, elastic hollow particle 100 may comprise variations of a sphere such as without limitation, prolate spheroid, oblate spheroid, spheres, ovoids (i.e. egg shaped), etc, such as depicted in FIG. 2 . In other words, elastic hollow particle 100 may comprise an elliptical hollow particle 100 a. Referring to FIG. 2D , elliptical hollow particle 100 a may have a semi-major axis, a, and a semi-minor axis, b. Axes a and b may be of any suitable length. More particularly, axis a may have a length ranging from about 50 mm to about 0.1 mm, alternatively from about 25 mm to about 2 mm, alternatively from about 5 mm to about 1 mm. Axis b may have a length ranging from about 50 mm to about 0.1 mm, alternatively from about 25 mm to about 2 mm, alternatively from about 5 mm to about 1 mm. In addition, axes a and b may be of any suitable ratio to each other. Referring to FIG. 2A , in an embodiment, elliptical hollow particle 100 a may have a circular cross-section (i.e. prolate spheroid). However, it is contemplated that elliptical hollow particle 100 a may also have an elliptical cross-section (i.e. oblate spheroid). As such, axes b and c in FIG. 2A may be different from one another and may be of any suitable ratio to one another. Axis c may be of any length. More particularly, axis c may have a length ranging from about 50 mm to about 0.1 mm, alternatively from about 25 mm to about 2 mm, alternatively from about 5 mm to about 1 mm.
[0029] Inner cavity 105 if elastic hollow particle 100 may be filled with any suitable fluid or material (e.g. gas, liquid, foam) at a range of pressures (atmospheric or higher). Examples of suitable fluids include without limitation, air, inert gas, or combinations thereof. Inner cavity 105 of elastic hollow particle 100 may have the same geometry or a different geometry than that of the shell 103 . For example, shell 103 may comprise a spherical geometry while inner cavity may have a prolate spheriodal geometry.
[0030] Furthermore, in some embodiments, elastic hollow particles 100 may comprise at least two segments 106 . That is, the elastic hollow particles 100 are segmented hollow particles. The elastic hollow particles 100 may be fabricated from any number of segments 106 . In one embodiment, elastic hollow particles have two segments 106 . The segments 106 may fit together via a snap-fit connection 109 or other suitable connection, such as for example, welding. Inner cavity 103 may be filled with any suitable fluid or material (e.g. gas, liquid, foam) at a range of pressures (atmospheric or higher). Examples of suitable fluids include without limitation, air, inert gas, or combinations thereof. Inner cavity 105 of elastic hollow particle 100 may have the same geometry or a different geometry than that of the shell 103 . For example, shell 103 may comprise a spherical geometry while inner cavity may have a prolate spheroidal geometry.
[0031] Elastic hollow particles 100 may be manufactured by any methods known to those of skill in the art. In one embodiment, elastic hollow particles 100 may be made by injection molding.
[0032] As mentioned above, shell 103 of elastic hollow particle 100 preferably comprises an elastic polymeric material. However, shell 103 may comprise any suitable material which exhibits the requisite elastic properties for mitigating annular pressure buildup. Examples of suitable polymeric materials include without limitation, polybutadiene, ethylene propylene diene (EPDM) rubber, silicone, polyurethane, polyamide, acetal, thermoplastic elastomers, polypropylene, polyethylene, polytetrafluoroethylene (PTFE), polyvinylidenefluoride (PVDF), or combinations thereof. The elastic polymeric material may be a copolymer, a random copolymer, a block copolymer, a multiblock copolymer, a polymer blend, or combinations thereof.
[0033] The elastic hollow particles 100 may have any suitable diameter. More specifically, embodiments of the elastic hollow particles 100 may have an average outer diameter ranging from about 50 mm to about 0.1 mm, alternatively from about 25 mm to about 2 mm, alternatively from about 5 mm to about 1 mm. Additionally, elastic hollow particles 100 may have any suitable shell thicknesses. In particular, embodiments of the elastic hollow particles may have an average shell thickness ranging from about 10 mm to about 5 mm, alternatively from about 5mm to about 1 mm, alternatively from about 1 mm to about 0.1 mm. Inner cavity 105 of elastic hollow particle 100 may have any suitable diameter. For example, inner cavity 105 may have an average diameter ranging from about 50 mm to about 25 mm, alternatively from about 25 mm to about 5 mm, alternatively from about 5 mm to about 0.1 mm.
[0034] In embodiments, the elastic hollow particles 100 have very specific mechanical properties in order to properly mitigate annular pressure buildup. In particular, elastic hollow particles 100 may have an elastic modulus at 25° C. ranging from about 100 GPa to about 10 MPa, alternatively from about 1 GPa to about 100 MPa, alternatively from about 100 MPa to about 10 MPa. Furthermore, elastic hollow particles 100 may have a yield strain at about 25° C. ranging from about 100% to about 50%, alternatively from about 50% to about 10%, alternatively from about 10% to about 1%. In other words, the elastic hollow particles 100 may be designed to buckle at a specific annular pressure and/or temperature. As used herein, “annular pressure threshold” is the pressure within the annulus for which the elastic hollow particles 100 may be designed to compress or buckle at a given temperature. Accordingly, the elastic hollow particles 100 may buckle or compress at an annular pressure threshold ranging from about 15,000 psi to about 10,000 psi, alternatively from about 10,000 psi to about 5,000 psi, alternatively from about 5,000 psi to about 500 psi.
[0035] In addition, elastic hollow particles 100 provide greater volume compression than solid particles. Accordingly, each elastic hollow particle 100 may compress to an average volume ranging from about 99% to about 50% of its original volume, alternatively from about 50% to about 10% of its original volume, alternatively from about 10% to about 1% of its original volume. With respect to elasticity, the elastic hollow particles 100 preferably rebound or return to at least about 99% of their original volume, alternatively at least about 50% of their original volume, alternatively at least about 10% of their original volume.
[0036] The elastic hollow particles 100 may be used in conjunction with any wellbore composition and/or fluids known to those of skill in the art. Examples of known wellbore fluids include without limitation, production fluids, drilling muds, spacer fluids, chemical pills, completion fluids, or combinations thereof. As such, the elastic hollow particles 100 may be present in a fluid composition at a concentration ranging from about 70 vol % to about 25 vol %, alternatively from about 25 vol % to about 1 vol %.
[0037] The wellbore composition may include additional fluids and additives commonly used in existing wellbore treatment fluids. In particular, the wellbore composition may comprise an aqueous-based fluid or a nonaqueous-based fluid. Without limitation, examples of suitable aqueous-based fluids include fresh water, salt water (e.g., water containing one or more salts dissolved therein), brine (e.g., saturated salt water), seawater, water-based drilling fluids (e.g., water-based drilling fluid comprising additives such as clay additives), and combinations thereof. Examples of suitable nonaqueous-based fluids include without limitation, diesel, crude oil, kerosene, aromatic mineral oils, non-aromatic mineral oils, linear alpha olefins, poly alpha olefins, internal or isomerized olefins, linear alpha benzene, esters, ethers, linear paraffins, or combinations thereof. For instance, the non-aqueous-based fluids may be blends such as internal olefin and ester blends. In some embodiments, the additional fluids and/or additives may be present in the wellbore composition in an amount sufficient to form a pumpable wellbore fluid.
[0038] The elastic hollow particles 100 may be placed in a subterranean annulus in any suitable fashion. For example, the elastic hollow particles 100 may be placed into the annulus directly from the surface. Alternatively, the elastic hollow particles 100 may be flowed into a wellbore as part of a wellbore composition via the casing and permitted to circulate into place in the annulus between the casing and the subterranean formation. Generally, an operator will circulate one or more additional fluids (e.g., a cement composition) into place within the subterranean annulus behind the well fluids of the present invention therein; in certain exemplary embodiments, the additional fluids do not mix with the well fluids of the present invention. At least a portion of the well fluids of the present invention then may become trapped within the subterranean annulus; in certain exemplary embodiments of the present invention, the well fluids of the present invention may become trapped at a point in time after a cement composition has been circulated into a desired position within the annulus to the operator's satisfaction. At least a portion of the elastic hollow particles 100 may collapse or reduce in volume so as to affect the pressure in the annulus. For example, if the temperature in the annulus should increase after the onset of hydrocarbon production from the subterranean formation, at least a portion of the hollow particles 100 may collapse or reduce in volume so as to desirably mitigate, or prevent, an undesirable buildup of pressure within the annulus.
[0039] To further illustrate various illustrative embodiments of the present invention, the following examples are provided.
EXAMPLE 1
[0040] A variety of industries and materials suppliers were surveyed to locate readily available, off-the-shelf hollow polymer particles. The search criteria were limited to the following: the particles had to be hollow and made of plastic or rubber, with an outside diameter of no more than 10 mm. While the downhole operating requirements are much more stringent, these relatively simple criteria allowed acquisition of particles that could serve as potential concept demonstrators.
[0041] After considering a variety of experimental techniques for applying elevated pressures on the order of 15,000 psi and measuring changes in volume demonstrated by the elastic hollow particles, a High Pressure Pump Model 68-5.75-15 from High Pressure Equipment (HiP) was acquired. This device is a manual screw-driven pressure generator that is capable of applying pressures up to 15,000 psi in a small cylindrical chamber approximately 16 inches long and 11/16 inch in diameter. For each experiment, the test chamber was filled with a mixture of water and elastic hollow particles and care was taken to minimize the amount of air remaining in the chamber. A digital pressure gauge measured the pressure applied to the test samples, while a linear voltage displacement transducer (LVDT) on the drive screw measured the applied volume change.
EXAMPLE 2
[0042] This experiment involved two pressure cycles up to 10,000 psi of an 11.6% mixture in volume of a sample of polypropylene hollow particles (Sample 1) and water. The elastic hollow particles used for this experiment had an outside diameter of 2.5 mm and a variable size cavity. Microscopic exploration revealed that the size of the cavity was minimal. As a result, the pressure-volume curve (as shown in FIG. 3 ) was very similar to that obtained in an experiment involving only the compression of water and residual air.
EXAMPLE 3
[0043] This experiment involved two pressure cycles of a 5.6% mixture in volume of another sample of polypropylene elastic hollow particles (Sample 2) and water. Results are shown in FIG. 4 . The polypropylene elastic hollow particles had a 10 mm diameter and a 1 mm wall thickness. The sound of the elastic hollow particles collapsing could be heard under the increasing pressure. As seen in the pressure-volume response, every collapsed particle provided additional volume and relieved the pressure in the chamber. Most of the elastic hollow particles, with the exception of two, failed close to 2,000 psi. The failure mode representative of all ten elastic hollow particles is shown in FIG. 3 .
[0044] The maximum pressure did not significantly exceed 2,000 psi until collapse of the final particle, which occurred at about 6.5% change in volume. This location on the plot is about 5% change in volume above the point at which the pressure first began to depart from 0 psi (1.5%). This value of 5% change in volume can be compared to the results of the experiment involving only water and residual air. In that experiment, the pressure exceeded 2,000 psi at about 4.5% change in volume, which is about 1.5% change in volume above the point at which the pressure first began to depart from 0 psi. These results show that collapse of the elastic hollow particles provided additional volume and prevented the pressure from increasing. Only when all elastic hollow particles were collapsed did the pressure increase dramatically. Selection of appropriate material and geometry for the elastic hollow particles could make this pressure relief available on a repeatable basis.
EXAMPLE 4
[0045] The fourth experiment involved a single pressure cycle of a 3.4% volume fraction mixture of another sample of polypropylene elastic hollow particles (Sample 4) and water. The elastic hollow particles in this sample had a diameter of 10 mm and a wall thickness of 3 mm. The results are shown in FIG. 5 . As shown, the elastic hollow particles exhibited pressure relief at approximately 10,000 psi. The slope of the pressure-volume curve decreased in a gradual fashion as the elastic hollow particles collapsed. At the conclusion of the experiment, the chamber was opened and the elastic hollow particles were observed to be undeformed, indicating that the elastic hollow particles had collapsed elastically.
[0046] Hysteresis in the first cycle indicated viscoelastic material behavior of the elastic hollow particles; deformation during the first cycle likely changed the material stiffness. In this respect, the first cycle likely “pre-conditioned” the hollow particles. It is expected that collapse during the second cycle would demonstrate behavior differing from that shown in the first cycle, yet would be repeatable in cycles beyond the second cycle. An issue with instrumentation caused this particular experiment to be terminated before the second cycle could be completed. Further experimentation with these hollow particles, particularly involving multiple pressure cycles, is necessary to confirm the above observations and to further understand the potential for pressure relief provided by these elastic particles.
EXAMPLE 5
[0047] FIGS. 6 and 7 show the results of pressure-volume experiments performed with samples of elastic hollow particles fabricated with high-density polyethylene (HDPE). FIG. 6 shows results using HDPE elastic hollow particles with outer diameter of 0.25 inches and a shell thickness of 1.3 mm. FIG. 7 shows the results using HDPE elastic hollow particles with outer diameter of 10 mm and a shell thickness of 1 mm. These results provide further proof of concept that elastic hollow particles with different types of polymers may be applied to APB mitigation.
[0048] While the embodiments of the invention have been shown and described, modifications thereof can be made by one skilled in the art without departing from the spirit and teachings of the invention. The embodiments described and the examples provided herein are exemplary only, and are not intended to be limiting. Many variations and modifications of the invention disclosed herein are possible and are within the scope of the invention. Accordingly, the scope of protection is not limited by the description set out above, but is only limited by the claims which follow, that scope including all equivalents of the subject matter of the claims.
[0049] The discussion of a reference is not an admission that it is prior art to the present invention, especially any reference that may have a publication date after the priority date of this application. The disclosures of all patents, patent applications, and publications cited herein are hereby incorporated herein by reference in their entirety, to the extent that they provide exemplary, procedural, or other details supplementary to those set forth herein.
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The concept involves placing within the annulus, hollow particles that possess material and geometric properties such that the hollow particles buckle at or near a defined pressure. Buckling of the particles increases the available volume within the annulus, thereby decreasing the annular pressure. The elastic hollow particles are designed such that they buckle in a sufficiently elastic manner to allow them to rebound towards their original shape as the pressure decreases. The rebounded particles then remain available to mitigate subsequent instances of APB.
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FIELD OF THE INVENTION
[0001] The present invention relates to the field of packaging preassembled (prehung) door and frame assemblies for shipping and handling.
BACKGROUND OF THE INFORMATION
[0002] It is common practice in the building industry to preassemble doors and frames into a unit (called a prehung door and frame assembly) at a factory and ship the same for eventual use in constructing buildings. These prehung doors are packaged with bands and corner boots to secure their shipment to stores and construction sites.
SUMMARY OF THE INVENTION
[0003] The present invention comprises a container for shipping hardware such as door knobs, hinges, framing wedges and the like with prehung door and frame assemblies. The container comprises a substantially rectangular configuration having a container portion and a jamb panel extending therefrom that wraps around the outside one of the jambs of the frame to secure the container to the prehung door and frame assembly and to protect the jamb during shipment. The depth of the container is the same or less than the depth of the cavity side of the prehung door and frame assembly and the front wall of the container fits beneath or flush with the edge of the jamb on the cavity side of the frame. The combined container and jamb protector may be formed by a single blank of foldable protective sheet material folded to define said container and said jamb panel.
[0004] These and other features, objects and advantages of the corner protector container will be more fully understood and appreciated by reference to the description of the preferred embodiments, and the appended drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] Further objects and advantages of the container will become apparent from the following description and claims, and from the accompanying drawings, wherein:
[0006] FIGS. 1 and 1 a show isometric images of cavity side and flush door side of a prehung door and frame assembly with two corner protector containers 10 embodiments positioned in place on upper left and right coolers and one container embodiment 100 positioned in place along the lower right side.
[0007] FIG. 2 is a top plane view of a blank used to form the corner protector container 10 .
[0008] FIG. 3 is a front view of the folded corner protector container 10 .
[0009] FIG. 4 is an end view of the folded corner protector container 10 .
[0010] FIG. 5 is a view of the corner protector container 10 mounted in the upper right hand corner of a prehung door assembly.
[0011] FIG. 6 is door side view of the tipper right hand corner mounted corner protector container 10 as shown in FIG. 5 .
[0012] FIG. 7 is a perspective view illustrating an intermediate folding of the blank of FIG. 2 to form the corner protector container 10 of the present invention.
[0013] FIG. 8 is a top plane view of a blank that may be used to prepare the container embodiment 100 .
[0014] FIG. 9 is a perspective vie w illustrating inter mediate folding of the blank used to prepare the container embodiment 100 .
[0015] FIG. 10 is a perspective view showing the complete folding of the container 121 of container embodiment 100 except for closing of the container first side wall.
[0016] FIG. 11 illustrates container embodiment 100 with container 121 abutting the inside of a jamb in combination with a standard corner protector 122 .
[0017] FIG. 12 illustrates a door side view of container embodiment showing jamb panel 117 and door side panel 118 wrapped around the outside face and door side edge of a hinge jamb.
[0018] FIG. 13 is a top plane view of another embodiment of a blank that can be used to prepare the combined container and jamb protector.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0019] In the following description of the preferred embodiments, the numbered parts in the Figures have the following meanings:
10 —corner protector container 11 —blank 12 —container first side wall 12 a —fold line 13 —container back wall 13 a —locking key 13 b —fold line 14 —container second side wall 14 a —fold line 15 —container front wall 15 a —tie 15 b —fold line 15 c —fold line 15 d —cut line 16 —container bottom 16 a —key slot
[0036] 16 b —fold line
16 c —fold line 17 —jamb panel 17 a —key slot 17 b —fold slot 17 c —fold line 18 —second jamb panel 18 a —fold line 19 —fold under flap 19 a —key 19 b —fold line 20 —door side panel 20 a —door side tie 20 b —fold line 20 c —fold line 20 d —cut line 21 —bottom flap 22 —container 23 —jamb channel 24 —second jamb channel 25 —envelope 30 —prehung door and frame assembly 31 —head jamb 32 —hinge jamb 33 —striker jamb 34 —door 35 —predrilled holes for lock and handles 36 —hinges 37 —stop 38 —shipping band 39 —deep side cavity of door and frame 100 —container embodiment 110 —blank for container embodiment 111 —container first side wall 111 a —fold line 112 —container back wall 112 a —first locking key 112 —second locking key 112 c —fold line 112 d —fold line 113 —container second side wall 114 —container front wall 114 a —fold line 114 b —fold line 114 c —fold line 115 —container bottom 115 a —key slot 115 b —fold line 116 —container top 116 a —key slot 116 b —fold line 117 —jamb panel 117 a —fold line 117 b —fold line 118 —door side panel 119 —bottom flap 120 —top flap 121 —container 122 —standard jamb corner protector 123 —jamb channel 210 —second embodiment of blank for container embodiment 211 —container first side wall 211 a —fold line 211 b —locking key 211 c —fold line 211 d —fold tine 212 —container back wall 213 —container second side wall 213 a —fold line 213 b —locking key 213 c —fold line 213 d —fold line 214 —container front wall 214 a —fold line 215 —container bottom 215 a —key slot 215 b —fold Sine 216 —container top 216 a —key slot 216 b —fold line 217 —jamb panel 217 a —fold line 217 b —fold line 218 —door side panel 219 —bottom flap 220 —top flap
[0122] It is not intended the invention be limited to the specific embodiments shown and described.
[0123] FIGS. 1 and 1 a illustrate a prehung door and frame assembly 30 with two corner protector containers 10 positioned in the tipper right and left corners of the prehung door assembly 30 and container embodiment 100 positioned on the lower right ( FIG. 1 ) side i.e. the hinge jamb 32 . FIG. 1 shows the cavity side 39 and FIG. 1 a the door side of the prehung door and frame assembly 30 . In a prehung door assembly the door 34 is usually hung from the hinge jamb 32 with hinges 36 so the door 34 is flush to the edges of head jamb 31 , hinge jamb 32 and striker jamb 33 on one side of the assembly ( FIG. 1 a ). Because of the width of the jambs a cavity 39 is formed on the other side of the assembly. The door 34 usually has predrilled holes 35 for mounting lock and handle. The three jambs have a stop 37 running parallel to their edges on the cavity side 39 to prevent the door from moving through the frame formed by the jambs when closed. Two of the corner protector containers 10 are shown mounted in the cavity 39 , one in the right upper corner and one in the left upper corner. Container embodiment 100 is shown mounted in the cavity 39 on the hinge jamb 32 . The corner protector container 10 is held in place when the corner protector container 10 is assembled over the jambs. It can be further secured with a shipping band 38 . In this embodiment the corner protector container 10 is rectangular, it could also be square. The length and width of the corner proctor container can range from about a few inches to about ninety percent of the length and width of the cavity 39 , The width of side walls 12 and 14 (W 1 and W 3 ) i.e. depth, is preferably no greater than the depth of the cavity 39 or the stops 37 whichever is less so the container front wall 15 is flush with the top edges of the jambs or the front wall is below the level of the edges of the jambs. The corner protector container 10 slips over the head jamb by inserting it into the jamb channel 23 and either the hinge jamb 32 or the striker jamb 33 by inserting it into the second jamb channel 24 and the container 22 sits inside the cavity 39 and the container front wall 15 is shown flush with the edges of the jambs. The open end formed by the top edges of 12 , 13 and 14 end of the container portion 22 abuts against inside of the jamb to hold articles put into the container 22 for shipment with the prehung door and frame assembly 30 . The jamb panel 17 of the corner protector container 10 fits over either the head jamb 31 or the hinge jamb 32 and the second jamb panel 18 fits over the other jamb. The door side panel 20 folds down over and fits flash with the door 34 and ties into the jamb panel 17 and locks the corner protector 10 onto the prehung door and frame assembly (see FIG. 1 a ).
[0124] Referring to FIGS. 2, 8 and 13 , the corner protector container 10 can be formed from a unitary, planar, generally rectangular paperboard blank 11 and the container embodiment 100 from, blank 110 or 210 . in the FIGS. a dashed—line indicates fold lines and an x-x-x line represents a cut line (i.e. the paper board is cut along this line to permit folding of that portion of the blank 11 ). Fold lines are preferably scored such as by press scoring to reduce the paper stiffness along the fold line enabling an accurate fold of the paper board alone the designated fold lines.
[0125] Referring to FIG. 2 , blank 11 includes a container first side wall 12 connected by a fold line 12 a to container back wall 13 which will face toward the door 34 when folded and placed. The container back wall 13 has locking key 13 a extending from near the center of its lower edge along fold line 13 b. The container back wall 13 is connected by a fold line 14 a to container second side wall 14 . The container second side wall 14 is connected by a fold line 15 b to a container front wall 15 which faces toward the outside of the cavity. Extending from the top of the container front wall 15 and connected by a fold line 15 c is a tie 15 a which has a cut line 15 d running from, the top to the fold line 15 c. The tie 15 a preferably has a tapering or rounded top edge to facilitate ease in folding the blank into the corner protector container 10 . In the embodiment in FIG. 2 extending from the bottom edge of the container front wall 15 and connected thereto by fold line 16 b is a container bottom 16 which functions to close the bottom of the container 22 . Extending from the bottom edge of the container bottom 16 through fold line 16 c is a bottom flap 21 . A key slot 16 a is centrally formed along the fold line 16 c for receiving the locking key 13 a when forming the corner protector container 10 . The container bottom 16 has a width W 4 starting at fold line 15 b no greater than the width W 2 of the container back wall 13 and less than the width W 5 of the container front wall 15 . The difference between W 2 and W 5 forms a jamb channel 23 when the corner protector container 50 is folded into shape. The container bottom 16 can be less than the width of the back wall 16 but should be wide enough to retain the articles placed in the container for shipment. The container bottom 16 has a length L 3 equal to the width W 1 of the container first side wall 12 which preferably has the same width or can. be less than W 3 as the container second side wall 14 . The bottom flap 21 has the same width W 4 as the container bottom 16 and a length no longer than the length of the container bottom 16 . Alternatively the container bottom 16 can be formed by extending the container bottom 16 from the first side 12 wall as shown in FIG. 13 with the locking key being formed at the bottom of the second side wall. The reverse can also be employed i.e. extending the bottom 16 from the bottom of the second side wall 14 with the locking key being formed at the bottom of the first side wall 12 . Connected to container front wall 15 by fold line 17 b is a jamb panel 17 . Defining the top edge of jamb panel 17 is fold line 17 c. Formed along the lower edge of the fold line 17 c is a centrally located key slot 17 a for receiving key 19 a. Connected to the upper part of jamb panel 17 through fold line 17 c is a second jamb panel 18 . The width W 6 of the jamb panels 17 and 18 is about the same as width of the jambs making up the frame of the prehung door and frame assembly 30 to which the corner protector container 10 is attached. The fold lines 15 c, 17 c and 20 c lie in a straight line. The length L 2 of the jamb panel 17 and door side panel 20 and the fold line 17 b is the same as the longest length of the container front wall 15 . The length L 2 is longer than the length L 1 by an amount at least as great as the thickness of the jambs of the frame of the prehung door and frame assembly 30 . When folded the additional length L 2 forms a second jamb channel 24 in the corner protector container 10 between the top of the first side wall 12 , back wall 13 and second side wall 14 when the container is folded into shape. In FIG. 2 the bottom edges of 12 , 13 , 14 , fold line 16 b, 17 , and 20 are aligned in a straight line, however the bottom edges of 17 and 20 can be above or below the bottom edges of edges of 12 , 13 , 14 and fold line 16 b, Connected to the top edge of the second jamb panel 18 is fold under flap 19 that has a width W 8 slightly narrower than the width W 6 of the second jamb panel 18 . The fold under flap 19 is connected to the second jamb panel 18 through two parallel fold lines 18 a and 19 b. Defined in the top edge of the fold under flap 19 is key 19 a that mates with key slot 17 a when the corner protector container 10 is folded into shape. The length L 4 of the jamb panel 18 can vary. The length L 5 of the fold under flap 19 is about the same as the length L 4 of the jamb panel 18 . In this embodiment the width W 8 of the fold down under flap 19 is slightly less than the width of the jamb panel 18 . This facilitates the insertion of the tie 15 a and door side tie 20 a into the envelope 25 formed when the fold under flap is folded into place under the jamb panel 18 . Connected to jamb panel 17 through fold line 20 b is door side panel 20 . The width W 7 of the door side panel 20 can vary. Along the top edge of the door side pane 120 is fold line 20 c that has connected to it door side tie 20 a. Door side tie 20 a has cut line 20 d that permits the tie 20 a to be folded down away from the door side panel 20 so that when folded perpendicular to jamb panel 17 the door side tie 20 a, as is tie 15 a, can be inserted into an envelope 25 formed when fold under flap 19 is folded under onto second jamb panel 18 and key 19 a is inserted-into key slot 17 a. This locks the door side panel into second jamb panel 18 . Friction between the parts secures the corner protector container 10 on to the corner of where the head jamb 31 connects to either the hinge jamb 32 or the strike jamb 33 of the frame of the prehung door and frame 30 . All parts 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 and 20 are rectangular having square comers as defined by their edges and fold lines. Ties 15 a and 2 a axe preferably rectangular with tapered or rounded upper edges to facilitate insertion into the envelope 25 formed when fold under flap 19 is folded under second jamb panel 18 . The length of the outside edge of container first side wall 12 , fold line 12 a, 13 , fold line 14 a and fold line 15 b are all about the same L 1 . Fold line 17 b, 20 b and the outside edge of door side panel 20 all have the same length L 2 , said L 2 is longer than L 1 so that when the container corner protector 10 is folded a jamb channel 23 is formed along the top edges of wall 13 , 14 and fold line 15 c. The embodiment in FIG. 2 shows key slots and keys to secure the bottom and fold under flap. Other means of securing such as tape, adhesives, staples and the like can be used.
[0126] The container 22 is formed by folding container first side wall 12 along fold line 12 a perpendicular to container back wall 13 . Container back wall 13 is folded along fold line 14 a perpendicular to container second side wall 14 so the front edge of container first side wall 12 touches the inside of the container front wall 15 . When so folded the face of first side wall 12 faces the inside wall of jamb panel 17 forming a second jamb channel 24 . Width W 1 and W 3 are preferably no greater than the depth of the cavity 39 (edge of jambs to the face of the door 34 or stops 37 whichever is less).
[0127] To assemble the corner protector container 10 and attach it to the cavity 39 side of the prehung door and frame assembly 30 frame the fold under flap 19 is folded 180 degrees along 19 b and 18 a, onto second jamb panel 18 and secured by key 19 a sliding into key slot 17 a. This fold forms an envelope 25 into which ties 15 a and 20 a are later inserted to lock the corner protector container 10 onto the head jamb 31 and either the hinge jamb 32 or the striker jamb 33 of the prehung door and frame assembly 30 .
[0128] The formed second jamb 18 & 19 is then folded along fold line 17 c until perpendicular to jamb panel 17 . Door side tie 20 a is then folded along fold line 20 c and tie 15 a is folded along fold line 15 c until perpendicular to jamb panel 17 .
[0129] Door side panel 20 is then folded along fold line 20 b until perpendicular to jamb panel 17 . Door side tie 20 a is slid into the newly formed envelope 25 formed between second jamb panel 18 and fold under flap 19 .
[0130] Container 22 is formed by folding container bottom 16 along fold line 16 b until perpendicular to container front wall 15 . Bottom flap 21 is folded along fold line 16 c until perpendicular to contain bottom 16 and container first side wall 12 is folded along fold line 12 a until perpendicular to container back wall 13 .
[0131] Locking key 13 a is then folded perpendicular to container back wall 13 . Next the container back wall 13 is folded along fold line 14 a until perpendicular to container second side wall 14 and container second side wall 14 is folded along fold line 15 b until perpendicular to container front wall 15 . Locking key 13 a is then inserted into key slot 16 a. There is formed container 22 having an opening at the top of folded 12 , 13 and 14 . The opening is where hardware or the like can be placed into the container 22 . The opening abuts against the inside of the jamb when the corner protector container 10 is secured at the corner of the frame.
[0132] The final assembly is formed by placing desired contents into newly formed container 22 and then placing corner protector container 10 over the corner formed by the jambs of the prehung door and frame assembly 30 using the channels 23 and 24 formed by the folding process. The container front wall 15 is then folded along fold line 17 b until perpendicular to jamb panel 17 , sliding tie 15 a into the envelope 25 formed by 18 and 19 which locks the corner protector container 10 around the corner formed by the jambs of the prehung door and frame assembly 30 .
[0133] FIG. 7 illustrates an intermediate stage of folding of corner protector container 10 .
[0134] Referring to FIGS. 8-13 , the container embodiment 100 is formed from a unitary, planar rectangular paperboard blank 110 , ( FIG. 8 ) or another embodiment of a blank 210 shown in FIG. 13 .
[0135] Blank 110 includes a container first side wall 111 connected by a fold line 111 a to container back wall 112 . In the embodiment shown in FIG. S the container back wall 112 has first locking key 112 a extending from near the center of its lower edge along fold line 112 c. The container back wall 112 has a second locking key 112 b extending from near the center of upper edge along fold line 112 d. The container back wall 112 is connected by a fold line 113 a to container second side wall 113 . The container second side wall 113 is connected by a fold line 114 a to a container front wall 114 . Extending from the bottom of the container front wall 114 and connected by a fold line 114 c is container bottom 115 . Extending from the bottom edge of container bottom 115 through fold line 115 b is bottom flap 119 . A key slop 115 a is centrally located along fold line 115 b for receiving the locking key 12 a when forming the container embodiment 100 . Extending from the top edge of the container front wall 114 and connected thereto by fold line 114 b is a container top 116 . Extending from the top edge of the container top 116 through fold line 116 b is a top flap 120 . A slot 116 a is centrally formed along the fold line 116 b for receiving the locking key 112 b when forming the container embodiment 100 . The container bottom 115 has a width W 4 shown here as starting along fold line 114 a about equal to the width W 2 of the container back wall 112 and less than the width W 5 of container front wall 114 . The container bottom 115 has a length L 3 and the container top 116 has a length L 4 equal to the width W 1 of the container first side wall 111 which has about the same width W 3 as the container second side wall 113 . The bottom flap 119 and the top flap 116 have about the same width W 4 as the container bottom 115 and the container top 116 (which is also about equal to W 4 ) and a length no longer than the length L 3 and L 4 of the container bottom 115 and container top 116 . Connected to container front wall 114 by fold line 117 a is a jamb panel 117 . Connected to the jamb panel 117 through fold line 117 b is door side panel 118 . The width W 6 of jamb panel 117 is about the same as width of the jambs making up the frame of the prehung door and frame assembly 30 . The length L 2 of the jamb panel 117 and door side panel 118 and the fold line 117 b is preferably the same as, or as shown in FIG. 8 , is greater than L 1 . The width W 5 is greater than width W 2 . When folded the additional length forms a jamb channel 123 between, the first side wall 111 and jamb panel 117 in the container embodiment 100 . The bottom edge of 111 , 112 , 113 , and fold lines 111 a, 113 a, 114 a, 114 b 114 c and 117 a are aligned in a straight line. The width W 7 of the door side panel 118 can vary. All parts 111 , 112 , 113 , 114 , 115 , 116 , 117 , and 118 are rectangular having square corners as defined by their edges and fold lines. Width W 7 of the door side panel 118 is preferably at least about the same as the thickness of the jamb members of the frame. The length of the outside edge of container first side wall 111 , fold line 111 a, fold line 113 a, fold line 114 a and 117 a are all the same, i.e. L 1 . Fold line 117 b and the outside edge of door side panel 118 all about the same length L 2 and said L 2 is preferably longer than L 1 . Key locks 112 a and 112 b and key slots 115 a and 116 a are illustrated as the means for securing the container top 116 and container bottom, however, other means of securing can be employed such as for example, tape, adhesives, staples or the like.
[0136] The container 121 is formed by folding container first side wall 111 along fold line 111 a perpendicular to container back wall 112 . Container back wall 112 is folded along fold line 113 a perpendicular to container second side wall 113 so the front edge of container first side wall 111 touches the inside of the container front wall 114 . When so folded the lace of first side wall 111 faces the inside wall of jamb panel 117 when folded along fold line 117 a perpendicular to container front wall 114 forming a jamb channel 123 . Container bottom 115 is folded perpendicular to container front wall 114 along fold line 114 c and bottom flab 119 is folded perpendicular to container bottom 115 along fold line 115 b and key slot 115 a is engaged with previously folded container back wall 112 and first locking key 112 a. Container top 116 is folded perpendicular along fold line 114 b to front wall 114 to face container bottom 115 . Top flap 120 is folded perpendicular to container top 116 and key slot 116 b is engaged with second locking key 112 b.
[0137] To assemble the container 121 and attach to the frame and into the cavity 39 side of the prehung door assembly 30 frame, the contents of the container are placed inside the container either before the container top 116 or the container bottom 115 are secured (or the container can be filled through the first side wall 111 before it is closed). The container is then placed into the cavity 39 with the container first wall 111 snug against the inside surface of one of the jambs. The jamb panel 117 is then folded perpendicular along fold line 117 a, to form the jamb channel 123 , so that the inside surface of jamb panel fits flush with the outside surface of the frame jamb. Door side panel 118 is then folded along fold line 117 b perpendicular to jamb panel 117 to fit flush with the door side edge of the jamb and secured in place with glue, staple, or banding. In one embodiment the container embodiment 100 is employed with a standard jamb corner protector 122 as shown in FIGS. 11 and 12 such that the standard jamb corner protector holds the container embodiment 100 in place.
[0138] FIGS. 9 and 10 illustrate the container embodiment 100 in various stages of folding before
[0139] being attached to a jamb so the container 121 sits in the inside of cavity 39 . When attached the size of the container depth wise (W 1 and W 3 ) is preferably no greater than the depth of the cavity 39 so the container front wall 114 is essentially the same or less than the depth of the cavity.
[0140] FIG. 13 illustrates another embodiment of a blank 210 for preparing a container 100 . Blank 210 includes a container first side wall 211 connected by a fold line 211 a to container back wall 212 . The container back wall 212 is connected by a fold line 213 a to container second side wall 213 . The container second side wall 113 is connected by a fold line 114 a to a container front wall 214 . Extending from the bottom of the first side wall 211 and connected by a fold line 211 d is container bottom 215 . Extending from the bottom edge of container bottom 215 through fold line 215 b is bottom flap 219 . A key slop 215 a is centrally located along fold line 215 b for receiving the locking key 213 b extending from the bottom edge of second side wall 213 when forming the container embodiment 100 . Extending from the top edge of the second side wall 213 and connected thereto by fold line 213 d is a container top 216 . Extending from the top edge of the container top 216 through fold line 216 b is a top flap 220 . A key slot 216 a is centrally formed along the fold line 216 b for receiving a locking key 211 b extending form the top edge of first side wall 211 when forming the container embodiment 100 . The container bottom 215 and the first side wall 211 have about the same width W 1 . The container bottom 215 has a length L 2 and the container top 216 , L 3 , about equal to the width W 2 of the container back wall 212 . The container second side wall 213 and the container top have about the same width W 3 . The bottom flap 219 and the top flap 220 have about the same width as the width W 1 and W 3 of the first side wall 211 and the second side wall 213 . Connected to the second side wall 213 through fold line 214 a is a front wall 214 . Connected to container front wall 214 through fold line 217 a is a jamb panel 217 . Connected to the jamb panel 217 through fold line 217 b is door side panel 218 . The width W 6 of jamb panel 217 is about the same as width of the jambs making up the frame of the prehung door and frame assembly 30 . The length of the jamb panel 217 and door side panel 218 and the fold line 217 b is preferably the same as, or as shown in FIG. 13 , is greater than L 1 . The width of the front wall 214 , W 5 , is greater than width W 2 of the container back wall 212 . When folded the additional length forms a jamb channel 123 between the first side wall 211 and jamb panel 217 in the container embodiment. The width W 7 of the door side panel 218 can vary. All parts 211 , 212 , 213 , 214 , 215 , 216 . 217 , and 218 are rectangular having square comers as defined by their edges and fold lines. Width W 7 of the door side panel 218 is preferably at least about the same as the thickness of the jamb members of the frame. The length of the outside edge of container first side wall 211 , fold line 211 a, fold line 213 a, fold line 214 a and 217 a are all about the same, i.e. L 1 . Other embodiments of blanks that can make the container embodiment 100 can be similar to that illustrated in FIG. 13 with the location of the container bottom 215 extending from the bottom of second side wall 213 and the container top 216 either extending as shown form the second side wall or from the top of the first side wall with key locks located on the opposite wall. Key locks 112 a and 112 b and key slots 115 a and 116 a are illustrated as the means for securing the container top 116 and container bottom, however, other means of securing can be employed such as for example, tape, adhesives, staples or the like.
[0141] Mirror images of the blanks shown in FIGS. 2, 8 and 13 can also be employed to prepare container and jamb protectors of the present invention.
EXAMPLES
Example 1
[0142] A blank formed from corrugated cardboard was prepared as shown in FIG. 2 and described above.
[0143] The dimensions were: Dimensions are in inches (″).
L 1 —8.75″ L 2 —10.25″ L 3 —3.125″ L 4 —3″ L 5 —3″ W 1 —2″ W 2 —5″
[0151] W 3 —2.25″
W 4 —4.25″ W 5 —5 and 10/16″ W 6 —4 and 14/16″ W 7 —2.75″ W 8 —5″
[0157] The blank was folded and locked onto the corner formed by the perpendicular connection of the head jamb 31 and either the hinge 32 or strike jamb 33 of the frame of a prehung door and frame assembly so the container 22 sat inside the cavity 39 of the door and frame assembly. The jambs of the frame were 4.55 inches wide and 0.675 inches thick. The width of the ties were 2¾ inches and the length along the cut lines were less than L 4 (3″).
Example 2
[0158] A blank formed from corrugated cardboard was prepared as shown in FIG. 8 and described above. The dimensions were: Dimensions ate m inches (″).
L 1 —5″ L 2 —13″ L 3 —2 and ⅛″ L 4 —2 and ⅛″ W 1 —2.25″ W 2 —5″ W 3 —2.25″ W 4 —5″ W 5 —5 and ⅝ ″ W 6 —4.25″ W 7 —2 and ⅛″.
[0170] The blank was folded and locked onto the jamb of a prehung door and frame assembly so the container 121 sat inside the cavity 39 . The jambs of the frame were 4.55 inches wide and 0.675 inches thick.
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A container is provided for shipping hardware such as door knobs, binges, framing wedges and the like with prehung door and frame assemblies. The container has a substantially rectangular configuration having a closed container portion and a jamb panel that extends from the top of the container that wraps around the outside of one of the jambs of the frame to secure the container to the prehung door and frame assembly. The depth of the container is less than the depth of the cavity side of the prehung door and frame assembly and the front wall of the container fits beneath or flush with the edge of the jamb on the cavity side of the frame.
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This is a divisional application of patent application Ser. No. 08/142,575, filed Oct. 25, 1993 U.S. Pat. No. 5,404,626 for METHOD AND APPARATUS TO CREATE AN IMPROVED MOIRE FABRIC BY UTILIZING PRESSURIZED HEATED GAS. Specific reference is being made herein to obtain the benefit of its earlier filing date.
BACKGROUND OF THE INVENTION
This invention relates to a method and apparatus for creation of moire fabric. Traditional moire fabrics are defined as a wavy or watered effect on textile fabric, especially a corded fabric of silk, rayon, or one of the manufactured fibers. An excellent example of a corded fabric would be a faille. Failles are generally defined as having fine, bright, continuous filament warps and coarse spun filling and a plain weave. This creates a noticeable ribbed effect in the filling direction. Other fabrics can be utilized with typically lesser results, however, a visible ribbed effect should be present in the fabric's filling.
Moire fabric falls into one of two categories. The first is an uncontrolled moire when the filling ribs of one layer of fabric are intentionally skewed with respect to the second layer of fabric prior to applying pressure to both layers of fabric. This will result in a significant increase in the number of filling ribs that cross with the associated increase in vertical moire lines. This is very undesirable since the appearance of the moire fabric will never be consistent and will vary from batch to batch. Traditionally, controlled moire fabric is formed by selectively distorting or skewing small portions of the filling ribs so that the filling ribs only cross in selective areas, The most common method is the Francais bar method in which ribbed woven fabric is dragged over a stationary bar which has a series of knobs which are spaced at desired intervals. This is done at very high tension. The knobs distort the filling into a bow wherever they touch the fabric. When two pieces of this fabric are subjected to pressure, a traditional controlled moire will result that is typically found in upholstery, drapery, apparel, and other end uses. Problems with this type of moire patterning include the fact that the pattern is repeatedly fixed and dragging under high tension can damage and/or destroy the fabric.
Another traditional method utilized in creating controlled moire fabric is the "scratch" method. This is accomplished by means of a resilient roll having the desired designs embossed thereon. These designs may include flowers, geometrics, and so forth. While the fabric is in contact with this embossed roll, it is "scratched" with a series of steel blades which distort the filling yarns of the fabric according to the pattern that is embossed on the roll. Upon applying pressure to two pieces of this treated fabric, a moire pattern is produced. Again, there is the problem of the destruction or damage to the yarns by the stool blades and a fixedly repeatable pattern. This "scratch" method produces very poor results with a large quantity of broken filaments. The blades actually only contact the warp yarns thus producing a large amount of broken filaments with only minimal movement of the filling yarn. It is the movement of the filling yarn that is the desired result. Furthermore, by examination of faille fabric, the filling is virtually covered by warp yarns and thus it is very difficult to move the filling by mechanical means. Also, this "scratch" method creates fuzz on the surface of the fabric that results in less shine and poor moire patterns.
Yet another traditional method of producing a controlled moire is by that found in U.S. Pat. No. 2,448,145, which discloses the selective application of water to fabric with a noticeable ribbed effect in the filling direction. The fabric is then placed under high tension and then dried. This will distort the filling yarns in the wet areas differently than the filling yarns in the dry areas. Again, upon applying pressure to two pieces of this treated fabric, a moire pattern is produced. A severe problem with this technology is that it would be very difficult to wet yarns selectively while leaving adjacent yarns dry for a very precise pattern. Furthermore, stretching under high tension can severely weaken or even destroy filling yarns. Furthermore, this method is deficient in that it only works on fibers that absorb large amounts of water such as cotton, silk and so forth. Each pattern requires a specific patterning roll or screen which only changes the pick count slightly in the areas treated with water. While this may produce some beating when the fabrics are sandwiched and calendered, it does not produce true moire because the filling is not distorted with bow or skew.
The present invention solves these problems in a manner not disclosed in the known prior art.
SUMMARY OF THE INVENTION
An apparatus and method for creation of moire fabric by directing at least one stream of pressurized heated gas at the surface of said first piece of overfed fabric to provide lateral yarn displacement and selectively interrupting and re-establishing contact between said stream and said surface in accordance with pattern information in order to pattern said first piece of fabric. This is followed by combining said patterned first piece of fabric with an unpatterned second piece of fabric in overlapping relationship and applying pressure by means of calender rolls having smooth surfaces to said combination of said first piece of patterned fabric and said second piece of unpatterned fabric. By using high pressure heated gas and shrinking some of the thermoplastic yarns, there is movement of the filling yarns in the fabric.
An advantage of this invention is to have moire patterns of any length or, in other words, patterns that do not necessarily repeat.
Still another advantage of this invention is the means of patterning is relatively nondestructive with overfed fabric,
Another advantage of this invention is extremely precise since the amount of shrinking of thermoplastic fibers can be exactly controlled.
A further advantage of this invention is that patterning can be extremely complex with the only limits being those of the human imagination.
Another advantage of this invention is that patterning can be altered while the machine is processing and downloaded in real time with the only limit being that of the complexity of the available computer system utilized in the storage and retrieval of moire patterns.
Yet another advantage of this invention is that the fill yarns can be shifted up to five-eighths of an inch.
In another advantage of this invention is that a perfect fill yarn shift sine wave can be created by contrasting treated portions of textile fabric with untreated portions of textile fabric.
These and other advantages will be in part apparent and in part pointed out below.
BRIEF DESCRIPTION OF THE DRAWINGS
The above as well as other objects of the invention will become more apparent from the following detailed description of the preferred embodiments of the invention when taken together with the accompanying drawings, in which:
FIG. 1 is a schematic side elevation view of apparatus for heated pressurized fluid stream treatment of a moving textile fabric to impart a surface pattern or change in the surface appearance thereof, and incorporating novel features of the present invention;
FIG. 2 is an enlarged partial sectional elevation view of the fluid distributing manifold assembly of the apparatus of FIG. 1;
FIG. 3 is an enlarged broken away sectional view of the fluid stream distributing manifold housing of the manifold assembly as illustrated in FIG. 2;
FIG. 4 is an enlarged broken away sectional view of an end portion of the fluid stream distributing manifold housing;
FIG. 5 is a graph comparing percentage of shrinkage as a function of temperature for a number of fiber types;
FIG. 6 is a diagrammatic side view of two supply rolls, two calendering rolls and two take-up rolls;
FIG. 7 is a photomicrograph (1.1×) of the face of the untreated textile fabric of Example 1;
FIG. 8 is a photomicrograph (1.1×) of the face of the textile fabric of Example 1 after the step of selectively patterning the fabric by means of high pressure streams of heated gas;
FIG. 9 is a photomicrograph (1.1×) of the face of the textile fabric of Example 1 after the step of selectively patterning the fabric by means of high pressure streams of heated gas and the step of calendering under one ton of pressure per linear inch with a second layer of the untreated fabric of FIG. 7;
FIG. 10 is a photomicrograph (1.1×) of the face of the untreated textile fabric of Example 2;
FIG. 11 is a photomicrograph (1.1×) of the face of the textile fabric of Example 2 after the step of selectively patterning the fabric by means of high pressure streams of heated gas;
FIG. 12 is a photomicrograph (1.1×) of the face of the textile fabric of Example 2 after the step of selectively patterning the fabric by means of high pressure streams of heated gas and the step of calendering under one ton of pressure per linear inch with a second layer of the untreated fabric of FIG. 10;
FIG. 13 is a schematic side elevation view of apparatus for laser beam treatment of a moving textile fabric to impart a surface pattern or change in the surface appearance thereof, and incorporating novel features of the present invention; and
FIG. 14 is a diagrammatic side view of a preferred chase-calendering system having a supply roll, two calendering rolls and a take-up roll in which treated fabric is pressed against untreated fabric by the calendering rolls.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the accompanying drawings, and initially to FIG. 1, which shows, diagrammatically, an overall side elevational view of apparatus for heated pressurized gas stream treatment of a textile fabric to impart lateral yarn displacement. As seen, the apparatus includes a main support frame including end frame support members, one of which 10 is illustrated in FIG. 1. Suitably rotatably mounted on the end support members of the frame are a plurality of textile fabric guide rolls which direct an indefinite length of textile fabric 12, from a fabric supply roll 18, past a pressurized heated gas treating unit, generally indicated at 16. After treatment, the textile fabric is collected in a continuous manner on a take-up roll 14, As shown, textile fabric 12 from supply roll 18 passes over an idler roll 36 and is fed by a pair of driven rolls 34, 32 to a main driven textile fabric support roll 26 with the textile fabric 12 between drive roll 32 and textile fabric support roll 26 being overfed and slack in a range of between two and twenty percent with a preferred range of between two and twelve percent. The amount of overfeed depends on the construction, weave tightness, fiber type, and other factors related to the textile fabric 12. The overfeed must stop before the point at which puckering of the textile fabric 12 occurs. The surface of the textile fabric passes closely adjacent to the heated fluid discharge outlet of an elongate fluid distributing manifold assembly 30 of treating unit 16. The treated textile fabric 12 thereafter passes over a series of driven guide rolls 22, 24 and an idler roll 20 to take-up roll 14 for collection.
As illustrated in FIG. 1, fluid treating unit 16 includes a source of compressed gas, such as an air compressor 38, which supplies pressurized air to an elongate air header pipe 40. Header pipe 40 communicates by a series of air lines 42 spaced uniformly along its length with a bank of individual electrical heaters indicated generally at 44. The heaters 44 are arranged in parallel along the length of heated fluid distributing manifold assembly 30 and supply heated pressurized air thereto through short, individual air supply lines, indicated at 46, which communicate with assembly 30 uniformly along its full length. Air supplied to the heated fluid distributing manifold assembly 30 is controlled by a master control valve 48, pressure regulator valve 49, and individual precision control valves, such as needle valves 50, located in each heater air supply line 42. The heaters 44 are controlled in suitable manner, as by temperature sensing means located in the outlet lines 46 of each heater, with regulation of air flow and electrical power to each of the heaters to maintain the heated fluid at a uniform temperature and pressure as it passes into the manifold assembly along its full length.
Typically, for patterning textile fabrics, such as pile fabrics containing thermoplastic yarns, the heaters are employed to heat air exiting the heaters and entering the manifold assembly to a uniform temperature of about 700° F.-750° F. However, the range of temperature for fabric treated with this apparatus may be between about 500° F. to about 1200° F. or more. The preferred operating temperature for any given textile fabric depends upon: the components of the textile fabric, the construction of the textile fabric, the desired effect, the speed of transport of the textile fabric, the pressure of the heated pressurized gas, the tension of the textile fabric, the proximity of the textile fabric to the treating manifold, and others.
The heated fluid distributing manifold assembly 30 is disposed across the full width of the path of movement of the textile fabric and closely adjacent the surface thereof to be treated. Although the length of the manifold assembly may vary, typically in the treatment of textile fabric materials, the length of the manifold assembly may be 76 inches or more to accommodate textile fabrics of up to about 72 inches in width.
Details of the heated fluid distributing manifold assembly 30 may be best described by reference to FIGS. 2-3 of the Drawings. As seen in FIG. 2, which is a partial sectional elevation view through the assembly, there is a first large elongate manifold housing 54 and a second smaller elongate manifold housing 56 secured in fluid tight relationship therewith by a plurality of spaced clamping means, one of which is generally indicated at 58. The manifold housings 54, 56 extend across the full width of the textile fabric 12 adjacent its path of movement.
As best seen in FIG. 2, first elongate manifold housing 54 is of generally rectangular cross-sectional shape, and includes a first elongate gas receiving compartment 81, the ends of which are sealed by end wall plates suitably bolted thereto. Communicating with bottom wall plate through fluid inlet openings, one of which, 83, is shown in FIG. 2, and spaced approximately uniformly therealong are the air supply lines 46 from each of the electrical heaters 44.
The manifold housings 54, 56 are constructed and arranged so that the flow path of gas through the first housing 54 is generally at a right angle to the discharge axes of the gas stream outlets of the second manifold housing 56.
As best seen in FIGS. 2 and 3, manifold housing 54 is provided with a plurality of gas flow passageways 86 which are disposed in uniformly spaced relation along the plate in two rows to connect the first gas receiving compartment 81 with a central elongate channel 88.
Baffle plate 92 serves to define a gas receiving chamber in the compartment 81 having side openings or slots 94 to direct the incoming heated air from the bank of heaters in a generally reversing path of flow through compartment 81. Disposed above channel-shaped baffle plate 92 is compartment 81 between the fluid inlet openings 83 and fluid outlet passageways 86 is an elongate filter member 100 which is a generally J-shaped plate with a filter screen disposed thereabout.
As seen in FIGS. 2, 3 and 4, a second smaller manifold housing 56 comprises first and second opposed elongate wall members, each of which has an elongate recess or channel 108 therein. Wall members are disposed in spaced, coextensive parallel relation with their recesses 108 in facing relation to form upper and lower wall portions of a second gas receiving compartment 110, in the second manifold housing 56. The gas then passes through a third gas receiving compartment 112 in the lower wall member of manifold housing 56 which is defined by small elongate islands 111 approximately uniformly spaced along the length of the member, as shown in FIG. 4. A continuous slit directs heated pressurized air from the third gas receiving compartment 112 in a continuous sheet across the width of the fabric at a substantially right angle onto the surface of the moving textile fabric 12. Typically, in the treatment of textile fabrics such as pile fabrics containing thermoplastic pile yarn or fiber components with a flat woven textile fabric containing thermoplastic or fiber yarn, the continuous slit 115 of manifold 56 may be 0.015 to about 0.030 of an inch in thickness. For precise control of the heated air streams striking the fabric, the continuous slit is preferably maintained between about 0.070 to 0.080 of an inch from the fabric surface being treated. However, this distance from the face of the fabric can be as much as 0.100 of an inch and still produce good pattern definition. The deflecting air tubes are spaced 20 to the inch over the 72 inch air distributing manifold, although apparatus has been constructed as coarse as 10 to the inch and as fine as 44 to the inch.
Second manifold housing 56 is provided with a plurality of spaced gas inlet openings 118 (FIGS. 2 and 3) which communicate with the elongate channel 88 of the first manifold housing 54 along its length to receive pressurized heated air from the first manifold housing 54 into the second gas receiving compartment 110.
The continuous slit 115 of the second manifold housing 56 which directs a stream of air into the surface of textile fabric 12 is provided with tubes 126 which communicate at a right angle to the discharge axis of continuous slit 115 to introduce pressurized cool air, i.e., air having a temperature substantially below that of the heated air in third gas receiving compartment 112, at the heated gas discharge outlet 116 to deflect selectively the flow of heated air through the continuous slit 115 in accordance with pattern control information. Air passing through the tubes 126 may be cooled by a water jacket which is provided with cooling water from a suitable source, not shown, although such cooling is not required.
As seen in FIG. 1, pressurized unheated air is supplied to each of the tubes 126 from compressor 38 by way of a master control valve 128, pressure regulator valve 129, air line 130, and unheated air header pipe 132 which is connected by a plurality of individual air supply lines 134 to the individual tubes 126. Each of the individual cool air supply lines 134 is provided with an individual control valve located in a valve box 136. These individual control valves are operated to open or close in response to signals from a pattern control device, such as a computer 138, to deflect the flow of hot air through continuous slit 115 during movement of the fabric and thereby produce a desired pattern in the fabric. Detailed patterning information for individual patterns may be stored and accessed by means of any known data storage medium suitable for use with electronic computers, such as magnetic tape, EPROMs, etc. The foregoing details of the construction and operation of the manifold assembly 30 of the gas treating apparatus are the subject matter of commonly assigned U.S. Pat. No. 4,471,514 entitled "Apparatus for Imparting Visual Surface Effects to Relatively Moving Material" and issued on Sep. 18, 1984. The disclosure thereof is included herein by reference for full description and clear understanding of the improved features of the present invention.
Each cool air fluid tube 126 is positioned at approximately a right angle to the plane defined by slit 115 to deflect heated pressurized air away from the surface of the moving fabric 12 (FIG. 3) as the textile fabric approaches continuous slit 115. This deflection is generally at about a 45 degree angle from the path defined by continuous slit 115, and serves to direct the deflected heated air toward the oncoming textile fabric 12. Thus, a strong blast of mixed hot and cold air strikes the surface of the textile fabric prior to its being subjected to the action of the heated air issuing from continuous slit 115.
This configuration of tubes 126 provides sufficient volume of air in combination with that from the continuous slit 115 to preheat textile fabric 12 to a temperature preferably short of permanent thermal modification.
It should be noted that, due to the insulation 8 generally surrounding manifold 54, preheating is not believed to be the result of heat radiation from the manifold, but is rather the result of the exposure of textile fabric 12 to the heated air issuing from continuous slit 115, as that air is diverted by the relatively cool air issuing from tubes 126. The heated air used for this purpose is air that has been diverted, in accordance with patterning instructions, after issuing from continuous slit 115, i.e., this air would be diverted whether or not pre-heating was desired. Therefore, preheating of the textile fabric is achieved as an integral part of, and is inseparable from, the patterning process, and requires no additional or separate heated air source. By so doing, not only is a separate preheating step and its attendant complexity unnecessary, but it is believed a separate preheating step would be incapable of imparting heat of sufficient intensity and directivity to maintain the textile fabric 12 at an effective preheated temperature at the instant the heated patterning air issuing from continuous slit 115 contacts the textile fabric, as shown in FIG. 4.
This preheating may cause additional thermal modification during the patterning step. As can be seen in connection with FIG. 5, the amount of shrinkage is a function of the type of fiber involved and the temperature to which it is subjected. The temperature of the hot air is adjusted to accommodate a particular fiber so that the amount of shrinkage can be controlled regardless of the fabric.
Additional information relating to the operation of such a pressurized heated gas apparatus, including more detailed description of patterning and control functions, can be found in coassigned U.S. Pat. No. 5,035,031, that issued on Jul. 30, 1991, which is incorporated by reference as if fully set forth herein and coassigned U.S. Pat. No. 5,148,583, that issued on Sep. 22, 1992, which is incorporated by reference as if fully set forth herein and coassigned U.S. Pat. No. 4,393,562, that issued on Jul. 19, 1983, which is incorporated by reference as if fully set forth herein and coassignod U.S. Pat. No. 4,364,156, that issued on Dec. 21, 1982, which is incorporated by reference as if fully set forth herein and coassigned U.S. Pat. No. 4,418,451, that issued on Dec. 6, 1982, which is incorporated by reference as if fully set forth herein.
In the alternative, another means of achieving lateral yarn displacement, although not the preferred means, is to subject textile fabric to the heat of a laser. Referring now to FIG. 13, which shows, diagrammatically, an overall side elevational view of apparatus for laser treatment of a textile fabric to impart lateral yarn displacement. There is a plurality of textile fabric guide rolls which direct an indefinite length of textile fabric 304, from a fabric supply roll 302, past a laser unit, which is indicated by numeral 320. After treatment, the textile fabric 304 is collected in a continuous manner on a take-up roll 316. As shown, textile fabric 304 from supply roll 302 passes over an idler roll 306 to a main driven textile fabric support roll 308. The surface of the textile fabric 304 is hit by the laser beam from laser unit 320 between idler roll 306 and driven textile fabric support roll 308. The treated textile fabric 304 thereafter passes over a series of driven guide rolls 312, 314 and to take-up roll 316 for collection.
Laser unit 320 is preferable a 10.6 micron wavelength, eighty watt, carbon dioxide laser, although any of a wide variety of lasers will suffice. One typical laser of this type is manufactured by Laser Machining, Inc. that is located at 500 Laser Drive, MS 628, Industrial Park, Somerset, Wis. 54025. Although not specifically limited thereto, the preferred range of moving the textile fabric 304 is a speed of one hundred to two hundred inches per minute.
Referring now to FIG. 6, the next step in the process is to take the patterned textile fabric 216 and have this patterned fabric processed by a calender mechanism that is generally indicated by numeral 201. The patterned textile fabric 216 is placed on supply roll 220 and an unpatterned textile fabric 226 is placed on supply roll 210. Both the patterned textile fabric 216 and unpatterned textile fabric 226 are fed into an upper calendering roll 230 and lower calendering roll 232. For good patterning, both the patterned textile fabric 216 and unpatterned textile fabric 226 should be ribbed since the surface of the upper calendering roll 230 is smooth as well as the surface of lower calendering roll 232. The moire pattern is made by placing these two layers of ribbed textile fabric 216 and 226 on top of each other so that the ribs of the upper unpatterned textile fabric 226 are slightly off-grain in relation to the lower patterned textile fabric 216. These true moire patterns are produced when the upper unpatterned textile fabric 226 is sandwiched with the lower patterned textile fabric 216 and passed through the calender rolls 230 and 232 at high pressure so that wherever the filling yarns cross, a moire pattern is produced. The unpatterned textile fabric 226 may be the lower fabric with the patterned textile fabric 216 being the upper textile fabric with no consequential difference. A pressure of 300 to 10,000 pounds per linear inch of fabric between the upper calendering roll 230 and lower calendering roll 232 on the textile fabrics 216 and 226 causes the ribbed pattern of the patterned textile fabric 216 to be pressed into the unpatterned textile fabric 226 and visa-versa. Pressure requirements for producing moire depend on the speed of traverse, temperature, moisture, and types of calender rolls utilized. A typical range for temperature would be between 100 and 450 degrees Fahrenheit. A typical range for moisture would be between 30 and 100 percent relative humidity for natural fibers. Artificial fibers are typically unaffected by relative humidity. The speed of traverse is typically between 10 and 100 feet per minute.
Flattened areas in the ribs reflect more light and create a contrast to unflattened areas. The patterned textile fabric 216 and unpatterned textile fabric 226 are then received by take-up rolls 250 and 240, respectively. The crushed and uncrushed portions of either textile fabric 216 or fabric 226 causes a difference in light reflectance. This creates a wavy or watery effect in both textile fabrics 216 and 226, respectively. In this case, both textile fabrics 26 and 226 will have the same moire pattern but they will be mirror images. This technique is especially useful when geometric or floral patterns are used. If both textile fabrics 216, 226 are patterned, they would be very difficult to keep in register. The method of treating textile fabric 12 with pressurized heated gas can result in a shift in the fill yarn of up to five-eighths of an inch depending on the fabric fiber, construction, weave, and so forth.
Beat repeat patterns may be introduced by having the pick count different in the two layers of textile fabric 216 and 226 that are sandwiched together. This may be accomplished by weaving two different pick counts. Another way to accomplish this is to place tension on one of the layers which will reduce the pick count slightly to produce a beating. "Beating" is defined as the pattern developed due to superimposed waves of different frequencies.
Textile fabric 226 does not have to be unpatterned and may also be patterned with a different pattern than patterned textile fabric 216. Also, either textile fabric 216 or 226 may have a different pick count to produce a beating pattern. With this embodiment, the preferred material for the upper calendering roll 230 is a metal such as steel and the preferred material for the lower calendering roll 232 is a composite fiber.
The preferred means of calendering is to utilize a chase-type calendering system such as that disclosed in FIG. 14 as opposed to that disclosed in FIG. 6. There is a plurality of textile fabric guide rolls which direct an indefinite length of textile fabric 404, from a fabric supply roll 402, over a series of driven guide rolls 412, 414 and then through calender roll 432. Calender roll 432 is equivalent to calender roll 232 disclosed in FIG. 6. The textile fabric 404 is then fed by a series of driven rolls 442, 4444, and 446 to a main driven textile fabric support roll 448. The surface of the textile fabric passes closely adjacent to the treating unit 450 which may be either a hot gas unit designated in FIG. 1 by numeral 16 or a laser unit designated in FIG. 13 by numeral 320. After treatment, the textile fabric 404 goes around idler roll 460 and then through upper calendering roll 430, which is equivalent to upper calendering roll 230 found in FIG. 6. The moire patterns are produced when the upper treated textile fabric 404 is sandwiched with same lower untreated textile fabric 404 and passed through the calender rolls 430 and 432 at high pressure so that wherever the filling yarns cross, a moire pattern is produced. A pressure of 300 to 10,000 pounds per linear inch of fabric between the upper calendering roll 430 and lower calendering roll 432 on the textile fabric 404 causes a ribbed pattern to be created. A pattern does not appear on the untreated textile fabric 404 due to the fact that the lower calender roll 432 is air cooled so the temperature does not typically exceed 120 degrees Fahrenheit. The speed of traverse is typically between 10 and 100 feet per minute. The textile fabric 404 is then collected in a continuous manner on a take-up roll 462. With this preferred embodiment, the preferred material for the upper calendering roll 230 is a metal such as steel and the preferred material for the lower calendering roll 232 is a lightweight polymer, such as nylon. A typical calendar of this type is manufactured by Ramisch Kleinewefers Kalander GmbH in 1975 located at 415 Krefeld, Postfach 2350, Germany.
Other methods of applying pressure include high pressure rotary presses and platen presses. Some very beautiful textile fabrics are produced by creating the moire fabric and then printing the textile fabric with a colorant such as a dye or pigment. The fabric may, also, be printed first and then patterned by pressurized heated gas and then calendered under pressure to produce a different effect. It may also be patterned by pressurized gas, printed and then calendered to produce a novel textile fabric. Any type of textile fabric printing may be used including but not limited to rotary screen, flat bed, air brush or engraved roll.
Most fiber types will work with this invention including, but not limited to, polyester, polyamide, acetate, rayon, cotton, and so forth. This invention is not restricted to plain weaves but most woven fabrics will work including, but not limited to, dobby and jacquard woven fabrics. Woven fabrics have warp yarns extending in the warp direction and fill yarns extending in the fill direction. For best results, the fill yarns should have a ribbed effect. Furthermore, this invention is not restricted to woven fabrics since a moire pattern can be applied to warp knit fabrics. Warp knit fabrics have wales which are a column of loops lying lengthwise in the fabric and correspond to the warp in woven fabrics. Also, warp knit fabrics have courses which are a row of loops or stitches running across a knit fabric corresponding to filing in woven fabrics.
If approximately fifty percent of the textile fabric is treated by pressurized heated gas and fifty percent of the textile fabric is not treated by pressurized heated gas, then a shift in the fill yarn will be in the form of a sine wave.
The following examples demonstrate, without intending to be limiting in any way, the method by which fabrics of the present invention have been generated.
EXAMPLE 1
An apparatus similar to that schematically depicted in FIGS. 1-4 and 6 was used, in accordance with the following specifications.
Fabric: a faille fabric having a warp comprised of 132 ends/inch of 73.23 denier bright polyester continuous filament and a fill comprised of 7.95 denier spun polyester and a pick count of 33. The faille fabric has been woven, prepared, dyed and heat-set and has a weight of 5.16 ounces per square yard. A photomicrograph of this fabric is shown by FIG. 7 at 1.1 magnification.
This fabric was then patterned with vertical bands utilizing a continuous slit hot air nozzle.
Fluid: hot air, at a pressure of 3.2 p.s.i.g. Pattern gauge: 20 lines per inch.
Source of pattern data: Floppy disk, with appropriate associated electronics of conventional design.
Roll: solid, smooth stainless steel, rotating at a circumference speed of 9 yards per minute in the same direction as warp yarns in fabric.
In this Example, the entire fabric surface was treated in a series of vertical bands. The yarns have been thermally modified by shrinkage where the streams have impacted the fabric. A photomicrograph of this treated fabric is shown by FIG. 8 at 1.1 magnification.
This patterned fabric was then sandwiched with an unpatterned piece of the same fabric and run through a BRIEM® calender at eight yards a minute with a temperature of three-hundred and eighty degrees Fahrenheit on the steel roll with a pressure of one ton per linear inch. The upper roll is made of steel and the lower roll is made of a composite fiber with heat transferred between both rolls. BRIEM® calenders were formerly manufactured by Ernest L. Frank Associates, Inc., 515 Madison Avenue, New York, N.Y. 10022, who is no longer in existence. Both pieces of fabric display the moire pattern shown by the photomicrograph of FIG. 9 at 1.1 magnification.
EXAMPLE 2
An apparatus similar to that schematically depicted in FIGS. 1-4 and 6 was used, in accordance with the following specifications.
Fabric: a faille fabric having a warp comprised of 106 ends/inch of 152.36 denier bright polyester continuous filament and a fill comprised of 13.24 denier spun polyester and a pick count of 31. The faille fabric has been woven, prepared, dyed and heat-set and has a weight of 5.82 ounces per square yard. A photomicrograph of this fabric is shown by FIG. 10 at 1.1 magnification.
This fabric was then patterned with vertical bands with a continuous slit hot air nozzle.
Fluid: hot air, at a pressure of 3.2 p.s.i.g. Pattern gauge: 20 lines per inch.
Source of pattern data: Floppy disk, with appropriate associated electronics of conventional design.
Rolls: solid, smooth stainless steel, rotating at a circumference speed of 9 yards per minute in the same direction as warp yarns in fabric.
In this Example, the entire fabric surface was treated in a series of vertical bands. The yarns have been thermally modified by shrinkage where the streams have impacted the fabric. A photomicrograph of this treated fabric is shown by FIG. 11 at 1.1 magnification. This patterned fabric was then sandwiched with an unpatterned piece of the same fabric and run through a BRIEM® calender at eight yards a minute with a temperature of three-hundred and eighty degrees Fahrenheit on the steel roll with a pressure of one ton per linear inch. The upper roll is made of steel and the lower roll is made of a composite fiber with heat transferred between both rolls. Both pieces of fabric display the moire pattern shown by the photomicrograph of FIG. 12 at 1.1 magnification.
As this invention may be embodied in several forms without departing from the spirit or essential character thereof, the embodiments presented herein are intended to be illustrative and not descriptive. The scope of the invention is intended to be defined by the following appended claims, rather than any descriptive matter hereinabove, and all embodiments of the invention which fall within the meaning and range of equivalency of such claims are, therefore, intended to be embraced by such claims.
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An apparatus and method for creation of moire textile fabric. This can be achieved by directing at least one stream of pressurized heated gas at the surface of said first piece of overfed fabric to provide lateral yarn displacement and selectively interrupting and re-establishing contact between said stream and said surface in accordance with pattern information in order to pattern said first piece of fabric. This is followed by combining said patterned first piece of fabric with an unpatterned second piece of fabric in overlapping relationship and applying pressure by means of calender rolls having smooth surfaces to said combination of said first piece of patterned fabric and said second piece of unpatterned fabric. By using high pressure heated gas and shrinking some of the thermoplastic yarns, there is movement of the filling yarns in the fabric.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to European application 14169872.0 filed May 26, 2014, the contents of which are hereby incorporated in its entirety.
TECHNICAL FIELD
[0002] The present disclosure relates to a chamber for housing strands of a stator bar for electric machines.
[0003] The electric machine is in particular a rotating electric machine such as a synchronous generator to be connected to a gas or steam turbine (turbogenerator) or a synchronous generator to be connected to a hydro turbine (hydro generator) or an asynchronous generator or a synchronous or asynchronous electric motor, or also other types of electric machines.
BACKGROUND
[0004] Electric motors or generators have generally a core stator consisting of magnetic thin iron laminations, usually between 0.35 and 0.5 mm thickness, which form the annular assembly. The stator core is usually secured to an external casing, the latter firmly fixed to the machine foundation. The stator core may consist of lamination packets separated by radial ventilation ducts. Other designs can require axial ducts for the same purpose of cooling. On the surface of the stator core, slots are equally spaced, generally having a rectangular shape. The stator winding is laid down in these slots. Typically one or two bars or coils are present in every slot. The rotor is generally coaxial with the stator and is magnetically coupled to the stator. The rotor comprises a rotor body and a rotor winding, the latter generally fixed within rotor slots. The stator winding is generally connected to a 3-phase electric grid, whereas the rotor winding is usually fed by an external source to produce the magnetic field necessary for electromagnetic induction. The rotor speed can be either synchronous or asynchronous with respect to the armature magnetic field. Electrical power is generated from the armature winding. The bars or coils comprise a kernel, which is generally constituted by a plurality of copper strands, each insulated from the others, and an outer layer of insulation which can be specifically designed for high voltages. The stator winding is generally firmly fixed into the corresponding slots by wedges and other means, like lateral, radial wedges, filler strips and resin, to reduce the winding vibrations thus preventing insulation damages and slot discharges. There are several different stator bars technologies, depending mainly on the generator power output. It is differentiated between direct and indirect cooling designs by gas and/or by a cooling medium. The commonly today used cooling medium is de-ionized water. The connection between the stator bars has mainly two tasks, to lead the current and to lead the cooling medium. It is recommended to separate the electrical and hydraulic circuits to increase the bar to bar connection reliability, thus the whole generator reliability. To this end hollow conductors and water boxes from stainless steel have been introduced in which the two current and hydraulic circuits are split. However, today many generator bars still are equipped with hollow conductors from copper and can be replaced with stainless steel solutions only if complete stator rewind will be offered. Moreover, many machines suffer from cooling medium leaks especially if the brazing of some stator bars elements is not done properly or if the special prevent design is not put in place to mitigate design weaknesses. Therefore a solution is required to split both circuits and thus assure the certain water box reliability and tightness. Cooling medium leakage can occur which will lead to reduced cooling capabilities of the stator bars or the cooling medium will start the corrosion of the Cu-hollow conductors, finally leading to a reduced generator lifetime.
SUMMARY OF INVENTION
[0005] It is an object of the invention to provide a reliable chamber for a stator bar of an electric machine.
[0006] This object is solved with the features of the independent claims 1 and 6 .
[0007] These and further aspects are attained by providing a stator bar chamber and a method for manufacturing of a stator bar chamber in accordance with the accompanying claims. The invention discloses a device and method to facilitate the generator manufacturing process of the stator bars with the hollow conductors and mitigate the risk of losing the tightness of the connections between stator bars. The device and method is mainly used in the area of repair of electric machines, where partial windings are replaced and single stator bars are replaced.
[0008] The problem is solved with a stator bar chamber engaging a stator bar in an electric machine, the chamber encompassing a number of hollow conductors in a first straight part of the chamber, a number of hollow conductors in a second tapered part, and a number of hollow conductors and adjacent solid conductors in a third straight part, whereas the first part of the chamber is closed with a ring mounted at the edge of the first part and a nipple adapted to the ring. The problem is further solved with a manufacturing method for a stator bar chamber comprising the steps of arranging a number of hollow conductors in a first straight part of the chamber, arranging the number of hollow conductors in a second tapered part of the chamber, and arranging the number of hollow conductors and adjacent solid conductors in a third straight part of the chamber, closing the first part of the chamber with a ring by mounting the ring at the edge of the first part and adapting a nipple to the ring.
[0009] Advantageously, the ring is made from copper and the nipple is made from stainless steel.
[0010] In a further example of the invention an essential part or the whole part of the first part is brazed in a first brazing zone to thereby electrically connect the hollow conductors and an essential part or the whole part of the third part is brazed in a second brazing zone to thereby create a watertight part.
BRIEF DESCRIPTION OF DRAWINGS
[0011] Further characteristics and advantages will be more apparent from the description of a preferred but non-exclusive embodiment of the chamber, illustrated by way of non-limiting example in the accompanying drawings, in which:
[0012] FIG. 1 shows a perspective sectional view of a part of a stator bar chamber with a connection part for connecting the chamber with other adjacent chambers, and a first, second, and third part of the opened chamber projecting from the connection part;
[0013] FIG. 2 shows a cross-sectional side view of the stator bar chamber with hollow conductors and solid conductors arranged and the first part of the chamber abut by a ring in which a nipple is fitted;
[0014] FIG. 3 shows a cross-sectional side view of the ring and the nipple according to FIG. 2 to be mounted to the chamber according to FIG. 1 and FIG. 2 .
[0015] With reference to the figures like reference numerals designate identical or corresponding parts throughout the several views.
DETAILED DESCRIPTION
[0016] FIG. 1 shows a perspective sectional view of a part of a chamber 10 suitable for encompassing a stator bar 12 in a stator slot of an electric machine. Below a connecting part 20 can be seen for connecting the chamber 10 with other adjacent chambers (not shown). The chambers 10 are designed for housing stator bars 12 which are fitted into slots in a stator of the electric machine. The chamber 10 comprises a first part 1 above the connecting part 20 in the view shown which first part 1 has a cut opening 13 at the rear and an essentially open side in the direction to a second part 2 . The first part 1 has a protruding part 11 protruding along the first part 1 beyond the cut opening 13 . The protruding part 11 is made from copper, the other parts 1 , 2 , 3 may also be made from copper. The first part 1 and the second part 2 of the chamber 10 are manufactured in one-piece. Through the cut opening 13 of the first part 1 several conductors 14 , 16 are to be passed as is described below. The first part 1 has a rectangular shape and lies parallel to the connection part 20 . The second part 2 has a tapered cross-section with a wider cross-section in the direction to a third part 3 . The third part 3 has a rectangular cross-section broader than the first part 1 and is connected with the first part 1 and the second part 2 in one piece. Together the first part 1 , second part 2 , and third part 3 , which parts are divided as shown by the line above the part of the chamber 10 , form a cone. The third part 3 is designed to house a stator bar 12 for a stator of an electric machine.
[0017] FIG. 2 shows a cross-sectional side view of the stator bar chamber 10 similar to FIG. 1 . Here, hollow conductors 14 and solid conductors 16 are placed in the chamber 10 . Hollow conductors 14 are arranged side by side in the first part 1 serving for transporting a cooling medium through the hollow conductors 14 for cooling the stator bars 12 . This means the stator bar 12 is composed of hollow conductors 14 and solid conductors 16 . The hollow conductors 14 reach through the first part 1 for connection to a cooling medium supply (not shown). The hollow conductors 14 are brazed together in the first part 1 in an area of a brazing zone 15 , shown with diagonal dashed and solid lines in FIG. 2 . In the second part of the chamber 10 the hollow conductors 14 fan out and form a trapezoid in this cross-sectional side view. Accordingly, the cross-section of the chamber 10 is bigger at the end distant from the brazing zone 15 at the first part 1 than at the near end. The connection between the cooling medium stator bar chamber 10 or box and the manifolds of hollow conductors 14 in the second part 2 is made out of stainless steel material. The stainless steel assures the high mechanical resistance to the mechanical stresses, high resistance to corrosion as well as resistance to the magnetic field, which is very important in the end winding zones of the generators, where all the generator parts are exposed to the stray complex magnetic field. The second part 2 ends in the third part 3 which is shaped similar to the first part 1 with a rectangular cross-section but with a bigger height. In the third part 3 the hollow conductors 14 project in a direction essentially parallel to the connection part 20 and the first part 1 . The hollow conductors 14 project through a stator bar 12 which is mainly manufactured by solid conductors 16 . The hollow conductors 14 and the solid conductors 16 alternate in the third part 3 in an example of the invention. The hollow conductors 14 and the solid conductors 16 can also have a different distribution, e.g. with a majority of solid conductors 16 . The hollow conductors 14 and the solid conductors 16 of the stator bar 12 within the third part 3 of the chamber 10 are commonly brazed together in a second brazing zone 17 . The conductors 14 , 16 hereby are made from copper which is easily to be brazed. As can be seen in FIG. 2 the stator bar chamber 10 engages the stator bar 12 and surrounds the stator bar 12 completely except at the open side at the right in this view directed away from the chamber 10 . The stator bar 12 is tightly arranged and to be fitted into a slot of the stator. The first part 1 has a protruding part 11 at its edge far from the other parts 2 , 3 . At the left side in FIG. 2 the protruding part 11 has a rectangular shape in the cross-section shown, the protruding part 11 projects along the whole rectangular edge of the first part 1 . The protruding part 11 engages into a ring 5 which is fitted to the chamber 10 in a way to create a tight connection, especially for water. The ring 5 which is in this example made from copper is usually brazed to the first part 1 via the protruding part 11 to establish a solid connection. The ring 5 leaves an opening into which a nipple 7 is fitted. The nipple 7 can be coupled to the chamber 10 without a further connection means, without brazing or similar, in a form closure. An alternative connection method between the copper ring 5 and the stainless steel nipple 7 is brazing. The outer cross-section of the nipple 7 is fit to the inner cross-section of the ring 5 to this end. The nipple 7 has a smaller cylindrical shape in the area of connection to the opening of the ring 5 and a broader shape at the outer end as shown in FIG. 2 . The nipple 7 is further shown in FIG. 3 . The nipple 7 is in one example manufactured from stainless steel. Water tightness is very crucial in generators equipped with the copper hollow conductors 14 , where the link copper to stainless steel elements exist. Therefore, the invention allows the splitting of the electrical and the hydraulic circuit within the bar to bar connection, thus increasing generator parts reliability as well as the reliability of the complete electric machine. The solution discloses an improved stator direct cooled bar-to-bar design, the connection of the stator bars 12 towards each other, and improves the manufacturing process. An example of the stator bar chamber 10 and the method to manufacture is briefly described. The chamber 10 represents a copper water box or chamber 10 together with the bi-metallic composition 8 , which is made of the copper ring 5 and the stainless steel nipple 7 . There are two brazing zones, the first brazing zone 15 and the second brazing zone 17 , which allow the separation of the current circuit from the hydraulic circuit and as well to increase the tightness of the chamber 10 . The inventional chamber 10 described by way of example assures as well that the copper strands of the stator bars 12 will not corrode due to the contact with the cooling medium. The second brazing zone 17 represents the current circuit lead, whereas the first brazing zone 15 assures the tightness of the chamber 10 . The brazing of the ring 5 to the protruding part 11 closes the hydraulic connection of the chamber 10 and the hydraulic connection to the external cooling circuit (not shown), which feeds the cooling medium to the chamber 10 . The external cooling circuit connects several chambers 10 with each other and therewith several stator bars 12 . The external cooling circuit can comprise coolant hoses to transport the cooling medium.
[0018] To avoid that the brazing connection of one of the designed brazing zones 15 , 17 breaks, the brazing process consist of three steps as follows. In the first step the bi-metallic composition 8 is brazed, the copper ring 5 to the stainless steel nipple 7 . In the second step the conductors of the stator bar 12 , commonly made from solid copper strands and a copper hollow conductor 14 , are brazed to the chamber 10 simultaneously. In the last third step the nipple 7 is brazed to the protruding part 11 of the first part 1 of the chamber 10 . Due to the presented improved chamber 10 and bi-metallic composition 8 and the proposed sequence of brazing, the risk of de-braze of the copper conductors 14 , 16 of the stator bar 12 from the chamber 10 is reduced. Furthermore, the corrosion of copper strands of the stator bar 12 is mitigated due to the fact that the electrical circuit and the hydraulic circuit are separated. The solution described here presents the improvement of the chamber 10 , also referred to as cooling medium box, to cool a stator bar 12 with the bi-metallic composition 8 , applicable to the stator bars 12 with copper hollow conductors 14 . Thus, generator life time and reliability is increased.
[0019] FIG. 3 shows a cross-sectional side view of the ring 5 and the nipple 7 according to FIG. 2 to be mounted to the chamber according to FIG. 1 and FIG. 2 . Shown is the connection of the nipple 7 made from stainless steel to the ring 5 from copper for example. A connection of copper and stainless steel is hard to establish due to the different chemical composition of both materials. If the connection of copper with stainless steel is not properly done the cooling chamber 10 will lose its tightness and corrosion of the chamber 10 will occur leading to a reduced generator, parts lifetime. The chamber 10 is hereby not fabricated from stainless steel which means a reliable braze connection between the part 11 and the ring 5 can be established.
[0020] While the invention has been described in detail with reference to exemplary embodiments thereof, it will be apparent to one skilled in the art that various changes can be made, and equivalents employed, without departing from the scope of the invention. The foregoing description of the preferred embodiments of the 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 form disclosed, and modifications and variations are possible in light of the above teachings or may be acquired from practice of the invention. The embodiments were chosen and described in order to explain the principles of the invention and its practical application to enable one skilled in the art to utilize the invention in various embodiments as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the claims appended hereto, and their equivalents. The entirety of each of the aforementioned documents is incorporated by reference herein.
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The present disclosure relates to a chamber for housing strands of a stator bar for electric machines.
The problem to provide a reliable chamber for a stator bar of an electric machine is solved with a stator bar chamber engaging a stator bar in an electric machine. The chamber includes a number of hollow conductors in a first straight part of the chamber, a number of hollow conductors in a second tapered part, and a number of hollow conductors and adjacent solid conductors in a third straight part. The first part of the chamber is closed with a ring mounted at the edge of the first part and a nipple adapted to the ring.
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BACKGROUND
[0001] The present disclosure relates to medical implants. More particularly, the present disclosure relates to medical implants having a mesh configuration that are useful in tissue repair.
[0002] Implantable meshes may be inserted into a patient's body during a surgical procedure to reinforce, at least temporarily, deficient musculo-aponeurotic substrates.
[0003] For example, implantable meshes may be utilized to treat hernias, urinary incontinence, uterovaginal prolapses, and other similar injuries.
[0004] Implanted meshes may be produced from non-absorbable or absorbable materials and may be constructed of monofilament threads or multifilament yarns. Some commercially available implantable meshes are made of monofilaments threads, the resulting mesh having relatively small pores, in some cases less than about 1 mm, and almost all are relatively rigid. This rigidity results in a mechanical mismatch between the implant and the host tissues which, in turn, may result in irritation of the tissue at the site of the implant. This irritation, combined with a lack of porosity, may lead to the formation of a pseudo fibrous capsule around the mesh implant which may cause discomfort, chronic pain, and increase the risk of recurrence.
[0005] Recently, some monofilament polypropylene meshes have been demonstrated to be oxidized in vivo when infection or acute inflammation occurs, resulting in some degradation of the material which could also be responsible for mesh stiffening, impaired abdominal wall movement when used to repair a hernia, and chronic pain.
[0006] Multifilament meshes are usually softer and more compliant than monofilament meshes. A multifilament mesh may possess a larger, more developed surface, which could be beneficial with respect to tissue integration, but could be detrimental with respect to increased bacterial contamination.
[0007] One way to attempt to minimize the risk of infection associated with the use of meshes in vivo is to apply antimicrobial coatings thereto. For example, U.S. Patent Application Publication No. 2005/0085924 and U.S. Pat. No. 5,217,493 both disclose meshes with coatings possessing antimicrobial agents. However, while these meshes may exhibit an antibacterial effect on a local and diffuse basis by inhibiting bacterial adhesion and proliferation as a result of the antibiotics and antiseptics included in the coatings, they may also damage the cytocompatibility of the material, thereby inhibiting and/or delaying the integration of the mesh with tissue. This inhibition or delay of the integration of the mesh material may generate adverse effects such as local necrosis, seroma, pseudocapsule formation, secondary infection, and the like.
[0008] Meshes with long term biocompatibility and infection resistance remain desirable.
SUMMARY
[0009] The present disclosure provides mesh implants which are tissue-friendly, with an initial rigidity providing easy handling and positioning of the mesh. In embodiments, the mesh implants may possess biological active agents capable of providing the mesh with desirable properties during the key phase of tissue integration, while maintaining for the long term a minimal amount of material possessing suitable mechanical properties. The strands of the mesh may include monofilament threads or multifilament yarns.
[0010] In embodiments, a suitable medical implant may include a mesh having strands and pores, with a coating on at least a portion of the mesh. The coating on the mesh, in embodiments, may include at least one collagen in combination with at least one polysaccharide which, in turn, may include fucans, dextrans, dextran derivatives, chitosan, cellulose, oxidized cellulose, polyglucuronic acid, hyaluronic acid and combinations thereof.
[0011] In other embodiments, a medical implant of the present disclosure may include a mesh having strands and pores and a coating on at least a portion of the mesh, wherein the coating includes at least one collagen in combination with at least one fucan.
[0012] In some embodiments, the strands of the mesh may include a synthetic non-absorbable material such as polyethylene, polypropylene, copolymers of polyethylene and polypropylene, blends of polyethylene and polypropylene, polyethylene terephthalate, polyamides, aramides, expanded polytetrafluoroethylene, polyurethane, polyvinylidene difluoride, polybutester, copper alloy, silver alloy, platinum, medical grade stainless steel, and combinations thereof.
[0013] Methods for forming such meshes and uses thereof are also provided.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] Various embodiments of the present disclosure will be described herein below with reference to the figures wherein:
[0015] FIG. 1 is a graph of the results of HPLC analysis depicting the amount of fucan released from a collagen film in accordance with the present disclosure;
[0016] FIG. 2 is a graph depicting the adhesion of S. aureus on collagen and collagen-fucan films in accordance with the present disclosure (a), and adhesion of S. aureus on polypropylene (PP, T′), collagen films, and collagen-fucan films in the presence of an extract obtained from a collagen-fucan film in accordance with the present disclosure (b);
[0017] FIG. 3 is a graph depicting the growth of fibroblasts on polypropylene (PP), polyethylene terephthalate (PET), collagen films with varying concentrations of fucan, and collagen films with varying concentrations of fucan on a textile;
[0018] FIG. 4 is a depiction of a Boyden Chamber Assay utilized to test coated implants of the present disclosure;
[0019] FIG. 5 is a graph depicting the chemotactic response of fucans on fibroblasts (varying concentrations of fucan in collagen films, with and without textile, with polypropylene and polyethylene terephthalate as a control);
[0020] FIG. 6 is a graph depicting the anti-complement activity of heparin, fucan precursor P240 RED, and fucan TH90RED A2 0305 PUF 30 in solution; and
[0021] FIG. 7 are histological pictures obtained after intraperitoneal implantation of implants of the present disclosure in rats at various times after explantation.
DETAILED DESCRIPTION
[0022] According to the present disclosure there is provided a surgical mesh implant made of a biocompatible material. The mesh implants of the present disclosure may be suitable for soft tissue repair, for example when a permanent reinforcement is necessary. The implants of the present disclosure can also be used as an in-vitro support for biological evaluations, for example, cell cultures, microbiological assays, anticomplement and anticoagulant activity assays, and the like.
[0023] To support tissue ingrowth, it may be desirable to minimize the invasiveness of a mesh implant. At the same time, while it may be desirable for the implant to possess mechanical properties as close as possible to those of healthy tissue, the stiffer the mesh, the easier for the surgeon it is to handle the mesh, to spread it homogeneously on the defect, and adhere the mesh to the defect, thus decreasing the time required for a surgical procedure to repair a defect. Thus, a suitable mesh implant in accordance with the present disclosure may possess large pores, a limited amount of permanent, non-absorbable material, and isoelastic behavior. The mesh of the present disclosure may also, in embodiments, possess a coating which enhances its integration in vivo while at the same time minimizing bacterial colonization of the mesh. Such a coating may also, in embodiments, provide a stiffness to the mesh thereby facilitating its handling by a surgeon during implantation.
[0024] The mesh implant of the present disclosure may be made of strands which, in turn, may be made of filaments of any suitable biocompatible material. Suitable materials from which the mesh can be made should have the following characteristics: biocompatibility; sufficient tensile strength; sufficiently inert to avoid foreign body reactions when retained in the human body for long periods of time; exhibit minimal allergic and/or inflammatory response; non-carcinogenic; easily sterilized to prevent the introduction of infection when the mesh is implanted in the human body; minimal elasticity; minimal shrinkage; and easy handling characteristics for placement in the desired location in the body. Meshes of the present disclosure may be of monofilament or multi-filament in construction.
[0025] In some embodiments the filaments may be made of a plastic or similar synthetic non-absorbable material. Some examples of suitable non-absorbable materials which may be utilized include polyolefins, such as polyethylene, polypropylene, copolymers of polyethylene and polypropylene, and blends of polyethylene and polypropylene. Other non-absorbable materials which may be utilized include polyesters such as polyethylene terephthalate (PET), polyamides, aramides, expanded polytetrafluoroethylene, polyurethane, polyvinylidene difluoride (PVDF), polybutester, copper alloy, silver alloy, platinum, medical grade stainless steels such as 316L medical grade stainless steel, combinations thereof, and the like. Examples of commercially available polypropylene-based textile supports which may be utilized include those sold under the brand name PARIETENE® from Sofradim, and examples of commercially available PET-based textile supports which may be utilized include those sold under the brand name PARIETEX® from Sofradim.
[0026] In other embodiment the filaments of the mesh may be made of an absorbable material. Suitable absorbable materials include, but are not limited to, trimethylene carbonate, caprolactone, dioxanone, glycolic acid, lactic acid, glycolide, lactide, homopolymers thereof, copolymers thereof, and combinations thereof. Specific absorbable materials which may be suitable include, for example chitosan, cellulose, oxidized cellulose, combinations thereof, and the like.
[0027] In embodiments, the filaments described above may be utilized to form strands which, in turn, may be utilized to form a mesh implant of the present disclosure. For example, the strands may be warp knit or woven into a variety of different mesh shapes. Thus, the mesh may include strands, with pores formed between the strands. In some embodiments the strands may be arranged to form a net mesh which has isotropic or near isotropic tensile strength and elasticity.
[0028] The monofilaments utilized to produce the strands of the mesh implant may have a diameter of from about 0.07 mm to about 0.1 mm, in embodiments from about 0.08 mm to about 0.09 mm.
[0029] In embodiments, a mesh implant of the present disclosure may possess large hexagonal pores of more than about 1.5 mm in size, in embodiments from about 1.5 mm to about 4 mm in size. In some embodiments, the pores in a mesh implant in accordance with the present disclosure may be square in shape having dimensions of from about 1.2 mm to about 2.5 mm in size, in embodiments about 1.5 mm×1.5 mm in size.
[0030] A yarn in accordance with the present disclosure may possess a mass in grams per 10,000 meters (decitex or dtex) of from about 33 dtex to about 76 dtex, in embodiments from about 35 dtex to about 50 dtex.
[0031] As would be apparent to one of skill in the art, the surface density of a mesh can be decreased while maintaining its mechanical properties in an adequate range by selecting a monofilament thread having the right size and strength. For example, for a thread having the same diameter, a PET monofilament thread may have better mechanical properties compared to a polypropylene monofilament, so a smaller diameter PET monofilament thread can be used to obtain similar mechanical properties as the polypropylene monofilament, thus decreasing the amount of material implanted and enlarging pore sizes. Similarly, in other embodiments a PET monofilament thread having the same diameter as a polypropylene monofilament can be used with a more open textile structure to get similar mechanical properties as the polypropylene monofilament, thus decreasing the amount of material implanted and enlarging pore sizes. In both cases the surface density may not be lower because the PET specific weight is higher than the polypropylene specific weight. However, the developed surface will be lower and the pore size greater, thereby enhancing tissue ingrowth.
[0032] Moreover, for the same yarn count, a high tenacity polyester multifilament yarn may have better mechanical properties than a standard polyester multifilament yarn, so a thinner high tenacity polyester such as a high tenacity PET multifilament yarn could be used to obtain similar mechanical properties, thus decreasing the mesh surface density. A same count high tenacity PET multifilament yarn can be combined with a more open textile structure to get similar mechanical properties, thus decreasing the mesh surface density. In both cases the surface density will be lower, thereby limiting foreign body implantation and promoting mesh integration.
[0033] Mesh implants of the present disclosure may have a surface density of less than about 50 g/m 2 , in embodiments from about 20 g/m 2 to about 50 g/m 2 , in other embodiments from about 25 g/m 2 to about 35 g/m 2 .
[0034] Mesh implants may also possess compliance and mechanical properties matching or very similar to native tissues, for example from about 10% to about 50% of elongation under a force of about 20 N of load in warp and weft direction, in embodiments from about 10% to about 40% of elongation under a force of about 20 N in warp direction and from about 20% to about 50% of elongation under a force of about 20 N in weft direction. Thus, in embodiments, a mesh of the disclosure may possess isoelastic behavior wherein the ratio of longitudinal elastic properties to transverse elastic properties is from about 0.7:1 to about 1.3:1, in embodiments of about 0.75:1 under a force of about 20 Newtons of load.
[0035] The pattern and the density of the strands forming the mesh provide the mesh implant with its necessary strength. Mesh implants in accordance with the present disclosure may possess a tensile strength of more than about 80 Newtons, in embodiments from about 80 Newtons to about 200 Newtons, in other embodiments from about 90 Newtons to about 150 Newtons, as determined according to ISO 13934-1 in both the warp and weft direction.
[0036] The shape of the mesh implant of the present disclosure may be varied depending upon the condition to be treated with the mesh implant. Mesh implants of the present disclosure may be circular, rectangular, trapezoidal, and the like. Due to the variability in patient morphology and anatomy, the implant may be of any suitable size. The mesh implant may have a width from about 50 mm to about 500 mm, in embodiments from about 75 mm to about 200 mm, and a length from about 50 mm to about 500 mm, in embodiments from about 90 mm to about 250 mm.
[0037] The thickness of the surgical mesh of the present disclosure may also vary, but may be less than about 5 mm. In some embodiments, the thickness of the mesh can be from about 0.05 mm to about 0.8 mm.
[0038] In embodiments a mesh may be formed utilizing a polyester monofilament, of a diameter of from about 0.07 mm to about 0.1 mm. In other embodiments, a multifilament polyester may be utilized to form a mesh, with a mass of about 49 dtex. In other embodiments, a multifilament high tenacity polyester, for example, a high tenacity PET, may be utilized to form a mesh, with a mass of about 49 dtex. In either embodiment, the mesh may have a low surface density of from about 20 g/m 2 to about 35 g/m 2 .
[0039] Methods and apparatus suitable for forming meshes are within the purview of those skilled in the art. Suitable apparatus and methods include, for example, those disclosed in U.S. Pat. Nos. 6,408,656 and 6,478,727, the entire disclosures of each of which are incorporated by reference herein. In embodiments, a suitable mesh may be formed utilizing a tricot warp knitting machine or Rachel warp knitting machine with 2 or 3 guide bars. The gauge of needles utilized to form these meshes may be from about E22 to about E28 (i.e., about 22 to about 28 needles/inch), in embodiments from about E22 to about E24, in some embodiments about E24. In some embodiments, a mesh may be formed with two half threaded guide bars, being moved symmetrically for forming an open mesh according to the following graphics/bar movement.
[0040] In embodiments, to obtain pores with no specific shape and several pore sizes:
[0041] Guide-bar BI: 5.4/4.3/2.1/0.1/1.2/3.41//
[0042] Guide-bar BII: 0.1/1.2/3.4/5.4/4.3/2.1//
[0043] or
[0044] Guide-bar BI: 3.2/2.1/0.1//
[0045] Guide-bar BII: 0.1/1.2/3.2//
[0046] In some embodiments, a mesh may be formed with several guide bars using adequate threading diagrams and adequate bar movement to form an open mesh according to the following graphics.
[0047] In embodiments, to obtain single size square pores:
[0048] Guide-bar BI: 1.0/0.1//
[0049] Guide-bar BII: 6.6/0.0/2.2/0.0/6.6/4.4//
[0050] Guide-bar BIII: 0.0/6.6/4.4/6.6/0.0/2.2//
[0051] In other embodiments, to obtain single size hexagonal pores:
[0052] Guide-bar BI: 1.0/0.1/1.0/2.3/3.2/2.3//
[0053] Guide-bar BII: 0.0/1.1/0.0/3.3/2.2/3.3//
[0054] In embodiments, it may be desirable for a mesh to possess single size hexagonal pores, but any configuration of pores, or multiple pore configurations, may be utilized.
[0055] In order to facilitate handling by a surgeon during implantation, the meshes of the present disclosure may possess a coating thereon. Suitable coatings include, but are not limited to, collagens, chitosan, polyethylene glycol (PEG), polyglycolic acid (PGA), oxidized cellulose, polyarylates, polysiloxanes, combinations thereof, and the like.
[0056] In embodiments, a suitable coating may include collagen. The term “collagen” as used herein refers to all forms of collagen from any source including, but not limited to, collagen extracted from tissue or produced recombinantly, collagen analogues, collagen derivatives, modified collagens, and denatured collagens such as gelatin. For example, collagen may be extracted and purified from animal tissue including human or other mammalian sources, such as bovine or porcine corium and human placenta, or may be recombinantly or otherwise produced. The preparation of purified, substantially non-antigenic collagen in solution from animal sources such as bovine and porcine sources is within the purview of those skilled in the art. For example, collagen, including Type I collagen, may be extracted from pig dermis via an acid pH solubilization or via a pepsin digestion and purified with saline precipitations, utilizing processes within the purview of those skilled in the art. Moreover, U.S. Pat. No. 5,428,022 discloses methods of extracting and purifying collagen from the human placenta, and U.S. Pat. No. 5,667,839 discloses methods of producing recombinant human collagen in the milk of transgenic animals, including transgenic cows. Non-transgenic, recombinant collagen expression in yeast and other cell lines is described in U.S. Pat. Nos. 6,413,742, 6,428,978, and 6,653,450.
[0057] Collagen of any type, including, but not limited to, types I, II, III, IV, or any combination thereof, may be used in the coating of a mesh implant of the present disclosure. Either atelopeptide or telopeptide-containing collagen may be used; however, when collagen from a xenogenic source, such as bovine collagen or porcine collagen, is used, atelopeptide collagen may be suitable because of its reduced immunogenicity compared to telopeptide-containing collagen.
[0058] Collagen that has not been previously crosslinked by methods such as heat, irradiation, or chemical crosslinking agents may be utilized in some embodiments; in other embodiments previously crosslinked collagen may be used.
[0059] Collagens for use in coatings of mesh implants of the present disclosure may generally be in aqueous suspensions at a concentration of from about 20 mg/ml to about 120 mg/ml, in embodiments from about 30 mg/ml to about 90 mg/ml.
[0060] Collagen for use in forming a coating on a mesh implant of the present disclosure may be fibrillar or nonfibrillar. Collagens for use in the compositions of the present invention may start out in fibrillar form, then can be rendered nonfibrillar by the addition of one or more fiber disassembly agent(s). Where utilized, a fiber disassembly agent may be present in an amount sufficient to render the collagen substantially nonfibrillar at a pH of about 7. Suitable fiber disassembly agents include, without limitation, various biocompatible alcohols, amino acids, inorganic salts, and carbohydrates. Suitable biocompatible alcohols include glycerol and propylene glycol. Suitable amino acids include arginine. Suitable inorganic salts include sodium chloride and potassium chloride.
[0061] In embodiments, collagen type I and/or collagen type III, the main molecules of native extracellular matrix (ECM), may be utilized as the coating. Collagen types I and III are known to facilitate cellular adhesion, proliferation and differentiation.
[0062] The collagen coating leaves the pores empty for rapid colonization of the macrostructure of the mesh. Hence, the coating of the present disclosure should provide a better handling of the mesh and will also hide the main part of the surface of the synthetic yarns utilized to construct the mesh during the early integration phase.
[0063] In some embodiments, in addition to the collagen described above, a coating on a mesh implant of the present disclosure may also include additional absorbable materials. Such additional absorbable materials are within the purview of those skilled in the art and include, but are not limited to, trimethylene carbonate, caprolactone, dioxanone, glycolic acid, lactic acid, glycolide, lactide, polysaccharides including but not limited to, chitosan, polyglucuronic acid, hyaluronic acid, homopolymers thereof, copolymers thereof, and combinations thereof. When present, such absorbable materials may be present in a coating in an amount from about 20% to about 80% by weight of the coating, in embodiments from about 40% to about 60% by weight of the coating.
[0064] The coating of the present disclosure, in embodiments, may also include a bioactive molecule, such as a natural vegetal or synthetic polysaccharide. Suitable natural or synthetic polysaccharides include fucans, also called fucoidans, dextrans, dextran derivatives, cellulose, oxidized cellulose, chitosan, polyglucuronic acid, hyaluronic acid, combinations thereof, and the like.
[0065] In embodiments, a fucan may be utilized as the polysaccharide in the coating of a mesh implant of the present disclosure. As used herein, “fucan” includes any natural fucoidans, including those produced by recombinant techniques, as well as any fucoidan precursors, fucoidan derivatives or modified fucoidans and fucoidan derivatives, and depolymerized fucans. “Fucan” and “fucoidan” are used interchangeably herein. Sulfated fucans, also referred to simply as fucans, include natural sulfated polysaccharides extracted from the cell wall of brown algae, or the egg jelly coat of sea urchins, or from the body wall of sea cucumbers. Fucoidans are mainly absent from green algae ( Chlorophyceae ), red algae ( Rhodophyceae ), golden algae ( Xanthophyceae ) and from fresh water algae and terrestrial plants. In embodiments, suitable fucans may be extracted from brown algae. Suitable fucans include, for example, TH90RED A2 0305 PUF30 (extracted from Ascophyllum Nodosum brown algae) which is a low molecular weight fucan of about 17,000 g/mol with a polydispersity index of about 1.78.
[0066] Methods for extracting fucans from natural vegetal sources, including brown algae, are within the purview of those skilled in the art. Once obtained, the fucan may then be combined with collagen as described above to form a coating on a mesh implant of the present disclosure.
[0067] The addition of a fucan as part of a coating may permit quicker integration of the mesh in host tissue by enhancing fibroblastic and mesothelial cell proliferation and migration (respectively an increase of about 45% to 70% and about 50% to 80% of stimulation), inhibiting bacterial adhesion proliferation (about 20% to 40% of inhibition) and generating a favorable environment after implantation as evidenced by reduced anticomplement, limiting the immune response of the host, reducing anticoagulant activity, and enhancing the integration of the mesh without generating any adverse hemophilic effect. Biological properties of the fucans may be increased with a low molecular weight, low polydispersity index and a high sulfate rate.
[0068] A coating of the present disclosure may possess collagen in an amount from about 2% to about 5% by weight of the coating solution, in embodiments from about 2.5% to about 3.2% by weight of the coating solution, with a polysaccharide like a fucan present in the coating in an amount from about 0.001% to about 1% by weight of the coating solution, in embodiments from about 0.005% to about 0.05% by weight of the coating solution.
[0069] As noted above, in embodiments the collagen may be in a suspension. The polysaccharide described above may be added to this suspension which, in turn, may then be applied to a mesh implant. In other embodiments the collagen and polysaccharide may be placed into a solvent to form a solution, which may then be applied to a mesh. Any biocompatible solvent may be used to form such a solution. In embodiments, suitable solvents include, but are not limited to, methylene chloride, hexane, ethanol acetone, combinations thereof, and the like.
[0070] The coating may encapsulate an entire filament, strand or mesh. Alternatively, the coating may be applied to one or more sides of a filament, strand or mesh. Such a coating may improve the desired therapeutic characteristics of the mesh.
[0071] The coating may be applied to the mesh implant utilizing any suitable method known to those skilled in the art. Some examples include, but are not limited to, spraying, dipping, layering, calendaring, etc.
[0072] In some embodiments, the coating may add bulk to the mesh such that it is easier to handle. As the coating includes collagen and a polysaccharide, the coating should be released into the body after implantation and therefore should not contribute to the foreign body mass retained in the body. Thus, the advantages of a surgical implant having minimal mass may be retained.
[0073] The coating may be released into the body within a period of time from about 0 days to about 28 days following implantation, in embodiments from about 1 day to about 5 days following implantation.
[0074] As noted above, in embodiments a mesh implant in accordance with the present disclosure may possess initial handling properties which facilitate surgeon use, including use through a laparoscopic approach. Such handling properties may include, for example, initial memory, relative stiffness, surface smoothness, and combinations thereof.
[0075] Mesh implants of the present disclosure may also possess a tissue friendly surface capable of enhancing quick cellular adhesion, proliferation and connective tissue differentiation, while minimizing foreign body inflammation and decreasing the risk of bacterial adhesion and proliferation.
[0076] In embodiments, the mesh implant of the present disclosure may possess additional bioactive agents in its coatings. The term “bioactive agent”, as used herein, is used in its broadest sense and includes any substance or mixture of substances that have clinical use. Consequently, bioactive agents may or may not have pharmacological activity per se, e.g., a dye. Alternatively, a bioactive agent could be any agent which provides a therapeutic or prophylactic effect; a compound that affects or participates in tissue growth, cell growth, and/or cell differentiation; a compound that may be able to invoke a biological action such as an immune response; or a compound that could play any other role in one or more biological processes.
[0077] Any agent which may produce therapeutic benefits, i.e., tissue repair, cell proliferation, limit the risk of sepsis, may be added in the coating formulation. Such agents include, for example, fucans, dextrans, dextran derivatives, carrageenan, alginate, hyaluronic acid, keratin sulfate, keratan sulfate, dermatan sulfate, chitin, chitosan, combinations thereof, and the like. For example, chitosan is biodegradable, has good biocompatibility, has been demonstrated to be hemostatic and bacteriostatic, and it also plays an important role in cell proliferation and tissue regeneration.
[0078] Examples of classes of bioactive agents which may be utilized in accordance with the present disclosure include antimicrobials, analgesics, antiadhesive agents, antipyretics, anesthetics, antiepileptics, antihistamines, anti-inflammatories, cardiovascular drugs, diagnostic agents, sympathomimetics, cholinomimetics, antimuscarinics, antispasmodics, hormones, growth factors, muscle relaxants, adrenergic neuron blockers, antineoplastics, immunogenic agents, immunosuppressants, gastrointestinal drugs, diuretics, steroids, lipids, lipopolysaccharides, polysaccharides, and enzymes. It is also intended that combinations of bioactive agents may be used.
[0079] Suitable antimicrobial agents which may be included as a bioactive agent in the coating include quaternary ammonium, including triclosan also known as 2,4,4′-trichloro-2′-hydroxydiphenyl ether, diallyldimethylaminocarbonate (also known as DADMAC), chlorhexidine and its salts, including chlorhexidine acetate, chlorhexidine gluconate, chlorhexidine hydrochloride, and chlorhexidine sulfate, silver and its salts, including silver acetate, silver benzoate, silver carbonate, silver citrate, silver iodate, silver iodide, silver lactate, silver laurate, silver nitrate, silver oxide, silver palmitate, silver protein, and silver sulfadiazine, polymyxin, tetracycline, aminoglycosides, such as tobramycin and gentamicin, rifampicin, bacitracin, neomycin, chloramphenicol, miconazole, quinolones such as oxolinic acid, norfloxacin, nalidixic acid, pefloxacin, enoxacin and ciprofloxacin, penicillins such as oxacillin and pipracil, nonoxynol 9, fusidic acid, cephalosporins, and combinations thereof. In addition, antimicrobial proteins and peptides such as bovine lactoferrin and lactoferricin B may be included as a bioactive agent in the coating.
[0080] Other bioactive agents which may be included in the coating of a mesh implant of the present disclosure include: local anesthetics; non-steroidal antifertility agents; parasympathomimetic agents; psychotherapeutic agents; tranquilizers; decongestants; sedative hypnotics; steroids; sulfonamides; sympathomimetic agents; vaccines; vitamins; antimalarials; anti-migraine agents; anti-parkinson agents such as L-dopa; anti-spasmodics; anticholinergic agents (e.g. oxybutynin); antitussives; bronchodilators; cardiovascular agents such as coronary vasodilators and nitroglycerin; alkaloids; analgesics; narcotics such as codeine, dihydrocodeinone, meperidine, morphine and the like; non-narcotics such as salicylates, aspirin, acetaminophen, d-propoxyphene and the like; opioid receptor antagonists, such as naltrexone and naloxone; anti-cancer agents; anti-convulsants; anti-emetics; antihistamines; anti-inflammatory agents such as honnonal agents, hydrocortisone, prednisolone, prednisone, non-hormonal agents, allopurinol, indomethacin, phenylbutazone and the like; prostaglandins and cytotoxic drugs; estrogens; antibacterials; antibiotics; anti-fungals; anti-virals; anticoagulants; anticonvulsants; antidepressants; antihistamines; and immunological agents.
[0081] Other examples of suitable bioactive agents which may be included in the coating of a mesh implant of the present disclosure include viruses and cells, peptides, polypeptides and proteins, analogs, muteins, and active fragments thereof, such as immunoglobulins, antibodies, beta glycans, cytokines (e.g. lymphokines, monokines, chemokines), blood clotting factors, hemopoietic factors, interleukins (IL-2, IL-3, IL-4, IL-6), interferons (β-IFN, (α-IFN and γ-IFN), erythropoietin, nucleases, tumor necrosis factor, colony stimulating factors (e.g., GCSF, GM-CSF, MCSF), insulin, anti-tumor agents and tumor suppressors, blood proteins, gonadotropins (e.g., FSH, LH, CG, etc.), hormones and hormone analogs (e.g., growth hormnone), vaccines (e.g., tumoral, bacterial and viral antigens); somatostatin; antigens; blood coagulation factors; growth factors (e.g., nerve growth factor, insulin-like growth factor); protein inhibitors, protein antagonists, and protein agonists; nucleic acids, such as antisense molecules, DNA and RNA; oligonucleotides; and ribozymes.
[0082] Any combination of bioactive agents may be utilized as part of a coating of the mesh implant of the present disclosure.
[0083] A coating may be applied to the mesh as a composition containing one or more bioactive agents, or bioactive agent(s) dispersed in a suitable biocompatible solvent.
[0084] Suitable solvents for particular bioactive agents are within the purview of those skilled in the art.
[0085] The rate of release of a bioactive agent from the coating on a mesh of the present disclosure can be controlled by any means within the purview of one skilled in the art. Some examples include, but are not limited to, the depth of the bioactive agent from the surface of the coating; the size of the bioactive agent; the hydrophilicty of the bioactive agent; and the strength of physical and physical-chemical interaction between the bioactive agent, the coating and/or the mesh material. By properly controlling some of these factors, a controlled release of a bioactive agent from the mesh of the present disclosure can be achieved.
[0086] In embodiments, filaments utilized to produce the strands of the mesh implant of the present disclosure may be made of bicomponent microfibers. Bicomponent microfibers typically include a core material and a surface material. In embodiments, the bicomponent microfibers may include a non-absorbable or long lasting absorbable core and a shorter lasting absorbable surface material. The surface material of the bicomponent microfiber may be absorbed by the body within a number of hours, such that only the core portion is left in the body for an extended period of time, typically for a long enough period of time to enable tissue ingrowth. Although a variety of materials may be used in forming these bicomponent microfibers, suitable materials include polypropylene for the core and polylactic acid or polyglycolic acid for the surface material. In another embodiment, the bicomponent microfibers may be made of a core material which may be rapidly absorbed by the body and a surface material which is not rapidly absorbed, but instead is absorbed for a longer period of time than the core.
[0087] In embodiments, the surface material of the bicomponent microfibers may provide the mesh implant with enhanced characteristics required for surgical handling. After insertion in the body, the surface material of the bicomponent microfiber may be absorbed by the body leaving behind the reduced mass of the core material as the strands of the mesh. For example, suitable bicomponent microfibers include a polypropylene non-absorbable portion as the core and a polylactic acid absorbable portion as the surface. The surface material is present during the surgical procedure when the mesh is being inserted and located in the patient, and provides the mesh with characteristics desirable for surgical handling. Following a period of insertion in the body, typically a few hours, the surface material is absorbed into the body leaving only the core material of the filaments in the body.
[0088] It may be desirable to provide a variety of implants having different sizes and dimensions so that a surgeon can select an implant of suitable size to treat a particular patient. This allows implants to be completely formed before delivery, ensuring that the smooth edge of the implant is properly formed under the control of the manufacturer. The surgeon would thus have a variety of differently sized and/or shaped implants to select the appropriate implant to use after assessment of the patient.
[0089] Methods of reducing fraying of the filaments to maintain a smooth edge of the mesh implant are within the purview of those skilled in the art and include, but are not limited to, heat treatment, laser treatment, combinations thereof, and the like. In some embodiments a heat treatment may be desirable, as such a treatment may promote adhesion of the strands forming the mesh, thereby facilitating removal of the mesh implant if required for any reason.
[0090] In another embodiment the mesh can be cut to any desired size. The cutting may be carried out by a surgeon or nurse under sterile conditions such that the surgeon need not have many differently sized implants on hand, but can simply cut a mesh to the desired size of the implant after assessment of the patient. In other words, the implant may be supplied in a large size and be capable of being cut to a smaller size, as desired.
[0091] Even where the cutting of the mesh causes an unfinished edge of the mesh to be produced, this unfinished mesh is not likely to cause the same problems as the rough and jagged edges of implants of the prior art, due to the coating, which protects the tissue from the mesh during the surgical procedure when damage to the tissue is most likely to occur.
[0092] Medical implants of the disclosure may include, but are not limited to, incontinence tapes and slings, and meshes, patches and/or implants for use in fascial repair, hernia repair, prolapse repair, and the like. Different shapes are suitable for repairing different defects. Thus, by providing a mesh implant which can be cut to a range of shapes, a wide range of defects, including those found in fascial tissue, can be treated.
[0093] In some embodiments, it may be desirable to secure the mesh in place once it has been suitably located in the patient. The mesh implant can be secured in any manner within the purview of those skilled in the art. Some examples include suturing the mesh to strong lateral tissue, gluing the mesh in place using a biocompatible glue, using a surgical fastener, or combinations thereof.
[0094] Any biocompatible glue within the purview of one skilled in the art may be used. In embodiments useful glues include fibrin glues, cyanoacrylate glues, combinations thereof, and the like. In other embodiments, the mesh implant of the present disclosure may be secured to tissue using a surgical fastener such as a surgical tack. Other surgical fasteners which may be used are within the purview of one skilled in the art, including staples, clips, helical fasteners, tissue anchors, suture anchors, bone anchors, hooks, combinations thereof, and the like.
[0095] Surgical fasteners useful with the mesh implant herein may be made from bioabsorbable materials, non-bioabsorbable materials, and combinations thereof. Examples of suitable absorbable materials which may be utilized to form a fastener include trimethylene carbonate, caprolactone, dioxanone, glycolic acid, lactic acid, glycolide, lactide, homopolymers thereof, copolymers thereof, and combinations thereof. Examples of non-absorbable materials which may be utilized to form a fastener include stainless steel, titanium, nickel, chrome alloys, and other biocompatible implantable metals. In embodiments, a shape memory alloy, such as nitinol, may be utilized as a fastener.
[0096] Surgical fasteners utilized with the mesh implant of the present disclosure may be made into any size or shape to enhance their use depending on the size, shape and type of tissue located at the repair site for attachment of the mesh implant. The surgical fasteners, e.g., tacks, may be used alone or in combination with other fastening methods described herein to secure the mesh to the repair site. For example, the mesh implant may be tacked and glued, sutured and tacked, or only tacked, into place.
[0097] The surgical fasteners may be attached to the mesh implant in various ways. In embodiments, the ends of the mesh may be directly attached to the fastener(s). In other embodiments, the mesh may be curled around the fastener(s) prior to implantation. In yet another embodiment, the fastener may be placed inside the outer edge of the mesh and implanted in a manner which pinches the mesh up against the fastener and into the site of the injury.
[0098] A mesh in accordance with the present disclosure possesses several desirable characteristics. In embodiments, where a non-absorbable material is utilized to form the strands of the mesh, the low surface density of a mesh of the present disclosure enhances the integration of the mesh with tissue, especially upon implantation in vivo. The collagen component of the coating minimizes the formation of adhesions and reduces the inflammation response to the mesh, while also improving the handling characteristics of the mesh for implantation by providing the mesh with stiffness. Moreover, the bioactive agent, in embodiments a fucan polysaccharide, may confer desirable properties to the mesh, for example the enhancement of cell proliferation and migration for enhanced and faster integration, antibacterial properties including the inhibition of both gram positive and gram negative bacteria, and the inhibition of inflammation, as evidenced by a decrease in complement activity. The bioactive agent, in embodiments a polysaccharide such as a fucoidan, may be released by the collagen coating immediately upon implantation, as well as for an extended period over several days.
[0099] A variety of different surgical approaches are contemplated herein for introducing the mesh implant of the present disclosure into a patient, including through an incision, laparoscopically, or through a natural approach such as, for example, vaginal approach, and the like.
[0100] The following Examples are being submitted to illustrate embodiments of the present disclosure. These Examples are intended to be illustrative only and are not intended to limit the scope of the present disclosure. Also, parts and percentages are by weight unless otherwise indicated.
EXAMPLES
Example 1
[0101] A mesh was prepared with the following parameters. A high tenacity PET multifilament yarn, about 49 dtex was utilized to form the mesh. A tricot warp knitting machine utilizing gauge E24 needles (i.e., 24 needles/inch) was utilized. The mesh included hexagonal pores, which were formed using 2 guide-bars, with the following bar movement:
[0102] Guide-bar BI: 1.0/0.1/1.0/2.3/3.2/2.3//
[0103] Guide-bar BII: 0.0/1.1/0.0/3.3/2.2/3.3//
[0000] The resulting mesh had a low surface density of from about 20 g/m 2 to about 35 g/m 2 , large pores of about 1.5 mm×1.5 mm, a ratio of longitudinal elastic properties/transversal elastic properties of from about 0.7:1 to about 1.3:1, and a breaking strength measured according to ISO 13934-1 in warp and weft direction of from about 80 Newtons to about 150 Newtons.
Example 2
[0104] The high tenacity PET mesh produced in Example 1 above was coated with a porcine collagen solution (about 0.8% mn/V), which was a Type I collagen extracted from pig dermis. Dried collagen fibers were used, obtained after precipitation of an acid collagen solution and adjunction of NaCl, followed by washings and dryings of the resulting precipitate with acetone aqueous solution with concentrations of from about 80% up to about 100%.
[0105] The mesh was coated by immersion in the solution, followed by wringing and drying the textile under a laminar air flow. At the end of the enduction process, the collagen coating on the textile was reticulated by an aqueous solution of glutaraldehyde at about 0.5% m/V (Fluka, Glutaraldehyde about 25%), at pH about 6.5 to about 7.5, over a period of about 2 hours. A reduction with sodium borohydrate was then performed. The reagents in excess were washed several times with water and rinsed.
Example 3
[0106] The molecular weight, polydispersity and structure of the fucan TH90 RED A2 0305 PUF30, was physicochemically characterized via Gel Permeation Chromatography (GPC, on a Column Zorbax G-F450 associated with a column TSK G2000 SW XL), Infra Red analysis (FTIR, on a Perkin Elmer 1600) and elemental analysis. This fucan had a low molecular weight (Mn about 12,000 to 17,000 g/mol), and a polydispersity index of about 1.78. The FTIR showed that the extraction process was reproducible and stable. Elemental analysis indicated that the sulfate content was about 25%. Furthermore, the final depyrogenation process utilized to obtain a pharmaceutical grade fucan did not alter the main molecule, as confirmed with GPC, FTIR and elemental analysis.
Example 4
[0107] In order to use the fucan with a mesh, the fucan of Example 3 was mixed with the collagen solution of Example 2 prior to application to the mesh of Example 1. Two concentrations of fucan were incorporated in the collagen solution: about 0.1% (m/V), sometimes referred to herein as “High Dose”, and about 0.01% (m/V), sometimes referred to herein as “Low Dose”. The coating of the yarns was performed as described above in Example 2.
[0108] In vitro assays were conducted in which about 1.5 mm diameter collagen-fucan disc shaped samples were prepared as models. The collagen-fucan films at a fucan concentration of about 0.1% contained about 250 μg of fucan, while the films at a fucan concentration of about 0.01% contained about 25 μg of fucan.
[0109] Fucan leaching from the collagen film was studied using High Pressure Liquid Chromatography (HPLC on a Dionex Carbo Pac 100).
[0110] Measurements were performed on the extracts of the collagen in combination with the collagen-fucan Low Dose after several hydration times of from about 20 minutes to about 96 hours in PBS buffer solution (Na 2 HPO 4 , 7H 2 O at about 0.726 g/L, NaCl at about 9 g/L, KH 2 PO 4 t about 0.21 g/L, [PBS Gibco, Invitrogen ref 20012-019] from Gibco, Life Sciences), at about 37° C. The results are set forth in FIG. 1 .
[0111] As can be seen in FIG. 1 , about 50% and about 70% of the incorporated fucan was released during the first 24 and 48 hours, respectively, of hydration in the PBS medium.
[0112] From these results, it can be seen that the fucan on the mesh may possess both local and diffuse effects during the first phase of implantation, which is the critical phase, in terms of immune and adverse reaction due to the surgery.
[0113] Moreover, incorporation of the fucan in a collagen film did not significantly alter its physico-chemical properties, in the case of fucan concentrations of less than about 0.1% (m/V).
Example 5
[0114] A mediated bacterial adhesion assay involving the fucan in collagen as described above in Example 4 was conducted. Cultures of the bacterial strain S. aureus (ATCC 6538; Gram+) were prepared by incubating a well-isolated representative colony selected from an agar plate in about 1 ml of broth at about 37° C. overnight.
[0115] Bacteria were harvested from this saturated bacterial suspension by centrifugation at about 3500 revolutions per minute (rpm) for about 15 minutes. After discarding the supernatant, the bacterial pellet, about 10 7 colony forming units (cfu)/ml, was suspended in about 1 ml of fresh broth and about 100 μL of tritiated thymidine (from Amersham, activity about 1 mCi/ml) was added. The resulting bacterial suspensions were incubated for about 3 hours at about 37° C. to obtain bacteria in the exponential growth phase. After the incubation period, the bacterial suspension was harvested twice at about 3500 rpm for about 15 minutes to remove the excess unbound radioactive thymidine.
[0116] A solution of PBS with Ca ++ and Mg ++ was then added to the bacterial pellet to obtain suitable bacterial dilutions (about 10 6 -10 7 cfu/ml) and the bacterial suspension was homogenized using a vortex-mixer.
[0117] Collagen from Example 2 and collagen-fucan Low Dose samples from Example 4 were utilized to prepare films. The films were first coated with plasma constituents and then incubated with about 500 μl of PBS for about 50 hours under stirring.
[0118] About 500 μl of the washed-log phase radiolabeled bacterial suspension (about 10 6 -10 7 cfu/ml) described above was then added to the films. The bacterial suspension on the film was incubated for about 3 hours at about 37° C. After about 5 washings with PBS buffer, each sample was transferred to counting vials; about 10 ml of scintillation fluid (Optiphase Hisahe, EG and G) were added; the amount of bacteria which adhered onto the implants was measured using an automatic β-liquid scintillation analyser model (Tri CARB 2100 TR (Packard IND 1401)).
[0119] In order to check that the investigated bacteriophobic activity was due to the fucan, additional collagen films (with and without fucan) were first coated with plasma constituents and incubated with a mixture of about 500 μl of the above washed-log phase radiolabeled bacterial suspension (about 10 6 -10 7 cfu/ml) in combination with about 500 μl of a solution of collagen-fucan Low Dose implant extracts obtained after about 50 hours of incubation in PBS buffer at about 37° C. The resulting mixture was incubated for about 3 hours at about 37° C. After about 5 washings with PBS buffer, each sample was transferred to counting vials; about 10 ml of scintillation fluid (Optiphase Hisahe, EG and G) were added; the amount of bacteria which adhered onto the implants was measured using an automatic β-liquid scintillation analyser model Tri CARB 2100 TR (Packard IND 1401).
[0120] The results are set forth in FIG. 2 , which shows the bacterial adhesion on collagen and collagen-fucan films. In FIG. 2 , the two bar graphs for (a) demonstrate the adhesion of S. aureus on collagen (C) and collagen-fucan Low Dose (CF) films; the three bar graphs for (b) demonstrate the adhesion of S. aureus on a control of porous polypropylene (T′), collagen films (C′) and collagen-fucan Low Dose films (CF′) in the presence of collagen-fucan Low Dose extracts.
[0121] As can be seen in FIG. 2 , the bacterial adhesion was more prevalent on the control and was statistically different than bacterial adhesion obtained on collagen films. Moreover, as can be seen in FIG. 2( a ), films possessing fucan incorporated into collagen demonstrated a decrease in bacterial adhesion. The inhibition rate reached an average value of about 37% (after a period of incubation of about 50 hours in buffer).
[0122] In the case of the extract diffusion, an inhibition of bacterial adhesion on the three types of implants was observed (see FIG. 2( b )). Bacterial adhesion inhibition reached an average value of about 40%, which was nearly equal the rate obtained for the first experiment (about 37%). The bacterial inhibition obtained on T′ (textile alone) was less (about 31% inhibition) as compared to the one observed on C′ (collagen film) and CF′ (Low Dose film).
[0123] The above results demonstrate that the fucan was released from the collagen-fucan Low Dose film during the first 50 hours, and was responsible for the inhibition of adhesion.
Example 6
[0124] In vivo experiments were conducted to check the antibacterial properties of a collagen-fucan implant in a rat contaminated model. About 2.5×3.5 cm shaped composite implants were constructed with the two-dimensional non biodegradable textile of Example 1. Multiple implants were prepared; some possessed a collagen film coating as described in Example 2, while others possessed a collagen-fucan film coating as described in Example 4. The implants were implanted in rat peritoneal cavities at the site of a preformed 1.5×2.5 cm parietal defect. The implants were sutured with 6 points and the surgery was ended with suture strand. High virulence E. coli bacteria were inoculated (10 9 bacteria in 2 mL of phosphate buffer Na 2 HPO 4 , 7H 2 O; 0.1M; pH 7.2 [PBS, Invitrogen 20012-068]) by means of a percutaneous injection in the region of the implant/defect.
[0125] After time periods of about 2 days and about 30 days, the rats were sacrificed and the meshes explanted. The proliferated bacteria were detached from the explants and cultured on agar gelose before being counted. Immunohistology was also performed in order to identify the bacteria.
[0126] Fucan, at high dose, inhibited bacterial proliferation after 30 days (2 logs of inhibition). No significant effect was observed after 2 days of incubation. The results are summarized in Table 1 below.
[0000]
TABLE 1
# of Rats
Mesh reference
Timing
E. Coli
7
Textile*
J2
5.43E+08
7
Textile High Dose**
J2
2.73E+08
7
Textile Low Dose***
J2
5.17E+08
7
Textile*
J30
9.43E+10
7
Textile High Dose**
J30
1.74E+09
5
Textile Low Dose***
J30
8.28E+10
J2 = rats sacrificed after 2 days
J30 = rats sacrificed after 30 days
*Textile - mesh with collagen coating
**Textile High Dose = mesh with collagen and High Dose fucan coating
***Textile Low Dose = mesh with collagen and collagen-fucan Low Dose coating
Example 7
[0127] In-vitro cell culture characterization. The effects of fucans, incorporated in the collagen films as described above in Example 4, were analyzed at several concentrations on several different cells and their effects on cell proliferation were studied. The cells tested included fibroblasts, mesothelial cells, mesenchymal stem cells, urothelial cells, endothelial cells and smooth muscle cells (SMCs).
[0128] Normal human dermal fibroblasts (NHDF, Cambrex CC2511) were cultured in Dulbecco's Modified Eagle's Medium (DMEM, Cambrex CC3132) supplemented with about 10% fetal calf serum (FCS, Fischer 10270106), about 1% Fungizone (Fischer 15290026) and about 1% Penicillin/Streptomycin (Fischer 15140122). Cells were maintained in a controlled atmosphere (about 37° C., about 95% relative humidity and about 5% CO 2 ). All the experiments were carried out using cells with passage numbers of less than about 25 (passage=treatment with trypsin-ethylenediamine tetraacetic acid (EDTA)).
[0129] NHDF were grown onto the collagen-fucan film of Example 4, which included a collagen based gel associated with different concentrations of fucan, optionally associated with a 2D textile of Example 1. Cell growth was studied for about 7 days. Each experiment was repeated 3 times. The results of this experiment are set forth in FIG. 3 , which shows the fibroblast growth on collagen-fucan TH90 RED A2 0305 PUF 30. As depicted in FIG. 3 , G0, G0.01, G0.05 were collagen film without textile containing respectively about 0%, about 0.01%, and about 0.05% (m/V) of fucan; T0, T0.01, T0.05 were composite collagen films/2D textiles containing respectively about 0%, about 0.01%, and about 0.05% (m/V) of fucan.
[0130] The fibroblasts demonstrated an affinity for the collagen-fucan surfaces (see FIG. 3 ). The optimal concentration was evaluated at about 0.01% (m/V) of fucan in the collagen solution, i.e., a non degrading concentration for the physical integrity of the film.
[0131] The presence of the textile reduced the cell adhesion and proliferation rate. This may be due to the surface properties (e.g., planarity) induced by the presence of the textile, as well as differences in the degradation rate of the film and its impact on the cell adhesion and proliferation.
Example 8
[0132] Cell migration is a major process in tissue repair and wound healing. Cell migration was studied using a Boyden chamber assay through inserts with 8 μm pores. A depiction of a Boyden chamber is set forth in FIG. 4 .
[0133] Cells were suspended in culture medium and added to the upper chamber of the assay wells. Migration assays were performed in the presence of fucan matrices (T0, T0.01, G0, G0.01 as described above in Example 7), polypropylene (PP) or polyethylene terephthalate (PET) in the lower chamber. The chemotactic response to fucan was determined for fibroblasts. Positive controls were performed (migration in presence of about 20% fetal calf serum (FCS, Fischer 10270106)).
[0134] The results are presented in FIG. 5 , which demonstrates the chemotactic response of fucans on fibroblasts. As can be seen in FIG. 5 , the migration of fibroblasts was stimulated in presence of fucans (comparison between G0.01 and G0 and between T0.01 and T0). The same effect was observed when fucan was released from the matrix including polypropylene and collagen (T0.01) or from the sole collagen matrix (G0.01), and reached about 60%.
[0135] No statistical difference was observed when the fibroblasts or mesothelial cells migrated in the presence of PP or PET matrices in the medium.
Example 9
[0136] The anti-complement activity of fucans was tested via a CH50 test, a standard hemolytic assay in total human serum.
[0137] Complement activation in human serum was induced by the introduction of sheep erythrocytes coated with rabbit antibodies and then recognized as foreign elements. This led to the activation of the classical pathway of the complement system, and hence to the lysis of erythrocytes.
[0138] The amount of released hemoglobin was then determined by an optical density (OD) measurement at about 414 nm. The human serum dilution was adjusted for a known amount of erythrocytes, in order to lyse about 50% of the red blood cells (CH50).
[0139] In order to check the impact of the fucan on the complement activation in solution, the fucan was added with the sheep erythrocytes. A decrease in cell lysis, as evidenced by a decrease of the OD at about 414 nm, demonstrated that the fucan inhibited the complement activation.
[0140] Heparin (heparin H 108 173 UI/mg, Choay-Sanofi) and fucan P240 RED synthesized in the Laboratoire de Recherche sur les Macromolecules (LRM, CNRS UMR 7540, France) were also tested instead of fucan.
[0141] The results are set forth in FIG. 6 , which depicts the anti-complement activity of heparin H108, P240 RED and fucan TH90RED A2 0305 PUF 30 in solution.
[0142] As can be seen in FIG. 6 , the fucan TH90RED A2 0305 PUF30 like its precursor P240 RED, presented dose-dependent anti-complement activity; both had an IC50 (median inhibition concentration) of about 4 μg/mL, evidencing a strong anti-complement activity as compared with the reference heparin H108 (IC50 about 30 μg/mL as measured in this test).
Example 10
[0143] In order to check the in-vivo integration of composite implants made of a 3D non biodegradable textile (PET) associated with a collagen film and collagen-fucan film, an intraperitoneal implantation in rat peritoneal cavity was performed. 2 sites in 25 rats were implanted with 3 kinds of implants: collagen/textile implant, as a control; collagen-fucan Low Dose/textile implant; and collagen-fucan High Dose/textile implant.
[0144] The mesh integration and associated adherences were observed after about 3 days, about 5 days, about 7 days, and about 6 weeks, by both macroscopic and immunohistological observations.
[0145] The results of the histological analysis of explanted composite implants is set forth in FIG. 7 which depicts images of tissue obtained by histological observation. As can be seen in FIG. 7 , after 3 days of implantation better integration of the mesh associated with the collagen-fucan Low Dose was observed compared with the composite control. The mesh containing the collagen-fucan Low Dose (0.01% (m/V)) showed multiple layers of fibroblastic cells after about 3 days of implantation. Statistical differences were observed for tissue integration between the collagen-fucan Low Dose and control.
[0146] The following days (see day 5 data and day 7 data on FIG. 7 ) presented a faster integration of the mesh associated with the collagen-fucan Low Dose compared to the composite control, with comparable inflammatory reactions. Integration of all the meshes was observed about 7 days after implantation. The moderate inflammatory reactions observed did not prevent the final integration of the mesh.
[0147] No data were available for the collagen-fucan Low Dose implant at 6 weeks, because the rat died during the experiment. This death was not due to the experiment.
[0148] While the above description contains many specifics, these specifics should not be construed as limitations on the scope of the disclosure herein but merely as exemplifications of particularly useful embodiments thereof. Those skilled in the art will envision many other possibilities within the scope and spirit of the disclosure as defined by the claims appended hereto.
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A mesh implant is disclosed which may be utilized for treating urinary incontinence, hernias, uterovaginal prolapses and other related injuries.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to strut assemblies and, more particularly, to strut assemblies which support external elements to vehicles, for example, mirrors for viewing remote areas around the vehicles.
2. Related Art
It is known to provide vehicles with rear view and side view mirrors to enable a driver to see various areas around the vehicle. In some cases, the vehicle is used to transport small children and, therefore, requires special mirrors for viewing atypical areas around the vehicle, for example, the lower front area of the vehicle. By providing a downwardly directed and forwardly disposed mirror, it is possible to insure that no children are present in front of the vehicle before the driver moves the vehicle forward.
Unfortunately, not all manufacturers of vehicles offer special mirrors as stock or optional equipment. Therefore, a retrofit action is required to install such special mirrors onto stock vehicles used to, for example, transport children.
Moreover, when forwardly disposed and downwardly directed special mirrors are required as described above, vehicle vibrations becomes a critical issue particularly when a retrofit action is required. This is so because on some vehicles the front fenders to which these mirrors are mounted are ill-equipped to receive the struts which support the special mirrors and, therefore, the mirrors tend to vibrate at unacceptable levels. Specifically, the struts which are used to support the mirror must couple to the stock vehicle at one or more locations. Unfortunately, it is generally required to connect at least one strut to a portion of the sheet metal body at the front fenders of the vehicle which does not have adequate support to the vehicle frame to prevent vibration of the mirror.
Accordingly there is a need in the art for a strut assembly which is capable of supporting a mirror on a vehicle in a retrofit application and which reduces (dampens) the vibrations in the mirror to acceptable levels.
SUMMARY OF THE INVENTION
In order to overcome the problems in the art described above, as well as other problems, the strut assembly of the preferred embodiment of the present invention includes a plurality of strut portions, including a first strut portion which is operatively coupled to an external element (for example, a mirror) and a second strut portion which is operatively coupled to a portion of the vehicle body, and a support bracket operatively engaging, at a first end thereof, both the portion of the vehicle body and the second strut portion and, at a second end thereof, the frame of the vehicle such that vibrations of the external element are reduced.
It is noted that the external element may be a camera, a spot light, a fog light, a loud speaker or the like without departing from the scope of the invention.
Other features and advantages of the present invention will become apparent from the following description of the invention which refers to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
For the purpose of illustrating the invention, there is shown in the drawings a form which is presently preferred, it being understood, however, that the invention is not limited to the precise arrangement and instrumentality shown.
FIG. 1 is a perspective view of the strut assembly of the preferred embodiment of the present invention coupled to the body of a vehicle;
FIG. 2 is a side schematic view of the strut assembly of FIG. 1 from the direction z;
FIG. 3 is a top view of the support bracket of the preferred embodiment of the present invention; and
FIG. 4 is a perspective view of the support bracket of FIG. 3 in use on the vehicle.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the drawings wherein like numerals indicate like elements, there is shown in FIG. 1 the front portion of a vehicle 10 on which a strut assembly 100 is mounted. The strut assembly 100 includes struts 120 which connect to the vehicle at points A, B and C (point B is not visible in FIG. 1). The strut assembly is also connected to a mirror 110 and supports same in a position which is desired by a driver.
It is preferred that the mirror 110 be generally round and convex such that a wide viewing area is obtained. It is also preferred that the struts 120 be arranged such that the mirror 110 be oriented generally downward and that the mirror 110 be disposed generally forward of the vehicle 10. As such, a driver may readily see the lower front area of the vehicle and determine whether children are present before moving forward. It is understood that different types of mirrors 110 may be employed and that the mirror 110 may be disposed at other locations of the vehicle and still be within the scope of the present invention.
With reference to FIGS. 1 and 2, the connection of the strut assembly 100 to the vehicle 10 is described. FIG. 2 is a side schematic view of the strut assembly 100 from direction "z" in FIG. 1. As shown, the struts 120 include strut portions 121-126 where strut portions 121, 125 and 126 are connected to the vehicle 10 at points A, B and C, respectively.
It is appreciated that strut elements 121, 122, 123, 124 and 125 all lie in generally the same plane. Accordingly, strut element 124 reduces the relative movement between strut elements 121 and 122 in the direction indicated by the letter "y" in FIG. 2. Thus, vibrations in the mirror 110 are reduced when the strut 121 is mounted to the vehicle 10 at point A.
It should be appreciated that strut element 125 couples strut elements 121 and 122 to the vehicle 10 at point B, where point B is on or near the lip of the left front quarter panel 12 adjacent the windshield 14 (FIG. 1). Accordingly, strut element 125 reduces the relative movement between the vehicle 10 and strut elements 121 and 122 in the direction indicated by the letter "x" in FIG. 2. Thus, vibrations in the mirror 110 are further reduced.
The strut assembly 100 is further coupled to the vehicle 10 via strut portion 126 which is mounted to the left front quarter panel 12 at point C. It is noted that strut portion 126 is not in the same general plane as the other strut elements and, therefore, reduces relative movement of the strut assembly 100 in a direction indicated by the letter "z" in FIG. 1, which direction is generally perpendicular to directions x and y.
It is noted that the majority of stock vehicles do not come equipped with support structures under the sheet metal body of the left front quarter panel 12 (FIG. 1) at point C. As a result, coupling the strut portion 126 to the vehicle at point C has only marginally acceptable results in reducing mirror vibrations. Stock vehicles 10 likewise do not come equipped with support structures under the sheet metal body of the right front quarter panel 16 (not shown) at a point D corresponding to point C shown in FIG. 1.
Reference is now made to FIG. 4 which is a perspective view of the right front quarter panel (fender) 16 of the vehicle 10 as seen from inside the motor compartment 20. A strut assembly 100 having strut portions 122, 121 and 126 is mounted to the right front quarter panel 16 in substantially the same way as described above with respect to the left quarter panel 12.
Strut portion 126 is mounted to the vehicle 10 at point D. A front portion of the vehicle frame 18 is shown to which the right front fender is mounted. In accordance with the preferred embodiment of the present invention, a support bracket 200 is included which operatively couples and bridges the portion D of the front quarter panel 16 to the vehicle frame 18. Thus, the support bracket 200 sufficiently stiffens the sheet metal body of the vehicle 10 at point D to adequately reduce vibrations in the mirror 110. More specifically, the fender 16 has an exterior surface 16' and an interior surface 16". The support bracket 200 has a curved portion 201 which reaches to and engages the interior surface of the fender 16, at a point juxtaposed to the exterior point D on the fender 16. The other end 203 of the support bracket 200 is rigidly attached to the vehicle frame 18.
FIG. 3 shows a top view of the support bracket 200 in more detail. The support bracket 200 is formed of a substantially rigid material, for example, steel, aluminum, plastic or the like. The support bracket 200 is preferably substantially rectangularly shaped and includes a compound bend 206 which is formed by bending one end of the bracket 200 upward (in a direction perpendicular to the arrow "y") and simultaneously downward (in the direction of the arrow "y"). The compound bend 206 enables the support bracket 200 to operatively engage both the sheet metal body of the vehicle 10 at point D and the vehicle frame 18.
The support bracket is further provided with mounting holes 202 which permit the bracket to be mounted to the vehicle frame 18 via bolts, rivets or the like. The bracket 200 is also provided with holes 204 for permitting operative coupling to both the body of the vehicle 10 and the strut portion 126 of the strut assembly 100. It is preferred that the support bracket 200 have a length of about 5 inches, a width of about 1 inch and a thickness of about 1/8 inch.
It can be appreciated that the strut support 100 of the preferred embodiment of the present invention provides a means for the retrofitable coupling of a mirror to the body of a vehicle which reduces vibrations in the mirror and, therefore, provides for a superior view of, for example, the lower front region of a vehicle for carrying children such that safe operation of the vehicle may be obtained.
Although the present invention has been described in relation to particular embodiments thereof, many other variations and modifications and other uses will become apparent to those skilled in the art. It is preferred, therefore, that the present invention be limited not by the specific disclosure herein, but only by the appended claims.
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A strut assembly for supporting an external element (for example, a mirror) to the body of a vehicle includes a plurality of strut portions, a first strut portion of which is operatively coupled to the external element and a second strut portion of which is operatively coupled to a portion of the vehicle body, and a support bracket operatively engaging, at a first end thereof, both the portion of the vehicle body and the second strut portion and, at a second end thereof, the frame of the vehicle such that vibrations of the external element are reduced.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims priority from U.S. Provisional Application No. 61/897,160, filed Oct. 29, 2013, the entire contents of which application are hereby incorporated by reference.
BACKGROUND
A device characterization measurement system is one that measures certain parameters of a Device Under Test (DUT) by sampling and measuring signals applied to and coming from the DUT.
Such a system may use various instruments, such as signal generators, spectrum analyzers, power meters, network analyzers in order to characterize the DUT.
A “tuner system”, “automated tuner system”, “impedance tuner system” or “load pull system” refers to a device characterization measurement system which uses some form of impedance tuner(s) to control the impedance(s) seen by the DUT, and measure certain parameters as a function of varying impedance.
Impedance tuners may be mechanical and utilize mismatch probes, or solid-state and utilize switches or diodes. As used herein, “probes” will refer to mismatch probes.
The specific position of mismatch probe, or the state of the switch or diode, will dictate the impedance presented to the DUT.
Impedance tuners may be “manual tuners” where the impedance tuner is manually controlled by the user without influence of a computer, or “automated tuners” which are controlled by a computer or microprocessor.
Automated impedance tuners use some form of software, either embedded within the tuner or standalone on an external computer, to control the probe position or impedance state.
External software, i.e. software installed not within the tuner's memory but on a separate and distinct computer system, is used to characterize a tuner which associates scattering parameters (s-parameters) with tuner positions or states.
External software is used to perform calibration and measurements, which includes communicating with various instruments in the tuner system, reading data from said instruments and de-embedding results to the DUT reference plane.
BRIEF DESCRIPTION OF THE DRAWINGS
Features and advantages of the disclosure will readily be appreciated by persons skilled in the art from the following detailed description when read in conjunction with the drawing wherein:
FIG. 1 is a simplified schematic diagram of a tuner system with an integrated controller system. As used herein, “controller” refers to a tuner controller.
FIG. 1A diagrammatically illustrates an exemplary embodiment of an electromechanical impedance tuner system.
FIG. 1B is a functional block diagram of exemplary embodiment of a tuner controller for the system of FIG. 1A, 1C or 1D .
FIG. 1C diagrammatically illustrates an exemplary embodiment of an electromechanical impedance tuner system with external controller system.
FIG. 1D illustrates an exemplary embodiment of a tuner system with a flat panel display or a tablet computer mounted to the tuner housing.
FIG. 2A diagrammatically illustrates an impedance tuner connected to a vector network analyzer (VNA).
FIG. 2B illustrates an exemplary tuner characterization file.
FIG. 3 illustrates a block diagram of an exemplary embodiment of a tuner system connected on a THRU, i.e. a direct connection or a transmission line connection of some known length and scattering parameters, for system calibration
FIG. 4 illustrates a block diagram of an exemplary embodiment of a tuner system connected to a DUT for measurement.
FIG. 5 shows a screen shot on an exemplary TUNER APP characterization configuration page.
FIG. 6 shows a screen shot on an exemplary TUNER APP characterization measurement page.
FIG. 7 shows a screen shot on an exemplary TUNER APP system calibration configuration page.
FIG. 8 shows a screen shot on an exemplary TUNER APP system calibration measurement page.
DETAILED DESCRIPTION
In the following detailed description and in the several figures of the drawing, like elements are identified with like reference numerals. The figures are not to scale, and relative feature sizes may be exaggerated for illustrative purposes.
In a general sense, an impedance tuner system includes a signal transmission line and an impedance-varying system coupled to the transmission line. FIG. 1 is a simplified block diagram of an exemplary tuner system 10 , including the RF signal transmission line 12 with I/O ports 14 and 16 . An impedance varying system 20 is coupled to the signal transmission line to selectively affect the impedance presented by the signal transmission line, as is well known in the art. In one exemplary embodiment, the impedance tuner can be an electromechanical tuner with the typical features of a transmission line, one or more probes mounted on one or more probe carriages, and motors for moving the probes and carriages in the horizontal and vertical axes relative to a transmission line axis. The tuner 10 can have sensors such as position detection sensors to limit the horizontal and vertical movements of the probes, and obtain initialization information regarding the carriages. In other embodiments, the impedance tuner can be a solid state tuner, with impedance variation achieved by applying control signals to solid state elements.
A tuner controller 30 is provided to convert user commands such as desired gamma settings for a selected frequency into electronic control signals for controlling the impedance-varying system. The tuner controller 30 can be mounted on board the impedance tuner, i.e. integrated with the tuner and inside of, or supported by, the tuner housing, or it can be external to the tuner housing. In the case of an electromechanical tuner, the control signals can include motor drive commands for positioning the probe or probes at a desired position or positions to affect the impedance. The tuner controller 30 in this embodiment is connected to communication port(s) 40 , and includes communication server and memory functions. The tuner 10 typically has other ports 42 , such as a power input port, a USB port and the like. The communication port(s) may be capable of TCP/IP support, e.g. an RJ-45 Ethernet port.
An impedance tuner is often “characterized” on a vector network analyzer (VNA) before it can be intelligently used as part of an automated tuner system ( FIG. 2A ). Here, an impedance tuner 10 is connected to a VNA 150 for the characterization process.
Tuner characterization involves recording the scattering parameters (s-parameters) of the tuner as a function of probe position or tuner state. The results are often stored in tabular format or in a database. FIG. 2B shows a screen shot of an exemplary tuner characterization table.
S-parameters are typically used in determining the correct tuner position or state in order to present the user-specified impedance to the DUT. The S-parameters of the tuner can be cascaded with the s-parameters of additional components within the system in order to de-embed or shift reference planes. This is important when the DUT is not directly connected to the impedance tuner, or when the measurement instrument is not directly connected to the impedance tuner, and losses and phase shifts must be taken into account.
External software is used to perform tuner characterization. This software resides on an external computer, and contains software drivers to communicate with VNAs. Software drivers contain specific commands that may be unique to each instrument. The external software also contains a software driver for the tuner system, and the characterization algorithm which drives the tuner, communicates with the VNA via drivers, and records characterization data in a table or database. Exemplary characterization procedures and algorithms are described in the operating manual for the Maury Microwave impedance tuner, MT993-2, Rev M, Chapter 5, September 2008, by way of example.
Once an impedance tuner is characterized, it is assembled into a measurement system along with measurement system devices. As used herein, a “system device” is any component of the measurement system, and may include instruments, such as a signal generator and power meter. In this example, the signal generator is used to generate and inject the test signal into the DUT, the impedance tuner is used to vary the impedance presented to the DUT, and the power meter is used to record the output power of the DUT.
The “system-calibration” or “power-calibration” of the tuner system can involve connecting the system as shown in FIG. 3 on a THRU, without the DUT connected. The relationship between the signal generator power, power available to the input of DUT, and power at the output of the DUT is calculated. FIG. 8 shows an exemplary calibration data set resulting from a system calibration.
Other calibration techniques include using power meters for forward and reverse reflected power to determine power delivered to the DUT or a vector-receiver measuring incident and reflect waves in order to determine power delivered to the DUT. The measurement system can include more than one impedance tuner, as shown in FIGS. 3 and 4 , in which a load tuner 50 and an input tuner 50 ′ are arranged on input and load sides of the DUT, with the load tuner 50 controlling operation of the measurement system and the system devices, including the input tuner 50 ′. Additional tuners can also be used in some measurement system applications.
External software is typically used to perform system calibration. This software resides on an external computer, and contains software drivers to communicate with external instruments or system devices connected in a measurement system. Software drivers contain specific commands that may be unique to each instrument. The external software also contains the system calibration algorithm which drives the tuner, communicates with the various instruments via drivers, and records calibration data in a table or database. Exemplary calibration procedures and algorithms are described in the operating manual for the Maury Microwave impedance tuner, MT993-2, Rev M, Chapter 5, September 2008, by way of example.
Measuring the DUT's parameters involves replacing the THRU from the system calibration with the DUT, as shown in FIG. 4 .
External software is typically used to measure the DUT's parameters. This software resides on an external computer, and contains software drivers to communicate with external instruments. Software drivers contain specific commands that may be unique to each instrument. The external software also contains the DUT measurement algorithm which drives the tuner, communicates with the various instruments via drivers, and records measured parameter data in a table or database. US Publication 20100030504 describes an exemplary DUT parameter measurement algorithm, a noise measurement algorithm.
In accordance with exemplary embodiments of the invention, for the first time, one or more instrument drivers, characterization, calibration and measurement algorithms are embedded into an impedance tuner's controller, so that, in addition to converting user commands into electronic signals for controlling the impedance-varying system, users have the capability to access and execute these functions, e.g., via a GUI (graphical user interface) applet or user interface devices, without use of an external computer to store the system software drivers and execute the algorithms. “Embedding” the drivers and algorithms means that they are stored in memory or firmware of the impedance tuner controller, in contrast to being stored on an external computer device and not locally on the impedance tuner controller. An external communication device 200 ( FIGS. 3 and 4 ) may be used to allow a user to run the applet on the external device to provide user command instructions to the tuner controller. The external communication device may be a cell phone, laptop or tablet computer, or a desktop computer, for example. In this case, the external communication device does not store the system device drivers, and the characterization, calibration and measurement algorithms, which are embedded on the tuner controller. Rather, the external communication device is used to send high level user command instructions to the tuner controller, e.g. to initiate the particular function or functions to be performed.
The external communication device 200 may be connected to the tuner controller by a Wi-Fi, Bluetooth or cellular network, an Internet connection or by a cable connection. Alternatively, a user interface device such as a mouse and/or keyboard may be used, in conjunction with a display mounted to the tuner device or controller housing, to access and control the tuner functions, such as characterization, calibration and measurement functions. The communication ports of the tuner controller include ports configured to communicate command signals to controlled devices in a measurement system, in a system in which the tuner 10 is configured to control the measurement system, e.g. through characterization, calibration, and measurement modes or functions. The communication port may include an antenna for wireless communication using networks such as Wi-Fi, Bluetooth or cellular networks.
FIG. 1D illustrates an exemplary embodiment of a tuner 50 ″ in which the tuner controller 80 ″ includes a tablet computer, which can be mounted to the housing structure 52 ″ of the tuner. A computer port such as a USB port of the tablet computer is connected to the tuner by a USB cable 94 ′. Electrical power can be supplied to the table computer by a power cable 96 . The tablet computer can be one of the tablets configured to run the Windows operating system, for example; in other embodiments, tablets running other operating systems can be configured for use. The tablet computer 80 ″ includes in this example a touch screen 82 ″ for user manipulation to input commands and control operation of the tuner system, to convert user commands, such as desired gamma settings for a selected frequency, into electronic control signals for controlling the impedance-varying system, as well as to control the measurement system devices to execute the characterization, calibration and measurement functions. The instrument drivers, and the characterization, calibration and measurement algorithms may be stored on the tablet memory storage drive, for example. The tablet computer can be mounted to the cover by a tablet holder structure permitting removal of the tablet from the housing structure. Alternatively, the housing structure may include an open window, and the tablet computer mounted to the inside surface of the housing structure, with the screen 82 ″ accessible and visible through the window.
In an exemplary embodiment, the self-characterizing, self-calibrating and self-measuring impedance tuner or tuner controller is web-enabled, including features described in application Ser. No. 13/081,462, filed Apr. 6, 2011, now issued as U.S. Pat. No. 8,823,392, the entire contents of which are incorporated herein by this reference, and sometimes referred to herein as the '462 application. While an exemplary embodiment is configured to perform all three functions, i.e. the self-characterizing, self-calibrating and self-measuring functions, there may be applications in which an embodiment of an impedance tuner is configured to implement only one of these functions, or for only two of the functions. For example, an impedance tuner controller may be configured to implement only self-characterizing and self-calibrating functions, and not the self-measuring function.
An exemplary embodiment of a self-characterizing, self-calibrating and self-measuring impedance tuner may work in conjunction with a web-enabled tuner controller which can be configured and controlled from a standard web browser, such as Microsoft Explorer, Mozilla Firefox, Google Chrome, and Apple Safari, via a TCP/IP based network. Alternatively, the impedance tuner can be controlled by a tuner controller which is configured and controlled by user input devices such as a mouse, keyboard or touch screen. The self-characterizing, self-calibrating and self-measuring tuner or tuner controller may include one or more of the following features:
1) A built-in or integrated, tuner controller 80 ( FIG. 1A ). This will avoid the need for the customer to connect a stand-alone controller to the tuner, through a jack or USB connector, to provide control signals to the carriage motors (for a mechanical tuner) or to switches for a solid state tuner, and to process the sensor signals. The built-in controller may be microprocessor-based, or fabricated as an application specific integrated circuit (ASIC) or field programmable gate array (FPGA). The built-in controller may be web-enabled. 2) A tuner controller 80 ′ ( FIG. 1C ) external to the tuner, and configured for connection to the tuner by, e.g., a USB or other communication link. The external tuner controller may be web-enabled. 3). A tablet computer with a touch sensitive screen, as part of the tuner controller 80 ″ ( FIG. 1D ) mounted or supported by the tuner housing 4) A server function integrated on the tuner, or with the tuner controller. 5) The tuner controller is configured so that the tuner operator can use a computer or terminal, a user interface device 200 , such as a tablet, laptop, PC or smart phone, with a client application such as a web browser to navigate to the IP address of the tuner, which can be configured to download a web page or pages to the terminal. The web pages provide a visual or graphical interface for the user to set up and control the operation of the tuner. The operational instructions to the tuner are processed by the tuner controller, for example, to determine the motor commands needed to obtain the desired tuner operation in the case of an electromechanical tuner, or determine solid state control conditions, e.g. in the case PIN diodes, the diode bias conditions, for a solid state electronic tuner. The algorithms ( 84 C, 84 D, 84 E, FIG. 1B ) for the tuner characterization, calibration and measurement modes, as well as the measurement system device drivers, all reside on the tuner controller, i.e. are stored on memory or firmware of the tuner controller. 6) The web page may include an embedded JAVA applet, providing the capability of graphical tuner control, and opening a Telnet communication channel to the tuner and allowing text-based command signals to be sent to the tuner from the PC. In an exemplary embodiment, the JAVA applet runs on the PC, and provides on the PC: (i) a visual setup web page for the tuner, (ii) an instrument driver manager, (iii) a configuration page for tuner characterization, (iv) a measurement page for tuner characterization, (v) a configuration page for system calibration, (vi) a measurement page for system calibration, (vii) a measurement page for DUT parameter measurement, 7) The tuner web page may be configured to allow textual web tuning by typing a tuning target or other tuner data point or command in a text box (e.g. in an HTML page) without a JAVA applet, and the controller retrieves data entered by user from the HTML page and acts on this information to control the tuner. 8) An on-board file system with the controller acting as an FTP server. FTP client software, such as File Explorer, on a PC can be used to access on-board file system, allowing files to be transferred between the PC and tuner. The on-board file system in an exemplary embodiment is configured to store calibration and s-parameter data files, as well as configuration and setup data. The on-board file system may also store measurement data. 9) A set of connectors for providing control signals to other devices in the measurement system, such as a signal generator and power meter. Alternatively, the tuner controller may be connected on a network with the other devices, on a signal buss, for example. 10) Tuner characterization, calibration and measurement algorithms ( 84 C, 84 D, 84 E, FIG. 1B ) and system device drivers ( 84 F) are resident on the tuner controller memory or firmware.
As noted above, the web-enabled tuner controller 80 ′ ( FIG. 1C ) may be external to the tuner, and connected to the tuner by a communication link. A user at a PC or other terminal can still control the tuner through commands transmitted to the tuner controller, which in turn processes the commands and generates the appropriate tuner control or drive commands as well as the measurement system device commands to perform the characterization, calibration and/or measurement functions. This embodiment may be useful to control existing, tuner systems already deployed in the field, for example, without requiring expensive retrofits.
FIG. 1A shows an exemplary embodiment of an electromechanical impedance tuner system 50 . In this example, the impedance tuner includes a housing structure generally indicated as 52 , and an RF signal transmission line 54 , in this example a slab line, with input/output (I/O) ports 56 , 58 for connection to a DUT, signal source, termination, network analyzer or other equipment in a measurement or calibration setup. The impedance varying system 60 in this embodiment includes one or multiple (two are shown in this example) carriages 62 , 64 , each mounting one or multiple probes (two in this example) and a motor system. Thus, carriage 62 includes probes/motors 62 A and 62 B, each mounted for movement transverse to the slabline and including a drive motor for imparting probe movement in directions transverse to the longitudinal axis of the signal transmission line 54 , and a carriage motor system 62 C for moving the carriage along the longitudinal axis of the transmission line. By moving the probes closer to or away from the transmission line, the impedance of the transmission line is varied. Limit switches 62 D- 1 and 62 D- 2 are mounted at opposite sides of the carriage 62 to provide position signals which may be used in initialization and collision alert/avoidance of the carriages. Carriage 64 is similarly equipped. Other tuner systems may employ other combinations of elements. Motor drive circuits may reside on a separate circuit board, and respond to commands from the tuner controller.
The tuner 50 includes an integrated controller 80 , and a display 90 . The controller for the tuner has several connectors or ports, in this case a TCP/IP port 82 A, a USB port 82 B, a connector 82 C configured for an SD flash memory card, and a power port 82 D for providing power to the tuner system. The controller 80 may further support additional connectors or ports, e.g. 82 E, 82 F, 82 G, which may provide control signals to other devices in a measurement system, e.g. a signal generator, signal amplifier, power meter, signal analyzer, and the like.
FIG. 1B is a simplified controller functional block diagram, of exemplary functions implemented by the controller 80 . Major functions include tuning control 84 B to create the electronic control signals to control the electronic impedance varying system 20 , tuner characterization algorithms 84 C, calibration algorithms 84 D, measurement algorithms 84 E, and system device drivers 84 F. The system device drivers may include, for example, RF signal generator driver 84 F 1 , RF amplifier driver 84 F 2 , power meter driver 84 F 3 and VNA driver 84 F 4 . The system device drivers are software drivers which allow the tuner controller to also control the operation of measurement system devices. The controller 80 may also include in an exemplary embodiment communication servers 84 G (e.g., Wi-Fi ( 84 G 1 ), Bluetooth ( 84 G 2 ), Telnet ( 84 G 3 ), FTP (file transfer protocol) 84 G 4 and HTTP (Hypertext Transfer Protocol) 84 G 5 ) in this exemplary embodiment), a command interpreter 84 H, TCP/IP socket support 841 and USB support 84 J, and the file system 84 K. The file system may include files such as calibration data 84 K 1 , de-embedding data 84 K 2 , web pages 84 K 3 , JAVA applets 84 K 4 , setup definition data files 84 K 5 , configuration data 82 K 6 and measurement data files ( 85 K 8 ).
The Wi-Fi ( 84 G 1 ) and Bluetooth ( 84 G 2 ) server functions enable wireless communication between a user interface computer device 200 ( FIGS. 3 and 4 ) and the tuner controller, to control operation of the tuner and measurement system. The device 200 can be a smart phone, tablet laptop, desktop computer, or the like.
The HTTP server 84 G 5 delivers web pages on request to the client, and is also used to receive and process content posted back from the client.
The FTP server 84 G 4 allows moving files between external client computers and the file system of the controller over a TCP/IP based network.
The Telnet server 84 G 3 enables bi-directional interactive text-oriented communication over the TCP/IP network.
In an exemplary embodiment, the file system, e.g. a FAT (file allocation table), on the controller non-volatile memory is used to store:
(i) web pages ( 84 K 3 ) and Java applets ( 84 K 4 ) to be sent by the HTTP server to the client, the user interface device ( 200 ); (ii) tuner configuration ( 84 K 6 ) and calibration data ( 84 K 1 ); (iii) s-parameter de-embedding data ( 84 K 2 ) for fixtures and other setup components; (iv) setup definition files ( 84 K 5 ); and (v) firmware files ( 84 K 7 ).
The file system can be remotely accessed via the FTP server over the TCP/IP network established between the tuner controller and a client computer system. Files can be transferred over the network.
HTTP, FTP and Telnet servers are per se well known.
In an exemplary embodiment, the communication servers are running concurrently in the controller 80 , and all incoming requests and postings are forwarded to the command interpreter 84 H which in turn will check the command syntax and initiate appropriate action, such as dispatching tuning commands or returning status information to the client.
The tuning control function 84 B uses tuner calibration and de-embedding data loaded from the file system 84 K to translate tuning commands received from the command interpreter into control signals for the impedance varying system, e.g. motion control signals for electro-mechanical tuners or solid state element control signals for electronic tuners.
The Telnet server may be omitted for applications employing HTTP based tuning control, in which the user-entered data are transmitted back to the tuner from the client using an HTTP protocol (e.g., GET and POST method).
The controller 80 can be configured to run, in an exemplary embodiment, the LXI standard instrument control protocol, described more fully at LXI.org.
The user interface device 200 may be configured to run an HTTP client software application such as a web browser, e.g. Windows Explorer, Mozilla Firefox or Apple Safari. The user utilizes the browser to navigate to the IP address of the tuner (which for convenience can be displayed on the tuner display), using an HTTP channel established between the tuner controller and the device 200 . The browser fetches (from the tuner controller) and displays the tuner main web page (shown in FIG. 6 of the '462 application) that includes several command buttons. Clicking the “TUNER APP” button, for example, will display the tuning web page with an embedded JAVA applet.
FIG. 1C illustrates an alternate embodiment, in which the controller 80 ′ is external to the housing 52 ′ of the impedance tuner 50 ′, and is electrically connected to the tuner 50 ′ through a communication channel 94 such as a USB connection. The controller 80 ′ may be web-enabled, and is otherwise as described above regarding the controller 80 of FIG. 1B .
FIG. 5 is an exemplary screen shot of an exemplary tuner characterization configuration page. Users can define and select drivers for associated instruments, such as a VNA, which are stored on the controller 80 file system. In an exemplary embodiment, only the TUNER APP page embeds a JAVA applet, all other pages are based on HTTP only. The tuner characterization page shows schematic representations of the tuner and the VNA. The DUT is shown only for tuner orientation. If the tuner were to be used on the input of the DUT, it would appear on the left of the DUT; in this example, the tuner is to be used as a load tuner, and is shown on the right of the DUT.
FIG. 6 is an exemplary screen shot of an exemplary tuner characterization measurement data page. The characterization of the tuner as defined earlier is executed by the tuner characterization algorithms ( 84 C), and the resulting data is saved into a table, e.g. for viewing as a Smith chart characterization.
FIG. 7 is an exemplary screen shot of an exemplary system calibration configuration page, showing schematically the signal generator, the tuner and a power meter. Users can define and select drivers for associated instruments. The DUT is replaced with a THRU for calibration.
FIG. 8 is an exemplary screen shot of an exemplary system calibration measurement page. The system calibration algorithm, as defined earlier, is executed and the resulting data is saved into a table, stored in file system 84 K of the controller.
Although the foregoing has been a description and illustration of specific embodiments of the subject matter, various modifications and changes thereto can be made by persons skilled in the art without departing from the scope and spirit of the invention. For example, it is well known that the computer and software technologies advance and change rapidly. Therefore, other software languages, interfaces and communication protocols that either currently exist or may become available in the future could be used in other embodiments of this invention. For example, while the embedded applet has been described above as a JAVA applet, other applets developed with other languages such as C# (Microsoft), F# (Microsoft) could be employed as well. It is also well known that measurement equipment and types of measured data change as technologies advance. For example, a vector receiver or a noise receiver could be used with or instead of the RF source and power meter described herein, e.g., with respect to FIGS. 3, 4 and 7 .
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An impedance tuner system, usable in a measurement system including at least one measurement system device, the tuner system comprising the impedance tuner having a signal transmission line, and an impedance-varying system coupled to the transmission line, and responsive to command signals to selectively vary the impedance presented by the impedance tuner. An impedance tuner controller is configured to generate the command signals, and wherein measurement device drivers and at least one of characterization, calibration and measurement algorithms are embedded into the tuner controller, the tuner controller configured to allow a user to control execution of said at least one of the characterization, calibration and measurement algorithms using the tuner controller.
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TECHNICAL FIELD
[0001] The present invention relates to a foam dispenser.
BACKGROUND ART
[0002] Various types of foam dispensers have been proposed which includes a cylinder member suspended in a container body, the cylinder member having an upper large-diameter cylinder and a lower small-diameter cylinder. An upwardly-urged actuator is provided to project from the cylinder member, and a foaming member is fitted into the actuator. In this instance, depression of the actuator causes a content liquid within the small-diameter cylinder and air inside the large-diameter cylinder to pass through the foaming member so as to be foamed and discharged from a nozzle. (Refer to Patent Literature 1, for example.)
[0003] Manufacturing of such a conventional foam dispenser requires first of all a simple die structure for molding, and therefore, it has been a conventional practice that a dispenser head constituting an upper end of the actuator is formed as a single part with a large thickness.
CITATION LIST
Patent Literature
[0004] PTL 1: JPH08230961A
SUMMARY OF THE INVENTION
Technical Problems
[0005] Due to the above reason, the conventional foam dispenser suffers from a problem that the liquid passage and other elements are restricted in size, and a large outlet cannot be achieved without significantly enlarging the dispenser head itself and thereby increasing the manufacturing cost.
[0006] The present invention has been conceived in view of these problems and aims to provide a foam dispenser which makes it possible to realize a dispenser head structure with a minimum thickness to thereby increase the dispensing amount.
Solution to Problems
[0007] A first aspect of the present invention resides in a foam dispenser, comprising: a cylinder member B that includes: an upper end portion adapted to be secured to a placing cap A fitted over an outer circumference of a neck 101 of a container body 100 so that the cylinder member B is suspended in the container body 100 ; a large-diameter air cylinder 20 ; and a small-diameter liquid cylinder 21 provided concentrically with and below the large-diameter air cylinder 20 ; and an actuator C that includes: a stem 30 ; a liquid piston 35 protruding from a lower portion of a circumference of the stem 30 and adapted to slide in the liquid cylinder 21 ; an air piston 40 linked to the outer circumference of the stem 30 and adapted to slide in the air cylinder 20 ; and a dispenser head 50 fitted over an upper end of the stem 30 , the actuator C being urged upward and adapted to be displaceable upward and downward such that the upward and the downward displacement of the actuator C causes a liquid within the liquid cylinder 21 and air within the air cylinder 20 to be mixed and foamed to be dispensed as a foam from an outlet of the dispenser head 50 ; wherein the dispenser head 50 comprises two members in the form of a first member 50 a and a second member 50 b, the first member 50 a including: a top plate 51 ; a longitudinal tube 52 suspending from a middle portion of a back surface of the top plate 51 and including a lower portion fitted around an outer circumference of an upper portion of the stem 30 ; and a nozzle 53 provided on the longitudinal tube 52 to protrude forward, the nozzle 53 including an open base end whose top portion in part constitutes the top plate 51 , and the second member 50 b including: a ring-shaped top plate portion 60 ; a vertical wall portion 61 suspending from an outer circumference of the top plate portion 60 ; a circumferential wall portion 62 suspending from an inner circumference of the top plate portion 60 ; a first fitting recess 63 provided in a front portion of the top wall portion 60 and the vertical wall portion 61 ; and a second fitting recess 64 provided along the inner circumference of the top plate portion 60 that is in contiguity with the first fitting recess 63 , the first and the second member 50 a and 50 b being integrated by fitting the base end of the nozzle 53 to the first fitting recess 63 and fitting an outer circumference of the top plate 51 to the second fitting recess 64 .
[0008] A second aspect of the present invention resides in the foam dispenser according to the first aspect, wherein a fitting hole 65 is provided in each of a bottom wall portion of the first fitting recess 63 and a bottom wall portion of the second fitting recess 64 , and a hook 55 is provided to protrude from each of a lower surface of the nozzle 53 and a lower surface of the top plate 51 in correspondence with the fitting holes 65 so as to be hooked into the fitting holes 65 , the fitting holes 65 and the hooks 55 together forming an engagement member.
[0009] A third aspect of the present invention resides in the foam dispenser of one of the first and the second aspect, wherein the second fitting recess 64 of the second member 50 b is further recessed to form an annular drain recess 67 provided with a drain hole 68 .
[0010] A fourth aspect of the present invention resides in the foam dispenser according to the third aspect, wherein the dispenser head 50 has a top surface constituted by the first and the second member 50 a and 50 b, the top surface being inclined downward from a front to a rear of the dispenser head 50 , and the nozzle 53 and the bottom wall portion of the first fitting recess 63 and the bottom wall portion of the second fitting recess 64 are inclined downward from the front to the rear.
[0011] A fifth aspect of the present invention resides in the foam dispenser of any one of the first to fourth aspect, wherein a support plate 56 is provided to extend across an upper portion of the circumferential wall portion 62 .
Advantageous Effects of Invention
[0012] According to the present invention, since the dispenser head 50 includes the two members, i.e., the first and the second member 50 a and 50 b, which include the abovementioned unique structure, thicknesses of the first and the second member 50 a and 50 b are advantageously minimized, and the outlet and the dispenser passage can be enlarged while the conventional overall structure is maintained. Furthermore, the minimized thicknesses result in a reduced amount of material used, and moreover, the minimized thicknesses offer a manufacturing advantage that assembly of the first member and the second member 50 a and 50 b is significantly facilitated due to the structures thereof.
[0013] When the fitting hole 65 is provided in each of the bottom wall portion of the first fitting recess 63 and the bottom wall portion of the second fitting recess 64 , and the hook 55 is provided to protrude from each of the lower surface of the nozzle 53 and the lower surface of the top plate 51 in correspondence with the fitting holes 65 so as to be hooked into the fitting holes 65 , the fitting holes 65 and the hooks 55 together forming an engagement member, it is ensured that the first and the second member 50 a and 50 b are easily engaged.
[0014] When the second fitting recess 64 of the second member 50 b is further recessed to form the annular drain recess 67 provided with the drain hole 68 , even when water is permeated from where the two members constituting the dispenser head 50 are engaged, the permeated water can be discharged outside of the circumferential wall portion 62 from the drain hole 68 . As a result, inconvenience, such as permeation of the water into the air cylinder 20 through the longitudinal tube 52 , is prevented, for example.
[0015] When the dispenser head 50 has the top surface constituted by the first and the second member 50 a and 50 b, the top surface being inclined downward from the front to the rear of the dispenser head 50 , and the nozzle 53 and the bottom wall portion of the first fitting recess 63 and the bottom wall portion of the second fitting recess 64 are inclined downward from the front to the rear, even when the water around the top surface of the dispenser head 50 is permeated from where an outer circumference of the top plate 51 and an inner circumference of the top plate portion 60 are joined, the water can flow rearward through the drain recess 67 to be smoothly discharged outside from the drain hole 68 at rear of the drain recess 67 .
[0016] When the support plate 56 is provided to extend across the upper portion of the circumferential wall portion 62 , stiffness of the dispenser head 50 formed in the minimized thickness is further increased, which further ensures that the risk of deformation and the like is prevented.
BRIEF DESCRIPTION OF DRAWINGS
[0017] The present invention will be further described below with reference to the accompanying drawings, wherein:
[0018] FIG. 1 is a longitudinal sectional view showing a foam dispenser according to a first embodiment;
[0019] FIG. 2 is a plan view showing a dispenser head of the foam dispenser of the first embodiment;
[0020] FIG. 3 is a cross-sectional view showing a longitudinal tubular portion of a first member of the first embodiment;
[0021] FIG. 4 is longitudinal sectional view showing part of the foam dispenser taken along a line x-x shown in FIG. 3 of the first embodiment;
[0022] FIG. 5 is a cross-sectional view showing the longitudinal tubular portion of the first member according to a second embodiment;
[0023] FIG. 6 is a longitudinal sectional view showing the foam dispenser according to a third embodiment;
[0024] FIG. 7 is a longitudinal sectional view showing the foam dispenser of the third embodiment; and
[0025] FIG. 8 is a plan view showing the dispenser head of the foam dispenser of the third embodiment.
DESCRIPTION OF EMBODIMENTS
[0026] Embodiments of the present invention are described below with reference to the drawings.
[0027] FIGS. 1 and 2 show an example of a foam dispenser 1 including a placing cap A, a cylinder member B, an actuator C, a poppet valve body D, and a spacer E.
[0028] The placing cap A is used to fasten the foam dispenser 1 to a container body 100 . The placing cap A includes a circumferential wall 10 having an upper edge fitted to an outer circumference of a neck 101 of the container body 100 , a top wall 11 extending from the upper edge of the circumferential wall 10 and provided in a middle portion thereof with a window hole through which the actuator C extends, and a guide tube 12 extending upward from a circumferential portion of the window hole.
[0029] The cylinder member B includes a large-diameter air cylinder 20 having an upper end secured to a circumferential portion of a back surface of a top portion the placing cap A, along with a small-diameter liquid cylinder 21 extending concentrically with and below the air cylinder 20 . The liquid cylinder 21 is configured to include a bottom wall portion whose front surface serves as a valve seat. The liquid cylinder 21 also includes an integrally-formed pipe fitting tube extending downward from a periphery of a central opening of the bottom wall portion. There is also provided a suction pipe 22 including an upper end fitted to the pipe fitting tube and a lower end suspended to reach a lower end portion of the container body 100 . Furthermore, a plurality of engagement ribs 23 is projectingly provided circumferentially in a portion of an inner surface of the liquid cylinder 21 starting from a peripheral portion of the bottom wall portion and extending to a lower end portion of a circumferential wall portion of the liquid cylinder 21 . Each engagement rib 23 includes an upwardly stepped portion in a middle portion between a top and a bottom of the engagement rib 23 .
[0030] The actuator C is mounted to the cylinder member B such that the actuator C is urged upward and displaceable upward and downward. The actuator member C includes a stem 30 , a liquid piston 35 , an air piston 40 , a dispenser head 50 , and a tubular member 70 .
[0031] The stem 30 has a tubular shape with open upper and lower ends. The liquid piston 35 , which is adapted to slide in the liquid cylinder 35 , is provided to protrude from the lower portion of the outer circumference of the stem 30 . The air piston 40 , which is adapted to slide in the air cylinder 20 , is linked to an upper portion of the outer circumference of the stem 30 . Thus, the stem 30 is provided to be displaceable upward and downward in the liquid cylinder 35 and in the air cylinder 20 . Inside the stem 30 in an upper portion thereof, a dispenser valve 31 is provided, and a plurality of longitudinal ridges 32 is also provided circumferentially below the dispenser valve 31 . Furthermore, on an outer surface of the stem 30 , an air dispenser valve seat 33 is provided to protrude in a flange shape.
[0032] The liquid piston 35 includes a fitting tubular portion 36 fitted in a lower portion of the stem 30 , and a sliding portion 37 in a skirt shape that protrudes outward from an outer circumference of a lower end of the fitting tubular portion 36 , to with the sliding portion 37 slidably fitted to an inner circumference of the liquid cylinder 21 in a liquid-tight manner. The fitting tubular portion 36 forms, at an upper end portion thereof in a middle portion between the top and the bottom of the stem 30 , a ridge-shaped check valve seat 38 . There is also interposed a coil spring s between a lower surface of the fitting tubular portion 36 of the liquid piston 35 and the upwardly stepped portion of each engagement rib 23 , so that the actuator C is constantly urged upward by the coil spring s.
[0033] The air piston 40 includes a tubular valve portion 41 provided in an inner circumference thereof and fitted to the outer circumference of the stem 30 so as to be gradually displaceable upward and downward, and a sliding portion 43 composed of an upper and a lower skirt-like portion and fitted to an inner circumference of the air cylinder 20 , and a stepped wall portion 42 extending from an outer circumference of the tubular valve portion 41 to the sliding portion 43 . The tubular valve portion 41 and the air dispenser valve seat 33 together form an air dispenser valve 44 . The air dispenser valve 44 is closed when the actuator C is displaced to an uppermost position, opened when the actuator C is depressed down, and closed when the actuator C is displaced upward from the depressed position by the upward urging force. Furthermore, there is provided an outer-air introducing valve 45 in the stepped walled portion 42 of the air piston 40 , for introducing an outer air. The outer-air introducing valve 45 includes a valve hole 46 pierced through the stepped wall portion 42 and a valve plate 47 pressed against the stepped wall portion 42 , and when upward displacement of the depressed actuator C creates a negative pressure in the air cylinder 20 , the outer-air introducing valve 45 is opened for introducing the outer air. The outer-air introducing valve 45 also includes a wall portion 48 standing on an upper surface of the stepped wall portion 42 except for an outer periphery of the valve hole 46 , so the wall portion 48 prevents a liquid from permeating the air cylinder 20 even when the liquid is permeated through the guide tube 12 .
[0034] The dispenser head 50 includes two members, i.e., a first member 50 a and a second member 50 b, that are easy to cut out with a die and can be formed in a small thickness during molding.
[0035] The first member 50 a includes a top plate 51 , a longitudinal tube 52 suspending from a middle portion of a back surface of the top plate 51 and fitted around an outer circumference of an upper portion of the stem 30 , and a nozzle 53 provided on the longitudinal tube 52 to protrude forward and including an open base end. A top portion of the base end of the nozzle 53 in part constitutes the top plate 51 . The longitudinal tube 52 includes, in an upper portion thereof, a large-diameter first stepped portion 52 a, and also includes, in a middle portion between a top and a bottom thereof, a plurality of elongated strip-shaped protrusions 52 b circumferentially arranged to bulge out. Each strip-shaped protrusion 52 b protrudes such that an outer surface of the strip-shaped protrusion 52 b is in proximity to an inner surface of the guide tube 12 . The longitudinal tube 52 also includes a second stepped portion 52 c extending from a lower end portion of each strip-shaped protrusion 52 b, the second stepped portion 52 c having an even larger diameter. Furthermore, there is provided a plurality of ribs 54 protruding from an outer surface of the longitudinal tube 52 between adjacent strip-shaped protrusions 52 b. In the present embodiment, as shown in FIG. 3 , one rib 54 protrudes between each strip-shaped protrusion 52 b, and as shown in FIG. 4 , an outer edge of the rib 54 is in proximity to the inner surface of the guide tube 12 . Note that the number of the ribs 54 is not limited to the present embodiment, and two or another number of ribs 54 may be protruded between each strip-shaped protrusion 52 b as shown in FIG. 5 . Furthermore, the number of strip-shaped protrusions 52 b is not limited to four as illustrated in the figures. Moreover, there is provided a hook 55 protruding from each of a lower surface of the nozzle 53 and a lower surface of the top plate 51 .
[0036] The second member 50 b includes a ring-shaped top plate portion 60 , a vertical wall portion 61 suspending from an outer circumference of the top plate portion 60 , and a circumferential wall portion 62 suspending from an inner circumference of the top plate portion 60 . Furthermore, the second member 50 b includes, for fitting the base end of the nozzle 53 , a first fitting recess 63 in a front portion the second member 50 b, and also includes, for fitting an outer circumference of the top plate 51 , a second fitting recess 64 in contiguity with first fitting recess 63 . Accordingly, the first fitting recess 63 has a linear shape with a large longitudinal width, and the second fitting recess 64 has a substantially annular shape with a longitudinal width as small as a material thickness. Furthermore, the second member 50 b includes a fitting holes 65 in each of a bottom wall portion of the first fitting recess 63 and a bottom wall portion of the second fitting recess 64 that correspond to the hooks 55 when the second member 50 b is fitted to the first member 50 a, and the fitting holes 65 and the hooks 55 together form an engagement member.
[0037] The first and the second member 50 a and 50 b are fixedly fitted to each other, with each hook 55 engaged in the corresponding engagement hole 65 , and thus the dispenser head 50 is formed. Furthermore, the tubular member 70 as a partition wall having a small-diameter tower portion is fitted below the first stepped portion 52 a of the dispenser head 50 so as to fit a lower portion of the longitudinal tube 52 around the outer circumference of the upper portion of the stem 30 . The air cylinder 20 and the stem 30 are in communication via an air passage 66 that passes between the stem 30 and the longitudinal tube 52 to communicate with an inside of the stem 30 below the tubular member 70 , and a gas-liquid mixing chamber R is defined between the tubular member 70 and the dispenser valve 31 . Furthermore, a lower end of the circumferential wall portion 62 is suspended to a position of an upper end portion of an outer circumference of the guide tube 12 such that a ridged end face of the circumferential wall portion 62 abuts against or is in proximity to a ridged end face of the guide tube 12 . In the dispenser head 50 , a top surface constituted by the first and the second member 50 a and 50 b is inclined downward from front to rear, and accordingly, the entire nozzle 53 is similarly inclined. The bottom wall portion of the first fitting recess 63 and the bottom wall portion of the second fitting recess 64 are also similarly inclined.
[0038] In a downstream of the gas-liquid mixing chamber R, a forming member 71 is provided. The foaming member 71 in the present embodiment includes a pair of tubular bodies 71 b in which meshes 71 a are stretched, and the foaming member 71 is fitted in the tubular member 70 such that the meshes 71 a are arranged on top and bottom.
[0039] The poppet valve body D has a length extending from an inside of the liquid cylinder 21 to the stem 30 and includes a plurality of engagement protrusions 75 circumferentially provided in a lower end portion of an outer circumference thereof. One engagement protrusions 75 is positioned between each engagement rib 23 of the liquid cylinder 21 . A circumference of a lower surface of each engagement protrusion 75 is tapered so as to form a suction valve 76 in cooperation with a suction valve seat formed by a bottom surface of the liquid cylinder 21 . The poppet valve body D is displaceable upward and downward from a position where the lower surface abuts against the suction valve seat to a position where each engagement protrusion 75 abuts against a lower surface of the coil spring s. The poppet valve body D also includes, at a top thereof, a check valve body 77 spreading in a tapered s tubular shape, and the check valve body 77 and the check valve seat 38 together form a check valve 78 .
[0040] The spacer E includes a fitting portion 80 of a circular-arc plate shape detachably fitted to the outer circumference of the guide tube 12 , and a knob portion 81 of a plate shape protruding rearward from a rear surface of the fitting portion 80 . When fitted, the fitting portion 80 of the spacer E abuts against a lower surface of the circumferential wall portion 62 of the dispenser head 50 so as to prevent the actuator C from being depressed. The fitting portion 80 is forced to be fitted to the outer circumference of the guide tube 12 by elastically spreading the fitting portion 80 .
[0041] From the state of the foam dispenser 1 shown in FIG. 1 , by removing the spacer E and depressing the dispenser head 50 , the air piston 40 is displaced upward relative to the stem 30 , and the air dispenser valve 44 is opened. As the air piston 40 is displaced downward, an air inside the air cylinder 20 is pressurized to be introduced into the gas-liquid mixing chamber R via the air passage 66 . On the other hand, the stem 30 is depressed downward, thereby displacing the poppet valve body D downward until the poppet valve body D comes into abutment against the suction valve seat. As the poppet valve body D is displaced upward relative to the stem 30 and the check valve 78 is opened, a pressurized liquid inside the liquid cylinder 21 is introduced into the gas-liquid mixing chamber R via the dispenser valve 31 . The air and the liquid are mixed in the gas-liquid mixing chamber R. In this regard, the poppet valve body D is displaced upward relative to the stem 30 while the check valve body 77 of the poppet valve body D is in sliding contact with an inner surface of each longitudinal ridge 32 of the stem 30 . The mixed gas and liquid in the gas-liquid mixing chamber R passes through the foaming member 71 to be foamed and dispensed from the nozzle 53 as foam.
[0042] When the dispenser head 50 is released, the actuator C is displaced upward by the upward urging force of the coil spring s. At this time, the air piston 40 is displaced downward relative to the stem 30 to close the air dispenser valve 44 , thereby creating the negative pressure in the air cylinder 20 . As a result, the outer air introducing valve 45 is opened, and the outer air is introduced into the air cylinder 20 . On the other hand, upward displacement of the stem 30 displaces the poppet valve body D upward by a friction force generated between the check valve body 77 and each longitudinal ridge 32 , As a result, the suction valve 76 is opened, and the liquid within the container body 100 is introduced into the liquid cylinder 21 under the negative pressure, while the dispenser valve 31 is closed. The poppet valve body D is displaced upward until the engagement protrusions 75 thereof come into abutment with the lower surface of the coil spring s and subsequently displaced downward relative to the stem 30 until the check valve body 77 comes into abutment with the check valve seat 38 .
[0043] FIGS. 6-8 show another embodiment in which the second fitting recess 64 of the second member 50 b in the embodiment shown in FIG. 1 is further recessed to form an annular drain recess 67 provided with a drain hole 68 . In the present embodiment, the fitting hole 65 doubles as the drain hole 68 . Furthermore, the first fitting recess 63 is provided with the drain hole 68 as well. The drain holes 68 of the first and the second fitting recess 63 and 64 may be independently provided. In this case also, the top surface of the dispenser head 50 that is constituted by the first and the second member 50 a and 50 b is inclined downward from front to rear, and the lower surface of the nozzle 53 is also inclined from front to rear. Accordingly, the bottom surfaces of the first and the second fitting recess 63 and 64 , as well as a lower surface of the drain recess 67 , are inclined from front to rear.
[0044] Moreover, there are provided support plates 56 in an upper portion of the circumferential wall portion 62 , for providing support. As shown in FIG. 8 , the support plates 56 in the illustrated embodiment include a front-part lateral support plate 56 a protruding from left and right sides of the base end of the nozzle 53 in a lateral direction, an intermediate-part lateral support plate 56 b protruding from the left and right sides of the longitudinal tube 52 in the lateral direction, a rear-part lateral support plate 56 c extending downward from the top plate 51 in rear of the longitudinal tube 52 with a space therebetween, a front-part longitudinal support plate 56 d protruding forward from a front portion of the longitudinal tube 52 on the bottom surface of the nozzle 53 , and a rear-part longitudinal support plate 56 e of a substantially L-shape protruding rearward from a rear portion of the longitudinal tube 52 and then bent upward to be coupled to the top plate 51 . In this instance, the terms “lateral” and “longitudinal” in connection with these support plates 56 a - 56 e refer, respectively, to the lateral and longitudinal directions of the nozzle 53 itself. The rear-part longitudinal support plate 56 e is also coupled to the rear-part lateral support plate 56 c. The support plates 56 are integrally formed with the first member 50 a and are extended across the circumferential wall portion 62 such that the support plates 56 are fixed at outer peripheries thereof to opposing sides of the circumferential wall portion 62 by pressure contact, engagement, and the like. It is suffice to provide at least one of the support plates 56 , and a shape and a position thereof may be determined according to a desired stiffness. Other structures are similar to those of the embodiment shown in FIG. 1 , and a description thereof is omitted here. Furthermore, the support plates 56 may be extended between the circumferential wall portion 62 and the vertical wall portion 61 .
[0045] Meanwhile, the aforementioned members are mainly made of synthetic resin, and a metal, a flexible elastomer, and the like may also be used in combination as appropriate.
REFERENCE SIGNS
[0046] 1 Foam dispenser
[0047] A Placing cap
[0048] 10 Circumferential wall
[0049] 11 Top wall
[0050] 12 Guide tube
[0051] B Cylinder member
[0052] 20 Air cylinder
[0053] 21 Liquid cylinder
[0054] 22 Pipe
[0055] 23 Engagement rib
[0056] C Actuator
[0057] 30 Stem
[0058] 31 Dispenser valve
[0059] 32 Longitudinal ridge
[0060] 33 Air dispenser valve seat
[0061] 35 Liquid piston
[0062] 36 Fitting tubular portion
[0063] 37 Sliding portion
[0064] 38 Check valve seat
[0065] 40 Air piston
[0066] 41 Tubular valve portion
[0067] 42 Stepped wall portion
[0068] 43 Sliding portion
[0069] 44 Air dispenser valve
[0070] 45 Outer-air introducing valve
[0071] 46 Valve hole
[0072] 47 Valve plate
[0073] 48 Wall portion
[0074] R Gas-liquid mixing chamber
[0075] 50 Dispenser head/First member
[0076] 51 Top plate
[0077] 52 Longitudinal tube
[0078] 52 a First stepped portion
[0079] 52 b Strip-shaped protrusion
[0080] 52 c Second stepped portion
[0081] 53 Nozzle
[0082] 54 Rib
[0083] 55 Hook
[0084] 56 Support plate
[0085] 56 a Front-part lateral support plate
[0086] 56 b Intermediate-part lateral support plate
[0087] 56 c Rear-part lateral support plate
[0088] 56 d Front-part longitudinal support plate
[0089] 56 e Rear-part longitudinal support plate
[0090] 50 b Second member
[0091] 60 Top plate
[0092] 61 Vertical wall portion
[0093] 62 Circumferential wall portion
[0094] 63 First fitting recess
[0095] 64 Second fitting recess
[0096] 65 Fitting hole
[0097] 66 Air passage
[0098] 67 Drain recess
[0099] 68 Drain hole
[0100] 70 Tubular member
[0101] 71 Foaming member
[0102] 71 a Mesh
[0103] 71 b Tubular body
[0104] D Poppet valve body
[0105] 75 Engagement protrusion
[0106] 76 Suction valve
[0107] 77 Check valve body
[0108] 78 Check valve
[0109] E Spacer
[0110] 80 Fitting portion
[0111] 81 Knob portion
[0112] S Coil spring
[0113] 100 Container body
[0114] 101 Neck
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Provided is a foam dispenser in which upward and downward displacement of an actuator causes a content liquid within a liquid cylinder and air within an air cylinder to be mixed and foamed, such that the foam so generated is dispensed from an outlet of a dispenser head. The dispenser head has a structure with a minimized thickness to thereby increase the dispensing amount. The dispenser head includes two members, i.e., a first member and a second member, that have special configuration for allowing the two members to be easily removed from a die and formed in a small thickness.
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CROSS REFERENCES TO RELATED APPLICATIONS
Not Applicable
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to magnetomechanical electronic article surveillance systems and methods, and more particularly to the generation and detection of sideband signals from a magnetomechanical marker.
2. Description of the Related Art
Electronic article surveillance (EAS) systems are well known for the prevention or deterrence of unauthorized removal of articles from a controlled area. In a typical EAS system, markers designed to interact with an electromagnetic field located at the exits of the controlled area are attached to articles to be protected. If a marker is brought into the electromagnetic field or “interrogation zone”, the presence of the marker is detected and appropriate action is taken, such as generating an alarm.
Several types of EAS systems and markers are presently known. In one type, the marker includes either an antenna and diode, or an antenna and capacitors forming a resonant circuit. When placed in an electromagnetic field transmitted by the interrogation apparatus, the marker having an antenna and diode generates harmonics of the interrogation frequency in the receive antenna; the resonant circuit marker causes an increase in absorption of the transmitted signal so as to reduce the signal in the receiving coil. Detection of the harmonics or the signal level change in the receive coil indicates the presence of the marker.
One of the problems with harmonic generating markers and resonant circuit markers is the difficulty with detection at remote distances. Another problem with harmonic generating and resonant circuit markers is the difficulty in distinguishing the marker signal from pseudo signals generated by other items such as belt buckles, pens, hair clips, and other metallic objects.
U.S. Pat. No. 4,660,025 discloses an improved harmonic generating marker utilizing a magnetic material having a magnetic hysteresis loop that exhibits a large Barkhausen discontinuity. The magnetic material, when exposed to an external magnetic field whose field strength in the direction opposing the instantaneous magnetic polarization of the material exceeds a predetermined threshold value, results in a regenerative reversal of the magnetic polarization of the material. The result of utilizing markers having magnetic material exhibiting a large Barkhausen discontinuity is the production of high order harmonics having amplitudes that are more readily detected. However, false alarms are still possible utilizing these improved harmonic generating markers.
Harmonic generating markers rely on non-linear behavior of the magnetic materials to generate the harmonic signals needed for detection. A more robust EAS system utilizes magnetomechanical or magnetoacoustic markers in which magnetic resonators operate in a linear magnetic response region.
U.S. Pat. Nos. 4,510,489 and 4,510,490 each disclose an electronic article surveillance (EAS) system and associated magnetomechanical marker. The magnetomechanical marker includes a resonator element made of a magnetostrictive material, which in the presence of a biasing magnetic field, resonates in response to a specific frequency. The biasing magnetic field is typically provided by a ferromagnetic element disposed adjacent the magnetostrictive material. Upon being magnetized, the ferromagnetic element provides a biasing magnetic field that enables the magnetostrictive material to resonate at its preselected resonance frequency. The marker is detected by detecting the change in coupling between an interrogating coil and a receiving coil at the marker's resonant frequency.
Because the marker is interrogated and detected at the marker's resonant frequency, the transmitted interrogation frequency interferes with detection of the marker. Therefore, a burst or pulsed magnetomechanical EAS system is preferred. In the pulsed system, a transmitter generates a signal at a preselected frequency, such as 58 kHz, for a fixed duration to excite the marker. The receiver is disabled for the transmit period. The receiver is then activated to detect the resonant envelope of the marker as it decays over time, commonly referred to as “ring-down”. A marker having a high quality factor (Q) response is required for good detection in a pulsed system, resulting in few false alarms and detection from remote distances. While, a pulsed magnetomechanical is the highest quality and highest functioning EAS system available to date, there is room for improvement.
After a transmit pulse is generated, the receiver typically includes an initialization period after activation which causes the receiver's detection window to be delayed slightly. In addition, due to the finite length of the transmit pulse, the marker may not have sufficient time to build up full energy before the transmitter is deactivated, and the marker may begin to ring-down from a lower energy level. The detection window is thus shifted to a time when the marker has already lost some of its available stored energy, making detection more difficult. An improved signal generation and detection method for magnetomechanical markers is desired.
BRIEF SUMMARY OF THE INVENTION
Sideband detection can be an improvement over harmonic and field disturbance detection. In the detection of harmonics, or in detection of the fundamental frequency, the carrier signal itself is a source of noise. The signals that are being detected from an EAS marker are small, so even a small amount of carrier noise masks the desired signal. With sideband detection, the carrier frequency is not a significant noise source masking the detection of the sidebands.
In a first aspect of the present invention, an electronic article surveillance system using a magnetomechanical marker for generating and detecting modulated signals is provided. A first signal at a first frequency and a second signal at a second frequency are transmitted into an interrogation zone. The second frequency is a magnetic field lower in frequency than the first frequency. A magnetomechanical marker having a magnetostrictive material is attached to an article that passes through the interrogation zone. The magnetostrictive material of the marker resonates at the first frequency when biased to a predetermined level by a magnetic field. The second signal is a low frequency magnetic field that effects the bias of the marker causing the resonant frequency of the marker to shift about the first frequency according to the second signal's low frequency alternating magnetic field. In terms of modulation, the first signal is a carrier signal, and the second signal is a modulation signal for the modulation of the two signals performed by the marker. The modulated signals form sidebands of the first frequency offset from the first, or carrier frequency by multiples of the second, or modulation frequency. Detection of the sideband signal by suitable receiving equipment indicates the presence of the marker in the interrogation zone.
In a second aspect of the present invention, a method of enhancing the detection of a magnetomechanical electronic article surveillance (EAS) marker of a type having a magnetostrictive ferromagnetic element that resonates at a preselected frequency when exposed to a biasing magnetic field is provided. The method includes transmitting a first signal at a first frequency and a second signal at a second frequency into an interrogation zone. The second signal is lower in frequency than the first signal. Providing an EAS marker in the interrogation zone having a magnetostrictive material that resonates at the first frequency when biased to a predetermined level by a magnetic field. The second signal is a low frequency magnetic field that causes the resonant frequency of the marker to shift about the first frequency according to the second signal's alternating magnetic field resulting in the modulation of the first signal and the formation of sidebands of the first frequency. Detection of a sideband indicates the presence of a valid marker in the interrogation zone.
In the above aspects of the present invention, the biasing magnetic field for the magnetostrictive material can be a transmitted magnetic field, such as produced by utilizing the second signal, or a different transmitted magnetic field. Preferably the biasing magnetic field is a dc magnetic field which can be implemented by a magnetizable ferromagnetic member disposed adjacent the magnetostrictive material. The ferromagnetic member provides the biasing dc magnetic field when magnetized.
In one embodiment of the present invention, the first frequency is about 58 kHz, and the second frequency is about 200 Hz. While these frequencies are one example, other frequencies can be implemented. The first and second signals can be continuous wave (CW) and the sideband detection can be performed synchronously with the transmission of the first and second signals. Synchronous detection eliminates the need for complex switching in the transmitter or receiver. Alternately, the first signal, the second signal, or both signals can be pulsed. In addition, the magnetostrictive ferromagnetic material of the marker mixes the first and second signals in a linear magnetic response region of the material.
Accordingly, it is an object of the present invention to provide a magnetomechanical EAS system of the type having a magnetostrictive material that resonates at a first frequency when biased by a magnetic field, and that mixes the first frequency and a second frequency producing a detectable sideband of the first frequency.
It is a further object of the present invention to provide a magnetomechanical EAS system of the type having a magnetostrictive material that resonates at a first frequency when biased by a magnetic field, and that in a linear magnetic response region, mixes the first frequency and a second frequency producing a detectable sideband of the first frequency.
It is yet another object of the present invention to provide a method of enhancing the detection of a magnetomechanical electronic article surveillance (EAS) marker of a type having a magnetostrictive ferromagnetic element that resonates at a preselected frequency when exposed to a biasing magnetic field, and that mixes the first frequency and a second frequency producing a detectable sideband of the first frequency.
Other objectives, advantages, and applications of the present invention will be made apparent by the following detailed description of the preferred embodiment of the invention.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
FIG. 1 is a block diagram of an electronic article surveillance system incorporating the present invention.
FIG. 2 is an exploded perspective view of one embodiment for a marker in accordance with the present invention.
FIG. 3 is a graph showing a BH loop for one embodiment of a magnetostrictive ferromagnetic resonator used with the present invention.
FIG. 4 is a graph showing the resonant frequency of the resonator of FIG. 3 as a function of external magnetic field strength.
FIG. 5 is a graph showing the amplitude of the signal from the resonator of FIG. 4 as a function of external magnetic field strength.
FIG. 6 is a graph showing the quality factor Q of the resonator of FIG. 4 as a function of external magnetic field strength.
FIG. 7 is a graph showing the frequency response of a marker in accordance with the present invention.
FIG. 8 is a graph showing the mixing response of a marker in accordance with the present invention on a 58 kHz carrier frequency and a 200 Hz modulating signal.
FIG. 9 is a graph showing the mixing response of a marker in accordance with the present invention on a 58 kHz carrier frequency and a 200 Hz modulating signal having a higher field strength than that of FIG. 8 .
FIG. 10 is a graph showing the signal ratio of the fundamental and its sidebands as a function of the low frequency modulating signal amplitude.
FIG. 11 is a graph of the response of a marker in accordance with the present invention to a swept carrier frequency.
FIG. 12 is a graph of the response of the first sideband as a function of the carrier frequency of a marker in accordance with the present invention.
FIG. 13 is a block diagram of an alternate embodiment of an electronic article surveillance system incorporating the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1, an EAS system in accordance with the present invention is illustrated generally at 10 , comprising a magnetomechanical marker 2 , a resonant frequency transmitter 4 , a low frequency transmitter 6 , an interrogation zone 7 , and a receiver 8 . Interrogation zone 7 is typically positioned in the exit of a controlled area to prevent removal of items to which marker 2 may be attached. As fully described below, resonant frequency transmitter 4 and low frequency transmitter 6 both transmit into interrogation zone 7 . When an active magnetomechanical marker 2 is placed into the interrogation zone 7 , the marker generates sidebands due to the marker's mixing of the two transmitted frequencies. At least one sideband is detected by receiver 8 , indicating the presence of marker 2 in the interrogation zone 7 .
Referring to FIG. 2, magnetomechanical marker 2 includes a resonator 12 made of a magnetostrictive ferromagnetic material adapted to resonate mechanically at a preselected resonance frequency when biased by a magnetic field. The frequency transmitted by transmitter 4 is preselected to be about the resonant frequency of marker 2 . In one embodiment, biasing element 14 , disposed adjacent to resonator 12 , is a high coercive ferromagnetic element that upon being magnetized, magnetically biases resonator 12 permitting it to resonate at the preselected resonance frequency. Alternately, instead of biasing element 14 , resonator 12 can be biased by a low frequency magnetic field transmitted by transmitter 6 , or by a different magnetic field (not shown). Resonator 12 can be placed into cavity 16 in housing member 18 to prevent interference with the mechanical resonance. Further details on marker 2 are available in U.S. Pat. Nos. 4,510,489 and 4,510,490.
Referring to FIG. 3, a representative electric-magnetic field (BH) loop is illustrated for the magnetostrictive material of resonator 12 with the B axis in the vertical direction and the H axis in the horizontal direction, as known in the art. While many alternate sized resonators can be annealed and implemented in accordance with the present invention, in one example, resonator 12 is a magnetic ribbon about 0.5 inches wide and about 1.5 inches long that is annealed in a magnetic field having a transverse anisotropy of about 9 oersted (Oe). The B-H loop measurement of FIG. 3 shows that the 1.5-inch piece saturates at about +/−14 Oe, and is substantially linear between the saturation points, as indicated at 20 .
The resonant frequency of the ribbon illustrated in FIG. 3 is dependent upon the level of the external dc magnetic field applied, as illustrated in FIG. 4 . The resonance starts at about 60.6 kHz, and gradually decreases with the increase of the magnetic field, reaching a minimum of 355 kHz at about 12 Oe. The frequency then increases quickly toward 60.5 kHz as the material reaches its magnetic saturation.
Referring to FIG. 5, the A 1 signal amplitude as a function of the external magnetic field strength is illustrated. The A 1 amplitude is the marker signal output measured 1 millisecond after the excitation transmitter is turned off. The amplitude increases with the magnetic field strength, reaching a maximum of about 3.2 nWb at about 7.4 Oe field. The signal then decreases gradually with further increase in the dc magnetic field toward saturation. For proper marker operation, the resonator 12 needs to be biased at about 6 to 7 Oe. In this region, as illustrated in FIG. 4, the resonant frequency shifts by about 650 Hz per Oe of field strength. Preferably, an adjacent high coercive magnetic biasing element 14 , shown in FIG. 2, provides the bias magnetic field.
Referring to FIG. 6, the quality factor (Q) is illustrated as a function of the external magnetic field strength. The Q is an indication of how lossy the resonator is. The higher the Q, the lower loss the resonator has, and the longer the ring-down time will be after the transmitter is turned-off. The resonator's Q decreases with the bias dc magnetic field until reaching a minimum at about 12 Oe.
Referring to FIG. 7, the frequency response of marker 2 with resonator 12 as described above is illustrated. The relative marker signal level on the vertical axis is plotted against swept frequency on the horizontal axis. In this embodiment, the resonant frequency is 58.2 kHz, the Q is 380. The anti-resonant frequency shown at 22 is due to the magneto-mechanical coupling. From above, we know that the resonant frequency shifts about 650 Hz per oersted of external magnetic field. The application of a low frequency alternating magnetic field shifts the resonant frequency, and along with the resonant excitation frequency, results in a fluctuation in peak marker response that is synchronous with the low frequency magnetic field. The marker response shows up as a modulation of the resonant or “carrier” frequency by the low frequency modulation magnetic field.
Referring to FIG. 8, the mixing response on a 58 kHz carrier frequency and a 200 Hz modulating signal is illustrated for a marker 2 made in accordance with the present invention. The field strength of the 58 kHz carrier is about 0.58 mOe, and the field strength of the 200 Hz modulation frequency is about 9.76 mOe. The resonant frequency 30 and the first sidebands 32 , resulting from the modulation are clearly visible, along with a second sideband 33 . The first sidebands 32 are +/−200 Hz away from the fundamental or resonant frequency 30 as expected. As described above, the resonator 12 is biased by a dc magnetic field of about 6 to 7 Oe. Referring back to FIG. 3, the resonator 12 is performing a modulation while operating in a linear magnetic response region indicated by 20 .
Referring to FIG. 9, the mixing response on a 58 kHz carrier frequency at 0.58 mOe field and a 200 Hz modulating signal is illustrated for a marker 2 made in accordance with the present invention. As in FIG. 8, the carrier frequency of 58 kHz is at a field level of 0.58 mOe. The 200 Hz modulation frequency is at a higher field level of 38.9 mOe. The resonant frequency 35 and the first sidebands 36 at +/−200 Hz from the fundamental or resonant frequency 35 , as well as the second sidebands 38 at +/−400 Hz from the resonant frequency 35 , are clearly visible with the higher field strength of the low frequency signal.
Referring to FIG. 10, the signal ratio of the fundamental frequency and its sideband components are illustrated as a function of the low frequency signal amplitude. The first sidebands are designated as 24 and 25 for left and right, or 200 Hz lower and 200 Hz higher than the fundamental frequency, respectively. The second sidebands are designated as 26 and 27 for left and right, or 400 Hz lower and 400 Hz higher than the fundamental frequency, respectively. By the slope of the curves it is apparent that the first sidebands, 24 and 25 , are 30 linearly proportional to the amplitude of the low frequency magnetic field. The secondary sidebands, 26 and 27 , are proportional to the square of the low frequency field strength. The response of the marker to the carrier frequency is linear, with an effective permeability of about 20,000.
Therefore, it is clear that the field strength of the low frequency signal determines the ratio between the fundamental and the sideband components. As the low frequency field increases, the first sideband goes up linearly with the field strength of the low frequency signal. The second sideband increases according to the square of the field strength of the low frequency signal. The level of the fundamental depends on the carrier frequency, so that as the low frequency magnetic field strength is increased, the ratio of the sidebands to the fundamental increased. The net energy in the fundamental and the sidebands is determined by the field strength of the carrier signal.
Referring to FIG. 11, the response of marker 2 with respect to the carrier frequency is illustrated. A significant gain in the fundamental component is evident at 40 when the excitation frequency matches the marker's resonant frequency. The response of the fundamental frequency has a maximum 40 at 58.2 kHz in this embodiment.
Referring to FIG. 12, the left first sideband 42 and right first sideband 44 response to the excitation frequency is illustrated. The sideband amplitudes show a significant gain around the marker resonance frequency, with the left first sideband 42 and the right first sideband 44 maximum peaks occurring at 58.0 kHz and 58.4 kHz, respectively.
Referring back to FIG. 1, the modulated sidebands generated by marker 2 , as illustrated and described hereinabove, are detectable by receiver 8 . Receiver 8 includes a sideband detector that processes modulated sideband signals, which can be implemented in conventional manner as known in the art. A plurality of modulating low frequency signals can be transmitted in separate zones to localize the position of a detected marker 2 .
Referring to FIG. 13, an alternate embodiment for an EAS system incorporating the present invention is illustrated. One or more resonant frequency transmitters 50 transmits a carrier frequency, which, for example, can be 58.2 kHz, into zones 52 , 53 and 54 . Three zones Z 1 , Z 2 , and Z 3 are illustrated, but any number of zones can be implemented in accordance with the present invention. Low frequency transmitters 56 , 58 , and 60 , transmit three different modulating frequencies, T 1 , T 2 , and T 3 , which for example can be 200 Hz, 250 Hz, and 300, Hz, respectively. One or more receivers 62 detect the sidebands generated by a marker 2 in any of the zones 52 , 53 or 54 , as described hereinabove. The detected sideband frequency T 1 , T 2 , or T 3 , such as 200 Hz, 250 Hz, or 300 Hz, will indicate which zone marker 2 was in when detected by receiver 62 .
The marker selected and described hereinabove as a preferred embodiment includes mixing capabilities depending upon various excitation conditions such as the modulation frequency and amplitude, the carrier frequency and amplitude, the de bias magnetic field level, and the Q factor. It is clear from the above that the marker carrier and modulation frequencies, the amplitude of the fundamental and sidebands, and the ratio of sideband amplitude to fundamental amplitude are all selectable parameters.
It is to be understood that variations and modifications of the present invention can be made without departing from the scope of the invention. It is also to be understood that the scope of the invention is not to be interpreted as limited to the specific embodiments disclosed herein, but only in accordance with the appended claims when read in light of the forgoing disclosure.
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An electronic article surveillance (EAS) system and method utilizing two transmitted signals to generate and detect a marker signal is provided. The first signal is set at or near the resonance of the marker so its energy can be transmitted and stored in the marker. The second signal is a low frequency magnetic field that changes the resonant frequency of the marker. Because the marker's resonant frequency is constantly varying in response to the low frequency magnetic field, the marker's response to the first transmitted signal also changes. As a result, the marker performs a modulation on the first transmitted signal. Detection of a sideband of the modulated signal indicates the presence of the marker within an interrogation zone formed by the two transmitted signals. Multiple interrogation zones can be implemented by transmitting multiple low frequency signals, one low frequency signal for each interrogation zone.
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[0001] This application is a Continuation-in-Part of U.S. application Ser. No. 11/066,099, having been filed May 23, 2005, which application is a Continuation-in-Part of U.S. application Ser. No. 10/347,489 (now U.S. Pat. No. 6,860,074); having been filed on Jan. 21, 2003, which in turn is a Continuation-in-Part of U.S. application Ser. No. 09/986,414, having been filed on Nov. 8, 2001, and U.S. application Ser No. 10/748,852, having been filed on Dec. 31, 2003, each of which is herein incorporated by reference in its entirety.
BACKGROUND
[0002] 1. Field of the Invention
[0003] The invention is a joint cover assembly that includes a molding, similar to a transition molding between two separate parts, such as a T-Molding, for covering a gap that may be formed between adjacent panels in a generally planar surface, such as between two adjacent flooring or wall or ceiling materials; or between a floor and a hard surface or carpet, or even a riser and a runner in a step (or a series of steps).
[0004] 2. Background of the Invention
[0005] Hard surface floors, such as wood or laminate flooring have become increasingly popular. As such, many different types of this flooring have been developed. Generally, this type of flooring is assembled by providing a plurality of similar panels. The differing types of panels that have developed, of course, may have differing depths and thicknesses. The same is true when a laminate floor (often referred to as a “floating floor”) abuts another hard surface, such as a resilient surface (such as vinyl), tile or another laminate surface, a ceramic surface, or other surface, e.g., natural wood flooring. Thus, when laminate panels having different thicknesses or different floor covering materials are placed adjacent to a laminate floor, transition moldings are often used to create a transition between the same.
[0006] Additionally, one may desire to install floor panels adjacent to an area with different types of material. For example, one may desire to have one type of flooring in a kitchen (e.g., solid wood, resilient flooring, laminate flooring or ceramic tile), and a different appearance in an adjacent living room (e.g., linoleum or carpeting), and an entirely different look in an adjacent bath. Therefore, it has become necessary to develop a type of molding or floorstrip that could be used as a transition from one type of flooring to another.
[0007] A problem is encountered, however, when flooring materials that are dissimilar in shape or texture are used. For example, when a hard floor is placed adjacent a carpet, problems are encountered with conventional edge moldings placed therebetween. Such problems include difficulty in covering the gap that may be formed between the floorings having different height, thickness or texture.
[0008] Moreover, for purposes of reducing cost, it is important to be able to have a molding that is versatile, having the ability to cover gaps between relatively coplanar surfaces, as well as surfaces of differing thicknesses.
[0009] It would also be of benefit to reduce the number of molding profiles that need to be kept in inventory by a seller or installer of laminate flooring. Thus, the invention also provides a method by which the number of moldings can be reduced while still providing all the functions necessary of different styles transition moldings.
SUMMARY OF THE INVENTION
[0010] The invention is a joint cover assembly for covering a gap between edges of adjacent floor elements, such as floor panels of laminate or wood, although it may also be used as a transition between a laminate panel and another type of flooring, e.g., carpet, linoleum, ceramic, wood, etc. The assembly typically includes a body having a foot positioned along a longitudinal axis, and a first arm extending generally perpendicularly from the foot. The assembly may include a second arm also extending generally perpendicular from the foot. Securing elements are provided to secure attachments to the at least one of the first and second arms. These securing elements may take the form of adhesive. The securing elements may also be in the form of a tab, which may be provided on at least one of the first or second arms, displaced from, or adjacent, the foot, extending generally perpendicularly from the arm.
[0011] The outward-facing surface of the assembly may be formed as a single, unitary, monolithic surface that covers both the first and second arms. This outward-facing surface may be treated, for example, with a laminate or a paper, such as a decor, impregnated with a resin, in order to increase its aesthetic value, or blend, to match or contrast with the panels. Preferably, the outward facing surface has incorporated therein a material to increase its abrasion resistance, such as hard particles of silica, alumina, diamond, silicon nitride, aluminum oxide, silicon carbide and similar hard particles, preferably having a Moh's hardness of at least approximately 6. This outward-facing surface may also be covered with other types of coverings, such as foils (such as paper or thermoplastic foils), paints or a variety of other decorative elements.
[0012] The assembly is preferably provided with a securing means to prevent the assembly from moving once assembled. In one embodiment, the securing means is a clamp, designed to grab the foot. Preferably, the clamp includes a groove into which the foot is inserted. In a preferred embodiment, the clamp or rail may joined directly to a subsurface below the floor element, such as a subfloor, by any conventional means, such as a nail, screw or adhesive.
[0013] A shim may also be placed between the foot and the subfloor. In one embodiment, the shim may be positioned on the underside of the clamp; however, if a clamp is not used, the shim may be positioned between the foot and the subfloor. The shim may be adhered to either the foot or subfloor using an adhesive or a conventional fastener, e.g., nail or screw.
[0014] The assembly may also include a leveling block or reducer positioned between at least one of the first and second arms and the adjacent floor. The leveling block generally has an upper surface that engages the arm, and a bottom surface that abuts against the adjacent floor. In a preferred embodiment, the leveling block has a channel or groove formed in an upper surface, configured to receive the tab on the arm. The particular size of leveling block is often chosen to conform essentially to the difference in thicknesses between the first and second panels. The exposed surfaces of the leveling block are typically formed from a variety of materials, such as a carpet, laminate flooring, ceramic or wood tile, linoleum, turf, paper, natural wood or veneer, vinyl, wood, ceramic or composite finish, or any type of covering, while the interior of the leveling block is generally formed from wood, fiberboard, such as high density fiberboard (HDF) or medium density fiberboard (MDF), plastics, or other structural material, such as metals or composites, at least over a portion of the surface thereof may be covered with a foil, a plastic, a paper, a décor or a laminate to match or contrast with the first and second arms. The leveling block additionally facilitates the use of floor coverings having varying thicknesses when covering a subfloor. The leveling block helps the molding not only cover the gap, but provide a smoother transition from one surface to another.
[0015] Alternatively, the tab may be positioned to slidingly engage the edge of a panel when no leveling block is used. A lip may additionally be provided and positioned on the tab in order to slidingly engage a protuberance, adjacent an upper edge of the clamp, in order to retain the assembly in its installed position.
[0016] The tab is preferably shaped as to provide forces to maintain the assembly in the installed position. Thus, typically the tab may be frustum-shaped, (e.g., dove-tailed) with its narrow edge proximate the arm and the wider edge furthest from the arm. Additionally, the tab may be lobe shaped, having a bulbous end distal from the arm. In another embodiment, only one side of the tab need be tapered (e.g., half dove-tailed). Of course, any suitable shape is sufficient, as long as the engagement of the tab and groove can provide enough resistive forces to hinder removal of the installed assembly. By forming a suitable groove in the leveling block, the tab can help to secure the assembly in place. Typically, a corresponding groove, having a similar shape as the tab is included in the leveling block or reducer, e.g., having its wider base distal the arm and its narrower opening proximate the arm. It is to be understood by those skilled in the art that although the description throughout this specification is that the position of the tab is on the at least one of the first and second arms, and the groove is on the attachment, e.g., leveling block, the relative position of the tab and groove can be reversed.
[0017] The assembly may additionally be used to cover gaps between tongue-and-groove type panels, such as glueless laminate floor panels. In addition to the uses mentioned above, the tab may also be designed to mate with a corresponding channel in the panel, the edge of one of the flooring elements, or may actually fit within a grooved edge. In order to better accommodate this type of gap, a second tab may be positioned to depend from the second panel engaging surface.
[0018] An adhesive, such as a glue, a microballoon adhesive, contact adhesive, or chemically activated adhesive including a water-activated adhesive, may be also positioned on the tab, in the groove, on the foot, and on at least one of the arms. Of course, such an adhesive is not necessary, but may enhance or supplement the fit of the assembly over the gap between, the floor elements. Additionally, the adhesive may assist in creating a more air-tight or moisture-tight joint.
[0019] The assembly may be used in other non-coplanar areas, such as the edge between a wall and a floor, or even on stairs. For example, the assembly may include the first and second arms, and foot as described above, but instead of transitioning between two floor elements placed in the same plane, may form the joint between the horizontal and vertical surfaces of a single stair element.
[0020] The inventive assembly may be used for positioning between adjacent tongue-and-groove panels; in this regard, the assembly functions as a transition molding, which provides a cover for edges of dissimilar surfaces. For example, when installing floors in a home, the assembly could be used to provide an edge between a hallway and a bedroom, between a kitchen and living or bathroom, or any areas where distinct flooring is desired. Additionally, the assembly may be incorporated into differing types of flooring, such as wood, tile, linoleum, carpet, or turf.
[0021] The invention also is drawn to an inventive method for covering a gap between adjacent panels of a generally planar surface. The method includes multiple steps, including, inter alia, placing the foot in the gap, pressing the respective arms in contact with the respective floor elements, and configuring at least one of the tab and the foot to cooperate to retain the assembly in the gap after the assembly has been installed.
[0022] Other objects, features and advantages of the present invention will become apparent from the following detailed description. It should be understood, however, that the detailed description and the specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] FIG. 1 is an exploded view of an embodiment of the joint cover assembly in accordance with the invention;
[0024] FIGS. 1A and 1B are alternate embodiments for the molding of the invention;
[0025] FIG. 2 is a perspective view of a second embodiment of the joint cover assembly in accordance with the invention;
[0026] FIGS. 3 and 3A are comparative perspective views of embodiments of the leveling block;
[0027] FIG. 4 is perspective view of an additional embodiment of the joint cover assembly in accordance with the invention;
[0028] FIGS. 5 and 5A are comparative perspective views of embodiments of the leveling block;
[0029] FIGS. 6-16 show comparative cross-sectional views of various embodiments of the molding portion of the joint cover assembly;
[0030] FIG. 17 depicts an embodiment of the assembly of the invention for use with stairs;
[0031] FIG. 18 shows a second embodiment of the assembly for use with stairs;
[0032] FIG. 19 is a side view of a generic element, which may be broken into the components of the invention; and
[0033] FIGS. 20-81 are various modifications of molding of the invention.
[0034] FIGS. 82-111 depict additional modifications of the molding the invention.
[0035] FIGS. 112-119 show even further modifications of the molding of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0036] FIG. 1 shows an exploded view of the various parts of the inventive joint cover assembly 10 . The assembly 10 includes a T-shaped molding 11 , having a foot 16 formed so that it can fit in a gap 20 between adjacent floor elements 24 , 25 . FIG. 1 demonstrates a typical use, in which the gap 20 is formed adjacent an edge 27 of a floor element 24 . Although FIG. 1 depicts all of the floor elements 24 to be conventional tongue-and-groove type floor panels (having a groove 27 positioned adjacent to the gap 20 ), this is merely one of any number of embodiments. For example, floor elements 24 , 25 need not be the same type of floor element. Specifically, the floor elements 24 can be any type of flooring designed to be used as a floor or placed over a subfloor 22 , e.g., tile, linoleum, laminate flooring, concrete slab, parquet, vinyl, turf, composite or hardwood. As is known, laminate floors are not attached to the subfloor 22 , but are considered “floating floors.” Although the figures illustrate particular locations for features such as the tab 18 and channel 42 , it is within the scope of the invention to reverse the relative locations of such features.
[0037] The molding 11 is provided with a first arm 12 and a second arm 14 extending in a single plane generally perpendicular to the foot 16 . Preferably, the foot 16 , first arm 12 , and the second arm 14 form a general T-shape, with the arms 12 and 14 forming the upper structure and the foot 16 forming the lower structure. Although the foot 16 is shown as being positioned at a central axis of the molding 11 , such is only a preferred embodiment. In other words, it is within the scope of the invention to vary the position of the foot 16 “off center” with respect to the first and second arms 12 , 14 . For example, the foot 16 may be placed at the midpoint, or anywhere in between, as is depicted, for example, in FIGS. 82-99 .
[0038] As shown in FIGS. 82-111 , a molding 1110 need not form a true right angle with its foot 1116 . For example, the transition from a respective outstretched arm 1112 or 1114 to a foot 1116 may be achieved by one or more rounded sections, or a plurality of straight sections. While the figures only illustrate an angle of other than 90° between arm 1114 and foot 1116 , it is within the scope of this invention to provide the transition between arm 1112 and foot 1116 , or both transitions with such an angle. Typically, these transitions are formed by undercutting the desired angle, as will be described in greater detail below.
[0039] The molding 11 , as well as any of the other components used in the invention, may be formed of any suitable, sturdy material, such as wood, polymer, fiberboard, plywood, or even a wood/polymer composite, such as stranboard. Due to the growing popularity of wood and laminate flooring and wood wall paneling, however, a natural or simulated wood-grain appearance may be provided as the outward facing surface 34 of the molding 11 . The outward facing surface 34 may be a conventional laminate, such as a high pressure laminate (HPL), direct laminate (DL) or a post-formed laminate (as described in U.S. application Ser. No. 08/817,391, herein incorporated by reference in its entirety); a foil; a print, such as a photograph or a digitally generated image; or a liquid coating including, for example, aluminum oxide. Thus, in the event natural wood or wood veneer is not selected as the material, the appearance of wood may be simulated by coating the outer surface 34 with a laminate having a decor sheet that simulates wood. Alternatively, the decor can simulate marble, ceramic, terrazzo, stone, brick, inlays, or even fantasy patterns. Preferably, the outward facing surface 34 extends completely across the upper face of the molding, and optionally under surface 36 and 38 of arms 12 and 14 , respectively.
[0040] The core structure of components of the invention, including the center of the molding 11 , that is in contact with the outward facing surface 34 is formed from a core material. Typical core materials include wood based products, such as high density fiberboard (HDF), medium density fiberboard (MDF), particleboard, strandboard, plywood, and solid wood; polymer-based products, such as polyvinyl chloride (PVC), thermoplastics or thermosetting plastics or mixtures of plastic and other products, including reinforcements; and metals, such as aluminum stainless steel, brass, aluminum or copper. The various components of the invention are preferably constructed in accordance with the methods disclosed by U.S. application Ser. No. 08/817,391, as well as U.S. application Ser. No. 10/319,820, filed Dec. 16, 2002, each of which is herein incorporated by reference in its entirety.
[0041] The resulting products typically have durability rating. As defined by the European Producers of Laminate Flooring; such products can have a durability rating of anywhere from AC1 to AC5. Preferably, the products of this invention have a rating of either AC3 or AC5.
[0042] A securing element, such as a metal clamp, track or rail 26 , may be coupled to the subfloor 22 within the gap 20 formed between the two floor elements 24 . The clamp may be coupled to the subfloor 22 by fasteners, such as screws or any conventional coupling method, such as nails or glue. The clamp 26 and the foot 16 are preferably cooperatively formed so that the foot 16 can slide within the clamp 26 without being removed. For example, the clamp 26 may be provided with in-turned ends 30 designed to grab the outer surface of the foot 16 to resist separation in a vertical direction. Typically, the foot 16 has a dove-tail, shape, having the shorter parallel edge joined to the arms 12 and 14 ; and the clamp 26 is a channeled element having a corresponding shape as to mate with the foot 16 and hold it in place. Additionally, the securing element may take the form of an inverted T-element 50 ( FIG. 1A ), configured to mate with a corresponding groove 52 in an end of foot 16 , such that friction between the T-element 50 and the groove 52 secures the molding 11 in place, or, in the alternative, the end of the foot 16 may be provided with a narrowed section, designed to mate with a groove in the securing element. Finally, each of the T-element 50 , mating section of the foot 16 and/or various grooves, may be provided with notched or barbed edges 55 to simultaneously assist in mating and resist disassembly ( FIG. 1B ). However, in an alternative embodiment, the securing element can be eliminated because the molding 11 can be affixed to one of the floor elements 24 , 25 , by, for example, an adhesive. Preferably, however, the molding 11 is not secured to both floor elements 24 , 25 , as to permit a degree of relative movement, or floating, between the floor elements 24 , 25 .
[0043] The clamp 26 may additionally be formed of a sturdy, yet pliable material that will outwardly deform as the foot 16 is inserted, but will retain the foot 16 therein. Such materials include, but are not limited to, plastic, wood/polymer composites, wood, and polymers. The clamp 26 may additionally engage recesses in, for example, sides of the foot 16 .
[0044] A tab 18 is shown as extending downwardly from the first arm 12 . As shown in FIG. 1 , the tab 18 extends downward, or away from an outward facing surface 34 of the molding, and runs generally parallel to the foot 16 . As shown in FIG. 1 , the tab 18 may also be in the shape of a dove-tail with a shorter edge adjacent to the first arm 12 ; however, other suitable shapes are possible. The shape of the outwardly facing surface 34 of the molding 11 is shown as being convex in some of the Figures (e.g., FIGS. 1A , 1 B and 7 ), and substantially planar in others (e.g., FIGS. 1 , 2 , 4 , and 6 ). When the outwardly facing surface 34 is substantially planar, the edges of the molding 11 may either be upright or at an angle, typically angling away from the foot 16 . However, the relative positions of the tongue/groove may also be reversed.
[0045] The assembly may further include a leveling block 40 otherwise known in the art as reducers. When flooring elements 24 and 25 are of differing heights, the leveling block 40 is positioned between either the first arm 12 or the second arm 14 and the subfloor 22 . Preferably, the size of the leveling block 40 is selected to correspond essentially to the difference in heights of the two flooring elements 24 and 25 . However, if an adjustable pad 1120 (as described below) is used, the particular height of the reducer is not particularly important. For example, if one flooring element 24 is a ceramic tile, having a thickness, of 2″ and the second flooring element 25 is vinyl, having a thickness of ¼″, the leveling block 40 would typically have a thickness of 1¾″ to bridge the difference and be placed between arm 12 and the other flooring element 25 . Without the leveling block 40 , a significant space would exist between the second flooring element 25 and the molding 11 , allowing for moisture and dirt to accumulate. While the difference in heights of the flooring elements 24 , 25 is generally caused by a difference in thickness between the two flooring elements 24 , 25 , the present invention may also be used to “flatten out” an uneven subfloor 22 . In addition, a shim may be placed under the track to adjust for differences in floor thickness. In a preferred embodiment, the leveling block is provided with a channel 42 designed to receive the tab 18 .
[0046] The width of the foot 16 , 1116 may be different, depending upon the particular application. For example, when a reversible molding element 1250 is used, it is preferred that the width of the foot 16 , 1116 be narrower to accommodate the proximal portions of the molding element. Typically, the clamp 26 , 1126 is also adjusted to accommodate the appropriate foot 16 , 1116 .
[0047] Even though the assembly 10 may function without any type of glue or adhesive, an alternate embodiment includes the placement of adhesive 31 on the molding 11 . The adhesive may be placed on molding 11 at the factory (for example, pre-glued). Alternatively, the glue may be applied while the floor elements 24 , 25 are being assembled. As shown in FIG. 6 , the adhesive 31 may be provided as a strip-type adhesive, but any type of adhesive, such as glue, chemical or chemically-activated adhesive, water-activated adhesive, contact cements, microballoon or macroballoon encapsulated adhesive may be used. Additionally, while the embodiment in FIG. 6 shows a single adhesive strip 31 attached to the arm 12 , the adhesive 31 may be attached to the tab 18 , foot 16 , and/or any location where two pieces of the assembly are joined. In some embodiments, the adhesive may be used as an alternative to tab 18 and groove 42 . Preferably, adhesive 31 is only applied to one of the arms 12 , 14 in order to allow or accommodate some slight relative movement that may occur during changes of temperature, for example. This relative movement is known in the flooring art as “float”. Allowing float may also eliminate unneeded material stresses as well, thereby reducing warping or deterioration of the material surface. Typical adhesives used in the invention include a fresh adhesive, such as PERGO GLUE (available from Perstorp AB of Perstorp, Sweden), water activated dry glue, dry glue (needing no activation) or an adhesive strip with a peel off protector of paper.
[0048] FIG. 2 shows a typical embodiment of the assembly 10 in an installed condition, wherein the floor elements 24 and 25 are of differing thicknesses (H and H′ respectively). Of course, the element 24 may be of any type of covering, such as carpet, turf, tile, linoleum or the like. As shown in FIG. 3 , the leveling block 40 typically includes a substantially flat bottom 46 , and a top 45 having a groove 42 , and an inner surface 44 . The top 45 of the leveling block 40 is designed to firmly abut the under surface 36 of the first arm 12 , while the bottom 46 abuts floor element 25 . Typically, the groove 42 is shaped as to firmly hold the tab 18 . By having a corresponding shape, for example, the groove 42 can have a dove-tail shape, where both lateral sides diverge from the upper surfaces or a “half-dove tail,” where only one of the two sides is so configured. The inner surface 44 of the leveling block 40 need not abut the foot, as generally, a small amount of clearance is provided between the clamp 26 or foot 16 and the inner surface 44 of the leveling block. However, the inner surface 44 may be configured to contact either of the clamp 26 or foot 16 . The tab 18 may also be of a shape different than groove 42 , e.g., a wedged-shaped tab fitting within a straight-walled groove. In other embodiments, friction will be sufficient to maintain the position of the tab and groove elements.
[0049] The leveling block 40 may be made of a composite, pliable material that is also resilient. For example, the tab 18 may be formed to be slightly larger than the opening of the channel 42 , thereby forcing the channel 42 to outwardly deform in order to accommodate the tab 18 , and therefore snap-fit together.
[0050] As shown in FIG. 3 , the outer surface 47 of the leveling block 40 is generally treated to match or blend with the outer surface 34 of the molding or the floor element 24 , 25 in order to improve aesthetics.
[0051] FIG. 3A shows an alternate embodiment of a leveling block 40 ′. An outer surface 47 ′ of this embodiment is configured generally perpendicular to an upper surface 44 ′ and a lower surface 46 ′ of the leveling block 40 ′. This alternate configuration of the outer surface 47 ′ not only provides a different appearance, it also has been shown to be preferred when softer surfaces, such as carpet or turf, are positioned beneath the lower surface 46 ′ of the leveling block 40 ′.
[0052] FIG. 4 shows yet another alternate embodiment of the leveling block 140 . The leveling block 140 includes a bottom 146 , and a top 145 and an inner surface 144 . The top 145 of the leveling block 140 is designed to firmly abut the under surface 36 of the first arm 12 , while the bottom 146 abuts floor element 25 . This leveling block 140 is positioned between a first arm 112 of the molding 111 and the flooring element 125 . In this embodiment of the assembly 110 , the tab 118 engages the inner surface 144 of the leveling block 140 .
[0053] FIG. 5 shows an embodiment of a leveling block 140 that may be used in the assembly shown in FIG. 4 . Specifically, the leveling block 140 in FIG. 5 has a solid, uninterrupted upper surface 145 , without the need for a channel because the tab ( 118 , as in FIG. 4 ) will engage the inner surface 144 of the leveling block instead of the top surface 145 . In such an embodiment, the tab 118 may also be adjacent the foot. In some embodiments, the use of adhesive will reinforce the positioning of the leveling block 140 relative to tab 118 .
[0054] FIG. 5A shows an additional shape of a leveling block 140 ′ that can be incorporated into the assembly shown in FIG. 4 . Leveling block 140 ′ has a front surface 146 ′ that will be generally perpendicular to a floor 122 (as shown in FIG. 4 ) when the leveling block 140 ′ is installed. This perpendicular configuration of the front surface 147 ′ not only provides a different appearance, it has also been found to be preferred with softer surfaces, such as carpet or turf. FIG. 6 shows an underside view of the molding 11 . In particular, the first under surface 36 of the first arm 12 , and the second under surface 38 of the second arm 14 are shown. In one embodiment, under surface 36 is provided with the adhesive 31 positioned to adhere to a surface of a floor element 24 , 25 or leveling block 40 , 40 ′, 140 , 140 ′.
[0055] FIGS. 7-15 show various cross-sectional views of the molding 11 . These figures show comparative configurations for the arms 12 , 14 , the tab 18 , and the shape of molding 11 .
[0056] In FIG. 7 , the tab 18 is selected to be an outward-facing hook having a barb facing away from the foot 16 , while the upper surface of the molding has a convex curvature. This particular selection for the tab 18 may be used to engage an edge or groove of an adjacent floor element 24 , 25 , or, in the alternative, an adjacent leveling block 40 . Additionally, a shim 48 may be positioned between the foot 16 and the subfloor 22 . The shim 48 is generally formed of a pliable and flexible, yet durable, material, such as a polymer, preferably a polymer exhibiting electrometric properties. The shim 48 may be used in place of, or in combination with, clamp 26 . Preferably, the shim 48 is sized in accordance with the size of the clamp 26 , 1126 .
[0057] FIGS. 8-15 show cross-sections of other shapes for the molding 11 . The configurations of the moldings are very similar, except for the shape of the tab 18 . The differing tabs have been assigned decimal numbers beginning with 18 , for clarity purposes. A tab 18 . 1 ( FIG. 8 ) is a bulbous shape, having its rounded end furthest from the arm 12 . tab 18 . 2 ( FIG. 9 ) is provided with a hook-shape with a point facing the foot 16 . In the embodiment shown in FIG. 10 , a tab 18 . 3 is in the shape of a dove-tail, similar to the shape of the tab 18 shown in FIG. 2 . The tab 18 may additionally be configured to have a substantially rectangular cross section with two opposite rounded off corners, as shown in FIGS. 82-111 , or any of the other shapes described herein, with one or more of the corners/ends being rounded.
[0058] The purpose of the various-shaped tabs ( 18 - 18 . 8 ) is multi-fold. Primarily, the tab 18 serves to engage the channel 42 of the leveling block 40 , which is used when covering of differing thickness is used. Alternatively, the respective tab ( 18 - 18 . 8 ) may engage an edge of a panel, carpet, turf, or other type of floor covering. As shown herein, the respective tab ( 18 - 18 . 8 ) may even be configured to engage a leveling block it is additionally considered within the scope of the invention to eliminate the tab. In such an embodiment, preferably, the molding 11 includes an adhesive on the under surface 36 , 38 of one of the arms 12 , 14 .
[0059] With respect to FIG. 16 , the invention may also be used when the floor elements are not co-planar. For example, one embodiment includes a stair nose attachment 210 that can be attached to the same molding 11 , as described above. As used herein, a stair nose attachment is a component capable of mating with the molding 11 so as to conceal, protect or otherwise cover a joint forming a single stair. Typically, the molding 11 is provided atop the first floor element 24 on the horizontal, or run 220 of the stair, such that the stair nose attachment 210 bridges the joint between the first floor element 24 and the second floor element 25 , forming the vertical section of the stair, or rise 230 . As a result, the invention can be used to cover and protect joints between flooring elements on stairs. While in a preferred embodiment, the floor elements covering the rise 220 and run 230 are the same type of flooring material, the flooring elements need not be of the same construction or type of materials.
[0060] The stair nose attachment 210 may include a tab receiving groove 212 , permitting connection of the stair nose attachment 210 to the molding 11 . Because the tab receiving groove 212 in the stair nose attachment 210 is preferably shaped according to the shape of the tab 18 of the molding 11 , the stair nose attachment 210 may be attached to the molding 11 by, for example, snapping or sliding.
[0061] However, in other embodiments, the tab on the under surface 36 is eliminated. While the tabs and corresponding grooves may be eliminated, it is nevertheless considered within the scope of the invention to utilize an adhesive, as described herein. Alternatively, the stair nose attachment 210 may include a tab 218 to mate with a corresponding groove 219 on the foot 16 of the molding 11 ( FIG. 17 ), or vice-versa.
[0062] By allowing an end user to purchase the generic element 300 instead of separate components, the retailers and/or distributors may accordingly reduce their inventory requirements. For example, typically over one-hundred different design patterns for the outwardly facing surface 34 of the molding 11 (as well as for the leveling block 40 and stair nose attachment 210 ) are produced. By allowing for the inventory to include only the generic elements of the invention, the total number of components retained can be reduced from three per design to one per design. Similarly, the installer only need purchase the generic elements 300 , rather than three individual components. Thus, both retailers and installers may profit from having less storage and/or retail bays to service the same types of accessories as prior to the invention.
[0063] FIGS. 20-53 depict alternate embodiments for the leveling block (or other pieces) and the molding 11 .
[0064] FIG. 20 shows a general representation of the molding with a track 101 and shim 102 , below the molding 11 . Preferably, the track 101 is metal, and the shim 102 is plastic. However, it is within the scope of the invention to form either of these pieces out of either material. Additionally, other materials may be used, such as materials which flex, but return to their original configuration when pressure is applied and then released. In one embodiment, a track 101 , formed of metal, is fastened to a subfloor with screws. For thicker laminate flooring, the shim 102 may be snapped to the underside of the track before it is fastened to the subfloor. Use of the shim 102 offers a height adjustment for multiple thicknesses of laminate, or other flooring. Thus, where the height of a surface below the molding 11 requires the molding to be raised, the shim 102 can be used to provide the necessary spacing. However, it must be noted that, although FIG. 20 shows the shim 102 being used, such is an optional element, as the shim 102 may be used with each of the shapes and designs of moldings 11 disclosed herein, or similarly, eliminated from each embodiment, as required by the particular circumstances.
[0065] As shown in FIGS. 90-99 and 102 - 111 , the shim 102 may be in the form of a pad 1102 , which may be provided with one or more upturned ends 1102 a and 1102 b . Preferably, the upturned ends 1102 a and 1102 b of the pad 1102 are sized and shaped to receive foot 1116 if desired. Thus, in a number of embodiments, shown for example in FIGS. 102-111 , the foot 1116 is positioned in the pad 1102 , such that the upturned ends 1102 a and 1102 b grip or grasp the clamp 1126 . If the upturned ends 1102 a and 1102 b , or even the entire pad, 1102 are formed from a resilient material, such as a plastic or elastomer or certain types of metal, the gripping force provided can be greater. However, the pad 1102 and the parts thereof can be constructed of any material. The pad 1102 may additionally be affixed to a clamp 1126 with a fastener, such as a screw or nail, and/or an adhesive, such as a glue or adhesive tape. In the embodiment shown in FIGS. 98 , 99 , 110 and 111 , the pad 1102 is inverted, such that upturned ends 1102 a and 1102 b are directed toward the subfloor and away from the clamp 1126 in order to provide the clamp 1126 with additional height. This allows a single pad 1102 to accommodate a variety of height requirements. Moreover, if needed, it is possible to cut off a terminal section of the upturned ends 1102 a and 1102 b to accommodate an unlimited number of additional heights. The size and depth of the pad 1102 is not limited by the present invention and is typically any height, from 1 mm up to 4 mm, with additional height being provided when the pad 1102 is inverted. Typically, the pad 1120 , just like the shim 102 , is sized in accordance with the clamp 26 , 1126 .
[0066] The size of the clamp 1126 is not particularly limited by the present invention. Typical clamp 1126 heights can be any dimension, preferably from 6-10 mm, most preferably 6.55 or 6.8 mm.
[0067] The embodiment of FIG. 21 has a leg of the molding 11 extended. Herein, there is a choice of height adjusting shims, which, in addition to the snap-on shim 102 , may additionally include a second shim 103 , formed of any material, such as wood, plastic, fiberboard, stone, metal, etc., that can be attached via any method to either the molding or the subsurface, such as with an adhesive, or screw. Typically, the extended leg of the T-molding is fastened to a subfloor with a silicone sealant, acting as an adhesive. Such a construction permits easy and quick installation, especially avoiding the need to drill holes and insert plugs for screws when installing over a concrete subfloor. The shim 102 can be attached to the underside of the extended leg of the T-molding to provide the appropriate height adjustment.
[0068] FIGS. 20 and 21 additionally represent the double and reversed tongue-and-groove configuration that functions to fasten a foot, hard surface reducer or carpet/end molding to the T-molding. In this configuration the tongue that extends from the underside of the T-molding is placed so that it falls within the expansion space of the installed flooring transition. This configuration does not require the removal of this tongue in order to install the T-molding part as a T-molding only. Should the laminate floor expand, the pressure will be sufficient to shear off this tongue on the underside of the molding, and the floor can move freely as if there were no extended tongue present in the expansion space.
[0069] Preferably, the shim 102 is a metal or plastic structure, having a pair of grabbing flanges 102 a for the purpose of clamping onto, for example, the track 101 . The grabbing flanges 102 a typically form an acute angle with respect to the remainder of the shim 102 , such that when the molding 11 is inserted into the shim 102 , the grabbing flanges 102 a are forced outward, and the grabbing flanges 102 a function to hold the molding 11 in place.
[0070] In a preferred embodiment, the molding 11 and a second member, such as a reducer, leveling block, stair nose, or any other molding attachment, are joined by one or more tongue-and-groove joints. For example, the second member can be provided with a tongue and the molding 11 is provided with a matching groove. As shown in FIGS. 25 and 26 , the tongue, which may be located on the second member, may be shaped as a dove-tail or a “half dove-tail,” wherein only one of the two sides defines an angle other than ninety degrees. Such a tongue may extend over any portion of the mating surface, such as small amount ( FIG. 25 ), approximately half ( FIG. 26 ), or even substantially the entire mating surface.
[0071] Typically, the tongue-and-groove are not simply rectangular in shape, but are provided with elements which tend to hold the pieces together. For example, as shown in FIGS. 20 , 21 , 25 , 28 , and 29 , the tongue may have, on at least one side, a tapered surface, resembling a dovetail, such that the pieces cannot simply dissociate without manipulation.
[0072] In the embodiments of FIGS. 20 and 21 , the reducer has on its mating surface, one tongue and one groove, while the molding 11 has the matching groove and tongue. In FIG. 21 a , the extended leg of the T-molding allows the T to be adhered to the sub-floor with construction adhesive or tapes or other adhesives. A shim can be placed on the bottom of the extended leg of the T-molding to raise the height, either a snap-on type of shim or a simple rectangular piece of material which can be adhered onto the bottom of the foot and then the assembly is adhered to the floor.
[0073] FIGS. 22 through 27 can represent either installation method, with a track or with an extended leg on the T-molding for, T-molding, hard surface reducer, carpet/end molding and stair nosing.
[0074] In the embodiments of FIGS. 22 and 23 , the pieces are provided with a horizontal flange 111 and the molding 11 has a similarly shaped groove. In FIG. 22 , the groove is not provided with any locking elements, while in FIG. 23 , the groove is provided with a locking flange 121 , which joins with a locking groove 112 on the second member to hold the pieces together. Although not specifically shown, it is within the scope of the invention to swap the location of the tongue/groove, such that the tongue is on the molding 11 , and the groove is positioned on the second member. Similarly, there may be any number of matching tongues/grooves, and each piece may have any combination of tongues and grooves. Similarly, as shown in FIG. 27 , the tongue and groove need not be positioned adjacent to the underside of one of the arms of the molding 11 , and a gap 114 may be provided in the second member to allow for greater movement between the second member and the first member without permitting dissociation. This gap may be a break-away feature.
[0075] In FIG. 22 , a recess lateral slot is present on the underside of the T-molding, as well as a groove in the leg of the T-molding. The recessed slot and raised platform of the top of each foot hinders lateral movement of the foot and the tongue and groove stabilize the foot against the top of the T-molding.
[0076] In FIG. 23 , there is a tongue and groove with a snap-fit ridge or tab at the end of the groove or in the tongue of the leg of the T-molding. There is also shown a corresponding groove in the underside of the tongue of each foot that snaps into the tab.
[0077] In the embodiment of FIG. 24 , the locking element 110 is a downwardly facing flange, sized and shaped to mate with the locking groove 112 on the second member. When the pieces are connected, the locking element 110 and locking groove 112 function to resist separation of the pieces in a horizontal direction. Although not shown, the locking element 110 and locking groove 112 , as shown in FIG. 24 , may be combined with any of the structures as shown in any of the other embodiments disclosed herein in order to assist in maintaining a secure connection between the elements.
[0078] In one embodiment, the extension 114 is affixed to the subfloor, by a means for securing. The securing means may be, for example, a mechanical fastener or a chemical fastener through, for example, boss 134 . As used herein, a mechanical fastener is any device which joins the elements with, e.g., pressure, and includes, but is not limited to, a nail, screw, staple, claw, clamp, barb, cant hook, clapper, crook, fang, grapnel, grappler, hook, manus, nipper, paw, pincer, retractile, spur, talon, tentacle, unguis, ungula, brad, point, push pin, and tack. Additionally, a chemical fastener is a component, such as a sealant or adhesive, and includes tapes, glues and epoxies. This extension 114 may also attach to the track.
[0079] The embodiments shown in FIGS. 28-35 each have an extension 120 of the second member which extends below the foot of the molding. In such embodiments, typically, the second member is a stair molding and is secured to the subfloor. The T-molding is then attached to the second member, as the T-molding does not contact the subfloor. However, it is considered within the scope of the invention to additionally provide an extension bracket (not shown) for securing the T-molding to the subfloor. As shown in FIGS. 28 , 29 and 35 , the second member may include a recess 124 into which the foot of the T-molding is inserted, or in the alternative, a depression 126 ( FIGS. 30 , 33 and 34 ).
[0080] Additionally, the second member may have a wedge 128 ( FIGS. 31 and 32 ) to secure the T-molding in place. The foot of the T-molding may either be angled into position to bypass the uppermost section of the wedge 128 , or the wedge may be formed such that it deflects under pressure and snaps back after the foot of the T-molding is properly positioned. Again, the embodiments of FIGS. 28-35 may be combined with one or more of the tongue and groove configurations as shown or described in connection with FIGS. 20-27 .
[0081] The second member, shown as a stair nosing, in FIGS. 28-35 may be installed using construction adhesives, specialized tapes (such as simple double-sided tapes), silicone or other sealants (such as epoxies or glues) or mechanical fasteners (such as screws or nails).
[0082] The embodiments of FIGS. 36-42 can be installed using a track 101 , similar to the embodiments shown in FIGS. 20-27 . In particular, either one or both of the T-molding and second member (shown as a stair nose) may be secured with the track 101 . The members can also be fastened to the track 101 after a construction adhesive or sealant/adhesive has been applied into the track and/or additional mechanical fasteners may be used to assist in fixing the second member to the subfloor (or tread, as necessary).
[0083] FIG. 43 demonstrates an extended face for a stair nose. Therein, the extended face is sufficient in breadth to cover the edge of common stair treads, thus eliminating the need to place a separate piece of flooring on the edge of stair treads or to cover the edge of a subfloor when stepping down from a floating floor installation to a lower level floor. However, stair noses may also be installed using the method described in connection with FIG. 21 , above, without the need of a track 101 , when the T-molding has an extended leg.
[0084] The embodiments of FIGS. 44-53 allow installation of the multipurpose flooring transition using only adhesives, tapes or sealants, as no track 101 is required. The additional surface area beneath the transition is increased adding additional adhesion area for strength in bonding the transition to the subfloor. This installation method also avoids the need for a track, screws and/or plugs (although they are certainly not prohibited), and additionally allows for faster installation over subfloors formed from, for example, wood based products or concrete.
[0085] FIGS. 44 and 45 show two assembled members held together with glue before fastening to the subfloor. Such members may also be installed by other methods described herein.
[0086] FIGS. 46-49 depict two members joined together with a snap-fit, such that no glue is necessary. Such members may also be installed by another method described herein. Although FIGS. 46-49 show a particular location for various snap-fitting elements, i.e., tongue and groove, it is certainly within the scope of this invention to increase the size, shape, location and number of the tongues and grooves as necessary. For example, FIG. 30 depicts one groove on either-side of the foot of the T-molding and corresponding tongues on the second member. However, additional tongues/grooves may be located on the bottom of the foot or even on the underside of the arm. Additionally, the second member may include both tongues and grooves, combining the features illustrated in FIGS. 46 and 47 with FIGS. 48 and 49 .
[0087] FIG. 50 represents a shim, which can be made from waste cuttings of the core material during the manufacture of the transition. This shim may be used to elevate the foot of the assembly to accommodate a thicker flooring material.
[0088] FIG. 51 shows an additional embodiment wherein the second member is a stair molding. The pieces, i.e., the T-molding and the stair molding, can be held together with glue before fastening to the subfloor, or by any other installation method described herein.
[0089] In FIG. 52 , an additional T-molding is shown that can snap-fit, i.e., without the need for glue, and FIG. 53 shows a corresponding track or structure to be incorporated into a second member. Specifically, the second member piece of FIG. 53 includes a plurality of alternating tongues and grooves, such that the foot of the T-molding, also having alternating tongues and grooves, form a snap action that functions to hold the T-molding firmly. Additionally, this design permits the elimination of the shim 102 , as the foot of the T-molding need not be completely seated in the second member. In other words, because the T-molding can be secured to the second member with a gap or space remaining between the bottom of the foot 130 and the inner-most part of the second member 130 , height variations can be accounted for without the need for an additional part.
[0090] FIGS. 54-66 show an alternate embodiment of the invention. Specifically, as shown in FIG. 64 , a single-reversible molding element 1001 has an outer face 1005 , which extends over a front face 1007 and a rear face 1009 . This outer surface 1005 is the same on both the front face 1007 and the rear face 1009 , and preferably includes a laminate, but may also be of a foil. While the outer surface 1005 may be limited to only the front face 1007 and the rear face 1009 , the outer surface 1005 may extend across any additional surfaces as well. Due to the novel construction of the reversible molding element 1001 , the versatility of the invention can be greatly increased.
[0091] An example of the versatility of the reversible molding element 1001 is specifically shown in FIGS. 55 and 56 , wherein the significant distinction between FIGS. 55 and 56 is the orientation of the reversible molding element 1001 . In FIG. 55 , the reversible molding element 1001 has its front face 1007 facing outward, while in FIG. 56 , the opposite, or rear face 1009 facing outward. As a result, when the front face 1007 is oriented outward, reversible molding element 1001 functions as a hard surface reducer. In contrast, when reversible molding element 1001 is reversed, and the rear face 1009 is oriented outward, the reversible molding element 1001 functions as an end-molding. Thus, when the T-molding is put together in a single package with the reversible-molding element 1001 , the combination can be used as either a hard surface reducer or an end molding, in contrast to other systems which require three independent pieces to accomplish the same result.
[0092] When using two parts instead of three, maximum use of materials is accomplished, making the invention more economical to produce and, as a result, more environmentally friendly sound. This new configuration of two pieces allows a third piece to be introduced, also reversible, that broadens the use of the pieces to include a increased range of flooring thicknesses found in such products as hardwood and other finished flooring that could not be previously accommodated. An additional option that increases the range of use of the invention is to permit it to transition to a broader range of flooring thicknesses by adding a second reversible part that is higher (thicker) than the first reversible part.
[0093] In FIG. 54 , there is a tongue/groove connection in the attachable parts, for example, on the underside of the T-molding. However, it is within the scope of the invention to reverse the position of each of the tongue and groove from that illustrated. This figure shows the reversible molding element 1001 in a configuration with the track and shim, as optionally used in the other embodiments discussed herein.
[0094] In FIG. 57 the underside of the T-molding does not have a tongue or groove. It does, however, have a notch or shoulder, which holds the other molding piece, such as the reversible molding element 1001 , from moving laterally toward the track. The reversible molding element 1001 , preferably, is smooth, without a groove or tab on the surface which comes into contact with the underside of the T-molding. The underside of the reversible molding element 1001 preferably has a groove to accommodate an extension from the track that stabilizes the lateral movement of the reversible molding element, preventing movement away from the track. In order to hold the element 1001 in place, the track can be provided with a gripping flange 1010 , which may be formed as a break-away section on the remainder of the track, such that when the gripping flange 1010 is not to be used, it can be easily removed to have the track in a different configuration.
[0095] FIG. 58 shows both a groove and stabilizing notch on the underside of the T-molding, with a tab on the reversible molding element 1001 .
[0096] FIG. 59 shows an extendable track extension 1012 , which may be one piece or with break-away elements, and may also act as a shim to raise the track. When used as one piece, the raised tab, on the extension that affixes to the underside of the reversible molding element 1001 , can slide beneath the finished flooring when the track is used to hold a T-molding or the height of the tab can be the equivalent to the height of underlayments used in the floating floor application, and will not interfere with the floating floor, because the extension is no higher than the foam underlayment commonly used in such installations, the apparatus does not interfere with the floating floor. When used with the break-away feature, the extension can be removed and the remaining part can be used as a shim to raise the track to accommodate a thicker floor. The track may be joinable with a tongue/groove connection system to prevent relative movement. FIGS. 60 and 62 show a similar attachable extension using thinner material and a different attachment configuration.
[0097] In FIG. 61 , the underside of the T-molding does not have either a tongue or groove. It does, however, have a notch or shoulder that holds the reversible molding element from moving laterally toward the track. The reversible molding element may also be smooth, i.e., no tongue or groove, on the surface that comes into contact with the underside of the T-molding. These parts can be assembled with any type of glue or adhesive, such as fresh glue, pre-applied glue, encapsulated glue, reactive adhesives, contact adhesives or adhesive tapes.
[0098] In FIG. 63 , the T-molding has a milled groove 1012 . The top of, for example, the reversible molding element also has a groove 1014 . To complete assembly, a loose double-sided tongue 1016 can be pressed into the groove 1012 as the reversible molding element 1001 is attached to the tongue 1016 . The tongue 1016 can be pressure fit or glued into one or both of the grooves 1012 , 1014 .
[0099] The two different sizes of elements 1001 of FIGS. 65 and 66 allow for accommodation of a wide range of thicknesses;
[0100] In FIG. 67 a , there is a groove and stabilizing notch on the underside of the T-molding, and a tab on the reversible molding element 1001 (not shown). Here, the T-molding can accommodate either reversible parts (such as those shown in FIGS. 65 and 66 ), and a shim can be used with an extension (which can be broken away or folded under the shim) to increase its thickness to raise the track and accommodate thicker flooring. FIG. 67 b shows the break-away shim extension with tabs that can snap to the underside of the shim.
[0101] FIGS. 68-80 utilize the reversible concept with aluminum or other metals or composites. Generally all of the same features of the previously described materials can be used with these elements. These structures may additionally be covered, at least in part, by a décor layer (which may be, optionally directly, digitally printed and coated or a décor sheet which can be subsequently coated), such as a foil or other laminate structure.
[0102] FIG. 69 shows two grooves in the T-molding and two matching tongues on the second or reversible molding element. Again, the location of the tongue/groove of any embodiment described herein can be swapped without departing from the invention.
[0103] FIG. 70 shows a T-molding with one single foot and a track to accommodate this foot, similar to FIGS. 1A and 1B .
[0104] FIG. 71 shows a T-molding and a reversible molding element with grooves that can accommodate a clip 1020 that joins the two parts together. The clip has a similar function as the double-tongue of FIG. 63 .
[0105] FIG. 72 shows a reversible molding element with a tab on the top and groove on the underside to accommodate a track extension and aid the prevention of lateral movement, similar to that which is shown in FIG. 57 .
[0106] In FIG. 73 , the T-molding is provided with serrated grooves 1022 which match similar grooves 1024 on the reversible molding element. These grooves may be serrated “inwards” to hinder pulling-out of the reversible molding element, or inwards, to hinder the reversible molding element from being pushed inward, i.e., toward the foot of the T-molding. Alternate embodiments which differ from the traditional tongue/groove connection are shown in FIGS. 75 and 76 . The T-molding can have a notch or shoulder and the reversible molding element can have a corresponding tongue to prevent lateral movement away from the track. The pieces may also be smooth and held together with an adhesive, as described elsewhere herein, or may be held together using only the track extension.
[0107] In FIG. 74 , the track is shown with an extension as a break-away section, similar to that which is shown in FIGS. 60 and 62 .
[0108] FIGS. 77-80 show a metal or composite stair nose attachment in accordance with the invention.
[0109] In FIG. 77 , the stair nose is attached to a T-molding, which need not be formed from an aluminum. This structure may be from HDF, MDF, plastic, or other metal or composite materials. Such composites can include combinations of wood based and plastic resin composites. Hidden fasteners, which are not visible from the surface of either element can be used to secure the elements to the subfloor. There can also be a track to hold the elements in place.
[0110] In FIG. 78 , the stair nose is a separate piece apart from the T and the track. It can be fastened to the subfloor or stair tread with screws through apertures 1030 integrated into the structure of the stair nose. The separate track can be secured to the subfloor also with separate screws. Additionally, the same screws may be used to affix the track and the stair nose. The T-molding can be attached to the stair nose by the tongue and groove and can be held to the subfloor or stair tread by the track.
[0111] FIGS. 79 and 80 show the stair nose and track as one piece. While the track and stair nose can be separately formed, and joined, for example, by a tongue/groove system, they can also be formed and sold as a single unit.
[0112] FIG. 81 shows a modification of the T-molding of the invention. Specifically, it is possible to remove one of the arms or members from the T-molding to create an end molding or carpet reducer. This T-molding 1801 can be in accordance with any of the embodiments described herein. For example, the T-molding 18801 may be formed from HDF, MDF, metal or composite, and optionally provided with a décor layer, which may be printed or otherwise provided directly on the surface. Additionally, the removable section may be pre-fabricated as a frangible section, as is shown and described in accordance with FIG. 19 . A kit, such as a single package, may also be provided which includes at least two, but preferably all, of the individual parts described herein.
[0113] As shown in FIG. 19 , it is also possible to form the molding 11 , leveling block 40 and stair nose attachment 210 from the same element. Specifically, a generic element, indicated at 300 can be milled, sawed or otherwise constructed with a variety of “break away,” or readily separable, sections 300 A, 300 B, and 300 C. When one or more sections 300 A, 300 B, 300 C are removed, by for example, scoring and snapping, cutting, sawing or simply bending, the individual pieces can result. Preferably, the generic element 300 is initially formed as a unitary structure which is then scored as to provide stress-points to allow the removal of the sections. While not required by the present invention, typically, the removal of the break away sections 300 A, 300 B, 300 C requires a significant amount of physical force or labor, as the remaining structure must maintain its structural integrity. Alternatively, removal of the sections 300 A, 300 B, 300 C may require the use of a specialized tool.
[0114] By designing the generic element 300 in accordance with the invention. An installer can manipulate the generic element 300 to produce any needed component. For example, removing sections 300 B and 300 C would produce a typical stair nose attachment 210 , while removing sections 300 A and 300 C would produce a typical molding 11 . Due to this construction, it is possible to manufacture the generic elements to be purchased with appropriate selection being left to the installer. Similarly, when removing sections 300 A and 300 C to form the molding 11 , section 300 A can be used as a leveling block as described herein.
[0115] By allowing an end user to purchase the various pieces as an assembled generic element 300 instead of separate components, the retailers and/or distributors may accordingly reduce their inventory requirements. For example, typically over one-hundred different design patterns for the outwardly facing surface 34 of the molding 11 (as well as for the leveling block 40 and stair nose attachment 210 ) are produced. By allowing for the inventory to include only the generic elements of the invention, the total number of components retained can be reduced from three per design to one per design. Similarly, the installer only need purchase the generic elements 300 , rather than three individual components. This results in savings both to the retailer and installer by reducing the space needed for retailing bays and storage, respectively.
[0116] The molding 1110 may also be provided with a shoulder 1115 , located preferably on the underside of one of the arms 1114 , 1112 . This shoulder can be similar to the stabilizing notch shown in FIGS. 56-61 . The position of the shoulder is typically selected to provide a stop surface to the attachment 1140 to help prevent lateral movement of the attachment 1140 with respect to the molding 1110 . This shoulder 1115 is preferably formed by a beveled cut into the surface, such that when the attachment 40 is seated in shoulder 1115 , movement of the attachment 40 is hindered. The presence of this shoulder 1115 can eliminate any gap or space at the distal or exposed edge of the molding element 1140 , 1250 as it meets the surface of the subfloor or floor element.
[0117] The attachment 1140 can also be provided with one or more spacing gaps 1200 on an undersurface thereof ( FIGS. 86-99 , 100 , 102 , 104 , 106 , 108 and 110 ). When used with an appropriately sized spacer 1210 , the molding 1110 and attachment 1140 can be used with a wide variety of flooring thicknesses, from as small as 6 mm or smaller to as large as 15 mm or larger. The spacers 1210 are typically formed from a rigid or flexible plastic material, preferably, a solid thermosetting plastic. However, it is within the scope of the invention to construct the spacers 1210 of a thermoplastic, such as polyvinyl chloride (PVC) or a resilient foam material. Additionally, the spacer 1210 preferably includes at least one extension 1212 , sized and shaped to fit within a spacing gap 1200 .
[0118] In one embodiment, at least the extension 1212 is formed from a resilient compressible material, such as a structural foam, and is slightly larger in width than the width of the spacing gap 1200 . When the extension 1212 is inserted into the spacing gap 1200 , it is necessary to compress the extension 1212 . Because the extension 1212 in this embodiment must be compressed to be inserted into the spacing gap 1200 , the internal forces of the material of the extension 1212 should maintain the spacer 1210 in the correct position.
[0119] As a substitute for the compressible embodiment or in addition thereto, the spacer 1210 may be joined to the spacing gap 1200 with an adhesive. Typical adhesives include any of the other adhesives discussed elsewhere. However, it is within the scope of the invention to eliminate any means for securing the spacer 1210 in the spacing gap 1200 .
[0120] In a preferred embodiment, a different reversible molding element 1250 can be used, having an end molding surface 1252 and a hard surface reducer surface 1254 and two spacing gaps 1212 a , 1212 b in the lower surface thereof. The presence of one spacing gap associated with each of the molding surfaces allows one spacer 1210 to be used closest to the exposed surface of the reversible molding element 1250 , as shown in FIGS. 94 , 96 and 98 . Although these figures show the reversible molding elements 1250 having two spacing gaps 1200 positioned in an underside thereof, it is within the scope of the invention to utilize a single spacing gap 1200 positioned, for example, centrally or not centrally, i.e., off center, in the underside of the reversible molding element 1250 .
[0121] Typically, the height of the reversible molding element 1250 or 1140 permits the molding 1110 to rest parallel to the higher surface element 1111 when used with an appropriately sized spacer 1210 . In order to provide such appropriately sized spacers 1210 for a variety of different applications, the spacer 1210 may include a second extension 1212 . As shown, for example in FIG. 98 , the extensions 1212 ′ are preferably located on opposite sides of the spacer 1210 , such that inverting the spacer 1210 allows insertion of the correct extension 1212 into the spacing gap 1200 . It is also considered within the scope of the invention to provide the spacer 1210 with up four or more extensions 1212 of different lengths to permit use in a large number of different installations.
[0122] It should be understood that the spacer 1210 is not necessary. The shape of the molding element 1140 and/or reversible molding 1250 allows an installation wherein the molding element 1140 , 1250 rests directly on the subfloor. In certain installations, depending in part on the height of the adjacent flooring elements, this can cause the molding 1110 to form an angle with the flooring elements. However, such an angle is not problematic, as clamps 1126 used in accordance with the invention are preferably versatile enough to sufficiently grip the foot 1116 of the molding 1110 despite the presence of such an angle.
[0123] By utilizing the embodiments shown in FIGS. 100-111 , it is possible to eliminate a gap 1300 between the subfloor and the molding by providing the molding 1140 , 1250 with an angled cut 1305 . The moldings 1140 , 1250 depicted in these figures are similar to that which are shown in FIGS. 112-119 with the same undercut. However, the foot 1116 that fits into the clamp 1126 is longer than the foot 1116 of FIGS. 112-119 .
[0124] The embodiment of FIGS. 112-119 differs from prior designs in a variety of ways. The molding 1110 can be made thicker to provide additional-strength, as well as to allow for easier placement of an undercut 1150 . This undercut 1150 is preferably located on the portion of the molding 1110 that rests on a surface of the finished flooring. In some embodiments, the undercut 1150 provides close contact, i.e., no gap, between the surface of the floor and the outer edge of the molding 1110 as the flooring increases in thickness and raises the molding 1110 from a horizontal position to a more angular position, as described above.
[0125] Additionally, the clamp 1126 and pad 1120 configuration may be replaced by a reconfigured track 1126 ′ as shown, for example, in FIG. 114 . In this embodiment, the clamp 1126 and pad 1120 are combined into a single structure, which structure is secured to the subfloor and grips the foot 1116 of the molding 1110 . Preferably, the track 1126 ′ has a general H-shape, with two upstanding sections 1128 and a middle horizontal section 1130 . As the pad 1120 may also be used in an inverted orientation to achieve multiple configurations, the track 1126 ′ may also be inverted for the same purpose. Accordingly, in a preferred embodiment, the middle horizontal section 1130 is not placed exactly at the middle of the heights of the upstanding sections. Thus, when the molding 11 , 1110 is inserted into the track 1126 ′, the lowest point of the foot 16 , 1116 can be supported by the middle horizontal section 1130 . The entire structure of the track 1126 ′ can be formed from a resilient, but structural material, just as the clamp 26 , 1126 may be.
[0126] The track 1126 ′ may be secured to the subfloor though a variety of methods. In one embodiment, as shown, for example, in FIG. 116 , one or both of the upstanding sections 1128 may have a base 1132 which can be secured to the subfloor with a screw or nail or adhesive. A fastener may also be positioned through the middle horizontal section 1130 to secure the lowermost portions of the upstanding sections to the subfloor.
[0127] The invention additionally includes packaging to be used by, for example, wholesalers or retailers. In one embodiment, multiple individual pieces, e.g, a reversible molding 1250 , a molding 11 , 1110 , a pad 1120 and a clamp 1126 may be bundled in a single package or kit. In another embodiment, the package or kit includes two, or three, or even up to twenty or more, of each piece packaged therein. For example, a single package may include three approximately one-meter (or three foot) sections of each item contained therein, for a total length of about three meters (about nine feet). It is additionally within the scope of the invention to include different sets of items in a single package, for example, one set being about one meter (about three feet) long and an additional set being about two meters (about six feet) long.
[0128] It should be apparent that embodiments other than those specifically described above may come within the spirit and scope of the present invention. Hence, the present invention is not limited by the above description.
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The invention is a joint cover assembly for covering a gap adjacent an edge of a panel that covers a sub-surface, and a method of covering such a gap. The assembly includes a molding having a foot, a first arm, and a second arm. The foot is positioned along a longitudinal axis of the molding, and the first arm extends generally perpendicularly to the foot. The second arm may also extend generally perpendicularly to the foot. A tab depends from at least one of the first and second arms. At least one of the tab and the foot engage a track in order to position the assembly over the gap. The method includes the steps of placing the foot in the gap, pressing the respective panel engaging surfaces into contact with respective panels, and configuring at least one of the tab and the foot to cooperate to retain the molding in the gap when the assembly is in an installed condition.
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BACKGROUND OF THE INVENTION
[0001] The present invention relates to an information processing apparatus, an information processing method, and a program. More particularly, the invention relates to an information processing apparatus, an information processing method, and a program whereby the contents of image data recorded on a storage medium such as a cassette tape are readily verified.
[0002] Image data picked up by a digital video camera are recorded on a DVC (digital video camera) cassette tape loaded in the camera. At a later date, a user may wish to verify the contents of the image data recorded on the cassette tape. In such a case, a personal computer may be used to display a list of image data retained on the cassette tape. A program for running the computer for the purpose performs a number of steps: playing back the cassette tape on fast forward so as to acquire the image data therefrom, detecting discontinuities in the acquired image data, and displaying images representative of the discontinuities so as to indicate a list of the image data held on the cassette tape.
[0003] One disadvantage of the arrangement above is that the program does not guarantee the quality of the image data reproduced from the tape on fast forward. That is, some data required for detecting the discontinuities can get lost, which makes discontinuity detection inaccurate. Another disadvantage is that if the discontinuities were detected from normally reproduced image data, the detection would be performed with precision but it would take an inordinately long time because the entire range of the cassette tape needs to be played back normally.
[0004] Furthermore, when thumbnail (bit map) images are obtained from the image data to represent their contents in a visually easy-to-understand manner, the quality of the thumbnails tends to be poor since they are based on the image data reproduced on fast forward. On the other hand, using the normally reproduced image data to prepare thumbnail images would require too much time.
[0005] Although it is possible to enter a list of image data recorded on each cassette tape into a database or like facility, the cassette tape in question cannot be associated automatically with that image data list because cassette tapes are given no unique definition information (i.e., identifiers) in a format readable by a personal computer. To ascertain whether an image data list corresponds to a given cassette tape has so far required that the user visually check the label or other indications on the cassette tape in question. The proceedings have proved bothersome and time-consuming.
SUMMARY OF THE INVENTION
[0006] The present invention has been made in view of the above circumstances and provides an information processing apparatus, an information processing method, and a program whereby the contents of image data recorded on a storage medium such as a cassette tape are readily ascertained.
[0007] According to an aspect of the present invention, there is provided an information processing apparatus including: retrieving element for retrieving storage medium information and image data information from a memory formed integrally with a storage medium having image data recorded thereon; recording element for recording to a database the image data information in conjunction with the storage medium information, the image data information having been retrieved by the retrieving element; and displaying element for displaying the storage medium information and the image data information recorded by the recording means.
[0008] According to another aspect of the present invention, there is provided an information processing method including the steps of: retrieving storage medium information and image data information from a memory formed integrally with a storage medium having image data recorded thereon; recording to a database the image data information in conjunction with the storage medium information, the image data information having been retrieved in the retrieving step; and displaying the storage medium information and the image data information recorded in the recording step.
[0009] According to still another aspect of the present invention, there is provided a program for causing a computer to carry out the steps of: retrieving storage medium information and image data information from a memory formed integrally with a storage medium having image data recorded thereon; recording to a database the image data information in conjunction with the storage medium information, the image data information having been retrieved in the retrieving step; and displaying the storage medium information and the image data information recorded in the recording step.
[0010] The information processing apparatus, information processing method, and program according to the invention retrieve storage medium information and image data information from a built-in memory of a storage medium containing image data, record the retrieved image data information to a database in conjunction with the storage medium information, and allow the recorded storage medium information and image data information to be displayed. The inventive scheme thus permits easy verification of the contents of image data recorded on the storage medium such as a cassette tape.
[0011] The above and other objects, features and advantages of the present invention will become apparent from the following description and the appended claims, taken in conjunction with the accompanying drawings in which like parts or elements denoted by like reference symbols.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] [0012]FIG. 1 is a block diagram showing a typical structure of a personal computer to which this invention is applied;
[0013] [0013]FIGS. 2A and 2B are explanatory views of MIC information acquired by the personal computer of FIG. 1;
[0014] [0014]FIG. 3 is an explanatory view depicting a typical structure of a database used by the personal computer of FIG. 1;
[0015] [0015]FIG. 4 is an explanatory view indicating another structure of the database used by the personal computer of FIG. 1;
[0016] [0016]FIG. 5 is a flowchart of steps performed by the personal computer of FIG. 1 in retrieving MIC information;
[0017] [0017]FIG. 6 is a flowchart of steps carried out by the personal computer of FIG. 1 in acquiring thumbnail images;
[0018] [0018]FIG. 7 an explanatory view of a thumbnail image acquisition list used by the personal computer of FIG. 1;
[0019] [0019]FIG. 8 is an explanatory view of an MIC-ID detected in step S 39 of FIG. 6;
[0020] [0020]FIG. 9 is an explanatory view illustrating another structure of the database used by the personal computer of FIG. 1; and
[0021] [0021]FIG. 10 is a block diagram showing a typical hardware configuration of the personal computer.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0022] [0022]FIG. 1 is a block diagram showing an internal structure of a personal computer 1 that runs an image data information acquisition program (i.e., an application) embodying the invention.
[0023] The personal computer 1 works as an image data information acquisition apparatus by running the image data information acquisition program under an operating system such as Windows (registered trademark) 2000. As shown in FIG. 1, the personal computer 1 is connected via an IEEE 1394 bus (shown in FIG. 10) to a digital camcorder (camera-integrated DVTR (digital video tape recorder)) 2 acting as an image pickup/playback device. The camcorder 2 is loaded with a cassette tape 3 .
[0024] The cassette tape 3 incorporates an MIC (memory in cassette) 4 . Image data picked up by the camcorder 2 are recorded on the cassette tape 3 . The MIC 4 is constituted illustratively by a flash memory that accommodates information unique to the cassette tape 3 (called the cassette information hereunder) or information about the image data held on the cassette tape 3 (called the image data information hereunder). Details of such information will be discussed later with reference to FIGS. 2A and 2B.
[0025] Under control of an operation control unit 11 in the personal computer 1 , the camcorder 2 retrieves the cassette information or image data information from the MIC 4 built in the cassette tape 3 , and transmits to the personal computer 1 a transport stream of image data retrieved from the cassette tape 3 and compressed by MPEG-2 (Moving Picture Experts Group Phase 2) standards.
[0026] The operation control unit 11 communicates with the camcorder 2 in accordance with IEC (International Electrotechnical Commission) 61883-1. Further, the operation control unit 11 monitors the status of the camcorder 2 and controls its operation using a command set described in the AV/C Tape Recorder/Player Subunit Specification, Version 2.1. Furthermore, the operation control unit 11 acquires the cassette information or image data information retrieved by the camcorder 2 from the MIC 4 and supplies what is acquired to a database management unit 12 .
[0027] Based on the cassette information or image data information from the operation control unit 11 , the database management unit 12 searches through an information database 13 for relevant information, or records the cassette information or image data information to the database 13 . Further, the database management unit 12 causes a display unit 14 to display information held in the information database 13 .
[0028] A control unit 15 controls the personal computer 1 as a whole where thumbnail images are to be acquired from the image data recorded on the cassette tape 3 loaded in the camcorder 2 , as will be discussed later with reference to FIG. 6.
[0029] A stream reception analysis unit 16 includes a TS (transport stream) reception unit 21 , a stream separation unit 22 , an ID detection unit 23 , a decoding unit 24 , and a temporary image storage unit 25 . The TS reception unit 21 receives from the camcorder 2 a transport stream composed of compressed MPEG-2 image data (video stream) containing an MIC-ID, and supplies what is received to the stream separation unit 22 .
[0030] The stream separation unit 22 reconstitutes a video elementary stream (image stream) from the transport stream and feeds the reconstituted stream to the ID detection unit 23 . In turn, the ID detection unit 23 detects the MIC-ID (to be discussed later with reference to FIGS. 2A and 2B) from the video elementary stream and compares the detected MIC-ID with the previously detected MIC-ID in order to detect an MIC-ID discontinuity.
[0031] The decoding unit 24 decodes an I-picture that appears for the first time after detection by the ID detection unit 23 of the MIC-ID discontinuity from the video elementary stream. The decoded I-picture along with the MIC-ID in effect at that point is stored as a thumbnail image into the temporary image storage unit 25 by the decoding unit 24 . Having accommodated the MIC-ID and thumbnail image, the temporary image storage unit 25 notifies the control unit 15 that the MIC-ID and thumbnail image have been acquired.
[0032] Described below with reference to FIGS. 2A and 2B is the information held in the MIC 4 incorporated in the cassette tape 3 .
[0033] The information stored in the MIC 4 (called the MIC information hereunder) is made up of two kinds of information: cassette information shown illustratively in FIG. 2A, and image data information depicted in FIG. 2B.
[0034] The cassette information is individualized information about each cassette tape 3 . The cassette information includes a cassette serial number, the last MIC-ID, and a cassette label. The cassette serial number is unique to the cassette tape 3 of interest. The last MIC-ID is an MIC-ID (to be described later by referring to FIG. 2B) assigned to the most recently recorded image data among the image data retained on the cassette tape 3 . When new image data are recorded to the cassette tape 3 , the last MIC-ID is replaced by the MIC-ID allocated to the newly added image data. The cassette label is constituted by a character string and a display attribute displayed as the label of the cassette tape 3 . Cassette labels are entered by the user through an input unit 49 such as a keyboard (FIG. 10).
[0035] The image data information concerns each of data items making up the image data recorded on the cassette tape 3 . The image data information includes a recording start point, a recording end point, an MIC-ID, and a recording date and time. The recording start point refers to that location on the cassette tape 3 from which the image data item in question starts being recorded; the recording end point signifies that location on the cassette tape 3 at which recording of the image data item of interest has ended. The MIC-ID is a unique number assigned to the image data item. The recording date and time are self-explanatory; they indicate the date and time at which the image data item in question was recorded.
[0036] Retrieving the MIC information allows the personal computer 1 to acquire the cassette information unique to the cassette tape 3 and the image data information about the image data recorded on the cassette tape 3 . The acquired image data information is written to the information database 13 in conjunction with the cassette information.
[0037] How the image data information is managed in the information database 13 will now be described by referring to FIGS. 3 and 4.
[0038] The information database 13 holds at least a cassette master table shown in FIG. 3 and a recording table depicted in FIG. 4. The cassette master table has the last MIC-ID's and cassette labels arranged in conjunction with cassette serial numbers. The cassette master table in FIG. 3 is shown managing the cassette information (see FIG. 2A) as part of the MIC information. Illustratively, an information item “a” in the table indicates that the cassette tape having a cassette serial number “0x3567a4ee01” has the last (i.e., the most recently assigned) MIC-ID “0x4800” pointing to a cassette tape labeled “Kindergarten Graduation Ceremony.”
[0039] Meanwhile, the image data information (FIG. 2B) as another part of the MIC information is managed using the so-called recording table as shown in FIG. 4. In the recording table, the image data information is arranged in conjunction with cassette serial numbers. Illustratively, an image data information item “c” in the recording table indicates that an image data item recorded on the cassette tape having the cassette serial number “0x3567a4ee01” is assigned an MIC-ID “0x0001”; that recording of the image data item in question starts at a location “0x37a219” and ends at a location “0x37ff82” on the cassette tape; that the image data item was recorded on Mar. 10, 2001 (recording start date) starting at 9:00:02 (recording start time); and that the image data item includes a star-shaped thumbnail image. By contrast, an image data information item “d” is shown having no thumbnail image.
[0040] Given the user's instructions, the database management unit 12 outputs the cassette master table and recording table from the information database 13 to the display unit 14 . In turn, the display unit 14 displays the cassette master table and recording table having been received.
[0041] Described below with reference to the flowchart of FIG. 5 is how an MIC information retrieval process is carried out by the image data information acquisition program running on the personal computer 1 . The process is executed every time immediately after the personal computer 1 is booted up.
[0042] When the image data information acquisition program is initiated, the operation control unit 11 establishes connection with the camcorder 2 in step S 1 and issues a MEDIUM INFO command to the camcorder 2 . In response to the command, the camcorder 2 notifies the operation control unit 11 whether or not a cassette tape is loaded inside.
[0043] Given the notice from the camcorder 2 , the operation control unit 11 judges whether or not the camcorder 2 is loaded with the cassette tape 3 from which to retrieve image data information in step S 2 . If the cassette tape 3 is found loaded in the camcorder 2 , step S 3 is reached.
[0044] In step S 3 , the operation control unit 11 issues an OPEN MIC command and a READ MIC command to the camcorder 2 . In response to the commands, the camcorder 2 retrieves cassette information (FIG. 2A) as part of the MIC information read from the MIC 2 in the cassette tape 3 , and transmits the retrieved cassette information to the operation control unit 11 . The operation control unit 11 forwards the received cassette information to the database management unit 12 .
[0045] In step S 4 , the database management unit 12 judges whether or not the cassette serial number in the cassette information is already recorded in the information database 13 . If the cassette serial number is judged already recorded in the information database 13 , then step S 5 is reached.
[0046] In step S 5 , the database management unit 12 compares the last MIC-ID corresponding to the cassette serial number in the cassette information read in step S 3 , with the last MIC-ID in the cassette master table (FIG. 3) retained in the information database 13 . In step S 6 , the database management unit 12 checks to see whether or not the two last MIC-ID's are different.
[0047] If in step S 6 the last MIC-ID retrieved from the MIC 4 is judged different from the last MIC-ID in the cassette master table already recorded in the information database 13 , that means new image data have been added to the cassette tape 3 . If that is the case, the database management unit 12 requests the operation control unit 11 to retrieve image data information from the MIC 4 .
[0048] The request sent by the database management unit 12 to read the image data information from the MIC 4 causes the operation control unit 11 to retrieve the image data information (FIG. 2B) as another part of the MIC information from the MIC 4 in the cassette tape 3 in step S 7 . The retrieved image data information is supplied to the database management unit 12 .
[0049] In step S 8 , the database management unit 12 compares the supplied image data information from the operation control unit 11 with the image data information in the recording table of the information database 13 in terms of their MIC-ID's, and updates only the different image data information. During this MIC information retrieval process, the thumbnail images in the recording table are not updated.
[0050] If in step S 4 the cassette serial number is not judged recorded yet in the information database 13 , the MIC information retrieval process is regarded as carried out for the first time on the cassette tape 3 in question. In that case, step S 9 is reached in which the database management unit 12 records anew the cassette information to the information database 13 .
[0051] In step S 10 , the database management unit 12 requests the operation control unit 11 to retrieve the image data information from the MIC 4 . Given the request, the operation control unit 11 retrieves the image data information as part of the MIC information from the MIC 4 in the cassette tape 3 in step S 10 . The retrieved image data information is fed to the database management unit 12 . In step S 11 , the database management unit 12 records to the information database 13 the image data information supplied from the operation control unit 11 .
[0052] Step S 12 is reached following step S 8 or step S 11 . In step S 12 , the database management unit 12 causes the display unit 14 to display the updated cassette master table and recording table.
[0053] If in step S 2 the cassette tape 3 from which to retrieve image data information is not judged loaded in the camcorder 2 , then the operation control unit 11 disconnects connection with the camcorder 2 and terminates the process. At this point, the display unit 14 may be arranged to display an error message.
[0054] If in step S 6 the last MIC-ID retrieved from the MIC 4 is judged to be the same as the last MIC-ID held in the cassette master table in the information database 13 , then the database management unit 12 recognizes that no new image data have been recorded to the cassette tape 3 and that there is no need to update any information in the information database 13 . In that case, the database management unit 12 notifies the operation control unit 11 of termination of the process. In turn, the operation control unit 11 disconnects connection with the camcorder 2 and brings the process to an end.
[0055] The steps described above allow the user easily to verify and update the contents of the image data recorded on each cassette tape 3 , whereby image data management is accomplished more easily than before. Because no processing is performed on the already-retained cassette information and image data information, the time required for information registration is appreciably shortened.
[0056] A thumbnail image acquisition process is described below with reference to the flowchart of FIG. 6. This process is carried out on the assumption that the MIC information retrieval process, discussed above by referring to FIG. 5, has already been executed. When the user gives necessary instructions through the input unit 49 such as a keyboard (to be discussed later with reference to FIG. 10), the control unit 15 takes over a major portion of control over the process.
[0057] In step S 31 , the control unit 15 causes the operation control unit 11 to acquire the cassette serial number of the cassette tape 3 from the camcorder 2 .
[0058] In step S 32 , the control unit 15 causes the database management unit 12 to acquire, from the recording table (FIG. 4) in the information database 13 , all image data information corresponding to the cassette serial number obtained in step S 31 .
[0059] In step S 33 , the control unit 15 selects only the image data information without thumbnail (bit map) images from all image data information acquired in step S 32 , and prepares a list such as one shown in FIG. 7. The control unit 15 then rearranges the list entries in the ascending order of their recording start points (the list is called the thumbnail image acquisition list hereunder).
[0060] In the thumbnail image acquisition list of FIG. 7, image data information items “d” and “f” are seen associated with the same cassette serial number “0x3567a4ee01” (of the cassette tape 3 ). The recording start points of the image data information items “d” and “f” are “0x3800e2” and “0x39b165” respectively, indicating that the items of image data information are arranged in the ascending order of their recording start points. It is also shown that the image data information items “d” and “f” have no recorded thumbnail images yet. In FIG. 7, the items or entries whose counterparts are shown in FIG. 4 discussed above are given like reference numerals, and their descriptions are omitted where redundant.
[0061] In step S 34 , the control unit 15 causes the operation control unit 11 to issue a REWIND command to the camcorder 2 . Given the command, the camcorder 2 rewinds the cassette tape 3 loaded inside.
[0062] In step S 35 , the control unit 15 causes the stream reception analysis unit 16 to start operating. In step S 36 , the operation control unit 11 under control of the control unit 15 causes the camcorder 2 to play back the cassette tape 3 on fast forward. The stream reception analysis unit 16 , once started, operates continuously until it is instructed to terminate its processing.
[0063] With the cassette tape 3 being played back on fast forward in step S 36 , the camcorder 2 transmits to the personal computer 1 a transport stream of compressed MPEG-2 image data (video stream). In step S 37 , the TS reception unit 21 receives the transport stream from the personal computer 1 and forwards the received stream to the stream separation unit 22 .
[0064] In step S 38 , the stream separation unit 22 reconstitutes a video elementary stream out of the input transport stream. The video elementary stream is supplied to the ID detection unit 23 .
[0065] In step S 39 , the ID detection unit 23 detects an MIC-ID from the input video elementary stream. This MICID is written in the format shown in FIG. 8 at a location of “extension and user data (2)” stipulated in the ISO/IEC 13818-2: 1995 6 Video Bit-stream Syntax and Semantics 6.2.
[0066] [0066]FIG. 8 illustrates a syntax of “user_data( )” recorded in conjunction with an MPEG-2 image data item. In FIG. 8, the second line “user_data_start_code” points to that location on the cassette tape 3 at which this image data item starts being recorded. The third line “neo_id” is an ID representing the camcorder 2 that has recorded the image data item in question. The fourth line “search_data 13 id” shows that if the value is “0x01,” then the image data item is subject to search. The fifth line “mic_id_LSB (least significant bit)” indicates low-order eight bits of the MIC-ID for the image data item in question. The sixth line “mic_id_MSB (most significant bit)” indicates high-order eight bits of the MIC-ID for the image data item. The seventh line “marker_bit” is used to prevent confusion with a start code of MPEG data. The eighth line “frame_count” represents a serial number allocated to an image data item in an image data sequence reproduced from the tape on fast forward. The ID detection unit 23 detects “mic_id_LSB” and “mic_id_MSB” as the MIC-ID.
[0067] In step S 40 , the ID detection unit 23 checks to see if the detected MIC-ID differs from the previously detected MIC-ID. If the two MIC-ID's are judged different, then step S 41 is reached. If there is no previously detected MIC-ID (i.e., if the MIC-ID is detected for the first time), the subsequent processing is the same as when the two MIC-ID's are found to differ from each other.
[0068] If in step S 40 the detected MIC-ID is judged identical to the previously detected MIC-ID, then step S 37 is reached again and the subsequent steps are repeated.
[0069] MIC-ID's have different values for different cuts of image data and thus represent a discontinuity in case of a mismatch therebetween. A detected MIC-ID discontinuity permits detection of a boundary between different cuts of image data.
[0070] If the detected MIC-ID is judged different from the previously detected MIC-ID, step S 41 is reached as described above. In step S 41 , the ID detection unit 23 extracts from the video elementary stream an I-picture that appears for the first time after the detected MIC-ID has been found different from the previously detected MIC-ID, and supplies what is extracted to the decoding unit 24 . The decoding unit 24 decodes the received I-picture and reduces in size the decoded picture into a thumbnail image. The thumbnail image along with the detected MIC-ID is sent to the temporary image storage unit 25 for storage.
[0071] In step S 42 , the ID detection unit 23 notifies the control unit 15 that the MIC-ID and the thumbnail image of the image data identified by that MIC-ID have been acquired. In step S 43 , the control unit 15 judges whether or not the reported MIC-ID exists in the thumbnail image acquisition list prepared in step S 33 . If the MIC-ID in question is judged to exist already in the list, then step S 44 is reached. In step S 44 , the control unit 15 acquires the thumbnail image corresponding to the MIC-ID from the temporary image storage unit 25 , and causes the database management unit 12 to record the acquired image to the information database 13 in conjunction with the MIC-ID in question.
[0072] If in step S 43 the reported MIC-ID is judged absent in the thumbnail image acquisition list, then step S 44 is skipped (the thumbnail image need not be retained because there already exists the thumbnail image in the information database).
[0073] In step S 45 , the control unit 15 erases the thumbnail image held in the temporary image storage unit 25 .
[0074] In step S 46 , the control unit 15 judges whether or not the reported MIC-ID is the same as the MIC-ID of the last image data in the thumbnail image acquisition list. If the two MIC-ID's are judged different, that means there still exists a thumbnail image of image data to be acquired. In that case, step S 37 is reached again and the subsequent steps are repeated. If in step S 46 it is judged that the reported MIC-ID is the same as the MIC-ID of the last image data in the thumbnail image acquisition list (in which image data items are arranged in the ascending order of their recording start points), then step S 47 is reached. In step S 47 , the control unit 15 causes the stream reception analysis unit 16 to stop operating. Also under control of the control unit 15 , the operation control unit 11 cause the camcorder 2 to stop playing back the cassette tape 3 .
[0075] In step S 48 , the database management unit 12 under control of the control unit 15 causes the display unit 14 to display the updated recording table as shown in FIG. 9. Whereas the recording table of FIG. 4 above was shown having no thumbnail image recorded for the image data information item “d,” a square-shaped thumbnail image is seen recorded for the corresponding item in the recording table of FIG. 9. The user can verify the newly recorded thumbnail image by viewing what is displayed on the display unit 14 .
[0076] As described, the newly recorded image data alone are subjected to the thumbnail image acquisition process whereby an additional thumbnail image is retained in conjunction with the added image data. As opposed to conventional setups that create thumbnail images of all image data, the inventive scheme processes only what is necessary and thereby shortens appreciably the time required for thumbnail image preparation.
[0077] Furthermore, utilization of the I-picture extracted from the image data reproduced from the tape on fast forward helps improve the quality of thumbnail images.
[0078] [0078]FIG. 10 is a block diagram showing a typical hardware configuration of the personal computer described as performing the series of steps above.
[0079] In FIG. 10, a CPU (central processing unit) 41 carries out diverse processes based on the programs held in a system memory 42 or on the programs loaded from a hard disc drive 51 into the system memory 42 . The system memory 42 also accommodates data needed for the CPU 41 to execute its processes. The system memory 42 is controlled by a memory controller 43 . A graphics controller 44 controls a display 45 constituted by a CRT (cathode ray tube) or an LCD (liquid crystal display) for image display.
[0080] The CPU 41 , memory controller 43 , and graphics controller 44 are interconnected via a system bus 46 . A PCI bus controller 47 is also connected to the system bus 46 .
[0081] The PCI bus controller 47 is connected to a PCI bus 48 . The PCI bus 48 is further connected with a USB controller 50 for controlling the input unit 49 including a keyboard and a mouse, with a hard disc controller 52 for controlling the hard disc drive 51 , and with an IEEE 1394 bus controller 53 . The IEEE 1394 bus controller 53 is connected via an IEEE 1394 bus 54 to the camcorder 2 . Given suitable instructions, the IEEE 1394 bus controller 53 exchanges control commands and MPEG-2 transport streams with the camcorder 2 over the IEEE 1394 bus 54 .
[0082] In this specification, the steps which are stored on a storage medium and which describe the programs to be executed represent not only the processes that are carried out in the depicted sequence (i.e., on a time series basis) but also processes that are conducted parallelly or individually.
[0083] As many apparently different embodiments of this invention may be made without departing from the spirit and scope thereof, it is to be understood that the invention is not limited to the specific embodiments thereof except as defined in the appended claims.
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An information processing apparatus is disclosed which includes: a retrieving element for retrieving storage medium information and image data information from a memory formed integrally with a storage medium having image data recorded thereon; a recording element for recording to a database the image data information in conjunction with the storage medium information, the image data information having been retrieved by the retrieving element; and a displaying element for displaying the storage medium information and the image data information recorded by the recording element.
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This is a continuation in part of U.S. patent application Ser. No. 102,207, filed Aug. 5, 1993, now U.S. Pat. No. 5,413,181.
This invention relates to a rake attachment with scarifying teeth for a skid steer loader.
BACKGROUND OF THE INVENTION
Grounds preparation for seeding and lawn installation is a part of most building and construction projects. Preparing soil for seeding and lawn installation involves grading, filling, leveling and scarifying the soil around buildings, side walks, trees and other obstacles. Conventional industrial and commercial earth moving equipment is designed to operate in large open areas, thus they are not well suited for operation in confined areas or around the edges of buildings and other structures. Consequently, most of the finishing work around buildings and confined areas is still performed by laborers with hand tools. Utilizing conventional skid loaders or skid steers as they are commonly known has decreased the amount of hand work involved in lawn and grounds preparation. As a small utility loader, the skid steer is well adapted for precision earth moving operations in confined areas. Skid steers have hydrostatic transmissions with four independent wheels, which allows the skid steers to pivot in place. Skid steers also include hydraulic controlled lift arms and pivoting attachment assembly, which can be operated simultaneously while driving skid steers.
A skid steer can be fitted with various attachments to perform a variety of earth moving functions; however, no single skid steer attachment has been developed to address all the operational needs of the lawn or grounds preparation industry. Bucket attachments are ideal for transporting loads of soil to low lying areas, but are ill suited for spreading the soil radially across the low lying area. The conventional blade type attachment allows the skid steer to grade but does not drag soil or scarify effectively. The bulk of conventional buckets and blade type attachments obstruct the operators view of the ground being worked. Mechanical scarifying rakes have been developed for use with skid steers; however, these scarifying rakes have complex mechanical parts, which are often subjected to stress, which results in damage and often failure. The articulated mechanical scarifying rakes are large and cumbersome, which makes them difficult to operate in confined areas, such as around building and other obstacles. The operator's view of the ground being worked is obstructed by the bulk of the mechanical attachments. Furthermore, the scarifying rakes are ineffective at moving soil to low lying areas. Since no single attachment is suitable for all the lawn preparation functions; namely grading, filling, leveling, scarifying and vegetation removal the skid steer attachments must be frequently interchanged during use at the job site. Transporting multiple attachments is cost ineffective.
SUMMARY OF THE INVENTION
The rake attachment of this invention allows a conventional skid steer to be used for all lawn preparation functions: grading, filling, leveling and scarifying. The design of the rake attachment allows the skid steer to push as well as pull soil. Consequently, the rake attachment can be used to grade soil off of high areas, to push soil into low areas, and to scarify the soil to a seeding ready finish. The rake attachment eliminates the mechanical complexity of other attachments and the inconvenience of frequently changing attachments to perform various earth moving functions. The design of the rake attachment also maximizes the operator's field of vision for precision operation around buildings and other confined areas.
This rake attachment includes a frame and a replaceable elongated toothed rake blade having a row of rigid spaced teeth along its forward edge. The frame includes a mounting plate for connecting the frame to the pivot plate of the skid loader and a forward lateral support member connected by a pair of spaced side members. The rake blade is mounted to the forward support member. The positioning of the rake blade and the open configuration of the frame provide the operator an unobstructed view of the ground being worked.
The rake attachment of FIGS. 8-12, in addition to the elongated frame with spaced tines, further includes a plurality of longitudely spaced ground penetrating scarifying teeth that extend from the frame at a ground engaging angle that forms substantially a right angle from the tines comprising the rake blade. The scarifying teeth permit deep penetration and scarifying of the earth while still permitting the tines comprising the rake blade to level and work the soil. The scarifying teeth may be removed from the support member and stored when scarifying is not desired.
Accordingly, an object of this invention is to provide for a novel and unique multi-purpose rake attachment for use with a skid steer loader.
Another object is to provide a rake attachment for a skid steer, which is suitable for pushing and pulling soil during grading, filling, leveling, scarifying and vegetation removal.
Another object is to provide for a low maintenance rake attachment for a skid steer, which reduces the complexity and number of components and allows a clear line of vision to the ground being worked.
Another object is to provide for deeply scarifying the soil while at the same time permitting the soil to be smoothed and worked.
Still another object is to permit scarifying teeth to be attached to the rake for deeply scarifying soil, but permitting such scarifying teeth to be removed when scarifying is not necessary.
Other objects will become 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 only wherein:
FIG. 1 is a perspective view of a skid steer with the rake attachment of this invention;
FIG. 2 is a top plan view of the rake attachment;
FIG. 3 is a side elevation view of the rake attachment;
FIG. 4 is a side elevation view of the skid steer with the rake attachment in an elevated position above a pile of soil;
FIG. 5 is a side elevation view of the skid steer with the rake attachment performing a searifying operation;
FIG. 6 is a side elevation view of the skid steer with the rake attachment grading soil in a push/pull position;
FIG. 7 is a side elevation view of the skid steer with the rake attachment dragging soil in a push/pull position and for vegetation removal;
FIG. 8 is a fragmentary perspective view of a skid steer with a rake attached thereto pursuant to another embodiment of the invention;
FIG. 9 is a cross-sectional view taken substantially along lines 9--9 FIG. 8;
FIG. 10 is a fragmentary side elevational view of the rake according to FIGS. 8 and 9 illustrated in its ground engaging and scarifying position;
FIG. 11 is an enlarged view of the circumscribed portion of FIG. 9; and
FIG. 12 is a fragmentary side view of the scarifying tooth and attachment mechanism illustrated in FIG. 11.
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 herein. 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 its teachings.
FIGS. 1-7 show the rake attachment 20 of this invention used with a conventional skid loader or skid steer 2. Rake attachment 20 is shown used on a skid steer 2 manufactured by Melroe Company under the trademark "BOBCAT" although rake attachment 2 can be adapted for use with any make or model of skid steer.
Skid steer 2 includes a chassis 4, which has an operator's compartment 5. Skid steer 2 preferably uses the conventional hydrostatic transmission with four independently driven wheels 8. The transmission is operated by two steering hand levers 6. Chassis 4 supports two pivotal lift booms or arms 10, which are raised and lowered by a pair of hydraulic lift cylinders 11. Lift arms 10 are pivoted about a horizontal axis between a raised position (FIG. 4) and a lowered position (FIG. 5). A cross brace 12 connects arms 10 in front of operator compartment 5. A pivot assembly 14 is pivotally mounted to the front end of lift arms 10. Pivot assembly 14 includes a pivoting mounting plate 16, which carries an attachment connecting mechanism (not shown). A pivot cylinder 17 has its extensible rod 18 connected between mounting plate 16 and cross member 12 as by clevis 19. Pivot cylinder 17 shifts mounting plate 16 about a second horizontal axis between an up position (FIG. 4) and a down position (FIG. 5). As shown in FIG. 7, mounting plate 16 is substantially vertical when the lift arms 10 are in the lowered position and rod 18 is retracted. Mounting plate 16 is angled with respect to the horizontal when lift arms 10 are in the lowered position and rod 18 is extended out from cylinder 17. The lift and pivot cylinders are operated by two foot pedals (not shown) located within the operator compartment. As commonly known but not shown in the figures, mounting plate 16 carries a locking mechanism, which locks the various attachments to the mounting plate. The locking mechanism is not shown or described in detail and any conventional mounting mechanism can be used to secure the rake attachment of this invention to mounting plate 16.
As common in conventional skid steers, skid steer 2 can be operated in a float mode, wherein lift cylinders 11 are disabled to allow lift arms 10 to rest in a lowered position under their own weight and supported by chassis 4. Consequently, no additional downward force is introduced by lift cylinders 11. In the float mode, only the pivot cylinder 17 is operative, thereby reducing the number of operation controls to occupy the operator's attention. Rake attachment 20 is designed to take full advantage of this feature during finishing operations as detailed later in this specification.
As shown in FIGS. 2 and 3, rake attachment 20 includes a forward support member 22 connect to a mounting saddle 40 by a pair of spaced side support members 30. Forward support member 22 is preferably an elongated L-shaped angle bar with a lower forward side 26 and a raised back 24. Forward support back 24 is preferably of sufficient height to prevent loosened soil from kicking over the upper edge 25 of forward support member 22, while not substantially impairing the operator's line of sight to the rake blade 50.
Mounting saddle 40 is of conventional design and can adapted for connection to any type of mounting plate 16. Mounting saddles 40 are standardized for various models of skid steers 2 to accommodate various attachments. Mounting saddle 40 includes a pair of connection plates 44 connected by a cross member 42. Cross member 42 forms a down turned upper lip 43. Each connection plate 44 has a plurality of mounting holes 45. Each connection plate 44 also includes a rearwardly extending peripheral ridge 46 along the outer lower edges, which conforms to the contour of mounting plate 16. During the mounting process of rake attachment 20 to skid steer 2, ridge 46 serves to align mounting saddle 40 with mounting plate 16. As shown best in FIG. 1, the upper lip 43 engages the upper edge of mounting plate 16. The back surface of mounting saddle 40 rests flat against the front surface of mounting plate 16. Mounting saddle 40 is then locked into place against mounting plate 16 by the skid steer's locking mechanism (not shown) carried on mounting plate 16.
As shown in FIGS. 1-3, side support members 30 are spaced apart to define a central opening 31. Each side support member 30 includes a upper extension part 32 and a lower side gussets 34 centrally connected to its upper extension part. Upper extension parts 32 are connected between the upper edge 25 of forward support back 24 and the upper edges of each connection plate 44. Each side gusset 34 has four side edges 36-39, which define a substantially triangular configuration with a truncated forward fourth side. Each truncated forward edge 36 is connected as by welds to the rear face of forward support back 31. The opposite rear edges 37 are connected as by welding to the front face of each connection plate 44. The upper edges 38 are connected as by welding to the bottom of each upper extension members 34. The lower edged 39 extend diagonally between the lower edge of the support back 31 and the lower edges of each connection plate 44.
As shown in FIGS. 2 and 3, rake attachment 20 includes an elongated tined or toothed rake blade 50 connected to a frame 30 as by fasteners 58, 59. Rake blade 50 is mounted to the bottom face of forward support member 22. Rake blade 50 is defined by interconnected rectangular panel sections 52. Each panel section 52 is bolted to rake support member 22 by bolts 58, which extend through aligned bores in panel sections 52 and lower forward side 26, and nut fasteners 59, which are affixed to bolts 58. Rake sections 52 are connected to forward support member 30 in this fashion to allow ready replacement of individual panel sections. Each panel section 52 is of flat rectangular shape with a serrated forward edge, which forms a plurality of elongated tines or teeth 56. Panel sections 52 are cut or cast from any durable and rigid metal, such as iron or steel. Panel sections 52 are preferably hardened to provide additional tensile strength. Teeth 56 are straight and rigid to allow the teeth to bite into hard soil without bending or breaking and withstand the drag force exerted by the motion of the skid steer and the weight of lift arms 10. The contour and spacing of teeth 56 prevent rocks, foliage and other debit material from collecting between the teeth, which is common in drags and other attachments with coiled tines.
As seen in the figures, rake attachment 20 has a relatively small and compact design, which allows skid steer 2 to manipulate in tight areas. Rake attachment 20 uses no moving parts to effect all operational aspects, which enhances its valve in field operations. Furthermore, the design rake attachment 20 is easy to store or transport when detached from the skid steer 2.
Rake attachment 20 is designed to take advantage of the float mode operation of skid steer 2. Rake attachment 20 is fully operational without the assistance of the lift cylinders 11. Operation of the skid steer 2 in the float mode allows the operator to manipulate rake attachment 20 through all of its operational positions using only the pivot control foot pedal. Consequently, the operation of the rake attachment and skid steer is simplified. Using only the pivot control pedal to perform the ground work simplifies the task of the operator and avoids confusion between the lift and pivot control pedals. Since rake attachment 20 can operate solely with pivot cylinder 17, its operation is less taxing on the skid steer's hydraulic systems, which translates into increased performance and life span of skid steer 2.
FIG. 4 shows skid steer 2 with rake attachment 20 in the elevated position. In the elevated position, pivot cylinder 17 draws mounting plate 16 back towards skid steer 2, so that mounting plate 16 is substantially vertical and perpendicular to the ground. In the elevated position, rake blade 50 is spaced two to three feet above the ground and approximately three feet from the bottom edge of mounting plate 16. The lower diagonal edges 39 of side gussets 34 are slanted upward at approximately a 55 degree angle to the ground. The upward slant of lower diagonal edges 39 provides front end clearance, so that skid steer 2 can be positioned adjacent to small piles of earth with teeth 56 extend over the top of a pile of soil 70, as shown in FIG. 4. In the elevated position, the operator has a clear view of the worked ground and soil 70 around side support members 30 and though central opening 31.
FIG. 5 shows skid steer 2 with rake attachment 20 in the lowered or scarifying position. In the scarifying position, pivot cylinder 17 fully extends mounting plate 16 so that mounting plate 16 is pivoted beyond horizontal and rake blade 50 engages the ground perpendicularly. The rotation of mounting plate 16 and the connected rake attachment 20 to the scarifying position forces lift arms 10 to be raised slightly from their lowered position. The weight of lift arms 10 and the vertical position of rake blade 50, provides an ideal position for scarifying soil. Under the influence of gravity, the weight of lift arms 10 is transferred directly through rake blade 50. The combined weight of lift arms 10 and rake attachment 20 embeds teeth 56 into the soil and scars the soil as the skid steer moves backward. In scarifying position, lift arms 10 and mounting plate 16 are substantial horizontal and provide a clear unobstructed view of the entire rake blade 50. Consequently, the operator can directly monitor the depth and effectiveness of each skid steer pass.
FIGS. 6 and 7 show the skid steer 2 with rake attachment in an intermediate or push/pull position. Again as seen in FIGS. 6 and 7, the design of rake attachment 20 provides the operator with a clear view of the approximate area of ground being worked. The soil can be viewed over the top of rake attachment 20, around side support members 30, or through central opening 31. In the push/pull position, mounting plate 16 is pivoted between its up and down positions, wherein lower diagonal edges 39 of side gussets 34 are approximately horizontal and parallel with the ground. In the push/pull position, rake blade 50 engages the ground at an acute angle, approximately at a 30 degree angle. The angle at which the rake blade engages the ground can be adjusted by further lowering mounting plate 16. As pivot plate 16 rotates past the rake blade's contact point with the ground, lift arms 10 are slightly raised from their lowered position to place the weight of the arms on teeth 56.
In the push/pull position, rake attachment 20 can be used to grade soil by pushing rake blade 50 forward or to drag soil by pulling soil backward. As shown in FIG. 6, forward movement of skid steer 2 pushes teeth 56 across the top layer of soil, which turns up a volume of soil along the way. The loosened soil gathers above rake blade 50 and in front of forward support member 22 as skid steer 2 moves forward. Forward support back 31 prevents the soil from moving over the top of the rake support, and does not obstruct the operators view of the ground being worked or rake blade 50. Rocks embedded in the soil are drawn up and accumulate on the top of forward support member 22. The contour, spacing and rigidity of teeth 56 allow rocks to be dislodged from the soil, but not lodged between teeth 56. Conventional rakes use coils chisels or tines, which flex under the friction of the skid steer movement, allowing rocks to lodge in between the chisels and tines. Adjusting the angle at which rake blade 50 engages the ground varies the amount of soil graded with each pass.
FIG. 7 shows soil dragged behind rake attachment 20 as skid steer 2 moves backward. As skid steer 2 moves backward, a small volume of soil is pulled backward by the under side of rake blade 50 and forward support member 22. The spacing between teeth 56 allows small amounts of loose soil to pass through, which gives a raked soil appearance. Increasing or decreasing the angle of pivot plate 16 increases or decreases the attitude of rake attachment 20 to vary the amount of soil dragged.
Referring now to the alternate embodiment of FIGS. 8-12, elements the same or substantially the same as those in the embodiment of FIGS. 1-7 retain the same reference character, but increased by 100. Referring now to FIGS. 8-12, a plurality of tubular sockets indicated by the numeral 160 are spaced evenly along the back 24 of support plate 122. Each of the sockets 160 define a vertically extending opening 162 which slidingly receives a scarifying tooth 164. Each of the scarifying teeth are substantially rectangular bars having a tapering ground penetrating end 166 which joins with side edge 168 at corner 170. As will be discussed hereinafter, the tapering end 166 and edge 170 permit the scarifying teeth 164 to chisel into hard ground to facilitate scarifying. Each of the teeth 164 is provided with an aperture which registers with apertures 174, 176 on the opposite sides of each of the sockets 160. A retaining pin 178 is inserted through the apertures 174, 176 and through the aperture in the corresponding tooth 164 to retain the corresponding scarifying tooth 164 in its corresponding socket 160. The retaining pin 178 is maintained in its position by a linch pin 180 which is received within an aperture 182. A ring 184 extends through an opening in the linch pin and is freely movable with respect thereto. Ring 184 is attached to another ring 186 on the other end of the pin 178 by a chain 188. Accordingly, each tooth 164 is installed in its corresponding socket 160 by inserting the pin 178 through apertures 174, 176, and through the corresponding tooth 164. The linch pin 180 is then installed in the aperture 182 with the ring 184 deflected out of the way. When the ring 184 is released, it sags to a point that prevents the linch pin 180 from vibrating out of the aperture 182. A washer 190 is installed on the other end of the pin to prevent the pin from being inserted into the apertures 172, 174, 176 so far that the socket 160 interferes with the ring 186.
In operation, the scarifying teeth penetrate the ground when the support member 122 is disposed at any ground working angle, such as that illustrated in FIG. 10. Each of the teeth 164 are rectangular bars of substantial thickness and thus, because of beveled edge 160, are able to chisel into the ground and scarify the ground during both forward and backward movements of the skid steer. As the teeth 164 are scarifying the ground, the tines 156 smooth and work the ground as it is being scarified. If scarifying is not desired, the teeth 164 may be removed from the fork member 122 by removing the linch pin 180 of each tooth and then removing retaining pin 178. The teeth 164 can then be removed from their sockets 160, and are then conveniently stored on pins 192 which project from lower support braces 194 which are a part of side support members 130 and extend between back 124 and lower cross bar 196 which interconnects the side support members 130 and also extends between the connection plates 144.
Scarifying can also be accomplished with the scarifying teeth 164 removed by moving the rake to the scarifying position illustrated in FIG. 7 to use the tines 156 for scarifying, but the tines 156 are unable to penetrate the ground to the same depth as do the scarifying teeth 164 and obviously the tines 156 are not then available to level and work the soil as it is scarified.
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A rake attachment for use on a skid steer, which can be used for multiple lawn and grounds preparation activities, such as grading, filling, leveling and scarifying. The rake attachment of this invention combines several useful attachment functions into a single compact design. The rake attachment includes a support frame that has spaced side support members to define an opening through which a skid steer operator may view the soil being worked. Scarifying teeth extend from the support frame to penetrate the ground for scarifying. The support frame includes tines which work and level the soil as it is being scarified by the scarifying teeth.
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BACKGROUND OF INVENTION
Power tools, such as saws, trimmers and pruners have been used for some time to cut and shape trees and bushes. To increase their versatility, these tools have been placed on the end of poles so that elevated sections of trees or bushes can be reached for cutting without having to use a ladder or other similar device. In many cases, the power tool is simply placed on the end of a long single pole to provide the necessary extension. However, the typical length of an extension pole makes it is difficult to transport and store. Furthermore, placing the entire power tool at the end of an extension pole makes it difficult to balance, and extremely unwieldy because all of the weight is at the end of the pole.
Manufacturers have attempted to overcome the burdensome pole length by using a telescopic pole that can be compressed into a smaller space. However, telescoping poles have a decreasing diameter along their length, thus providing a structurally weaker pole at the narrower sections. This increases the likelihood that the pole will break and creates a safety hazard for the user.
Furthermore, manufacturers have attempted to solve the uneven weight distribution of the power tool by distributing weight at both ends of the pole. This has been done by placing the power tool portion at one end, and the power source portion (i.e. gas tank, battery, etc.) at the other. However, this solution typically entails having a continuous mechanical drive train or an electrical conductor (i.e. wire) connecting the tool end and the power supply end. This continuous connection often cannot be separated or shortened in conjunction with a telescopic or separable pole.
Therefore, it would be advantageous to provide an extensible pole that can be separated into smaller components for easier transport and storage. It would be further advantageous to provide an extensible pole having uniform diameter and strength.
SUMMARY OF INVENTION
The present invention is directed to an elongated pole saw for cutting and trimming trees, bushes and the like. The saw comprises three detachable sections, that when assembled, form an extended length saw having a battery pack on one end, and a saw or other power tool at the other end. The pole saw includes a first section containing a handle and battery pack, a second extension section, and a third section that contains the saw itself. Each of the sections contains an electrical wire that is terminated at the ends of the pole sections and are attached to adjacent pole sections via a male plug and female receptacle. In this way, the battery pack in the first section of the pole is able to deliver power through the second section to the saw in the third section.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows an assembled pole pruner of the present invention;
FIG. 2 shows a disassembled pole pruner of the present invention;
FIG. 3 shows a pole pruner of the present invention with an intermediate pole section removed;
FIG. 4A shows a male plug of a pole section;
FIG. 4B shows a female receptacle of a pole section;
FIG. 4C shows the female receptacle of FIG. 4B with a sleeve pulled rearwardly;
FIG. 5A shows a male plug of a second pole section;
FIG. 5B shows a female receptacle of second pole section;
FIG. 6A shows a cut-away view of the male plug of FIG. 4A ;
FIG. 6B shows a cut-away view of the female receptacle of FIG. 4B ;
FIG. 7A shows the male plug of an alternative embodiment of the invention; and
FIG. 7B shows a female receptacle of an alternative embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A pole saw 10 of the present invention is shown in FIGS. 1 and 2 in an assembled and disassembled state, respectively. The pole pruner 10 includes a first pole section 12 , and second intermediate pole section 14 , and a third pole section 16 . The first pole section 12 includes a soft cushioning material 13 for comfortable gripping of the pole section 12 , a handle 18 , and a battery pack 20 for supplying power to a tool 22 at an end of the third pole section 16 . The tool 22 is shown in the figures as a saw, but it is contemplated that any tool may be placed at the end of the third pole section 16 , and the invention is not limited to a saw.
Each of the pole sections are detachably connected to one another to form a single elongated pole for reaching elevated branches and the like without the need of a ladder. This greatly increases the safety of using such a device because a user does not have to balance himself on a ladder while using the tool.
The pole sections are connected at connecting sections 24 A and 24 B, which comprise female receptacles 26 A and 26 B and male plugs 28 A and 28 B on adjacent ends of each pole section, as best shown in FIG. 2 . The arrangement shown in FIG. 2 allows the second pole section 14 to be removed so that the first pole section 12 can be directly connected to the third pole section 16 , as shown in FIG. 3 . The shortened pole arrangement may be useful when only a short reach is needed, and has the advantage of providing greater control over the pole saw 10 . The preferred embodiment limits the number of pole sections to three, by using keying features on the male plugs 28 A and 28 B and female receptacles 26 A and 26 B, as described in greater detail below. The number of pole section is limited to prevent the pole length from becoming dangerously long. However, it should be understood that any number of pole sections may be used and still fall within the scope of the invention.
The connecting sections 24 A and 24 B will now be described in greater detail. FIGS. 4A and 4B show detailed views of the male plug 28 A and female receptacle 26 A connecting the first pole section 12 and the second pole section 14 , and FIGS. 5A and 5B show the male plug 28 B and female receptacle 26 B for connecting second pole section 14 with the third pole section 16 .
Referring now to FIG. 4A , the male plug 28 A comprises a hollow male housing 29 that is fitted over an end of the pole section 12 and fixedly secured thereto by rivets 31 (see also FIG. 6A ). Although, the male housing 29 is separate from the pole section 12 in the preferred embodiment, it is contemplated that the male housing 29 be made integral with the pole section 12 . The male housing 29 shown in FIG. 4A includes threads 30 on its outside diameter and a front stem 32 extending therefrom. The stem 32 includes two openings 34 , two flat surfaces 36 on opposite sides, and a slot 38 along its length. The openings 34 hold two electrical contacts 40 that extend back through the stem 32 and connect to electrical wires 42 that run the length of the pole section (see FIG. 6A ).
Referring now to FIGS. 4B and 4C , the female receptacle 26 A includes a housing 50 and a threaded sleeve 52 . FIG. 4C shows the female receptacle 26 A of FIG. 4B with the threaded sleeve 52 pulled slightly rearwardly to better reveal the housing 50 . The housing 50 is folded over an end of the pole section 14 and secured on opposite sides by rivets 54 (see also FIG. 6B ). The housing 50 defines an opening 56 for receiving the stem 32 of the male plug 28 A. A rear portion of the opening 56 includes two apertures through which contacts 57 protrude. The opening 56 is generally cylindrical-shaped having flattened portions 58 on opposite sides thereof to correspond to the shape of the stem 32 . The opening 56 further includes cavities 60 for holding the rivets 54 (only one seen in figure) so that they do not interfere with the insertion of the stem 32 into the opening 56 , and a protrusion 62 corresponding to the slot 38 on the stem 32 .
When the stem 32 is inserted into the opening 56 , the protrusion 62 slides into slot 38 , and the contacts 40 engage corresponding contacts 57 . The matching flat portions 36 and 58 on the stem 32 and in the opening 56 , respectively, align the male plug 28 A and female receptacle 26 A and prevent their rotation relative to one another. The slot 38 and protrusion 62 further orients the relationship of the male plug and female receptacle for proper electrical connection.
The threaded sleeve 52 is slidably and rotatably attached to the pole 14 and is prevented from sliding forwardly off of the pole by the housing 50 . The sleeve 52 is threaded on its interior so that when the male plug 28 A is attached to the female receptacle 26 A, the sleeve 52 is slid forwardly so that it overlies and engages the threads 30 of the male plug 28 A.
FIGS. 5A and 5B show the male plug 28 B and the female receptacle 26 B for the second connecting section 24 B, connecting the second pole section 14 to the third pole section 16 . Similar elements in the male plug 28 B and female receptacle 26 B of the second connection section 24 B to the first connecting section 24 A are labeled with identical reference numbers. The difference in the second connection section 24 B is that the stem 32 of the male plug has only a single flat surface 36 , and similarly, the opening 56 in the female receptacle has only a single flat portion 58 . The reason for this is explained below.
The single and double “flat portion” keying feature in the connecting sections 24 A and 24 B allows the pole saw 10 to use three pole sections, as shown in FIGS. 1 and 2 , or two pole sections as shown in FIG. 3 , but prevents the addition of a fourth pole section, ie. another intermediate pole section 14 . The keying feature allows the male plug 28 A (having two flat portions) of the first pole section 12 to be inserted into either the female receptacle 26 A (having a two flat portion) or 26 B (having a single flat portion) of the second or third pole sections 14 and 16 . However, the keying feature prevents a user from adding an additional fourth intermediate pole section, like pole section 14 , because the male plug 28 B of the pole section 14 (which has a single flat portion) does not fit into the female receptacle 26 A (which as two flat portions) of the similarly made pole section 14 . Therefore, a user is prevented from using more than three pole sections and thereby increasing the length of the pole saw.
FIGS. 7A and 7B show an alternative embodiment of the present invention. Here, rather than using corresponding flat portions as a keying feature to prevent rotation, the male housing 28 includes a serrated front face 70 that engages a corresponding serrated face 72 on the female plug 26 . Additionally, this embodiment of the invention uses a single contact 74 on the male plug and a single contact 76 on the female plug. In other respects, the alternative embodiment is identical to the preferred embodiment previously described.
The present invention provides the advantage of having detachable pole sections that can be separated into three shortened smaller sections, making it easier to package and transport. Also, unlike previous telescopic-type devices whose pole section diameters decrease along their length, the pole sections 12 , 14 and 16 of the present invention have the same diameter and consequently, their rigidity and strength are consistent throughout its length. Furthermore, because the power source is at one end and the tool is at another, the weight of the device is divided making the product easier to handle.
Although a preferred embodiment has been disclosed, it should be noted that 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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An elongated pole pruner for cutting and trimming trees, bushes and the like having three separable sections, that when assembled, form an extended length pruner. The pole pruner includes a first section containing a handle and battery pack, a second extension section, and a third section that contains the purner itself. Each of the sections contains an electrical conductor that is attached to corresponding conductor in an adjacent pole sections via a male plug and female receptacle. In this way, the battery pack in the first section of the pole is able to deliver power through the second section to the pruner in the third section.
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CROSS-REFERENCE TO RELATED APPLICATION
This application claims priority pursuant to 35 U.S.C. § 119(e) to U.S. Provisional Application No. 60/328,079, filed Oct. 9, 2001, which application is specifically incorporated herein, in its entirety, by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to methods and systems for producing and playing media programs, and more particularly to a media program with selectable sub-segments.
2. Description of Related Art
The growth in new forms of digital media has led to numerous opportunities to change the method by which audio-visual and like productions are produced and played. Prior to the rise of digital media, analog media programs typically consisted of a continuous stream of audio-visual information sequentially recorded in a medium such as a photographic film or magnetic tape. To play such analog programs, the recording medium is sequentially scanned by a reading and/or projection device to recreate the recorded program in the intended display format, such as on a movie or television screen. All the elements of the recorded program are played in sequence according to the timing and sequence of the original recording. Analog media playing devices may possess relatively limited functions for altering the recorded timing and sequence of a program. For example, video cassette recorders (VCR's) typically have functions for altering a program timeline that are limited to functions such as pause (freeze-frame), fast-forward, and reverse.
Certain digital media standards, however, provide for expanded capabilities with respect to the sequence and timing of programs. For example, expanded features such as branching, multiple camera angles, parental control, video menus, and interactivity are supported by the DVD-Video standard available from the DVD Forum (www.dvdforum.org). Other digital media standards exist. In general, digital media standards support at least a degree of interactivity and control sufficient to permit control of the sequence and timing of selected media segments or frames during playback. In particular, the DVD-Video standard has become prevalent, and media products that include the expanded features listed above are commonly available based on the DVD-Video standard. Such features, however, do not exhaust the possibilities within the DVD-Video standard or other existing or prospective standards. It is desirable to provide additional features to increase consumer interest in media products such as DVD-Video discs, thereby inducing consumers to purchase such products in greater numbers and at more favorable prices.
SUMMARY OF THE INVENTION
The present invention provides additional features for increasing consumer interest in a recorded media product. In particular, the invention provides a method and system for producing or playing a media program with selectable sub-segments. The invention is particularly suitable for implementation within the DVD-Video standard, and may therefore be used with special-purpose media players such as DVD video players.
The selectable sub-segments are accessed using selectable links that appear at predetermined times and for predetermined periods during play of the primary media program. According to an embodiment of the invention, the selectable links are presented in the form of text-based prompts. Graphical icons have been used for similar purposes in the past, but text-based prompts offer numerous advantages over icons. Text-based prompts are used to describe the linked sub-segment, and/or to indicate some other information about the sub-segment. For example, according to an embodiment of the invention, a textual prompt describes and indicates the run-time (duration) of the linked sub-segment. By reviewing the text-based prompt, a viewer may assess the content of the linked sub-segment and decide whether or not to select the segment for viewing. The media player and program are configured such that the viewer may select any desired sub-segment for viewing by performing a viewer operation (e.g., pressing an “enter” button on the media player remote control unit) while the textual link is displayed.
According to another novel embodiment of the invention, multiple selectable links are simultaneously displayed at independently determined times during play of the primary media program. Individual ones of the multiple links may be graphical icons as used in the past, but preferably, text-based prompts are used. The media player is configured so that the viewer may select any one of the multiple links while it is displayed on the screen. A first viewer operation is used to highlight or otherwise indicate individual ones of the links as desired by the viewer. A second viewer operation is then used to select any link while it is indicated (e.g., highlighted) by the viewer, thereby causing a selectable sub-segment associated with the link to play. The use of multiple simultaneous independent links provides for a more complex and richer viewer experience than is possible using only a single link.
The selectable sub-segment of the present invention differs from branching as known in the prior art in that the presence of selectable sub-segments does not alter the storyline of the primary program. In addition, unlike branch selection, a user of the invention is not required to select any sub-segment in order to advance the progress of a program. Instead, the primary program plays normally, and the user is presented with selectable links to sub-segments during the regular program flow. Selection of the links is at the option of the user. Each link is programmed to appear at predetermined times, and for predetermined intervals, during program play. The user may select any given link by performing a predetermined sequence of operations, such as highlighting an icon or sub-title, and then pressing a control button. Selection of a link causes the primary program to be interrupted by a sub-segment associated with the selected link. The sub-segment is then played until finished or otherwise terminated, and then the primary program resumes playing from the point of interruption.
The program content of the sub-segments is virtually unlimited. For some applications of the invention, individual sub-segments may contain content related to various scenes, themes, actors and actresses, dialogue, etc., that are present in the primary program. For example, one sub-segment may contain commentary from a well-known expert concerning an underlying theme of the program; another sub-segment may contain an additional scene or segment that was cut from the primary program, with or without a director's commentary; another sub-segment may contain an actress's comments about a particular scene; another sub-segment may contain a “behind-the-scenes” look at the filming of a scene, and so forth. Such an application may be designed to appeal particularly to serious media consumers who are interested in viewing a program more than once, and in obtaining more information about a program. Such consumers are particularly likely to rent or purchase DVD-discs, and the addition of features according to the invention may create an additional inducement to do so.
It should be appreciated that the invention is not limited to such applications, and is particularly suitable for any application for which it is desirable to support a primary, essentially self-contained program with supplemental information or scenes. For example, a released movie version may be supported by scenes from an “uncut” version; a mystery movie may be supported by additional information about clues or characters; a serial program (such as a soap opera or mini-series) may be supported by scenes from past episodes; an educational or documentary program may be supported by explanatory or expanded commentary; and so forth. Furthermore, while it is generally desirable to make the sub-segments easily accessible to consumers of the media product, in some cases it may be desirable to hide or encode links to sub-segments that are not easily discovered, thereby creating a product with both “mainstream” and “insider” appeal. Thus, the invention provides a method and system of potentially wide applicability in the entertainment market, and that consumers may come to expect and demand with products such as DVD video discs.
In particular, the use of text-based prompts for the links creates an opportunity to provide the viewer with greater convenience and control over the viewing experience. Mere icons that convey limited or no information about the linked sub-segment are generally not preferred, because the user is required to temporarily exit the primary program to determine the content of the linked sub-segment. If the viewer is not interested in the sub-segment, the viewer is left with the feeling of having wasted time and has interrupted the viewing of the primary program for no reason. Using a descriptive prompt as the link enables the viewer to decide in advance whether a particular sub-segment is of interest, without interrupting the primary program.
It should be apparent that the descriptive links, multiple links, and the combination thereof will enable creation of richer and more complex media products. For example, multiple thematic threads carried by different groups of sub-segments may be interwoven with a primary media program. A more specific example of this is a program wherein the primary program tells a story from the perspective of a selected character or narrator, and different threads (groups of sub-segments) supplement the primary program by showing aspects of the story from the perspective of different characters. This richness and complexity may be used to make the media product appeal to a broader, more diverse audience by including different types of sub-segment content with diverse appeal. In the alternative, the media product may be configured for greater depth of appeal to a particular audience. In general, the applications of the invention are limited only by the creativity of writers and producers of media programs. In recognition of these benefits of the invention, a DVD industry award was recently awarded to its inventors.
A more complete understanding of the media program with selectable sub-segments will be afforded to those skilled in the art, as well as a realization of additional advantages and objects thereof, by a consideration of the following detailed description of the preferred embodiment. Reference will be made to the appended sheets of drawings which will first be described briefly.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of a system for producing and playing a media program with selectable sub-segments.
FIG. 2 is a diagram illustrating logical relationships between elements of a media program with selectable sub-segments.
FIG. 3 is a flow chart showing a method for playing a media program with selectable sub-segments.
FIG. 4 is an exemplary screen shot taken during play of a media program according to the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The present invention provides a media program with selectable sub-segments, that is particularly suitable for implementation in digital formats such as DVD-video. As used herein, media program means a discrete information set including at least one primary program for continuous play. A primary program is a portion of a media program that creates a defined continuous dynamic output, such as a motion picture or video, when played in an appropriate media player. For example, in DVD formats, primary programs are sometimes referred to as a “main feature” or a “featured presentation.” As used herein, primary program does not refer to information for generating merely static displays of information, such as still photographs or web pages.
A segment is a portion of a media program and is of relatively short duration compared to a primary program. Like a primary program, a segment also creates a defined continuous output when played, and not merely a static display of information. Sub-segment refers to an independent segment of a media program that is separate from the primary program, and is not used to refer to a portion of a segment.
A link is a portion of a media program that creates an audible, visible, or both audible and visible indicator during a defined interval of a primary program. A link in the instant context should be distinguished from hyperlink or link as used in computer networking contexts. In a networking context, a link or hyperlink contains an address for linked information. In the context of a self-contained media program, a link need not contain an address (although it may), and principally serves as an indicator that an associated sub-segment may be accessed during the interval of a primary program for which the link is displayed. A link may be a graphical icon or a textual prompt. Although it is usually preferably to use descriptive text in link, the invention is not limited thereby particularly when multiple simultaneous links are used.
The foregoing definitions are not intended to limit the scope of the invention, but to clarify terms that are well understood by persons having ordinary skill in the art. It should be appreciated that the defined terms may have other meanings to such persons of ordinary skill in the art. These and other terms are used in the detailed description that follows.
Referring to FIG. 1 , a system 10 for producing and playing a media program according to the invention is depicted. System 10 comprises a collection of raw audio-visual data 11 , which may be in various digital formats. Data 11 may be obtained directly from digital input devices, such as digital video cameras, or may be obtained by digitizing analog data. The data 11 is typically organized into discrete segments, each of which bears a unique identifier. Data 11 serves as input data for program authoring system 12 . The authoring system may be any suitable system known in the art. For example, software for suitable authoring systems is available from Sonic Solutions of Novato, Calif. (www.sonic.com). Authoring software is preferably run on a general purpose computer equipped for media applications, as known in the art. The authoring system 12 is used to select and arrange the elements of the media program as desired by the program directors. Using the authoring system, the director creates the desired media program, which is typically output as a digital master tape in a high-definition format. Preferably, the output is compatible with an established standard, such as DVD-Video.
The media program becomes input for encoder 13 , which is used to encode and optionally to encrypt the media program as known in the art, in preparation for writing to the digital media 14 . Like authoring system 12 , encoder 13 may comprise a general purpose computer running commercially available encoding software. Encoding may be done in various formats. For current DVD applications, the preferred format is MPEG-2, although other formats, such as MPEG-1, MPEG-2 Progressive Profile, H.263, or MPEG-4 may be used. Likewise, the digital media 14 may be of various forms. Presently, a common digital media is digital video disc (DVD). However, alternative media, such as digital tape, HD-DVD, or FMD (fluorescent multi-layer disc), may be used if desired. The encoded data is optionally encrypted.
The digital media may then be played using an appropriate media player. Typical media programs for movie videos require well in excess of 1 gigabyte of storage space, after being encoded, and are currently best suited for playing in dedicated media players such as DVD video players. Media players are currently available to read digital media formatted according various standards, including DVD-Video, DVD-Audio, and audio CD. The media player outputs a signal for a suitable output device 16 , such as a television configured to accept a video signal according to a 525/60 (NTSC) or 625/50 (PAL/SECAM) standard, for viewing by a user. Alternative output devices may include a display device such as a CRT, passive matrix flat panel display, active matrix flat panel display, or CRT projection system, coupled to appropriate electronics for receiving any suitable video signal and processing the signal for creating a video display on the display device.
It should be appreciated that the digital media 14 , media player 15 , and output device 16 need not be physically near each other. In the case of a present-day DVD videodisc player, these elements are usually near each other. However, these elements may be separated by great distances if connected by a signal of sufficient bandwidth. For example, the digital media may be located at a remote site, and the encoded media program may be streamed to a media player at the user's location. In the alternative, both the media player and the digital media may be located remotely, and the video signal streamed or transmitted to the output device at the user's location. In the latter case, the user communicates with the media player via a remote connection.
FIG. 2 is a diagram illustrating logical relationships between elements of a media program 20 with selectable sub-segments 41 - 46 (six of many shown). The particular arrangement shown in FIG. 2 is exemplary, and it should be appreciated that an unlimited number of alternative arrangements may be provided that will conform to the logical relationships illustrated by the example. A primary program consists of a sequence of segments 21 - 24 (four of many shown). The sequence of the primary program segments 21 - 24 defines a timeline 30 , running from left to right in FIG. 2 . A time T 0 on the timeline coincides with the initiation of the first primary program segment 21 . Program time may be determined as known in the art. Preferably, the primary program segments are inherently chronologically determinative, so that increments of time along timeline 30 can conveniently be determined by counting bits from T 0 . A current bit position is preferably retained in a register, and can readily be converted to current program time along timeline 30 .
Dashed line 40 denotes an imaginary line between visible elements of the primary program and the sub-segments, which conceptually reside in a sort of subspace below the primary program. The visible elements of the primary program comprise the segments 21 - 24 and links 31 - 36 (six of many shown). Segments 21 - 24 and links 31 - 36 are tied to the timeline, that is, appear on the output device (video screen) for predetermined intervals. One, and only one segment of primary program segments 21 - 24 can appear (be played) at any particular time. Segment 21 begins playing at time T 0 and plays exclusively until segment 22 is initiated, and so forth.
In comparison, any number of links may appear (be played) simultaneously. For example, links 31 and 32 appear at the same time and for the same interval. Link 33 appears by itself, and links 34 - 36 appear for overlapping intervals. Links may be provided for any desired interval, and links with non-overlapping intervals may be grouped together by track. For example, links 31 , 33 , and 34 may be arranged in a first track; links 32 and 35 may be arranged in a second track; and link 36 may be arranged in a third track. These tracks are conceptual, and do not require creation of physical tracks. Each link is associated with a single sub-segment; however, a sub-segment may be associated with more than one link. For example, sub-segment 41 is associated with link 31 , sub-segment 42 with link 32 , and so forth.
Each link is preferably displayed in the form of a textual prompt. During the editing process that defines the sub-segments, and editor writes a descriptive prompt for each sub-segment that is displayed as, or as part of, the link. That is, the editor may provide any desired description. Optionally, the run-time of the sub-segment may be included as part of the textual description. For example, the descriptions of two simultaneous links may read:
View this scene from the perspective of Mary, Ted's girlfriend. 3:02 Dr. Simon discusses communication problems in relationships. 1:42
In the foregoing examples, “3:02” and “1:42” are the run times of the respective sub-segments, in minutes and seconds, and the descriptive text is self-explanatory.
Association between a link and a sub-segment may be accomplished in any manner compatible with the applicable media standard. Unlike hyperlinks in HTML documents, links in a self-contained media program need not include address information for the linked information. Instead, because the links are determined by the program time, association may be accomplished by determining the current program time and track of each link. For example, during the interval that link 33 appears in the primary program, it can be determined positively that sub-segment 43 is the associated sub-segment, merely by determining the program time, without any additional information.
However, when plural links appear simultaneously, such as during the interval between time T 1 and time T 4 , additional information is needed. For such cases, a track table can be used to determine the association. The predetermined track table may provide that the link on track one (where link 31 appears) during the interval between T 1 and T 4 is associated with sub-segment 41 ; and the link on track two (where link 32 is located) during the same interval is associated with sub-segment 42 . In other words, association of sub-segments may be determined from parallel timelines of each track. Timelined track-based methods may be preferable for ease of implementation within a DVD-Video standard environment. However, other association methods, including addressing, may be preferred for other environments.
During the interval that a link appears, a link may be activated at the option of the user. Preferably, links are activated by accessing an existing command function of the media player, such as by pressing a button on a media player remote control device. However, when only one link appears, it may be automatically activated. When a link is activated, a user may view the associated sub-segment by accessing a second command function of the media player, such as by pressing a second button on the remote control device. For example, at time T 2 , while link 31 is activated, a user selects the appropriate command for viewing the sub-segment 41 . Sub-segment 41 is then played from beginning to end, while the value of T 2 is stored in a memory of the media player. When sub-segment 41 is finished, the media player resumes playing the primary program at time T 2 in segment 22 . The user may then activate a second link 32 and command play of sub-segment 42 at a later time T 3 . As indicated by the position of the return arrow from sub-segment 42 , the user preferably can terminate the sub-segment before it has completed play and return to the primary program at T 3 . Thus, a user is provided with an option to view any of the sub-segments 41 - 46 during allotted intervals.
FIG. 3 is a flow chart showing a method 50 for playing a media program with selectable sub-segments. At step 52 , a primary program of the media program is played in a media player. Play may begin at any program time selected by the user, and program control functions according to the prior art, such as fast-forward, reverse, pause, etc., are preferably fully enabled. At step 54 , links are visibly displayed and/or audibly played at selected, predetermined intervals. Preferably, the links are arranged in at least two logical tracks, so that at least two links can be simultaneously displayed at selected intervals. Any displayed link may be activated by a user, or in the case of a single displayed link, activated automatically. As indicated at step 56 , play is continued until an activated link is selected.
Both activation and selection of links may be accomplished by using a remote control device connected to the media player. The media program may be configured so that selection occurs automatically once a link is activated by a user, but it is generally preferable to have activation and selection separated. Advantageously, separate operations permits a user to activate links in turn, i.e., to toggle between links, without causing an unwanted sub-segment to play.
When a link is selected, the current primary program time, as determined, for example, by a bit position, is stored in a memory of the media player, and play of the primary program is interrupted. A sub-segment associated with the selected link is then played at step 60 . As indicated at step 62 , play of the sub-segment continues until it is exited. Preferably, a sub-segment may be exited at any time at the selection of the user, or the user may permit the sub-segment to play to completion. After the sub-segment is exited, the stored program time is retrieved from memory and the primary program resumes playing from the point where it was last interrupted.
Links may be implemented in the media program in various ways. According to an embodiment of the invention, links are implemented using hard encoded subtitles according to the DVD-Video standard. Hard encoded subtitles are DVD subpictures, which are full-screen graphical overlays. According to the DVD-Video standard, up to 32 subpicture tracks can be turned on to show text or graphics overlaid on the video frame. Accordingly, using the subpicture track, up to 32 independent links may be simultaneously displayed, and any number of links may be controlled using the 32 independent tracks. For most applications, fewer than 32 simultaneous links are preferred. In some embodiments, a maximum of two or three simultaneously displayed links is used, to avoid over-stimulating viewers with too many choices. In general, two or three tracks are usually sufficient for control of the links. According to the DVD-Video standard, each track supports full-screen, run-length-encoded bitmaps with two bits per pixel, giving four color values and four transparency values, selected from palettes of 16 colors and 16 transparency levels, respectively. Subpicture display command sequences can be used to create effects such as scroll, move, color/highlight, and fade. The maximum subpicture data rate is 3.36 Mbps, with a maximum size per frame of 53220 bytes. One skilled in the art will recognize that within these parameters, a large variety of video effects are possible.
Preferably, each link contains information about the specific sub-segment to which it is associated. In particular, each link may provide a textual description of its linked sub-segment. The text of links may be displayed in a complex or sophisticated fashion, such as by being incorporated into a moving graphic or animated text. In some embodiments, it is preferable to use a relatively simple display mode, such as static text, for compatibility with the greatest number of media players. FIG. 4 shows a screen shot 70 according to an embodiment of the invention, wherein each link is displayed as a static text string 76 , 78 appearing in a black bar (matte) 74 a , 74 b of a letterbox format display. Such mattes are used for display of high-aspect ratio (such as 1.85) formatted video 72 in a low aspect ratio (such as 1.33) video screen. Each text string (link) 76 , 78 preferably serves to identify the content of the sub-segment that may be accessed using the link. Additionally, the text may indicate the run-time of the sub-segment, or provide any information about the sub-segment that is of interest for the particular application. The media program is configured so that while the text strings 76 , 78 are displayed using separate subpicture tracks, a user may highlight (change the color or appearance of) any of the displayed text strings using command buttons of the media player. For example, the media program may be configured so that pressing any arrow keys on the remote control of a DVD player causes a highlight to toggle between the displayed links. While the desired link is highlighted, an associated sub-segment may be accessed by pressing a second button, such as an “enter” key. That is, performing a designated operation while a link is highlighted causes the media program to immediately branch to a sub-segment associated with the highlighted link.
In an embodiment of the invention, all of the links can be hidden, redisplayed, and/or inactivated and reactivated by the user during playing of the primary program. In other words, a user may turn access to the sub-segments and the display of their links on or off at will. Limitations of the DVD-Video standard and/or its implementation in particular media players may sometimes create difficulties with media programs according to this embodiment. To avoid such difficulties, a different approach is used in another embodiment of the invention. According to the second embodiment, two versions of the primary program are provided on a media disk: one version without the selectable sub-segments, and one version with the selectable sub-segments. Users who do not wish to view the primary program with the associated sub-segments may merely select the version without selectable sub-segments. According to yet another embodiment of the invention, users are provided with an option to view the sub-segments without viewing the primary program, either by playing the sub-segments in a predetermined order, by selecting specific sub-segments off of a menu or list, or by some combination of the foregoing.
In general according to the foregoing, in an embodiment of the invention a DVD video disc is provided containing encoded audio-visual information according to an accepted standard, such as DVD-Video. The encoded information comprises a primary program, a plurality of independent sub-segments, and a plurality of links in the primary program. Each of the links is associated with an individual one of the sub-segments and is configured to be played during a predetermined interval of the primary program. The encoded information is configured so that, when it is played in a suitable media player, each of the sub-segments is independently and selectively accessible during its associated predetermined interval of the primary program. Access to the sub-segments is by a user-controlled execution of a command function on the video player while a link associated with a sub-segment is being played. The encoded information is further configured so that, when any particular sub-segment is selected for access, the primary program is interrupted by the selected sub-segment at a point of interruption; and when the selected sub-segment is terminated, the primary program resumes play at the point of interruption. Preferably, the encoded information is configured so that more than one link may be played at any time during the primary program. One skilled in the art may create a media disc according to the invention in various ways, including but not limited to using subtitle functions within a DVD-Video or other standard.
Having thus described a preferred embodiment of a media program with selectable sub-segments, it should be apparent to those skilled in the art that certain advantages of the within system have been achieved. It should also be appreciated that various modifications, adaptations, and alternative embodiments thereof may be made within the scope and spirit of the present invention. For example, a method and system for implementation with the DVD-Video standard has been illustrated, but it should be apparent that the inventive concepts described above would be equally applicable to other media standards. The invention is further defined by the following claims.
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A media program for play on a media player to produce an audio-visual stream perceivable by a user is disclosed. The media program comprises a primary program configured for streaming play on the media player. The primary program is divisible into a continuous sequence of segments defining a timeline. The media program also includes a plurality of sub-segments separate from the primary program. Each of the sub-segments is configured for streaming play on the media player. The media program also includes a plurality of links (indicators or signals) in the primary program. Each link is configured to be played for a predetermined period of the timeline and not at other periods of the timeline. The media program is configured to cause the media player to interrupt the primary program and play a predetermined one of the plurality of sub-segments when a predetermined interruption command of the media player is activated by the user while a link associated with the predetermined one of the plurality of sub-segments is being played. Two or more of the plurality of links may be configured to be played simultaneously during the primary program, each associated with a different one of the plurality of sub-segments. Each of the plurality of links may include information descriptive of a sub-segment associated with the each link, such as a brief written description that may be configured to appear in the black bar of a letterbox display. Methods and systems for producing and playing the media program are also disclosed.
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BACKGROUND OF THE INVENTION
The invention relates to a sterilization tray.
Surgical instruments are typically stored, transported and prepared for use in sterilization trays. The trays include rigid enclosing walls to provide protection. The walls are typically perforated with multiple holes to allow ingress and egress of a sterilant, e.g. steam, when the tray is placed in a sterilizer. Typically, the trays are wrapped in paper or cloth to maintain the sterility of the contents in storage. It is desirable for the trays to have smooth exteriors, e.g. rounded corners, ruggedness, light weight, high thermal conductivity, and low cost construction. U.S. Pat. No. 5,882,612 teaches a sterilization tray having plastic end panels or comer pieces to simplify the construction of the tray. The patent points out that trays are typically constructed of stamped and folded sheet metal and that it is extremely difficult, if not impossible, to produce a tray with rounded corners using such a construction.
It is further desirable for the trays to have comfortable gripping surfaces and stackability. Increasingly, such trays are used in conjunction with European DIN standard storage containers. A typical DIN container will contain one or more trays stacked within it. Typical prior art trays include one set of handles for lifting the tray from the DIN container and a second set of handles for carrying the tray.
SUMMARY OF THE INVENTION
The present invention provides a sterilization tray having a smooth exterior, ruggedness, light weight, high thermal conductivity, comfortable gripping surfaces, stackability, and low cost construction. The tray is constructed of stamped and folded sheet metal, but in such a way as to provide rounded corners. This construction makes a rugged, lightweight, and low cost tray. A molded handle insert is attached to the ends of the tray to provide multiple utility of reducing the number of handles required, maximizing space utilization, providing a comfortable gripping surface on the outside and inside of the tray, and providing stackability.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top plan view of a sterilization tray according to the present invention.
FIG. 2 is a perspective view of the inside of the tray of FIG. 1 .
FIG. 3 is a side plan view of the tray of FIG. 1 .
FIG. 4 is a top plan view of a sheet metal stamping prior to folding to form the tray of FIG. 1 .
FIG. 5 is a perspective view of a handle insert component used in the tray of FIG. 1 .
FIG. 6 is a top plan view of the handle insert component of FIG. 5 .
FIG. 7 is a side sectional view of the handle insert component taken along line 7 — 7 of FIG. 5 .
DETAILED DESCRIPTION OF THE INVENTION
FIGS. 1-3 depict an exemplary embodiment of a sterilization tray 2 according to the present invention. The tray 2 includes a bottom wall 4 , upstanding side walls 6 , and upstanding end walls 8 . The walls are joined together to form an open box having rounded corners 9 . The walls include perforations 10 for allowing sterilant, e.g. steam, in and out of the tray. The interior of the tray may include various racks and fixtures for holding instruments as is known in the art. A lid 10 is removably secured to the tray to cover the open top. Preferably the tray is made of a lightweight, thermally conductive, and strong material such as sheet metal, e.g. aluminum. The lid 10 can also be made of sheet metal. However, it is preferably made of a transparent material such as plastic. Each end wall 8 includes elongate handle aperture 12 forming a handle in the sheet metal. A handle insert 14 is attached adjacent the aperture 12 . Preferably the handle insert is attached on the inside of the tray so as to maintain a smooth exterior surface on the tray. Attachment ears 11 formed on the handle insert 14 extend into slots 13 formed in the end wall 8 to secure the handle insert 14 to the end wall 8 . An upper portion 15 of the end wall extends over a portion of the handle insert 14 to reinforce the attachment of the handle insert 14 to the end wall 8 . The upper portion 15 of the end wall adds lifting strength to the handle insert 14 .
The handle insert 14 includes a grip aperture 16 bounded on the top by a gripping surface 18 . The gripping surface has a thickness greater than the thickness of the end wall 8 such that the gripping surface distributes the weight of the tray over a greater area of the users fingers and thus providing a more comfortable handle than the aperture 12 alone. Scalloped fingergrips 20 are advantageously formed in the grip surface 18 . Preferably the aperture 16 extends through the handle insert so that it can be gripped from the inside or outside of the tray. Preferably the handle insert is a low cost, light weight, molded plastic part. An example of a suitable plastic for use in this application is Radel® R polyphenylsulfone manufactured by BP Amoco Chemicals. This material has high strength and can be repeatedly autoclaved.
The extra grip thickness and double sidedness of the handle insert 14 is further advantageous where the tray is to be inserted into another container, e.g. a DIN container. When the tray is inserted into such a container with the end wall 8 closely adjacent the end wall of the container, there is insufficient room to position fingers on the outside of the tray 2 and extend the fingers through the aperture 12 to lift the tray. Likewise, because of the close proximity of the container wall to end wall 8 , without handle insert 14 there would be insufficient space to extend the fingers through the aperture 12 and lift the tray. However, handle insert 14 provides a grip surface 18 that permits a secure grip on the tray from the inside without the fingers needing to extend past aperture 12 .
The handle insert 14 also includes stacking lugs 22 extending upwardly above the top edge of the walls. Corresponding stacking lug receiving holes 24 are formed in the bottom wall 4 of the tray. Thus, when one tray is stacked on another, stacking lug 22 is received in hole 24 to keep the trays from sliding relative to one another.
Tray feet 26 are provided on the outside corners of the bottom wall 4 to space the bottom wall 4 away from a support surface to facilitate circulation of sterilant through the perforations 10 . Preferably the feet are made of a molded plastic material such as Radel® R.
FIGS. 4-7 depict the sheet metal blank 30 and handle insert 14 from which the tray is assembled. As can be seen in FIG. 4, the tray bottom wall 4 , side walls 6 , and end walls 8 are formed from a single piece of stamped sheet metal. The sheet metal blank 30 includes bottom portion 34 , side tabs 36 and end tabs 38 . Bottom portion 34 includes rounded corners 40 . Side tabs 36 extend beyond the bottom portion 34 at each end. End tabs 38 include elongate handle aperture 12 and upper tab 42 .
The tray 2 is formed by first bending a slot 13 in each end of each side tab. The side tabs 36 are then bent upwardly to form a right angle with the bottom portion 34 . The side tabs 36 are bent at each end to form the smooth rounded corners 9 and part of the end walls 8 . In the exemplary embodiment of FIGS. 2 and 3, the sheet metal blank is shaped to produce a gap 35 separating the side tab 36 and the bottom portion 34 . This gap facilitates bending the side tab 36 to match the rounded corners 40 of the bottom portion 34 . The upper tabs 42 are each bent to form a right angle with the end tabs 38 thus forming the upper portions 15 . The end tabs 38 are bent upwardly to form a right angle with the bottom portion 34 and to overlap the side tabs 36 . Preferably the side walls are each bent at each of their ends to form lap joints with the end walls such that the exterior of the side and end walls are flush. Handle insert 14 is placed with attachment ears 11 engaging slots 13 and being trapped within the slots by end tab 38 . Aperture 16 is aligned with aperture 12 and upper portion 15 contacts the top of handle insert 14 . Preferably a recessed shelf 17 is formed in the top of the handle insert 14 to receive the upper portion 15 so that the top of upper portion 15 is flush with the remaining top of the handle insert. End tab 38 and side tab 36 are riveted 44 together above and below slot 13 to hold the tray in rigid alignment. Alternatives to rivets include screws and weld beads and other attachments known in the art. Preferably no rivets are inserted through the handle insert 14 and the handle insert is allowed some freedom of movement within the slots 13 . Thus, when the tray 2 is heated in an autoclave, and the handle inserts 14 and end walls 8 expand different amounts, no breakage occurs.
It will be understood by those skilled in the art that the foregoing has described a preferred embodiment of the present invention and that variations in design and construction may be made to the preferred embodiment without departing from the spirit and scope of the invention defined by the appended claims.
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A sterilization tray has a smooth exterior, ruggedness, light weight, high thermal conductivity, comfortable gripping surfaces, stackability, and low cost construction. The tray is constructed of stamped and folded sheet metal, but in such a way as to provide rounded corners. A molded handle insert is attached to the ends of the tray to provide the multiple utility of reducing the number of handles required, maximizing space utilization, providing a comfortable gripping surface on the outside and inside of the tray, and providing stackability.
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BACKGROUND OF THE INVENTION
[0001] 1. Technical Field
[0002] The present invention is related to portable sanitary sheet for seated toilet bowl that is available for carrying in the pocket or bag and can be used simply by spreading over seat of seated toilet bowl in the rest room. Besides a great deal of advantages of portability, the invention represents more convenient and sanitary properties in utilizing than conventional sanitary sheet for seated toilet bowl.
[0003] 2. Description of the Prior Art
[0004] Except for the case of making a private use of independent personal seated toilet bowl, single seated toilet bowl needs to be used for the people and in this case sanitary problem takes place above all. In other words, when a seated toilet bowl is once used there arises a good possibility that preoccupying person leaves dirts or other foreign substances on seat ( 5 ) making it much unsanitary and causing the other persons to feel uncomfortable in utilizing seat and so it is the most common to use seat either by clearing urine or dirts left on seat ( 5 ) with tissue paper or newspaper or by covering again tissue paper or newspaper on seat after clearing urine or dirts. However these methods are quite inconvenient,
[0005] uncomfortable, unsanitary, and asking too much excessive consumption of tissue paper leading to uneconomical problem.
[0006] As a resolution to the above mentioned problem, sanitary sheet has once been introduced to attach on seat dozens of sheet (made of paper or film) whose reverse side is coated with sticky resin and to utilize in separate piece in need. But this product has been found to have problem because it's inconvenient in use getting wet with rain or detergent when cleaning, unsanitary owing to the possibility of contamination to urine or excrement and much likely to be missing. In addition, due to somewhat high manufacturing cost and difficult process technologies related, it's not commonly applied at present.
[0007] For this reason, another type of product has also been introduced to fold in half and pile in dozens layer sanitary sheets fabricated as FIGS. 4, 4 a inside rectangular-shaped box attached to the wall of the restroom, and take out by piece to use. This can not be used for portable purpose but for the restroom purpose only and therefore it should be noted that the intention of the product is different from that of the present invention.
[0008] Firstly, it's needed to look over conventional sanitary sheet as FIG. 4 . The sheet is shaped to make it enable to pull out the center part of the paper ( 32 ) by forming cutting line ( 31 ) to the oval type of hole in the center except for the restricted area of the rear part. In order to use this right, it is required to spread main body ( 10 ), pull out cutting line ( 31 ) by using both hands, remove the center part of the paper ( 32 ) and then put main body ( 30 ) on seat to use. But in different way it is also available to remove the
[0009] center part of the paper ( 32 ) not completely separated from main body ( 30 ) but partially separated by pulling out cutting line ( 31 ) only. In this case the center part of the paper ( 32 ) is hanging on main body ( 30 ) downwards inside seat. In the same way FIG. 4 a is designed to cut ahead the whole center of main body ( 40 ) with same shape as in FIG. 4 except for the partial area of the rear part on which the center part of the paper ( 42 ) is hanging. Accordingly when spreaded over seat, the center part of the paper ( 42 ) is hanging on main body ( 40 ) downwards inside seat.
[0010] By the way, all these methods are troublesome as the center part of the paper ( 32 , 42 ) contacts with the water inside seat. Because of this, the towards main body ( 30 , 40 ) and reaches up to main body ( 30 , 40 ) thus leading to the uncomfortable and unsanitary result. The users then find the way to completely cut the center part of the paper ( 32 , 42 ) off main body ( 30 , 40 ) to use main body ( 30 , 40 ) with hole only. Therefore it's quite natural that it takes a lot of time and causes inconvenience to use the sheet. The product in FIG. 4 with cutting line ( 31 ) takes more time than that in FIG. 4 a.
[0011] Moreover, conventional type of sanitary sheet as in FIG. 4 , FIG. 4 a is shorter in width than in length and likely causes fingers to touch the surface of seat when griping both sides of main body ( 30 , 40 ) to place on seat ( 5 ) and is therefore unsanitary. In the case of using the restroom placed in travelling devices in movement (vehicle, airplane, train) the problem is getting worse as user find it so difficult to stand in balance and much inconvenient
[0012] to match main body ( 30 , 40 ) straight to the center of seat.
[0013] Further, conventional type of product described makes old persons, patients and children find it much inconvenient to use.
BRIEF SUMMARY OF THE INVENTION
[0014] The invention aims at providing a sanitary sheet for seated toilet bowl which can be carried for easy use in need all the time and is more sanitary.
[0015] The detailed composition of the present invention features main body ( 10 ) which when placed on seat ( 5 ) with it's width (a) & length (b) forming rectangular has hand grip ( 11 )( 11 a ) protruded to it's both sides, center hole ( 12 ) with at least more than 1 support part ( 13 ) and a sticky resin-coated part ( 14 ) symmetrically forming under limited area of main body ( 10 ) and the center of support part ( 13 ) with cutting line.
[0016] The present invention also features main body ( 10 ) which when placed on seat ( 5 ) with it's width (a) & length (b) forming rectangular has hand grip ( 11 )( 11 a ) protruded to it's both sides, center hole ( 12 ) with at least more than 1 support part ( 13 ) and is folded in small size and inserted into carryable vinyl pack ( 50 ).
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 referring to cross-eyed reference drawing indicating spreaded state of the invention; and
[0018] FIG. 2 referring to plane figure indicating application state of the invention; and
[0019] FIG. 3 referring to reference drawing indicating a state of main body folded in two; and
[0020] FIGS. 4, 4 a referring to reference drawing indicating conventional type of sanitary sheet; and
[0021] FIG. 5 referring to reference drawing indicating a state of the invention put in vinyl pack.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0022] To begin with, the 1st application example of the invention shows main body ( 10 ) which when placed on seat ( 5 ) with it's width (a) & length (b) forming rectangular as FIG. 2 has hand grip ( 11 )( 11 a ) protruded to the direction of both sides of seat ( 5 ), center hole ( 12 ) with at least more than 1 support part ( 13 ) connected to main body ( 10 ). Nextly the 2nd application example of the invention shows sticky resin-coated part ( 14 ) symmetrically forming at both sides of center hole ( 12 ) which is a part of above-mentioned main body ( 10 ).
[0023] In the 2nd application example, sticky resin-coated part ( 14 ) has only to be sticky to an extent that main body ( 10 ) manages to keep it's position on the surface of seat. In this case it might be more convenient in use to have sticky resin-coated part ( 14 ) colored and print a explanatory note on the part of main body ( 10 ) saying “please have sticky resin-coated part contact with seat”.
[0024] Nextly, the width ( 1 ) of hand grip ( 11 )( 11 a ) protruded to both sides when placing main body ( 10 ) on the center of seat needs to be 20 mm minimum and 300 mm maximum. As a result of the application examples of the invention, 50 mm˜100 mm has been found to be proper for the above width ( 1 ). As a major part of the invention, the hand grip ( 11 )( 11 a ) is a technology that has never been applied to conventional type of sanitary sheet. As being extended long to the width direction hand grip makes it quite easier to spread by hand main body ( 10 ) and place in position on seat ( 5 ) and much convenient to use in the restroom placed in travelling devices in movement as well.
[0025] Explaining again, in the 1st application example gripping hand grip ( 11 )( 11 a ), spreading main body ( 10 ) to both sides, and matching the hole ( 12 ) of the invention to the center hole of seat ( 5 ) are needed for use, in the 2nd application example gripping hand grip ( 11 )( 11 a ), spreading main body ( 10 ) to both sides, and matching the hole ( 12 ) of the invention to the center hole of seat ( 5 ) and then slightly pressing with hand grip ( 11 )( 11 a ) facing the ground are followed to have sticky resin-coated part ( 14 ) stick to the surface of seat and place in position afterwards. In the next when a user sits on seat ( 5 ), a support part ( 13 ) formed in the hole ( 12 ) is naturally cut by the weight of the user and therefore no troubles are raised in evacuating excrement and urine.
[0026] As shown above adopting the present invention fingers are kept out of the contact with seat ( 5 ) thus sanitary and it's quite convenient and sanitary to separate the whole main body ( 10 ) from seat ( 5 ) by pulling hand grip ( 11 )( 11 a ) hanging down to both sides of seat ( 5 ). Therefore hand grip ( 11 )( 11 a ) is sanitary, convenient and safe in both using the invention for evacuating and removing the invention from seat ( 5 ) after evacuating and so enables old persons, patients and children to use easily.
[0027] On the other hand, it has been noticed in the test that it is so inconvenient in use to spread main body ( 10 ) by pulling hand grip ( 11 )( 11 a ) and place firm on seat ( 5 ) as specified earlier but without support part ( 13 ) of the hole ( 12 ) because the shape of the hole ( 12 ) is distorted to the direction of both sides or further torn due to the tension imposed. Accordingly it has come to an conclusion that it is more desirable to apply at least more than 1 support part ( 13 ) to the direction of both sides as the invention. By the way, it's better to keep the width of support part ( 13 ) less than 20 mm and is also available to adopt less than 10 mm in 2 lows however these can be freely adjustable. Additionally cutting line can be applied in the center of support part ( 13 ) to make it easier to cut support part ( 13 ) by the weight of users when placing main body ( 10 ) on seat ( 5 ).
[0028] And as described earlier, support part ( 13 ) which has been cut by the weight of a user has it's center area mostly cut and therefore differently from the conventional products the cut length is getting shorter. Accordingly a support part ( 13 ) whose center area keeps out of contact with the water inside seat, makes it available to avoid seeing it soak to the water inside seat and therefore takes away uneasiness owing to unsanity.
[0029] The invention suggested so far can be used for portable purpose after inserting into vinyl pack ( 50 ) by folding main body ( 10 ) in two and repeating the same process until it gets smaller to around 10 cm in width and 5 cm in length as FIG. 3 . Of course, it is quite natural that the invention can be inserted in the box attached to the wall of the restroom to pull out by piece for use and in this case it can be folded in larger size (ie: the width=30 cm, the length=20 cm).
[0030] As for raw material for the invention, it is desirable to select very thin paper which is well soluble in water or water based film, but on the other hand it might also be available to select various types of materials because materials which are not soluble in water can be reused once collected into the trash can. And further it would be much better to apply the anti-bacterial & perfuming treatment to main body ( 10 ) but perfuming treatment is not necessarily required. Additionally it might also be much better to make main body ( 10 ) of the invention in various colors, print on main body ( 10 ) advertisement or public propaganda.
[0031] The invention specified above is contrived to measure the width (a) longer than the length (b) and form support part ( 13 ) in the center hole ( 12 ) and is therefore convenient, safe and sanitary in use compared with conventional type of product. Moreover it can be used conveniently & safely in the restroom placed in travelling devices in movement (vehicle, airplane, train) as well and can also be used promptly and conveniently by anyone including young and old, men and women all alike and patients.
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The present invention is related to portable sanitary sheet for seated toilet bowl that represents distinctive property of portability, advantage of convenience in use and sanity compared with conventional sanitary sheet for seated toilet bowl.
The detailed composition of the present invention features main body ( 10 ) which when placed on seat ( 5 ) with it's width & length forming rectangular, has hand grip ( 11 ) protruded to it's both sides, center hole ( 12 ) with at least more than 1 support part ( 13 ) connected to width direction and sticky resin-coated part ( 14 ) is partially formed in the area between hand grip ( 11 ) and center hole ( 12 ).
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This application is a continuation of U.S. application Ser. No. 4,366, filed Jan. 16, 1987, now abandoned.
BACKGROUND OF THE INVENTION
The present invention relates to apparatuses for handling sheet-like articles, and more particularly, to apparatuses for stacking envelopes into stacks of a predetermined number, packing the stacks into cartons, sealing the cartons and transporting the sealed cartons to an area for loading into shipping containers.
The manufacture of envelopes of the type used to enclose folded documents such as letters, bills, and the like has been automated to the point wherein a single apparatus receives a web unwound from a roll of paper, cuts the web into planks, imprints, folds, and glues the blanks to form envelopes, and arranges the folded and glued envelopes at a discharge station in a horizontal column. An example of such a machine is a rotary reel-fed envelope machine manufactured by Winkler & Dunnebier. Once the envelopes are manufactured by such a machine, they must be separated into groups of a predetermined number, such as 50 or 100 envelopes, loaded into set-up cartons, and the cartons loaded into shipping containers. There also exist devices for separating the envelopes in the horizontal column into groups.
However, presently the groups of envelopes must be manually removed from a horizontal column formed by the envelope machine and placed into the open tops of set-up cartons. The cartons are then transported to a sealing machine and the cartons discharged from the sealing machine must be manually loaded into shipping containers.
In view of the unavoidable hazards present with the manual loading of envelopes into a set-up carton due to the properties of the paper forming the envelopes, and the chance for error resulting from the repeated performance of a manual task, it is desirable to automate this portion of the envelope handling system as well. Suggestions for such automation may be found in several patents.
For example, the Yamada et al. U.S. Pat. No. 4,511,136 discloses a sheet handling device in which a spider feeder feeds sheets traveling horizontally from an upper level conveyor and deposits them into a vertical stack on a lower level conveyor. The apparatus includes reciprocating fingers which are projectable into and out of a sheet stacking zone so that sheets may be collected above the lower level conveyor in order to provide sufficient time for the lower level conveyor to index a completed stack away from the stacking zone. A disadvantage with such a device is that it is incapable of handling freshly folded envelopes which contain air and must be compressed to a height which approximates the thickness of the carton into which they will be packed.
A device for compressing stacks is disclosed in the Sasaki et al U.S. Pat. No. 4,339,119. That patent discloses a sheet stacking apparatus in which reciprocating rods are projected into a stacking zone to catch sheets discharged by an upper level conveyor and accumulate the sheets into a stack. The apparatus includes a "beat member" which presses against the sheets and compresses them against the rods.
A disadvantage with the device disclosed in the Sasaki et al. patent is that it cannot be used with a spider feeder mechanism such as that shown in the Yamada et al. patent. A spider feeder mechanism is an important component in any such system since it provides a mechanism for receiving envelopes or other sheet-like articles from a high level conveyor and depositing them into a vertical stack at a lower level without permitting the envelopes or articles to tumble.
In order to automate that portion of the system in which stacks of articles are packed into set-up cartons, it is necessary to provide a mechanism which removes the articles from a conveyor and feeds them into the carton. Such a device is suggested in the Lister et al. U.S. Pat. No. 4,06,169. That patent discloses an apparatus for packing semi-compressable articles, such as towels, into preformed plastic bags open at one end. The apparatus includes a conveyor which transports the stack of towels to a reciprocating ram which, in turn, transports the stack sidewardly through a pair of gate members and into the preformed bag. The gate members include converging top and side walls for compressing and guiding the stack as it enters the bag.
A disadvantage of such a device is that it cannot be used with other automated equipment of the type which automatically sets up a carton and, subsequent to the carton being loaded with articles, transports the carton to a sealing device. In contrast, the Lister et al. apparatus requires that bags manually be placed in registry with the gate members and, after loading, be manually removed from engagement with the gate members.
Accordingly, there is a need for a system for receiving folded and glued envelopes from a reel-fed envelope machine, stacking the envelopes into vertical stacks into a bucket conveyor, packing the stacks of envelopes into set-up cartons, sealing the cartons, and transporting the sealed cartons to an area for loading in shipping containers. Such a system should be as fully automated at possible and preferably should be capable of use with currently available machines.
SUMMARY OF THE INVENTION
The present invention is a system for receiving envelopes from an envelope machine, arranging the envelopes in vertical stacks of a predetermined number, packing the stacks into set-up cartons, sealing the cartons, and transporting the cartons to an area for loading into a shipping container. The system is fully automated so that manual steps are not required until the cartons are placed into the shipping container.
The system includes a sheet stacking component having a spider feeder for receiving envelopes from the envelope machine and releasing them to fall in a vertical direction into a stacking zone, a pair of pivoting hold back fingers projectable into the stacking zone for interrupting a flow of articles from the blade wheel feeder, a pair of pivoting transfer fingers projectable into the stacking zone below the blade wheel feeder for compressing the height of a completed stack, and pivoting bottom fingers which are capable of moving upwardly to receive the initial sheets of the stack and then pivoting downwardly as the stack grows in height, eventually to the stack onto a bucket conveyor.
Both the hold back fingers and the bottom fingers are counterweighted so that initially they pivot upwardly to receive sheets, then gradually pivot downwardly as the stacks they support grows in size and weight. In contrast, the transfer fingers are pivoted by a double-acting cylinder motor so that they are capable of urging a completed stack supported on the bottom fingers downwardly to place that stack onto a bucket conveyor and, at the same time, compress the stack.
The stacking apparatus also includes a misfeed detector which is positioned above the associated bucket conveyor and slightly downstream of the stacking zone. The misfeed detector includes a pair of L-shaped members attached to a transverse axle pivotally supported on a frame attached to the conveyor. Should a stack be misfed onto a bucket, the resulting increase in height will cause the stack to contact one or both of the L-shaped members causing the axle to pivot and trip a sensor which sends a signal to a control to stop the loading operation.
In operation, the spider feeder initially deposits envelopes into a first vertical stack upon the bottom fingers which have been pivoted upwardly by the counterweight. After a predetermined number of envelopes have collected on the bottom fingers, the hold back fingers project into the stacking zone and interrupt the flow of envelopes to the bottom fingers so that envelopes begin collecting upon the hold back fingers in a second stack. At the same time, the transfer fingers project into the stacking zone below the hold back fingers and are urged downwardly to lower the first stack onto a bucket conveyor. The conveyor indexes forwardly to remove the loaded bucket from the stacking zone and replace it with an empty bucket for the second stack.
At this time, the double-acting cylinder motor pivots the transfer fingers upwardly, allowing the bottom fingers to pivot upwardly in response to the counterweight, and the transfer and hold back fingers retract from the stacking zone allowing the partially collected second stack to fall upon the bottom fingers, and the cycle begins again. The advantage of this component of the system is that it receives envelopes from an envelope machine in a continuous manner, collects them into discrete, vertical stacks, partially compresses the stacks, and loads the stacks onto a bucket conveyor, all without interrupting the continuous operation of the envelope machine.
The envelope packing component of the system includes a ram for displacing a stack of envelopes from the conveyor toward a set-up carton in a packing zone, a chute for conveying a stack from the bucket, and a pair of gate members for conveying the stack from the chute to the interior of the carton. The ram is connected to a double-acting cylinder motor and the gate members are pivoted by rotary actuators between a loading or open position, in which they extend into the carton interior, and a closed position. The walls of the chute and gate members converge so that a stack is compressed and aligned as it passes from the conveyor to the set-up carton.
The cartons are set-up by a carton machine of known design which also includes a sealing component that folds the end flaps of the cartons, seals the cartons and discharges the sealed cartons to be conveyed to the carton packing area. The carton machine includes front and rear tucker bars which have been modified to maintain the bottom panel end flaps of a loaded carton closed prior to the time the carton enters the sealing apparatus, without deflecting the top panel end flaps of the carton. The rear tucker bar is actuated first so that it provides a backstop for preventing the envelopes from protruding from the opposite, open end of the carton. The front tucker bar is actuated after the ram is withdrawn from the carton to close the front bottom panel end flap of the carton.
At the beginning of the operation sequence for the envelope packing apparatus, the carton machine sets up a folded carton blank in a packing zone so that its front open end is in registry with the gate members, and the gate members pivot to a packing configuration in which their outer ends extend within the interior of the carton. The ram then displaces a stack sidewardly from a bucket on the conveyor through the chute, the pivoted gate members, and into the interior of the set-up carton. The ram withdraws from the carton and, as it clears the gate members, the gate members pivot to a position in which the members are withdrawn from the carton interior and are aligned parallel to the direction of travel of the carton. The front tucker closes the bottom panel end flap, and the packed carton is transported from the packing zone to the sealing machine.
Another component of the system is a carton transporting apparatus which is designed to be used in combination with a sealing apparatus of the type having a top discharge in which the packed cartons are lying on a side panel. The transporting apparatus includes a helical channel which receives the cartons from the sealing apparatus and rotates the cartons to an upright position. A reciprocating plate positioned above the sealing apparatus urges cartons emerging from the sealing apparatus along the helical channel.
The terminal portion of the channel is supported in a horizontal surface, such as work table, and includes a reciprocating platen. The reciprocating platen urges the cartons deposited on the table in a direction perpendicular to the direction of travel along the channel so that the cartons form a horizontal column in which side pannels of the cartons abut.
In a preferred embodiment, the helical channel includes a raised portion adjacent to the terminal portion of the channel which contacts the bottom panels of the cartons and prevents more than a single carton from being deposited upon the horizontal table at a time.
A specific carton has been designed for use with this envelope handling system. This carton includes a full bottom panel, front and rear side panels, and two partially-overlapping partial top panels connected to the side panels at score lines. Only one of the partial top panels is provided with a pair of opposing end flaps; the other partial top panel is "flapless."
In this configuration, gaps are formed between the end flaps of the partial top panel and the end flaps of the side panel adjacent to the flapless partial top panel When used in the carton handling appartus comprising the envelope packing component of the envelope handling system, the carton is set up such that the top panels face downstream towards the sealing apparatus. When the tucker bars are actuated, they are able to contact and close the upstream bottom panel end flaps, extend across the open ends of the carton, through the gaps below the top panel end flaps, and terminate beyond the top panel of the carton.
This allows the ends of the cartons to be completely closed to prevent envelopes within the interior from escaping, and forms a continuous guide which abuts the flap closing rails of the sealing apparatus so that the likelihood of the bottom panel end flaps opening prior to the carton entering the sealing apparatus is minimized.
Another aspect of the carton is that it is designed so that the envelopes are accessible to a user from both and end of the carton and the top. The partial end flaps are attached to the associated partial top panels by score lines which include perforations which facilitate separation of the flaps from the panel. Accordingly, the top of the set-up carton may be opened by separating the partial panels from each other, then separating the partial top panel from each other, then separating the inner partial top panel from its respective side panels. To make this top opening resealable, the outer partial top panel is provided with a tab and the inner partial top panel is provided with a slit shaped to receive the tab.
Accordingly, it is an object of the present invention to provide an envelope handling system in which envelopes are removed from a high level conveyor and released to fall into a vertical stack with a minimum of tumbling; an envelope handling system in which envelopes are taken from a continuously operating envelope machine and stacked in stacks of predetermined sized on a bucket conveyor without interrupting the operation of the envelope machine; an envelope handling system which automatically removes stacks of envelopes from a bucket conveyor and packs the stacks into set-up cartons; an envelope handling system in which sealed cartons are transported to a loading area and arranged in a horizontal column to facilitate packing in shipping containers; a carton for use with an envelope handling system which facilitates the use of flap closing components; and an envelope handling system in which the number of manual operations required to stack envelopes, place the envelopes in cartons, and load the cartons in shipping containers is minimized.
Other objects and advantages of the present invention will be apparent from the following description, the accompanying drawings, and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic, perspective view of a preferred embodiment of the envelope handling system of the present invention;
FIG. 2 is an exploded, perspective view of the envelope stacking component of the system of FIG. 1;
FIG. 3 is a perspective, partially exploded view of a detail of the stacking component of FIG. 2, showing the hold fingers, transfer fingers, and bottom fingers;
FIG. 4 is a detail showing the double-acting cylinder motor for actuating the transfer fingers shown in FIG. 3;
FIGS. 5, 6, 7, and 8 each are schematic side elevations of the sheet stacking component shown in FIG. 2, and progressively show the continuous removal of envelopes from the spider feeder and the loading of the envelopes onto an associated bucket conveyor;
FIGS. 9, 10, 11 and 12 are each details showing, in perspective, the envelope packing component of the system of FIG. 1, and show, in sequence, the operation of packing a stack of envelopes into a set-up carton;
FIG. 13 is a perspective view showing the carton conveying component of FIG. 1;
FIG. 1 is a diagram of the computer control of the embodiment of FIG. 1;
FIG. 15 is a top plan view of a box blank used to form a carton of the type shown in FIG. 1;
FIGS. 16, 17, 18, and 19 together show the sequence in which the end flaps of the carton of FIG. 1 are folded; and
FIG. 20 is a perspective view of an intermediate folded blank of, the carton shown in FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
As shown in FIG. 1, the envelope handling system of the present invention includes a sheet stacking component, generally designated 30, an envelope packing component 32, and a carton transporting apparatus 34. An endless bucket conveyor, generally designated 36, extends between the sheet stacking component 30 and the envelope packing apparatus 32.
The conveyor 36 includes a flexible belt 38 which supports a plurality of individual buckets 40. Each bucket 40 includes front and rear pairs of legs 42, 44, and a central, U-shaped channel 46 for supporting a stack 48 of envelopes 50.
Sheet Stacking Apparatus
As shown in FIGS. 1, 2, and 3, the sheet stacking component includes a spider feeder, generally designated 52, hold back fingers 54, transfer fingers 56, and bottom fingers 58. The spider feeder 52 comprises three disks 60, 62, 64 which are spaced from each other and mounted on a common axle 66. Each of the disks 60-64 includes a plurality of arcuate, tapering arms 68 spaced about its periphery and separated from each other to form slots 70 shaped to receive envelopes 50.
The spider feeder 52 is positioned to receive envelopes from the output conveyor of an envelope machine (not shown). A typical machine which may be used with the system of the present invention is a Helios 399 G/GS rotary reel-fed envelope machine, manufactured by Winkler & Dunnebier, GmbH & Co. KG, Neuwied, West Germany.
The hold back fingers 54, transfer fingers 56 and bottom fingers 58 are positioned below and rearwardly of the spider feeder 52. As shown in FIGS. 2 and 3, the hold back fingers 54 include a U-shaped mounting bracket 72, a forwardly extending strut 74, and a pair of mounting channels 76, 78 attached to opposite sides of the strut. The strut 74 includes a boss 80 at its base adjacent to the bracket 72, and the boss receives a mounting block 82. Left and right double-acting cylinder motors 84, 86, respectively, are attached to the mounting block 82 and includes rods 88, 90 attached to slide blocks 92, 94.
The slide blocks 92, 94 are seated in longitudinal slots 96, 98 formed in the mounting channel 76, 78, respectively, and receive the rearward ends of left and right hold back pins 100, 102. The hold back pins 100, 102 extend through holes formed in forward bearing blocks 104, 106 and are seated, when retracted, within rearward bearing blocks 108, 110, attached to opposite ends of longitudinal channels 96, 98, respectively.
Actuation of the cylinder motors 84, 86 such that the rods 88, 90 extend outwardly causes the slide blocks 92, 94 to travel within the channels 96, 98 and displace the pins 100, 102 outwardly from the mounting channels 76, 78. The longitudinal slots 96, 98 are sized such that displacement of the slide blocks 92, 94 to the rear of the slots causes the rods 100, 102 to retract completely within the mounting channels 76, 78.
The bracket 72 includes journal bearing 111 forming a transverse bore 112 which is journaled onto an axle 114. The axle 114 is attached to a frame 116 which, in turn, is mounted on and extends rearwardly from the conveyor 36. The hold back fingers 54 are centered on the axle by means of a clevis 118 that receives a shaft collar 120 fixed to an axle 114. The clevis 118 includes a transverse passage (not shown) which forms a part of the transverse bore 112 receiving the axle 114.
An adjustable counterweight 122 is mounted on a rod 124 which is attached to a mounting block 126 fastened to the bracket 72 by machine screws 128. The counterweight 122 is adjusted along the rod 124 such that its weight pivots the mounting channels 76, 78 about axle 114 upwardly toward the spider feeder 52.
The transfer fingers 156 include left and right mounting bracktes 130, 132, respectively, which are attached to left and right mounting channels 134, 136. The mounting channels 134, 136 are separated by struts 138, 140 and include longitudinal slots 142, 143.
Double-acting cylinder motors 144, 146 are mounted on the mounting brackets 130, 132, respectively, and include rods 148, 150 attached to the upper portions of slide blocks 152, 154. The slide blocks 152, 154 ride in the longitudinal slots 142, 143 and are attached to transfer pins 156, 158, respectively. The pins 156, 158 are journaled into forward bearing blocks mounted on the forward ends of the channel 134, 136, 160, 162, and, when retracted, engage rearward bearing blocks 164, 166, placed at the rearward ends of the longitudinal slots 142, 143, respectively. The mounting brackets 130, 132 include journal bearings 168, 170 which receive the axle 114.
Mounting channel 146 includes a knuckle 172 which is attached to the clevis 174 of a double-acting cylinder motor 176 The cylinder motor 176 is pivotally attached to a clevis 178 that, in turn, is attached to a downwardly-extending bar 180. The bar 180 is connected to a transverse boss 182 forming and intergral part of the frame 116.
As best shown in FIG. 4, the clevis 174 includes a tubular portion 184 having a pair of longitudinal slots formed therein (only one of which is shown), and an annular shoulder 188. A cylindrical rod 190 telescopes into the tubular member 184 and includes a cross pin 192 which is captured within and slides along the slots 186. The rod 190 terminates at its lower end in a disk-shaped spring seat 194 that includes a mounting nut 196 receiving the end of the cylinder rod 198 of the cylinder motor 176. A coiled spring 200 is captured between the annular shoulder 188 and spring seat 194, which are spaced apart sufficiently to allow the spring to urge the rod 190 out of the tubular member 184 and drive the pin 192 against the bottom of the seat 192.
The bottom fingers 58 include a U-shaped yoke 202 and three finger elements 204, 206, 208. The finger elements 204-208 include rectangular bars 210, 212, 214 which are attached at their bases to the yoke 202 and terminate in finger plates 216, 218, 220, respectively. A crossbar 222 extends transversely of and is attached to the bars 210-214, and includes a resilient boss 224 which is positioned to contact the underside of strut 138 of the transfer fingers 56.
The yoke 202 includes journal bearings 226, 228 which are sized to receive the axle 114, and are carried on upright mounting brackets 230, 232 that are spaced apart sufficiently to receive the transfer fingers therebetween. A counterweight 234 is adjustably mounted on a rod 236 extending rearwardly from the yoke 202. The forward tip of the rod 236 is fixed to a boss 238 mounted on the underside of the finger element 206. The yoke 202 is centered on the axle 114 by shaft collars 240, 242.
The conveyor 36 on which the sheet stacking apparatus is mounted includes a pair of inverted, L-shaped side channels 244, 246 which open inward and face the buckets 40. The stacks 48 of envelopes 50 (see FIG. 1) travel within the channels and are maintained in their compressed configuration by the upper horizontal surfaces 247 of the channels 244, 246 as they are conveyed toward the envelope packing apparatus 32. A pair of separator bars 248, 250 are mounted on the upper surfaces of the side channels 244, 246 and, as will be explained, operate to remove envelopes 50 from the slots 70 of the spider 52. Preferably, the separator bars 248, 250 are arcuate in shape, having as centers of curvature the axle 114.
The conveyor 36 includes a misfeed detector 252 which includes upright members 254, 256 attached to the side channels 244, 246, respectively, which in turn support a transverse axle 258. Attached to the transverse axle are a pair of L-shaped members 260, 262 that include vertical components 264, 266, respectively. Vertical component 266 includes a detent (not shown) which engages a dimple 267 in upright member 256 when the components are aligned with the members. The detent provides a "break away" action for the L-shaped members.
Vertical component 266 includes a trip plate 268 which is positioned adjacent to a proximity switch 270 mounted on the upright member 256. A stack of envelopes indexed forwardly in a bucket 40 which includes envelopes above the side channels 244, 246 will impact the L-shaped members 260, 262 and cause the axle 258 to rotate, removing the trip plate 268 from the immediate vicinity of the proximity switch 270, thereby generating a signal indicating that a jam or a misfeed has occured.
The operation of the sheet stacking apparatus is as follows. As shown in FIG. 5, envelopes 50 are conveyed from an upper level conveyor (not shown) to a stacking zone 272 by the spider feeder 52, where they contact the separator bars 248, 250 and are removed from the spider feeder disks 60, 62, 64 (see FIG. 1). At this time, the hold back pins 100, 102 and transfer pins 156, 158 have been withdrawn within their respective mounting channels 76, 78, 134, 136, and the cylinder motor 176 has been actuated to pivot the transfer fingers 56 to an upward position. This allows the bottom fingers 58 to pivot upwardly as well in response to the force exerted by the counterweight 234.
As the envelopes 50 fall from the spider feeder 52, they collect in a first stack 48 upon the bottom fingers 58. By permitting the bottom fingers 58 to pivot upwardly as shown in FIG. 5, the distance the envelopes 50 fall before collecting into the stack 48 is minimized, thereby minimizing the likelihood of a misaligned stack. The counterweight 234 is adjusted such that the bottom fingers 58 pivot downwardly in response to the increasing weight of the first stack 48 collecting upon it.
As the envelopes 50 slide out of slots 70 of the spider feeder 52, they exert a downward force on the hold back and transfer fingers 54, 56, respectively. Hold back fingers 54 pivot downwardly in response to this force, while the spring-loaded clevis 174 (FIG. 4) allows the transfer fingers 56 to pivot slightly downwardly.
As shown in FIG. 6, when a predetermined number of envelopes 50 have been collected upon the bottom fingers 58, the cylinder motors 84, 86 of the hold back fingers 54 and the cylinder motors 144, 146 of the transfer fingers 56 are actuated to displace their respective pins 100, 102, 156, 158 outwardly (see FIG. 2). Consequently, successive envelopes 50' leaving the spider feeder collect upon the hold back pins 100, 102 of the hold back fingers 54 in a second stack 48'.
As shown in FIG. 7, the cylinder motor 176 is actuated to pivot the transfer fingers 56 downwardly, which causes the transfer pins 156, 158 to bear down against the topmost envelope of the completed first stack 48. This downward force compresses the stack and urges the bottom fingers 58 downwardly to place the stack within the bucket 40 of the conveyor 36. The finger plates 216, 218, 220 (see FIG. 2) are spaced such that the rear legs 44 of the bucket extend between them. Once the stack 48 has been lowered so that it rests upon the channel 46, the conveyor 36 is actuated to index the loaded bucket forwardly, thereby removing that bucket from the bottom fingers 58 in the stacking zone 272 and presenting an empty bucket 40' into the stacking zone, as shown in FIG. 8.
At this time, the cylinder motor 176 is actuated to pivot the transfer fingers 156 upwardly, which allows the bottom fingers 58, now empty, to rise to the position shown in FIG. 5. At that time, all four pins 100, 102, 156, 158 are retracted to allow the stack 50', which had been collecting upon the hold back pins 100, 102, to fall upon the fingers 216, 218, 220 of the bottom fingers 58.
It should be noted that the counterweight 122 of the hold back fingers 54 is adjusted such that the hold back pins 100, 102 are pivoted downwardly under the increasing weight of the collected stack 50'. Consequently, the distance that a released envelope must fall is maintained at a minimum and is consistent for every envelope collected into the stack 50'.
Envelope Packing Apparatus
As shown in FIGS. 1 and 9, the envelope packing apparatus 32 includes a ram 274 consisting of a double-acting cylinder motor 276 having a C-shaped bracket 278 attached to the end of its rod 280. A chute 282 is positioned adjacent to the conveyor 36 opposite the ram 276 and includes converging top, bottom and side walls 284, 286, 288, 290, respectively, which act to compress and align a stack 50 of envelopes passing through it.
A pair of gate members 292, 294 are positioned on a side of the chute 282 opposite the conveyor 36 and are attached to vertical pivot shafts 296, 298 which are positioned by rotary actuators (not shown). The gate members 292, 294, each comprise a L-shaped channel having converging top and bottom walls, and a beveled outer end 299 to provide clearance when the members pivot between the open or packing position shown in FIG. 10, and the closed position of FIG. 9. The gate members 292, 294 are positioned adjacent to a carton machine, generally designated 300. The carton machine 300 is positioned to pull cartons 302 from a magazine 304 of carton blanks 306 and set-up the cartons such that its open end 308 is in registry with the gate members 292, 294. An example of such a carton machine 300 is the Econoseal E-System, manufactured by Econocorp, Inc., Needham Heights, Mass.
The carton machine 300 includes a horizontal ram plate 310 which contacts and sets up the cartons 302, a double-acting cylinder motor 312 for displacing the ram plate in a downstream direction, a series of rails, generally designated 314, for closing the end flaps of the carton 302, and a sealing and cooling component, generally designated 316.
The carton machine 300 has been modified to include front and rear tucker bars 318, 320, which are attached to double-acting cylinder motors 322, 324, respectively. Each of the tucker bars 318, 320 includes a side plate 326 terminating in a rounded finger 328. The fingers 328 of the tucker bars 318, 320 are shaped to extend through gaps 330, 332 formed between the front and rear partial end flaps 334, 336, and the side flaps 338, 340 (see also FIG. 19).
The operation of the envelope packing apparatus is shown sequentially in FIGS. 9, 10, 11 and 12. After the carton machine 300 has set-up a blank 306 in a packing zone 341 (see also FIG. 1) to form a carton 302 with front and rear open ends 308, 342, cylinder motor 324 is actuated to displace rear tucker bar 320 forward, thereby closing rear bottom end flap 334 and blocking the rear open end 342 of the carton. The conveyor 36 is actuated to bring a bucket 40 loaded with a stack 48 of envelopes into registry with the chute 282.
As shown in FIG. 10, gate members 292, 294 are pivoted about shafts 296, 298 such that their forward portions 299 enter the interior 346 of the carton 302, and the gate members are aligned with the chute 282 and are perpendicular to a direction of travel of the carton, indicated by arrow A in FIG. 1.
Cylinder motor 276 of ram 274 is actuated to extend rod 280 so that C-bracket 278 displaces stack 50 from between the front and rear legs 42, 44 of the bucket 40 sidewardly through and gate members 292, 294 , each of which compresses and aligns the stack, and into the interior 346 of the carton 302. The presence of the rear tucker bar 326 prevents the envelopes within the stack 48 from exiting the rear open end 342.
As shown in FIG. 11, the cylinder motor 276 is actuated to withdraw the bracket 278 to a position adjacent to the conveyor 36 opposite the chute 282, which provides clearance for the conveyor to index a next bucket 40 adjacent to the packing zone 341. At this time, the gate members 292, 294 are pivoted out of the interior 346 of the carton 302, thereby providing clearance for the carton to be displaced from the packing zone 341, in a downstream direction relative to the carton machine 300 (FIG. 1).
Rotation of the gate members 292, 294 also provide clearance for the front tucker bar 318 to be indexed forwardly to close the front bottom end flap 348. It should be noted that, at this time, the fingers 328 of the front and rear tucker bars 318, 320 protrude through the gaps 330, 332 present in the carton 302, so that there is a substantially continuous rail formed with the rails 314 of the sealing component 316 (FIG. 1) which prevents the front and rear bottom end flaps 348, 344 from springing open as the carton is displaced from the packing zone 341.
As shown in FIG. 12, the double-acting cylinder motor 312 is actuated to displace the ram plate 310 in a downstream direction from the packing zone 341 toward the sealing component 316, thereby displacing the loaded carton 302 along support rails 350 of the carton machine 300. After the cylinder 312 withdraws the ram plate 310 to its original position shown in FIG. 1, the cycle may begin again.
Carton Transporting Apparatus
As shown in FIGS. 1 and 13, the carton transporting apparatus 34 is used in combination with the carton sealing component 316 which receives loaded cartons at a lower level seals the end flaps of the carton, allows the adhesive to cool, and discharges sealed cartons 302' vertically. The transporting apparatus includes a pushing element 350, a helical channel 352, and a queuing component 354. The pushing element 350 includes a support frame 356, a double-acting cylinder motor 358, a longitudinal rod 360 and a pusher plate 362. The pusher plate includes a mounting bracket 364 which is journaled onto the longitudinal rod and is connected to the rod 366 of the cylinder 358. The pushing element 350 is oriented such that actuation of the cylinder 358 causes the plate 362 to reciprocate in a direction that is aligned with the direction of travel of the channel 352.
The channel 352 includes a helical major wall 368 that is substantially horizontal at an end adjacent to the sealing component 316 and positioned to receive a sealed carton 302', and is substantially vertical adjacent to the queuing component 354. The major wall 368 is attached to a minor wall 370 which is substantially vertical adjacent to the discharge of the sealing component 316, and is substantially horizontal adjacent to the queuing component 354 The minor wall 370 includes an upwardly extending portion 372 which is positioned adjacent to the queuing component 354.
The queuing component 354 includes a double-acting cylinder motor 374 having a rod 376 that is connected to a horizontally-extending platen 378. The platen 378 is positioned within a terminal cut-out 380 formed in the major wall 368. The cylinder 374 is positioned adjacent to a support table 382 which forms a part of a container loading station, generally designated 384 (see FIG. 1). Preferably, the cylinder motor 374 is connected to the pneumatic system of the sealing component 316, as is the cylinder motor 358. Cylinder motors 374, 558 cycle simultaneously.
The operation of the carton transporting apparatus 34 is as follows. Sealed cartons 302' are discharged upwardly from the sealing component 316. As a carton 302' is raised to an elevation corresponding to the horizontal component of the major wall 368, and the double-acting cylinder motor 358 is actuated to draw the cylinder rod 366 inwardly, thereby displacing the pushing plate 362 toward the channel 352. This moves the carton onto the channel 352.
This process is repeated for successive sealed cartons, eventually loading the channel 352 with cartons 302' positioned end-to-end. The cartons are prevented from sliding all at once onto the support table 382 by the upwardly extending portion 372, which is positioned to prevent cartons from sliding freely thereover and allow only a single carton to slide onto the table at one time. As each carton is deposited on the table 382 in front of the queuing component 354, the cylinder motor 374 is actuated to displace the platen 378 outwardly, thereby moving the carton 302' in a direction perpendicular to its direction of travel along the channel 352.
Successive displacement of cartons deposited on the table forms a horizontal column of cartons 302' which are arranged such that their side panels abut each other. The cartons may then be loaded into shipping containers 386.
Computer Control
As shown schematically in FIG. 14, the sheet handling system of the present invention is operated automatically by a computer control 386. In the preferred embodiment, the control is a GE Series I programmable conroller manufactured by General Electric Corporation. As shown in FIGS. 1 and 2, an electric eye 388 is associated with the spider feeder 52 and detects the presence of envelopes 50 within the slots 70. The signals generated by the electric eye enable the control 386 to count the number of envelopes entering the stacking zone 272 (see FIG. 5) to enable the control to actuate the hold back fingers 54 to project into the stacking zone 272 to begin a new stack.
As shown in FIGS. 2 and 3, the mounting channel 136 of the transfer fingers 58 includes a trip-plate 390 which is positioned adjacent to a proximity switch 392 mounted on the frame 116. When the transfer fingers 56 have been lowered by double-acting cylinder 176 to the point where the proximity switch is tripped 40, the control 386 actuates the conveyor 36 to index the bucket, now loaded with a stack 48, forwardly out of the stacking zone 272.
As explained previously, a proximity switch 270 is tripped when a misfeed occures in which a stack of envelopes is lofted such that the L-shaped members 260, 262 are pivoted about the axle 258. This signal causes the control 386 to stop the stacking process.
A photo cell 394 is positioned above the conveyor and slightly outward of it for detecting the presence of a stack 48 adjacent to the double-acting cylinder 276. When a stack 48 actuates the photocell 394, the control 386 actuates the double-acting cylinder 276 to displace the stack through the chute 282 and into the carton 302 (see FIG. 1).
A photocell 396 is positioned above the gate members 292, 294, and detects the return stroke of the double-acting cylinder 276. When photocell 396 is actuated, the control 386 activates the rotary actuators to pivot the gate members 292, 294 to a closed position shown in FIG. 11. Limit switches 398, 400 are mounted internally of the double-acting cylinder motor 276, and signal the control 386 when the rod 280 has reached the limits of its stroke. When the rod 280 is fully extended, the control 386 is signalled to begin the return stroke. When the rod 280 is fully retracted, the control 386 is signalled to index the conveyor 36.
Although the carton machine 300 is of a type known in the art, in the preferred embodiment it has been modified to include a photocell 402 which detects the presence of a set-up carton 302 adjacent to the ram plate 310 (see FIG. 1). The presence of a set-up carton 302 as shown in FIG. 1 signals the control 386 to actuate the ram 274 to displace the stack 48 of envelopes into the set-up carton 302.
Carton
As shown in FIG. 15, the carton used with the envelope handling system previously described is made from a blank 404. Blank 404 includes a bottom panel 406, side panels 408, 410, and inner and outer partial top panels 412, 414 respectively. The side panels 408, 410 are connected to the bottom panel 406 along longitudinal score lines 416, 418, respectively. Partial top panel 412 is connected to side panel 408 at a longitudinal score line 420, and partial top panel 414 is connected to side panel 410 at a longitudinal score line 422 extending alongs its length. Partial top panel 412 includes a slit 424 which is shaped to receive a tab 426 formed in partial top panel 414 when the carton 302 (FIG. 16) is opened and resealed.
Bottom panel 406 includes front and rear end flaps 428, 430 connected at transverse score lines 432, 434, respectively. Side panel 408 includes front and rear end flaps 436, 438 connected by transverse perforated score lines 440, 442, respectively. Side panel 410 includes front and rear end flaps 338, 340 connected by transverse perforated score lines 444, 446, respectivley. In the preferred embodiment, flaps 338, 340 are slightly shorter in length than flaps 436, 438, to provide clearance with side panel 408 when folded as shown in FIG. 18.
Partial top panel 412 includes front and rear end flaps 334, 336, connected by transverse perforated score lines 448, 450, respectively. In contrast, partial top panel 414 is flapless and includes front and rear transverse edges 452, 454, respectively.
The intermediate folded blank is shown in FIG. 20. Side panel 408 is folded at score line 416 to overlie bottom panel 406 and side panel 410. Outer partial top panel 414 is folded at score line 422 to partially overlap inner partial top panel 412. In the resulting intermediate blank 306, gaps 330, 332 are formed between top panel ends flaps 334, 336, and ends flaps 338, 340 of side panel 310.
As shown in FIG. 16, the set-up carton 302 is rectangular in transverse cross-section and is positioned on the carton machine 300 (see FIG. 1) such that the gaps 330, 332, face in a downstream direction and extend substantially vertically.
As shown in FIGS. 16, 17, 18, and 19, the end flaps of the carton 302 are folded in the following order. For purposes of expediency, FIGS. 17-19 illustrate only the front portion of the carton 302, it being understood that the appearance and order of flap closing for the rear portion is identical. As shown in FIG. 1, the bottom panel end flaps 428, 430 are first closed by the front and rear tucker bars 318, 320 of the carton machine 300. The fingers 328 of the tucker bar extend to a point adjacent to the folding rails 314 of the carton machine, so that as the carton 302 is urged into that portion of the machine, the bottom panel end flaps 428, 430 remain closed. The folding rails 314 of the sealing component 316 next fold the top panel end flaps 334, 336. The sealing component 316 then proceeds to fold side panel end flaps 338, 340, then end flaps 436, 438. The sealing machine seals the flaps with an appropriate adhesive. As the sealed cartons 302' are indexed upwardly within the sealing machine 316 the glue sealing the flaps has an opportunity to cool and harden.
The advantage of the specific design of the box blank 404, intermediate folded blank 306, and set-up carton 302 is that the top panel end flaps 334, 336 form gaps 330, 332 with the side panel end flaps 340 which allow the fingers 328 of the tucker bars 318, 320 to extend through and beyond the set-up carton 302 to a point immediately adjacent to the downstream folding rails 314 of the sealing component 316. It is preferable that only the downstream end flaps 334, 336 form a gap with the side panel end flaps 338, 340 since the end flaps 428, 430 must be contacted by the tucker bars and form an appropriate closure for the carton 302.
A user of the carton 302 may gain recess to the envelopes through the partial top panels. First, outer partial top panels 414 is separated from inner partial top panels 412 and pivoted about score line 422. Next, inner partial top panel 412 is separated from flaps 334, 336 at perforated score lines 448, 450 and pivoted about score line 420 away from the carton 302 to expose the contents of the carton. The carton may be resealed by folding partial top flap 414 over partial top flap 312 and tucking tab 426 into slit 424.
While the form of apparatus herein described constitutes a preferred embodiment of this invention, it is to be understood that the invention is not limited to this precise form of apparatus, and that changes may be made therein without departing from the scope of the invention.
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An envelope handling system for removing envelopes from an upper level conveyor, placing them in stacks on a lower level bucket conveyor, removing the stacks from the bucket conveyor and side-loading them into cartons, and sealing the cartons, conveying the cartons to a packing area, and forming the cartons into a horizontal column for placement into shipping containers. The system includes a spider feeder for removing the envelopes from an upper level conveyor and discharing them downwardly in a vertical direction, pivoting bottom fingers for receiving envelopes from the feeder and collecting them into a stack, hold back fingers for intercepting envelopes in a second stack above the bottom fingers, and transfer fingers for compressing a stack collected on the bottom fingers and urging the bottom fingers downwardly to place the stack onto the conveyor. The carton A reciprocating ram urges a stack sidewardly from a bucket, a chute and pivoting gate members direct a stack into a set-up carton and compress the stack as it passes therethrough. Reciprocating tucker bars close upstream end flaps of the carton. A helical conveyor channel receives cartons from a sealing machine, orients the cartons to an upright position and deposits the cartons onto a horizontal surface. A reciprocating plate urges the cartons along a channel and a reciprocating plate urges the cartons sidewardly to form the horizontal column.
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The present invention pertains to the art of sheet metal roofing assemblies, and particularly to the structure of a lap joint between adjoining sheet metal roofing panels.
BACKGROUND OF THE INVENTION
Sheet metal panels are commonly used as components of commercial roofing structures. An assembly of sheet metal panels is fastened together to form a generally flat cover over a roof substrate which may comprise a framework of wood or metal joists, a plywood surface supported on an underlying framework of joists, poured concrete, or the like. Various types of joints are used to fasten the panels into a strong and watertight cover assembly. Standing seam joints comprise a folded connection between adjacent panels which extends vertically upwardly from the panels along the length of the joint. A novel standing seam joint structure is the subject of another patent application of the present inventor. This application pertains to a lap joint which has a primarily horizontal configuration across the joined panels.
A common lap joint structure is that used to assemble the traditional flat lock roof. A flat lock roof panel has edge sections folded back over the main section of the panel to form hemmed edges. The hems are left slightly open to permit hooked engagement with the oppositely facing hem of an adjacent panel to form a joint defined by the overlapping hem sections. The joints are soldered to provide a watertight seal. Although used consistently for many years, this type of joint structure has several problems. For example, the engaged hem sections, when considered in cross section, comprise four layers of sheet metal material which must be thoroughly heated from above to create conditions wherein the molten solder will be drawn into the joint sufficiently to provide a reliable watertight seal. The soldering portion of the assembly process is thus time consuming and skillfully demanding. Soldering problems also arise where the sheet metal panels are nailed or otherwise fastened to the underlying substrate since those punctures through the sheet metal material must be sealed against water. Furthermore, sealing the joints with solder results in a rigid connection between adjoining panels which cannot yield to the strenuous forces induced by thermal expansion and contraction and which may in turn cause buckling of the sheet metal material or breakage of the soldered seal.
Another disadvantage of the traditional flat lock roof joint structure is the difficulty of assembling the panels in an orderly layout along planned lines without accumulating substantial deviations between successively joined edges. This problem is best overcome by assembling a staggered array of panels having a practical size limit of 20×28 inches. As the number of joints multiplies with the number of panels, construction of a flat lock roof of any substantial size can become a disproportionately demanding portion of a commercial construction project.
Another type of lap joint structure for a sheet metal roofing assembly may be referred to as a flat lock joint with cleats. Such a joint comprises a row of cleats extending along the length of the joint. The cleats are each nailed or otherwise securely anchored to the roof substrate and include cleat hems interposed between the interlocking hem sections of the sheet metal panels to hold the panels down against the roof substrate. Since the panels are not nailed directly to the underlying substrate but instead are anchored thereto by means of the cleat, this joint structure is superior to the above-described flat lock joint structure which is prone to leak where the anchoring nails perforate the sheet metal panels. However, the overlapping hem sections must still be soldered, and positioning of the cleat hems between the interlocking panel hems brings the number of sheet metal layers which must be thoroughly heated to a total of six. The skill, time, and consequent cost of providing a water tight soldered seal along the entire length of the joint are thereby greatly increased. Furthermore, the panels and cleats are rigidly interconnected through the joint structure and cannot yield to the stress imposed by thermal expansion and contraction of the sheet metal material.
A third type of lap joint structure for a sheet metal roofing assembly consists merely of overlapping panel edges riveted and soldered together. Although this is the strongest type of joint, it, too, suffers from several disadvantages. A simple overlap between panel edges does not accommodate the use of cleats to anchor the panel assembly to the roof substrate, whereby the panels must be anchored by means of nails or other fasteners perforating the panels. Nails not only present an unsightly appearance with frequent damage from hammer blows to the surrounding sheet metal material, but also cause imperfect perforations which are difficult to seal with solder, and their use may be prohibitively labor intensive on a large project. Sheet metal screws are likely to be used more commonly than nails since they may be quickly and easily inserted by means of an automatic driving tool. However, the drilling action of the automatic tool tends to shred the sheet metal material to raise a burr at each perforation which both disrupts the level contour of the panels and increases the difficulty of sealing the perforation with solder. Again, the rigidly anchored assembly cannot accommodate thermally induced movement of the panels.
Methods of constructing known joints for sheet metal roofing assemblies are correspondingly troublesome. Great difficulty is experienced in maintaining adjacent sheets in alignment with a planned layout.
The prior art is thus seen to fail to provide a joint structure for a sheet metal roofing assembly which can easily be soldered without a great deal of time and skill, which accommodates thermally induced movement of the sheet metal panels, and which can be securely anchored to the roof substrate without unsightly and leak-prone perforations through the panels.
SUMMARY OF THE INVENTION
The present invention overcomes the above-described disadvantages and others and provides a lap joint structure for a sheet metal roofing assembly which securely anchors the sheet metal panels to the roof substrate with provision for thermally induced movements of the panels and without leaks, as well as an efficient and simplified method of installing the joint structure.
In accordance with a principal feature of the invention, there is provided an elongated joint structure for a roofing assembly covering a roof substrate, the joint structure comprising cleat means extending longitudinally along the joint structure to define first and second transverse directions across the joint. The cleat means has cleat hook means and is rigidly anchored to the roof substrate. A first panel is provided with a first edge extending along the joint structure, a first major section extending from the first edge in the first transverse direction across the joint, and panel hook means associated with the first edge. The panel hook means is engaged with the cleat hook means to restrain the first panel from movement away from the cleat means in the first transverse direction across the joint. A second panel is provided with a cover section overlying the cleat hook means and engaged panel hook means, a second major section extending from the cover section in the second transverse direction from the joint, and an attachment section extending from the cover section in the first transverse direction. The attachment section of the second panel is rigidly attached to the first major section of the first panel. In this arrangement, the first and second panels are rigidly attached to one another and are securely anchored to the roof substrate through the cleat. In advantageous distinction to the prior art, the panels are not rigidly anchored to the roof substrate, either directly or through the cleat. A slight amount of clearance where the panel hook means engages the cleat hook means thereby permits a slight amount of transverse movement of the joined panels together across the cleat. The invention thus accommodates thermally induced strains in the roofing assembly.
In accordance with a more specific feature of the invention, a joint structure as defined above is provided wherein the attachment section of the second panel has a second edge overlying the first major section of the first panel, with those sections being soldered together. Only two layers of panel material must be heated to create conditions wherein the molten solder will be drawn inwardly between the panel sections being soldered. An additional specific feature in this respect is the provision of means for blocking the flow of liquid solder in the first transverse direction away from the second edge of the second panel in order to maintain control of the molten solder and to provide a neat finished appearance. The preferred means for blocking the flow of liquid solder away from the soldered edge is a raised rib in the first panel extending parallel to and closely spaced from the second edge of the second panel.
Further regarding soldering of the first and second panels, the panels may advantageously be composed of Terne Coated Stainless Steel, a product of Follansbee Steel Corporation, assignee of the present patent application. Terne Coated Stainless Steel bears a surface layer of solder material which melts appropriately upon heating to eliminate the necessity of externally applied solder and the labor and material costs associated therewith.
In accordance with another specific feature of the invention, in addition to the provision of solder to attach the panels and to seal the joint, pop rivets are provided to rigidly connect the major section of the first panel to the overlying attachment section of the second panel. Pop rivets will securely connect the panel sections without anchoring them to the roof substrate. As discussed above, the connected panels are anchored to the roof substrate through the cleat in a manner to permit thermally induced movement of the connected panels transversely across the joint and the substrate.
Yet another specific feature of the invention provides the cleat means in the form of an elongated sheet metal cleat extending longitudinally in the direction of the joint. This advantageously facilitates installation of the joint in a straight line without the need for precise and skillful alignment of a plurality of individual cleats spaced along the joint line.
In accordance with another principal feature of the invention, there is provided a method of constructing an elongated joint between panel components of a roofing assembly covering a roof substrate. The method comprises the steps of providing components including a first panel having panel hook means defining a longitudinal direction and first and second opposing transverse directions with respect to the joint when the first panel is in a first assembled position; a cleat adapted to be rigidly anchored to the roof substrate and having cleat hook means for engagement with the panel hook means to restrain the first panel from movement from the cleat in the first transverse direction; and a second panel having an attachment section. The first panel is placed in the first assembled position, the cleat hook means are engaged with the panel hook means, and the cleat is rigidly anchored to the roof substrate. The second panel is placed in a second assembled position overlying the cleat with the attachment section thereof overlying the first panel, and the attachment section is then rigidly attached to the first panel. This results in a joint which includes a rigid connection between the panels, a rigid anchored connection between the cleat and the roof substrate, and a secure attachment of the panels to the substrate through the cleat which is transversely shiftable across the joint and substrate in response to thermally induced stresses in the panel material.
In accordance with a specific feature of the method, the panels in the assembled positions are first releasably anchored to the roof substrate at a base anchoring point to hold the panels steady against longitudinal or transverse movement out of position. The panels are then more easily rigidly attached together in the proper alignment. The releasable anchoring step is preferred to comprise the specific steps of punching a hole into the substrate through the overlapping panel sections and inserting a releasable locator pin into the hole. A second hole may be punched to provide a supplemental releasable anchoring point, preferably at a position longitudinally spaced along the joint from the base anchoring point, for insertion of a supplemental releasable locator pin. This would restrain the panels from horizontal rotation about the locator pin in the base anchoring hole and would thereby more completely hold the panels in aligned positions. Rigid connection of the overlapped panel sections by means of pop rivets and sealing of the joint with solder would then follow with subsequent removal of the releasable locator pins and sealing of the respective locator holes with solder.
Specific features of the method pertain to the riveting step. Use of a punching tool to drive the holes in which the pop rivets are inserted provides an indentation in the sheet metal panels to effectively countersink the pop rivets and avoid a disruptive burr in the material as caused by prior art screw threading methods. Importantly, setting of the pop rivets in a countersunk manner contributes to pooling of the solder thereafter applied to seal the punctures.
The principal object of the present invention is to provide a lap joint structure for adjoining sheet metal roofing panels which can accommodate thermally induced expansion and contraction of the panels while securely anchoring the panels to the roof substrate along planned lines.
Another object of the invention is to provide a securely sealed joint structure for adjoining sheet metal roofing panels which can be efficiently and easily installed without a great deal of expertise.
A further object of the invention is to provide a method of constructing a joint between adjoining sheet metal roofing panels which is more effective and less skillfully demanding than prior methods.
Yet another object of the present invention is to provide a lap joint for a sheet metal roofing assembly and a method of constructing the joint which enables the use of the elongated adjacent panels extending in planned lines from the eave to the ridge of the roof assembly.
These and other objects of the invention will become apparent from the following description of a preferred embodiment thereof taken together with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a pictorial view of a building having a roof assembly including a joint structure in accordance with the invention;
FIG. 2 is a cross sectional view of a joint structure in accordance with the invention taken on line 2--2 of FIG. 1;
FIG. 2A is an enlarged partial view of the joint structure shown in FIG. 2;
FIG. 3 is a partial top plan view, partially cut away, of the joint structure shown in FIG. 2;
FIGS. 4A-4F are cross sectional views showing a sequence of steps taken in the method of constructing a joint structure in accordance with the invention;
FIG. 5 is a partial cross sectional view of a sheet metal panel in accordance with the invention;
FIG. 6 is a cross sectional view of a prior art joint structure;
FIG. 7 is a cross sectional view of another prior art joint structure; and,
FIG. 8 is a cross sectional view of an alternate embodiment of a joint structure in accordance with the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings wherein the showings are for the purpose of illustrating a preferred embodiment of the invention and not for the purpose of limiting the invention, in FIGS. 1 and 2 there is shown a roof assembly R covering a wooden roof substrate S and including a joint structure J in accordance with the invention. The roof assembly R comprises adjacent elongated panels P extending from the eave 12 to the ridge 14, with an adjacent pair of panels, such as panels 16 and 18 shown in FIG. 2, being joined by the joint structure J. The joint structure J is likewise elongated to extend longitudinally between the joined panels 16 and 18 and to define transverse right and left hand directions r and 1 thereacross. More specifically, the joint structure J comprises a right hand or first panel 16, a left hand or second panel 18, and a cleat 20.
The first panel 16 includes a major portion 22 and a hook or hem section 24. The hem section 24 includes a first free edge 26 and is folded back over the major portion 22 to define a folded terminal edge 28 and an open hem pocket 30. A first attachment section 32 of the major portion 22 is defined adjacent the open hem pocket 30.
The cleat 20 is preferred to comprise an elongated component extending longitudinally in the direction of the joint structure J and is formed into substantially parallel sections including a base section 34, an intermediate section 36, and a hook section 38 arranged with respect to the intermediate section 36 to define an open cleat pocket 40. A cleat space 41 is defined between the free edge 42 of the hook section 38 and the base section 34 as shown in FIG. 2. The cleat 20 takes an assembled position with the hook section 38 received within the open hem pocket 30 of the first panel 16, and with the hem section 24 of the first panel 16 likewise received within the open cleat pocket 40 as shown in FIG. 2. The first panel 16 is thereby restrained from movement away from the cleat 20 in the right hand direction r. Slight clearance spaces 43 and 44 are preferably provided between the innermost ends of the open pockets 30 and 40 and the free edges 42 and 26 of the sections 38 and 24 respectively received therein. The base section 34 of the cleat 20 is rigidly anchored to the substrate S by means of nails 46.
The second panel 18 comprises a second attachment section 48 overlying the first attachment section 32 of the first panel 16 and including a second free edge 50; a second major portion 52 generally co-planer with the second attachment section 48 and extending from the joint structure S in the left hand direction 1 atop the roof substrate S; and a cover section 54 extending between the second attachment section 48 and the second major portion 52 out of the plane of those components to overlie the cleat 20 and the hem section 24 of the first panel 16. Angularly disposed transition portions 55 and 57 of the cover section 54 provide strength. A rigid attachment between the second attachment section 48 of the second panel 18 and the first attachment section 32 of the first panel 16 is made by means of pop rivets 56 and solder 58.
It is to be understood that the elongated panels P typically have a left hand sided formed as the left hand side of the first panel 16 shown in FIGS. 2 and 3, and an opposite right hand side formed as the right hand side of the second panel 18 as shown in order to provide successive joint structures J between successive adjacent panels P. Furthermore, one longitudinal end of a panel P may have a narrower width than the other end to fit into a curved roof structure.
The joint structure J as thusfar defined securely anchors the roof assembly R to the substrate S yet fully accommodates thermally induced strains in any direction across the roof assembly R. This feature of the invention is provided by the novel arrangement wherein the two joined panels 16 and 18 are rigidly connected only to one another and not to the cleat 20 or the underlying substrate S. In contrast to the prior art lap joint structure known as a flat lock joint with cleats as shown in FIG. 6 to have a rigid soldered connection between the joined panels and the cleats, the joint structure J in accordance with the present invention, enables the joined panels 16 and 18 to shift together in the right and left hand directions r and l as permitted by the clearance spaces 43 and 44 and the cleat space 41. Movement in the longitudinal direction of the joint structure S is also permitted as needed by the arrangement where the hem pocket 30 and the cleat pocket 40 are open with respect to the sections 38 and 24 respectively received therein. The same structural advantages of the present invention are obtained over the prior art lap joint structure shown in FIG. 7 which also has a rigid connection between the joined panels and the underlying substrate.
A method of constructing the joint structure J is also provided in accordance with the present invention. The cleat 20 is placed in the assembled position described above with the hook section 38 received within the hem pocket 30 of the first panel 16, and the base section 34 of the cleat 20 is then rigidly anchored to the substrate S by means of nails 46 or other suitable rigid fasteners such as screws or the like. Use of an elongated cleat 20, preferably co-extensive with the elongated joint structure J, as opposed to a row of spaced cleats as indicated in FIG. 6 greatly simplifies this initial step in the construction process. The second panel 18 is then placed in position with the second attachment section 48 overlapping the first attachment section 32 of the first panel 16 as shown in FIG. 2 such that the cover section 54 overlies the cleat 20 and the engaged hem section 24. A rigid connection between the panels 16 and 18 is then made in accordance with the sequence of steps illustrated in FIGS. 4A through 4F.
In FIGS. 4A and 4B a punching tool 60 is shown to drive a hole 62 into the substrate S through the first and second attachment sections 32 and 48 of the first and second panels 16 and 18 with the effect of producing a slight depression 64 in those sections of the panels about the hole 62. In FIGS. 4C and 4D a locator pin 66 is shown to be loosely inserted into the hole 62 as a temporary anchor for the panels 16 and 18 in order to hold them in their assembled positions before a permanent rigid connection is made therebetween. One or more of these anchoring arrangements may be made as required since a single temporary anchor will restrain the panels 16 and 18 from lateral movements across the joint structure J, but a second anchor spaced longitudinally from the first may be required to restrain the panels from rotation about the first anchor. Placement of a releasable anchor at each opposite end of the elongated joint structure J, when the panels are placed in proper alignment, would thus be an efficient means of holding the panels in line. With the panels 16 and 18 thus releasably held in line, a plurality of pop rivets 56 are installed in a generally staggered array along the longitudinal extent of the overlapping attachment sections 32 and 48 as shown in FIGS. 2 and 3.
An important feature of the invention arises in the use of pop rivets as illustrated in FIGS. 4E and 4F wherein it is shown that the depression 64 caused by use of the driving tool 60 enables the heads 68 of the pop rivets 56 to rest in a somewhat countersunk position with respect to the overlapping panel sections 32 and 48. In the case of a wooden substrate S as shown in FIGS. 4F and 2A, or another substrate which would similarly yield under the impact force of the driving tool 60, the depression 64 would further provide clearance between the substrate and the panel sections for expansion of the rivet shaft into the position wherein it holds the two Joined panel sections together. These particular steps of the present method provide a distinct advantage over prior art methods using sheet metal screws which tend to raise a burr beneath the overlapping panel sections to disrupt the level contour of the completed roof assembly, and which do not countersink the screw heads to provide a relatively smooth surface.
Following installation of the pop rivets as described above, the overlapping panel sections 32 and 48 are sealed together with solder. The present invention also provides several advantages over the prior art in the soldering step. In distinction to the prior art configuration shown in FIG. 6 wherein six overlapping layers of sheet metal material must be thoroughly heated by a soldering iron in order to create conditions required for a thorough application of molten solder, only the two overlapping attachment sections 32 and 48 of the first and second panels 16 and 18 need to be heated in accordance with the present invention. This not only reduces the operator skill, time, and consequent cost of the soldering operation, but also greatly reduces the risk that an incomplete seal will be made. As shown in FIG. 2A, a spot of solder may be provided atop each rivet head 68 in order to provide a thoroughly complete seal as well as a smooth finished appearance.
Another beneficial feature of the invention is the provision of means for containing the molten solder at a region closely adjacent the second free edge 50 of the second panel 18 where it overlaps the first panel 16. This means is preferred to take the form of a raised rib 70 extending along the major portion 22 of the first panel 16 parallel to and closely spaced from the second free edge 50 as shown in FIGS. 2 and 3. The raised rib 70 acts as a dam for containment of molten solder which might otherwise flow outwardly from the second free edge 50 onto the major portion 22 of the first panel 16.
An additional feature of the invention regarding soldering is the use of Terne Coated Stainless Steel, a product of Follansbee Steel Corp. Terne Coated Stainless Steel is pretinned to bear a surface coating of solder material 72 as shown in FIG. 5. Use of Terne Coated Stainless Steel insures complete application of molten solder between the overlapping panel sections as shown in FIG. 3. In accordance with the present invention, the sheet metal panels may bear a partial surface coating of solder material 74 or a complete surface coating of solder material 72 as shown in FIG. 5.
The invention has been described with reference to the preferred embodiment. It will be appreciated that modifications or alterations which would not deviate from the present invention will occur to others upon their reading and understanding of this specification. For example, in FIG. 8 there is shown an alternate joint structure J including an alternate cleat 80 and an alternate first panel 90. The alternate cleat 80 comprises a base section 82 and a hook section 84 folded back over the base section 82 in the left hand direction l as shown. The alternate first panel 90 includes a major portion 92 with an attachment section 94 and a raised rib 96; an intermediate section 98 spaced above the plane of the attachment section 94 and extending tberefrom in the left hand direction l, and a hem section 100 folded back beneath the intermediate section 98 to define a hem pocket open to the right hand direction r as shown. This arrangement enables placement and anchoring of the alternate cleat 80 to the substrate S before placement of the alternate first panel 90 in its assembled position with respect to the cleat 80, whereby all of the cleats may first be installed along established lines to thereafter avoid precise attention to alignment upon installation of each of the panels to be engaged therewith. Also, an alternate second panel 102 is shown in FIG. 8 to have a cover section 104 and a generally distinct major portion 106 which is permitted to descend to the level of the substrate S from the cover section 104 without a sharp transition section on that side. In this respect, both transition sections 55 and 57 of the cover section 54 described above could be omitted but are employed in the preferred embodiment to impart strength to the cover section and to insure overlapping contact of the adjacent attachment section over the first panel. It is intended that all such modifications and alternate arrangements be included insofar as they come within the scope of the dependent claims or the equivalence thereof.
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A lap joint structure for adjoining panels of a sheet metal roofing assembly permits shifting of the joint panels longitudinally and transversely with respect to the joint as caused by thermally induced expansion and contraction, as well as providing a securely anchored connection of the panels to the roof substrate. Two adjacent panels are rigidly connected to one another, an underlying cleat is rigidly connected to the roof substrate, and the two joined panels are securely connected to the cleat with clearance allowed for thermally induced movements of the panels across the substrate.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention pertains to the art of refrigerators and, more particularly, to an icemaker system for in a refrigerator.
[0003] 2. Discussion of the Prior Art
[0004] Whether it be to ensure an adequate amount of ice for a party or keep up with daily demand, there is always a need to decrease ice production time. In the art of refrigerated appliances, it is known to employ fans or other similar devices to decrease an amount of time required to produce ice. Typically, the fan is oriented to direct air from an evaporator portion of the refrigerator across an ice mold. The flow of air disturbs a thermal barrier that is present at the ice mold increasing temperature transfer rates and, as a consequence, decreasing ice production time.
[0005] While the above arrangements utilize fans to blow evaporator air across the ice mold, other arrangements directly expose the ice mold to the evaporator. The evaporator is part of a primary refrigeration system that is employed to maintain temperatures in a fresh food and freezer compartment of the refrigerator. While effective, the above described systems typically rely on a cooling demand signal. That is, regardless of the need for ice, the above described systems only function when either the fresh food or freezer compartments require cooling which necessitates the activation of the refrigeration system. Correspondingly, even during periods when no ice production is required, the above described systems function upon activation of the refrigeration system.
[0006] Regardless of the teachings in the prior art, there still exists a need for a system to reduce ice production time in a refrigerator. More specifically, there exists a need for a system that can, upon demand, decrease ice production time regardless of a need for cooling in the refrigerator.
SUMMARY OF THE INVENTION
[0007] The present invention is directed to a refrigerator including a fresh food compartment, a freezer compartment, a refrigeration system and an icemaker. In accordance with the invention, the refrigeration system includes a plurality of refrigeration components which operate synergistically to establish and maintain desired temperatures in the refrigerator. The refrigeration components include at least a preferably variable speed compressor, a condenser and a condenser fan. In addition, the refrigeration system includes a refrigeration loop that carries a flow of refrigerant to the plurality of refrigeration components. The refrigerator also includes various sensors that monitor temperature conditions within the fresh food and freezer compartments, as well as a level of ice in, for example, an ice storage bin portion the icemaker.
[0008] In further accordance with the invention, a portion of the refrigeration loop passes through the icemaker. More specifically, the refrigeration loop includes an ice maker section that passes through an ice mold portion of the icemaker. In this manner, the flow of refrigerant passing through the refrigeration loop supplies additional cooling to speed the production of ice. In still further accordance with the invention, the refrigeration loop includes a diverter valve and an icemaker bypass. The diverter valve is selectively closed to divert the flow of refrigerant away from the icemaker section and into the icemaker bypass during periods of low or no ice demand.
[0009] In accordance with the most preferred form of the invention, the refrigerator includes a controller that is operatively coupled to each of the refrigeration system and the icemaker. The controller, upon sensing a need for an ice production cycle, activates the refrigeration system regardless of a need for cooling in the fresh food and/or freezer compartments.
[0010] Additional objects, features and advantages of the present invention will become more readily apparent from the following detailed description of a preferred embodiment when taken in conjunction with the drawings wherein like reference numerals refer to corresponding parts in the several views.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a partial perspective view of a bottom-mount refrigerator incorporating an icemaker system constructed in accordance with the present invention; and
[0012] FIG. 2 is a schematic representation of the icemaker coupled to a refrigeration system of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0013] With initial reference to FIGS. 1 and 2 , a refrigerator constructed in accordance with the present invention is generally indicated at 2 . As shown, refrigerator 2 includes a cabinet shell 6 provided with an upper fresh food compartment door 10 which is adapted to close off an upper fresh food compartment 12 . As known in the art, fresh food door 10 is adapted to pivot about a vertical axis defined by upper and lower hinges (not shown). Within cabinet shell 6 is also defined a freezer compartment, generally indicated at 15 , which is defined by a liner 18 . Although not shown, freezer compartment 15 is adapted to be closed off by means of a door. With this general construction, refrigerator 2 defines a bottom mount style unit. As known in the art, the door associated with freezer compartment 15 can either be mounted for a pivotable movement about a vertical axis similar to fresh food door 10 , or mounted upon slide assemblies which permit linear shifting of the freezer door relative to cabinet shell 6 .
[0014] Mounted within freezer compartment 15 is a drawer that preferably takes the form of a basket 40 . As shown, basket 40 generally has a meshed wire construction. However, as will become fully evident upon reading the remainder of this description, the drawer can take various forms in accordance with the overall invention. At this point, it is simply important to note that basket 40 can be selectively shifted into and out of freezer compartment 15 . Although not depicted in this figure, there may be one or more additional baskets within freezer compartment 15 that provide additional storage for food items.
[0015] Also shown mounted in freezer compartment 15 is an icemaker 50 . Ice maker 50 is fixed against liner 18 at brackets 53 and 54 and includes an ice mold 55 and a bail arm 56 . In the embodiment shown, an ice storage bin 58 is positioned below icemaker 50 so as to receive and retain a quantity of ice produced by icemaker 50 for use by a consumer(s). In a manner widely known in the art, bail arm 56 is adapted to be raised and lowered based on a level of ice present in ice storage bin 58 . Actually, bail arm 56 acts as a sensor that determines when the quantity of ice in ice storage bin 58 falls below a predetermined level in order to signal the need for a new ice production cycle. At this point it should be understood that, while shown mounted in freezer compartment 15 , icemaker 50 could also be located in fresh food compartment 12 in a specialty or icemaker compartment shown schematically at 70 in FIG. 2 .
[0016] Refrigerator 2 includes a control system 80 that selectively activates a refrigeration system 90 to establish and maintain a selected temperature in fresh food compartment 12 and freezer compartment 15 . Towards that end, if a demand for cooling is sensed, such as by a fresh food compartment sensor 93 located in fresh food compartment 12 and/or a freezer compartment sensor 94 located in freezer compartment 15 , refrigeration system 80 is activated to ensure that refrigerator 2 is maintained at the selected temperature(s). In order to satisfy the demand for cooling, refrigeration system 90 includes a plurality of refrigeration components. In accordance with the invention as represented best in FIG. 2 , the refrigeration components include a compressor 100 , a condenser 104 and a condenser fan 106 which are preferably arranged in a mechanical zone 110 of refrigerator 2 . In addition, arranged at or near freezer compartment 15 is an evaporator 116 having an associated evaporator fan 118 . The refrigeration components and, more specifically, the compressor 100 , condenser 104 and evaporator 116 are interconnected by a refrigeration loop 130 which carries a flow of refrigerant. In order to optimize the cooling capabilities of refrigeration system 90 , an expansion valve 141 is arranged in refrigeration loop 130 between evaporator 116 and condenser 104 .
[0017] In a manner known in the art, compressor 100 establishes or creates a flow of compressed refrigerant which is guided towards evaporator 116 . Evaporator fan 118 establishes an airflow across evaporator 116 which is cooled by the compressed refrigerant. The cooled airflow passes into freezer compartment 15 to establish and maintain the selected temperature therein. After passing through evaporator 116 , the now warm flow of refrigerant passes into condenser 104 . Condenser fan 106 creates an airflow across condenser 104 to dissipate heat carried by the flow of refrigerant. At this point, the refrigerant re-enters compressor 100 to start the cycle anew.
[0018] In accordance with the invention, refrigeration loop 130 includes an icemaker section 161 that passes through icemaker 50 . Preferably, icemaker section 161 extends directly adjacent to or is integrally formed into ice mold 55 . In any case, icemaker section 161 guides compressed or cold refrigerant about ice mold 55 in order to speed the formation of ice crystals in icemaker 50 . In further accordance with the invention, refrigeration loop 130 includes an icemaker bypass section 170 that selectively isolates icemaker section 161 from refrigeration loop 130 . More specifically, a valve 174 , operatively connected to control system 80 , is positioned downstream of icemaker bypass portion 170 in icemaker section 161 . Valve 174 is shiftable between an open position allowing refrigerant to pass into icemaker section 161 and through ice mold 55 and a closed position causing all of the flow of refrigerant to pass through icemaker bypass section 170 . With this arrangement, refrigerant passes through icemaker section 161 only during an ice production cycle and control system 80 can optimize the flow of refrigerant in refrigeration system 90 . In order further optimize or provide additional efficiency gains in refrigeration system 90 , a second expansion valve 176 is preferably arranged between icemaker section 161 and evaporator 116 .
[0019] In accordance with the most preferred form of the present invention, when the quantity of ice falls below a predetermined level in ice storage bin 58 , control system 80 initiates an ice production cycle which, regardless of a need for cooling in fresh food compartment 12 or freezer compartment 15 , activates refrigeration system 90 . Once activated, valve 174 opens, thereby allowing the flow of refrigerant to pass into icemaker section 161 and circulate about ice mold 55 to provide additional cooling to facilitate the production of ice crystals. This additional cooling is particularly necessary if icemaker 50 is located within fresh food compartment 12 . Further enhancement in ice production is achieved by the inclusion of a fan 183 used to direct a cooling airflow onto ice mold 55 .
[0020] In accordance with one aspect of the invention, compressor 100 is constituted by a variable speed compressor. By incorporating a variable speed compressor into refrigeration system 90 , the flow of refrigerant through refrigeration loop 130 can be optimized. More specifically, during periods of no ice production or no need for an ice production cycle, compressor 100 can operate at a low speed. Likewise, during periods when only cooling is needed in fresh food compartment 12 or freezer compartment 15 , variable speed compressor 100 can be operated at a low speed. However, in the event that fresh food compartment 12 and/or freezer compartment 15 require cooling and an ice production cycle is needed, variable speed compressor 100 can be operated at a full speed to ensure the optimal flow of refrigerant through refrigeration loop 130 .
[0021] In accordance with another aspect of the present invention, control system 80 can selectively activate a harvest heater 190 in order to slow the formation of ice crystals in ice mold 55 . That is, a consumer can select a clear ice mode for icemaker 50 through user controls 200 which preferably constitute a combination input panel/display unit located within cabinet 6 or on fresh food compartment door 10 . The clear ice mode actually slows the production of ice, thereby allowing air trapped in the ice mold to escape forming substantially, perfectly clear ice cubes.
[0022] Based on the above, it should be understood that the icemaker system of the present invention provides an efficient mechanism for reducing ice production time in a refrigerator. More specifically, the present invention, in addition to speeding ice production time in an icemaker provided in a freezer compartment of the refrigerator, will foster faster ice production in an icemaker compartment located in a fresh food compartment of the refrigerator. That is, by directing refrigerant directly through the ice mold, the icemaker will rapidly form ice crystals despite the lower temperatures in the fresh food compartment. Therefore, while shown in connection with a bottom mount refrigerator, the icemaker system of the present invention could also be employed in top mount, side-by-side, French door or the like models.
[0023] Although described with reference to a preferred embodiment of the invention, it should be readily understood that various changes and/or modifications can be made to the invention without departing from the spirit thereof. For instance, although the rapid ice mode is preferably, automatically established based on the position of bail arm 56 , a user could also establish the rapid ice mode through user control 200 . This feature could be extremely beneficial in connection with a party or other gathering when the user knows that an abundance of ice will be needed in a relatively short period of time. In general, the invention is only intended to be limited by the scope of the following claims.
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An icemaker system provided in a refrigerator is designed to reduce an amount of time required to produce ice. The refrigerator includes a refrigeration system including a number of refrigeration components and a refrigeration loop. The refrigeration loop includes an icemaker section that carries a flow of refrigerant to an ice mold portion of the icemaker system and a bypass section that isolates the icemaker system from the flow of refrigerant. A control system automatically activates the icemaker system regardless of a need for cooling. That is, upon sensing a demand for ice, the control system opens a valve to cause refrigerant to flow through the icemaker section and activates the refrigeration components to speed ice production whether or not additional cooling is required in fresh food and/or freezer compartments.
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BACKGROUND OF THE INVENTION
This invention concerns compositions which can be described as melt processable pseudointerpenetrating networks of silicones in thermoplastic matrices. This invention also relates to methods for the formation of these compositions.
Previous investigations have demonstrated that silicones may be incorporated into thermoplastic resins at low levels in order to enhance wear friction and release properties. These silicones, however, are low molecular weight resins which are readily extractable from the matrix resins. Incorporation of silicone at levels above 2% and in some cases even between about 0.1% and 2% can cause catastrophic reductions in mechanical properties and melt rheology. The present invention reveals that judiciously selected silicone systems which are vulcanized within a thermoplastic matrix to form pseudointerpenetrating polymer networks will not adversely affect polymer properties.
SUMMARY OF THE INVENTION
There have now been discovered new compositions comprising a silicone component vulcanized within a polymeric thermoplastic matrix to form a pseudointerpenetrating polymer.
This invention is also directed to methods of producing pseudointerpenetrating silicone polymers by curing or vulcanizing a silicone within a polymeric thermoplastic matrix at elevated temperatures.
Advantageous characteristics of the compositions of this invention are surface and dielectric properties which approach those of silicones and mechanical properties which approach those of the thermoplastic matrices.
DETAILED DESCRIPTION OF THE INVENTION
The compositions of this invention are formed by the catalyzed curing or vulcanization of a silicone in a compatible polymeric thermoplastic matrix at elevated temperature. A silicone is any of a large group of siloxane polymers based on a structure comprising alternate silicone and oxygen atoms with various organic radicals attached to the silicon.
The amount of silicone in the resultant compositions of the present invention can range from between about 1 weight percent and about 40 weight percent.
Vulcanization (curing) can be defined as any treatment that decreases the flow of an elastomer, increases its tensile strength and modulus, but preserves its extensibility. These changes are generally brought about by the cross-linking reactions between polymer molecules, but for purposes of this invention vulcanization is used in a broader sense to include chain extension as well as cross-linking reactions.
The polymeric thermoplastic matrices of this invention are conventional thermoplastic resins including, but not limited to polyamides, thermoplastic polyurethanes, bisphenol A polycarbonates, styrenics, polyacetals, etc.
In a particular embodiment of this invention a two part vulcanizing silicone which, depending on molecular structure will undergo predominantly chain extending or cross-linking reactions, is vulcanized in a suitable thermoplastic matrix. One polymeric silicone component of the two part silicone contains silicone hydride (Si--H) groups. The other polymeric component contains unsaturated groups, preferably vinyl. Non-limiting examples of other unsaturated groups that can be employed include allyl--CH 2 CH═CH 2 and hexenyl--(CH 2 ) 4 CH═CH 2 . Alternatively, both the hydride and unsaturated group can be part of one polymeric silicone. In the presence of a catalyst, generally a platinum complex, silicon hydride adds to the unsaturated group, e.g., a vinyl group, to create an ethylene linkage as follows: ##STR1## The principles of this chemistry are well-known to those skilled in the art.
Vinyl containing polymers that can be employed in the present invention have viscosity ranges of between about 500 and about 100,000 ctsk, with polymers having viscosities of between about 1000 and about 65,000 ctsk preferred. Hydride containing polymers that can be utilized in the present invention have viscosities of between about 35 and about 10,000 ctsk, with a preferred viscosity range of between about 500 ctsk and about 1,000 ctsk. Molecular weights are correlated to viscosity. Thus a vinyl terminated polymer having a viscosity of 1,000 ctsk has a molecular weight of 28,000.
In a preferred embodiment of this invention pellets are formed of the compositions of this invention. These pellets can be readily utilized for injection molding or extrusion. The pellets may either contain silicones which have been vulcanized or contain all the materials necessary to form the vulcanizate during injection molding or extrusion.
The silicones of this invention will generally undergo one of two types of mechanisms, namely, chain-extension or cross-linking. The silicones which during vulcanization undergo primarily chain-extension yield thermoplastic components (plastics capable of being repeatedly softened by increases in temperature and hardended by decreases in temperature). Silicones which undergo primarily cross-linking during vulcanization yield compositions that have thermosetting properties (resins which cure by chemical reaction when heated and, when cured, cannot be resoftened by heating).
In the case of the predominantly chain-extended or thermoplastic compositions of this invention, a thermoplastic resin is combined with silicone components including a hydride-containing silicone and a vinyl silicone. The vinyl silicone generally contains from about two to about four vinyl groups, preferably with two such groups in terminal positions. The hydride-containing silicone contains 1 to 2 times the equivalent of the vinyl functionality. The two silicones are mixed in a ratio so that the hydride groups to vinyl groups is between about 1.2:1 and about 6:1.
Theoretically only a 1:1 ratio is necessary, but it has been found that a higher ratio as indicated above is required. The silicone hydride polymers are not as stable as the silicone vinyl polymers. In the presence of amines or hydroxyls, the silicone hydrides can react and liberate hydrogen thus yielding SiN.tbd. or Si--OR. Thus the simplest practical solution to this problem is to maintain hydride levels higher than stoichiometric requirements.
The typical remaining substituents on the silicones are methyl groups. However, in order to insure compatability with the thermoplastic matrix resin other groups such as phenyl, longer chain alkyl or cyanopropyl groups may replace some of the methyl groups.
A platinum complex preferably derived from chloroplatinic acid and a vinyl siloxane is added to the mixture just prior to meltmixing so that the amount of platinum is equal to 1-15 ppm. The vinyl siloxane forms an active complex with the platinum which is soluble in the silicones to be cross-linked. The mixture is meltmixed by a process such as extrusion and is then pelletized.
A predominantly cross-linked structure in which the resulting composition has thermosetting properties is achieved by extruding the vinyl and hydride containing silicones separately into two portions of the base polymer. The vinyl-containing silicone contains from about two to about thirty vinyl groups and the hydride-containing silicone contains from two to ten times the equivalent of the vinyl functionality. In this case the hydride functional silicone is the cross-linker since it contains a relatively higher number of sites per chain for cross-linking. The relationship of these two materials can, however, be reversed. The ultimate ratio of the silicones is adjusted in either case so that the ratio of the hydride groups to the vinyl groups in the composition is between about 1.2:1 and about 6:1.
Once the separate extrusions are prepared, a physical blend of the pellets is made. A platinum complex is then tumbled into the mixture. When the pellets are melted together the silicones react. Most of the thermosetting reaction takes place during injection molding or extrusion of the mixture and may be completed during a post-cure. A number of permutations of the above are evident to those skilled in the art. One component pellet could contain for example predominantly vinyl silicone with some of the hydride silicone. In some instances the two polymers do not have to be isolated prior to melt mixing. In fact, vinyl groups and hydride groups can be on the same chain. Having the materials on separate pellets reduces (or eliminates) surface cure of the pellets. Another solution to this problem would be to use a fugitive inhibitor of the platinum catalyst.
The invention is further described by reference to the following specific, non-limiting examples.
EXAMPLE 1
A homogeneous physical blend of the following materials was prepared:
______________________________________nylon 6/6, Monsanto molding grade pellets 9000 gpolydimethylsiloxane, vinyldimethylsiloxy 400 gterminated, 10,000 ctsk.polydimethylsiloxane, hydrodimethylsiloxy 600 gterminated, average of 1 hydromethylsiloxygroup per chain, 10,000 centistokes (ctsk)______________________________________
Within one hour of extrusion, 1 g of a platinum complex in methylvinylcyclosiloxane containing 3.5% Pt was added to the mixture. The platinum complex utilized throughout the examples were the methylvinyl cyclic siloxane analogs of the Karstedt U.S. Pat. Nos. 3,715,334 and 3,775,452. The mixture was extruded at 340°-355° C. and chopped into pellet form. The pelletized composition was molded into standard ASTM specimens. The ASTM testing protocol was used for flexural strength, tensile strength and water absorption. Properties of the resultant composition are tabulated in the Table hereinbelow.
EXAMPLE 2
Utilizing the same silicones as described in Example 1 a moldable thermoplastic urethane/silicone composition was prepared.
______________________________________polyester urethane, Mobay Texin 55D 9250 gpolydimethylsiloxane, vinyl terminated 300 gpolydimethylsiloxane, hydride containing 450 gfumed silica, Cabot MS-7 5 gplatinum complex (added after extrusion) 1 g______________________________________
Fumed silica served both as a reinforcing agent and a process aid. In this example, feed problems were observed and the fumed silica absorbed the silicone making it easier to process. The properties of specimens prepared from the above described pelletized extruded material are tabulated in the Table hereinbelow.
EXAMPLE 3
The following composition was extruded and molded:
______________________________________polyester urethane Mobay Texin 480A 9000 gpolydimethylsiloxane-3% diphenylsiloxane 400 gcopolymer, vinyldimethylsiloxy terminatedpolydimethylsiloxane, hydride containing 600 gplatinum complex (added after extrusion) 1 g______________________________________
Properties of the composition formed according to Example 3 are given in the Table hereinbelow.
EXAMPLE 4
The following composition was extruded and molded:
______________________________________bisphenol A polycarbonate, Mobay M-50 9500 gpolydimethylsiloxane-10% phenylmethylsiloxane copolymer, vinyldimethylsiloxy 200 gterminatedpolydimethylsiloxane, hydride containing 300 gplatinum complex (added after extrusion) 1 g______________________________________
Properties of the composition formed according to Example 4 are given in the Table hereinbelow.
EXAMPLE 5
The following mixtures were extruded then pelletized:
______________________________________Part Apolyester urethane, Mobay Texin 480A 9000 gpolydimethylsiloxane-15% methylhydrosiloxane 500 gcopolymer, trimethylsiloxy terminated10,000 ctskpolydimethylsiloxane, vinyldimethylsiloxy 500 gterminated 65,000 ctskamorphous silica, Minusil 50 gPart Bpolyester urethane, Mobay Texin 480A 8800 gpolydimethylsiloxane, vinyl terminated 1200 g65,000 ctskamorphous silica 25 g______________________________________
Part A and Part B were extruded separately. A 1:1 (weight ratio) physical blend of two different extrusions was made. 2.5 g of platinum complex and 5 g of 3-methylbutynol, a fugitive inhibitor of hydrosilylation (hydrosilylation is the process of adding Si-H across a double bond) were tumbled into the mixture and prior to hermetically sealing it in a can.
The mixture was molded under normal conditions and post-cured an additional 1 hour at 80° C.
The present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof and, accordingly, reference should be made to the appended claims, rather than to the foregoing specification, as indicating the scope of the invention.
TABLE__________________________________________________________________________ ExamplesProperties 1 2 3 4 5__________________________________________________________________________Thermoplastic base Nylon 6/6 Urethane 55D Urethane 80A Polycarbonate Urethane 80APredominant Melt Thermoplastic Thermoplastic Thermoplastic Thermoplastic ThermosetCharacteristics% Silicone 10 7.5 10 10 11Flexural Strength, 15,900 730 11,000psiFlexural modulus, 390,000 -- 325,000psiIzod impact strength,ft-lb/innotched 0.8 >40 >40unnotched 21.3 >40 16Water absorption % 1.2 .03 .04 .15 .04(24 hours)Tear Strength ("C"), 750 450 500pliTensile Strength, 9,600 6200 6.000psi__________________________________________________________________________
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A melt processable pseudointerpenetrating network of silicones in thermoplastic matrices and a method of producing same is provided by vulcanizing the silicones within the matrices. In a preferred embodiment a two part silicone comprising silicon hydride groups and silicon vinyl-containing groups are reacted in the presence of a platinum complex. Depending on certain parameters chain-extended (thermoplastic) or cross-linked (thermosetting) compositions are produced.
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RELATED APPLICATION DATA
[0001] This application claims priority from U.S. provisional application Serial No. 60/440,469 filed Jan. 15, 2003.
FIELD OF INVENTION
[0002] The present invention relates to power semiconductor devices and more particularly to power diodes with extremely high ruggedness.
BACKGROUND OF THE INVENTION
[0003] Diodes are semiconductor devices made of two oppositely doped semiconductor layers which are characterized by the ability to block high voltage in the reverse direction with very low leakage current and carry high current in the forward direction with low forward voltage drop. They are therefore unidirectional switches which allow signal and power to pass in one direction but not the other. They are widely used in power electronic circuits to provide the functions for freewheeling, rectification, and snubbing in converters, inverters, motor controls, switch mode power suppliers, power factor correction, inductive heating, welding, uninterruptible power supplies and many other power conversion applications.
[0004] These power diodes, including one subgroup referred to as FREDs (Fast Recovery Epitaxial Diodes) and another subgroup using bulk semiconductor material, usually consist of an active area and a peripheral edge region. The active area in the center of the semiconductor device carries high current in the forward conduction and blocks high voltage in the reverse direction with low leakage. The peripheral edge region must also block the same high reverse voltage with equally low reverse leakage current through the use of guard-rings, bevels, grooves and other surface field spreading structures to support the high voltage in reverse blocking. For purposes of illustration, the drawings and ensuing discussions focus primarily on the FREDs. However, the inventive principles apply equally to all types of diodes as well as devices possessing diode-like structures as part of the device construction.
[0005] In modern power conversion applications, these diodes are used in conjunction with other high current, high voltage semiconductor devices such as high frequency Insulated Gate Bipolar Transistors (IGBTs) and power MOSFETs. In such high frequency and high power applications, particularly in power electronic circuits with inductive loads, the power diodes are required not only to have high breakdown voltage and high current capability but also to have high ruggedness.
[0006] [0006]FIG. 9 shows a common boost circuit where a fast recovery diode can be used. The lower input voltage V1 is converted to a higher output voltage V2 to drive a load. V1 is represented here as a DC voltage. In extended applications, it can be a rectified voltage off the AC line. As shown, the circuit uses a single power switch Q and a single diode D. L and C are an inductor and a capacitor. When the power switch is conducting, it stores energy in the inductor. When it is turned off, the stored energy is diverted into charging the capacitor C. The value of V2 is dependent on the switching frequency, the duty ratio and the resistance and capacitance in the circuit. The maximum voltage applied across the diode D is about the difference between the output voltage V2 (neglecting diode forward voltage drop) and voltage drop across the power switch. When the diode is not rugged, this voltage is kept below 60-70% of the diode rated voltage so that noise and spikes inherent in the environment will not accidentally spike above the diode avalanche voltage, causing it to fail. This imposes an undesirable guard-band condition. If rugged diodes are available, one can either raise the output operating voltage or use a diode with a lower blocking voltage in the same circuit. In the latter case, a lower voltage will have associated with it a lower forward voltage drop, therefore, lower conduction loss, and furthermore a lower recovery loss. The circuit layout will generally not change when a rugged diode is used. The main difference is in improved circuit reliability and efficiency.
[0007] The above-mentioned ruggedness is usually measured by its Unclamped Inductive Switching (UIS) capability, i.e. the ability of the device to go into avalanche and dissipate all the energy stored in the inductive load without suffering any damage. For conventional diodes (including FREDs) which are most popular and available in the present market, it is easy to get high voltage and high current ratings, e.g. 1200V/200 A, but it has not heretofore been possible to get high UIS capability. The highest UIS capability rating we can find so far in the market is 20 mJ at 1 A for Stealth Diodes (Trade Mark of Fairchild Semiconductors) rated at forward currents of 8 A and 15 A with 600V reverse blocking voltage and 30 A with 1200V reverse blocking voltage. (See referenced Product Data Sheets for these devices from Fairchild Semiconductors). Such low UIS energy capability is hardly adequate to prevent the diodes from being damaged in the presence of voltage spikes, let alone to protect other devices in such circuits. Therefore, to have high UIS capability for diode products is an important objective.
[0008] The ensuing discussions and illustrations are given for a P+N diode structure. It is obvious that the specific ideas of the invention apply equally well to an N+P diode if the polarities of the appropriate dopants are reversed.
[0009] Conventional diodes are made by introducing typically a P-type dopant such as boron, gallium, or aluminum into an N-type semiconductor substrate and diffuse it to an appropriate depth to create a PN junction. This P-dopant forms the central active area of the device for forward conduction. The substrate doping level and thickness of the N-type region are adjusted so as to obtain the desired blocking voltage and the desired forward voltage since the product of forward current and forward voltage measures power loss by the diode as it controls electric power. At the periphery, different voltage spreading and electric field reduction techniques are commonly used to withstand the reverse blocking voltage. The P-type doping level and junction depth are varied dependent upon the desired blocking voltage and the voltage blocking scheme used. In general, sufficient P dopant is introduced so that, up to the avalanche voltage, there remains substantial P-dopant to prevent “reach-through” conduction to the electrode connected to the P region. Design of the P-dopant profile can be made by considering charge balance on the P side and the N side of a PN junction under the designed reverse voltage. For example, it is generally sufficient to block 1200V with a P-diffusion of about 5 to 8 μms (microns) employing multiple plane guard-rings and field plates at the device periphery with a surface doping concentration anywhere from 1.0E16/cm3 to 1.0E19/cm3. For a 5000V diode, the same general guidelines for substrate doping and the amount of P-dopant still apply. It usually takes a deeper P-diffusion depth, anywhere from 30 to 90 μms, to provide sufficient P-type charge for such high voltage. Furthermore, it requires the use of single or double beveling to reduce electric field at the device periphery to sustain the desired blocking condition.
[0010] Prior art conventional devices have low ruggedness because the avalanche conditions of these devices occur in a limited area at the periphery of the active P-N junction, as shown in FIG. 1( a ). Because avalanche occurs in a limited area, and avalanche current is confined to the limited area, the ability of the device to dissipate energy under the avalanche condition without causing damage to the device is also limited.
SUMMARY OF THE INVENTION
[0011] The present invention provides a diode structure and fabrication method for achieving high ruggedness by creating an avalanche condition in a much larger portion of the active area of the device, which can be either a substantial portion of the active area or the entire active area of the device, and not just at the device periphery. The larger the participating area for avalanche, the higher the avalanche ruggedness or capability. The device active area is typically the largest feature in the device in order to conduct the high forward current while maintaining an acceptable forward voltage. It is, therefore, this same area we want to use to conduct the avalanche current in the reverse direction, as shown in FIG. 1( b ). In order to make the entire active area avalanche simultaneously, various methods can be devised. One can increase the breakdown voltage of the periphery thereby accentuating the center portion to cause a lower avalanche voltage within the active area of the device. Or one can keep the periphery unaltered and reduce the avalanche capability of the center active area. Either way, the same large area used for forward conduction is also used for dissipating energy in avalanche.
[0012] Other objects, features and advantages of the invention will become more apparent from the following detailed description, which proceeds with reference to the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] [0013]FIG. 1( a ) is a cross-sectional view of a conventional fast recovery diode (FRED) showing a principal PN junction in the center area and peripheral guard-ring PN junctions extending symmetrically from the center area toward the edge of the device. Avalanche current flow is shown by arrows as taking place at the periphery of the main PN junction.
[0014] [0014]FIG. 1( b ) is a cross-sectional view of a FRED according to the present invention. The structure shown is similar to FIG. 1( a ) for the edge protective guard-rings. However, the entire central portion of the principal PN junction participates in avalanche, as shown by arrows.
[0015] [0015]FIG. 2( a ) is a cross-sectional view of an alternative structure for a rugged FRED according to the invention showing the use of trenches followed with P-dopant introduction and diffusion to create acute curvature in the active central area of the device.
[0016] [0016]FIG. 2( b ) is a top view of one representative trench pattern for which FIG. 2( a ) can be the cross-sectional view along lines A-A′.
[0017] [0017]FIG. 3 is a cross-sectional view of yet another alternative structure for a rugged FRED according to the present invention wherein the center part of the semiconductor material is thinned down so as to force a lower breakdown voltage in the thinned region.
[0018] [0018]FIG. 4 is a graph of the relationship between breakdown voltage reduction and additional N charge for one embodiment of a rugged FRED according to the present invention.
[0019] [0019]FIG. 5 a )-d) is a series of cross-sectional views showing the key processing steps for making a rugged FRED as shown in FIG. 1( b ) according to the principle illustrated in FIG. 4.
[0020] [0020]FIG. 6 is a plot of UIS capability versus avalanche current comparing FRED devices of FIGS. 4 and 5 with prior art devices.
[0021] [0021]FIG. 7 is a graph of UIS capability test waveform for a rugged FRED made according to the process of FIG. 5.
[0022] [0022]FIG. 8( a ) is a cross-sectional view which shows application of the concept of FIG. 4 to a MOSFET device wherein the P+N junction is formed between the P-body diffusion and an N-diffusion layer.
[0023] [0023]FIG. 8( b ) shows application of the concept of FIG. 4 to an IGBT device wherein the P+N junction is formed between the deep P+ diffusion at the bottom of the trench and an N-diffusion layer.
[0024] [0024]FIG. 9 shows a simple boost circuit as an example of a circuit which utilizes a fast recovery diode.
DESCRIPTION OF THE INVENTION
[0025] Preferred Structure
[0026] [0026]FIG. 1 shows the cross-sectional views of a rugged FRED 10 (FIG. 1( b )) and a conventional FRED 9 (FIG. 1( a )) for comparison. They both have the same starting material of an N-type epitaxial layer 14 on N+ substrate 12 , the basic structure of a PN junction 16 a , 16 b in the active area 17 a , 17 b and plural guard-ring structure 18 at the device periphery. In the conventional FRED 9 , the P-diffusion depth D is generally the same for the active area and for the guard-ring area. In the rugged FRED 10 , the structure of the rugged FRED shown in FIG. 1( b ) has a second N-layer 20 (dashed line), a shallow P-diffusion layer 22 forming junction 16 b in the second N-layer 20 in the active area 17 b , and a comparatively deeper P-diffusion layer 24 in the guard-ring area. Depth arrow D 1 indicates the depth of the PN junction in the guard-ring and arrow D 2 indicates the lesser depth of the PN junction in the active area. The fact that the guard-ring PN junction is shown to be deeper is a matter of design choice and not a necessary component of the invention because shallow guard-ring diffusion when properly designed can still have a higher avalanche breakdown voltage than the active area.
[0027] An optional N-layer 26 is shown diffused into the substrate from the top surface. This layer is labeled N-layer 1 to be consistent with the process sequence in FIG. 5. The purpose of this N-layer 1 is to prevent current flow along the surface between the active area and the edge of the device due to “counter doping” of the lightly doped N-type epitaxial layer by a life-time control dopant, usually a transition metal such as gold or platinum used to increase the speed of the FRED. Counterdoping can be of particular concern for high voltage diodes which start with a very lightly doped N-type epitaxial layer. Heavy metal life-time control dopant when activated contributes a level of P-type dopant between 1.0E13/cm3 to 5.0E15/cm3 (depending on the temperature for introducing the life-time control dopant) at the surface and can cause the lightly doped N-type material to reduce its effective doping level or to be converted to P-type, thereby causing a conduction path across the surface. By using a higher doping N-layer 1 at the surface, the adverse counter-doping effect is rendered harmless.
[0028] The purpose of the N-layer 2 (diffusion 20 ) and shallow P diffusion 22 is to force avalanche breakdown to take place in the central portion of the device in the entire active area instead of just in the periphery. Since the entire active region has a much large area than the periphery of the main PN junction of the device, high avalanche energy capability is achieved by forcing avalanche breakdown to occur in this region.
[0029] [0029]FIG. 5 shows the key process steps of a rugged FRED embodying the principle illustrated in FIG. 1( b ). The fabrication process has one additional mask compared to the conventional FRED but can use the same silicon substrate 12 , 14 . Prior to field oxidation in FIG. 5( a ), the optional N-layer 1 (diffusion 26 ) is introduced such as by a blanket ion implantation into the upper semiconductor surface in a dose of 5.0E10/cm2 to 5.0E12/cm2 at an energy of 30-100 KeV. This dopant will be diffused into the substrate in subsequent thermal processes to a depth preferably slightly deeper than the guard-ring P-diffusion.
[0030] Windows 32 are opened in the field oxide 30 , as shown in FIG. 5( b ), to allow the introduction of P-dopant 24 into the guard-ring region 18 at the periphery of the device. This is usually done by implanting boron in a dose between 1E12/cm2 to 1E5/cm2 in an energy range between 40-120 KeV. The guard-ring P-dopant may be diffused to form PN junctions right after the implantation step or in conjunction with other dopants for the P and N diffusions in the active region at a later time.
[0031] The main active area window 34 is opened next as shown in FIG. 5( c ), and the N-layer 2 is implanted in a dose between 5E11/cm2 to 5E14/cm2 at an energy of 30-100 KeV and diffused into the substrate in the active region defined by window 34 to raise the N-type dopant level in the vicinity of the top surface 36 .
[0032] A PN junction 16 e in the main body of the active area 17 e is formed in FIG. 5( d ) by implanting boron at a dose of 1E12/cm2 to 1E15/cm2 with an energy between 40-120 KeV and diffused into the N-layer 2 . Doses higher than indicated can be used but devices will have higher implantation damage and higher leakage current. Therefore, high dose should be avoided.
[0033] The proper combination of doses for N Layer 2 (diffusion 20 ) and P boron body (diffusion 22 ) depends on many factors. The objective is to create an additional N charge which in turn modifies the electric field so that avalanche breakdown voltage is purposely reduced in the main body of the PN junction 16 e compared to regions without N+ layer 2 , such as in the guard-rings. It should be understood by those skilled in the art that many dose combinations are possible to accomplish the objective depending on the relative depths of the N and P diffusions 20 , 22 and the desired injection level. In a P+N junction, the injection level is controlled principally by the dose of the P+ side. The P-dopant controls the amount of excess minority carriers injected over the PN barrier into the N side during forward conduction and requires a commensurate amount of life-time control dopants to recombine in reverse recovery. Thus, for a desired recovery speed/characteristic, the higher the P-dopant level drives a proportionately higher dose of life-time control dopant. This life-time control dopant further impacts the counter-doping effect and the resultant net N charge on the N-side.
[0034] The above description of creating a higher electric field and lower breakdown voltage in the active main body area of the device by introducing an additional higher N dopant layer underneath the P diffusion to form a P-N-N − junction has the capability of the largest avalanche area on a device. The amount of additional charge generated by the higher N dopants is crucial to this concept in depressing the breakdown voltage. FIG. 4 shows the relationship between breakdown voltage reduction and the additional charge in the N region. The experimental data of breakdown voltage shown in this drawing is for a life-time control process of a 5 second ˜1015° C. RTA (rapid thermal anneal) life-time control dopant diffusion (or equivalently a 6 hour furnace diffusion at ˜910° C.). A higher life-time control process (e.g., more Pt or Au diffused in the N epitaxial layer) will shift the curve to the right in order to achieve the same breakdown voltage reduction. Obviously, the breakdown voltage decreases as additional charge is added. The introduction of additional N-type charge to reduce the breakdown voltage in the active area can also take place from the backside of the epitaxial layer such as by creating a buried N-layer in the epitaxial layer. However, this is not as convenient or cost effective as the approach described and shown in FIGS. 1 ( b ), 4 and 5 .
[0035] Alternative Methods for the Invention
[0036] Following are several alternative approaches to making rugged FREDs according to the basic principles of the present invention:
[0037] 1) FIGS. 2 ( a ) and 2 ( b ) show the alternative approach of creating trenches 136 in a matrix (or array) structure in the active area 17 c . These trenches can be interlacing stripes in the X and Y direction or arrays of circles, squares or the like wherein a height difference is first created in the top surface. The grid structure is intended to maximize the number of similar acute curvature regions thereby increasing the avalanche area and UIS capability. Spacing between trenches is adjusted in relationship to the diffusion depth so as to create the largest avalanche area possible. For shallow junction depths, the spacing can be narrow so that more trenches can be packed per unit area. Other trench patterns such as small circular trenches spaced apart and arrayed in square, rectangular or hexagonal symmetry over the active area can also be used. However, these have the disadvantage of having a smaller avalanche area and, therefore, lower UIS capability as compared to the case of FIG. 2( b ).
[0038] After forming the trench array, P-dopant 22 is next introduced at both the untrenched top surface and at the bottom of the trenches. After diffusing the P-dopant to merge with the P-dopant along the sidewalls, an acute curvature is created at corners or edges of the trenches. The trench depth 38 in this construction is no deeper than about twice the active area P-diffusion depth. For example, trench depth 38 can be 2 microns and diffusion depth about 1.5 micron. In one embodiment, the diffusion has a depth that is greater than one half the trench depth to form a PN diode wherein the P-diffusions originating at two height levels spaced apart by the depth of the trench are linked. In another embodiment, the diffusion has a depth which is shallower than one half the trench depth to create a merged Schottky-PIN structure.
[0039] The P-diffusions around the bottom corners of the trenches form areas of acute curvature having high electric field which initiates the avalanche so that the breakdown voltage in the active area 17 c becomes depressed as depicted in FIG. 2( a ). However, this structure can only induce avalanche in an area smaller than the entire active portion of the active device area thereby achieving an avalanche capability less than the optimal.
[0040] 2) Another alternative is creating substantially thinner N-type epitaxial layer in the active area than the periphery by reducing the epi thickness of the active area relative to its periphery, as shown in FIG. 3. Due to a thinner epitaxial layer remaining in the active area, a lower breakdown voltage in the center of the device than the periphery is induced. This task can be accomplished by chemically dry or wet etching a depression 40 of depth 42 in the N-type epitaxial layer in the active area 17 d . The residual thickness of the epitaxial layer 14 in the active area is 85% or less than that of the periphery. This etching is done while protecting the peripheral guard-ring area with a mask. The thinner epitaxial material causes a lower breakdown voltage to occur in the active area 17 d of the device effecting a breakdown voltage “clamping” by the active area.
[0041] 3) Another approach is improving the peripheral field spreading scheme to above the limit of “plane junction” breakdown. This can be accomplished through positive beveling, multiple deep trenches, larger radius of curvature diffusions or grooves in the peripheral on the top surface or on both surfaces of the wafer at the device periphery to increase the breakdown voltage of the peripheral region of the device thereby forcing the active region to avalanche first. In general, these methods require much more complex processing steps and larger real estate; therefore, more cost.
[0042] As implied in the above discussion, life-time control is necessary in general to control the device reverse recovery speed and recovery charge for all the methods discussed above. Prior U.S. Pat. Nos. 5,262,336 and 5,283,202, incorporated herein by reference, describe methods for improving life-time control without substantially increasing leakage current that are applicable as effective life-control methods for the present invention. It must be emphasized that the additional N dopant layer, the shallow P-diffusion and associated charges as described in the embodiment of FIG. 1( b ) above must be designed in consideration of the life-time control method used because most life-time control measures tend to modify the dopant level by compensating or counter-doping the doping level of the host material. Irradiation has the least counter-doping effect and forward voltage drop while heavy metal has the most counter-doping impact. However, Pt has been proven to have by far the lowest leakage current at elevated temperatures. Irradiation, although generally having low leakage current at room temperature, has a larger increased leakage current compared to Pt dramatically at >100° C. Heavy metal doping life-time control and irradiation may be combined to effect life-time control. However, one must bear in mind the attendant adverse leakage current associated with irradiation at higher temperatures.
[0043] Completion of the device follows normal procedure to protect the device with conducting metal electrodes 50 , 52 on the frontside and backside of the semiconductor and to provide protective insulating layer at the device surface.
[0044] The embodiments mentioned above illustrates various methods to accomplish the desired objective of achieving large area avalanche. Other methods are readily apparent to those skilled in the art without deviating from the spirit of the present invention. However, the most straight-forward method is the preferred structure. The following further summarizes how this can be achieved without altering the guard-ring design:
[0045] a) Start from an N-type substrate with appropriate background doping level for the desired blocking voltage as in prior art devices.
[0046] b) Provide the standard voltage blocking structure at the periphery of the device the same as in prior art devices. Block the active area for future processing and introduce and diffuse the first P-type dopant into the device periphery to form the first PN junctions for the periphery of the device.
[0047] c) Introduce a second N-type dopant into the entirety or large portion of the active area and diffuse to create an N-type dopant profile substantially higher than that of the background doping level.
[0048] d) Introduce a second P-type dopant into the active area and diffuse it into the higher doped second N-type layer to create a second PN junction, which has an avalanche breakdown voltage below that of the peripheral PN diode due to a higher electric field near this shallower second PN junction.
[0049] e) Apply means for life-time control to effect the desired switching speed and recovery charge.
[0050] f) Provide conductors for top and bottom electrodes and protective film against mechanical handling to complete the device.
[0051] This new FRED structure just described has a second PN junction in the active area of the device. It has a depth shallower than that of the peripheral diode. For example, the second N-type dopant has a surface concentration in the range of 1.0E15-5.0E17/cm3 and a diffusion depth of 3 to 10 urns with a companion second shallow P body layer having a diffusion depth of about 2-6 μms and a surface concentration of 1.0E16 to 5.0E18/cm3 while the periphery PN junction can be 8 ums deep with a surface concentration of 1.0E18 to 1.0E19/cm3. Again, this difference in junction depths between the main body area and the guard-ring is preferred but not necessary.
[0052] It should be pointed out that although the foregoing discussion focuses on the simplest PN junction diode for convenience. The principles described apply equally well to other types of semiconductor devices having PN junctions as integral part of the device construction. For example, MOSFET and IGBT as described in, e.g. U.S. Pat. Nos. 4,895,810 and 5,262,336 and the like teach forming PN junctions between the P-body diffusion and the N-type substrate. The inventive concept described so far can be applied to these and other types of devices as well. It should also be pointed out that the exemplary methods may be applied singly or in combination to effect large area avalanche breakdown. For example, the concept of introducing additional N charge as taught in FIGS. 4 and 5 in the preferred embodiment and the preferred embodiment in combination with the alternative method (1) of using trenches followed with implantation and diffusion have both been applied successfully to the PN structure of IGBT and MOSFET devices to produce substantially improved UIS capability through inducing avalanche breakdown simultaneous in identical structures in the device active area.
[0053] FIGS. 8 ( a ) and 8 ( b ) depict examples of such incorporation involving different PN diffusion structures associated with one representative trench of a '810 and '336 type device. The figures are each drawn for a representative structure centered around a trenched region. The actual device is made up of a large number of similar structures contiguously arranged to form the entire device. When large numbers of like structure are made to avalanche through the combination of additional N charge, trench, implant and diffusion, the UIS capability of the device to withstand high energy under avalanche is increased. To emphasize the equivalence in structures between a simple PN diode and the more complex MOSFET or IGBT structures of FIGS. 8 ( a ) and 8 ( b ), the numerical identifiers 120 and 220 are used to refer to structures equivalent to 20 for the additional N-dopant layer. Similarly 122 , 222 , 322 and 422 are identifiers for various P-type diffusions equivalent to the P-diffusion 22 in the simpler PN diode.
[0054] IGBT devices can be made to avalanche at the same locations as the MOSFET shown in FIG. 8( a ). However, the strongest UIS capability is the one illustrated here in FIG. 8( b ) in that the avalanche current has the shortest path to the cathode conductor, avoiding turning on any parasitic structure (a MOSFET has a parasitic NPN bipolar structure while an IGBT has a parasitic NPNP thyristor). It follows naturally that the concept shown in FIG. 8( b ) is applicable also to a MOSFET. In our prior U.S. Pat. Nos. 4,895,810 and 5,262,336, incorporated by this reference, we described how to form the enhanced P+ region in the trench. To lower the avalanche voltage in an IGBT, the prior art technique of forming deep P+ diffusion is combined with the procedure for introducing N+ layer 2 , as described above and shown in FIG. 5( c ), at an earlier stage of fabrication such as before gate oxidation.
[0055] Experimental Data of This Invention
[0056] 1000V, 100 A FREDs have been produced by using the preferred structure and method as described above and shown in FIGS. 1 ( b ) and 5 . FIG. 6 shows the UIS capability versus avalanche current of representative devices, and FIG. 7 shows a representative companion UIS test waveform. It is clear that this new structure and concept has produced unprecedented UIS capability.
[0057] While specific exemplary embodiments of the present invention have been shown, they are in no measure intended to be exhaustive but only serve to illustrate the inventive concept. It will be obvious to those skilled in the art that many variations and modifications will immediately become apparent. We claim all such variations and modifications as fallen within the scope of this invention.
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An improved Fast Recovery Diode comprises a main PN junction defining a central conduction region for conducting high current in a forward direction and a peripheral field spreading region surrounding the central conduction region for blocking high voltage in the reverse direction. The main PN junction has an avalanche voltage equal to or lower than an avalanche voltage of the peripheral field spreading region so substantially the entire said main PN junction participates in avalanche conduction. This rugged FRED structure can also be formed in MOSFETS, IGBTS and the like.
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This invention relates generally to automatic test equipment for semiconductors and more specifically to a semiconductor tester having small size and low cost achieved through the use of chips with high channel density.
During their manufacture, most semiconductor devices are tested at least once using some form of automated test equipment (generally, a "tester"). Modem semiconductor chips have numerous leads and, to fully test the semiconductor device, the tester must generate and measure signals for all of these leads simultaneously.
Modern testers generally have a "per-pin" architecture. A "pin" is circuitry within the tester that generates or measures one signal for the device under test. A "pin" is sometimes also called a "channel." In a per-pin architecture, each channel can be separately controlled to generate or measure a different signal. As a result, there are many channels inside one tester. The channels are controlled by a pattern generator. The main function of the pattern generator is to send commands to each channel to program it to generate or measure one test signal for each period of tester operation.
Each channel generally contains several edge generators, a driver/comparator and some format circuitry. Each edge generator is programmed to generate an edge signal (or more simply an "edge") at a certain time relative to the start of each period. The format circuitry receives digital commands from the pattern generator indicating what signal should be generated or measured during a period. Based on this information, the formatter combines the edges into on and off commands for the driver/comparator. In this way, the driver and comparator measures or generates the correct valued signal at the correct time.
Each edge generator is in turn made up of two basic pieces. It has a counter and a interpolator, each of which is programmable. The counter is clocked by a system clock. It is programmed to count some number of periods of the system clock. It is triggered to start counting at the start of a tester period. In general, the period of the system clock will be much smaller than the tester period so that the timing of edges within a tester period can be controlled fairly accurately simply by counting system clocks.
However, if the time of the edge is determined solely by counting system clocks, the resolution with which the edge can be generated is the same as the period of the system clock. For testing many semiconductor components, this resolution is not fine enough. The interpolator is used to provide finer time resolution.
The interpolator delays the output of the counter by a programmable amount that is smaller than one period of the system clock. Thus, the resolution with which timing edges can be generated is limited by the resolution of the interpolator, rather than the period of the system clock.
One difficulty with having a interpolator that provides a delay smaller than the period of the system clock is that signals propagating through the interpolator can not be clocked relative to the system clock. In digital systems, the effects of timing inaccuracies and many other error sources are often eliminated by clocking signals to a reference clock.
The fact that the interpolators are not clocked creates a particular problem in testers when the channels are placed close together. Other signals within the tester can influence the signals in the other interpolators. This influence is called "cross talk." If the cross talk is too great, erroneous outputs are generated by the tester. A major source of cross talk is "channel to channel cross talk". If signals in one channel switch about the time that an interpolator is producing an output, transient signals generated by the switching of the signals cause the interpolator output to fluctuate. If the fluctuation increases the interpolator output, the timing edge occurs earlier than intended. If the fluctuation decreases the interpolator output, the timing edge occurs later than intended. In this way, cross talk reduces accuracy of the timing edges.
Cross talk is also created by the interference of signals going to the multiple timing generators within each channel. However, cross talk is worst when a signal switches roughly at the time that an interpolator is producing a timing edge. The interpolators within a channel are generally programmed to produce edges at times that are different enough that the cross talk does not influence the time of the timing edge produced by the interpolator.
We have recognized that channel to channel cross talk is worse than "intra-channel cross talk. For that reason, cross talk gets worse as the channels are placed closer together. One prior art way to eliminate the effects of cross talk is to keep the channels spaced apart.
The channels are manufactured on integrated circuit chips. Heretofore, a separate integrated circuit chip has been used to hold each channel. We have recognized that cross talk between channels, when made on the same integrated circuit chip, prevented each channel from operating with the required accuracy. As will be described in greater detail below, we have invented a way to manufacture integrated circuit chips for a semiconductor test system containing multiple channels.
We are able to achieve tremendous advantages by incorporating multiple channels into one chip in an integrated circuit test system. It reduces the overall size of the test system while allowing it to test modern semiconductor devices with large numbers of leads. The size of a test system is very important to semiconductor manufacturers. Semiconductors are often tested in "clean rooms." A clean room has expensive filtering systems to keep dust and other impurities from corrupting the semiconductor devices, particularly before they are encased in a package. Each square foot of clean room space is very expensive to build and operate. It is thus highly desirable to limit the size of equipment that is placed in a clean room.
A further advantage we have achieved by reducing the number of integrated circuit chips to carry the channels in a test system is one of cost. The cost of the silicon occupied by the circuitry inside an integrated circuit represents a small fraction of the overall cost of the device. Packaging the silicon, building a circuit board to hold the device, building a frame to hold the printed circuit boards all add substantial costs to the finished product. All of these costs increase with the number of integrated circuit chips.
Despite the tremendous advantages that are obtained by incorporating multiple channels into one integrated circuit chip, testers heretofore have not be able to achieve these advantages.
SUMMARY OF THE INVENTION
With the foregoing background in mind, it is an object of the invention to provide a low cost tester.
It is also an objective to provide a small tester.
It is a further objective to provide a small and low cost tester with very low cross talk between channels.
The foregoing and other objects are achieved in a tester having pin electronics implemented with integrated circuit chips. Multiple channels are built on each integrated circuit chip. The integrated circuit chips include cross talk suppression mechanisms to allow the required accuracy.
In a preferred embodiment, there are four channels on each integrated circuit chip. In one embodiment the cross talk suppression mechanism is an interpolator circuit designs having high power supply rejection. In another embodiment, it is the use of separate power and ground routes for each channel. In another embodiment, the suppression mechanism is separate hold capacitors for each interpolator. In yet further embodiments, the suppression mechanism is the use of an guard ring around each interpolator with a separate ground connection for each guard ring. In another embodiment, it is kelvin connection of each power and ground to chip pads.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be better understood by reference to the following more detailed description and accompanying drawings in which
FIG. 1 is a sketch illustrating the architecture of a semiconductor tester;
FIG. 2A is a simplified schematic of one timing edge generator in a test system of the invention;
FIG. 2B is a simplified schematic of control circuitry shown in FIG. 2A;
FIG. 2C is a simplified schematic of the fine delay and current control circuitry in FIG. 2A;
FIG. 2D is a simplified schematic of the alignment delay circuitry in FIG. 2A;
FIG. 2E is a simplified schematic of the delay stage circuitry of FIG. 2A;
FIG. 3 is block diagram illustrating power, ground and shielding connection of multiple timing generators on a single integrated circuit chip;
FIG. 4 is a simplified diagram illustrating implementation of edge generator shielding for multiple edge generators within a channel.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows a tester 100 in simplified block diagram form. Tester 100 is controlled by a test system controller 110. Test system controller 110 generates digital control values for each channel of tester 100. The digital control values specify such things as when each channel should generate or measure a test signal, the value that should be generated and the format for that test signal.
Control information is provided for each cycle during which the tester operates. The data needed to specify what signals each channel should be generating or measuring for every cycle during a test is sometimes called a pattern. The pattern is stored in memory 120.
In addition to providing digital control values, test system controller 110 provides a timing signal that identifies that start of each tester cycle. This timing signal is sometimes called "T0" or "Beginning of Period" (BOP). Other parts of the tester that operate on a per cycle basis are triggered by the T0 signal.
The digital control values, as well as the T0 signal, are provided to a plurality of channels 114. A typical tester has between 64 and 1024 channels. However, the number of channels is not important to the invention. Each channel generally contains the same circuitry.
Within each channel 114 are a plurality of timing generators 116. Each timing generator 116 generates a timing edge that controls the time of an event within tester 100. The events might be such things as the start of a test pulse applied to a device under test 112 or the end of the test pulse. An edge might also be used to trigger measurement of a signal from device under test 112.
The time at which a timing edge should occur is specified relative to the start of the cycle. The timing data therefore indicates the amount of delay after the T0 signal when the timing edge is to be generated. In a preferred embodiment, the timing information is specified by several groups of data bits, each group of bits representing time periods of finer and finer resolution. The most significant group of bits represents delay as an integer number of periods of a system clock. The amount of delay specified by the most significant group of bits can be easily generated by counting an integer number of pulses of the system clock. The next most significant group of bits represents delay in intervals that are some fraction of the system clock. These bits are sometimes called the "fractional portion" of the timing data. This delay must be generated by an interpolator.
The timing edges from all of the timing generators 116 within a single channel are passed to a formatter 118. In addition to receiving timing edges, formatter 118 also receives other control information form test system controller 110. This control information might indicate the value of the test signal to be generated during a period, i.e. a logical 1 or a logical 0. It might specify other things such as the format of the signal applied to device under test 112. For example, formats such as "return to zero," "surround by complement," "return to one," and "non-return to zero" are all sometimes used. These formats might be imposed by formatter 118.
FIG. 1 shows a test system architecture that illustrates the role of timing generators 116. Other architectures are possible. The specific source of control information for the timing generators 116 and the specific use of the timing edges they generate is not critical to the invention.
Turning now to FIG. 2A, the circuitry of a timing generator 116 according to the invention is shown. Digital timing data from test system controller 110 is applied to timing generator 116. Timing generator 116 then produces a timing edge that is used by formatter 118 (FIG. 1) or elsewhere in the tester.
A digital delay line 210 is shown. The delay line is a preferably a CMOS delay line and more preferably a differential delay line. The stages of the delay line are shown in more detail in conjunction with FIG. 2E, below.
FIG. 2A shows that 16 delay stages 212(1) . . . 212(16) are cascaded in delay line 210. The input to delay line 210 is derived from a system clock, which is shown as a differential clock on lines CLOCKP and CLOCKN. Before application to delay line 210, the system clock is conditioned in delay stage 212(0). More than one delay stage could be used for conditioning. Delay stage 212(0) is like the other stages in delay line 210. In this way, the input of every delay stage 212(1) . . . 212(16) in delay line 210 receives an input signal from the same kind of circuitry. All of the delay stages 212(1) . . . 212(16) therefore receive inputs with the same voltage swing, which leads to less variation in delay from stage to stage.
In a preferred embodiment, the system clock has a frequency of 100 MHz. However, the frequency of the system clock is not critical to the invention and could even be variable. The system clock is preferably a highly stable clock and is routed to all timing generators 116 in tester 100.
The input and the output of delay line 210 are fed to phase detector 214 through differential to single ended buffer amplifiers 237(1) and 237(2), respectively. The output of phase detector 214 is fed to control circuit 216. Control circuit 216 produces control signals that are fed back to a control input, VC, in each delay stage 212. The control signal adjusts the delay through each delay stage 212. Delay line 210, phase detector 214 and control circuit 216 implement what is known as a Delay Locked Loop. The loop is said to be "locked" when the delay through delay line 210 equals one period of the system clock. In the embodiment of FIG. 2A, that results in each delay stage delaying the system clock by one sixteenth of a period of the system clock.
Phase detector 214 is as conventionally found in a delay locked loop. Control circuit 216 is similar to a charge pump as used in a conventional delay locked loop. However, it has been modified, as is explained below, to reduce the cross talk between interpolators.
The output DO of each delay stage 212 is fed to a differential multiplexer 220. Multiplexer 220 selects the output of one of delay stages 212 as specified by certain bits of the timing data. In FIG. 2A, bits 4-7 represent the high order bits of the fractional portion of the timing data. Because the outputs of delay stages 212 are delayed by one sixteenth of the period of the system clock, the output of multiplexer 220 provides a clock signal that has been delayed by a multiple of one sixteenth of the system clock period.
To get finer resolution on the delay, the output of multiplexer 220 is passed to a fine delay circuit 222. Fine delay circuit 222 is controlled by bits 0-3 of the timing data. Bits 0-3 represent an additional delay that is a multiple of 1/256 of a period of the system clock. The operation of fine delay circuit 222 is described in greater detail in conjunction with FIG. 2C, below.
To provide greater accuracy, a current control circuit 224 is used in conjunction with fine delay circuit 222. The operation of current control circuit 224 is described below in conjunction with FIG. 2C. Current control circuit 224 receives a control input from a calibration register 226. As is known in the art, a tester is calibrated by programming a tester to generate a test signal at a specific time. The actual time at which the test signal is generated is measured to determine the difference between the desired time and the actual time at which the tester generates signals. Calibration values might be computed from this information. Alternatively, the calibration values are adjusted until the tester actually produces a test signal at the desired time and the calibration values that produces the desired result is stored. The contents of calibration register 226 is determined using a calibration process.
The output of fine delay 222 is a differential signal representing a delayed version of the system clock. It is delayed by a fraction of a period of the system clock. The delay is some multiple of 1/256 of the system clock period. The differential signal is applied to a differential to single ended converter 228. The output of differential to single ended converter 228 is applied to a gating circuit 230.
The input to gating circuit 230 is a clock signal, i.e. a train of pulses that occur at periodic intervals. It has merely been delayed relative to the system clock a programmed amount. To make a timing edge, one of the pulses must be selected. Gating circuit 230 selects the desired pulse to generate the required edge. Alignment delay circuit 234 provides a control signal that specifies which of the pulses is passed by gating circuit 230 to generate a timing edge at the appropriate time.
Alignment delay circuit 234 is described in greater detail in conjunction with FIG. 2D, below. Suffice it to say here that counter 236 receives the most significant bits, or integer portion, of the timing data. Counter 236 is reset by the T0 or beginning of cycle signal and then counts pulses of the system clock until the desired number of periods of the system clock has passed. When the required integer number of periods of the system clock has passed, counter 236 produces a terminal count signal that goes to alignment delay 234. Alignment delay 234 also receives as inputs bits 4-7 of the timing data and outputs from delay stages 212. The outputs of delay stages 212(1) . . . 212(16) are converted to single ended signals by differential to single ended converters 238(1) . . . 238(16). This information allows alignment delay circuit 234 to generate a control signal that enables gating circuit 230 to pass the desired pulse from the train of pulses produced by fine delay 222. Gating circuits that can pass a selected pulse from a pulse train are known in the art and need not be further described.
Turning to FIG. 2E, details of a representative one of the delay stages 212(0) . . . 212(16) are shown. The terminals labeled IN+ and IN- represent a single differential input signal. The terminals labeled OUT+ and OUT- represent a single differential output signal. For delay stages 212(0) . . . 212(16), the terminals IN+ and IN- are connected to the terminals OUT+ and OUT-, respectively, of the preceding stage in the chain of delay stages as well as to a differential to single ended converter. For stage 212(0) the terminals IN+ and IN- are connected to the system clock as shown in FIG. 2A. For stage 212(16), the terminals OUT+ and OUT- are connected to differential to single ended converter 237(2) and to a dummy delay cell 212(17) as shown in FIG. 2A. The only purpose of 212(17) is to insure that 212(16) has the same loading as all of the preceding stages.
The input signal IN+ and IN- are applied to differential pair of transistors 280 and 281. Current in delay stage 212 is controlled by control signal VC1, which is derived from control circuit 216 in a manner described below in conjunction with FIG. 2B.
Transistors 283 and 284 act as loads for the differential pair of transistors 280 and 281. Transistors 285 and 286, which are connected in parallel with load transistors 283 and 284, are controlled by a control signal VC2, which is also derived from control circuit 216, as described below in conjunction with FIG. 2B.
Transistors 285 and 286 provide control over the voltage swing at terminals OUT+ and OUT- to ensure that the output signal has sufficient swing as the delay through delay stage 212 is adjusted by control signal VC1. As control signal VC1 decreases, the current through the delay cell decreases. Without transistors 285 and 286, a decrease in current would decrease the voltage drop across transistors 283 and 284. The decrease in voltage gives terminals OUT+ and OUT- a quiescent voltage that is closer to V DD . Because the voltage at OUT+ and OUT- can never swing above V DD , a quiescent voltage closer to V DD reduces the swing.
Therefore, as control signal VC1 decreases, control signal VC2 should increase, thereby tending to keep the quiescent voltage at OUT+ and OUT- reasonably constant. The swing at the outputs OUT+ and OUT- is therefore maintained over a wide range of values for VC1.
Transistors 288 and 289, in conjunction with transistor 287 buffer the signals at terminals OUT+ and OUT- so that they can interface with multiplexer 220 (FIG. 2A). The drains of transistors 288 and 289 are current mode connections to an input of multiplexer 220. Transistor 287 regulates current through those transistors in response to a control signal VC1.
Turning now to FIG. 2B, details of control circuit 216 are shown. Control circuit 216 includes charge pump 250 as is conventional in a prior art delay locked loop. The output of the charge pump is connected to capacitor 252. In a conventional delay locked loop, the other end of capacitor 252 is connected to ground to form what is essentially a low pass filter.
In control circuit 216, the other end of capacitor 252 is connected to V DD , the voltage supply. To drive a control signal from the phase detector circuit, the control circuitry includes derivation logic in the form of a transistor network comprising transistors 254, 256, 258 and 259. The source terminal of transistor 254 is connected in parallel with capacitor 252. An "UP" signal from phase detector 214 indicates that the delay line 210 is running too fast. Charge pump 250 raises the output voltage in response to the "UP" signal from phase detector 214, which reduces the voltage drop across capacitor 252. Thus, the gate to source voltage of transistor 254 decreases the source current of transistor 254.
A "DOWN" signal from phase detector 214 has the opposite effect on the source current of transistor 254. Thus, the source current of transistor 254 indicates whether the delay through delay line 210 must be increased or decreased.
Transistor 256 is connected in series with transistor 254. As the source current increases in transistor 254, the drain to source current increases an equal amount in transistor 256. As the current flow in transistor 256 increases, the gate to source voltage of transistor 256 also increases. Thus, the gate to source voltage of transistor 156 is proportional to the voltage across capacitor 252. Because the voltage across capacitor 252 indicates whether the delay through delay line 210 (FIG. 2A) should be increased or decreased, the gate to source voltage of transistor 256 represents a signal that is proportional to the required adjustment of delay and is denoted VC1, which, as described above, is one element of the signal VC that controls delay through each of the delay stages 212 (FIG. 2A).
The second element of control signal VC is signal VC2, and is also generated by the circuitry shown in FIG. 2B. Transistors 257, 258 and 259 collectively make up a control signal mirror that develops a signal VC2 from VC1. The gate and drain of transistor 257 is tied to VC1. This point is tied to the gate of transistor 258, which ensures that the gate of transistor 258 tracks the level of signal VC1. The current through transistor 258 is therefore proportional to signal VC1. As transistor 259 is configured in series with transistor 258, its current likewise is proportional to VC1.
Transistor 259 has its gate and source tied together. Thus, as the signal VC1 increases and the current through transistor 259 increases, the voltage across transistor 259 increases and the source voltage, labeled VC2, decreases. With this configuration, the signal VC2 drops as VC1 increases, providing the desired relationship between the signals that make up control signal VC.
An important aspect of the signal VC is that, though it is related to the voltage across capacitor 252, it is largely independent of the actual value of V DD . If V DD changes, the gate to drain voltage of transistor 254 will stay the same and the current through transistors 254 and 256 will likewise remain unchanged. Because the current flow through the transistors is what dictates the level of the control signal VC, the control signal is isolated from fluctuations in the value of V DD .
This design provides reduced cross talk in comparison to the prior art. One way that transient signals cause cross talk is by creating fluctuations in V DD . If the control signal of the delay locked loop is sensitive to changes in the value of V DD , fluctuations in V DD create unintended changes in control signal, leading to timing inaccuracies. The timing inaccuracies are particularly bad if, for example, changes in V DD are actually used as a control signal to adjust delay. Control circuit 216 reduces cross talk by making the control signal VC independent of V DD .
Turning to FIG. 2C, fine delay 222 is shown in greater detail. The differential output of multiplexer 220 (FIG. 2A) is applied to a differential buffer amplifier 260. The output of differential buffer amplifier 260 is applied as the input to differential to single ended converter 228.
The output of differential buffer amplifier 260 also has a series of pairs of capacitors switchably connected to it. The switchably connected capacitors form a variable load that can be used to control the switching speed of differential buffer amplifier 260 and thereby control the delay through fine delay circuit 222.
The capacitors are denoted 1C, 2C, 4C and 8C. The capacitors are sized in accordance with their numbers. Capacitor 2C is twice as large as capacitor 1C. Capacitor 4C is four times as large as capacitor 1C. Capacitor 8C is eight times as large as capacitor 1C. In a preferred embodiment, the sizing of the capacitors is achieved by simply using multiple capacitors to make larger capacitors. For example, 2 capacitors are used to make capacitor 2C and eight capacitors are used to make capacitor 8C.
The capacitors are implemented in pairs, with one capacitor of each size switchably connected to each of the inverted and non-inverted output of differential buffer amplifier 260. This configuration ensures that, upon a signal transition on the output of differential buffer amplifier 260, a constant capacitive load will be present regardless of whether the output is transitioning from a logic high to a logic low or from a logic low to a logic high.
The switches, denoted x1, x2, x4 and x8, that connect each of the capacitors 1C, 2C, 4C and 8C can be simply implemented as switching transistors. The size of the switching transistors is adjusted so that the resistance of the switch varies in inverse proportion to the size of the capacitor to which it is connected. With this ratio of resistors and capacitors, the RC time constant associated with each capacitor/switch pair is the same. Thus, the change in delay introduced when a capacitor is switched to the output of differential buffer amplifier 260 depends only on the size of the capacitors 1C, 2C, 4C or 8C and not on the RC time constant of the circuit. Switches X1, X2, X4 and X8 can be implemented by wiring multiple switching transistors in parallel. Two transistors are used to make switch X2 and eight transistors are used to make switch X8.
The size of the resistors x1, x2, x4 and x8 and capacitors C1, C2, C4 and C8 is selected such that, when all four pairs of capacitors is switched to the output of differential buffer amplifier 260, the delay through fine delay 222 increases by one sixteenth of a period of the system clock. Thus, when just capacitors 1C are switched in, the delay should increase by 1/256 of the system clock period. The computation of resistance and capacitance values need not be exact if well known calibration and software correction techniques are employed.
The switches x1, x2, x4 and x8 are controlled by bits 0-3 of the timing data. In the described embodiment these bits indicate the amount of delay fine delay 222 should add in increments of 1/256 of a system clock period. With the appropriate sized capacitors, this result is achieved by having Bit 0 control the switch to capacitor 1C, Bit 1 control the switch to capacitor 2C, Bit 2 control the switch to capacitor 4C and Bit 3 control the switch to capacitor 8C.
FIG. 2C also shows details of current control circuit 224. Current control circuit 224 adjusts for variations in the switching speed of differential buffer amplifier 260 or differential to single ended converter 228. The speed of these circuits might change as a result in changes in ambient temperature or changes in on-chip temperature caused by power dissipation in the integrated circuit on which fine delay circuit 222 is implemented. Current control circuit 224 is needed specifically because fine delay stage 224 is not identical to delay stages 212 (FIG. 2B). Fine delay stage 224, because it is intended to make a fine delay adjustment, will have different delay characteristics than the delay stages 212 (FIG. 2B).
Current control circuit 224 operates on control signal VC1. Control signal VC1 is generated based on the propagation delay through delay line 210 (FIG. 2A). In particular, it is based on deviations of the delay from the designed value. Thus, if the circuits on the chip which contains delay line 210 and fine delay 222 have a delay that is different than the designed value, VC1 will have a value that is proportional to the difference. Thus, as the delay through the circuits on the chip changes, VC1 will also change. It is these changes in VC1 in response to changes in delay that allow VC1 to be used to adjust the delay in delay stages 212(1) . . . 212(16) to have the required delay in each stage.
Though the delay through fine delay 222 is not the same as the delay through any of the delay stages 212(1) . . . 212(16), the need for delay adjustment in fine delay 222 can be correlated through a calibration process to the required amount of adjustment in delay stages 212(1) . . . 212(16). Thus, control signal VC can not be used to control the delay in fine delay 222 but can be used in determining an appropriate control signal. Current control 224 determines the appropriate control signal from control signal VC based on a calibration value stored in calibration register 226.
Differential buffer amplifier 260 and differential to single ended converter 228 are implemented using a differential pair of transistors connected in a common source configuration. By controlling the combined current flow out the sources of the differential pairs, the switching speed, and therefore the delay, of differential buffer amplifier 260 and differential to single ended converter 228 can be regulated. Current control 224 is connected to the common source terminal of the differential pairs and therefore regulates the delay of fine delay 222.
To provide the required current, control signal VC1 is applied through a series of switches 264A . . . 264D to the gate terminals of transistors 262B . . . 262E. When a switch 264A . . . 264D is closed, the drain to source current through the associated transistor 262B . . . 262E, respectively, will vary in response to changes in control signal VC1. Transistor 262A is connected to VC1 without an intervening switch and always responds to changes in VC1.
The drains of all of the transistors 262A . . . 262E are tied together and connected to the common sources of the differential pair within differential buffer amplifier 260. The total current flowing through the differential pair equals the total current flow through the ones of transistors 262A . . . 262E that are connected to control signal VC1 through a respective switch 264A . . . 264D.
The current flow through the differential pair of differential buffer amplifier 260 and differential to single ended converter 228 is thus proportional to control signal VC1, but the constant of proportionality can be adjusted by selectively closing some or all of the switches 264A . . . 264D. Because the switches are controlled by the value in calibration register 226, the value in calibration register 226 is therefore controlling the gain of the correction factor for delay in fine delay 222. Thus, as long as the delays in delay line 210 (FIG. 2A) and fine delay 222 are linearly correlated, which is true to a close approximation of circuits made on the same integrated circuit chip, differences in circuit design, layout or other factors that might prevent a single control signal from being used to control the delays in each can be used. Any errors that are introduced by using the same control signal to adjust the delay in delay line 210 and fine delay 222 can be corrected through a calibration process in which an appropriate value for calibration register 226 is determined.
In the preferred embodiment, transistors 262B . . . 262E are sized to provide different current gains. The gains are binary weighted to correspond to the bit positions in cal register 226. As shown in the figure, transistor 262C has a gain that is twice that of transistor 262B; 262D has a gain of 4 times 262B and 262E has a gain of 8 times 262B. The net effect of this weighting is to effectively multiply the control signal VC1 by the value in the calibration register 226. The value in calibration register 226 is selected through the calibration measurement process to provide the required delay through fine delay stage 222.
Because transistor 262A is set to be always on, it adds a fixed offset to the control current into differential amplifier 260. In a preferred embodiment, transistor 262A is sized to have a current gain that is approximately 3 times transistor 262B. Fine delay stage 222 and transistor 262A are designed such that, with all switches 264A . . . 264D open, the delay through fine delay stage 222 is slightly slower than the required delay of fine delay 222. Simulation or experimentation might be required to determine the correct sizes of the components. In a preferred embodiment, transistor 262B has a gain which is about one sixteenth the size of transistor 256 (FIG. 2B).
The delay through differential to single ended amplifier 228 can also be controlled by VC1. VC1 is connected to the gate of transistor 262F, which then regulates current through amplifier 228.
Turning now to FIG. 2D, details of alignment delay circuit 234 are shown. Alignment delay 234 has two identical units 270A and 270B. Units 270A and 270B generate a gating signal for successive cycles of the tester operation. Router circuit 272 directs control information to the appropriate one of the units 270A or 270B and gets the gating signal from the appropriate unit during each tester cycle. Router circuit 272 is thus just a simple switching circuit that alternates between the units each tester cycle.
Because units 270A and 270B are identical, details of only unit 270A are shown. For each cycle in which unit 270A is the active unit, it outputs a gating signal that is roughly centered around the pulse at the output of fine delay 222 (FIG. 2A) that represents the desired timing edge. In the preferred embodiment, the system clock has a period of 10 nanosecond. The gating signal has a duration of approximately 5 nanoseconds. In this way, just a single clock pulse is selected to provide the edge output of timing generator 116.
Unit 270A is made of a chain of flip-flops 274A . . . 274K. The input to the chain comes from counter 236 (FIG. 2A), routed through router circuitry 272. Until counter 236 counts the required delay in integer number of periods of the system clock, there is no output of unit 270A.
Each of the flip flops 274A . . . 274K is clocked by an output of a delay stage 212(1) . . . 212(16) (FIG. 2A). Because the accuracy of differential signals is not required in alignment delay 234, these outputs are converted to single ended signals by differential to single ended converters 238(1) . . . 238(16) (FIG. 2A). It is not necessary that outputs of all delay stages 212(1) . . . 212(16) be routed to alignment delay circuit 234. As will be described below, only the output of every other delay stage 212(1) . . . 212(16) is used by alignment delay 234. Thus, of the 16 possible outputs of delay line 210, only 8 are routed to alignment delay 234.
The clock input to flip flop 274A is connected to the signal from one of the delay stage 212(n). The clock input to flip flop 274B is connected to the signal from delay stage 212(n+2). Connections are made in this pattern to each subsequent flip flop until the delay from stage 212(16) is assigned to one of the flip flops. The pattern then wraps around, with the next flip flop, being connected to the output of delay stage 212(2). The value of n is chosen such that the delay from the start of delay line 210 (FIG. 2A) to delay stage 212(n) roughly equals the propagation delay from counter 236 to the input of flip flop 274A.
Because each delay stage 212(1) . . . 212(16) delays the system clock by 1/16 of the period of the system clock, which is 0.625 nanoseconds in the example, the time difference between the signals that clock adjacent flip flops in the chain 274A . . . 274K is 1.25 nanoseconds. Thus, when a terminal count signal is generated by counter 236, the output of each flip flop in the chain 274A . . . 274K goes high at a time that increases in successive increments of 1.25 nanoseconds. In the preferred embodiment, the terminal count signal from counter 236 stays high for 10 nanoseconds. Thus, when counter 236 has counted to introduce the required delay, a series of 10 nanosecond pulses, spaced apart by 1.25 nanoseconds is generated by the chain of flip flops 274A . . . 274K. Two of these signals are selected to form the appropriate gating signal.
AND gates 276(0) . . . 276(7) each combine the outputs of two of the flip flops in the chain 274A . . . 274K. The flip flops combined by each of the AND gates 276(0) . . . 276(7) are selected to be spaced apart by four flip flops. Thus, the inputs to AND gate 276(0) are derived from flip flops 274A and 274D. The inputs to AND gate 276(1) are derived from flip flops 274B and 274E. The inputs to the remaining AND gates are selected according to this pattern.
Because the inputs to each of the AND gates 276(0) . . . 276(7) are spaced apart by four flip flops, and the delay between the pulses produced by each flip flop is 1.25 nanoseconds, the delay between the two inputs to each of the AND gates 276(0) . . . 276(7) is 5 nanoseconds. Each input pulse is 10 nanoseconds wide. With a relative delay of 5 nanoseconds between pulses, the overlap of the two pulses is approximately 5 nanoseconds. Thus, the output of each AND gate 276(0) . . . 276(7) is a pulse that is 5 nanoseconds wide. Each pulse is delayed relative to the preceding pulse by 1.25 nanoseconds.
The output of one of the AND gates 276(0) . . . 276(7) will be a pulse that is 5 nanoseconds wide, roughly centered around the required pulse at the output of fine delay 222 (FIG. 2A). Which of the outputs is the appropriate gating signal depends on which delay stage 212(1) . . . 212(16) was selected by multiplexer 220. If the output of delay stage 212(1) or 212(2) is selected by multiplexer 220, then the output of AND gate 276(0) is the appropriate signal. If the output of delay stage 212(3) or 212(4) is selected, then the output of AND gate 276(1) is the appropriate signal. The mapping continues in this pattern, with the output of AND gate 276(7) representing the appropriate gating signal when delay stage 212(15) or 212(16) is selected.
With this pattern, the timing bits that control the selection of an output of one of the delay stages 212(1) . . . 212(16) also dictate which of the AND gates 276(0) . . . 276(7) is to be selected. Multiplexer 278 selects the appropriate output of the AND gates 276(0) . . . 276(7) based on the same timing bits. However, because the output of one AND gate is used to generate the appropriate gating signal for either of two delay stages, the lower order bit that is used to control multiplexer 220 is not needed to control multiplexer 278. Thus, FIG. 2D shows that timing bits 5-7 are applied to router circuit 272 and are then applied to multiplexer 278.
The output of multiplexer 278 is provided to router circuit 272. Router circuit 272 passes this signal through to its output and it is used as the gating signal for gating circuit 230. The falling edge of the signal out of multiplexer 278 also indicates that the required edge has been generated. Thus, unit 270A is no longer needed for that cycle of tester operation. Upon recognizing the falling edge, router circuit switches to unit 270B as the active unit. The falling edge of the output of multiplexer 278 can also be used for other purposes within timing generator 116. For example, timing data bits 0-7 should stay constant until that falling edge occurs. Therefore, the falling edge can be used to trigger a change in timing bits 0-7 from one cycle to the next.
Two units are 270A and 270B are used to allow a lower "refire recovery time." The refire recovery time indicates the minimum time difference that can be specified between consecutive edges from the same timing generator 116. In the preferred embodiment, with a 100 MHz system clock, the refire recovery time is less than 10 nanoseconds, or less than the period of the system clock. A low refire recovery time is important to allow highly flexible programmimng of test signal timing. If the refire recovery time is longer than one period of the system clock, there can be some settings for the length of a tester cycle in which an edge generator 116 might not be able to fire during each tester cycle. If the tester cycle length is set to its smallest value, that would, for the examples given herein, result in a tester cycle of 10 nsec. If the refire recovery time is longer than 10 nsec, that means if an edge generator produces an edge in one cycle, it will not be able to produce an edge in the next cycle. Shortening the refire recovery time greatly improves the flexibility of the tester.
With the embodiment of FIG. 2D, unit 270A generates the gating signal in one cycle. Unit 270B generates the gating signal in the next cycle. Thus, the refire recovery time is dictated by the time difference that has to pass between the time that unit 270A can generate a gating signal and unit 270B can generate a gating signal. In the preferred embodiment, the gating signals generated by units 270A and 270B are each 5 nanoseconds wide and centered around the programmed timing edge.
The refire recovery time might be made smaller by decreasing the time between the generation of the gating signals. However, it must be noted that the outputs of delay stages 212(1) . . . 212(16) are delay regulated through the use of a feedback signal VC. They are relatively insensitive to variations in temperature or other factors that might alter the delay through the circuitry of the timing generator. There is no such delay regulation in alignment delay 234. As a result, the relative time differences between the signals out of fine delay 222 and alignment delay 234 might vary by some small amount. For that reason, each gating signal is made, for the numerical examples given herein, 5 nanoseconds wide.
In addition, there is a need for the output of fine delay 222 to come to steady state after a change in timing data. In a preferred embodiment, this takes a maximum of 5 nanoseconds. Thus, it is necessary that the end of one gating signal and the start of the next gating signal be separated in time by at least this settling time. By combining these numbers, the resultant refire recovery time comes to a maximum 10 nanoseconds in the preferred embodiment.
It should be noted that control signal VC could also be used to regulate the delay through alignment delay 234 in a similar fashion to the way it is used to regulate delay through fine delay 222 or delay stages 212. The width of each gating pulse could then be made smaller by ANDing together in AND gates 276(0) . . . 276(7) outputs of flip flops that have a close spacing than is shown in FIG. 2D.
Turning now to FIG. 3, implementation on a single integrated circuit chip of timing generators 116 for a plurality of channels 114 (FIG. 1) is illustrated. FIG. 3 shows a portion of an integrated circuit chip 300 to schematically illustrate the placement of circuitry on the chip. In a preferred embodiment, chip 300 is a CMOS chip implemented using standard design techniques. In the preferred embodiment, chip 300 has a die size of 14.5 mm square.
A plurality of interpolators, such as 116 (FIG. 2A) are fabricated on chip 300. In the preferred embodiment, interpolators for four channels are implemented on chip 300. A test system might include many such chips so that numerous channels are provided within the test system. In the preferred embodiment, there are eight interpolators 116A . . . 116H per channel. The entire circuitry of FIG. 2A is repeated for each interpolator, with the exception of cal register 226, which, in the preferred embodiment, is repeated once for each channel.
Control circuitry 310 represents the digital circuitry needed to control the interpolators and is conventional circuitry. Counter 236 and alignment delay 234 are all part of this control circuitry 310.
The interpolators 116A . . . 116H for a single channel are enclosed within a guard ring 318. Guard ring 318 prevent signals from interpolators in one channel from interfering with the interpolators in another channel. It therefore reduces inter-channel cross talk. Each interpolator is surrounded by a guard ring 316A . . . 316H. These guard rings reduce intra channel cross talk. Fabrication of guard rings is described in greater detail in conjunction with FIG. 4, below. Guard rings 318 and 316A . . . 316H also prevent interference generated by digital control circuitry 310 from reaching interpolators 116A . . . 116H
Each interpolator 116A . . . 116H has its own capacitor 252A . . . 252H associated with it. We have found that, where all interpolators within a channel share a single capacitor, delay line 210, phase detector 214 and control circuit 216, greater cross talk resulted. Therefore, significantly less cross talk results from using a separate capacitor, delay line and associated control circuitry for each interpolator.
FIG. 3 also illustrates that separate ground, isolation and power connections are used for each channel. Isolation I/O pads 312 make connection to guard rings 318 or 316A . . . 316H. Further, the ground, isolation and power lines are kelvin connected to I/O pads of chip 300. In particular, ground and power connections are routed through individual traces to the I/O pads 312, 312 and 314. Using separate traces reduces cross coupling between the circuits that are connected through those traces. Where two circuits share a common line though which current flows, such as power or ground, current flow along the common line creates a voltage drop across the line. Changes in voltage drop caused by changes in current flow from one circuit appears to the other circuit as noise on the common line. This noise represents cross coupling. Because the isolation lines are not intended to carry large amounts of current, it is not necessary that they be kelvin connected. However, on some embodiments, cross talk can be reduced further by kelvin connecting the isolation lines to I/O pads.
Though the isolation line is connected to ground, using a separate isolation line further reduces the cross coupling. FIG. 3 shows that all of the power lines for the interpolators in channel 1 are connected to I/O pad 314. All of the ground lines for the interpolators in channel 1 are connected to I/O pad 313. All of the isolation lines for interpolators in channel 1 are connected to I/O pad 312. Similar connections are made to other pads for each of the other channels on chip 300.
Turning to FIG. 4, details of the implementation of the ground bands are shown. Chip 300 is shown with a p-type substrate. Various regions are shown in which actual circuits are made according to standard design techniques. In FIG. 4, region 412A holds interpolator 116A. Region 412B holds interpolator 116B. Other regions (not shown), hold other circuits.
Guard rings 318, 316A and 316B are made by doping p+ type troughs around the appropriate circuit regions. The troughs encircle the circuit elements as shown in FIG. 3. These doped regions are then connected to I/O pad 312 using metallic traces 412 across the surface of chip 300.
FIG. 4 shows a further enhancement incorporated into chip 300. In region 410, the metallic traces for power, ground and isolation are routed to their pads. Region 410 is along the periphery of chip 300. Within the substrate of chip 300 below routing region 410 a further guard layer is employed. An n-type region 414 is doped into the substrate. An n+ region 416 is formed within region 414. The n+ region 416 is tied to ground pad 312. In this way, region 414 acts as a further barrier to noise that might induce cross talk. A primary purpose of region 414 is to isolate the metallic traces 412 from digital noise, such as might be generated by control circuits 310. Preferably, guard layer 410 will extend below substantially all of the routing region.
By employing guard regions, such as 316, 318 or 414, the timing errors in the interpolators caused by cross talk are greatly reduced. Reducing the cross talk allows multiple channels to be placed on a single chip. Increasing the number of channels on a single chip has great advantages. It reduces the overall size and cost of the test system dramatically. Much of the cost of a test system is in the circuitry needed to implement the channels. By putting more channels on one chip, the amount of circuitry is reduced. Fewer traces are required on the printed circuit boards. As a result, fewer or smaller printed circuit boards.
Having described one embodiment, numerous alternative embodiments or variations might be made. For example, several techniques are shown for reducing the cross talk of a tester with high channel density. Not all techniques need to be used simultaneously. The techniques might be used independently to obtain significant advantage.
Moreover, in some instances circuit elements are shown down to the transistor level. One of skill in the art will appreciate that other transistor layouts might be equivalent to the specifics disclosed.
Also, it was described that four tester channels are fabricated on each CMOS chip. Any number of channels might be implemented on a single chip, though preferably there will be more than two channels per chip. However, four or a higher number of channels is more preferred.
In addition, it is not necessary that the chips be CMOS. CMOS is the preferred implementation because it is widely available. However, other semiconductor technologies could be used. Some might be preferable for other applications. For example, GaAs circuitry might be preferred for higher speed test systems operating at system clock rates of 400 MHz or higher.
Another possible variation is the number of interpolators for each timing generator. Eight edges are described for each timing generator. Fewer edges might be used. For example, some automatic test equipment is made with as few as three timing edges per timing generator. More than eight timing edges are possible. More timing edges allows greater flexibility in programming the automatic test equipment.
As an example of another variation, FIG. 2B shows that a control signal is generated based on the voltage across capacitor 252, which acts as a filter capacitor. The improvement of FIG. 2B therefore makes the control signal less susceptible to noise on the power trace because the filtered output signal is taken to be the voltage across the capacitor 252. Traditionally, such a capacitor would be connected to ground and the filtered output signal would be taken to the voltage level at one terminal of the capacitor. Even if capacitor 252 had one terminal tied to ground instead of to V DD , advantages of the invention might be obtained with a circuit design that derived the control signal from the voltage across capacitor 252.
Also, it was described that guard rings are formed by doping p+ type impurities into the substrate. Other methods of forming guard rings might also be employed. The guard rings should preferably be conductive, but isolated from circuits on the chip by a reverse biased semiconductor junction. For example, if an n-type substrate were used, an n+ type impurity might be employed to form guard rings.
Therefore, the invention should be limited only by the spirit and scope of the appended claims.
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Automatic test equipment for semiconductor devices. The automatic test equipment contains numerous channels of electronic circuitry in which precisely timed test signals are generated. Significant advantages in both cost and size are achieved by incorporating multiple channels on one integrated circuit chip. To allow this level of integration without degrading timing accuracy, a series of design techniques are employed. These techniques include the use of guard rings and guard layers, placement of circuit elements in relation to the guard rings and guard layers, separate signal traces for power and ground for each channel, and circuit designs that allow the voltage across a filter capacitor to define a correction signal. Another feature of the disclosed embodiment is a fine delay element design that can be controlled for delay variations and incorporates calibration features. A further disclosed feature is circuitry that allows the tester to have a short refire recovery time.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an apparatus for controlling an internal combustion engine for use in an automobile, which is capable of preventing shock or surging occurring when the automobile runs in the low speed region.
2. Description of the Related Art
In an internal combustion engine for use in an automobile, which has a fuel injection control system, and in which the injection time, i.e., the amount of the fuel to be injected, is determined according to the load of the engine (intake of air or pressure in a suction pipe) and the number of revolutions of the engine, it is known that deceleration shock or surging (fluctuation of acceleration) occurs when a throttle valve is abruptly closed for the purpose of decelerating the automobile running at the low speed. This phenomenon results from the fact that the intake of air (or the pressure in the suction pipe) is sharply reduced due to the abrupt closing of the throttle valve and accordingly the injection time, which is originally calculated based on the intake of air, is also extremely reduced. As a result, the air/fuel ratio of mixture within a combustion chamber becomes large and over-lean condition is brought about, so that the necessary torque is not generated and a so called minus torque is caused. This minus torque resonates with a characteristic frequency of the automobile to produce a shock or surging. To prevent this, in the Japanese Patent Laid-open Publication No. 59-231144, for example, when a throttle valve is closed under a certain operational condition, the injection time is maintained at the value just existing before the closure of the throttle valve for a predetermined duration, and after that the injection time is slowly shortened.
Further, there is an internal combustion engine, in which, upon engine braking, fuel is cut if the number of revolutions of the engine is higher than a predetermined value. When the injection of fuel is restarted, the control of decreasing fuel is undertaken in order to prevent acceleration shock caused by the abrupt increase of fuel. In such a control, fuel which has adhered to an inner wall of a suction pipe is completely evaporated during the fuel cut and, after restart of injection, injected fuel is consumed to wet the inner wall of the suction pipe, so that the over-lean condition is temporarily caused in a combustion chamber. This also results in occurrence of shock or surging. To prevent the shock or surging of this kind, in the Japanese Patent Laid-open Publication No. 60-30446, for example, the injection time is increased by a predetermined rate, after it was once decreased upon restart of the injection.
In the prior art as described above, whether the shock or surging is actually occurring or not, the control for preventing the shock or surging, i.e., the enrichment of fuel, is always executed in the deceleration process of the automobile. Therefore, the prior art is in danger of deteriorating the performance of purification of exhaust gas. Besides, the prior art provides no effect against the surging which occurs during a constant speed running of the automobile, which is caused by the irregular combustion in the engine, the condition of a road surface and so on.
SUMMARY OF THE INVENTION
An object of the present invention is to provide an apparatus for controlling an internal combustion engine, which can prevent deceleration shock or surging from occurring during the low speed running of an automobile, without deteriorating the performance of purification of exhaust gas.
A feature of the present invention is that, in an internal combustion engine the output of which is controlled by varying the amount of fuel to be injected and the timing of ignition in accordance with parameters representative of the operational condition of the engine including at least the number of revolutions of the engine, the output of the engine is adjusted decreasingly when a changing rate of the number of revolutions of the engine is positive and its absolute value is larger than a predetermined value, and the output of the engine is adjusted increasingly when the changing rate of the number of revolutions of the engine is negative and its absolute value is larger than the predetermined value.
According to the present invention, the control for diminishing the deceleration shock or surging is executed only when it is actually detected and at the early time of its occurrence. Therefore, the deterioration of the purification of exhaust gas can be avoided, since the mixture supplied for the engine is not enriched more than necessary. In addition, the present invention functions effectively against the surging which occurs when an automobile is running at a constant speed.
Other objects, features and advantages of the present invention will become apparent upon reading the specification and inspection of the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 schematically shows the construction of an internal combustion engine to which the present invention is applied;
FIG. 2 is a block diagram roughly showing the construction of a control unit shown in FIG. 1;
FIGS. 3(a-b) explain the method of detecting the surging in the present invention;
FIGS. 4(a-c) explain the filtering operation used in an embodiment of the present invention;
FIGS. 5(a-b) show the relationship between the number of revolutions and the fuel injection period, when the compensation operation according to the embodiment of the present invention is conducted;
FIG. 6 is a flow chart showing the operation of a control apparatus according to the embodiment of the present invention, the operation according to the flow chart being executed in the control unit shown in FIG. 2;
FIGS. 7(a-b) show the relationship between the number of revolutions and the compensated ignition angle, when the compensation operation according to another embodiment of the present invention is conducted;
FIG. 8 shows an example of a manner of compensation according to the another embodiment;
FIG. 9 is a flow chart showing the operation of a control apparatus according to the another embodiment of the present invention, the operation of this flow chart being executed in the control unit shown in FIG. 2;
FIGS. 10(a-c) show the effect of the present invention at the time of the deceleration of an automobile, compared with the prior art; and
FIGS. 11(a-b) show the effect of the present invention during the constant speed running of an automobile, compared with the prior art.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring at first to FIG. 1, a brief explanation will be provided concerning the overall construction of an internal combustion engine, to which the present invention is applied. In the figure, reference numeral 10 denotes an engine, in which a combustion chamber 14 is defined by a cylinder 12 and a piston 16. To the combustion chamber 14 there are coupled one end of a suction pipe 18 and one end of an exhaust pipe 20. The other end of the suction pipe 18 is coupled through a collector portion 22 to a throttle body 24, in which a throttle valve is equipped. The throttle body 24 is coupled to an air cleaner 28 through a duct 26. Reference numeral 30 denotes an inlet of the air cleaner 28. The quantity of air sucked into the engine 10 is measured by an airflow meter 32 attached to a part of the duct 26. As the airflow meter 32, a hot wire type airflow meter can be employed, for example. A signal representative of the intake of air measured by the airflow meter 32 is sent to a control unit 34.
To a part of the suction pipe 18 there is attached a fuel injecting valve (injector) 36, which injects fuel supplied by a fuel pump 40 from a fuel tank 38 through a damper 42 and a filter 44, into the air sucked by the engine 10 for the opening duration thereof, which is varied in response to a signal from the control unit 34. By adjusting this opening duration (injection time), the air/fuel ratio of a mixture of air and fuel sucked into the combustion chamber 14 can be controlled. Further, there is provided a fuel pressure regulator 46, by which a part of the fuel is returned to the tank 38 when the pressure of fuel supplied to the injector 36 exceeds a predetermined value.
To the control unit 34 are given the following signals, in addition to the aforesaid signal of the quantity of air. One of them is, at first, a signal indicating the number of revolutions of the engine, which is sent from a crank angle sensor assembled within a distributor 48. Next is a signal from an idle switch attached to the throttle body 24, which represents that the throttle valve is closed. The control unit 34 also receives a signal from a cooling water temperature sensor 50, whereby the temperature of the engine 10 is taken into the control unit 10. Receiving these signals, the control unit 34 produces signals to the injector 36, the fuel pump 40 and an ignition coil 52. The signal to the ignition coil 52 controls the timing of generation of the high voltage which is supplied to the distributor 48, i.e., this signal adjusts the output of the engine 10 by varying the ignition timing.
FIG. 2 roughly shows the construction of the control unit 34 mentioned above. As is apparent from the drawing, the control unit 34 is formed by a known microprocessor comprising a processing unit (MPU), a read-only memory (ROM) and a random access memory (RAM) which are connected through busses. Further, to the MPU, an input/output (I/O) circuit is connected through a bus. Through this circuit, the MPU receives signals from a starter switch, an oxygen sensor and a battery voltage sensor, as well as the signals from the airflow meter, the crank angle sensor, the idle switch and the cooling water temperature sensor, which have been already described with reference to FIG. 1. Further, sensors or devices to be connected with the I/O circuit should not be construed in such a manner that they are limited to those described here or that they all are required for the implementation of the present invention. Receiving the signals from those sensors and devices, the MPU executes a predetermined processing and outputs the signals to the injectors, the ignition coil and the fuel pump through the I/O circuit. Although only one injector 36 is indicated in FIG. 1, it is to be understood that there are provided in this case one injector for every cylinder of a four cylinder engine.
Referring next to FIGS. 3 to 5, an explanation will be provided of the principle of the detection of the shock or surging and the diminishing method thereof according to an embodiment of the present invention.
If surging occurs, the number of revolutions of the engine 10 fluctuates. Further, as is apparent from FIGS. 3(A) and 3(B), when the fluctuation at the time of the loaded condition of the engine is compared with that under the non-loaded condition, the degree of the fluctuation is different to a great extent. Namely, a changing rate ΔN of the number of revolutions of the engine under the loaded condition is much larger than that of the engine under the non-loaded condition. Then, the fluctuation in the number of revolutions caused by the surging can be discriminated by providing an appropriate threshold ΔN R .
FIG. 4 is a chart showing the timing of the detection of the surging and the operation for diminishing it. Assuming that the number of revolutions fluctuates as shown in FIG. 4(a) due to the surging, the signal as shown in FIG. 4(b) appears for the duration of ΔN≧ΔN R . The filtering operation, which is described in detail later, starts simultaneously with the appearance of the signal of FIG. 4(b) and continues until the time T1 after the disappearance of the signal of FIG. 4(b).
Next, the filtering operation will be explained, referring to FIG. 5. The filtering operation is executed by a so called recursive digital filter represented by the following formula.
N=N.sub.y +G(N.sub.y -N.sub.y-1)
wherein N represents the number of revolutions modified by this filtering processing, which is utilized for the calculation for the fuel injection period (the width of the fuel injection pulse) of this time, N y denotes an actual number of revolutions taken for the filtering operation of this time, N y-1 represents the modified number of revolutions, which has been used for the calculation of the fuel injection period of the last time, and G denotes a constant.
Here let us assume that the number of revolutions of the engine fluctuates as shown by a solid line in FIG. 5(a). In the figure, the number of revolutions fluctuates stepwise, because it is shown in the form of the signal taken into the control unit 34, i.e., the solid line represents the change in sampling values, which is taken into the control unit 34 every sampling period. If the filtering processing as described above is applied to the signal of the number of revolutions as shown by the solid line in FIG. 5(a), the signal is changed as shown by a broken line in FIG. 5(a). The value indicated by the broken line is N obtained by the aforesaid formula. As apparent from the figure, when the actual number of revolutions changes decreasingly, the modified number of revolutions is made lower than the actual one. To the contrary, when the actual number of revolutions changes increasingly, the modified number of revolutions is made higher than the actual one. This is the meaning of the filtering operation indicated by the aforesaid formula. The filtering processing is executed y times (this appears as the number of steps seen in the figure) from the instances when the number of revolution changes from increase to decrease and vice versa. The number y of times of the filtering processing depends on the characteristic frequency of the automobile. Therefore, it must be finally fixed by experiment.
The period T p of the fuel injection is calculated on the basis of the thus modified number of revolutions. The way of obtaining the injection period T p is the same as the well known method, namely, it is basically obtained from the relation Q a/N , wherein Q a is the quantity of the suction air and N is the number of revolutions of the engine. The number of revolutions obtained by the modification of the filtering processing is used as N in the above mentioned relation.
The thus obtained injection period T p becomes as shown by a broken line in FIG. 5(b). A solid line in the figure indicates the injection period T p calculated on the basis of the number of revolutions shown by the solid line in FIG. 5(a), i.e., without the modification of the number of revolutions according to the filtering processing. For the convenience of the following explanation, the former injection period is called a compensated injection period and the later one an original injection period, hereinafter. As apparent from the figure, when the number of revolutions of the engine changes decreasingly, the injection period is compensated so as to be longer than the original one, whereby the output of the engine is increased and the fall of the number of revolutions is moderated. To the contrary, when the number of revolutions of the engine changes increasingly, the injection period is compensated so as to be shorter than the original one, whereby the output of the engine is decreased and the increase of the number of revolutions is also moderated. The hatched portions in FIG. 5(b) represent the compensated amount of the injection period.
The above described operation is executed by the MPU included in the control unit 34 in accordance with an operation flow shown in FIG. 6. Next, an explanation will be provided of the operation flow.
After the operation starts, the number N of revolutions is sampled at a predetermined sampling time and is read into the MPU at step 100. At step 102, a changing rate ΔN is calculated from N read at this sampling time and N' read at the last sampling time, and it is discriminated at step 102 whether ΔN≧ΔN R . If ΔN<ΔN R , the operation jumps to step 110, and N read at this sampling time is stored into a predetermined address of the storage. When ΔN≧ΔN R , it is discriminated at step 104 whether the sign of the changing rate ΔN changed. If not, the operation jumps to step 110. When the sign of the changing rate N has changed, the operation enters into the filtering process consisting of steps 105 to 108. In this process, the filtering operation is repeated Y times. After accomplishing the filtering process, the operation goes to step 110, at which the number N of revolutions read at step 100 is stored into the predetermined address of the storage.
As described above, the control for suppressing the shock or surging is executed only when it is actually detected (cf. step 102). In addition, as apparent from FIG. 5(b), the rich compensation always accompanies the lean compensation. As a whole, the mixture sucked into the combustion chamber is scarcely enriched. Therefore, the exhaust gas is not deteriorated.
In the following there will be explained another embodiment with reference to FIGS. 7 to 9. As is well known, the output of the internal combustion engine can be also adjusted by controlling the ignition timing. The ignition is usually conducted at the single read out from an ignition timing map stored in the storage in accordance with detected parameters indicative of the operational condition of the engine.
Then, assuming that, when the engine is operated with the ignition timing ADVM read out from the map, the fluctuation of the number of revolutions occurs as shown in FIG. 7(a). In this embodiment, when the number of revolutions of the engine changes decreasingly, the ignition timing is advanced with respect to ADVM, whereby the output of the engine is increased and the fall of the number of revolutions is moderated. When the number of revolutions of the engine changes increasingly, the ignition timing is delayed with respect to ADVM, whereby the output of the engine is decreased and the increase of the number of revolutions is moderated.
FIG. 8 shows an example of the compensation amount. In the figure, the abscissa indicates the order of the compensating operations counted from their commencement. Namely, the amount of the compensation is varied in accordance with the order of the compensating operation. Further, the ordinate indicates the absolute value ΔADV of the compensating amount. When the number of revolutions changes decreasingly, the values ΔADV corresponding to the respective orders of compensation are added to the present ignition angle ADVM read out from the ignition timing map. To the contrary, when the number of revolutions changes increasingly, the values ΔADV corresponding to the respective orders of compensation are subtracted from the present ignition angle ADVM. The relation as shown in FIG. 8 can be stored in the form of a table in the storage.
Further, the compensating amount shown in FIG. 8 is decreased every time of the compensation. However, the manner of selecting the compensating amounts for respective times is not limited thereto. For example, the compensating amount of the second time can be selected to be larger than that of the first time. It is desirable that the largest amount is made to correspond to the compensation of the time at which the changing rate of the number of revolutions indicates its maximal value. According to this, the largest compensation is added, when the number of revolutions is changing most sharply, so that the effect of diminishing the shock or surging is enhanced.
The above mentioned operation is executed by the MPU in the control unit 34 in accordance with an operation flow shown in FIG. 9. The operation flow of this figure is almost the same as that of FIG. 6. Step 106' is a main point, which is different from the flow of FIG. 6. It is easily understood that the operation of this step 106' is as described above.
As a modification of this embodiment, the following is considered. At step 106', the calculation for compensating an injection period T p is executed instead of the calculation for compensating the ignition timing ADV as shown in FIG. 9. Namely, a compensated injection period T p is obtained by varying the injection period T p ' calculated on the basis of an actual number of revolutions (not a modified number of revolutions) by a constant amount or a constant rate, which is appropriately selected.
FIGS. 10 and 11 show the effect of the present invention, compared with the prior art, in which FIG. 10 shows the effect at the time of the deceleration of an automobile and FIG. 11 shows the effect in the constant speed running. It will be understood that, according to the present invention, the surging is diminished in both cases of the deceleration and the constant speed running.
Further, it is to be understood that the embodiments mentioned above can be effectively used independently or in combination thereof. For example, upon detection of the occurrence of the shock or surging, if the compensation for both the fuel injection and the ignition timing is conducted, the effect of diminishing the shock or surging is further enhanced.
Although we have herein shown and described only some forms of apparatus embodying our invention, it is understood that further changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of our invention.
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In an apparatus for controlling an internal combustion engine having a fuel injection control system, the detected number of revolutions is so modified that it becomes higher than an actual number of revolutions when a changing rate of the number of revolutions is larger than a predetermined value and the actual number of revolutions tends upward, and lower than the actual one when the changing rate is larger than the predetermined value and the actual number of revolutions tends downward. The quantity of fuel to be injected is calculated on the basis of the thus modified number of revolutions. According to the present invention, the deceleration shock or surging occurring during the low speed running of an automobile can be effectively diminished without any deterioration of the exhaust gas.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to cooking apparatus, and, more particularly, to cooking apparatus for use within a fireplace.
2. Background Information
The patent literature includes a number of examples of apparatus providing a surface for cooking over a fire within a fireplace, with a portion of the apparatus being fastened to one or more surfaces of the fireplaces, and with the surface to be used for cooking being adjustable but not readily removable from the portion of the apparatus fastened in place within the fireplace. For example, U.S. Pat. No. 3,834,370 describes a grill for use in a fireplace or outdoors comprises a 1 rack and pinion elevating assembly. A shaft which operates the pinion may be pushed to lock the elevating assembly and pulled to unlock the elevating assembly so that the grill may be raised or lowered. The grill may be tilted and latched in any one of several tilted positions.
U.S. Pat. No. 4,766,879 describes another example of such apparatus, in which a fireplace cooking grill is supported for vertical and horizontal adjustment in a fireplace opening with the grill being supported from a vertically disposed support post having a rack Sear along one edge thereof with the grill including a slide on the post having a manually rotatable gear mounted in a gear housing in engagement with the rack gear for vertically adjusting the grill. The rotatable gear is provided with a detachable handle, which can be removed when desired, and the gear housing includes a bracket having a horizontally disposed support member slidably supporting a grill frame and a removable grill therein which enables the grill to be vertically adjustable in relation to the fireplace and horizontally adjustable inwardly and outwardly of the fireplace to enable optimum positioning of the grill in relationship to a fire, coals, or other heat source in the fireplace.
Yet another example of such apparatus is described in U.S. Pat. No. 4,911,146, in the form of a fireplace cooking device which provides for translation a grill or other cooking device in three orthogonal directions. The device has a wall assembly, which attaches to the sidewall of the fireplace and maintains a mechanism to raise or lower a grill or other cooking device. Attached to the wall assembly are a series of elements which are pivotably mounted to provide planar translation of a grill or other cooking device.
What is needed is apparatus providing a cooking surface without a necessity for fastening a portion of the apparatus in place within the fireplace. Furthermore, what is needed is a method for readily removing the cooking surface for cleaning or to provide for other uses of the fireplace.
U.S. Pat. No. 4,086,905 describes a combination fire grate and fireplace cooking grill in which a modular design facilitates the use of various sizes of fuels, such as charcoal or wood. A lightweight handle with a coupling configuration is provided for repositioning the cooking grill with respect to the fire, and/or for removing the cooking grill and food from the fire. This coupling means is designed to quickly and positively engage the cooking grill when inserted from a direction approximately perpendicular to the cooking surface. As the handle is then displaced arcuately towards the plane of the cooking surface, a novel hook-shaped tip portion and basal portion of the coupling means of the handle matably engage appropriately formed surfaces on the cooking grill because the secure inner connection of the handle and cooking grill. Further arcuate displacement of the handle then causes a tracking portion formed on the cooking grill to disengage from stops to thereby allow the cooking grill to be moved freely to any of a variety of cooking positions, or to be removed entirely for serving. What is needed is a cooking grill having an elongated handle to allow installation and removal of the cooking grill without a need to grip a surface near a fire being held within the grate. Additionally, what is needed is a simple structure, such as slots, each open at one end, for removably engaging the cooking grill. Furthermore, what is needed is a frame mounting the cooking grill, with the frame being separate from the grate, so that the cooking apparatus can be used with an existing grate.
A conventional Hibachi unit typically includes a pair of slotted brackets that are used to hold removable cooking grills at various levels above a charcoal fire held within the Hibachi unit. Examples of such units are described in U.S. Pat. Nos. 4,256,080 and 4,413,609. What is needed is an apparatus for fireplace cooking employing slotted brackets to hold one or more removable cooking grills at various levels above a fire in the fireplace.
U.S. Pat. Nos. 4,083,354 and 4,553,525 describe portable grill apparatus including a food grill adjustably clamped to an upstanding elongated member supported by a foot assembly. The device can be used to hold the food grill over a fire in an outdoor campsite or in a fireplace. What is needed is a frame for removably holding one or more cooking grills behind a fire within a fireplace.
SUMMARY OF THE INVENTION
In accordance with a first aspect of the invention, apparatus is provided for cooking food within a fireplace having a space for building a fire. The apparatus includes a food grill and a frame. The food grill includes a food support surface and an elongated handle extending from a proximal end of the food support surface. The frame includes a coupling portion, a support portion, and a base portion. The coupling portion removably accepts a distal end of the food grill to hold the food grill to extend horizontally outward from the coupling portion, above the space for building a fire. The support portion extends downward from the coupling portion to be disposed behind the space for building a fire. The base portion extends outward from a lower end of the support portion to be disposed along a floor of the fireplace below the space for building a fire.
It is understood that the space for building a fire is disposed upward from the floor of the fireplace, for example, by a conventional grate holding wood or other fuel, so that air can be brought upward through the grate to support combustion. The upward and downward directions are accorded their ordinary meanings with the cooking apparatus sitting in the fireplace under conditions of normal use. The outward direction is understood to be the direction extending outward from the fireplace opening into a room. A food grill in place within the apparatus is understood to have a proximal end facing in this outward direction and a distal end held by the frame.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 is a left elevation of cooking apparatus built in accordance with the invention, shown within a fireplace;
FIG. 2 is a front elevation of the cooking apparatus of FIG. 1 , also shown within the fireplace;
FIG. 3 is a plan view of the cooking apparatus of FIG. 1 ; and
FIG. 4 is a plan view of a frame within the cooking apparatus of FIG. 1 ;
DETAILED DESCRIPTION OF THE INVENTION
FIGS. 1 and 2 show fireplace cooking apparatus 10 built in accordance with a first embodiment of the invention, as used within a fireplace 11 , with FIG. 1 being a front view of the cooking apparatus 10 , while FIG. 2 is a front view thereof. The cooking apparatus 10 includes a frame 12 and a pair of removably attached food grills 14 . The food grills 14 hold food objects 16 above a fire 18 built using pieces of wood 20 held within a grate 22 , which may be a conventional device. The grate 22 holds the wood 20 spaced above a floor 24 of the fireplace 11 to allow air to move upward between spaced-apart grate members 26 and to provide a space for the placement of fire starting materials, such as rolled paper. These grate members 26 are held in place by a descending grate support structure 28 .
FIG. 3 is a plan view of the cooking apparatus 10 . Each of the food grills 14 includes a generally rectangular grilling portion 30 including ribs 32 extending among rectangular spaces 34 through which the food objects 16 (shown in FIGS. 2 and 3 ) are heated by a combination of radiation and convection from the fire below, and through which juices are allowed to drip. The food objects 16 are additionally heated by conduction from the ribs 32 . Each of the food grills 14 also includes an elongated handle 36 extending outward to a round grip 38 through a distance sufficient to allow the grill 14 to be moved without reaching near or over the fire 18 .
FIG. 4 is a plan view of the frame 12 . Referring to FIGS. 1 , 2 and 4 , the frame 12 includes a coupling portion 40 a support portion 41 , and a base portion 42 . The grill attachment portion 40 includes four upstanding slotted grill attachment brackets 44 , each of which includes a slotted portion having a number of grill attachment slots 46 , extending between flat sides of the slotted portion from a narrow edge of the slotted portion, and arranged to accept the distal ends 48 of the food grills 14 . Each of the food grills 14 can be moved vertically from one pair of slots 46 in adjacent grill attachment brackets 44 to another to vary the distance between the fire 18 and the grill 14 . While each of the slots 46 has an open end 50 that is preferably enlarged to permit easy entry of the distal end 48 , the slots 46 are preferably configured to hold the grills 14 to extend nearly horizontally. In the example of the figures, each of the grill attachment brackets 44 additionally includes a twisted portion 52 , extending between the slotted portion of the grill attachment bracket 44 and a lower portion of the grill attachment bracket 44 providing for attachment to an upper crossbar 54 , which holds the attachment brackets 44 so that each of the grills 14 is held in a pair of adjacent brackets 44 , with a flat side of the lower portion of the grill attachment bracket 44 being attached to the upper crossbar 54 .
The support portion 41 of the frame 12 , which extends downward from the coupling portion 40 , includes upper legs of a pair of L-shaped stand brackets 56 extending vertically between the upper crossbar 54 and the base portion 42 , being attached to the upper crossbar 54 , with the upper crossbar 54 holding the grill attachment brackets 44 horizontally spaced apart from one another and from the upper legs of the stand brackets 56 . The base portion 42 includes lower legs of the L-shaped stand brackets 56 . The base portion 42 additionally includes a front crossbar 56 and a rear crossbar 58 extending between the L-shaped stand brackets 56 . The base portion 40 includes a pair of small L-shaped brackets 62 extending rearward from the L-shaped stand brackets 62 to provide additional stability on the fireplace floor 24 .
The apparatus 10 is particularly configured to provide for supporting the food items 16 above the fire 18 , built within a central portion of the fireplace 11 . To this end, the support section 41 is configured to be disposed behind the fire 18 while the base portion 42 is configured to be disposed below the fire 18 , extending along the floor 24 of the fireplace 11 .
Using the apparatus of the present invention provides a number of advantages over the use of background art cooking methods. For example, in comparison to the use of conventional barbecue or Hibachi apparatus, or of the apparatus described in U.S. Pat. Nos. 4,256,080 and 4,413,609, the present invention provides an easy way to cook within a fireplace, so that food can be cooked over an open fire during inclement weather without leaving a building.
In comparison with the apparatus described in U.S. Pat. No. 4,086,905, the present invention provides a section for holding the food grills that is behind instead of in front of the fire, so that the fire can be more effectively used for other purposes when it is not being used for cooking. Also, the elongated handle of the present invention allows the food grills to be installed on and removed from the frame without moving one's hand close to the fire. Furthermore, the present invention provides a more straightforward method of removing, installing, and changing the position of the food grills. Additionally, the present apparatus provides cooking apparatus that can be used with a pre-existing grate.
In comparison with the apparatus described in U.S. Pat. Nos. 3,834,370, 4,911,146, and 4,766,879, the present apparatus provides the advantages of food grills that are readily removable for serving, cleaning, and for using the fireplace for purposes other than cooking, including the processes necessary to build and maintain a fire. Additionally, the present invention provides a frame that is disposed behind and under a grate within the fireplace, instead of beside the grate, as in the background are. Furthermore, the present invention is easily set in place within the fireplace, without a need to fasten or clamp the frame to structures of the fireplace.
In comparison with the apparatus described in U.S. Pat. Nos. 4,083,354 and 4,553,525, the present invention provides the advantage of a frame that is disposed behind and under a grate instead of a frame that has to be placed on the hearth in front of the fireplace, together with the advantage of food grills that are easily removable from the frame.
While apparatus including a pair of food grills has been shown and described, it is understood that similar apparatus could be built in accordance with the invention to provide for only a single food grill or for many more food grills.
While the frame 12 has been shown as being formed by welding metal strips together, it is understood that such a frame may alternately be made by bolting strips together or by casting an integral structure.
It is further understood that the right elevation of the apparatus is a mirror image of the left elevation, shown in FIG. 1 , and that the rear and bottom sides of the apparatus (not shown) do not include decorative features.
While the invention has been shown 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 many changes may be made without departing from the spirit and scope of the invention, as described in the appended claims.
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A frame holding removable food grills is provided for cooking food within a fireplace. The frame extends behind and below a convention grate holding a fire within the fireplace. The grills are removably held in slots within the frame, with a number of slots being provided for placing the grills at various distances above the fire.
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RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent application Ser. No. 11/098,941, filed Apr. 5, 2005, which, in turn, is a continuation of U.S. patent application Ser. No. 09/818,986, filed Mar. 27, 2001, which issued as U.S. Pat. No. 6,963,552, which claims the benefit of U.S. Provisional Application Ser. No. 60/192,186, filed on Mar. 27, 2000, all of which are incorporated herein by reference.
BACKGROUND
[0002] The wireless telecommunication industry continues to experience significant growth and consolidation. In the United States, market penetration is near 32% with approximately 86 million users nationwide. In 1999 the total number of subscribers increased 25% over the previous year, with the average Minutes of Use (MOU) also increasing by about 20% per user. If one considers growth in the digital market, in as short as three years, the digital subscriber base has grown to 49 million users, or approximately equal to the installed number of users of analog legacy systems. Even more interesting is an observation by Verizon Mobile that 70% of their busy hour traffic (an important system design parameter) is digital traffic, although only approximately 40% of the total number of their subscribers are digital users. The Verizon Mobile observation indicates the digital subscriber will drive the network design through its increasing usage, whereas the analog user is truly a passive “glovebox” subscriber.
[0003] Similar growth has been witnessed in other countries, especially in Northern and Western Europe, where market penetration is even higher, approaching 80% in some areas, and digital service is almost exclusively used.
[0004] With the availability of Personal Communications Service (PCS) frequencies in the United States, and additional continuing auctions of spectrum outside of the traditional 800-900 MegaHertz (MHz) radio band, the past few years have also seen increased competition among service providers. For example, it has also been estimated that 88% of the US population has three or more different wireless service providers from which to choose, 69% have five or more, and about 4% have as many as seven service providers in their local area.
[0005] In 1999 total wireless industry revenue increased to $43B, representing an approximate 21% gain over 1998. However, a larger revenue increase would have been expected given the increased subscriber count and usage statistics. It is clear that industry consolidation, the rush to build out a nationwide footprint by multiple competing service providers, and subsequent need to offer competitive pricing plans has had the effect of actually diminishing the dollar-per-minute price that customers are willing to pay for service.
[0006] These market realities have placed continuing pressure on system designers to provide system infrastructure at minimum cost. Radio tower construction companies continue to employ several business strategies to serve their target market. One approach, their historical business strategy, is build-to-suit (i.e., at the specific request and location as specified by a wireless operator). But some have now taken speculation approach, where they build a tower and then work with local government authorities to force new service providers to use the already existing towers. This speculation build approach, spawned by the zoning by-law backlash, is actually encouraged by communities to mitigate the “unsightly ugliness” of cellular phone towers. This is seemingly the best alternative, since Federal laws no longer permit local zoning authorities to completely ban the deployment of wireless infrastructure in a community. Often the shared tower facility is zoned far removed from residential areas, in more commercialized areas of town, along heavily traveled roads, or in more sparsely populated rural sections. But providing such out of the way locations for towers often does not fully address each and every wireless operator's capacity or coverage need.
[0007] Each of the individual wireless operators compete for the household wireline replacement, and as their dollar-per-MOU is driven down due to competition in the “traditional” wireless space, the “at home” use is one of the last untapped markets.
[0008] As the industry continues to consolidate, the wireless operator will look for new ways to offer enhanced services (coverage or products) to maintain and capture new revenue.
[0009] Considering the trends that have appeared over recent years, when given the opportunity to displace the household wireline phone with reliable wireless service, a wireless service operator may see their average MOUs increase by a factor of 2 to 4, thereby directly increasing their revenue potential 200 to 400%. In order to achieve this, the wireless operator desires to gain access throughout a community as easily as possible, in both areas where wireless facilities are an allowed use and in where they are not, and blanket the community with strong signal presence.
SUMMARY
[0010] Certain solutions are emerging that provide an alternative to the tower build out approach. In particular, wireless signal distribution systems employ a distribution media such as a cable television infrastructure or optical fiber data network to distribute Radio Frequency (RF) signals. This allows the capacity of a single base station to be distributed over an area which is the equivalent of multiple traditional cellular sites without degradation in coverage or call quality.
[0011] However, even these systems have a shortcoming in that they are typically built out for one selected over the air protocol and are controlled by a single service provider. Thus, even with such systems as they are presently known, it becomes necessary to build out and overlay multiple base stations and multiple signal distribution networks for multiple service providers.
[0012] The present invention is an open access signal distribution system in which a variety of wireless voice, data and other services and applications are supported. The open access systems makes use of a distributed Radio Frequency (RF) distribution network and associated network entities that enable the system operator to employ a wireless infrastructure network that may be easily shared among multiple wireless service providers in a given community. The open access system provides the ability for such operators and service providers to share the infrastructure regardless of the specific RF air interface or other signal formatting and/or managing messaging formats that such operators choose to deploy.
[0013] In one configuration, the present invention consists of a system in which a base station interface located at a central hub location converts radio frequency signals associated with multiple base stations, of the same or even different wireless service providers, to and from a transport signaling format. A shared transport medium, such as a fiber optic data network or the like is then used for transporting the converted signals from the hub location to a number of remote access node locations.
[0014] The access node locations each have Radio Access Node equipment located therein. The Radio Access Nodes (RANs) are each associated with a particular coverage area. The RANs have within them a number of slice modules, with each slice module containing equipment that converts the radio signals required for a particular service provider to and from the transport signaling format.
[0015] In a preferred embodiment, the transport medium may be an optical fiber telecommunications network such as provided through the SONET type digital frame formatting. In such a configuration, the SONET data formatting is arranged so that certain data frames are associated with the slices in a given Radio Access Node on a time slotted basis. In such a configuration, signal down converter modules convert the radio frequency signals associated with each base station to an Intermediate Frequency (IF) signal. Associated analog to digital (A/D) modules also located at the hub then convert the Intermediate Frequency signals to digital signals suitable for handling by a transport formatter that formats the converted digital signals to the proper framing format for the SONET digital transport.
[0016] Other transport media may be used such as Internet Protocol (IP) over Digital Wavelength Division Multiplexing (DWDM).
[0017] In one other aspect the invention concerns the aggregation of different Radio Frequency (RF) signaling formats onto a common transport mechanism. In this embodiment, a first and second base station operate according to respectively, first and second different wireless system air interfaces. A transport medium interface converts the radio frequency signals transmitted by the first and second base stations to a common transport medium. The first and second base station may optionally also be operated under the control of two different service providers. In this arrangement, a plurality of remotely located Radio Access Nodes (RANs) each provide radio signal coverage to a predetermined portion of a total system coverage area. Each Radio Access Node is coupled to receive signals from the common transport medium. Each Radio Access Node also contains a first and second slice module associated with the respective one of the first and/or second base station. Each slice module contains a suite of radio transmitter, amplifier and antenna equipment as required by its associated air interface.
[0018] In another aspect the present invention concerns equalizing power levels of Radio Frequency signals radiated by the Radio Access Nodes at levels appropriate for respectively different air interfaces. In particular, in such a system a first and second base station are located at a central location and operate according to respectively different wireless system air interfaces. A transport medium interface converts the Radio Frequency signals transmitted by the first and second base stations to a common transport medium signaling format. At a plurality of remote locations Radio Access Nodes (RANs) are located. Each Radio Access Node is coupled to receive signals from the common transport medium. Each Radio Access Node contains at least a first and second slice module that is associated with and responsible for converting signals associated with the first and second base stations.
[0019] In this instance, the invention includes means for equalizing the receive sensitivities of the Radio Access Nodes at levels for the appropriate for the respectively different air interfaces, such as by managing the number of RANs in simulcast depending upon the particular air interface.
[0020] This configuration permits for example, the deployment for the set of shared RANs at common RAN remote locations without having to deploy multiple RAN locations for different air interfaces even when such air interfaces have different receive sensitivities and coverage distances. Thus the Radio Access Nodes for two or more different air interfaces may be co-located throughout the coverage system area reducing the overall system build out requirements.
[0021] In yet another aspect, the present invention is a method for providing access to radio equipment distributed throughout a coverage area to multiple wireless communication service providers. This method involves the steps of accepting requests for radio signal distribution service from the service providers, the request specifying a desired air interface and an indication of which portions of a coverage area the particular air interface is to be supported. The service provider then installs common base station equipment operating with the air interface specified by the service provider at a central location with the base station equipment being co-located with base station equipment specified by other wireless service providers. The commonly located base station equipment is then coupled to receive traffic signals from a signaling network used by the wireless communication service provider, the signaling network carrying such transport formatted Radio Frequency signals over a common transport medium. A data processor then controls the connection of transport signal to specific Radio Access Nodes as specified by the wireless system operator.
DRAWINGS
[0022] The foregoing and other objects, features and advantages of the invention will be apparent from the following more particular description of preferred embodiments of the invention, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention.
[0023] FIG. 1 is a block diagram of an open access system according to the invention.
[0024] FIG. 2 illustrates one possible deployment for the open access system.
[0025] FIG. 3 is a more detailed diagram of a hub signal path for the open access system.
[0026] FIG. 4 is a more detailed diagram of a Radio Access Node signal path.
[0027] FIG. 5 shows one example of a calculation to determine how simulcast operation can be coordinated to equalize a reverse link budget and provide balancing with a forward link budget.
[0028] FIG. 6 is a more detailed view of a cross connect providing for the ability to connect multiple base stations for different wireless operators to a network of Radio Access Nodes.
[0029] FIG. 7 is a diagram illustrating how RAN slices may be allocated to different tenants and sectors in simulcast.
[0030] FIG. 8 is a more detailed view of one possible configuration for the hubs and RANS over which both the transport traffic signals and control signaling may be carried.
[0031] FIG. 9 is a detailed view of one possible antenna configuration.
DETAILED DESCRIPTION
[0032] A description of preferred embodiments of the invention follows.
[0033] While this invention has been particularly shown and described with references to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the invention encompassed by the appended claims. Turning attention now to the drawings more particularly, FIG. 1 is a diagram of an open access system 10 . The open access system 10 is an open access network supporting a multitude of wireless voice, data, video services and applications. Wireless Service Providers (WSP) and Wireless Internet Service (WISP) Providers, commonly known as tenants, may use open access system 10 to either enhance or replace existing networks, wired or wireless, or to develop new networks.
[0034] Open access system 10 is a multi-frequency, multi-protocol Radio Frequency (RF) access network, providing cellular, Personal Communication Services (PCS), and wireless data coverage via a distributed RF access system. Open access system 10 is comprised of base stations 20 , located at hub sites 30 . The base stations 20 are connected via high speed datalinks 40 to distributed RF access nodes (RANs) 50 . The system 10 is, in effect, a signal distribution network and associated management entities that enable a network operator to deploy a wireless infrastructure network that may easily be shared among multiple wireless system operators in a given community. The open access network may be shared regardless of the specific RF air interface formatting and management messaging formats that each wireless operator chooses to deploy.
[0035] FIG. 2 depicts one possible deployment scenario for the open access system 10 . As shown, the system consists of a multiple Radio Frequency (RF) Access Node 50 (RAN) units that may be located at relatively lower height locations such as utility poles. The open access network 10 distributes RF signals to and from the RANs, using a shared transport media 40 such as an optical fiber using high speed transport signaling. The physical deployment of the open access system is thus quite different from the higher radio towers required in a conventional system.
[0036] Returning attention to FIG. 1 , the hub 35 provides the hardware and software interfaces between the high speed data link 40 and the individual wireless carrier base stations 20 . The base stations 20 are considered to be original equipment manufacturer (OEM) type equipment to be provided and/or specified by the tenant 15 and are not provided as part of the open access system 10 itself Hub 35 co-locates with the base stations 20 at a designated hub site 30 . In a maximum configuration, a 3-sector base station 20 connects to 24 RAN Units 50 , via an open access Hub 35 . Hub 35 can be expanded to connect multiple base stations 20 (one or multiple wireless carriers) and their associated RAN Units 50 .
[0037] RAN units 50 are distributed throughout a given community in accordance with the network operator's RF plan. RAN Units 50 , along with associated antennas 56 , are typically/installed on utility poles 58 , and connect to Hub Unit 35 via a fiber optic cable 40 .
[0038] Network Management System 60 provides remote monitoring and control of the open access network by the network operator via the open access system 10 . Network Management System 60 also allows for the network operator to pass selected control or status information concerning the open access network 10 to or from the individual wireless carriers or tenants. By “tenant” it is meant to refer to the wireless carrier, Wireless Service Provider (WSP), or other business entity that desires to provide wireless service to end customers.
[0039] The open access system 10 supports essentially any wireless protocol to be an open Access platform. In one configuration, open access system 10 supports the multiple 800/1900 MHz wireless service providers, and wireless data providers who require last mile access to their targeted customers, all at the same time. In another configuration, open access system 10 supports the lower frequency 400 and 700 MHz bands and the WCS/ISM/MMDS, U-NII wireless data bands.
[0040] In a preferred configuration, the open access network consists of radio access nodes (RAN) 50 distributed to achieve the desired RF signal presence and a hub 35 and high speed data link 40 , which interconnects the base station RF signals with the RANs 50 .
[0041] The distributed architecture is comprised of multi-protocol, frequency-independent radio access nodes 50 . In the preferred embodiment at the present time, each RAN 50 supports from 1 to 8 operators, commonly referred to as tenants 15 , of various protocols and frequencies. It should be understood that other configurations could support a smaller or greater number of tenants per RAN 50 . Within each RAN 50 , the wireless service provider “tenants” have typically leased space for the service provider to install corresponding individual radio elements in a RAN slice 52 . RANs 50 connect to a centralized base station locale 30 where the tenants 15 connect to through an open access HUB 35 to the specific tenant's base station electronics. Each HUB 35 can scale to support one to three sectors of a base stations 20 . It should be understood that base stations with a greater number of sectors 20 may also be supported.
[0042] RANs 50 are interconnected via fiber links 40 to centrally located HUB sites 30 and associated base stations 20 . RANs 50 wide area distribution is logically a “horizontal tower” with access provided to a single “tenant” or shared amongst multiple tenants (wireless service providers). The generic architecture supports scaling from a single operator to supporting up to multiple operators across the multiple frequency bands per shelf. Multiple shelves may be stacked to serve additional tenants, as needed.
[0043] HUB 35 and RAN 50 network elements incorporate a System Network Management Protocol (SNMP) communication scheme to facilitate integration with the Host operator's network management system 60 . This allows easy and complete communication across the open access system 10 with a high level of control and visibility.
[0044] Referring now to FIG. 3 , an RF signal is transmitted from a BTS 20 to open access hub 35 . The RF signal is of any bandwidth up to typically 15 MHz (future bandwidths may be greater) and follows the hub signal path as shown in FIG. 3 . The signal is down converted to a 50 MHz (+/−7.5 MHz) Intermediate Frequency (IF) signal by the down converter (D/C) 100 . The IF signal is then converted to a 14 byte stream, at least at 42.953 Msps, by analog-to-digital (A/D) channelizer 102 . Two control bits are added to the stream at a field programmable gate array (FPGA) within the A/D channelizer 102 . The 16 byte stream, still at 42.953 Msps, is then serialized using 8B/10B encoding producing a 859 Mbps bit stream or an STS-12 type transport signal. The STS-12 signal is then distributed along a number of paths equal to the number of RANs in simulcast for each BTS sector. The STS-12 signal is preferably transmitted to the designated RAN Units 50 by interconnect 106 cross-connecting the STS-12 signal to a 4:1 multiplexer 108 that converts the STS-12 signal to an OC-48 signal. In a preferred embodiment, as shown in FIG. 1 , a base station 20 located at any hub site 30 can transmit its associated signal to any RAN Unit 50 using a digital cross-connect 37 connected between Hubs 35 . In one example, lower rate signals (STS-3, 4, etc.) may be combined into higher rate shared transport signals (e.g. OC-192).
[0045] Referring to FIG. 4 , the OC-48 signal enters a multiplexer 108 where the signal is converted from an OC-48 signal back to a STS-12 signal. The STS-12 signal is then digital-to-analog (D/A) converted to a 50 MHz (+/−7.5 MHz) signal by the D/A Channelizer 110 . The 50 MHz (+/−7.5 MHz) signal is up converted 112 (U/C) to the required RF signal between. The RF signal is then power amplified (PA) 114 at its associated RF frequency and transmitted through diplexer 116 that couples transmit and receive signals to the same antenna. The RF signal is then radiated by the antenna.
[0046] Referring to FIG. 4 , an RF signal is received by an antenna or antenna array and the signal is then down converted (D/C) 100 to a 50 MHz (+/−7.5 MHz) signal. The RF signal is then converted to a 14 bit stream, at least at 42.953 Msps, in the (A/D) channelizer 102 . Two control bits are added to the bit stream at a digital filter implemented in a Field Programmable Gate Array (FPGA) within the A/D channelizer 102 . The 16 byte stream, at least at 42.953 Msps, is serialized using 8B/10B encoding producing a 859 Mbps bit stream or STS-12 signal. The STS-12 signal is then combined with the other tenant signals by a 4:1 multiplexer 108 that converts the STS-12 signal to an OC-48 signal. This signal is then transmitted to the designated open access hub 35 .
[0047] Referring to FIG. 3 , the OC-48 signal is received at the open access hub 35 at the multiplexer 108 that converts the OC-48 signal to a STS-12 signal. The STS-12 signal is then cross-connected through interconnect 106 to a designated BTS 20 . The STS-12 signal is summed up to 8, 1 with signals from other RANs in the same simulcast and is then D/A converted 110 to a 50 MHz (+/−7.5 MHz) IF signal. It should be understood that in other configurations, more than 8 signals could be summed together. The 50 MHz signal IF signal is the up converted (U/C) 112 to the desired radio carrier and forwarded to the BTS 20 . Providing for two receive paths in the system 10 allows for receive diversity.
[0048] The location of the RANs will be selected to typically support radio link reliability of at least 90% area, 75% at cell edge, as a minimum, for low antenna centerline heights in a microcellular architecture. The radio link budgets, associated with each proposed tenant 70 , will be a function of the selected air protocol and the RAN 50 spacing design will need to balance these parameters, to guarantee a level of coverage reliability.
[0049] Because of differences in air interface performance and mobile unit transmit powers/receive sensitivities the open access system 10 requires additional design considerations. For example, an optimal RAN location grid spacing for an IS-136 TDMA protocol is not the same as for an IS-95 CDMA protocol.
[0050] To minimize the number of RANs 50 , open access multi-protocol wireless infrastructure requires that all the participating wireless protocols share common geographic transmit/receive locations. These locations are referred to as shared RANs 50 , and the distance at which they can be located from any serviceable mobile unit sets the nodes' maximum separation. However, this distance limit is different for each wireless protocol due to performance differences in their respective air interface power or link budgets. A simple, but non-optimum, approach is to determine the RAN 50 locations on the wireless protocol requiring the closest spacing (i.e. smallest RF link budget). The base stations 20 located at the central hub sites 30 are then optically connected to the co-located RAN sites 50 giving each protocol the same coverage footprint per base station sector. This approach is highly non-optimum for those protocols having larger link budgets and will yield heavily overlapped coverage areas. Similarly, basing RAN spacing on the larger link budget will yield coverage gaps for the weaker link protocols.
[0051] According to the present invention, differences between the wireless protocols' link budgets are equalized through simulcasting of multiple RANs sites 50 . Simulcasting allows a wireless infrastructure provider to reduce the link budget of the RAN 50 for higher power protocols to match those of the others, while increasing the net coverage range of the associated base station sectors 20 . A reduction in a RANs 50 link budget (and therefore coverage range) is offset by the increase in the number of RAN's 50 that can be simultaneously served by the associated base station sectors 20 . This maintains the base station 20 coverage area for the protocols with a large link budget while maintaining the closer RAN 50 spacing required for those protocols with a small link budget. At the same time, the reverse link can be brought into balance with the forward link for a wide variety of forward RF carrier power levels.
[0052] FIG. 5 shows a simplified link budget for three example collocated protocols: IS-136 (TDMA), GSM 1900 and CDMA. It should be understood that the same principles apply to other wireless air interfaces such as: PEN, GSM, 3G (GPRS/EDGE), CDMA 2000, W-CDMA, etc. The protocol with the lowest intrinsic reverse link budget (IS-136) is balanced with the CDMA protocol through the use of a larger number of RANs in the simulcast group for CDMA. All of the protocols' simulcast is also collectively scaled to balance with the forward link. For a higher-power deployment than is shown in FIG. 5 (similar to that of a large tower) the least robust air interface typically uses a simulcast of one and all other air interfaces scale up from there. Since the illustrated scenario is for is a lower power microcellular build-out, all protocols use a non-unity simulcast. The forward transmit powers for each RF carrier are properly scaled to equalize the forward link budgets of the various protocols. Call capacity per geographic area is finally established by selecting the number of RF carriers based upon the final simulcast ratio.
[0053] The determination of parameters may proceed as follows.
[0054] Forward and reverse RF link budgets are first established for each of the wireless protocols of interest. At this point, simulcast is not entered as a factor into the analysis.
[0055] The wireless protocol with the smallest link budget is then identified and its coverage area and capacity are optimized.
[0056] The system build-out, lower power (and smaller size) power amplifiers are used to minimize cost and size of the installation. Simulcast of multiple RANs 50 is used to bring the forward and reverse paths in balance for the above identified wireless protocol. This establishes the allowable RF path loss and therefore the physical spacing for the shared RANs 50 .
[0057] For each of the other collocated protocols, the number RANs 50 in simulcast are selected to match the baseline link budget established above. Each protocol will have a different simulcast number. The sensitivity at each RAN 50 will change as
[0058] 10 log.sub.10 (the number of RANs 50 in simulcast).
[0059] The forward transmit power levels are then adjusted to bring the forward and reverse paths into agreement.
[0060] The number of simultaneous RF carriers is selected for each protocol based upon the call capacity required in the geographic coverage area. Changing the number of carriers does not affect the link balance or the number of RANs 50 in simulcast.
[0061] Referring to FIG. 6 , this type of infrastructure build-out requires a distributed RF system capable of cross-connecting multiple base stations 20 from different tenants or Wireless Service Providers (WSPs) to a network of RANs 50 using distribution ratios that differ for each wireless protocol. A network that does not support this aspect of the invention would simply connect the base station sectors for all the WSPs to the same complement of RANs 50 . Sector 1 /WSP 1 through sector 1 /WSP n would all connect to the same RANs 50 . Similarly, sector 2 /WSP 1 through sector 2 /WSP n connect to a different but common group of RANs 50 .
[0062] Referring to FIGS. 6 and 7 , the system described by this invention selects a different simulcast scheme for each individual sector of each wireless operator and the total collection of RANs 50 distributed through a geographic coverage area. For example: Sector 1 /WSP 1 does not necessarily connect to the same complement of RANs 50 as sector 1 /WSP 2 through sector 1 /WSP n. There may be only partial or even no overlap between the connectivity assignments due to the variable simulcast ratios across the differing protocols. Sector 2 /WSP 1 not only does not fully overlap with sector 2 /(WSP 2 through n) but also may also partially overlap with sector 1 /(2 though n) in RAN assignments.
[0063] Referring in particular to the example shown in FIGS. 6 and 7 , WSP or tenant 1 is operating with a CDMA protocol and therefore is simulcasting a group of 8 RANs within a total number of 24 RANs 50 . Each RF sector is connected to a different grouping of 8 RANs. The illustrated drawing in FIG. 8 is for a group of 24 contiguous cells showing how the three tenants may share them.
[0064] Tenant 2 is operating with a simulcast group size of 5. Thus 5 different RANs are allocated to each of the 5 sectors for this tenant. Note that since simulcast number of 5 is not an integer divisor of the number of cells in the RAN group, that number being 24 in this example, sector 3 has only 4 cells allocated to it. Tenant 3 is operating with the simulcast group size of 3 and thus is operating with 8 sectors, each having 3 RANs associated with it.
[0065] The hub interconnect in FIG. 6 then selects RAN 50 simulcast groupings for each sector based upon the desired groupings desired for each tenant. This permits for equalization of the radio frequency link budgets in each RAN 50 group.
[0066] NMS 60 distributes individual alarms to the appropriate tenants, and maintains secure transmission for each tenant, whereas each tenant 15 is provided access to only their own respective system, for monitoring and control purposes. The open access product allows an operator to customize the RAN 50 RF parameter settings to control the radio link environment, such as signal attenuation, gain, and other methods for strong signal mitigation.
[0067] In sector configuration of the system, the Hub/RAN ratio is configurable from 1 to 8 RANs per BTS sector. The RANs 50 is remote configurable through the open access operator's NMS 60 , to support what is commonly referred to as sector re-allocation. The sector allocation is defined by the hosted wireless service provider's traffic loading analysis and controlled by the inputs from the specific tenant's NMS 15 via the open access system 10 intranet 18 .
[0068] The actual RAN 50 cell radius will be largely a function of final antenna radiation center above ground.
[0069] Returning attention now to FIGS. 1 and 2 briefly, in general, the data link uses one or more fiber optic connections between a hub 35 and one or more RAN's 50 . Data link uses a mix of electrical multiplexing, wavelength multiplexing, and multiple fibers to support the bandwidth requirements of the configuration in a cost-effective manner. Data link design should optimize its cost by using the best combination of different multiplexing schemes based on physical fiber costs, leased fiber costs and technology evolution. Data link supports whole RF band transportation (digitized RF), IP packets, and other traffic as need for open access data transmission, system management and control.
[0070] The data link 40 connects a Hub 35 and multiple RAN's 50 using either a Ring or Star network topology, or possibly a mix of the two. In one configuration, open access system 10 should support up to, for either a ring or star topology, at least several miles of fiber length. The actual fiber lengths will be guided by optical path link budgets and specific RF protocol limits.
[0071] Referring to FIG. 8 , in addition to combining digitized RF for common transport, this invention allows the combination of digitized RF with conventional packet data (e.g. IP Packets). This allows the concurrent support of packet driver wireless radios 59 co-located at the RANs with RAN slices 52 , the latter which support BTSs 20 . The data radios 59 do not require a BTS 20 at the hub.
[0072] The data link is available to support connecting fixed wireless data radios 59 fitted in a RAN 50 to a centrally located router in HUB site 30 . In one configuration, IP packet traffic provides 10 Mbps, scalable up to 100 Mbps, to be shared amongst the multiple RAN data tenants. Networking architecture supports modularity and scalability for increased data rates. The data link supports multiple data radios at 1 to 25 Mbps data rates per data radio tenant.
[0073] Referring to FIG. 9 , a utility pole antenna 86 is preferred as being unobtrusive and similar in dimension to the utility pole 80 . Antenna 86 at least blends in with its immediate surroundings. The utility pole multi-band antenna 86 typically fits at least within a 12″ diameter by 72″ tall volume. The minimum pole height to the antenna base is typically at least 31 ft. agl.
[0074] In the system the multi-band antenna capability addresses 800, 1900, and at least provides volume for wireless data bands. In a preferred configuration, the antenna is multi-band and provides radiating aperture to cover all the listed bands such as, 800, 1900, WCS/ISM/MMDS and U-NII. Antenna design, antenna sizing and performance is specific for each deployment configuration.
[0075] The system configurations are modular and scalable from a single WSP application to a multi-WSP tenancy, for both the RF transceiver assemblies and the data link configurations. The system configurations have the ability to add tenants after initial install in one-tenant steps.
[0076] While this invention has been particularly shown and described with references to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the invention encompassed by the appended claims.
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In one embodiment of a system for distributing cellular radio frequency signals, a hub unit is configured to digitize first and second analog radio frequency signals in order to generate first and second digital data, respectively, indicative of the first and second analog radio frequency signals. The first and second analog radio frequency signals are broadcast from first and second base stations, respectively, associated with first and second cellular service providers, respectively, using first and second air interfaces, respectively. The first and second digital data are transported to a radio access node from the hub unit using a shared transport medium. The radio access node is configured to reconstruct versions of the first and second analog radio frequency signals from the first and second digital data, respectively, using first and second digital-to-analog converters.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to magnetic tape recording head devices, and more particularly to a process for fabricating magnetic poles for such heads utilizing a bilayer photoresist where the pole pieces are fabricated utilizing a metal sputtering process to form a laminated NiFeN structure.
2. Description of the Prior Art
To improve the performance characteristics of magnetic tape recording systems, new materials for forming the shields and poles of magnetic read/write heads and new manufacturing processes are continually being developed. Such magnetic head materials must be particularly wear resistant, as compared to materials for other,magnetic heads, in that physical contact between the magnetic tape and the magnetic head occurs during the read/write process. Therefore, many magnetic shield and pole forming materials utilized in manufacturing magnetic heads for hard disk drives are not suitable for use in magnetic tape head devices because the materials lack the required wear resistance properties necessary for magnetic tape heads.
A material that is suitable for use in a magnetic tape head is a high magnetic moment laminate material consisting of alternating layers of nickel iron nitride (NiFeN), and iron nitride (FeN). This laminate material can be created utilizing an RF diode sputter deposition process, such as is described in “Magnetic Properties of FeAIN Films at Elevated Temperatures” by P. Zheng, J. A. Bain, and M. H. Kryder in J. Appl. Phys. 81 (8), Apr. 15, 1997. The present invention is a magnetic head for magnetic tape systems that is composed of the NiFeN/FeN laminate material and a method for manufacturing it.
The manufacturing method of the present invention is an additive process. That is, generally, utilizing photolithographic techniques, a resist layer is formed on a substrate and holes or trenches of a desired shape are formed in the resist layer. A desired metal (or other material) layer is then deposited on top of a resist layer such that it fills the holes and trenches. Thereafter, the resist (along with the metalization layer on top of the resist) is next removed, such that the desired feature within the holes and trenches remains. This additive process is contrasted with a subtractive process which generally starts with the deposition of a metalization layer, followed by photolithographic steps which result in blocks of resist formed above areas of the metalization layer that are desired to be retained. Thereafter, the metalization layer is removed in all uncovered areas, leaving the portions of the metalization layer that are covered by the resist. The resist is then removed such that the desired metalization features remain. While the additive and subtractive processes generally described above may yield the same ultimate result, they are significantly different with regard to materials utilized, process parameters utilized and their suitability in the manufacturing of a particular device.
With regard to the NiFeN/FeN laminate metalization layers utilized in the present invention, the use of a subtractive process is generally unsuitable for manufacturing purposes because of the large quantity of NiFeN/FeN that must be removed, and particularly because the removal of the NiFeN/FeN laminate layers in a subtraction process must be accomplished utilizing a dry etching process, such as an ion beam etching process, which can result in the redeposition of removed material and significant clean up problems that result therefrom, as is well known to those skilled in the art. Wet chemical etching of the NiFeN/FeN, an alternative subtractive process, is not practical for manufacturing because the NiFeN and FeN layers etch at different rates, leaving ragged, poorly defined edges in the final patterned structure. Therefore, the present invention utilizes an additive process and, significantly, it utilizes a bilayer liftoff resist, as is generally known to those skilled in the art, which enables the removal of the NiFeN/FeN laminate utilizing a chemical solvent, thereby avoiding any redeposition problems and creating a manufacturing process that is suitable for commercial product development. Such a bilayer liftoff process is generally taught in U.S. Pat. No. 5,532,109, entitled: Azo Dyes as Adhesion Promotion Additive in Polydimethylglutarimide, issued Jul. 2, 1996 and naming as inventors Mohammad T. Krounbi, Alfred Renaldo (an inventor hereof) and Dougas Werner, and assigned to International Business Machines Corporation, the assignee hereof.
SUMMARY OF THE INVENTION
The magnetic tape recording head of the present invention is formed with magnetic poles that are comprised of a laminated NiFeN/FeN structure. The method for fabricating the magnetic poles utilizes an additive photolithographic technique including a bilayer liftoff resist. In this fabrication method magnetic pole trenches are formed in the bilayer liftoff resist such that an undercut exists in the liftoff layer. Thereafter, the NiFeN/FeN laminated structure is sputter deposited into the trench, followed by the wet chemical removal of the bilayer resist.
It is an advantage of the magnetic tape recording head of the present invention that it is fabricated with a laminated NiFeN/FeN structure.
It is another advantage of the magnetic tape recording head of the present invention that it is fabricated utilizing a bilayer photolithographic technique which reduces cleanup problems.
It is a further advantage of the fabrication method of the present invention that it utilizes photolithographic fabrication technique including a bilayer liftoff resist.
It is yet another advantage of the fabrication process of the present invention that the patterned structures of the sputter deposited NiFeN/FeN are well formed and free of distortion.
It is yet a further advantage of the fabrication process of the present invention that it utilizes an additive photoresist process including a bilayer photoresist, wherein undercuts are formed in the liftoff layer, such that clean edges of the sputter deposited NiFeN/FeN poles are formed.
These and other features and advantages of the present invention will no doubt become apparent to those skilled in the art upon review of the following detailed description which makes reference to the several figures of the drawings.
IN THE DRAWINGS
FIGS. 1-4 are side cross-sectional views depicting a bilayer photoresist liftoff process of the present invention;
FIGS. 5 and 6 are side cross-sectional views of the fabrication process of the present invention that are specifically related to the NiFeN/FeN laminated magnetic poles of the magnetic tape recording head of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIGS. 1-4 are cross-sectional views generally depicting the bilayer liftoff process of the present invention for forming NiFeN/FeN high magnetic moment laminated structures. As depicted in FIG. 1, a bilayer resist 12 is formed on the upper surface 14 of a substrate 16 . The bilayer resist 12 includes a first layer 20 , termed a release layer, and a second, upper layer 24 that is composed of a suitable photoresist for use in photolithographic processing. The release layer 20 is preferably composed of Polydimethylglutarimide (PMGI), a polymer supplied by Microlithography Chemical Company (MCC) of Boston, Mass. While many photoresists may be effectively utilized as layer 24 , a preferred photoresist is a negative i-line resist (i-300) as is supplied by the Shipley Company of Marlboro, Mass.
Thereafter, as depicted in FIG. 2, using well known photolithographic techniques, the device is baked, photoexposed, baked again and developed with a suitable developer that removes the unexposed photoresist in the photoresist layer 24 . The developer may also remove portions of the PMGI release layer 20 , or, alternatively the PMGI layer can be separately developed. Using either developing step the release layer 20 is developed to expose the substrate surface 14 through a hole or trench 28 that has been formed through the resist layer 24 and release layer 20 . A desirable undercutting 30 of the release layer 20 beneath the resist layer 24 occurs during the development of the release layer 20 . The undercut 30 is desirable because it causes the overhanging resist edge 34 to shield the outer portions 38 of the substrate surface 14 from unwanted deposition of the material that is next deposited.
Thereafter, as depicted in FIG. 3, material (the NiFeN/FeN laminate) is deposited onto the structure such that portions 50 of the material are deposited on the upper surface of the resist layer 24 and portions 54 of the material are deposited into the hole or trench that has been photolithographically formed. Due to the resist overhang 34 , the material 54 that is deposited into the photolithographic trench forms relatively smooth edges 60 . Significantly, if the undercut 30 did not exist, then the walls 64 of the trench would extend in a relatively straight manner down to the substrate surface 14 , and deposited material would exist on those wall portions, just as deposited material 70 exists on the vertical walls 64 of the resist layer 24 . If such deposited material existed, it would be difficult to remove it, thereby complicating the manufacturing process. Therefore, the undercuts 30 beneath the overhang 34 of the resist layer 24 serve to provide good, clean edges 60 to the deposited structure 54 .
Following the material deposition step depicted in FIG. 3, an organic solvent which dissolves the PMGI release layer 20 is utilized to remove all of the unwanted material; that is, the release layer 20 , the resist layer 24 and the material 50 on top of the resist layer, such that the desired structure 54 remains on the surface 14 of the substrate 16 , as depicted in FIG. 4. A suitable organic stripper for PMGI is N-methyl pyrrolidone (NMP).
Having generally described the bilayer liftoff process of the present invention, the particular process materials and parameters of the present invention as utilized in the manufacturing of a magnetic head for magnetic tape systems are next discussed with the aid of FIGS. 5 and 6.
FIG. 5 is a cross-sectional view depicting the magnetic pole pieces of a magnetic head 100 of the present invention. As depicted in FIG. 5, an electromagnetic shield 104 is deposited upon a substrate base material 108 utilizing standard deposition techniques such as electroplating, sputter deposition and the like. An insulation layer 112 is thereafter formed on the shield 104 utilizing standard techniques. Thereafter, a first magnetic pole (P 1 ) 120 is fabricated on the surface 124 of the insulation layer utilizing the bilayer liftoff fabrication process described hereinbelow. The P 1 pole is composed of a NiFeN/FeN laminate structure.
FIG. 6 is a cross-sectional view depicting the bilayer liftoff resist structure of the P 1 pole fabrication process. As depicted in FIG. 6, a PMGI release layer 20 is formed on the upper surface 124 of the insulation layer 112 , and the photoresist layer 24 is formed on top of the release layer 20 and a hole or trench 28 has been photolithographically formed such that the undercuts 30 are formed in the release layer 20 beneath overhanging portions 34 of the resist layer 24 . NiFeN/FeN laminate material is then deposited such that the P 1 pole piece 120 is formed within the hole or trench 28 , and NiFeN/FeN laminate material 50 is also deposited upon the upper surface of the resist layer 24 .
As indicated above, the undercut 30 in the release layer 20 provides a valuable function in preventing the formation of edge deposits, or fences. In the preferred embodiment, where the P 1 pole 120 has a thickness of approximately 1.5 μm, the release layer 20 is formed with a thickness h of approximately 2.0 μm, the resist layer 24 is formed with a thickness of approximately 1.0 μm, and the undercut 30 is formed with a length of approximately 2.0 μm from the edge 130 of the resist layer 24 at the hole or trench 28 . While a deeper undercut 30 is permissible, although unnecessary in the manufacturing process of the present invention, an undercut 30 having a length that is less than approximately 50% of the thickness h of the release layer 20 will generally result in the unwanted deposition of fence material, thereby creating manufacturing and quality control difficulties.
After the P 1 pole 120 has been deposited, the release layer 20 and material on top of it are chemically removed, as described hereabove. Thereafter, a write gap layer 136 is formed upon the top surface 140 of the P 1 layer utilizing well known deposition techniques. Thereafter, a P 2 pole layer 145 of laminated NiFeN/FeN approximately 1.5 μm thick is formed upon the write gap layer again utilizing the bilayer liftoff manufacturing process described hereabove. It is to be noted that other and intervening well known process steps utilized in fabricating additional magnetic tape head structural features are performed between or after the formation of the P 1 and P 2 poles as described hereabove, as would be well known to those skilled in the art. A detailed description of process steps involved in creating such well known additional tape head structures is not necessary to an understanding of the present invention, and is therefore not presented herein.
The high magnetic moment NiFeN/FeN laminate structure of the magnetic tape head of the present invention is deposited in a multi-layer sputtering process utilizing conventional RF diode, RF magnetron, or DC magnetron methods. Depending on the detailed deposition process, the wafer temperature may reach 150° C. The compressive stress in the NiFeN/FeN laminated film may be in the range from 500 MPa to 1.5 MPa according to the sputtering method and process conditions. A robust photoresist liftoff process is therefore required, wherein no movement or flow of the photoresist occurs under these process conditions. Additionally, a bilayer liftoff process facilitates the clean removal of both the robust photoresist layer and the NiFeN/FeN layers that are deposited upon the resist. The bilayer resist process is well known in the semiconductor processing industry, and has been applied in the manufacture of hard disk drive magnetic heads (termed DASD heads), and in both of these applications the thickness of the release layer is significantly less than that employed in the present invention because the metallization layers to be lifted off are considerably thinner. Specifically, whereas the release layer thickness in typical DASD manufacturing processes is approximately 0.2-0.3 μm, the thickness of the release layer 20 in manufacturing the tape heads of the present invention is approximately 2.0 μm. Such a thick release layer consequently requires an increased undercutting to avoid edge deposition or fencing of deposited material. In the present invention, the recommended undercutting is approximately equal to the thickness h of the release layer.
Another critical difference between prior art bilayer resist applications in the semiconductor and DASD head industries and the present invention is that the combined effects of NiFeN/FeN laminated film stress and thickness and wafer temperature during deposition place a significantly greater demand on the mechanical properties of the photoresist layers in the present invention. As thickness, stress, and temperatures increase, the forces that tend to distort the patterned structures in the photoresist in an unacceptable way increase as well.
The following examples illustrate the robustness of various bilayer photoresist structures with respect to fencing of deposited material and pattern distortion due to flow or deformation of the resist structure during processing:
A 125 mm (5 in) ceramic wafer was first coated with a dyed thick film version (SFN11) of polydimethylglutarimide (PMGI) from Microlithography Chemical Corp (MCC). Spinning at 1500 rpm (60 sec) and soft-baked on a hotplate (165-170 C., 450 sec) gave approximately a 2.0 μm thick release layer film. In a second step, a negative working photoresist, Ultra i-300 (Shipley corp.) was applied to the wafer at 2600 rpm (60 sec) and soft-baked at 105-110° C. (450 sec) to give a 1.0 μm thick resist layer film. The bilayer of PMGI and photoresist (approximately 3.0 μm total film thickness) was exposed to a mercury lamp (g-h lines) using an Ultratech stepper (UTS-1700) at doses ranging between 800-1200 mj/cm-2. After exposure the wafer was post-expose baked (PEB) at 105-110° C. (450 sec) and puddle developed (6×50 sec) in a dilute KOH developer (0.16 N, MP 2401 from Shipley Company diluted 1:6 in water, 22° C.). An acceptable undercut of the PMGI layer was generated by this method and determined to be 1.0-2.0 μm by optical inspection.
The photoprocessed wafer was cleaned with a hydrogen/nitrogen plasma for 2 min in a barrel asher. Next, the high moment NiFeN/FeN laminate was deposited using a Balzers Z660 sputtering system. The laminate has the following structure: 200 Å NiFe/(600 Å FeN/200 Å NiFeN) 19X , in which the subscript denotes the number of repetitions of the alternating FeN and NiFeN layers. The total laminate thickness was approximately 1.5 μm. In this process the NiFeN layers are deposited by RF diode reactive sputtering from a Ni81.9Fe 18.1 (wt %) target at 2.0 kW power, 1.0×10 −2 mbar pressure, −35 V substrate bias, 99 sccm Ar gas flow and 6 sccm N 2 gas flow. The NiFe base layer is deposited using the same conditions except that no N 2 gas is used. The FeN layers are sputtered from an Fe target by reactive RF diode sputtering at 2.0 kW power, 1.0×10 −2 mbar pressure, −35V substrate bias, 58 sccm Ar gas flow and 10 sccm N 2 gas flow. The wafers were heat sunk to the pallet using Indium foil, and the pallet in turn is heat sunk to a water cooled substrate table. The substrate temperature rises to approximately 120° C. in the deposition. A magnetic field is applied to each wafer by permanent magnets to set the easy axis orientation of the film.
The wafer deposited with high moment laminate films was treated to hot NMP (55-60 C.) in a tank with sweep powered ultrasonics for 30-45 min. The excess laminate was removed with minimal metal fencing as was determined by optical inspection.
While the present invention has been shown and described with reference to certain preferred embodiments, it is contemplated by the inventors that those skilled in the art will develop certain alterations and modifications therein that nevertheless include the true spirit and scope of the invention. It is therefore intended that the following claims cover all such alterations and modifications that nevertheless include the spirit and scope of the present invention.
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The magnetic tape recording head of the present invention is formed with magnetic poles that are comprised of a laminated NiFeN/FeN structure. The method for fabricating the magnetic poles utilizes an additive photolithographic technique including a bilayer liftoff resist. In this fabrication method magnetic pole trenches are formed in the bilayer liftoff resist such that an undercut exists in the liftoff layer. Thereafter, the laminated NiFeN/FeN structure is sputter deposited into the trench, followed by the wet chemical removal of the bilayer resist.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to the treatment of hydrocarbons and more specifically relates to separating and recovering ethane and higher boiling hydrocarbons from the methane in a natural gas stream which has been sweetened by removal of acidic components, such as CO 2 , H 2 S, RSH, RSSR, and ammonia.
2. Review of the Prior Art
Raw natural gas as it originates from subterranean reservoirs, either out of solution from crude oil or unassociated with crude oil, can be classified as rich natural gas, rich gas, or lean natural gas. These terms are relative.
Rich natural gas contains a mixture of individual gaseous constituents, some of which can be liquified at atmospheric temperatures and pressures when isolated. The quantities of each component vary from one gas to another, with methane as a usual majority component. Other hydrocarbon components include ethane, propane, isobutane, normal butane, isopentane, normal pentane, hexane, heptane, octane, and nonane, in the order of increasing molecular weight and increasing boiling temperature. Usually, natural gases contain some gaseous contaminations such as nitrogen, carbon dioxide, carbonyl sulfide, hydrogen sulfide, mercaptans, disulfides, ammonia, and water. However, all of these impurities except water and nitrogen are removed by sweetening. Such a sweet natural gas stream is the subject of this invention.
"Lean natural gas" is a term applied to a natural gas which consists of only the lower molecular weight gaseous components, consisting for the most part of methane with variant quantities of ethane, propane, and only very small traces of higher molecular weight components, if any. Such a lean natural gas can occur naturally but generally results from processing a rich natural gas in accordance with recognized industrial methods.
Such a lean natural gas stream, if it contains a high proportion of ethane and propane, may be treated according to the method of this invention to produce desired quantities of these hydrocarbons.
The sweet natural gas stream which is preferably handled according to the method of this invention contains nitrogen, methane, ethane, propane, iso and normal butanes, iso and normal pentanes, hexane, heavier hydrocarbon components, and water. However, there are no acid gases or other acidic impurities, such as CO 2 , COS, H 2 S, RSH, RSSR, and ammonia, unless a terminal treatment step is added to the process.
If a natural gas is mostly methane with minor concentrations of ethane, propane, and butanes, it is called a "dry gas", meaning that it has a very low hydrocarbon dew point. The larger the quantity of heavier hydrocarbons such as pentane and higher homologs, e.g., to C 18 , the higher is the hydrocarbon dew point. Frequently, the heavier hydrocarbons are present in sufficient quantities to justify passing the gas through a "gasoline extraction plant" which removes ethane and propane in addition to the heavier hydrocarbons. In some instances, the hydrocarbon dew point is high enough to require a "dew point control station" which removes enough of the heavy hydrocarbons to lower the dew point sufficiently to permit pipeline transmission but does not remove as much of the heavier materials, in addition to the large percentage of the propane and ethane, as is removed by a gasoline extraction plant. Furthermore, the gas coming from the wellhead is usually saturated with water which must be largely removed in order to prevent the formation of ice and hydrates or the accumulation of water which can block the flow and cause corrosion.
Numerous processes have been used to extract liquids from natural gas streams. These processes include oil absorption, refrigerated oil absorption, simple refrigeration, cascaded refrigeration, Joule-Thompson expansion, cryogenic turbo-expansion, and absorption by oxygen-containing liquids.
Oil absorption processes, such as that described in U.S. Pat. No. 2,428,521, are the original separation processes and commonly recover butanes plus heavier components, with some amounts of propane, from natural gas streams. Refrigerated oil absorption processes are similar to the absorption processes except that the oil is cooled by external refrigeration before absorption of liquid components from the gas streams. The recoveries of propane plus components are improved by cooling the absorption oil. Plants using these processes are extremely complex and energy extensive.
A simple refrigeration process includes cooling the gas directly with a single refrigerant, such as propane. Condensed liquids are separated from the gas and are pumped to product pipelines. The recoveries of a simple refrigeration system are better than those of oil absorption units. A cascaded refrigeration process includes several levels of refrigeration, using at least two refrigerants, such as ethane refrigerant cascaded into a propane refrigerant cycle. The recoveries of cascade refrigeration systems are quite good, but units using these processes are not very economical because of high operating and installing costs.
The Joule-Thompson process is a step forward because it uses the refrigeration from the components of a natural gas stream by letting down its pressure. When the residue gas is required at essentially the same pressure as the inlet gas, however, this process becomes quite expensive. A cryogenic expander process has less energy consumption than a Joule-Thompson process for a given recovery, primarily because a portion of the total recompression of residue gas is provided by the turbo-expander. The Joule-Thompson and cryogenic expander processes are primarily used when ethane is to be extracted from natural gas streams. These processes can achieve ethane recoveries as high as 85% to 90%.
In summary, the oil absorption, refrigerated oil absorption, simple refrigeration, and cascaded refrigeration processes operate at the pipeline pressures, without letting down the gas pressure, but the recovery of desirable liquids (ethane plus heavier components) is quite poor, with the exception of the cascaded refrigeration process which has extremely high operating costs but achieves good ethane and propane recoveries. The Joule-Thompson and cryogenic expander processes achieve high ethane recoveries by letting down the pressure of the entire inlet gas, which is primarily methane (typically 80-85%), but recompression of most of the inlet gas is quite expensive.
Under poor economic conditions when the liquid ethane price as petrochemical feedstock is less than its equivalent fuel price and when the propane price for feedstock usage is attractive, the operator of a natural gas liquid extraction plant would prefer to maximize the propane recovery while minimizing the ethane recovery but is limited in operating choice. The refrigeration process, which typically recovers 80% of the propane, requires the recovery of typically 35% of the ethane in the inlet gas. In order to boost propane recovery to the 95+% level, cascaded refrigeration, Joule-Thompson, cryogenic, and turbo-expander processes would be required simultaneously to boost the ethane recovery to 70+% at a considerably larger capital investment.
Absorption processes are available that employ liquids other than hydrocarbon oils for removal of acidic components including H 2 S and CO 2 , water, and heavier hydrocarbons which are lost. These liquids comprise propylene carbonate, N-methyl pyrrolidone, glycerol triacetate, polyethyleneglycol dimethyl ether, triethylolamine, tributyl phosphate, and gamma butyrolactone. In particular, U.S. Pat. No. 3,362,133 is directed to sour natural gas mixtures containing H 2 S and CO 2 and teaches the selection of any dialkyl ether of a polyalkylene glycol as the ether component of a solvent for withdrawing H 2 S. A mixture of six dimethyl ethers of polyethylene glycol (DMPEG) is said to be effective. The solvent/gas ratio is 0.1 to 1.8 pounds of solvent per standard cubit foot (scf) of H 2 S to be absorbed because less than this amount will not effectively remove H 2 S and larger amounts of CO 2 . The H 2 S-rich and CO 2 -rich DMPEG solvent is flashed at 15-500 psi lower pressure than in the absorber (preferably, 65 psi lower pressure) in a flash tank which produces gas having substantially all of the CO 2 and one-fourth of the H 2 S. This gas is returned to the absorber. The DMPEG solvent is heated, reduced in pressure, and passed through a packed column as air is passed upwardly. The solvent must contain no more than 0.001% H 2 S when it returns to the absorber. The CO 2 and H 2 S which are vented from the top of the stripping column contain dissolved hydrocarbons which represent a significant loss.
U.S. Pat. No. 3,770,622 relates to treatment for natural gas to remove three troublesome components: CO 2 , H 2 S, and hydrocarbons heavier than methane. The preferred solvent is propylene carbonate. Polyethylene glycol dimethyl ether may be passed in counter-flowing contact with a natural gas mixture to remove CO 2 and/or H 2 S acid gases plus C 2 -C 18 hydrocarbon components from methane gas streams. CO 2 , H 2 S, and light hydrocarbons are partially separated from the solvent by flashing. Liquid hydrocarbons, C 4 and heavier, having gasoline value are then separated in a settler from liquid solvent and from a vaporphase mixture of C 2 -C 12 hydrocarbon vapor, H 2 S, and/or CO 2 . In the Example, the three flash streams together contain 43.76% of C 2 -C 12 hydrocarbons which represent a signficant loss of desirable hydrocarbons with the CO 2 and H 2 S vent gases.
U.S. Pat. No. 3,837,143 describes simultaneous dehydration and sweetening of natural gas to produce therefrom a purified natural gas having a low dew point and a low sulfur content by using a normally liquid dialkylether of a polyalkylene glycol ether containing 2-15% water by weight in direct contact with the natural gas. In this process, the natural gas is significantly dry with respect to C 2 + hydrocarbons. Example 1 illustrates a loss of 74% of C 2 + hydrocarbons with the CO 2 and H 2 S vent stream while Example 2 shows a loss of 11.6% for C 2 + hydrocarbons. These losses, when applied to a wet natural gas stream, indicate a significant economic penalty for sweetening wet gases with DMPEG.
U.S. Pat. No. 4,052,176 relates to a synthesis gas and teaches further purification thereof with dimethyl ether of polyethylene glycol to absorb remaining CO 2 , H 2 S, and COS. In this process DMPEG is used to treat a stream that does not contain C 2 + hydrocarbons.
U.S. Pat. No. 4,070,165 teaches sweetening a raw natural gas by countercurrent contact with a lean amine solution, dehydrating by contact with a dry glycol stream, and removal of heavier hydrocarbons (after depressurizing) by scrubbing with a lean hydrocarbon stream which is then fractionated to produce methane, ethane, and propane. Dimethyl ether of polyethylene glycol is mentioned as useful for both water and H 2 S removal. The natural gases which are suitable for liquefaction and which exist at pressures higher than 800 psig are usually dry and contain few C 2 + heavier hydrocarbons. This patent also teaches the preference of amines over DMPEG for removing the H 2 S and CO 2 contents of the raw natural gas stream in order to eliminate hydrocarbon losses with CO 2 and H 2 S vent streams.
As presented at the 59th Annual Gas Processor's Association Convention, Mar. 17-19, 1980, in a paper entitled "High CO 2 -High H 2 S Removal With SELEXOL Solvent" by John W. Sweny, the relative solubility in DMPEG of CO 2 over methane is 15.0 while that of propane is 15.3. The relative solubility of H 2 S over methane is 134 in DMPEG vs. 83 for normal pentane in DMPEG. The relative solubilities in DMPEG of iso and normal butanes and iso pentanes are in between those of propane and H 2 S. Such data indicate that if CO 2 and H 2 S are present in a natural gas stream which contains C 2 + heavier hydrocarbons which are desirable for petrochemical industry feedstocks, substantial quantities of C 2 + hydrocarbons will be lost with CO 2 and H 2 S vent streams when the natural gas is treated with DMPEG.
Sweet natural gas is usually saturated with water at its ambient temperature which may have a range of 75°-120° F., so that its water content may vary from 20 pounds to more than 50 pounds per million standard cubic feet. However, difficulties are frequently met while pumping such natural gas unless the water content is reduced to a value of less than 12 pounds, preferably less than 7 pounds, of water per million standard cubic feet of natural gas. In terms of dew point, a natural gas having a dew point of 30° F., preferably 20° F. or lower, is generally considered safe for transportation in a pipeline. Dehydration can be carried out under a wide range of pressures from 15 to 5000 psig, but it is usually carried out at pipeline pressures of 500-1500 psig and generally near 1000 psig.
There is nevertheless a need for a process wherein ethane and heavier hydrocarbons and water can be simultaneously removed to a selected degree from methane contained in a sweet natural gas stream without inclusion of steps involving drying thereof. There is further a need for a process wherein propane and heavier hydrocarbons can be extracted from a sweet natural gas stream without the need to extract significant quantities of ethane. There is further a need for a process wherein any natural gas, from very sour to entirely sweet, can be handled by the same equipment while simultaneously dehydrating the gas and recovering the heavier hydrocarbons.
SUMMARY OF THE INVENTION
The object of this invention is to provide an absorption process for removing ethane plus heavier hydrocarbon components from a sweet natural gas stream by contact with an alkyl ether of polyethylene or polypropylene glycol or mixtures thereof according to an extremely flexible wide range of ethane recoveries without requiring additional equipment therefor.
An additional object is to provide a process for removing C 3 + components from a sweet natural gas stream by contact with the same solvent without requiring the recovery of ethane from this natural gas stream and while keeping high recovery levels for C 3 + components.
Another object is to provide a process for removing C 2 + components, water, and acid components from a sour natural gas stream by contact with the same solvent and to separate all such components from the solvent and in the same equipment and then to separate the acid components from the C 2 + components.
In accordance with these objects, the process of this invention uses dimethylether of polyethylene glycol for extracting ethane and heavier hydrocarbon components and water, if present, from a sweet natural gas stream, at any desired ethane recovery from 2% to 98%. The inlet gas pressure can range from 300 psig to 1300 psig and from an ambient temperature of 80° F. to 120° F.
It is well know that the ratio of ethane to methane can be varied at will by changing the flowrate of the solvent. The absorption principle leads to an alpha or relative volatility between methane and ethane of slightly less than 5 for almost all known absorption oils. However, the relative volatility between methane and ethane in the presence of dimethyl ehter of polyethylene glycol (DMPEG) is 6.4, indicating that it is more selective toward ethane than other absorption oils. N-methyl pyrollidone (NMP) and dimethyl formamide (DMF) have relative volatilities between methane and ethane of 5.3 and 8.5, respectively. However, the solubility of hydrocarbons in NMP is 0.03 standard cubic feet per gallon (SCF/gal) and in DMF of 0.04 SCF/gal; these are low when compared to 1.0 SCF/gal for DMPEG. Therefore, it is the combination of improved selectivity towards ethane and the hydrocarbon loading capacity of dimethyl ether of polyethylene glycol that makes it a superior absorption solvent for separating and recovering the components of a sweetened natural gas stream that are heavier than methane.
The most suitable range of molecular weight for dimethyl ether of polyethylene glycol is 146 to 476, containing 3-10 ethylene units. The glycol can be branched, such as polypropylene glycol. The basic difference between the behaviors of ethyl and propyl groups is the affinity for water for the ethyl and greater affinity for hydrocarbons for the propyl group. A mixture of dimethyl ethers of polyethylene and polypropylene glycol in various combinations is consequently suitable for recovering ethane plus heavier hydrocarbons from a natural gas. In such a mixture, the content of alkyl ether of polyethylene glycol should be a minimum of 20% by volume, with alkyl ether of polypropylene glycol being limited to 80% by volume maximum.
According to this process, the inlet gas enters the extractor at the bottom and flows upward while dimethyl ether of polyethylene glycol, as solvent, enters the extractor near the top and flows downward. The gas and liquid solvent contact one another in any suitable liquid-gas contacting means, such as distillation trays or column packing. The quantity of liquid solvent that is useful is a function of contact area, inlet gas flow rate, gas pressure, and/or design recoveries of ethane plus heavier hydrocarbon components.
The gas leaving overhead from the extractor meets pipeline specifications. The liquid solvent, rich in ethane plus heavier hydrocarbon components, is let down in pressure in stages in order to reduce energy consumption. In all embodiments described hereinafter, the first stage is represented by a medium-pressure flash tank wherein some of the methane is flashed and then compressed. The liquid solvent, containing ethane plus heavier hydrocarbon components, is further let down to a lower-pressure flash tank wherein more of the ethane, propane and some butanes are flashed. These are also compressed.
In some embodiments, the liquids from the low-pressure flash tank are again let down to an atmospheric-pressure flash tank, where all the remaining hydrocarbons which are absorbed in the extractor are flashed out of the solvent and compressed, or, in one preferred embodiment, are let down directly to a vacuum flash tank where the remaining hydrocarbons are also flashed out of the solvent. Where an atmospheric flash tank is utilized, a vacuum flash tank may be selectively installed thereafter. A demethanizer column may advantageously be utilized after the vacuum flash tank.
If the inlet gas stream to the extractor contains water, the liquid in the atmospheric flash tank is composed of dimethyl ether of polyethylene glycol and water, since the relative solubility in DMPEG of water to methane is 11000 as compared to the similar relative solubility for normal heptane of 360. In order to remove this water, the liquid is pumped from the atmospheric flash tank to a solvent regenerator, wherein water is separated overhead while the pure solvent is pumped for recycling back to the extractor. Depending upon the water content of the sweet inlet gas being fed to the extractor, water may be stripped from the solvent with the help of a stripping gas such as dry compressed air, nitrogen, or methane. Alternatively, a reboiler may be required if such stripping gas is not available. If the inlet sweet gas does not contain any water, the solvent regenerator can be bypassed by recycling the pure solvent from the atmospheric flash tank to the extractor.
The gases leaving the medium-pressure and low-pressure flash tanks, after compression and cooling, are generally returned to the extractor. The gases leaving the atmospheric and vacuum flash tanks are suitably combined, if both flash tanks are used, compressed and condensed in a cooler and then stored in a storage vessel as liquids. From this vessel, the liquids are pumped to a pipeline. The off-gas from the demethanizer is compressed, cooled, and returned to the extractor.
In general, the smaller the quantity of C 5 + hydrocarbons in the natural gas stream, the higher the final flashing pressure can be. The range of pressures that are needed in a vacuum tank is in the range of 2 to 25 psia. The quantity of C 2 + hydrocarbons also affects the amount of methane that is picked up by the solvent and removed in the demethanizer. In general, the richer the feed in C 2 + hydrocarbons, the less the methane pickup will be. Consequently, when treating a very rich feed, a demethanizer is likely not to be needed.
CO 2 and H 2 S have solubilities in DMPEG that are very close to the solubilities of propane and pentane, respectively in this solvent. Therefore it is difficult to separate these acidic materials from the desirable gases when treating sour natural gas, and the prior art has tended to perform this separation before removing hydrocarbons, thereby requiring large capacity equipment and losing significant quantities of desirable hydrocarbons with CO 2 and H 2 S vent streams. Widespread usage of DMPEG has obviously been avoided. In one of the embodiments of this invention, CO 2 and H 2 S are allowed to remain with the desirable gases until final stages in the process where they are removed as liquids requiring smaller and less expensive equipment.
This treatment procedure requires the usage of substantially larger quantities of DMPEG than has been recommended by the prior art. There is, consequently, enough absorption capacity in the DMPEG stream when equilibrium is reached that the acidic materials in the recycle stream and in the sour natural gas can be completely removed, thereby producing a sweet methane-rich stream from the top of the extractor, meeting pipeline specifications. The advantage of this treatment method over those of the prior art is that a single plant can accept a very wide variety of natural gas streams, from very acidic to completely sweet, simply by utilizing the acid removal unit (e.g., an amines process) to a selective extent or even by by-passing it entirely.
The advantages of this invention are as follows:
1. low capital investment;
2. low energy and operating costs;
3. low maintenance requirements;
4. no special metallurgical requirements;
5. reduced environmental emissions;
6. simple in operation, even permitting unattended operation;
7. operable in remote locations where water is not available;
8. no freeze up problems caused by cold temperature;
9. optimum operation at essentially ambient temperature so that minimal to no insulation is required;
10. minimum heat exchange needed, so that no fouling of equipment occurs;
11. suitable operation at pipeline pressure even during pressure swings;
12. no need for catalyst, chemicals, inhibitors, or additives;
13. minimal to no need for refrigeration;
14. extremely flexible, wide range of ethane recoveries without additional equipment, based on market economics, such recoveries varying from as high as 98% to as low as 2%, i.e., operation can vary from ethane recovery to ethane rejection;
15. solvent is non-toxic, biodegradable, and environmentally acceptable;
16. solvent is non-corrosive, non-foaming, non-degrading, and hygroscopic;
17. solvent has extremely low vapor pressure, e.g., 0.002 mm Hg at 77° F., resulting in minimum solvent losses;
18. solvent does not require mixing with any other base, so that no compositions need be maintained for extraction of liquid hydrocarbon;
19. solvent has high loading capacity, thereby minimizing its circulation rate;
20. dry or water-saturated inlet gas streams can be processed;
21. operation is continuous, with no cycling of drier beds for drying and regeneration, and
22. no need to dry the gas to 1 ppm H 2 O because no cryogen is required in the process.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention may be more readily understood by referring to the drawings which diagrammatically illustrate preferred embodiments for treating both sweet and sour natural gases for removal of water and hydrocarbons heavier than methane from a wellhead natural gas stream.
FIG. 1 is a schematic flow sheet for extraction of a recycle stream and a sweet inlet natural gas stream at 300-1300 psig with dimethyl ether of polyethylene glycol (DMPEG), and recovery of liquefied C 2 + hydrocarbons by using three flashing stages and a demethanizer.
FIG. 2 is a schematic flow sheet for extraction with DMPEG of a recycle stream and a sour inlet natural gas stream at 300-1300 psig and recovery of C 2 + hydrocarbons by using four flashing stages, if necessary, with flashed products from the last two stages compressed, condensed and stored in a storage tank. The liquid hydrocarbons containing acid gas components are treated in a tail end unit using amines.
FIG. 3 is a flow sheet which is exactly the same as FIG. 1 except that there are four flashing stages, if necessary, and that all of the flashed products being fed to the demethanizer and only the overhead of the demethanizer is recycled directly to the extractor.
FIG. 4 is a flow sheet which is exactly the same as FIG. 3 except that the flashed products of the first two stages bypass the demethanizer and are recycled directly to the extractor.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1, sweet natural gas at 300-1300 psig is introduced through line 13 into extractor 11 which may be any suitable tower filled with packing or containing perforated plates or bubble plates. Solvent enters through line 55 near the top of extractor 11, and residue gas is discharged through line 12 to the pipeline at 300-1300 psig. The rich solvent in line 15 contains water, methane, and other hydrocarbon components heavier than CH 4 . The solvent in line 55 is a normally liquid dialkyl ether of a polyalkylene glycol, preferably polyethylene glycol dimethyl ether having 3 to 10 ethylene units and a molecular weight of 146 to 476, which is substantially dehydrated for maximum dehydration capacity.
Extractor 11 is maintained at about 20°-120° F., preferably 70°-80° F. Solvent is fed through line 55 at a rate sufficient to reduce the water content of the sweet natural gas to less than 12 pounds per million standard cubic feet and preferably to less than 7 pounds per million standard cubic feet. Under these conditions, the ethane and other hydrocarbon components of greater molecular weight in line 12 are reduced to a very low value. By altering the amount of solvent entering through line 55, the proportion of ethane to the predominant methane may be varied at will, but the solvent ratio is usually at 0.005 to 0.5 gallon of solvent per standard cubic foot of sweet natural gas.
The rich solvent in line 15 passes through valve 16, enters medium pressure flash tank 21 from which primarily methane and some heavier hydrocarbons are discharged through line 22 and is compressed by compressor 23. A mixture of solvent, hydrocarbon components, and water is discharged through line 25 and valve 26 and enters low pressure flash tank 31 from which a mixture of additional methane and some heavier hydrocarbons is discharged through line 32 and compressed by compressor 33. A mixture of solvent, remaining methane, ethane, and heavier hydrocarbons, and water is discharged through line 35 and valve 36, to vacuum flash tank 71 from which substantially all of the remaining hydrocarbons are discharged through line 72, compressed by compressor 73, cooled by condenser 74, and fed to demethanizer 91. A mixture of solvent, water and trace quantities of hydrocarbons is discharged from vacuum flash tank 71 through line 75, pumped by pump 76, and sent to solvent regenerator 51.
Solvent regenerator 51 is illustrated as utilizing a reboiler 59 which heats solvent, from the bottom of regenerator 51 and passing through line 54, in order to supply heat to the regenerator. The vaporized mixture of trace hydrocarbons, water, and solvent passes from the top of regenerator 51 through line 52, is condensed in condenser 53, and enters settler 61 from which solvent is discharged through line 65 and pump 66 to return to regenerator 51 as reflux. Waste water is discharged through line 68. The hydrocarbon vapors from Settler 61 leaves through line 62, is let down in pressure through valve 70, and enters vacuum flash tank 71. Water-free solvent is discharged from regenerator 51 through line 55 and pump 56, cooled in cooler 57 and returned to enter extractor 11.
The mixture of methane, ethane, propane, and heavier hydrocarbons in line 72 passes through compressor 73 and condenser/cooler 74 to demethanizer 91. Methane leaves demethanizer 91 through line 92, is compressed to a pressure slightly higher than pipeline pressure by compressor 93, is joined by the compressed mixture in line 32 and by the compressed methane with some heavier hydrocarbons in line 22, is cooled by heat exchanger 24, and passes through line 28 to enter extractor 11, thereby recycling the methane-rich recovered gas through the extractor.
FIG. 2 relates to processing a sour natural gas which is received at the same range of pressure as the sweet natural gas treated according to the process of FIG. 1. As seen in the schematic flow sheet of FIG. 2, extractor 11, medium pressure flash tank 21, low pressure flash tank 31, solvent regenerator 51, and overhead column accumulator 61 are combined exactly as in FIG. 1 and are utilized for the same purposes.
However, the solvent stream in line 35 from low pressure flash tank 31 enters atmospheric flash tank 41, producing an overhead gas stream passing through line 42, compressor 43, and condensor/cooler 74 to enter storage tank 77.
If the inlet natural gas in line 13 is relatively lean or has trace quantities of C 5 + hydrocarbons, the solvent discharge from tank 41 moves through line 45, pump 46, and valve 49 to enter solvent regenerator 51 where it is processed as described for FIG. 1. However, if the converse is true and the inlet gas is indeed high in C 5 + hydrocarbons, the bottoms from tank 41 moves through line 44 to enter vacuum flash tank 71. The overhead therefrom passes through line 72 and compressor 73 to join line 42. The bottoms from tank 71 pass through line 75 and pump 76 to join line 45.
From storage tank 77, the liquid C 2 + hydrocarbons containing acid components moves through line 78 and pump 79 to amines contactor 81 which produces a sweet product in line 82, consisting essentially of ethane plus heavier hydrocarbon liquids for pipeline shipment. The sour amines stream in line 83 is stripped in unit 85, producing a CO 2 and H 2 S leaving through line 86. The sweet amines stream returns to contactor 81 by line 87.
There is no known problem as such that exists during simultaneous removal of acid gases and heavier hydrocarbons. However, when simultaneously removing H 2 S and CO 2 with heavier hydrocarbons, the hydrocarbons recovered need some form of treatment before shipping as specification product. As discussed in U.S. Pat. No. 3,770,622 with respect to propylene carbonate, the CO 2 can be vented from a separator while the hydrocarbons heavier than propane remain in the separator as a liquid layer which can be decanted. When using DMPEG as the solvent, on the other hand, both H 2 S and CO 2 must be extracted because DMPEG is a "physical" solvent.
As described earlier, cryogenic turboexpander technology is used to obtain very high ethane recoveries. In order to carry out such extraction from inlet gas streams containing high amounts of CO 2 (greater than 0.75 MOL%), it is very important to remove CO 2 from the gas stream before subjecting it to cryogenic temperatures in order to avoid CO 2 freeze-up problems in the equipment. Also it is more desirable to remove acid gases in liquid phase than in gaseous phase due to savings of capital and operating costs.
With the process of this invention, it is possible to remove ethane plus hydrocarbons from a relatively rich CO 2 stream without freezing problems and to remove CO 2 from desirable liquids in the liquid phase by using known amines.
As taught, for example, in U.S. Pat. No. 4,070,165, suitable sweetening amines are monoethanolamine (MEA), diethanolamine (DEA), diisopropanolamine (DIPA), and diglycolamine (DGA). Although it is common practice to utilize amines in an aqueous solution ranging from 15% to 70% by weight, it is preferred to utilize another solvent, such as methanol or acetone, for forming the amine solution circulated in amine unit 80 of this invention.
Other known sweetening processes which are suitable for treating the C 2 + products in storage tank 77 are also satisfactory. Particularly suitable processes are those which utilize solid-dessicant dehydration with such materials as activated alumina, silica gel, silica-alumina beads, and molecular sieves.
The process shown schematically in the flow sheet of FIG. 3 is directed to treating sweet inlet natural gas at 300-1300 psig and is very close to that of FIG. 1 in that it comprises a medium pressure flash unit 20, a low pressure flash unit 30, a vacuum flash unit 70, and a demethanizer unit 90. However, it additionally comprises an atmospheric flash unit 40, as in FIG. 2.
Unlike either FIG. 1 or FIG. 2, moreover, overhead discharge line 22 and overhead discharge line 32 join overhead discharge line 42, which is previously joined by overhead vacuum discharge line 72 (if unit 70 is utilized), so that all products from units 20,30,40, and 70 enter demethanizer unit 90. Demethanizer 91 and reboiler 99 must be larger, in consequence, than in the process of FIG. 1 for the same inlet quantity of sweet natural gas entering through line 13. On the other hand, all products of units 20,30,40, and 70 are treated alike, and very small quantities of heavier hydrocarbons are retained by the gas leaving in line 12.
The off gases from demethanizer 91 leaves through overhead discharge lines 92, is brought up to pipeline pressure in compressor 93, cooled in condenser 94, and returned to the lower portions of extractor 11.
The process shown schematically in the flow sheet of FIG. 4 is directed to treating sweet inlet natural gas at 300-1300 psig which enters extractor 11 through line 13. The process includes extractor unit 10, medium pressure flash unit 20, low pressure flash unit 30, atmospheric pressure flash unit 40, vacuum flash unit 70, solvent regenerator unit 50, and demethanizer unit 90, so that it is exactly like the process of FIG. 3 except that discharge lines 22 and 32 join discharge line 92 for cooling of all compressed products in condenser 24 and return to extractor 11 in combined line 28.
EXAMPLE
An ethane recovery plant, utilizing the process of FIG. 1, is designed and put into operation to treat one million standard cubic feet per day (1 MMSCFD) of dry sweetened natural gas for 95% ethane recovery. The composition of the natural gas entering extractor 11 of extractor unit 10 is as follows:
______________________________________Component MOL %______________________________________Nitrogen 2.02Methane 80.62Ethane 9.69Propane 4.83ISO-Butane 0.50N--Butane 1.45ISO-Pentane 0.30N--Pentane 0.37Hexane Plus 0.22 100.00Water Content 169 lbs/MMSCF dry gasInlet Pressure 625 psiaInlet Temperature 120° F.______________________________________
Sweetened natural gas stream 13 enters extractor 11 near its bottom. A recycle stream 28 also enters the extractor near the bottom. The combined gases from streams 13 and 28 flow upward in the extractor where they are contacted by lean solvent stream 55 flowing downwards. The molar ratio of solvent to fresh feed stream 13 is of the order of 1.36. Ethane and heavier liquids present in the inlet gas stream are selectively absorbed and removed from the extractor by stream 15. The remaining natural gas leaves the extractor through stream 12 which is primarily composed of nitrogen, methane, and small amounts of ethane, depending upon the desirable recoveries of ethane. Virtually all of the propane and heavier components are removed from stream 13. Stream 15 contains about 2.1 times as many moles of methane as moles of ethane.
In order to remove methane from recovered hydrocarbons while conserving energy consumption, the pressure of stream 15 is let down from 625 psia to 400 psia in medium pressure flash tank 21 where vapor stream 22, rich in methane (about 88 MOL% methane), is separated from liquid stream 25 which contains about 30% less methane, with about 94% of ethane present in stream 15. Stream 22 is compressed from 400 psia to 630 psia for recycle back to the extractor via stream 28.
In order to further reduce the amount of methane with ethane, the liquid pressure is reduced from 400 psia to 300 psia in low pressure flash tank 31. Here stream 32, consisting of about 86 MOL% methane, is separated from liquid stream 35 which contains about 1.19 moles of methane per mole of ethane and has about 51% less methane than the amount of methane present in stream 15. Vapors leaving via stream 32 are compressed to 630 psia for recycle to extractor 11 via stream 28.
In order to separate all hydrocarbon components from the solvent, the pressure of liquid stream 35 is reduced from 300 psia to 5 psia in a vacuum flash tank 71. The hydrocarbon vapors leaving tank 71 via stream 72 are compressed to 400 psia in compressor 73 and cooled to 20° F. in condensor 74 to condense ethane plus heavier hydrocarbons as product. While condensing the heavier hydrocarbons, some methane also gets condensed and is stripped by demethanizer 91. The demethanized product meeting specifications leaves the process via stream 95. The stripped methane from stream 72 leaves demethanizer 91 via stream 92 and is compressed to 630 psia for recycle to extractor 11 via stream 28. The combined streams 22, 32 and 92 are cooled to about 120° F. and recycled to extractor 11 via stream 28.
Depending upon the ethane recovery requirements, it may or may not be necessary to recycle stream 28 to the extractor. Instead, stream 28 could bypass the extractor and leave the plant by joining stream 12. The amount of methane that is present in stream 15 depends upon the partial pressures of desirable hydrocarbon components in stream 13.
Liquid stream 75 leaving vacuum flash tank 71 contains about 1.5 MOL% hydrocarbons and water, with the rest being the solvent. This stream is pumped into solvent regenerator 51 where contained water and hydrocarbons are separated overhead. The solvent regenerator operates typically at about 20 psia. The solvent is heated to about 300° F. to completely remove water from the solvent in the solvent regenerator and is cooled to about 120° F. before returning it to the extractor via stream 55. The water content of solvent stream 55 can be as high as 2 MOL% without any detrimental effect on the performance of the extractor, which would leave the temperature to which the solvent must be heated by reboiler 59.
The water is separated from the hydrocarbon vapors in column overhead accumulator 61 and leaves the process through stream 68. The hydrocarbon vapors are recycled under its pressure via stream 62 to vacuum flash tank 71.
The operation of the process as depicted in FIG. 1 can be more clearly understood by study of the compositions of the various streams in pound-mols per hour (LB-MOLS/HR). Eleven components of 15 streams are given in the following two tables.
TABLE I______________________________________MATERIAL BALANCE FOR ILLUSTRATIVE EXAMPLEStreamNo.Compo-nents,Lb-Mols/Hr 13 55 12 15 28 22 25______________________________________Nitrogen 2.22 -- 2.22 0.11 0.11 0.07 0.04Methane 88.48 -- 88.26 25.76 25.54 7.69 18.07Ethane 10.63 -- 0.54 12.09 2.00 0.75 11.34Propane 5.30 -- Trace 5.60 0.30 0.15 5.45ISO- 0.55 -- -- 0.57 0.02 0.01 0.56ButaneN--Bu- 1.59 -- -- 1.63 0.04 0.02 1.61taneISO- 0.33 -- -- 0.33 -- -- 0.33PentaneN--Pen- 0.41 -- -- 0.41 -- -- 0.41taneHexane 0.29 -- -- 0.29 -- -- 0.29PlusWater 0.39 -- -- 0.39 -- -- 0.39Solvent -- 150.0 -- 150.00 -- -- 150.00TOTAL, 110.19 150.00 91.02 197.18 28.01 8.69 188.49LB-MOLS/HR______________________________________
TABLE II__________________________________________________________________________MATERIAL BALANCE FOR ILLUSTRATIVE EXAMPLEStream No.Components,Lb-mols/Hr 32 35 72 75 92 95 68 62__________________________________________________________________________Nitrogen 0.02 0.02 -- -- 0.02 -- -- --Methane 5.39 12.68 12.68 0.09 12.46 0.22 -- 0.09Ethane 0.71 10.63 10.63 0.44 0.54 10.09 -- 0.44Propane 0.15 5.30 5.30 0.51 Trace 5.30 -- 0.51ISO-Butane 0.01 0.55 0.55 0.09 -- 0.55 -- 0.09N--Butane 0.02 1.59 1.59 0.31 -- 1.59 -- 0.31ISO-Pentane -- 0.33 0.33 0.10 -- 0.33 -- 0.10N--Pentane -- 0.41 0.41 0.15 -- 0.41 -- 0.15Hexane Plus -- 0.29 0.29 0.13 -- 0.29 -- 0.13Water -- 0.39 -- 0.39 -- -- 0.39 TraceSolvent -- 150.00 -- 150.00 -- -- Trace --TOTAL, 6.30 182.19 31.78 152.21 13.02 18.78 0.39 1.82LB-MOLS/HR__________________________________________________________________________
It is apparent from these tables that about 30% of the 25.76 pound-mols/hr of methane that is dissolved in solvent stream 15 is returned to extractor 11 in stream 22, about 21% is returned in stream 32, and about 48% is returned in stream 92. With respect to the 12.09 pound-mols/hr of ethane that leave in solvent stream 15, about 6.2% is returned to extractor 11 in stream 22, 5.9% is returned to extractor 11 in stream 32, 4.5% is returned in stream 92, and 83.4% leaves in product stream 95. With respect to the 5.60 pound-mols/hr of propane in stream 15, 2.7% returns in stream 22, 2.7% returns in stream 32, and 94.6% is in product stream 95.
Without employing demethanizer unit 90, as in FIG. 2, it is clear that about half of the methane can become part of the product stream in line 82. Nonetheless, economic considerations, based upon product specifications, may easily obviate a need for demethanizer unit 90. Moreover, other design considerations may be important. For example, if the proportion of C 2 + hydrocarbons is unusually high, the amount of methane absorbed in the solvent is proportionately less.
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A sweet natural gas stream is stripped of water and hydrocarbon components heavier than methane to substantially any selected degree by countercurrent extraction with polyethylene glycol dimethyl ether while at pipeline pressures. The stripped natural gas meets pipeline specifications. The rich polyethylene glycol dimethyl ether is let down in pressure through selected successive stages which respectively isolate fractions that are rich in ethane, propane, butanes, and hydrocarbons heavier than butane. Lastly, waste water is removed from the solvent to regenerate the polyethylene glycol dimethyl ether. The separated gas streams of ethane, propane, butanes, and hydrocarbons heavier than butanes are individually compressed, combined, condensed and cooled to form a natural gas liquid stream, suitable for pipeline shipment. A sour natural gas stream may also be treated in the same equipment if adequate solvent quantities are employed to remove water and acidic components from the sour gas and if a sweetening unit is added to remove the acidic components from the combined liquid hydrocarbon stream.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a national phase entry under 35 U.S.C. § 371 of International Patent Application PCT/AU2007/000412, filed Mar. 30, 2007, published in English as International Patent Publication WO 2007/112487, which claims priority from Australian Provisional Patent Application No 2006901647 filed on 30 Mar. 2006, the contents of each of which is incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to a device for handling livestock and, in particular, to a device that facilitates monitoring and sorting of livestock.
BACKGROUND
[0003] In countries such as Australia, the livestock industry contributes greatly to the economical and social wellbeing of the nation. The success of the livestock industry is greatly dependent upon the ability of primary producers, such as farmers, to control and monitor their livestock to ensure an acceptable degree of livestock quality, such that the industry is sustainable.
[0004] With increased demands being placed on primary producers, livestock production and maintenance is a business requiring significant investment in both time and resources. In recent times, with the loosening of various trade restrictions between countries, there has been an increase in competition between livestock producers and suppliers, resulting in a need for farmers and other such primary producers to adopt even more efficient work practices to ensure production of a high quality at a competitive price.
[0005] The beef industry in Australia is one of Australia's major agricultural industries with about a quarter of the Australian farming establishments deriving their main income from beef cattle farming. The types of farming establishments dedicated to cattle farming varies from intensively managed small holdings in the southeast region of Australia, where water supplies and soil conditions facilitate high stocking rates, to extensive large-scale cattle stations in northern and central parts of Australia, where cattle roam relatively free with minimal regular human contact.
[0006] As discussed above, the need to monitor and assess the growth and health of individual animals is important in order to maintain a competitive and sustainable livestock industry. This is typically performed by gathering the animals and individually assessing them and, where necessary, sorting the animals for further processing. The animals are typically sorted in terms of their weight and/or age, such that they can be made available for slaughter and/or selling/export, thereby providing a source of income to the farmer. As the income is typically dependant upon the health and/or condition of the animal, regular monitoring and assessment of the animal is important to ensure maximum return to the farmer.
[0007] As such, a number of systems have been introduced to assist the farmer in individually monitoring and assessing their livestock. Such systems typically employ a variety of chutes and gates for individually directing the animals in a controlled manner through a variety of devices whereby an individual animal can be isolated from the rest of the animals for assessment and/or treatment. Assessment may include weighing, branding, applying medical treatment, and/or otherwise examining the animal.
[0008] Generally, the chutes are designed to be long and narrow in configuration so as to form an elongate space into which one animal at a time is manually driven. A head gate may be inserted into the chute to prevent the animal from progressing further while a tail gate is driven into the chute behind the animal preventing the animal from backing away from the space, thereby isolating the animal from the other animals for assessment and/or treatment. As will be appreciated, such a manual means of isolating individual animals requires considerable labor that is generally not readily available in remote locations or in instances where the farm is operated by a single farmer with limited assistance. This can also increase farm operating costs due to the need to hire workers to perform such tasks.
[0009] For this reason, automated systems have been proposed that are remotely controlled by an operator to initiate capture of an animal within a confined space. These systems can also be used with various drafting devices to provide the operator with the ability to sort the animals into two or more herds following assessment and/or treatment of the individual animals. A common problem with most existing systems is that they employ sliding of swinging gates to close in front of and behind the animal to capture the animal, which can obstruct the animals as they pass through the chutes of the various systems. Such obstructions can significantly reduce the flow of the animals passing through the chutes, thereby resulting in the need for the operator to intervene to urge the livestock to flow in an orderly manner. This is a particular problem when large volumes of livestock are being assessed and the availability of human assistance is scarce.
[0010] Further, sliding and/or swinging gates have a tendency to tilt and wedge during use, particularly when used with cattle and the like, which have significant weight and apply significant force against the hinges and rails of the gates during use. This can cause the gates to malfunction, thereby requiring repair and/or replacement. Such repair/replacement of the gates can cause significant delays and unnecessary costs to the farmer. Also, most existing gate arrangements swing or otherwise move beyond the livestock handling area or chutes and into the area occupied by the equipment operators. Such moving components can create and pose significant risks to the wellbeing of the operators.
[0011] Therefore, there is a need to provide a livestock handling system that is designed to assist the progress of animals through the system, and that is not prone to malfunction during use, and/or compromise the safety of the operator(s).
[0012] A discussion of documents, act, materials, devices, articles or the like, which has been included in the present specification, is solely for the purpose of providing a context for the present invention. It is not to be taken as an admission that any or all of these matters form part of the prior art base or were common general knowledge in the field relevant to the present invention as it existed before the priority date of each claim of this application.
SUMMARY OF THE INVENTION
[0013] According to a first aspect, the present invention is a device for receiving and confining an animal comprising:
a pen having at least two elongate walls spaced apart to define a space into which the animal is received; an entry gate assembly located at a first end of the pen and movable between an open position, which permits entry of the animal into the pen, and a closed position; and an exit gate assembly located at a second end of the pen and movable between an open position, which permits the release of the animal from the pen, and a closed position which prevents release of the animal from the receiving pen; wherein at least one of the entry gate assembly and the exit gate assembly includes a pair of door members each having a substantially vertically extending planar surface, and wherein each door member is rotatably mounted to the pen at the first and/or second end of the pen such that when the gate assembly is moved to the closed position, the door members rotate such that their planar surfaces substantially abut to extend across the first and/or second end of the pen, and when the gate assembly is moved to the open position, the door members rotate such that their planar surfaces are located adjacent a respective elongate wall of the pen.
[0018] In one embodiment, when the gate assembly is moved to the open position, the door members rotate such that their planar surfaces are substantially parallel to the respective elongate walls of the pen. In another embodiment, when the gate assembly is moved to the closed position, the door members rotate such that their planar surfaces extend substantially orthogonal to the elongate walls of the pen.
[0019] The planar surfaces of each door member may comprise a panel extending between a pair of plates. The plates may be rotatably mounted to the pen such that each door member is able to rotate about a vertical axis.
[0020] An elongate roller member may be mounted between the pair of plates so as to extend along an edge of the panel. The edge of the panel may be a distal edge of the planar surface. The elongate roller member may be free to rotate about its vertical axis.
[0021] In another embodiment, each door member is rotated between the open and closed positions by a linear actuator connected to at least one of the plates. Reciprocal movement of the linear actuator may cause the door member to rotate about its vertical axis between the open and closed positions. The linear actuator may be a pneumatic ram that is controlled by a control system to provide remote control of either or both of the entry and exit gate assembly. In another form, the linear actuator may be manually operated.
[0022] In yet another embodiment, the space into which the animal is received is adjustable to accommodate a wide variety of animal types and sizes. In one form, one or more of the at least two elongate walls of the pen may be moveable to alter the size of the space. In this regard, one or more of the at least two elongate walls of the pen may be inwardly pivotal.
[0023] According to a second aspect of the present invention, the present invention provides a gate assembly for a pen for receiving and confining an animal, comprising:
a pair of door members rotatably mounted to the pen so as to independently rotate about a vertical axis, each door member having a substantially vertically extending planar surface; and a linear actuator mounted to the pen so as to be in connection with the pair of door members; wherein actuation of the linear actuator in a first direction causes the pair of door members to rotate such that their planar surfaces extend substantially orthogonal to a direction of travel of the animal so as to close an opening of the pen, and actuation of the linear actuator in a second direction causes the pair of door members to rotate such that their planar surfaces are located substantially parallel to the direction of travel of the animal so as to open an opening of the pen.
[0027] According to an embodiment of this aspect of the invention, the planar surfaces of each door member comprise a panel extending between a pair of plates. The plates may be rotatably mounted to the pen such that each door member is able to rotate about a vertical axis.
[0028] An elongate roller member may be mounted between the pair of plates so as to extend along an edge of the panel. The edge of the panel may be a distal edge of the planar surface.
[0029] According to a third aspect, the present invention is a livestock receiving device for receiving and confining an animal compromising:
at least two side walls spaced apart to define an elongate receiving space into which the animal is received; an entry gate assembly located at a first end of the receiving space and movable between an open position, which permits entry of the animal into the receiving space, and a closed position, which prevents entry of the animal into the receiving space; and an exit gate assembly located at a second end of the receiving space and movable between an open position, which permits the release of the animal from the receiving space, and a closed position, which prevents release of the animal from the receiving space; wherein at least one of the entry gate assembly and the exit gate assembly includes at least one vertically extending gate member that is rotated between the open position and the closed position such that movement of at least one gate member does not extend beyond a perimeter of the device.
[0034] In one embodiment of this aspect of the invention, at least one of the entry gate assembly and the exit gate assembly comprises a pair of vertically extending gate members arranged proximal the side walls of the receiving space. Each of the gate members may be configured such that when they are in the open position, they are substantially parallel to the side walls along each side of the receiving space, and when they are in the closed position, they extend substantially orthogonal to the side walls.
[0035] Each gate member may comprise a panel extending between a pair of plates. The plates may be mounted to the device such that the gate member is able to rotate about a vertical axis, thereby moving the panel between an open position where the panel is substantially parallel to the side walls and a closed position where the panel extends substantially orthogonal to the side walls. A roller member may extend along an edge of the panel. The edge of the panel may be a leading edge of the panel; namely the outermost edge of the panel when the panel is rotated to the closed position. The roller member may be mounted between the plates such that it is free to rotate about a vertical axis. In this arrangement, the roller member may contact the animal as the gate member opens and/or closes, such that the gate member is able to ride over the animal.
[0036] The gate member may be rotated between the open and closed positions by a linear actuator connected to at least one of the plates. Reciprocal movement of the linear actuator may cause the gate member to rotate about its vertical axis between the open and closed position. In one form, the linear actuator may be a pneumatic ram, which is controlled by a control system to provide remote control of either or both of the entry and exit gate assemblies. In another form, the linear actuator may be manually operated.
[0037] In another embodiment, the receiving space may be provided with a weighing scale to obtain the weight of the animal received within the receiving space. In this arrangement, the device may comprise an electronic reading device to read an identification tag of an animal, such as an ear tag or an electronic chip implanted under the animal's skin, to identify the animal such that the obtained weight can be stored against the animal. A control system may store the obtained weight data with the animal to facilitate sorting of the animals into desired groups upon leaving the receiving space. In this regard, a sorting or drafting device may be arranged proximal the exit gate assembly and controlled by the control system to sort the animal upon exiting the receiving space.
[0038] In another embodiment, the receiving space may be adjustable to accommodate a wide variety of animal types and sizes. In this regard, one or more of the at least two side walls may be moveable to alter the size of the receiving space. A locking means may be provided to lock the side walls in one of a variety of positions, according to the size and/or type of animal being handled.
[0039] According to a fourth aspect, the present invention is a livestock receiving device for receiving and confining an animal comprising:
at least two side walls spaced apart to define an elongate receiving space into which the animal is received; an entry gate assembly located at a first end of the receiving space and movable between an open position, which permits entry of the animals into the receiving space, and a closed position, which prevents entry of the animal into the receiving space; and an exit gate assembly located at a second end of the receiving space and movable between an open position, which permits the release of the animal from the receiving space, and a closed position, which prevents release of the animal from the receiving space; wherein at least one of the side walls is movable with respect to another of the side walls so that the elongate receiving space can be altered to receive animals of varying sizes.
[0044] According to a fifth aspect, the present invention is a gate assembly for a livestock handling device comprising:
a vertically extending panel mounted between a pair of mounting plates; an elongate roller arranged to extend along an edge of the panel between the plates and being free to rotate about its axis; wherein the mounting plates are configured to be mounted to the device such that the panel and roller can rotate between an open and closed position.
[0048] Throughout this specification the word “comprise,” or variations such as “comprises” or “comprising,” will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.
BRIEF DESCRIPTION OF THE DRAWINGS
[0049] By way of example only, preferred embodiments of the intention are now described with reference to the accompanying drawings, in which:
[0050] FIG. 1 is a perspective view of one embodiment of the livestock handling system of the present intention;
[0051] FIG. 2 is a top view of the embodiment of FIG. 1 ;
[0052] FIGS. 3 and 4 are perspective views of the pen of the system of FIGS. 1 and 2 showing the entry gates in the closed and open positions, respectively;
[0053] FIGS. 5A and 5B are front and side views, respectively, of one embodiment of the door members of the entry and exit gates of the system of FIG. 1 ;
[0054] FIGS. 5C and 5D are top views of the door members of FIGS. 5A and 5B , respectively;
[0055] FIGS. 6A and 6B are front and rear views of the door members of FIGS. 5A to 5D in the closed position; and
[0056] FIG. 7 is a top view of the pen of FIG. 1 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0057] A livestock handling device 10 in accordance with one embodiment of the present invention is shown generally in the accompanying figures. While the device 10 will be described in relation to its use in handling cattle, it will be appreciated that the device 10 could be equally employed for handling a variety of livestock, such as sheep, pigs and the like.
[0058] As shown in FIGS. 1 and 2 , the device 10 generally comprises a pen 12 for isolating and holding an individual animal and a sorting device 14 for sorting the animals exiting the pen 12 . The cattle may be sorted into at least two herds in accordance with a variety of sorting methods, which will be discussed in more detail later in the description.
[0059] A chute 11 is provided to feed the cattle into the pen 12 in the direction of arrow A. The chute 11 is constructed such that the cattle can move in a single line towards the pen 12 , with minimal obstruction to hamper their progress. In this regard, the chute 11 could be constructed in a variety of forms, as would be appreciated by those skilled in the art. The cattle may be manually urged or prodded to travel along the chute 11 by a farmer or other individual, or the cattle may naturally progress along the chute 11 due to the orientation of the chute 11 with respect to its surroundings.
[0060] The pen 12 is in the form of an enclosure having a pair of upright side walls 21 , 22 arranged substantially parallel to the path of the cattle moving in the direction of arrow A. The walls 21 , 22 are spaced apart a sufficient distance to accommodate the cattle passing therethrough such that an individual animal can be comfortably received therebetween. The walls 21 , 22 are constructed in a manner that retains the animal within the pen 12 and that also enables a farmer to access the animal in a manner as will be discussed in more detail below.
[0061] Entry gates 24 are provided at one end of the pen 12 , proximal the chute 11 . The entry gates 24 are actuated to move between an open position that permits entry of an animal into the pen 12 , and a closed position and prevents the animal within the pen 12 from backing out of the pen 12 , as well as other animals entering the pen 12 . Exit gates 26 are also provided at an end proximal the sorting device 14 , and are controlled to move between a closed position that encloses the animal within the pen 12 , and an open position that releases the animal from the pen 12 into the sorting device 14 . Upon entry of the animal into the sorting device 14 , the animal is sorted or drafted into an appropriated holding pen or race in accordance with a desired drafting/sorting regime employed by the farmer, which is not the subject of the present invention.
[0062] As shown more clearly in FIG. 2 , the walls 21 , 22 , entry gates 24 and exit gates 26 define a space into which an animal is received so that it can be isolated from the rest of the herd for monitoring and/or assessment by a farmer. The length of the pen 12 , namely the length of the space between the entry gates 24 and the exit gates 26 (shown as X in FIG. 1 ) is sufficient to accommodate the type of animal to be assessed/monitored. In this regard, the length X of the pen 12 may vary and is typically selected by the farmer in accordance with the type of livestock to be passed through the pen 12 . In the embodiment as shown, the length X is sufficient to accommodate cattle of variable lengths.
[0063] As will be discussed below, as the cattle move through the device 10 , the operator controls the operation of the entry gates 24 to close behind the animal thereby capturing the animal in the pen 12 between the entry gates 24 and closed exit gates 26 . The entry gates 24 may be remotely actuated by the operator through a remote control pad or the like (not shown). In this regard, the opening and closing of the entry gates 24 can by synchronized to control the progress of the cattle through the device 10 .
[0064] By isolating the animal in the pen 12 as it progresses through the chute 11 to the sorting device 14 , the animal can be monitored/assessed by the farmer/operator in a variety of ways. In the embodiment as shown, the pen 12 is configured to function as a weighbox for weighing the individual animals as they pass therethrough. In this arrangement, the weight of the animal can be ascertained and recorded to provide the operator with a record of the history of the animal, which can be used to ascertain the readiness of the animal for sale, and/or the health and condition of the animal. Upon assessing the weight of the animal, the sorting device 14 can be controlled to sort the cattle according to their weight.
[0065] It will be appreciated that while the pen 12 is described in relation to a weighbox for measuring the weight of animals passing therethrough, the pen 12 could also be arranged to perform a variety of functions, for example, as a “cattle crush,” to capture the animal to assist a farmer in administering medication to the animal or branding the animal.
[0066] The sorting device 14 is arranged adjacent the exit gates 26 of the pen 12 such that when the exit gates 26 open and the animal exits the pen 12 , the animal enters the sorting device 14 . The sorting device 14 comprises an elongated chute, similar to chute 11 , having a pair of pivoting side walls 27 , 28 . The side walls 27 , 28 are positioned to direct the exiting cattle in a desired direction under the action of one or more pneumatic actuators 29 . In the embodiment as shown in FIGS. 1 and 2 , the side wall 27 is pivoted towards side wall 28 , thereby directing the exiting cattle in the direction of arrow B. It will be appreciated that by positioning the walls 27 , 28 such that they are substantially parallel with the pen 12 , the exiting animals will be directed along path C, and by positioning side wall 27 such that it is substantially parallel with pen 12 and moving side wall 28 towards side wall 27 , the animals will be directed along path D. As discussed above, the path, which the exiting cattle take, is controlled in accordance with the measured weight of the animal. However, other factors can be used to determine the desired path of the exiting animal.
[0067] A control system 5 is provided to control and coordinate the overall operation of the device 10 . The control system 5 generally comprises a central computer, such as a portable lap top computer, which controls the actuation of the entry and exit gates 24 , 26 and the weighing arrangement of the pen 12 , as well as the pneumatic actuators 29 of the sorting device 14 . In this regard, the control system 5 can be employed so that the cattle passing through the device 10 can be sorted according to their measured weight. The control system 5 may comprise a memory storage that stores and records the weight data for each individual animal to provide to the operation information pertaining to the history of the animal, together with any other pertinent information. In this regard, an electronic reader may also be mounted to the pen 12 or chute 11 to identify the animal entering the pen 12 such that the weight of the animal can be stored against that particular animal. In this regard, the animal may be provided with an identification device, such as an ear tag or implanted microchip, which is detected by the electronic reader as the animal passes the reader to identify the individual animal. Such systems are well known in the art and will not be described in further detail. It will be appreciated that the control system 5 could also be in the form of an integrated computer system provided within the pen 12 or sorting device 14 .
[0068] The control system 5 can be easily operated by a sole operator, thereby substantially reducing the requirement for additional labor to assist weighing and recording the information for each animal.
[0069] Referring to FIGS. 3 and 4 , the pen 12 of device 10 is shown in isolation. In FIG. 3 , both the entry gates 24 and exit gates 26 are shown in the closed position as is the case when an animal is positioned within the pen for weighing. The pen 12 comprises a substantially rectangular frame 20 forming a substantially rectangular holding space for holding the animal, defined by the wall 21 , 22 and gates 24 and 26 . The holding space is designed to accommodate the animal as securely as possible and to prevent the animal from turning around or significantly moving within the holding space. Such an arrangement reduces the likelihood of the animal causing harm or injury to itself by becoming cast or stuck within the pen 12 , and also reduces the likelihood of the animal causing damage to the pen 12 as a result of moving within the holding space.
[0070] As is shown in FIG. 3 , the upper portion 25 of the walls 21 , 22 are substantially open and comprise an enclosed lower portion 23 made from a sheet of galvanized steel or the like. The open upper portion 25 is in the form of one or more steel bars. Such an arrangement provided in the upper portion 25 reduces the likelihood of any portion of the animal, such as the animal's legs, protruding or otherwise extending through the wall 21 , 22 , as the enclosed lower portion 23 leaves no exposed gaps through which limbs can extend. This is particularly important if the animal becomes agitated and attempts to kick-out when in the pen 12 . The open upper portion 25 provides the operator with the ability to access the animal to administer medication or the like to the animal as required.
[0071] As will be appreciated, cattle sizes can vary depending on a variety of factors, in particular the age of the individual animals. Hence, the holding space of the pen 12 , is generally designed so as it can readily accommodate the largest cattle sizes. In many instances, particularly where calves are being weighed and handled, the holding space of the pen 12 may be too large for the calves. Such an overly large holding space, can allow the animal to move around within the holding space of the pen, increasing the likelihood of the animal causing damage to the pen 12 or causing injury and harm to itself.
[0072] As shown in FIG. 4 , in order to deal with variable cattle sizes, the enclosed lower portion 23 of the side wall 22 is pivotally adjustable inwards. This inward pivotal movement of the side wall 22 reduces the width of the holding space of the pen 12 such that the animal is securely retained between the walls 21 , 22 of the pen 12 , thereby being prevented from turning around within the pen 12 .
[0073] To facilitate pivotal movement of the side wall 22 , the upper end of the enclosed lower portion 23 is pivotally connected to the frame 20 of the pen 12 . This allows the lower end to pivot inwards towards the wall 21 . An anchor pin 19 is provided adjacent to the lower end of the enclosed lower portion 23 , which is spring loaded to be received in one of a plurality of holes 17 provided in the floor 18 of the pen 12 . While only one side wall of the pen 12 is shown as being inwardly pivotal and adjustable, it will be appreciated that either or both side walls may be adjustable to facilitate a wide variety of animal sizes and shapes.
[0074] While not shown in FIGS. 3 and 4 , the pen 12 comprises a plurality of load cells mounted in the roof 15 of the pen 12 , to weigh the animal as it stands upon the floor 18 of the pen 12 .
[0075] The animal is permitted into the pen 12 by moving the entry gates 24 from the closed position as shown in FIG. 3 to the open position as is shown in FIG. 4 . In the closed position, shown more clearly in FIG. 6A , the entry gates 24 substantially block the path of the animal, presenting a substantially solid wall to the animal. When the entry gates 24 are in the open position, they provide a straight open path for the animal to pass, substantially free of obstacles, which may cause the animal to baulk or become unsure of what lies ahead of them. Such an arrangement is important, particularly with respect to providing steady flow of cattle through the device 10 , as any obstruction may require operator intervention to force the animal against their will through the device 10 .
[0076] A similar arrangement is provided with the exit gates 26 . In this arrangement, when the animal progresses into the pen 12 and is presented on the floor 18 of the pen 12 for weighing by the load cells, the exit gates 26 are in the closed position as shown in FIG. 6B . In this position, the exit gates 26 extend across the animal's path, thereby presenting a solid obstacle to the animal. Following weighing of the animal, the exit gates 26 are moved to their open position, thereby providing a straight open path for the animal to pass, substantially free of obstacles, which may cause the animal to baulk or become unsure of what lies ahead of them.
[0077] The configuration of the gates 24 , 26 and the manner in which they move between open and closed positions provides additional assistance in progressing the animal into and out of the pen 12 . In the embodiment as shown in FIGS. 3 and 4 , the configuration of the entry gates 24 and the exit gates 26 is substantially the same. However, it will be appreciated that the entry gates 24 and the exit gates 26 could vary in construction and still fall within the spirit of the present invention.
[0078] Referring to FIGS. 5A and 5B , one embodiment of the entry gates 24 and exit gates 26 is shown. The gates 24 , 26 comprise a pair of opposing door members 30 , which are activated to open and close the ends of the pen 12 so as to permit entry of the animal into the holding space of the pen 12 , and exit of the animal from the pen 12 .
[0079] As shown more clearly in FIGS. 3 and 4 , each door member 30 has a height that extends substantially the height of the pen 12 . In this regard, for handling cattle, the height of the door may be between 1.9-2.2 meters to facilitate a variety of cattle types and sizes. The door member 30 comprises a planar surface or panel 32 , which is substantially flat and extends the length of the door member 30 . The panel 32 may be formed from a sheet of galvanized steel such that the lower portion of the panel 32 is fully enclosed. An opening 33 (as shown by cross hatches in FIG. 5A ) may be provided in the upper portion of the panel 32 , which opens into the holding space of the pen 12 . A guide member 31 is attached to the lower portion of the panel 32 and is angled to extend downward and away from the panel 32 . The guide member 31 is made from a sheet of galvanized steel, the purpose of which will be discussed in detail below.
[0080] The panel 32 extends between an upper pivot plate 34 and a lower pivot plate 35 . As shown in FIGS. 5C and 5D , the pivot plates 34 , 35 are substantially triangular in shape and are made from a sheet of galvanized steel, thereby enabling the panel 32 to be welded or otherwise attached between the plates 34 , 35 . In this regard, the panel 32 is attached to the plates 34 , 35 along a base edge 36 , which forms the base of the triangular plates 34 , 35 (see FIGS. 5C and 5D ). In this arrangement, the width of the panel 32 is such that it extends from one end of the base edge 36 of the plates 34 , 35 , but terminates before reaching the other end. This then results in a gap being formed between the end of the panel 32 and the end of the base edge 36 of the plates 34 , 35 .
[0081] A roller 38 is mounted in this gap to extend longitudinally between the pivot plates 34 , 35 . The roller 38 is made from steel and is mounted such that it is free to rotate between the plates 34 , 35 along its longitudinal axis. In this arrangement, the roller 38 is an extension of the panel 32 such that both the panel 32 and the roller 38 form a wall of the door member 30 . In this regard, when opposing door members 30 are in a closed position such that they are in abutting arrangement across the opening/exit of the pen 12 (as shown in FIGS. 6A and 6B ), the rollers 38 of each of the door members 30 are located adjacent to each other.
[0082] A pivot pin 37 extends from the outer surface of each of the pivot plates 34 , 35 to facilitate mounting of the door member 30 to the frame 20 of the pen 12 as shown in FIGS. 3 , 4 and 7 . In this arrangement, the door members 30 are mounted at either sides of the opening to the pen 12 , and rotate with respect to the pen 12 to open and close the ends of the pen 12 . As shown in FIGS. 5C and 5D , the pivot pin 37 is positioned opposite the base edge 36 of the plates 34 , 35 , namely in the angle joining the other two sides on the plates 34 , 35 . This arrangement allows the door member 30 to rotate about the pivot pin 37 under action of a pneumatic actuator, such that the door member can be moved between the opening and closing positions as will be discussed in more detail below. An actuator post 39 is also provided along an edge of the upper pivot plate 34 that extends between the roller 38 and the pivot pin 37 , to facilitate connection to a pneumatic actuator such that rotational movement can be imparted to the door member 30 .
[0083] FIG. 6A shows the door members 30 of the entry gates 24 in a closed position, as seen from the perspective of an animal awaiting entry into the pen 12 . As is shown, the door members 30 provide a barrier, which prevents an animal progressing further along the chute 11 into the pen 12 . The guide members 31 arranged at the lower portion of the panels 32 prevent the feet of the animal gripping the edge of the pen 12 , as they are angled to deflect the animal's feet away from the pen 12 . This arrangement prevents the animal awaiting entry in the pen 12 from stepping on the floor of the pen 12 which could have an adverse affect on the weight measurement being taken by the load cells of the pen 12 . Further, it ensures that the next animal entering the pen 12 is away from the entry gates 24 as they open, to assist the operator in controlling movement of the animals through the device.
[0084] As is shown, when the door members 30 are in the closed position, the rollers 38 are arranged adjacent to each other with a small gap provided therebetween. This gap may be around 40-50 mm in width, thereby preventing the tail of the animal being caught between the closing door members 30 . Pinching of the animal's tail between the door members 30 as they close may cause irritation to the animal.
[0085] FIG. 6B shows the door members 30 of the entry and exit gates 24 , 26 in the closed position as seen from within the pen 12 . In this arrangement, the panels 32 present a substantially flat surface to the animal, thereby enclosing the animal within the pen in a relatively safe and secure manner.
[0086] As alluded to above and shown in FIG. 7 , the opening and closing operation of the entry and exit gates 24 , 26 is controlled by the control system 5 , which in turn is controlled by an operator. The control system 5 communicates with a pneumatic actuator 40 to move a reciprocating piston 42 in a desired direction. As shown, the pneumatic actuator 40 is centrally mounted in the roof 15 of the pen 12 , such that the piston 42 is positioned substantially between the door members 30 at each end of the pen 12 . The piston 42 is attached at an end thereof to the actuator posts 39 extending from the upper pivot plates 34 of the door members 30 by linking arms 44 .
[0087] In order to open the pen 12 , the operator provides a signal whereby the control system causes the pneumatic actuator to move the piston 42 such that it is retracted within the actuator 40 , as shown with respect to entry gates 24 of FIG. 7 . In this position, the door members 30 of the entry gates 24 rotate to an open position, thereby permitting entry of the animal into the pen 12 . In the open position, the panel 32 of the door members 30 is arranged parallel to the direction of the movement of the animal, thereby providing a substantially open and unrestricted path for the animal to travel into the pen 12 . The panels 32 of the door members 30 are rotated out of the way of the progressing animal such that they are located substantially adjacent the side walls 21 , 22 of the pen 12 , so as not to substantially restrict the size of the opening of the pen 12 .
[0088] Upon receiving the animal in the pen 12 , the control system sends a signal to the pneumatic actuator 40 to move the piston 42 into an extended position whereby the piston is moved in the direction of arrow G, out of the actuator 40 . Movement of the piston 42 in this manner causes the linking arms 44 to pull against the actuator posts 39 so as to impart rotational motion to the pivot plates 34 , thereby rotating the door members 30 into the closed position as shown in FIGS. 6A and 6B . As the rollers 38 are arranged along the leading edge of the door members 30 , when the door members 30 are brought into the closed position, the rollers 38 ride across the rump of the animal as they close. Such an arrangement provides a positive force against the rear of the animal urging the animal into or out of the pen 12 . As the door members 30 roll across the rear of the animal, there is no significant pinching or squeezing of the animal that may cause discomfort resulting in the animal becoming agitated. Further, this action ensures that the door members 30 close around the animal, thereby substantially reducing the likelihood of more than one animal entering the pen 12 at any one time.
[0089] Following admittance of the animal into the pen 12 and closing the entry gates 24 , the animal is then weighed by the load cells, whereby the control system 5 sets the sorting device 14 to direct the animal to a desired holding region. The exit gates 26 are then opened by the control system 5 causing the pneumatic actuator 40 to retract the piston 42 in the direction of arrow H. This in turn causes the door members 30 to rotate into their open position, whereby the panel 32 is parallel to the direction of movement of the animal, which provides a clear passage for the animal to exit the pen 12 and enter the sorting device 14 to be delivered to the desired holding region.
[0090] Once the animal is clear of the pen 12 , the operator can then indicate to the control system 5 to open the entry gates 24 to allow the waiting animal to enter the pen 12 for weighing.
[0091] While operation of the entry and exit gates 24 , 26 has been described above as being pneumatically actuated, it will be appreciated that the gates 24 , 26 could also be manually actuated by an operator and still fall within the spirit of the present invention.
[0092] Further, it will be appreciated that while the above invention has been described as being controlled by a control system, such as an automated computerized control system, the present invention could be manually controlled as desired.
[0093] It will be appreciated that the present invention provides a system for handling livestock that enhances the natural progression of the animal through the entire system. The rotary action of the entry and exit gates of the system provides a simple means for directing and guiding the animal into an enclosed space, without the need for excessive human intervention. Such rotational action of the entry and exit gates prevents tilting/jamming of the gates, which is common with existing sliding/swinging gate systems and also ensures that the doors operate within a confined space that does not extend beyond the pen and into the area occupied by the operators. Such a rotational action of the gates also provides for quick actuation of the gates to ensure that individual animals are captured and released from the pen as desired, thereby greatly improving the handling ability of the device. Further, the ability to alter the holding space of the system allows a system that can safely cater for a variety of sizes of stock, reducing the possibility of injury to livestock and equipment.
[0094] It will be appreciated by persons skilled in the art that numerous variations and/or modifications may be made in the invention as shown in the specific embodiments without departing from the spirit or scope of the invention as broadly described. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive.
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A device ( 10 ) for receiving and confining an animal, such as a bail, is disclosed. The device ( 10 ) comprises a pen ( 12 ) having at least two elongate walls ( 21, 22 ) spaced apart to define a space into which the animal is received. An entry gate assembly ( 24 ) is located at a first end of the pen ( 12 ) and is movable between an open position, which permits entry of the animal into the pen ( 12 ), and a closed position. An exit gate assembly ( 26 ) is located at a second end of the pen ( 12 ) and movable between an open position, which permits the release of the animal from the pen ( 12 ), and a closed position, which prevents release of the animal from the receiving pen ( 12 ). At least one of the entry gate assembly ( 24 ) and the exit gate assembly ( 26 ) includes a pair of door members ( 30 ), each having a substantially vertically extending planar surface ( 32 ). Each door member ( 30 ) is rotatably mounted to the pen ( 12 ) at the first and/or second end of the pen such that when the gate assembly ( 24, 26 ) is moved to the closed position, the door members ( 30 ) rotate such that their planar surfaces ( 32 ) abut to extend substantially across the first and or second end of the pen ( 12 ), and when the gate assembly ( 24, 26 ) is moved to the open position, the door members ( 30 ) rotate such that their planar surfaces ( 32 ) are located adjacent a respective elongate wall ( 21, 22 ) of the pen ( 12 ).
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FIELD OF THE INVENTION
The present invention relates generally to blasthole drills which incorporate a sealing device or a sealing assembly to seal an opening around a drill pipe to prevent unwanted dust, debris and the like from undesirably escaping into the atmosphere.
BACKGROUND OF THE INVENTION
Blasthole drills are large earth drilling machines typically used in mining operations to drill holes for explosives. A conventional blast hole drill comprises a frame supported by crawlers for movement over the ground. A drill deck having a large rectangular opening is supported by the frame. A mast is supported by the frame for movement relative to the frame between a vertical position and a plurality of non-vertical positions. A drill pipe or drill string is supported relative to the mast, and a drill cutter bit is connected to a lower end of the drill pipe. The drill pipe extends through the opening of the drill deck and the shape of the opening allows the drill pipe to be positioned at the desired angle relative to the drill deck for drilling purposes. A rotary head engages an upper end of the drill pipe and moves along the mast. The rotary head rotates the drill pipe, and thus the drill cutter bit, into the ground.
During operation, when a drill cutter bit is caused to rotate and move downward into the ground, the drilled earthen material, such as dust, rock chips, rubble, and the like, travels up alongside the drill pipe and out of the drilled hole such that the drilled material is thereafter collected in a curtained-off area between the blasthole drill and the ground. In an effort to prevent escape of the earth cutting dust and the like into the surrounding environment, it is known to seal the opening of the drill deck and, in particular, to seal the opening around the drill pipe relative to the drill deck.
Known mechanisms designed to seal a substantial portion of the opening of a drill deck include a plurality of overlapping, typically square or rectangular, rigid metal plates which are adjustably secured to a track on the drill deck. The metal plates are positioned one above another so as to define overlapped portions between adjacent metal plates whereby the overlapped portions are generally perpendicular to the plane in which the drill pipe moves. As is generally known, the location of the metal plates with respect to each other depends on the angle of the drill pipe relative to the drill deck as the drill pipe extends through the opening of the drill deck. For example, if the drill pipe is in a vertical position, all of the metal plates are typically located to one side of the drill pipe. On the other hand, if the drill pipe is in a non-vertical position, one or more of the metal plates are typically located on one side of the drill pipe and one or more of the metal plates are typically located on an opposite side of the drill pipe. Although these metal plates are known to substantially seal the majority of the opening of the drill deck, the metal plates are not typically designed to independently seal the opening directly around the drill pipe. Thus, it is generally known to provide a dust cone and a dust cone carrier to be used in cooperation with the metal plates so as to seal the opening around the drill pipe. The dust cone carrier is typically also a metal plate which is adjustably secured to a track of the drill deck in much the same fashion as the metal plates. The dust cone carrier generally includes an elliptical hole through which the drill pipe can extend. The elliptical hole allows the drill pipe to pass through the dust cone carrier in any operable angular position relative to the drill deck. A dust cone of known material is secured to the dust cone carrier and extends below the dust cone carrier into the curtained-off area between the blasthole drill and the ground. The dust cone is generally configured such that the larger diameter hole of the dust cone is positioned near or adjacent the bottom side of the dust cone carrier, and the smaller diameter hole of the dust cone is positioned near, or in actual contact with, the drill pipe. In some known mechanisms, one or more plastic or rubber-like sheets having circular holes therethrough may be located internal to the dust cone in order to surround and possibly come into contact with the drill pipe.
In such known mechanisms, as the drilled material travels up alongside the drill pipe and out of the drilled hole, the shape and location of the dust cone is designed to prevent the drilled material from continuing on up alongside the drill pipe and also cause the drilled material to fall into the curtained-off area between the blasthole drill and the ground. The plastic or rubber-like sheets, if utilized, are intended to prevent any drilled material which happens to pass between the small diameter hole of the dust cone and the outer surface of the drill pipe from continuing farther up alongside the drill pipe. As a result, in conjunction with the metal plates, dust and the like is prevented from escaping into the atmosphere through the opening in the drill deck of a blasthole drill.
There are other known mechanisms for sealing an opening around a structure, but such mechanisms are generally not suitable for use in typical blasthole drill equipment for reasons commonly known to those skilled in the art.
SUMMARY OF THE INVENTION
Blasthole drills are frequently required to drill holes at angles other than vertical, typically, at angles up to 30 degrees or more off of vertical. As previously explained, known blasthole drills allow a drill pipe to pass through the opening of a drill deck at the desired angle. Nonetheless, problems do occur with the mentioned known sealing mechanisms when it is desired to change the drilling angle of the drill pipe relative to the drill deck.
One problem is attributable to the necessary manual handling of the metal plates to seal that portion of the opening of a drill deck not immediately surrounding the drill pipe. When the blasthole drill pipe is in a vertical position, the dust cone carrier is usually located all the way to one end of the drill deck and the metal plates are all located to the same side of the dust cone carrier in an overlapping manner as previously described. However, when the drill pipe is positioned off of vertical, its location, and thus the location of the dust cone carrier, relative to the drill deck moves. Therefore, when the drill pipe is positioned in a non-vertical position, in order to close that portion of the opening not immediately surrounding the drill pipe, some of the metal plates will be positioned to one side of the dust cone carrier and some of the metal plates will be positioned on an opposite side of the dust cone carrier. To properly position the metal plates, the metal plates are manually handled by one or more individuals, depending on the size of the metal plates, and manipulated into place with respect to the drill deck and dust cone carrier. This process has proven to be a somewhat cumbersome and time-consuming operation.
Another problem is attributable to passing the drill pipe through or removing the drill pipe from the opening of the drill deck so that the desired drilling angle can be set. Because of the manner in which the metal plates function, the drill pipe must be removed from the drill deck opening everytime a change in the drilling angle is required. As known, the drill cutter bit extends farther radially outward with respect to a drill hole axis extending through the drill pipe than the outer surface of the drill pipe so that the drilled material is able to travel up alongside the drill pipe and out of the drilled hole during operation of the blasthole drill. Thus, when the drill pipe is passed through or retracted from the opening of the drill deck, the sharp edges of the drill cutter bit are known to rip or otherwise damage the dust cone near the small diameter hole of the dust cone. Moreover, if utilized, the plastic or rubber-like sheets located internal to the dust cone may also be damaged by the drill cutter bit as a result of their close relationship with the outer surface of the drill pipe. As can be appreciated, such damage to the dust cone and/or plastic or rubber-like sheets can adversely affect the sealing of the opening around the drill pipe. Further, damage to the dust cone and/or plastic or rubber-like sheets may require frequent replacement thereof which adds unnecessary expense and downtime to the overall operation of the blasthole drill. Alternatively, it is possible for the dust cone and plastic or rubber-like sheets to be installed after or removed before the drill pipe is passed through or is retracted from the opening in the drill deck, but such operations are unduly burdensome and excessively inefficient.
Accordingly, the present invention provides a blasthole drill which alleviates these problems and many other problems known to those skilled in the art. The present invention provides a blasthole drill which allows the drilling angle of the drill pipe to be changed while the drill pipe is extending through the opening of the drill deck. The present invention also provides a blasthole drill which allows for variable positioning of the drill pipe with respect to the drill deck and which allows the drill pipe to be moved relative thereto without having to manually handle or manipulate any sealing components which are designed for sealing the opening of the drill deck and/or sealing the opening around the drill pipe. The present invention provides a blasthole drill incorporating a new apparatus to seal the opening in a drill deck, and in particular the opening around the drill pipe, in order to minimize passage of drilled material through the opening and into the atmosphere.
In particular, the present invention provides a sealing assembly which includes a pliable membrane of suitable material which is connected to the drill deck and which surrounds the drill pipe to substantially seal the opening around the drill pipe when the drill pipe extends through the opening. More particularly, the pliable membrane comprises a plurality of overlapping sheets. Even more particularly, the pliable membrane comprises flexible seal flaps which are connected to a drill deck such that a first seal flap at least partially overlaps and engages a second seal flap. The seal flaps are separable to engage opposite sides of a drill pipe when the drill pipe passes through an opening of the drill deck. The seal flaps substantially seal the opening around the drill pipe when the drill pipe extends through the opening in order to minimize passage of drilled material through the opening.
Preferably, there is provided at least one set of flexible seal flaps connected to the drill deck. Each seal flap includes a free edge. A first set of seal flaps is arranged relative to the drill deck such that one seal flap partially overlaps and lays upon another seal flap, wherein the free edges of the respective seal flaps are located on opposite sides of a plane traveled by the drill hole axis of the drill pipe upon movement of the mast. The seal flaps are separable so that the free edges of the seal flaps can engage opposite sides of the drill pipe when the drill pipe extends through the opening in order to substantially seal the opening around the drill pipe in each operable position of the drill pipe.
To increase the effectiveness of sealing the opening around the drill pipe, one or more additional sets of flexible seal flaps which are substantially similar to the first set of seal flaps can be located below the first set of seal flaps.
To further increase the effectiveness of sealing the opening around the drill pipe, at least one set of flexible end seal flaps cooperates with the other seal flaps to further surround the drill pipe when the drill pipe is near an end wall of the drill deck.
A feature of the present invention is to provide a blasthole drill which does not require the use of conventional dust cone carriers, dust cones and adjustable metal plates which inhibit drilled earthen material from passing into the atmosphere.
Another feature of the present invention is to provide a blasthole drill which incorporates an apparatus which seals the opening around a drill pipe and which is not damaged by a drill cutter bit when it is desired to change the drilling angle of the drill pipe.
A further feature of the present invention is to provide a blasthole drill which allows for the adjustment of the drilling angle of a drill pipe without having to remove the drill pipe from the opening of the drill deck when it is desired to change the drilling angle of the drill pipe.
Yet another feature of the present invention is to provide a blasthole drill which allows for adjustment of the drilling angle of a drill pipe without having to disassemble any part of the sealing apparatus designed to seal the opening around the drill pipe.
Still another feature of the present invention is to provide a blasthole drill having a sealing assembly which effectively seals the opening around a drill pipe and which is more economical to manufacture and use than what has hitherto been provided.
Other features and advantages of the invention will become apparent to those skilled in the art upon review of the following detailed description, claims and drawings in which like numerals are used to designate like features.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevational view of a blasthole drill in which the present invention is employed.
FIG. 2 is an enlarged partial perspective view of a drill deck of the blasthole drill illustrating an apparatus according to the present invention which seals the opening around a drill pipe, wherein the drill pipe is shown in a vertical (solid lines) position and a non-vertical (dashed lines) position.
FIG. 3 is an enlarged portion of FIG. 2 .
FIG. 4 is a cross-sectional view taken along line IV—IV of FIG. 5 .
FIG. 5 is a partial top view of FIG. 2 wherein the drill pipe is shown in an angled or non-vertical position.
FIG. 6 is a cross-sectional view taken along line VI—VI of FIG. 5 .
Before the 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 construction and 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 or being carried out in various ways. Also, it is understood that the phraseology and terminology used herein are for the purpose of description and should not be regarded as limiting. The use of “including” and “comprising” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items and equivalents thereof. The use of “consisting of” and variations thereof herein is meant to encompass only the items listed thereafter and the equivalents thereof.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Illustrated in FIG. 1 is a blasthole drill 10 in which the present invention is employed, it being understood that a drill pipe seal according to the present invention is capable of use in other blasthole drills and in other constructions where an opening around a structure requires sealing. The blasthole 10 comprises a frame 14 supported by crawlers 18 for movement over the ground. A mast 22 is supported by the frame 14 for movement relative thereto about a generally horizontal axis 26 between a substantially vertical position (as shown) and a number of angled or non-vertical positions. The mast 22 defines a drill hole axis 30 which moves in a plane 32 (see FIGS. 4 and 5) as the mast 22 moves relative to the frame 14 . A rotary head 34 is movable relative to the mast 22 along the drill hole axis 30 . The rotary head 34 is selectively engageable with an upper end of a drill pipe 38 which is supported relative to the mast 22 . The frame 14 , crawlers 18 , mast 22 , rotary head 34 and drill pipe 38 can be of conventional construction and do not require a detailed description. Known blasthole drills are described, for example, in U.S. Pat. Nos. 5,622,232 and 5,653,297 both to Whisenhunt, which are hereby incorporated herein by reference.
Referring to FIG. 2, the blasthole drill 10 includes a drill deck 42 . The drill deck 42 is supported by the frame 14 of the blasthole drill 10 illustrated in FIG. 1 . The drill deck 42 is generally made of metal but can be made of other materials depending on the circumstances. The drill deck 42 includes a front wall 46 , a back wall 50 , and opposing side walls 54 and 58 . The drill deck 42 is preferably rectangular in shape but may be of any number of different shapes. The drill deck 42 includes an opening 62 (see FIG. 4) which is generally defined by the walls 46 , 50 , 54 and 58 . The drill deck 42 can be supported by the frame 14 in any number of conventional ways, but attaching the walls 46 , 50 , 54 and 58 of the drill deck 42 to the frame 14 with bolts 66 (see FIG. 4) or any other equivalent fastening means is generally acceptable.
As illustrated in FIG. 2, seal assembly 70 is connected to the drill deck 42 which effectively substantially closes the opening 62 of the drill deck 42 . The drill pipe 38 extends through the opening 62 and is surrounded by the seal assembly 70 . As previously explained, it is desirable to substantially seal the opening 62 , especially around the drill pipe 38 , so as to inhibit the escape of earth-cutting material and the like into the environment.
With continued reference to FIG. 2, the seal assembly 70 includes a first set of flexible seal flaps comprising a first flexible seal flap 74 and a second flexible seal flap 78 . The flexible seal flaps 74 and 78 may be of any material suitable for use according to the principles of the present invention, but an industrial rubber-like material would be particularly well-suited for use. The seal flaps 74 and 78 are preferably rectangular in shape but may be of other shapes consistent with the principles of the present invention. As further explained below, the seal flaps 74 and 78 extend substantially the entire distance between the walls 46 and 50 adjacent the walls 54 and 58 , respectively. The seal flap 74 includes a free edge 82 (see also FIG. 4 ), an opposite back edge 86 (see FIG. 4 ), opposite side edges 90 and 94 , a top side 98 and a bottom side 102 (see FIG. 4 ). The seal flap 78 includes a free edge 106 (see also FIG. 4 ), an opposite back edge 110 (see FIG. 4 ), opposite side edges 114 and 118 , a top side 122 and a bottom side 126 (see FIG. 4 ).
FIG. 4 best illustrates a preferred maimer of connecting the seal flaps 74 and 78 to the drill deck 42 . As shown, drill deck 42 includes a first flange 130 extending from the side wall 54 into the opening 62 , and a second flange 134 extending from the side wall 58 into the opening 62 . The flanges 130 and 134 may be formed as a part of the walls 54 and 58 , respectively, or the flanges 130 and 134 may be attached to the walls 54 and 58 , respectively, in any number of ways known to those skilled in the art, such as by welding. Preferably, the flanges 130 and 134 are of at least the same length as the seal flaps 74 and 78 in order to properly support the respective seal flaps 74 and 78 as further explained below. The flanges 130 and 134 extend into the opening 62 in a way that will not prevent the drill pipe 38 from extending through the opening 62 , nor will the flanges 130 and 134 prevent the desired movement of the drill pipe 38 .
Referring still to FIG. 4, the seal flap 74 is positioned over flange 130 such that a portion of the bottom side 102 of seal flap 74 rests on top of the flange 130 for support. Edge 86 of the seal flap 74 preferably abuts against an inside surface of the side wall 54 . A retaining strip 142 (see also FIG. 2 ), preferably made of metal, is placed over and into contact with a portion of the top side 98 of the seal flap 74 at or near the inside surface of the side wall 54 . Multiple retaining strips 142 may be used as needed as is shown in FIG. 2. A plurality of bolts 146 (see also FIG. 2) extend through the retaining strip 142 , the seal flap 74 and the flange 130 . Nuts 150 are threaded onto the bolts 146 to secure the seal flap 74 to the drill deck 42 .
The seal flap 78 is connected to the drill deck 42 in the same manner as the seal flap 74 is connected to the drill deck 42 such that further description is not necessary. It should be noted that the seal flaps 74 and 78 can be connected to the drill deck 42 in any number of different ways, such as with adhesive, and still provide the features according to the principles of the present invention.
With reference to FIGS. 2 and 4, the position of the first seal flap 74 with respect to the position of the second seal flap 78 in relation to the drill deck 42 and drill pipe 38 will now be described. As can be observed, a portion of the seal flap 74 overlaps and engages a portion of the seal flap 78 . FIG. 4 best illustrates, in dashed lines, the overlapping portions of the seal flaps 74 and 78 . The bottom side 102 of the seal flap 74 partially overlaps and engages the top side 122 of the seal flap 78 . The free edge 82 of the seal flap 74 is located on one side of the plane 32 and the free edge 106 of the seal flap 78 is located on the opposite side of the plane 32 . As also shown in FIG. 4, the flanges 130 and 134 do not extend as far inward with respect to walls 54 and 58 as do seal flaps 74 and 78 . The flanges 130 and 134 are intended to provide support for the flexible seals 74 and 78 but are not intended to prevent the flaps 74 and 78 from flexing when contact is made with the drill pipe 38 as will be further explained below. Although the seal flaps 74 and 78 are shown as bending in an upwards direction with respect to the flanges 130 and 134 , it is envisioned that the seal flaps 74 and 78 can bend in a downward direction and still function according to the principles of the present invention.
FIGS. 2 and 4 illustrate how the sealing assembly 70 substantially seals the opening 62 and, in particular, the portion of the opening 62 around the drill pipe 38 . The overlapping and engaging action of the seal flaps 74 and 78 effectively closes a majority of the opening 62 except for where the drill pipe 38 extends therethrough. In this location, the seal flaps 74 and 78 separate when the drill pipe 38 is passed through the opening 62 such that the free edges 82 and 106 of the respective seal flaps 74 and 78 engage opposite sides of the drill pipe 38 . As a result, the opening 62 around the drill pipe 38 is substantially sealed. As the drill pipe 38 moves, the seal flaps 74 and 78 separate as needed to engage the opposite sides of the drill pipe 38 and, because of their flexible nature, overlap and engage each other as shown to close that portion of the opening 62 where the drill pipe 38 was previously located (see, e.g., FIG. 2 as compared to FIG. 5 ).
FIG. 5 shows the drill pipe 38 in a non-vertical position. As can be observed, the flexible nature of the seal flaps 74 and 78 enables the drill pipe 38 to be located in a non-vertical operating position while the seal flaps 74 and 78 still substantially seal the opening 62 around the drill pipe 38 . Thus, the seal flaps 74 and 78 are capable of sealing the opening around the drill pipe 38 in each operating position of the drill pipe 38 .
As shown in FIGS. 2-3 and 5 - 6 , the seal assembly 70 includes flexible end seal flaps 154 and 158 . Since the flaps 154 and 158 are virtually identical, reference to one can be viewed as reference to the other. The seal flaps 154 and 158 are preferably made of the same material as seal flaps 74 and 78 . The seal flaps 154 and 158 are located at or near the walls 46 and 50 , respectively. The seal flaps 154 and 158 each include a free edge 170 , an opposite back edge 174 , opposing side edges 178 , a top side 182 and a bottom side 186 . Each seal flap 154 and 158 includes spaced slits 190 and 194 which extend somewhat from the free edges 170 towards the opposite back edges 174 and which extend completely through each seal flap 154 and 158 from the top sides 182 through the bottom sides 186 , thereby creating portions 198 of each seal flap 154 and 158 which are independently bendable with respect to the other portions of the respective seal flaps 154 and 158 upon contact with the drill pipe 38 so as to engage a portion of the drill pipe 38 to further seal the opening 62 around the drill pipe 38 . The seal flaps 154 and 158 are preferably rectangular in shape and are connected to respective walls 46 and 50 of the drill deck 42 through use of flanges 202 , retaining strips 142 , bolts 146 and nuts 150 (see FIG. 6) in much the same way as seal flaps 74 and 78 are connected to the drill deck 42 . With particular reference to FIGS. 2 and 3, it can be observed that the first and second seal flaps 74 and 78 partially overlap and engage the seal flaps 154 and 158 . The respective bottom sides 102 and 126 of the seal flaps 74 and 78 , mate against the respective top sides 182 of the seal flaps 154 and 158 . As shown, when drill pipe 38 extends through the opening 62 in close proximity to the wall 50 of the drill deck 42 so as to contact a portion of the free edge 170 of the seal flap 154 , the bendable portion 198 independently moves with respect to the other portions of the seal flap 154 so as to properly engage the drill pipe 38 to further seal the opening 62 around the drill pipe 38 . Conversely, as shown in FIG. 5, if the drill pipe 38 is positioned so as not to come into contact with seal flap 154 , the seal flaps 74 and 78 overlap the end seal flap 154 such that the bendable portion 198 is beneath the seal flaps 74 and 78 .
The seal assembly 70 may also include second and third sets of flexible seal flaps 206 , which are substantially identical to the seal flaps 74 and 78 , beneath the seal flaps 74 and 78 . Preferably, each set of seal flaps 206 cooperates with a pair of end seal flaps 210 , which are substantially identical to seal flaps 154 and 158 . The purpose of the additional flexible flaps is to increase the effectiveness of the sealing assembly 70 , it being understood that more or fewer flaps can be used in accordance with the principles of the present invention.
Variations and modifications commensurate with the above teachings in skill or knowledge of the relevant art, are within the scope of the present invention. For example, the pliable membrane may be of any suitable material which allows a drill pipe to pass therethrough and which is also elastic enough to close back upon itself when the drilling angle of the drill pipe is adjusted and the position of the drill pipe relative to the drive deck changes. The embodiments described herein are intended to explain the best modes known for practicing the invention and to enable others skilled in the art to utilize the invention as such, or other embodiments and with various modifications required by the particular applications or uses of the present invention. It is intended that the appended claims are to be construed to include alternative embodiments to the extent permitted by the prior art.
Various features of the invention are set forth in the following claims.
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A blasthole drill includes a drill pipe seal to seal an opening around a drill pipe which extends through a drill deck in order to substantially prevent drilled ground material, such as dust and rock chips, from escaping into the atmosphere. The seal comprises a pliable membrane which is capable of sealing the opening around the drill pipe and which also allows the drill pipe to be positioned in variable drilling positions while still providing the necessary sealing arrangement. First and second flexible seal flaps are connected to the drill deck in an overlapping fashion. The seal flaps are separable to allow the drill pipe to pass therethrough, but otherwise remain overlapped. The flexible seal flaps substantially seal the opening around the drill pipe in any operable position of the drill pipe. To increase the sealing effectiveness, additional pairs of similar seal flaps may be added. The drill pipe seal allows the drill angle of the drill pipe to be changed without having to remove the drill pipe from the drill deck.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to and the benefit of Korean Patent Application No. 10-2006-0120815 filed in the Korean Intellectual Property Office on Dec. 1, 2006, and 10-2007-0010954 filed in the Korean Intellectual Property Office on Feb. 2, 2007, the entire contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] (a) Field of the Invention
[0003] The present invention relates to a call connection control method of a base station, and more particularly, to a call connection control method using a state function matrix.
[0004] (b) Description of the Related Art
[0005] A portable Internet system among communication systems is a 3.5 generation mobile communication system using a wireless transmission method that guarantees spectrum usage efficiency in a 2.3 GHz frequency bandwidth so as to provide various types of Internet protocol (IP)-based services (e.g., streaming video, file transfer protocol (FTP), e-mail, and chatting) provided in a wired Internet and to transmit data packet at a high speed. The portable Internet system transmits and receives data for each frame to support high speed data packet transmission in a wireless link, and uses orthogonal frequency division multiplexing (OFDM), frequency division multiple access (FDMA), and time division duplexing (TDD) wireless transmission methods.
[0006] Generally, in most of the communication systems including the portable Internet system, when a terminal performs call connection, a base station uses logic structure including an if-then-else or a case command statement to determine a current call state and a received message, and performs a state function required according to a determination result. However, the base station using the logic structure usually performs a determination process of “a number of entire states/2+a number of entire received messages/2”, which causes waste of central processing unit (CPU) resources and deteriorates system performance.
[0007] The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.
SUMMARY OF THE INVENTION
[0008] The present invention has been made in an effort to provide a call connection control method for improving call connection control performance.
[0009] According to an exemplary embodiment of the present invention, in a call connection control method of a base station, a message is received, a state function corresponding to the received message and a current call state is called among a plurality of state functions that are mapped to a plurality of elements of a state function matrix, and the called state function is operated.
[0010] Here, the state function matrix includes a plurality of call states as one index among row and column indexes, and a plurality of messages as the other index.
[0011] According to another exemplary embodiment of the present invention, in a method of making state function matrix used for call connection control of a base station, a plurality of call states are established as one index among row and column indexes of a state function matrix, a plurality of messages are established as the other index, and an element of the state function matrix corresponding to a call state among the plurality of call states and a message among the plurality of messages is established to be a state function operated when receiving the message among the plurality of messages in the call state among the plurality of call states.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is a schematic diagram of a communication system according to an exemplary embodiment of the present invention.
[0013] FIG. 2 is a flowchart representing a call connection control method according to the exemplary embodiment of the present invention.
[0014] FIG. 3 is a diagram representing a state function matrix used in the call connection control method according to the exemplary embodiment of the present invention.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0015] In the following detailed description, only certain exemplary embodiments of the present invention have been shown and described, simply by way of illustration. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. Accordingly, the drawings and description are to be regarded as illustrative in nature and not restrictive. Like reference numerals designate like elements throughout the specification.
[0016] In addition, unless explicitly described to the contrary, the word “comprise”, and variations such as “comprises” and “comprising”, will be understood to imply the inclusion of stated elements but not the exclusion of any other elements.
[0017] A method for controlling call connection of a communication system according to an exemplary embodiment of the present invention will be described with reference to the figures.
[0018] FIG. 1 is a schematic diagram of a communication system according to the exemplary embodiment of the present invention. In the exemplary embodiment of the present invention, a portable Internet system based on an IEEE 802.16 wireless metropolitan area network (MAN) will be exemplified, but it is not limited thereto, and another communication system may be applied.
[0019] As shown in FIG. 1 , the communication system according to the exemplary embodiment of the present invention includes an access terminal (AT) 110 , an access point (AP) 120 , a packet access router (PAR) 130 , and a network 140 .
[0020] The AP 120 controls an access of the AT 110 , performs a packet match operation between a wired link and a wireless link, performs a wireless transmitting/receiving control operation, and manages wireless bands. In addition, the AP 120 includes a radio frequency subsystem (RFS) 121 , an access point traffic subsystem (ATS) 122 , an access point control subsystem (ACS) 123 , and an ethernet switch 124 . The AP 120 functions as a base station of the communication system.
[0021] The RFS 121 transmits and receives data in the wireless link. The ATS 122 processes traffic, performs packet scheduling, controls the wireless link, manages radio resources, performs packet match between the wired link and the wireless link, and performs a hybrid automatic repeat request (HARQ) control operation. That is, the ATS 122 receives cell information and user connection information from the ACS 123 to process the traffic and perform the packet scheduling, and transmits a scheduled downlink data combination to the RFS 121 to request wireless link transmission or processes a received uplink data combination to transmit it to the PAR 130 . The ACS 123 controls protocol operations for controlling the AP 120 and the AT 110 , and controls connection of call from the AT 110 .
[0022] The PAR 130 accesses the AP 120 and the network 140 , and controls authentication, dynamic host configuration protocol (DHCP), mobile Internet protocol (MIP), handover between ATs, and handover between PARs. The network 140 may be an Internet protocol (IP)-based wired core network.
[0023] The method for controlling call connection in the AP 120 according to the exemplary embodiment of the present invention will now be described with reference to FIG. 2 and FIG. 3 .
[0024] FIG. 2 is a flowchart representing a call connection control method according to the exemplary embodiment of the present invention.
[0025] Firstly, call states varying in a call connection process according to the exemplary embodiment of the present invention will be described.
[0026] As shown in FIG. 2 , there are seven call states from S 1 to S 7 in a call connection process from an initial ranging state and a terminal registration state.
[0027] A state S 1 is an idle state in which the ACS 123 waits to receive a ranging request message (RNG-REQ) from the AT 110 . In a state S 2 , the ACS 123 waits to receive a ranging complete message (RNG-Complete) from the ATS 122 . In a state S 3 , a ranging process is finished, and the ACS 123 waits to receive a subscriber station basic capability request message (SBC-REQ) from the AT 110 . In a state S 4 , the ACS 123 waits to receive a subscriber station basic capability complete message (SBC-Complete) from the ATS 122 . In a state S 5 , the subscriber station basic capability request message (SBC-REQ) and the subscriber station basic capability complete message (SBC-Complete) have been received, and the ACS 123 waits to receive a registration request message (REG-REQ) from AT 110 . In a state S 6 , the ACS 123 waits to receive a registration complete message (REG-Complete) from the ATS 122 . In a state S 7 , the ACS 123 waits to receive a registration response message (REGrsp) from the PAR 130 .
[0028] A method for controlling call connection in the AP 120 shown in FIG. 1 and a method for varying a call state according to the controlling call connection will now be described.
[0029] In the state S 1 , when the ACS 123 receives the RNG-REQ message for requesting initial ranging from the AT 110 through the ATS 122 in steps 201 and 202 , the ACS 123 calls a function fnRNG-REQ. When the function fnRNG-REQ is operated, the ACS 123 transmits a ranging command message (RNG-Command) for requesting initial setting of ranging information to the ATS 122 in step 203 , a call state is changed to the state S 2 for waiting for an RNG-Complete message from the ATS 122 in step 231 , and a first sensing timer of the state S 2 is operated. The ACS 123 measures a time by the first sensing timer after a call state is changed to the state S 2 , and performs a function fnS 2 TimerExpirey when the ACS 123 does not receive a RNG-Complete message before a predetermined time of the first sensing timer expires.
[0030] The ATS 122 finishes the initial setting of the ranging information, and transmits the RNG-Complete message to the ACS 123 . In the state S 2 , when receiving the RNG-Complete message from the ATS 122 in step 204 , the ACS 123 calls a function fnRNG-Complete. When the function fnRNG-Complete is operated, the ACS 123 forms a ranging response message (RNG-RSP) to transmit it to the AT 110 in steps 205 and 206 , a call state is changed to the state S 3 for waiting for the SBC-REQ message from the AT 110 in step 232 , and a second sensing timer of the state S 3 is operated. The ACS 123 measures a time by the second sensing timer after the call state is changed, and performs a function fnS 3 TimerExpirey when the ACS 123 does not receive the SBC-REQ message before a predetermined time of the second sensing timer expires.
[0031] In the state S 3 , when receiving the SBC-REQ message from the AT 110 through the ATS 122 in steps 207 and 208 , the ACS 123 calls a function fnSBC-REQ. When the function fnSBC-REQ is operated, the ACS 123 transmits a subscriber station basic capability command message (SBC-Command) for requesting setting of subscriber station basic capability information to the ATS 122 in step 209 , a call state is changed to the state S 4 for waiting for the SBC-Complete message from the ATS 122 in step 233 , and a third sensing timer of the state S 4 is operated. The ACS 123 measures a time by the third sending timer after the call state is changed to the sensing timer, and performs a function fnS 4 TimerExpirey when the ACS 123 does not receive the SBC-Complete message before a predetermined time of the third sensing timer expires.
[0032] The ATS 122 finishes the setting of the subscriber station basic capability information, and transmits the SBC-Complete message to the ACS 123 . In the state S 4 , when receiving the SBC-Complete message from the ATS 122 in step 210 , the ACS 123 calls a function fnSBC-Complete. When the function fnSBC-Complete is operated, the ACS 123 forms a subscriber station basic capability response message (SBC-RSP) for confirming the setting of the subscriber station basic capability information to transmit it to the AT 110 in steps 211 and 212 , a call state is changed to the state S 5 for waiting for the REG-REQ message from the AT 110 in step 234 , and a fourth sensing timer of the state S 5 is operated. The ACS 123 measures a time after a state is changed to S 5 by the fourth sensing timer, and performs a function fnS 5 TimerExpirey when the ACS 123 does not receive the REG-REQ message before a predetermined time of the fourth sensing timer expires.
[0033] In the state S 5 , when receiving the REG-REQ message from the AT 110 through the ATS 122 in steps 213 and 214 , the ACS 123 calls a function fnREG-REQ. When the function fnREG-REQ is operated, the ACS 123 transmits a registration command message (REG-Command) for requesting setting of terminal registration to the ATS 122 in step 215 , a call state is changed to the state S 6 for waiting for the REG-Complete message from the ATS 122 , and a fifth sensing timer of the state S 6 is operated. The ACS 123 measures a time after the state is changed to S 6 by the fifth sensing timer, and a function fnS 6 TimerExpirey is operated when the ACS 123 does not receive the REG-Complete message before a predetermined time of the fifth sensing timer expires.
[0034] The ATS 122 finishes the setting of the terminal registration, and transmits the REG-Complete message to the ACS 123 . In the state S 6 , when receiving the REG-Complete message from the ATS 122 in step 216 , the ACS 123 calls a function fnREG-Complete. When the function fnREG-Complete is operated, the ACS 123 forms a registration request message (REGreq) for requesting the setting of the terminal registration to transmit it to the PAR 130 in step 217 , a call state is changed to the state S 7 for waiting for the REGrsp message from the PAR 130 in step 236 , and a sixth sensing timer of the state S 7 is operated. The ACS 123 measures a time after the state is changed to S 7 by the sixth sensing timer, and performs a function fnS 7 TimerExpirey when the ACS 123 does not receive the REGrsp message before a predetermined time of the sixth sensing timer expires.
[0035] In the state S 7 , when receiving the REGrsp message from the PAR 130 in step 218 , the ACS 123 calls a function fnREGrsp. When the function fnREGrsp is operated, the ACS 123 forms a registration response message (REG-RSP) for determining registration of the subscriber station to transmit it to the AT 110 in steps 219 and 220 , transmits a dynamic service addition request message (DSAreq) to the PAR 130 to start management connection setting for Internet protocol (IP) allocation in step 221 , and the call state is changed to a state for waiting for a response thereof.
[0036] As described, when receiving a message, the ACS 123 of the AP 120 calls a state function corresponding to a current call state and the received message, and operates the state function. In this case, if the ACS 123 uses logic structures including if-then-else and case sentences to sequentially check the current call state and the received message and to find the corresponding state function, a number “the number of all states/2+the number of all received messages/2” of checking processes is performed, and therefore resources are wasted. A method for finding a state function corresponding to a current call state and a received message without resource waste will be described with reference to FIG. 3 .
[0037] FIG. 3 is a diagram representing a state function matrix used in the call connection control method according to the exemplary embodiment of the present invention.
[0038] As shown in FIG. 3 , in the state function matrix for the call connection control, rows are call states in the call connection process and columns are messages that may be received by the ACS 123 . Accordingly, according to the exemplary embodiment of the present invention, as shown in FIG. 3 , the state function matrix includes 7 rows from the state S 1 to the state S 7 and n columns from the RNG-REQ to a Time-Expiry message. The Time-Expiry message is used when a desired message is not received before a predetermined time expires in a current call state. Differing from FIG. 3 , it may be established that columns are the call states and rows are the messages.
[0039] An element corresponding to an i th row and a j th column in the state function matrix is a state function operated when the ACS 123 receives a message j in a state i.
[0040] When receiving the message j in the state i, the ACS 123 operates a state function determined in an i th row and a j th column in the state function matrix, and performs a corresponding process for the call connection. That is, the ACS 123 may directly find a state function that is an element corresponding to a column j corresponding to a received message and a row i corresponding to a current call state from the state function matrix.
[0041] The state functions include state functions operated when receiving a normal message in the current call state, and state functions operated when receiving an abnormal message in the current call state. In the state functions operated when receiving the normal message in the current call state, received message validity check, resource management, transmission message configuration, state change, and sensing timer operation of the changed call state are performed. The state functions operated when receiving the normal message includes fnRNG-REQ, fnRNG-Complete, fnSBC-REQ, fnSBC-Complete, fnREG-REQ, fnREG-Complete, and fnREGrsp functions.
[0042] The fnRNG-REQ function is operated when the ACS 123 receives the RNG-REQ message in the state S 1 , the fnRNG-Complete function is operated when the ACS 123 receives the RNG-Complete message 203 shown in FIG. 2 in the state S 2 , the fnSBC-REQ function is operated when the ACS 123 receives the SBC-REQ message in the state S 3 , the fnSBC-Complete function is operated when the ACS 123 receives the SBC-Complete message in the state S 4 , the fnREG-REQ function is operated when the ACS 123 receives the REG-REQ message in the state S 5 , the fnREG-Complete function is operated when the ACS 123 receives the REG-Complete message in the state S 6 , and the fnREGrsp function is operated when the ACS 123 receives the REGrsp message in the state S 7 .
[0043] The state functions operated when receiving the abnormal message includes fnUnexpectedMsg and fnSiTimerExpiry functions.
[0044] The fnUnexpectedMsg function is operated when receiving a message that is not expected in the current call state, and the fnSiTimerExpiry function is operated when an expected message is not received before a predetermined time expires in the state i.
[0045] The above-described methods and apparatuses are not only realized by the exemplary embodiment of the present invention, but, on the contrary, are intended to be realized by a program for realizing functions corresponding to the configuration of the exemplary embodiment of the present invention or a recording medium for recording the program.
[0046] While this invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.
[0047] According to the exemplary embodiment of the present invention, since a base station uses a two dimensional state function matrix having state functions as elements rather than using the if-then-else and case sentences when performing call connection control of a terminal, a call connection control processing speed may be increased.
[0048] In addition, since call states and received messages are used as indexes of a state function matrix and a state function corresponding to the call state and the received message is performed, call control processing performance at the base station may be increased.
[0049] Further, since the state function is maintained to be the two dimensional function matrix, the state function may be easily added, deleted, and modified.
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The present invention relates to a call connection control method used by defining a state function matrix when a base station controls call connection of a terminal, and a method for generating the state function matrix. In a call connection process, a call state varies and an access point control subsystem receives messages from a terminal and an access point traffic subsystem. The access point control subsystem calls a state function corresponding to the received message and a current call state among a plurality of state functions that are respectively mapped to a plurality of elements of the state function matrix when receiving the message, and operates the state function. The state function matrix may include a plurality of call states as one index among row and column indexes, and a plurality of messages as the other index.
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BACKGROUND OF THE INVENTION
This invention relates to a clothes dryer hanging feature for permitting the hanging of certain objects within a clothes dryer so that they will be exposed to the hot air of the clothes dryer, but will not be tumbled with the rotating drum.
Sometimes it is desirable to dry objects which are hard or irregularly shaped. If these objects are placed within the rotating drum of a conventional clothes dryer they make loud noises during tumbling, and may damage the interior structure of the clothes dryer during the tumbling action. An example of such objects might be sneakers or shoes which have become wet and require drying.
Therefore a primary object of the present invention is the provision of an improved clothes dryer having a hanging feature for hanging objects within the dryer.
A further object of the present invention is the provision of a hanging feature which permits objects to be suspended within the clothes dryer without tumbling in response to the rotation of the clothes dryer drum.
A further object of the present invention is the provision of a hanging feature which permits the objects to hang over the door plug of the clothes dryer and directly over the lint filter area of the dryer so as to allow heated air flow to pass directly over them in a drying fashion.
A further object of the present invention is the provision of a hanging feature for a clothes dryer that permits objects to be dried at the same time as items placed on a separate rack.
A further object of the present invention is the provision of a hanging feature which eliminates the need for a separate rack in the drying chamber.
A further object of the present invention is the provision of a clothes dryer hanging feature which is efficient, economical to manufacture, and durable in use.
SUMMARY OF THE INVENTION
The foregoing objects may be achieved by a clothes dryer which includes a top wall, side walls, a rear wall, and a front wall, one of the walls having a cabinet opening therein. A drying container is contained within the cabinet and has a drying cavity for containing clothing or other fabrics to be dried and a container opening registering with the cabinet opening of the cabinet to provide access to the drying cavity from outside the cabinet.
A door is hinged to the cabinet for pivotal movement about a hinge axis from a closed position in covering relation over the cabinet opening to an open position permitting clothing to be placed in the dryer container through the cabinet opening and the container opening. A hanger is on either the door or the cabinet at a location adjacent the cabinet opening. The hanger is adapted to permit the hanging of an article to be dried in a hanging position which exposes the article to the drying chamber of the drying container when the door is in its closed position.
BRIEF DESCRIPTION OF THE FIGURES OF THE DRAWINGS
FIG. 1 is a perspective view of a dryer having the hanging feature of the present invention.
FIG. 2 is a sectional view taken along line 2--2 of FIG. 1.
FIG. 2A is an enlarged detail view of a portion of FIG. 2 taken along line 2A--2A.
FIG. 3 is a sectional view taken along line 3--3 of FIG. 2.
FIG. 3A is a front elevational view taken along line 3A--3A of FIG. 3.
FIG. 4 is a sectional view of a modified form of the hanging feature.
FIG. 4A is a sectional view taken along line 4A--4A of FIG. 4.
FIG. 5 is a sectional view of a modified form of the hanging feature.
FIG. 5A is a sectional view taken along line 5A--5A of FIG. 5.
FIG. 5B is a view similar to FIG. 5A but showing still a further modified form of the hanging feature.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawings the numeral 10 generally designates a clothes dryer having a top 12, sides 14, front 16, rear 18 (FIG. 2), and bottom 20. A control panel 22 is provided at the rear of the top 12 in conventional fashion. An access opening 24 is provided in the front 16 also in conventional fashion.
A door 26 is hinged at one of its sides by hinges 27 to swing from an open position as shown in FIG. 1 to a closed position as shown in FIG. 2. A pair of shoes 28 are shown suspended by their shoe strings 30 from a door hanging feature 66 which will be described in greater detail hereafter.
Top 12 and front 16 of clothes dryer 10 are provided with a door indentation 32 for receiving the door 26 in its closed position. Door indentation 32 includes a top surface 34, side surfaces 36, and a bottom surface 37.
Referring to FIGS. 2 and 2A the door opening 24 is surrounded by a door skirt 38 having a top front surface 40, a bottom front surface 42, a top interior skirt extension 44, and a bottom interior skirt extension 46. A drum 48 is rotatably mounted within the clothes dryer 10 and is adapted to rotate and tumble clothing in conventional fashion during the time that it is being dried.
The door 26 includes a top panel 50, a front panel 52, and an inner panel 54. Inner panel 54 is comprised of a plug portion 56, an upper portion 58 and a lower portion 60. A seal 62 extends around the plug portion 56 and is shown in FIG. 2 in cross section at the upper edge of plug 56 and at the lower edge of plug 56.
The hanging feature 66 is shown in FIG. 2A to be formed of an indentation 68 which includes bars 70 (FIGS. 3 and 3A) located across its front and which includes three openings 72, 74, 76 intersposed between the bars 70.
The method for using the hanging feature 66 is to insert the strings 30 of the shoes 28 into the side openings 72, 76 and to tie them together into a knot 78 which then is permitted to recess into the indentation 68. The shoes 28 then are suspended in the position shown in FIGS. 2 and 2A so that they are exposed to the interior of the drum 48, but are not permitted to tumble within the drum 48. The shoes 28 are shown suspended immediately above a perforate outlet duct 86 supporting a removable filter 88. This permits the hot air indicated by arrows 90 to pass from the drum 48 over the shoes 28, into the outlet duct 86 and through the filter 88. The shoe strings 30 pass from the hanging feature 66 downwardly between the seal 62 and the top front surface 40 of the door skirt 38. They do not seriously disrupt the sealing function provided by door seal 62.
The hanging feature 66 is shown to be provided in the indentation 68 of inner panel 54. However, the hanging feature 66 could alternatively be provided in the front surface 40 of the skirt 38 without detracting from the invention.
Referring to FIGS. 4-4A, a modified form of the hanging feature is shown and is comprised of a rectangularly shaped hook 80 which is molded in the upper portion 58 of the inner door panel 54.
FIG. 5-5A shows another modified form of the invention which includes a hook 82 which is straight and does not have a right angle bend such as shown for hook 80 in FIGS. 4-4A.
FIG. 5B shows another form which can be made for the hook, including a rounded shape such as shown by hook 84.
In the drawings and specification there has been set forth a preferred embodiment of the invention, and although specific terms are employed, these are used in a generic and descriptive sense only and not for purposes of limitation. Changes in the form and the proportion of parts as well as in the substitution of equivalents are contemplated as circumstances may suggest or render expedient without departing from the spirit or scope of the invention as further defined in the following claims.
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A hanging feature is provided for a clothes dryer. The hanging feature is included on the door, or on the cabinet adjacent the door opening so that shoes or other objects can be hung from the hanging feature and suspended in a position exposed to the hot air within the rotating drum while at the same time being held free from rotation with the rotating drum.
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BACKGROUND OF THE INVENTION
[0001] The present invention relates to a grommet. For example, the invention relates to a grommet that is provided between two fixing plates such as those of the body and the back door of a vehicle to protect a long member that is cabled between the two fixing plates.
[0002] As shown in FIG. 5, a wire harness 103 that is cabled between a body 101 and a back door 102 of a vehicle 100 is covered with a grommet 105 .
[0003] Providing the grommet 105 between the body 101 and the back door 105 and covering the wire harness 103 with the grommet 105 prevents the wire harness 103 from being exposed to outside when the back door 102 is opened.
[0004] The grommet 105 has, at the two ends, a body-side fixing portion 111 to be engaged in a fixing hole 10 (see FIGS. 6 A- 6 E) of the body 101 , a door-side fixing portion 112 to be engaged in a fixing hole 107 of the back door 102 and a bellows-shaped connection pipe 113 connecting the body-side fixing portion 111 and the door-side fixing portion 112 so as to be integral with those.
[0005] The body-side fixing portion 111 and the door-side fixing portion 112 are approximately identical members. In the following, only the door-side fixing portion 112 will be described (the description of the body-side fixing portion 111 will be omitted).
[0006] To attach the grommet 105 to the body 101 and the back door 102 , the grommet 105 in which the wire harness 103 is fitted is inserted into the fixing hole 106 of the body 101 from inside the body 101 as shown in FIG. 6A and then taken out to the space between the body 101 and the back door 102 as shown in FIG. 6B.
[0007] After a tip portion 103 A of the wire harness 103 is inserted into the fixing hole 107 of the back door 102 , the door-side fixing portion 112 is put into the space inside the back door 102 through the fixing hole 107 as shown in FIGS. 6 C- 6 E. Then, the door-side fixing portion 112 of the grommet 105 is engaged into the fixing hole 107 of the back door 102 , whereby the grommet 105 is attached to the back door 102 .
[0008] As shown in FIG. 7, to allow the wire harness 103 to pass through and be held by the fixing hole 107 (see FIGS. 6 A- 6 E) of the back door 102 , the door-side fixing portion 112 of the grommet 105 is provided with an outer member 121 and an inner member 120 . The outer member 121 has a pipe-shaped insertion portion 115 that is to be inserted into the fixing hole 107 and into which the wire harness 103 can be inserted, a brim-shaped close contact portion 116 that extends outward from the insertion portion 115 and is to come into close contact with the front face of the back door 103 , a pressure contact portion 117 that is provided outside the insertion portion 115 and is to come into pressure contact with the back face of the back door 102 , and a groove 118 that is formed by the inside face of the dose contact portion 116 . The inner member 120 is generally shaped like a disc having a central opening and is inserted in the groove 118 . The inner member 120 is provided outside a pipe-shaped guide portion 119 .
[0009] In general, the inner member 120 is generally elliptical in a plan view. The inner member 120 can easily be inserted into the groove 118 of the close contact portion 116 of the door-side fixing portion 112 by first inserting a portion, on its major axis 120 A, of the inner member 120 into the groove 118 .
[0010] By the way, as shown in FIG. 6D, the wire harness 103 is bent so as to go over a tip portion 119 A of the guide portion 119 of the door-side fixing portion 112 . Therefore, the wire harness 103 projects from the tip portion 119 A of the guide portion 119 by a relatively large projection length L.
[0011] As a result, the wire harness 103 may hit the backdoor 102 in inserting the door-side fixing portion 112 of the grommet 105 into the fixing hole 107 of the back door 102 . The work of attaching the grommet 105 to the back door 102 may take long time.
SUMMARY OF THE INVENTION
[0012] It is therefore an object of the present invention to provide a grommet capable of preventing a wire harness from hitting a fixing plate in inserting the grommet into a fixing hole of the fixing plate.
[0013] In order to achieve the above object, according to the present invention, there is provided a grommet through which a long member is passed and mounted on a fixing hole of a fixing plate, comprising;
[0014] a cylindrical insertion portion, through which the long member is passed;
[0015] a brim-shaped close contact portion, extending outward from the insertion portion and having a mounting groove which is mounted on an edge of the fixing hole; and
[0016] a cylindrical guide portion, having a through hole to path through the long member, and concentrically connected to the insertion portion such that the guide portion is projected from the fixing plate when the grommet is mounted to the fixing plate,
[0017] wherein the guide portion is provided with a cut portion so as to accommodate a part of the long member.
[0018] In the grommet, the guide portion may be molded either integrally with or separately from the insertion portion and the dose contact portion.
[0019] More specifically, the grommet according to the invention may be such that it is provided with an outer member having the insertion portion and the close contact portion and an inner member that is generally shaped like a disc having a central opening and can be inserted in a groove formed by the inside surface of the close contact portion, and that the inner member is provided with the guide portion.
[0020] In the above configuration, the guide portion is formed with the cut portion capable of accommodating the long member at least partially. Accommodating the long member In the cut portion of the guide portion makes it possible to reduce the projection length of the long member from the top of the guide portion.
[0021] Therefore, the long member is prevented from hitting the fixing plate in inserting the grommet into the fixing hole of the fixing plate.
[0022] Preferably, the guide portion is shaped into an elliptical shape in a plan view, and the cut portion is provided along a major axis direction of the guide portion.
[0023] In general, where the guide portion is generally elliptical in a plan view, when the long member is pulled out of the guide portion of the grommet, the long member is pulled along the major axis of the guide portion.
[0024] In the above configuration, the guide portion is generally elliptical shape in a plan view and the cut portion is formed on the major axis of the guide portion. This makes it possible to easily accommodate the long member in the cut portion in pulling the long member out of the guide portion.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] The above objects and advantages of the present invention will become more apparent by describing in detail preferred exemplary embodiments thereof with reference to the accompanying drawings, wherein:
[0026] [0026]FIG. 1 is a side view of a grommet according to the invention;
[0027] [0027]FIG. 2 is an exploded perspective view of an important part of the grommet according to the invention;
[0028] [0028]FIG. 3 is a sectional view of the important part of the grommet according to the invention;
[0029] [0029]FIG. 4 is a side view of an important part of the grommet according to the invention;
[0030] [0030]FIG. 5 is a perspective view showing a state that a related grommet is attached to a vehicle;
[0031] FIGS. 6 A- 6 E illustrate a procedure for attaching the related grommet to the vehicle.
[0032] [0032]FIG. 7 is an exploded perspective view of an important part of the related grommet; and
[0033] [0033]FIGS. 8A and 8B illustrate a mechanism of the related grommet.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0034] An embodiment of the present invention will be hereinafter described with reference to FIGS. 1 - 4 . Members etc. of the following embodiment in FIGS. 1 - 4 that have the same or corresponding ones in FIG. 5 to FIG. 7 are given the same or corresponding symbols as the latter and will be described in a simplified manner or will not be described.
[0035] As shown in FIG. 1, a grommet 10 according to the embodiment is composed of a body-side fixing main body 20 for allowing a wire harness (long member) 15 to pass through and be held by a fixing hole 13 formed in a fixing plate 12 of a vehicle body 11 , a door-side grommet main body 30 for allowing the wire harness 15 to pass through and be held by a fixing hole 18 formed in a fixing plate 17 of a back door 16 , and a connection member 38 that connects the body-side fixing main body 20 and the door-side grommet main body 30 .
[0036] As shown in FIGS. 1 - 2 the body-side fixing main body 20 has an outer member 40 and an inner member 27 .
[0037] The outer member 40 has a pipe-shaped insertion portion 21 that is to be inserted into the fixing hole 13 of the vehicle body 11 and into which the wire harness 15 can be inserted, a brim-shaped dose contact portion 22 that extends outward from the insertion portion 21 and is to come into close contact with a front face 12 A of the fixing plate 12 , a pressure contact portion 25 that is provided outside the insertion portion 21 and is to come into pressure contact with a back face 12 B of the back door 12 , and a groove 23 that is formed by an inside face 21 B of the close contact portion 21 .
[0038] On the other hand, the inner member 27 is generally shaped like a disc having a central opening and is inserted in the groove 23 . The inner member 27 is connected to the outer member 40 so as to be concentric with the insertion portion 21 and extends outward from an outer circumferential face 26 A of a pipehaped guide portion 26 that projects to at least one of the spaces on the front side and the back side (in this embodiment, the back side) of the fixing plate 12 .
[0039] As shown in FIG. 2, the guide portion 26 has a pipe-like shape that is generally elliptical in a plan view, and has, on the side of an open-end face 26 B and on its major axis 28 A, a cut portion 26 C capable of accommodating the wire harness 15 at least partially.
[0040] The inner member 27 , which is generally elliptical in a plan view, extends from the outer circumferential face 26 A of the guide portion 26 . A plurality of (first to third) projections 29 A, 20 B, and 29 C project from a periphery 27 A of the inner member 27 in such directions as to cross the minor axis 28 B of the inner member 27 .
[0041] Among the first to third projections 29 A, 20 B, and 29 C, the first and second projections 29 A and 29 B project in such directions as to also cross the major axis 28 A of the inner member 27 . In addition, the outer circumferential face 26 A of the guide portion 26 is formed with a locking claw 26 D for causing the guide portion 26 to be held by the fixing plate 12 when the locking claw 26 D is locked into the fixing hole 13 of the fixing plate 12 via the dose contact portion 22 and the pressure contact portion 25 .
[0042] In general, to insert the inner member 27 , which is generally elliptical in a plan view, into the groove 23 of the close contact portion 22 of the body-side grommet main body 20 , first a portion, on its major axis 28 A, of the Inner member 27 is inserted into the groove 23 in a direction indicated by an arrow in FIG. 2.
[0043] As shown in FIG. 1, the door-side grommet main body 30 has a pipe-shaped insertion portion 31 that is to be inserted into the fixing hole 18 of the back door 16 and into which the wire harness 15 can be inserted, a brim-shaped dose contact portion 32 that extends outward from the insertion portion 31 and is to come into close contact with a front face 17 A of the fixing plate 17 , a pressure contact portion 35 that is provided outside the insertion portion 31 and is to come into pressure contact with a back face 17 B of the back door 17 , and a pipe-shaped guide portion 36 that is molded integrally with the close contact portion 35 and projects to at least one of the spaces on the front side and the back side of the fixing plate 17 .
[0044] The connection member 38 generally assumes a pipe-like shape so as to be able to accommodate the wire harness 15 and has a bellows like shape in detail. Therefore, the connection member 38 can be bent into a desired shape and hence the grommet 10 can easily be provided between the fixing plate 12 of the vehicle body 11 and the fixing plate 17 of the back door 16 .
[0045] In the grommet 10 having the above structure, the first to third projections 29 A- 29 C which project from the periphery 27 A of the inner member 27 are wrapped with the close contact portion 22 .
[0046] This allows the close contact portion 22 to have a great wrapping length W2 (see FIG. 3), whereby the dose contact portion 22 of the body-side grommet main body 20 can be prevented from being turned up.
[0047] Since the only change is that the first to third projections 29 A- 29 C are provided so as to project from the periphery 27 A of the inner member 27 , the inner member 27 project only partially and the first to third projections 29 A- 29 C can be made compact.
[0048] This prevents the close contact portion 22 that covers the inner member 27 from interfering with the fixing plate 12 when the body-side grommet main body 20 is caused to pass through the fixing hole 13 of the fixing plate 12 .
[0049] The inner member 27 is generally elliptical in a plan view and the first to third projections 29 A- 29 C project in such directions as to cross the minor axis 28 B of the inner member 27 as shown in FIG. 2.
[0050] This allows the first projection 29 A and the second projection 29 B to be inserted first Into the groove 23 in a direction indicated by an arrow in FIG. 2 when the inner member 27 is inserted into the groove 23 of the close contact portion 22 . In this manner, the inner member 27 can easily be inserted into the groove 23 of the close contact portion 22 .
[0051] Since the first projection 29 A and the second projection 29 B project in such directions as to cross the major axis 28 A of the inner member 27 , both of the lengths L1 and L2 of the inner member 27 along the major axis 28 A and the minor axis 288 , respectively, can be reduced as shown in FIG. 2.
[0052] Therefore, the size of the inner member 27 can be reduced, that is, it can be made compact. This prevents the close contact portion 22 of the body-side grommet main body 20 that covers the inner member 27 from interfering with the fixing plate 12 when the body-side grommet main body 20 of the grommet 10 is caused to pass through the fixing hole 13 of the fixing plate 12 .
[0053] In addition, since a plurality of (three) projections, that is, the first to third projections 29 A- 29 C, are provided, a large total overlap region can be secured between the inner member 27 and the close contact portion 22 . This efficiently prevents the dose contact portion 22 of the body-side grommet main body 20 from being turned up.
[0054] In the grommet 10 having the above structure, as shown in FIG. 2, the open-end face 26 B of the guide portion 26 is formed with the cut portion 26 C capable of accommodating the wire harness 15 at least partially.
[0055] Accommodating the wire harness 15 in the cut portion 26 C of the guide portion 26 as shown in FIG. 4 can reduce the projection length L3 of the wire harness 15 from the open-end face 26 B of the guide portion 26 .
[0056] Therefore, the wire harness 15 is prevented from hitting the fixing plate 12 when the body-side grommet main body 20 is inserted Into the fixing hole 13 of the fixing plate 12 . This makes it possible to attach the body-side grommet main body 20 of the grommet 10 to the fixing plate 12 easily without taking much time.
[0057] Further, as shown in FIG. 2, the guide portion 26 is generally elliptical in a plan view and is formed with the cut portion 26 C on the major axis 28 A of the guide portion 26 . This makes it possible to accommodate the wire harness 15 in the cut portion 26 C as shown in FIG. 4 easily without taking much time in pulling the wire harness 15 out of the guide portion 26 .
[0058] Although the above embodiment is directed to the case that the body-side grommet main body 20 and the door-side grommet main body 30 of the grommet 10 have different structures, the inversion Is not limited to such a case. For example, the door-side grommet main body 30 may be given the same structure as the structure of the above-described body-side grommet main body 20 .
[0059] Although the above embodiment is directed to the case that the long member is the wire harness 15 and the fixing plates are parts of a vehicle, the long member is not limited to a wire harness and the fixing plates are not limited to parts of a vehicle.
[0060] Although the above embodiment is directed to the case that the plurality of projections are the three projections 29 A- 29 C, the number of projections is not limited to three and may be an arbitrary number.
[0061] The invention is not limited to the above-described embodiment and proper modifications, improvements, etc. are possible. The material, shape, dimensions, form, number, locations, thickness, eta of each of the grommet, fixing plates, long member, eta are not limited to those exemplified in the embodiment and may be determined arbitrarily as long as the invention can be implemented.
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A grommet through which a long member is passed and mounted on a fixing hole of a fixing plate includes a cylindrical insertion portion, through which the long member is passed, a brim-shaped close contact portion, extending outward from the insertion portion and having a mounting groove which is mounted on an edge of the fixing hole, and a cylindrical guide portion, having a through hole to path through the long member, and concentrically connected to the insertion portion such that the guide portion is projected from the fixing plate when the grommet is mounted to the fixing plate. The guide portion is provided with a cut portion so as to accommodate a part of the long member.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to positioning spacers in the manufacturing process for flat panel displays (FPD), and more specifically to use of a non-contact force (force at a distance) to position spacers on a desired position of field emission displays (FED).
[0003] 2. Description of the Related Art
[0004] In the technological procedure of manufacturing flat panel display, spacers are used to keep a specific distance between an anode plate and a cathode plate.
[0005] Field emission display (FED) is a kind of flat panel display attracting intense notice in recent years. The main reason is that it not only has the thin and light characteristics of a liquid crystal display (LCD), but also the high brightness and self emission advantages of cathode ray tube (CRT) displays.
[0006] The distance between the cathode plate and the anode plate relates directly to the voltage of the field emission. The spacers are used to keep the space between the cathode plate and the anode plate even. When the two plate package is subjected to vacuum, the pressure between the upper and lower plates has to be less than 10 torr to avoid the field emission electrons being affected by residual gas. In this situation, the upper and lower plates reach a condition of intense vacuum, and the space will not be even. If the space between the two plates is not even, it will impact quality and lifetime of the display. Putting spacers between the two plates can effectively keep the space even and therefore maintain the electron field homogeneity and improve vacuum efficiency.
[0007] The traditional method of positioning spacers in the flat panel display is to use a mechanical arm to grasp spacers. The mechanical arms use two or more contact points to position spacers in a desired location with contact forces. This method is not easy because the arms have to align the spacers, lengthening the processing time and slowing down production. In addition, the spacers are easily damaged in this process.
[0008] The thickness of the spacers' cross section directly affects the resolution of display (the cross sections of spacers are non-emission area). Therefore, using spacers of high aspect ratio is a popular trend in the production of field emission display.
[0009] The spacers are gradually reduced to a very thin profile, such that the method using mechanical arms is not suitable. Vacuum chuck (adsorption) technology is also applied to several processes in production of flat panel display such as the absorption of glass substrates and electrode boards. Even though vacuum chuck technology can avoid the damage to adsorbed substrates, it cannot be applied to grasping spacers, since the spacers form comb or grid shapes; their hollow structure and the smaller width (less than 100 μm) do not provide adequate flat surface for vacuum chuck contact. Thus, vacuum chuck technology is not used extensively in spacer positioning for field emission display.
SUMMARY OF THE INVENTION
[0010] Accordingly, the main object of the present invention is to provide an inductive procedure that improves on conventional contact procedures to position display spacers. The inductive attraction used are non-contact forces, comprising magnetic forces and electrostatic forces.
[0011] In order to achieve the above object, the present invention provides a method of relocating spacers using inductive attraction. The procedures involved use inductive attraction such as magnetic force and electrostatic force to position display spacers. Using inductive attraction prevents the structure of spacers from being damaged, saves time, and accelerates the production rate of field emission display by eliminating the need for spacers to be positioned before relocation. The present invention includes providing attractable spacers, using an inductive procedure (either magnetic or electrostatic procedure) with an inductive chuck to position (attract) spacers, and re-positioning the spacers in a desired location of a substrate using the inductive chuck.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The present invention can be more fully understood by reading the subsequent detailed description in conjunction with the examples and references made to the accompanying drawings, wherein:
[0013] [0013]FIG. 1A through 1C are schematic diagrams of the spacers using the inductive electrostatic method;
[0014] [0014]FIG. 2 is a schematic diagram of a spacer with magnetic materials attached thereto;
[0015] [0015]FIG. 3 is a schematic diagram of a spacer with magnetic materials deposited thereon;
[0016] [0016]FIG. 4A˜ 4 C are schematic diagrams illustrating the use of inductive magnetic method to position the spacers;
[0017] [0017]FIG. 5 is cross section of FIG. 1C along line 5 - 5 ′.
DETAILED DESCRIPTION OF THE INVENTION
[0018] The present invention relates to a method of using inductive attraction to position spacers in the process of manufacturing field emission displays. This inductive procedure uses magnetic or electrostatic forces to position or attract spacers rather than using direct contact.
[0019] The substrate to receive spacers can be a flat panel display's upper or lower plates, such as a field emission display's anode or cathode plates.
[0020] The spacers between the anode and cathode plates maintain even space between the two boards. Therefore space between the two boards under intense vacuum pressure (less than 10− 6 torr) can be even, so that the display quality is not affected.
[0021] The inductive method uses non-contact forces including magnetic or electrostatic forces to position or attract spacers.
[0022] Inductive or attractable spacers are spacers that can be attracted by inductive attraction (such as magnetic or electrostatic forces). The inductive spacers are usually spacers composed totally or partially of materials that can be attracted by inductive attraction. Spacers can use magnetic (Fe, Co, Ni, or alloys thereof) or electrostatic materials for entire or partial composition, others can be structured in two or more layers with at least one layer of electrostatic or magnetic material, or have magnetic materials deposited thereon. Spacers can also be made of dielectric, ceramic, or glass materials.
[0023] The spacers applied to field emission display that use magnetic adsorption procedures can be cylindrical, X-, I-, L-, or bar-shaped or a combination thereof. The spacers can also be structured with two or more cross-points such as comb, lattice, grid, or zig-zag shaped or a combination thereof.
[0024] The spacers applied to field emission display using electrostatic adsorption procedures can be cylindrical, X-, I-, L-, or bar-shaped, comb, lattice, grid, or zig-zag shaped or a combination thereof. Among the different shapes, those structures with two or more cross points are preferred.
[0025] When grabbing spacers with the method according to the present invention, the spacers can be precisely positioned on a substrate using an alignment step. A charge-coupled device (CCD) or alignment marks can be used to detect the exact required relative positions of the chuck and the substrate.
[0026] The following embodiments are intended to illustrate the invention more fully without limiting their scope, since numerous modifications and variations will be apparent to those skilled in this art.
First Embodiment
[0027] [0027]FIGS. 1A through 1C show the steps of positioning spacers using the inductive electrostatic method. In FIG. 1A, the grid shaped rubber spacer 120 (with the thickness of 1000 μm) is put on a flat surface with its adopted face upward. It is then attracted to an electrified, gradually descending ceramic electrostatic chuck 110 .
[0028] In FIG. 1B, a substrate, preferably comprising the display's upper or lower plate, is provided. In this embodiment, it is a field emission display's anode plate 130 with phosphor layers 132 and black matrix layers 134 . Next, the spacer 120 is lifted by the attractive chuck 110 and aligned precisely with the field emission display's anode plate 130 . A Charge-Coupled Device (CCD) can check the alignment marks on the attractive chuck 110 (or spacer 120 ) and the field emission display's anode plate 130 . The alignment step can also be accomplished by a spacer alignment machine.
[0029] In FIG. 1C, the voltage supply to the attractive chuck 110 is interrupted and the spacer 120 is released onto the black matrix layer 134 after precise alignment. The attractive chuck is removed, completing the process.
Second Embodiment
[0030] [0030]FIG. 4A through FIG. 4C show the steps of positioning spacers used in the inductive magnetic method. In FIG. 4A, a comb shaped, dielectric spacer 420 with attached or deposited magnetic materials thereon (including Fe, Co, Ni, or alloys thereof) is provided with its adopted face upward, as shown in FIG. 2 and FIG. 3. Next, an electromagnetic chuck 410 with several magnetic metal bands 412 thereon is electrified and then gradually lowered to attract the spacer 420 by means of the aforementioned magnetic materials thereon. The magnetic force of the electromagnetic chuck 410 can be adjusted by the amount of electric current.
[0031] In FIG. 4B, a substrate preferably comprising the display's upper or lower plate is provided. In this embodiment, it is a field emission display's cathode plate 430 . Next, the spacer 420 is lifted by the electromagnetic chuck 410 and aligned precisely with the field emission display's anode plate 130 . A Charge-Coupled Device (CCD) can check the alignment marks on the attractive chuck 410 (or spacer 420 ) and the field emission display's cathode plate 430 . The alignment step can also be accomplished by a spacer alignment machine.
[0032] In FIG. 4C, the voltage supply to the electromagnetic chuck 410 is interrupted and the spacer 420 is released onto the desired position of the cathode plate 430 after precise alignment. The electromagnetic chuck 410 is then removed, completing the process.
[0033] In summary, compared with previous technology, the present invention has the following advantages. The invention's use of an inductive procedure (magnetic or electrostatic adsorption) rather than contact forces to position (adsorb) spacers takes less time to reposition spacers, speeding throughput. The inventive procedure avoids damage to the spacers by contact forces keeping the spacers intact. Finally, the spacers are not restricted to specific structures with the attractive chuck can be exchanged according differing spacer sizes and shapes.
[0034] Although the present invention has been particularly shown and described above with reference to two 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 alteration and modifications as fall within the true spirit and scope of the present invention. What is claimed is:
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A method of relocating spacers using inductive attraction. A chuck employs the inductive attraction to lift field emission display (FED) spacers, wherein the spacers are provided with susceptibility to the employed attraction. The spacers are lifted by the chuck and relocated to a desired position. The inductive process uses a non-contact force, including electrostatic and magnetic forces.
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BACKGROUND AND SUMMARY OF THE INVENTION
[0001] The present invention relates generally to an optical media or material capable of transmitting an optical signal and, more specifically, to such a material and a method of making a material which is hydroxyl ion (OH) and hydrogen (H) resistant.
[0002] Silicon dioxide glass or silica is one form of glass used in optical fibers because of its clarity. Other optical materials including silicon have been used. Silicon based fiber has transmission losses. These transmission losses have three components: OH absorption, Rayleigh scattering and the Urbach tail.
[0003] Silicon based material is a hydrophilic material, which absorbs OH. This absorption produces transmission losses. The transmission losses in general are shown as graph 10 in FIG. 1 from Ref. 1. That is a graph of transmission losses as a function of wavelength. OH absorption produces the peak at approximately 1400 nanometers, which is approximately one-half of the fundamental OH mode. The Rayleigh scattering effect is illustrated by curve 12 . Rayleigh scattering is proportional to 1/λ 4 . Thus, the Rayleigh scattering is wavelength or λ dependent. The scattering comes from the non-uniformities in the glass, which is disordered by its nature, even though the purity and homogeneity are carefully controlled during manufacturing. Light will scatter from any point where the refractive index varies. The Urbach contribution, as illustrated, produces the Urbach tail 14 beginning at approximately 1,600 nanometers. This results from the vibration of the silicon-oxygen (S—O) bond. The solid line 16 running across the bottom represents the sum of the Rayleigh and Urbach contributions, which may be the clarity limit in the silicon based glass.
[0004] Spatial spreading of light along the path of propagation is known as dispersion. Appropriate doping can be used to control dispersion. The dopant changes the index of refraction of the fiber by raising the index refraction. Confinement process is similar to internal refraction. Which dopant to use and how it is added is used to optimize all of the parameters associated with high capacity optical transmission systems. The particular configuration will determine the optimization of the interplay between dispersion and non-linearity.
[0005] The dependence of the loss mechanism on spectral wavelengths of silica standard (single) mode fibers SMF is illustrated in FIG. 2A. A comparison of the modal dispersion of transmitted signals in multimode and single-mode fibers is illustrated in FIG. 2B. See Ref 2.
[0006] Historically, optical systems have been designed around these limitations of the optical fiber by applying certain modifications and optimizations such as such as dispersion compensators, in-line amplifiers, etc. So, to reduce the transmission loss of fibers, various schemes have been used. These include cladding the basic fiber. Refs. 3 and 4 show two of the latest treatments to reduce intrinsic fiber loss.
[0007] Ref. 5 and Ref. 6 were one of the earliest attempts in doping silicon to produce a relatively high transmittance optical filter at desired wavelengths with relatively inexpensive cost, but still susceptible to water, as it is the case in the previous two Refs. Ref. 6 is the process used in Ref 5. Si and Te were heated at 1075° C. for 72 hours. The resulting structure of SiTe 2 had to be kept in a vacuum to prevent decomposition in the atmosphere through the interaction with water vapor. These are either costly in material cost, and or as well in the cost of manufacturing. More recent analysis is presented in Ref 7.
[0008] The present invention is a method of forming a single crystalline structure having a substantially linear response at least over the wave lengths of 1,200 to 1,700 nanometers, the resulting structure and its use as an optical media. Thus, maximum obtainable transmission with zero attenuation is provided. There is no intrinsic material absorption.
[0009] For silicon base materials, the method produces a hydroxyl ion (OH) resistant silicon material. The transmission versus wavelength response is flat with no absorption peaks between 1,000 nanometers to the Urbach tail at 2,000 nanometers, at a minimum. There is no second harmonic of the hydroxyl ion vibration peak at 1,400 nanometers. The Rayleigh scattering has been substantially eliminated.
[0010] An example of a silicon based material produced by the present method is a silica-tellurium single crystalline structure. The structure is SiO 2 Te x where x is in the range of ⅓ to {fraction (5/3)}. The silica and tellurium structure includes twin crystal structures. The twining angle is 90 degrees. The method also includes silicon-tellurium single crystalline structures.
[0011] One method of the invention includes inserting two substances into a crucible and sealing the crucible in an envelope. The two substances are in an oven at a temperature and time sufficient to create a single crystalline material of the two substances having a substantially linear response at least over the wave lengths of 1,200 to 1,700 nanometers.
[0012] Another method includes inserting the two substances into a substantially spherical crucible. The crucible is sealed in a substantially spherical envelope. The two substances are heated in an oven at a temperature and time sufficient to create a single crystalline material of the two substances. Heating is carried out for a sufficient amount of time that all of the inserted material is converted to a single crystalline material of the two substances. The opening in the crucible should be large enough to receive the substances while maintaining the crucible spherical. For example, the diameter of the crucible is at least twice the diameter of an opening of the crucible through which the substances are inserted.
[0013] The resulting material of both methods are an aggregate of single crystalline material. The resulting material of either product may then be processed into an optical media. The material may also be used as a protective coating on metal or ceramics. This may be a crystal, wafer, rod or a fiber. No cladding or other treatment is necessary to obtain the transmission characteristics briefly described.
[0014] These and other aspects of the present invention will become apparent from the following detailed description of the invention, when considered in conjunction with accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] [0015]FIG. 1 is a graph illustrating the transmission loss per wavelength in a standard mode silica optical fiber as the signal propagate in the fiber.
[0016] [0016]FIG. 2A is another graph illustrating the loss mechanism on a spectral wavelength of standard mode silica optical fibers.
[0017] [0017]FIG. 2B is a comparison of the modal dispersion of transmitted signals in multimode and single-mode fibers.
[0018] [0018]FIG. 3 is a flow chart of a process according to the present invention.
[0019] [0019]FIG. 4A is an exploded view of the crucible and the substances as part of the loading process according to the present invention.
[0020] [0020]FIG. 4B is an assembled view of the crucible and the substances for FIG. 4A.
[0021] FIGS. 5 A- 5 C show the process of enclosing the crucible in the envelope according to the present invention.
[0022] [0022]FIG. 6 is an enlarged view of the resulting aggregate material with a broken crucible.
[0023] [0023]FIGS. 7A and 7B are scanning electron microscope photographs showing the aggregate of single crystalline structures at 200 and 20 micron resolution respectively.
[0024] [0024]FIG. 7C is a micro-spectrophotograph of single crystalline structures after processing at 5 micron resolution.
[0025] [0025]FIG. 8 is a graph of the X-Ray Diffraction showing the structures in the powder resulting material.
[0026] [0026]FIG. 9 is a FTIR transmission response of sixteen crystals of the material of FIGS. 7C and 8.
[0027] [0027]FIG. 10 is a FTIR transmission response of three of the sixteen crystals of FIGS. 9.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0028] The process as illustrated in FIG. 3 includes preparing the mixture of the two components at 20 which are to form the single crystalline material. The prepared material is then inserted in a crucible at 22 . The crucible is sealed in an envelope at 24 . The material is heated at 26 at a temperature and time sufficient to cause a single crystalline material of two substances to form. The time and temperature should be sufficient to cause all the material to form the single crystalline structure. The material is removed from the crucible in an envelope at 28 . The single crystalline material can then be processed into an optical transfer medium at 29 .
[0029] An example of a crucible is illustrated in FIGS. 4A and B as a hollow ball or sphere 30 . The ball or sphere 30 has at least one opening 31 . In the experiments run, the commercially available crucible 30 had a second opening 32 . Since a second opening 32 was in the crucible 30 , both openings 31 and 32 must be closed off in order to maintain the materials in the crucible. For the experiments run, as illustrated in FIGS. 4A and B, one sheets of material 33 provided to cap opening 32 . For example, the sheet 33 may be gold. If the second opening 32 does not exist, sheets 33 can be eliminated. Sample 34 is then put into crucible 30 and covered by sheet 35 and 36 . For example, the sheets 35 and 36 may be silver or gold. Finally, the total crucible 30 is wrapped in two sheets 37 and 38 , which may be silver. The resulting structure is illustrated in a cross-section in FIG. 4B.
[0030] The opening 31 in the crucible 30 should be large enough to receive the substances while maintaining the crucible spherical.
[0031] It should be noted that the material for the crucible 30 may be quartz, or gold, or silver, or other materials. Also, the covering materials 33 , 35 , 36 may also be quartz gauze, for example.
[0032] The wrapped crucible 30 is then placed in an envelope 50 , as illustrated in FIG. 5A. The envelope 50 is neck down at 52 and receives a tube 54 as shown in FIG. 5B. The interior of the envelope 50 is evacuated. The tube is removed from the envelope 50 and it is sealed at 56 as shown in FIG. 5C. The resulting structure is a generally spherical shape which resembles a tear drop. The processing of the envelope 50 to form the down 52 and closing it at 56 is performed with heat in a two-step method and sufficiently slow as not to preheat or affect the material in the crucible 30 . The envelope 50 may be quartz, for example.
[0033] As an example, the crucible 30 may be a ball or sphere having a diameter Dc of approximately 12 millimeter with at least one opening 32 , 33 having a diameter of approximately 3.5 millimeters. The diameter of the crucible Dc should be at least twice the diameter of the opening Do so as to maintain the spherical shape of the crucible. The resulting envelope 50 may have a diameter De of approximately 22 millimeters and a height of 50.8 millimeters. The thickness of the envelope 50 maybe approximately 1 millimeter.
[0034] Envelope 50 with a crucible 30 and the sample 34 therein is then inserted into an oven. It is heated at a sufficient temperature and time to create a single crystalline material of the sample or two substances. The time should also be sufficient such that all of the material forms a single crystalline material. The structure is an aggregate of the single crystals.
[0035] To continue the example, the sample 34 , crucible 30 and envelope 50 may be encased in a canister prior to being inserted into the oven. For this experiment, it was placed in a canister of nuclear industrial grade pipe steel. This is to protect the oven from any debris during the heating process. Also, it has been found that the canister extends the cooling time since it is also heated.
[0036] The canister is inserted into a cold oven. The oven was set, for example, to 800 degrees centigrade. The material was then cooked for five hours and then shut down to cool off. The cooling off period was until it was cool to the touch. This cool period was approximately 10 hours. The envelope 50 was cracked open. The temperature may be in a range of approximately 700 to 1000 degrees centigrade and the time in a range of approximately 3.5 to 7 hours. The temperature range may be above and or below the ionization temperature of the substances and be sufficient to generate single crystalline material. The specific time and temperature may depend on the material of the sample and the characteristics of the oven.
[0037] The example was used to form hydroxyl ion resistant silicon dioxide. For example, the molar proportions were SiO 2 Te 4/3 . As an example in making one gram of final product, 0.260 grams of silicon dioxide is combined with 0.38 grams of tellurium. The mixture is prepared by putting the two substances in, for example, an Agate mortar. The processed material is then formed into a tablet in a press. All or a portion of the tablet may be inserted into a crucible. For the time and temperature given, half of the tablet was used.
[0038] The results are illustrated in FIG. 6. Crucible 30 is shown as dark gray and the aggregate of the resulting material 60 is also shown in the ball as well as outside the ball. The aggregate had a whitish/grayish/brownish coloration with no distinct indication of separate silica and tellurium. The aggregate was somewhat brittle with crystalline surface observed in a microscope inspection. The single crystalline in a structure was twined. It had a twining angle of 90°.
[0039] Examples of the single crystalline SiO 2 Te 4/3 distribution of in the aggregate is shown in the FIGS. 7A and 7B from a scanning electron microscope at 200 and 20 micron resolution respectively. FIG. 7C shows a micro-spectrophotograph of single crystalline structures of SiO 2 Te 3/4 at 5 micron resolution after material scraped from the aggregate and then crushed or powdered. The black box is 5 microns on each side for a point of reference. The average micro-crystal size was 1 micrometer.
[0040] A x-ray diffraction test was performed to determine the structures present in the powder single crystalline material. As is noted, the identified crystal structures are: alpha-low quartz (SiO 2 ), alpha-low cristobalite (SiO 2 ), and an unidentified material structure. The closest recognizable material crystal structure to the unrecognizable material crystal structure based on a rerun of the results of the diffraction test using a greater variance is that of zinc oxide (ZnO). A comparison of the lattices of alpha low quartz, alpha low cristobalite and zinc oxide shows that the zinc oxide is hexagonal pyramidal, twined base to base while quartz is also hexagonal and cristobalite is cubic or tetragonal.
[0041] It should also be noted that quartz and cristobalite are tektosilicates. In nature they require temperatures above 1400 degrees centigrade and extreme pressure to form. The present method was performed well below this temperature and in a vacuum.
[0042] The resulting material can then be powdered or processed through a high-pressure press into a thin wafer, rod, cable or fiber form. No high heating step is required. Alternatively, it may be melted into a pre-form of a desired shape, pulled or further processed like other silicon dioxide materials. The single crystalline structure will not be altered by the pressing or the melting.
[0043] [0043]FIG. 9 shows the loss transmission of 16 samples of the above experiment as a function of wave number measure by an FTIR. The vertical scale is not a continuous percentage of loss, but is intended to show the substantially linear and/or flat response. Each vertical scale mark is 5%. Wave numbers 7000 to 5000 correspond to the 1,000 nanometer to 2,000 nanometer wavelengths. There is no spike due to the second harmonic of the hydroxyl ion, and there is no Urbach tail.
[0044] [0044]FIG. 10 illustrates the percentage transmission versus wave number for four selected samples. Again, even though the transmittance percentage varies, all of them are substantially flat. The difference in the transmittance is from the processing of the resulting material prior to the transmittance test. When the sample was pressed to a finer powder and less grainy, the transmission improved. An important aspect is that the response is flat and further techniques in preparing the sample for the measurement is expected to result in substantially 100 percent transmittance.
[0045] The formation of SiO 2 Te 4/3 is a new material produced by the present process, but the process may be used to produce other single crystal compounds of two substances. The material may be SiO 2 Te x where x is in the range of ⅓ to {fraction (5/3)}. The single crystalline material may be other silicon based materials for example silicon and telluride. The above process was conducted for SiTe 2 and produced similar results. But these are just examples and the process can be used with other substances.
[0046] It should also be noted that experiments have been conducted using silicon and silicon dioxide with tellurium in a rectangular crucible and a test tube shaped envelope at the same temperatures and times of the above example, but did not achieve the same results. Very few single crystals of the combined material were formed. The generally spherical shape of the crucible and the envelope produced the increased crystallization of all the material.
[0047] Not only is the material made from the present process OH resistant, but it is H 2 O and H. Thus, the present material may be used as a barrier on substrates, such as metal, ceramic or other surfaces, to protect against OH, H 2 O and H. The material would be powdered as previously discussed and applied to the surface of the metal or ceramics by known techniques depending on the metal or ceramic. This will prevent oxidation, surface defect and cracking of the surface of the metal and defects or cracking of the ceramic. The same is true for integrated circuit substrates and various metallic layers thereon.
[0048] Although the present invention has been described and illustrated in detail, it is to be clearly understood that this is done by way of illustration and example only and is not to be taken by way of limitation. The spirit and scope of the present invention are to be limited only by the terms of the appended claims.
References
[0049] 1. Gordon A. Thomas, et al., Physics in the Whirlwind of Optical Communications , Physics Today, pp. 30-36, September 2000.
[0050] 2 . Infrared Fiber Optics , Naval Research Laboratory, Washington, D.C.
[0051] 3. Ranka et al., U.S. Pat. No. 6,400,866 (Jun. 4, 2002).
[0052] 4. P. Fernández de Cordoba, et al., La nueva generación de fibras ópticas , El País, Jun. 5, 2002.
[0053] 5. E. G. Doni-Caranicola, et al., Use of single SiTe 2 crystals with a layered structure in optical filter design , J. Opt. Soc. Am., pp. 383-386 (1983).
[0054] 6. A. P. Lambros, et al., The Optical Properties of Silicon Ditelluride , Phys. Status Solidi (b), Vol. 57, No. 2, pp. 793-799 (1973).
[0055] 7. Kazuhisa Taketoshi, et al., Structural Studies on Silicon Ditelluride ( SiTe 2 ), Jpn. J. Appl. Phys., Vol. 34, pp. 3192-3197 (1995).
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A method of forming a single crystalline structure having a substantially linear response at least over the wave lengths of 1,200 to 1,700 nanometers, the resulting structure and its use as an optical media or a barrier coating. Thus, maximum obtainable optical transmission with zero attenuation is provided. There is no intrinsic material absorption.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] Not applicable.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not applicable.
THE NAMES OF THE PARTIES TO A JOINT RESEARCH AGREEMENT
[0003] Not applicable.
INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISC
[0004] Not applicable.
REFERENCE TO A “MICROFICHE APPENDIX”
[0005] Not applicable.
BACKGROUND OF THE INVENTION
[0006] 1. Field of the Present Disclosure
[0007] This disclosure relates generally to heating systems for living and working spaces and more particularly to a hydronic floor heating system adaptable to a wide range of circuit configurations.
[0008] 2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 1.98
[0009] Williams, U.S. Pat. No. 3,037,746 discloses a floor covering for radiant heating installations, utilizing tiles for installation against a flat surface such as a floor, wall, ceiling, etc. for covering a heating element overlying that surface. The objectives of this invention can be obtained by positioning an elongated heating element on the surface in a sinuous pattern and covering it with relatively large tiles, preferably molded of plastic material, these tiles being grooved to receive sections of the sinuous heating element. One of the important features of the invention is to provide a tile which is so grooved that it can be used to cover both straight runs and curved end sections of a sinuous heating element.
[0010] Bourne, U.S. Pat. No. 4,782,889 discloses a low mass hydronic radiant floor heating system for heating a room by circulating a liquid, the system including a metal deck having a plurality of regularly spaced troughs to provide structural strength. The deck is adapted to be secured directly to a plurality of floor joists. Tubing is placed in the troughs to distribute heat by circulating warm liquid through the tubing. The troughs of the metal deck support structural floor loads while providing a housing for the tubing. Flat portions of the deck between the troughs distribute heat laterally.
[0011] Shiroki, U.S. Pat. No. 4,865,120 discloses a floor structure for heating a timber-framed house, with which the floor of the house can be kept warm for a while even after the circulation of hot water in the hot water pipe has been stopped, whereas the pipe can be reduced in length as well. In achieving an object as above, a floor structure for heating according to the present invention comprises: a wooden board; a wooden frame secured on the wooden board; a heat accumulating layer which is inserted and fitted inside the frame on the wooden board; a plurality of grooves extending from one edge of the wooden frame by way of the surface of the heat accumulating layer to the other edge relative to the one end thereof; and a metal plate which is inserted in these grooves, covers the surface of the heat accumulating layer and its contiguous surface of the wooden frame, and is fitted on the wooden frame.
[0012] Fiedrich, U.S. Pat. No. 5,292,065 and U.S. Pat. No. 5,579,996 disclose a hydronic heating system that has a boiler supplying hot supply water, a reservoir of cooler return water, a supply water line, a return water line and one or more heating loops through which water flows from the supply line to the return line, the heating loops including a heating element that is a length of tubing that conducts water from the supply to the return and is mounted in a wall or a floor of an area heated by said system by RFH or RWH has: a thermally conductive plate mounted in the area floor or wall, adjacent a surface thereof and board-like members for holding the plate and the length of tubing in intimate thermal contact with the plate, so that the plate is heated by conduction of heat from the tubing and the plate has a radiating surface that radiates heat to the area. The plate and board-like members with an elongated space for holding the tubing is provided as a modular piece and several such modular pieces are arranged in line attached to the sub-flooring for RFH, or the wall studs for RWH, for insertion of the length of tubing in the aligned slots thereof; and following such insertion, the installation is ready for a finishing floor or wall covering. Thus, RFH or RWH is installed “dry” (without wet concrete, cement, or plaster) and can be accessed later by removing the finishing cover.
[0013] Pickard et al, U.S. Pat. No. 5,454,428 discloses an extruded aluminum radiant heat transfer plate including an integral elongated receptacle for holding and confining a plastic tubing. The aluminum radiant heat transfer plate is extruded to provide heat transfer side edges in the form of thin-walled fins running the length of the extrusion. Between the fins, the extrusion provides the elongated receptacle for the plastic tubing. The receptacle can take the form of a “C” that stands above the plane of the heat transfer fins. The receptacle, alternately, can take the form of a “U,” the legs of which integrally connect to the fins.
[0014] Alsberg, U.S. Pat. No. 5,788,152 discloses in combination, a radiant panel heating system, configured for ease of installation and maintenance which also provides the structural characteristics required of a sub-flooring panel within a floor framing system. The system consists of structural sub-flooring panels with grooves arrayed in a modular geometry. The panels are overlaid with a heat-conducting surface embossed with a matching groove pattern. The panels are capable of being fastened to a variety of floor support structures in a manner typical of sub-floor panels, which fulfill a structural requirement only while simultaneously interacting to create an array of approximately evenly spaced grooves into which tubing or wire of the type used in hydronic or electric radiant panel heating is installed.
[0015] Fiedrich, U.S. Pat. No. 5,931,381 discloses in radiant floor, wall and/or ceiling hydronic heating and/or cooling systems using metal radiation plates that are heated or cooled by attached tubing that is fed hot or cold water, where the system includes a plurality of aligned modular heating and/or cooling panels attached to the floor, wall and ceiling, each panel containing a metal radiation plate and each holds a length of the same tubing, the tubing being inserted into an accommodation in the panel and held therein in intimate thermal contact with the plate, and the assembly of panels with tubing inserted is covered with a finished floor, wall or ceiling and then hot water for heating or cold water for cooling is fed to the tubing, a thermal barrier is provided between the panels and the finished floor, wall or ceiling to: diminish or eliminate “hot spots” in the surface of the finished flooring, wall covering and ceiling covering during heating and “cold spots” during cooling; avoid condensation during cooling; and improve performance.
[0016] Fiedrich, U.S. Pat. No. 6,270,016 discloses in a hydronic radiant heating and/or cooling system modular panels each of a metal plate or sheet on a board or boards providing a slot into which tubing is inserted and held against the plate in intimate thermal contact therewith, so that the plate is heated/cooled by conduction of heat between the water in the tubing and the plate, the improvement in which two or more of said panels are hinged together, side by side or end to end to provide a hinged set of panels so that two or more of sets of hinged panels unfolded at their hinges and arranged side by side on a floor, wall or ceiling provide elongated spaces into which said tubing is inserted and held against said radiation plate a finished floor, wall or ceiling covering can be installed thereon and said system operated to heat or cool said room.
[0017] Chiles et al, U.S. Pat. No. 6,726,115 discloses a radiant heating system for installation on a sub-floor. Header panels having arcuate cutouts are secured on the sub-floor near opposite walls of a room. Spaced apart sleepers are secured to extend between the header panels and provide channels that receive radiant heating tubing. The cutouts are initially occupied by break away header plates which can be detached to allow the tubing to curve through the cutouts so that it can extend between the ends of adjacent channels. The cutouts can be inserted back into the cutouts to secure the tubing bends in place. Heat conductive panels overlie the sleepers and channels and can be overlaid with finished flooring.
[0018] Rodin, U.S. Pat. No. 6,739,097 discloses a floor element, for floor heating systems and the like, and a method of manufacturing such element. The element includes a sheet having at least one channel and a heat transfer layer which extends over one main surface of the sheet and on each side of respective channels, and forms an upwardly open recess that receives a heat transfer conductor and tightly embraces the conductor around half its circumference in the channel, with the upper side of the conductor being flush with or lower than the upper side of the sheet. The heat transfer layer is preferably made of thin, readily flexed foil that has a thickness of less than 200 m.
[0019] Seki et al, U.S. Pat. No. 6,776,222 discloses a foldable floor heating panel that can be folded longitudinally and laterally. The foldable floor heating panel includes several small plate-like members of a rectangular plan configuration, which are arranged longitudinally and laterally so as to be adjacent to each other. A flexible thin plate is attached to upper surfaces of the small plate-like members so as to allow longitudinal and lateral folding. Heat carrier flexible tube passages are provided in longitudinal and lateral folding portions of the panel so as to leave some play, and folding margin members are provided at the lateral folding portions. Fit-in members are attachably and detachably provided in respective heat carrier flexible tube passages with some play.
[0020] The related art described above discloses foldable floor heating panels, grooves for heating devices, use of a metal sheet conductive layer, cemented mounting of tubes, and headers for tube transfer. However, the prior art fails to disclose the use of a plurality of elongated panels each foldable for stacking in an accordion style. Additionally, the prior art teaches floor heating systems which conduct hot water through a single series circuit of tubing. It fails, however, to teach a system with the capability to selectively conduct a range of circuit configurations including both series and parallel circuits. The present disclosure distinguishes over the prior art providing heretofore unknown advantages as described in the following summary.
BRIEF SUMMARY OF THE INVENTION
[0021] This disclosure teaches certain benefits in construction and use which give rise to the objectives described below.
[0022] Hydronic floor heating is a well-known technique of heating living and working spaces. However, as mentioned above, much of the prior art discloses heating panels which tend to be difficult to store and transport due to their size. This, in turn, can make storage, transportation, and installation rather expensive. The presently described apparatus provides a solution to this problem by enabling the heating panels to fold in a compact accordion fashion for storage and transport.
[0023] In addition, the prior art teaches heating systems which conducts hot water through tubing in a series circuit. This obviously leads to gradual cooling of the water as it travels through the tubing, thus creating a thermal gradient across the floor. The presently described apparatus provides a solution to this problem, creating faster and more uniform heat dispersal, by enabling the tubing to be run in both series and parallel circuits and with a circuit density as desired.
[0024] The present invention uses flat foldable heating panels that are placed in adjacency and fastened over a supporting sub-floor. These heating panels receive conducting tubes for the transfer of heating fluids, and transition panels provide selective configuration of the fluid flow between panels. The heating panels are segmented for folding in a stacked arrangement for easy transport and installation.
[0025] A primary objective inherent in the above described apparatus and method of use is to provide advantages not taught by the prior art.
[0026] A further objective is to provide such a floor heating system that provides a choice of water flow path arrangements.
[0027] A still further objective is to provide a hydronic floor heating system that is easily transported.
[0028] A still further objective is to provide such a floor heating system that is compactly stored when not installed.
[0029] An even further objective is to provide such a floor heating system for which installation is relatively easy and inexpensive.
[0030] Other features and advantages of the present invention will become apparent from the following more detailed description, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the presently described apparatus and method of its use.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)
[0031] Illustrated in the accompanying drawing(s) is at least one of the best mode embodiments of the present invention In such drawing(s):
[0032] FIG. 1 is a perspective view of portions of panels of the present invention as installed on a sub-floor of a room;
[0033] FIG. 2 is a perspective view of a heating panel thereof having panel segments arranged in a co-planar orientation;
[0034] FIG. 3 is an end view thereof with the panel segments shown in a partially folded state;
[0035] FIG. 4 is a top plan view of a portion of a transition panel thereof abutting an end of a heating panel;
[0036] FIG. 5 is a partial perspective view thereof showing a metal sheet being placed onto a panel segment; and
[0037] FIGS. 6 through 9 are partial perspective views depicting stages of installation including respectively: laying heating panels, fastening the panels to the sub-floor, fastening tubing to the metal sheets, and covering the panels and metal sheets with a sound insulation and heat conduction padding.
DETAILED DESCRIPTION OF THE INVENTION
[0038] The above described drawing figures illustrate the described apparatus and its method of use in at least one of its preferred, best mode embodiment, which is further defined in detail in the following description. Those having ordinary skill in the art may be able to make alterations and modifications to what is described herein without departing from its spirit and scope. Therefore, it must be understood that what is illustrated is set forth only for the purposes of example and that it should not be taken as a limitation in the scope of the present apparatus and method of use.
[0039] Described now in detail, and illustrated in the figures, is a preferred embodiment of the present invention, a hydronic floor heating apparatus adaptable to various installation sizes and fluid conducting circuit arrangements as a system. The apparatus is modular comprising a plurality of heating and transition panels and fluid conductors. Heating panels 2 ( FIG. 2 ) are each made up of a plurality of panel segments, referred to herein as planks 4 . Each plank 4 contains a linear groove 8 extending medially and longitudinally between opposing ends 10 of the plank 4 on its mounting surface 12 . Additionally, each plank 4 has a continuous metal sheet 14 covering the mounting surface 12 ( FIG. 5 ) and also fastened into the respective linear groove 8 . The planks 4 are positioned in side-by-side juxtaposition and joined by a hinge 6 , which may be plural individual hinges 6 or one continuous hinge 6 and may be made of cloth, duct tape, or other similar materials which will be known to those of skill in the art. The hinges 6 are positioned on alternate sides of planks 4 enabling the side-by-side planks 4 to fold in accordion fashion between a coplanar arrangement, shown in FIG. 2 , and a stacked arrangement where the planks 4 are folded in the manner shown in FIG. 3 so that they lay face-to-face, i.e., with mounting surfaces 12 touching.
[0040] A transition panel 30 abuts each of the ends 10 of the heating panel 2 , and each panel 30 provides a first set of curved grooves 32 extending between the linear grooves 8 of adjacent pairs of the planks 4 , and a second set of curved grooves 34 extending between the linear grooves 8 of non-adjacent pairs of the planks 4 ( FIG. 4 ). In addition, a further linear groove 36 connects the second set of curved grooves, allowing for even more water flow path arrangements.
[0041] Preferably, each heating panel 2 is rectangular in shape when in the unfolded state ( FIG. 2 ), and is made up of six of the planks 4 , preferably measuring 40 inches wide by 48 inches long; however, more or less planks 4 , as well as other sizes and shapes may be used without a loss of efficacy of the invention. Each plank 4 is preferably made of construction grade plywood so that it has flat surfaces and is dimensionally stable. Therefore, the planks 4 expand or contract minimally with temperature changes. Of course, other structural materials with similar engineering characteristics may be substituted in this application.
[0042] As demonstrated in FIG. 5 , the metal sheet 14 is mounted on the mounting surface 12 , preferably using a glue or similar bonding agent, and extends longitudinally between ends 10 . Each metal sheet 14 has a sheet upset 16 , preferably a rectangular notch, which fits intimately within the linear groove 8 when the metal sheet 14 is mounted on plank 4 . The metal sheets 14 are preferably made of a good thermal conductor such as aluminum. Use of aluminum sheets enables the apparatus to efficiently disperse and transfer heat away from the linear grooves 8 so that the metal sheets 14 maintain a uniform temperature across their full width and length without appreciable thermal gradients even when warming up or cooling down.
[0043] Tubing 20 is mounted with a bonding agent 44 within selected ones of upsets 16 and grooves 32 , 34 , 36 as desired. The upsets 16 and grooves 32 , 34 , 36 are deep enough to secure tubing 20 below the respective outer surfaces. The tubing 20 is preferably made of cross-linked polyethylene material, which allows it to maintain its required flexibility and strength over a range of temperatures that might be experienced at the installation site. Other tubing materials may be substituted depending on particular environmental situations.
[0044] As shown in FIG. 1 , when installing the present apparatus, a pair of transition panels 30 is used, abutting the ends of each heating panel 2 . The purpose of these transition panels 30 , shown in greater detail in FIG. 4 , is to allow for a variety of placement patterns for tubing 20 during installation. For example, tubing 20 may be placed within each one of the sheet upsets 16 . In an alternative arrangement, tubing 20 may be placed within every other upset 16 , thus leaving some of the upsets 16 without tubing 20 . In addition, a first path of tubing 20 may be placed within alternating upsets 16 utilizing the first set of curved grooves 32 , while a second path of tubing 20 is placed within the other upsets 16 utilizing the second set of curved grooves 34 and the further linear groove 36 . Thus, the transition panels 30 allow for a variety of desired installation patterns, including both series and parallel circuits, which the installer can choose on site without additional modifications. Enabling the apparatus to run parallel circuits of hot water creates a more uniform dispersal of heat, thus avoiding the potential problem of water gradually cooling in a series circuit which might, create thermal gradients in the space being heated. While the preferred embodiment of each transition panel 30 includes a first 32 second 34 set of curved grooves, and a further linear groove 36 , clearly, it may have any plurality of sets of curved grooves and linear grooves.
[0045] Parquet and, in particular, laminate floors are sensitive to humidity. In addition, damp proofing is necessary in new buildings and cellars, and also in the case of repaired screeds in refurbished buildings. As shown in FIG. 6 , the heating panel 2 is being laid over the sub-floor 40 . The sub-floor 40 should have already been made moisture-proof with a layer of Polyethylene (PE) foil or similar water-proofing materials which will be known to those of skill in the art, as required by local building law and regulation. A layer of moisture and heat insulation padding is recommended to be laid on top of the PE foil to prevent downward heat transmission to the layers below. On top of the heating panels 2 , a heat conduction and sound proofing padding 24 is laid. This improves heat transmission to the flooring on top, and provides better impact absorption and sound insulation. Other material will be known to persons with ordinary skill in the art and may be substituted.
[0046] The method of installation of the present apparatus is quick and simple. After the accordion stacked planks 4 are moved into the room, they are unfolded to form the planar heating panels 2 . The panels 2 are then placed onto the prepared sub-floor 40 of the room. A plurality of heating panels 2 are used, as necessary, in order to cover the entire sub-floor 40 of the room, as illustrated in FIG. 1 . This is accomplished by placing the heating panels 2 in an abutting coplanar arrangement, side-by-side and end-to-end with the linear grooves 8 oriented in parallel and collinear as shown ( FIG. 6 ).
[0047] Transition panels 30 are then positioned, abutting the ends of each of the heating panels 2 . The transition panels 30 are positioned as shown in FIG. 4 , enabling the transition of the tubing 20 between the upsets 16 and the corresponding curved grooves 32 , 34 , 36 .
[0048] Next, each of the heating panels 2 and transition panels 30 are secured to the sub-floor 40 using fasteners 42 , such as screws or similar hardware, as shown in FIG. 7 . Tubing 20 is then engaged within selected ones of the upsets 16 and grooves 32 , 34 , 36 , as desired by the installer, to create a continuous path, or plurality of continuous paths, allowing fluids to flow through the panels. The tubing 20 is permanently secured using an appropriate bonding agent 44 , as shown in FIG. 8 .
[0049] Finally, a sound insulation and heat conduction padding 24 is placed over the heating panel 2 , as shown in FIG. 9 . Wood, vinyl, or laminated flooring may now be installed on top. For carpeted flooring, plywood backer sheet may be placed on top of the padding 24 . For tile flooring, thin liquid cement may be layered directly on top of the heating panel 2 . The tubing ends are connected to a hot water source, and pump if necessary, thus enabling hot water to travel through the floor continuously in order to heat the room.
[0050] The enablements described in detail above are considered novel over the prior art of record and are considered critical to the operation of at least one aspect of the apparatus and its method of use and to the achievement of the above described objectives. The words used in this specification to describe the instant embodiments are to be understood not only in the sense of their commonly defined meanings, but to include by special definition in this specification: structure, material or acts beyond the scope of the commonly defined meanings. Thus if an element can be understood in the context of this specification as including more than one meaning, then its use must be understood as being generic to all possible meanings supported by the specification and by the word or words describing the element.
[0051] The definitions of the words or drawing elements described herein are meant to include not only the combination of elements which are literally set forth, but all equivalent structure, material or acts for performing substantially the same function in substantially the same way to obtain substantially the same result. In this sense it is therefore contemplated that an equivalent substitution of two or more elements may be made for any one of the elements described and its various embodiments or that a single element may be substituted for two or more elements in a claim.
[0052] Changes from the claimed subject matter as viewed by a person with ordinary skill in the art, now known or later devised, are expressly contemplated as being equivalents within the scope intended and its various embodiments. Therefore, obvious substitutions now or later known to one with ordinary skill in the art are defined to be within the scope of the defined elements. This disclosure is thus meant to be understood to include what is specifically illustrated and described above, what is conceptually equivalent, what can be obviously substituted, and also what incorporates the essential ideas.
[0053] The scope of this description is to be interpreted only in conjunction with the appended claims and it is made clear, here, that each named inventor believes that the claimed subject matter is what is intended to be patented.
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A room heating apparatus uses separate heating panels fastened to a sub-floor to conduct a heating fluid which then adjusts the temperature of a room. The panels carry fluid tubing and transition panels conduct this tubing between the heating panels. The transition panels have a plurality of grooves that allow the selection of how the tubing is conducted between the heating panels so that a custom heating circuit may be formed to optimize the heating pattern of each installation.
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BACKGROUND OF THE INVENTION
This invention relates to a structure for reinforcing the telescopic front forks of a motorcycle or the like.
A motorcycle has a pair of telescopic front forks which suffer from a number of problems. The first problem is that the front forks are not completely sufficient in mechanical strength and rigidity. The second problem is that it is rather difficult to assemble and disassemble the front fork.
SUMMARY OF THE INVENTION
Accordingly, an object of this invention is to eliminate the above-described difficulties accompanying the conventional telescopic front forks of a motorcycle or the like.
More specifically, an object of the invention is to provide a front fork reinforcing structure for a motorcycle or the like which can improve the mechanical strength and rigidity of the pair of telescopic front forks thereof and which facilitates assembly and disassembly of the front forks.
The foregoing and other objects as well as the characteristic features of the invention will become more apparent from the following detailed description when read in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings:
FIG. 1 is a front view, partly as a sectional view, of one example of a front fork reinforcing structure according to this invention; and
FIG. 2 is an enlarged sectional view of the essential components of the front fork reinforcing structure of FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
One embodiment of this invention will now be described with reference to the accompanying drawings.
In FIG. 1 reference numeral 1 designates a pair of telescopic front forks each comprising a bottom case 2 and a fork pipe 3 which is axially slidably inserted into the bottom case 2. The fork pipes 2 are coupled to each other through a top bridge member 4. The fork pipes 2 are further coupled to each other through a bottom bridge member 5 provided below the top bridge member 4. A handle shaft (not shown) is fixedly secured to the midpoints of the bridge members 4 and 5 and is pivotally mounted on a head pipe (not shown). Handles 6 are fixedly secured to the upper end portions of the fork pipes 3, respectively, in such a manner that the handles 6 are in contact with the top bridge member 4.
Both end portions of a front wheel axle 7 are fixedly secured to the lower end portions of the bottom cases 2. A front wheel 8 is rotatably mounted on the front wheel axle 7.
Brackets 9 extend from the upper end portions of the bottom cases 2, respectively, in such a manner that the brackets extend towards each other as shown in FIG. 1. A connecting member 11 is formed so that the lower surfaces 12 of both end portions of the connecting member 11 are in close contact with the upper surfaces 10 of the brackets 9, respectively, when the connecting member 11 is secured to the brackets 9 with bolts 14. Each bracket has two female-threaded holes 13 as shown in FIG. 2, and each of the two end portions of the connecting member 11 has two through-holes 17. Accordingly, the connection member 11 can be detachably secured to the brackets at either end with the male-threaded portions 15 of the bolts 14 engaging the female-threaded holes 13 through the through-holes in the connecting member 11.
As is apparent from the above description, the pair of fork pipes 3 are coupled to each other through the top and bottom bridge members 4 and 5, and the brackets 9 extending from the upper end portions of the pair of bottom cases 2 are coupled to each other through the connecting member 11. Accordingly, the pair of telescopic front forks 1 are improved in mechanical strength and rigidity, and the handle shaft (not shown) and components related thereto are improved in torsional rigidity.
In the above-described embodiment, the connecting member 11 is tightened to the brackets 9 of the bottom cases 2 from above with the bolts 14. Therefore, the front forks 1 are maintained symmetrical.
As the connecting member 11 and the brackets 9 of the bottom cases 2 are made into one unit by the use of the bolts, assembly or disassembly of the front forks 1 can be readily achieved.
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The mechanical strength and torsional rigidity of the front forks of a motorcycle are improved by a connector rigidly joining brackets attached to the lower casings.
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TECHNICAL FIELD
This invention relates generally to freeze drying and, more particularly, to cold shelves employed to carry out freeze drying.
BACKGROUND ART
Freeze drying is a sublimation process that removes free water in the form of ice. Freeze drying is especially useful in the pharmaceutical industry to remove water from biological products because it preserves the integrity of the biological products. In freeze drying the water-containing product is frozen and, under vacuum with the partial pressure of water vapor reduced below the triple point of water, the frozen water sublimes and the sublimated ice is removed from the dryer.
It is important that the water-containing product be completely frozen prior to the drying steps. Moreover, because the water-containing product generally includes another solvent and/or soluble solids, the freezing point of the product, termed the lowest eutectic temperature, is generally much lower than the freezing point of water. For example, the lowest eutectic temperature of a sugar based biological product may be as low as -65° C. Accordingly, freeze drying requires the provision of significant refrigeration over a short period of time.
Heretofore, freeze drying has been carried out commercially using mechanical freezing systems. However, the refrigerant, such as for example a Freon, which is generally used with such mechanical devices has been deemed environmentally deleterious and is being eliminated from commercial use. Replacement refrigerants are not as thermodynamically effective making their use in the demanding application of freeze drying problematic. Moreover, replacement refrigerants for mechanical chillers are generally corrosive and toxic and require different compression ratios, making their use expensive from an operational standpoint. Moreover, an additional intermediate heat transfer fluid is needed and this has severe limitations on the temperature ranges that can be achieved.
It is known that a cryogenic fluid such as liquid or gaseous nitrogen is very cold and can deliver a significant quantity of refrigeration. However, cryogenic fluids have not heretofore been used to refrigerate the cold shelves of a freeze dryer. The cold shelf is the platform upon which the water-containing product is placed for freeze drying. It is important in carrying out freeze drying that the temperature be uniform over the entire cold shelf to ensure product quality. It is very difficult to control the release of refrigeration from a cryogenic fluid. It has heretofore been impractical to provide a near uniform temperature distribution across the entire cold shelf of a freeze dryer using a cryogenic fluid.
Accordingly, it is an object of this invention to provide a cold shelf for use in a freeze drying system wherein a cryogenic fluid may be used as the source of refrigeration and wherein a relatively uniform cold temperature may be provided over the entire cold shelf.
It is another object of this invention to provide a cold shelf for use in a freeze drying system wherein a cryogenic fluid may be used as the source of refrigeration thus eliminating the need for an intermediate heat transfer fluid and the concomitant limitations on the temperature ranges.
SUMMARY OF THE INVENTION
The above and other objects, which will become apparent to one skilled in the art upon a reading of this disclosure, are attained by the present invention, one aspect of which is:
A cryogenic cold shelf comprising spaced panels defining a shelf volume, and a cryogen distributor within said shelf volume in flow communication with a source of cryogenic fluid and capable of having cryogenic fluid flow therethrough, said cryogen distributor comprising a main flow path having a first leg and a second leg downstream of the first leg, said first leg having a plurality of first branches extending from the first leg, and said second leg having a plurality of second branches extending from said second leg and oriented between said first branches.
Another aspect of the invention is:
A cryogenic cold shelf comprising spaced panels defining a shelf volume, and a cryogen distributor within said shelf volume in flow communication with a source of cryogenic fluid and capable of having cryogenic fluid flow therethrough, said cryogen distributor comprising a main flow path having a cryogenic fluid input and having a length extending through the shelf volume, and having a plurality of branches communicating with the main flow path along its length, said branches having perforations for passing cryogenic fluid out from the cryogen distributor into the shelf volume, at least one branch positioned closer to the cryogenic fluid input having smaller perforations than at least one branch positioned further from the cryogenic fluid input.
As used herein, the term "cryogenic fluid" means a fluid having a temperature at or below -80° C.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a simplified schematic representation of one arrangement for providing cryogenic fluid for freeze drying which may be used in the practice of this invention.
FIG. 2 is a simplified plan view of one embodiment of the cryogenic cold shelf of this invention with the upper panel removed.
FIG. 3 is a simplified plan view of another embodiment of the cryogenic cold shelf of this invention with the upper panel removed.
FIG. 4 is a cross-sectional representation of a preferred joint which enables easier vertical movement of the cryogenic cold shelf of this invention.
DETAILED DESCRIPTION
The invention will be described in detail with reference to the Drawings and with the use of vaporized liquid nitrogen as the cryogenic fluid. Any effective cryogenic fluid may be used in the practice of this invention. The cryogenic fluid may be in the form of a liquid, a gas or a gas/liquid mixture. Among the components which may be used in the practice of this invention as or in the cryogenic fluid one can name, nitrogen, argon, oxygen, helium and air.
FIG. 1 illustrates in simplified form one overall arrangement for a freeze drying system employing cryogenic fluid. Referring now to FIG. 1, liquid nitrogen is provided in stream 1 into venturi 2. The venturi has a compression cone and an expansion cone. When the pressurized cryogenic fluid passes through, it will entrain low pressure spent nitrogen gas 15 at the center of the venturi. Thus, if desired, part of the spent nitrogen gas 9 can be recycled to mix or vaporize part of the incoming cryogenic fluid 1.
Liquid nitrogen 3 is withdrawn from venturi 2 and is combined with warm nitrogen gas in stream 4 to form stream 5 which is mixed in in-line mixer 6. The mixing action in in-line mixer 6 causes the liquid nitrogen to vaporize and to form cryogenic gas which is passed in line 7 into freeze dryer 8. The freeze dryer has a plurality of vertically oriented cold shelves upon which the water-containing product is placed for freeze drying. After the cryogenic gas is employed in the cold shelves for freeze drying, it is withdrawn from the cold shelves of the freeze dryer as shown by line 9. The spent nitrogen gas is split into three portions. A portion 10 of the spent nitrogen gas in line 9 is withdrawn from the system. Another portion 11 is passed into venturi 12 into which is also passed additional liquid nitrogen in stream 13. Nitrogen fluid is withdrawn from venture 12 in stream 14. Normally condenser 16 is operating at 10° C. colder than are the cold shelves of freeze dryer 8. Stream 14 can be used directly in condenser 16. A third portion 15 of stream 9 is passed into venturi 2 as described earlier and is employed to form the aforesaid stream 3. If needed, nitrogen gas in stream 19 is warmed by passage through heater 20 to form stream 4 which is mixed with stream 3 as was previously described.
During the cooling and freezing cycles very little heat is required from heater 20. A temperature programmer measuring the temperatures in the freeze dryer will provide heat into stream 19. When the water-containing product is fully frozen and the vacuum cycle has started, the temperature programmer will gradually increase heat load to heater 20. A second temperature program may gradually increase the temperature of cryogenic fluid 1 or mix in room temperature nitrogen gas. At the end of the cycle stream 7 can reach as high as 60° C. while stream 1 may be supplying room temperature nitrogen gas. Cryogenic fluid 13 maintains the cold temperature until the stoppers have closed the water-containing products.
FIG. 2 illustrates in plan view a cryogenic cold shelf of this invention as may be used in a freeze dryer such as freeze dryer 8 illustrated in FIG. 1. Referring now to FIG. 2, cold shelf 25 comprises spaced panels which define a shelf volume therebetween. In the representation of FIG. 2, the upper panel of cold shelf 25 is not shown in order to illustrate the cryogen distributor. The lower panel of cold shelf 25 is illustrated as panel 26.
Within the shelf volume of cold shelf 25 there is positioned cryogen distributor 27 which is in flow communication with a source of cryogenic fluid 28, e.g. line 7 of the system illustrated in FIG. 1. Cryogenic distributor 27 is capable of having cryogenic fluid flow therethrough. Typically cryogen distributor 27 comprises tubing having an inside diameter within the range of 0.125 to 3 inches.
Cryogen distributor 27 comprises a main flow path and branching flow paths. The main flow path comprises a first portion or first leg 29 and a second portion or second leg 30 downstream of the first leg. First leg 29 has a plurality of first branches 31 extending from the first leg preferably at a 90° angle, and second leg 30 has a plurality of second branches 32 extending from the second leg preferably at a 90° angle. At least one of the second branches 32 is oriented between first branches 31. The first branches 31 extending from first leg 29 receive slightly more cryogenic fluid than the second branches 32 extending from downstream second leg 30 due to pressure drop through the main flow path of cryogen distributor 27. In this manner, for example, the branch 33 which, in flow terms, is closest to the cryogenic fluid input 28 and has the highest cryogenic fluid flow rate therethrough, is matched up with branch 34 which, in flow terms, is farthest from input 28 and thus has the least cryogenic fluid flowing therethrough. As a result, a uniform distribution of cryogenic fluid is achieved throughout the cold shelf volume.
The first and second branches are perforated, the perforations having a diameter generally within the range of from 1/64 to 1/4 inch. The cryogenic fluid passes out from the perforations of the first and second branches and into the cold shelf volume wherein it serves to pass refrigeration into the upper and lower panels and from there to the water-containing products for freeze drying. Because of the uniform distribution of the cryogenic fluid through the cold shelf volume, the temperature is uniform over the entire area of the cold shelf. Spent cryogenic fluid is withdrawn from the cold shelf volume through exit conduit 35 which, for example, corresponds to line 9 of the arrangement illustrated in FIG. 1.
In the embodiment of the invention illustrated in FIG. 2 the first leg of the main flow path is positioned in the central area of the cold shelf volume and the second leg of the main flow path is positioned in a peripheral area of the cold shelf volume. Those skilled in the art will appreciate that other arrangements will also be effective. For example, the first leg could be positioned in one peripheral area with the second leg positioned in another peripheral area. In another arrangement both the first leg and the second leg could be positioned in the central area of the cold shelf volume.
FIG. 3 illustrates another embodiment of the invention. The cold shelf 45 illustrated in FIG. 3 is in some ways similar to that illustrated in FIG. 2 and these common features, i.e. the upper and lower panels, the shelf volume, the tubing size, and the communication with a source of cryogenic fluid, will not be described again in detail.
Referring now to FIG. 3, cryogen distributor 46 comprises main flow path 47 and branches 48 extending out along the length of the main flow path. Preferably main flow path 47 extends through substantially the entire length of the cold shelf volume. At one end of the main flow path there is cryogenic fluid input 49 for receiving cryogenic fluid into the cryogen distributor. The branches positioned closer to cryogenic fluid input 49, e.g. branches 50, have perforations which are smaller than the perforations which are in the branches, e.g. branches 51, which are further from cryogenic fluid input 49. In this way cryogenic fluid flows into the shelf volume through the branches further from input 49 at about the same flow rate as does cryogenic fluid flowing into the shelf volume through the branches closer to input 49 despite the pressure drop experienced along the length of main flow path 47. Typically the perforations in the further branches such as branches 51 will have an average diameter within the range of from 1/48 to 1/4 inch and the perforations in the closer branches such as branches 50 will have an average diameter within the range of from 1/64 to 1/5 inch. In this way the refrigeration provided to the cold shelf by the cryogenic fluid is evenly distributed over the entire surface of the cold shelf thus achieving similar benefits as with the embodiment of the invention illustrated in FIG. 2.
Spent cryogenic fluid may be withdrawn from the shelf volume of cold shelf 45 in the same manner as was illustrated in connection with shelf 25. FIG. 3 illustrates a preferred system for withdrawing spent cryogenic fluid from the shelf volume wherein the spent fluid is uniformly withdrawn from the shelf volume thus further avoiding the creation of any temperature gradient over the area of the cold shelf. Referring back now to FIG. 3, withdrawal line 52 has a length extending through cold shelf 45 with a plurality of branches 53 extending outward along its length and a fluid exhaust 54 at one end of its length. The branches further from exhaust 54, e.g. branch 55, have larger perforations similar to those of branches 51, than do the branches closer to exhaust 54, e.g. branch 56, which have perforations similar to those of branches 50. The spent fluid withdrawn through exhaust 54 may then be passed out of the freeze dryer such as is indicated by line 9 in FIG. 1.
In freeze drying it may be desirable to move the vertically stacked cryogenic cold shelves up or down in order to stopper or otherwise process flasks or other containers containing the product. The cold shelves may be pressed together without damaging the cryogenic fluid piping using the joint illustrated in FIG. 4. Referring now to FIG. 4, cryogenic fluid is provided to the cryogen distributor by means of Cryogenic transfer pipe 65 and cryogenic tube 66 which is movable therein. Cryogenic tube 66 has vacuum insulation 67 along its length and, at the interconnection of cryogenic tube 66 with cryogenic transfer pipe 65 there is joint 68 which comprises packing gland 69 made of fluorocarbon, graphite or other low temperature packing materials, and gas heating gland 70, both held in place by packing nut 71. The packing gland keeps the cryogenic fluid from leaking and entering the vacuum chamber of the freeze dryer. A warm gas is circulated inside gas heating gland 70 as shown by gas input 72 and gas output 73 to keep the packing material above its glass transition or embrittlement temperatures. The length of the packing gland and of the gas heating gland will depend upon the vertical traveling distance of the cryogenic cold shelves. The joint illustrated in FIG. 4 will enable the cryogenic cold shelf of this invention to easily move vertically with the rigid cryogenic transfer pipe attached, thus further enhancing the utility of the invention. If no shelf movement is required prior to the shelf being warmed to room temperatures, the joint illustrated in FIG. 4 is not necessary and flexible cryogenic hose for the connection is sufficient.
Although the invention has been described in detail with reference to certain preferred embodiments, those skilled in the art will recognize that there are other embodiments of the invention within the spirit and the scope of the claims.
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A cryogenic cold shelf for use in a freeze drying system having a cryogen distributor for passing cryogenic fluid into the shelf volume of the cold shelf at differing rates so as to even refrigeration provided over the entire shelf resulting in a uniform temperature over the cold shelf.
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RELATED APPLICATION DATA
The instant application is a continuation of U.S. Non-Provisional application Ser. No. 12/221,173 filed Jul. 31, 2008, now abandoned, which is a divisional of U.S. Non-Provisional application Ser. No. 11/704,614 filed Feb. 9, 2007, now issued as U.S. Pat. No. 7,410,327, which is a continuation of U.S. Non-Provisional application Ser. No. 10/820,597 filed Apr. 8, 2004, now abandoned, which claims the benefit of prior Provisional Application No. 60/461,602, filed Apr. 8, 2003.
FIELD OF THE INVENTION
The present invention relates generally to the field of oil and gas drilling and production. In a specific, non-limiting embodiment, the invention comprises a system and method of drilling oil and gas wells in arctic, inaccessible or environmentally sensitive locations without significantly disturbing an associated ground surface.
DESCRIPTION OF THE PRIOR ART
The drilling and maintenance of land oil and gas wells requires a designated area on which to dispose a drilling rig and associated support equipment. Drilling locations are accessed by a variety of means, for example, by roadway, waterway or another suitable access route. In particularly remote locations, access to a drilling site is sometimes achieved via airlift, either by helicopter, fixed wing aircraft, or both.
Some potential drilling and production sites are further constrained by special circumstances that make transportation of drilling equipment to the drilling site especially difficult. For example, oil and gas reserves may be disposed in locales having accumulations of surface and near-surface water, such as swamps, tidal flats, jungles, stranded lakes, tundra, muskegs, and permafrost regions. In the case of swamps, muskegs, and tidal flats, the ground is generally too soft to support trucks and other heavy equipment, and the water is generally too shallow for traditional equipment to be floated in. In the case of tundra and permafrost regions, heavy equipment can be supported only during the winter months.
Moreover, certain production sites are disposed in environmentally sensitive regions, where surface access by conventional transport vehicles can damage the terrain or affect wildlife breeding areas and migration paths. Such environmental problems are particularly acute in, for example, arctic tundra and permafrost regions. In these areas, road construction is frequently prohibited or limited to only temporary seasonal access.
For example, substantial oil and gas reserves exist in the far northern reaches of Canada and Alaska. However, drilling in such regions presents substantial engineering and environmental challenges. The current art of drilling onshore in arctic tundra is enabled by the use of special purpose vehicles, such as Rolligons™ and other low impact vehicles that can travel across the arctic tundra, and by ice roads that are built on frozen tundra to accommodate traditional transport vehicles. Ice roads are built by spraying water on a frozen surface at very cold temperatures, and are usually about 35 feet wide and 6 inches thick. At strategic locations, the ice roads are made wider to allow for staging and turn around capabilities.
Land drilling in arctic regions is currently performed on ice pads, the dimensions of which are about 500 feet on a side; typically, the ice pads comprise 6-inch thick sheets of ice. The rig itself is built on a thicker ice pad, for example, a 6- to 12-inch thick pad. A reserve pit is typically constructed with about a two-foot thickness of ice, plus an ice berm, which provides at least two feet of freeboard space above the pit's contents. These reserve pits, sometimes referred to as ice-bermed drilling waste storage cells, typically have a volume capacity of about 45,000 cubic feet, suitable for accumulating and storing about 15,000 cubic feet of cuttings and effluent. In addition to the ice roads and the drilling pad, an arctic drilling location sometimes includes an airstrip, which is essentially a broad, extended ice road formed as described above.
Ice roads can run from a few miles to tens of miles or longer, depending upon the proximity or remoteness of the existing infrastructure. The fresh water needed for the ice to construct the roads and pads is usually obtained from lakes and ponds that are generally numerous in such regions. The construction of an ice road typically requires around 1,000,000 gallons of water per linear mile. Over the course of a winter season, another 200,000 gallons or so per mile are required to maintain the ice road. Therefore, for a ten-mile ice road, a total of 2,000,000 gallons of water would have to be picked up from nearby lakes and sprayed on the selected route to maintain the structural integrity of the ice road.
An airstrip requires about 2,000,000 gallons of water per mile to construct, and a single drill pad requires about 1,700,000 gallons. For drilling operations on a typical 30-day well, an additional 20,000 gallons per day are required, for a total of about 600,000 gallons for the well. A 75-man camp requires another 5,000 gallons per day, or 150,000 gallons per month, to support. Sometimes, there are two to four wells drilled from each pad, frequently with a geological side-track in each well, and thus even more water is required to maintain the site. Thus, for a winter drilling operation involving, for example, 7 wells, 75 miles of road, 7 drilling pads, an airstrip, a 75-man camp, and the drilling of 5 new wells plus re-entry of two wells left incomplete, the fresh water requirements are on the order of tens of millions of gallons.
Currently, arctic land exploration drilling operations are conducted only during the winter months. Roadwork typically commences in the beginning of January, simultaneous with location building and rig mobilization. Due to the lack of ice roads, initial mobilizations are done with special purpose vehicles that are suitable for use even in remote regions of the arctic tundra.
Drilling operations typically commence around the beginning of February, and last until the middle of April, at which time all equipment and waste-pit contents must be removed before the ice pads and roads melt. However, in the Alaskan North Slope, the tundra is closed to all traffic from May 15 to July 1 due to nesting birds. If the breakup is late, then drilling prospects can be fully tested before demobilizing the rig. Otherwise, the entire infrastructure has to be removed, and then rebuilt the following season.
From the foregoing, it is clear there are several drawbacks associated with current arctic drilling and production technology. For example, huge volumes of water are pumped out of ponds and lakes and then allowed to thaw out and become surface run-off again. Also, the ice roads can become contaminated with lubricant oil and grease, antifreeze, and rubber products. In addition to the environmental impact, the economic costs associated with arctic drilling can be prohibitively high. Exploration operations can be conducted only during the coldest times of the year, which typically lasts less than 4 or 5 months. Thus, using ice pads, actual drilling and testing can be conducted in a window of only two to four months or less, and actual production and development can occur during less than half the year. At the beginning of each drilling season, the ice roads and pads must all be rebuilt, and equipment must again be transported to and removed from the site, all at substantial financial and environmental cost. As for the commercial development of hydrocarbons in the arctic tundra, the current state of the art requires the use of a gravel pad for year round operations. When production activities are completed (for example, at the end of the lifecycle of the field), the gravel pads must be removed and the site remediated. Such remediation efforts can be very costly and difficult to accomplish.
SUMMARY OF THE INVENTION
According to one aspect of the invention, a method of constructing a drilling or production platform is provided, the method including: drilling a post hole into a ground surface; inserting a support post into said post hole, wherein said support post has an adjustable shoulder member; adding a fluid slurry to said post hole to freeze said support post within an interior region of said post hole; disposing a modular platform section on top of said adjustable shoulder member to establish a platform deck surface; and adjusting said adjustable shoulder member so that said platform deck surface is disposed substantially level.
According to a further aspect of the invention, a method of constructing a drilling or production platform is provided, the method including: drilling or hammering a support post into a ground surface, wherein said support post further comprises an adjustable shoulder member; disposing a modular platform section on top of said adjustable shoulder member to establish a platform deck surface; and adjusting said adjustable shoulder member so that said platform deck surface is disposed substantially level.
According to a further aspect of the invention, a method of constructing a platform suitable for drilling and producing oil, gas and hydrate reserves is provided, the method including: disposing a platform section atop a plurality of support posts; disposing two substantially parallel support beam sections between two of said support posts; and disposing a deck section atop said two substantially parallel support beams to provide a bridging support means between said two substantially parallel beams.
According to a further aspect of the invention a method of constructing a drilling or production platform is provided, the method including: providing a first platform section supported by support posts, wherein each of said support posts are disposed proximate to the corners of said first platform section; providing a second platform section, wherein said second platform section further comprises a hooking member that hooks onto a first side of said first platform section; providing a plurality of support posts to support a side of said second platform section disposed opposite said first side of said second platform section; and providing a third platform section, wherein said third platform section further comprises a hooking member that hooks said second platform section.
According to a still further aspect of the invention, a method of assembling a plurality of interlocking modular platform sections useful for supporting drilling equipment on a deck surface is provided, the method including: disposing a first modular platform section and a second modular platform section atop a plurality of platform support posts; disposing a hook and hook receiving member proximate an interface formed between said first platform section and said second platform section, wherein said hook is disposed along a side portion of said first platform section, and said hook receiving member is disposed on a side portion of said second platform section, and thereby.
According to a still further aspect of the invention, a method of communicating utilities between a deck section and a platform section of a drilling or production platform is provided, the method including: disposing a deck section atop a platform section; disposing one or more holes in a top surface of said deck section to permit utility communication between an interior region of said deck section and a deck surface disposed atop said deck section; and disposing one or more holes between a lower surface of said deck section and an upper surface of said platform section.
According to a still further aspect of the invention, a method of heating a drilling or production platform support post is provided, the method including: disposing a fluid conduit through a body portion of said support post; disposing a hollow fluid transfer member around or near an outer surface of said support post, wherein said fluid conduit disposed in a body portion of said support post is in fluid communication with said hollow fluid transfer member; and drawing a cooling or warm fluid into said fluid conduit and passing said fluid through said hollow fluid transfer member.
According to a further aspect of the invention, a method of removing a drilling or production platform support post is provided, the method including: disposing a fluid conduit through a body portion of said support post; disposing a hollow fluid transfer member around or near an outer surface of said support post, wherein said fluid conduit is disposed in fluid communication with said hollow fluid transfer member; drawing a warm fluid into said fluid conduit and passing said fluid through said hollow fluid transfer member to heat the surrounding ground; and applying a pulling force to said support post to pull said support post from the ground.
According to a still further aspect of the invention, a method of removing a drilling or production platform support post is provided, the method including: disposing a fluid conduit through a body portion of said support post; disposing a hollow fluid transfer member around or near an outer surface of said support post, wherein said fluid conduit is in fluid communication with said hollow fluid transfer member; disposing a vent between said fluid conduit and a surrounding ground surface using jets or ports; drawing a fluid or gas into said fluid conduit and passing said fluid through said hollow fluid transfer member, through said vent and out to the surrounding ground surface; and applying a pulling force to said support post to pull said support post from the ground.
According to a still further aspect of the invention, a method of adjusting the height of a modular drilling or production platform section is provided, the method including: disposing a modular platform section atop an adjustable shoulder nut disposed on a support post, wherein a top portion of said support post further comprises a lift receiving means; disposing a lifting means proximate to said lift receiving means, and then mutually engaging said lifting means and said lift receiving means; lifting said modular platform section off of said adjustable shoulder nut and then supporting said modular platform section using a support means; raising said adjustable shoulder nut; and replacing said modular platform section atop said adjustable shoulder nut using said support means.
According to a still further aspect of the invention, a method of sealing an intersection formed between a plurality of interlocked platform modules, the method including: disposing four interlocked platform modules so that a four-way intersection is formed therebetween; disposing a sealing member over said four-way intersection, wherein said sealing member comprises a body member and a plurality of leg members; and augmenting the seal using a deformable sealing material.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a modular drilling or production platform according to the invention.
FIG. 2 is a section of a well bore included in the drilling or production platform shown in FIG. 1 , taken at a right angle along a length of the platform.
FIG. 3 is a section of a well bore included in the drilling or production platform shown in FIG. 1 , taken along a centerline of the platform.
FIG. 4 is a sectional view of a surface tundra region in which a plurality of post holes has been drilled.
FIG. 5 is the sectional view of FIG. 4 , further comprising a plurality of support posts disposed in the post holes.
FIG. 6 is the sectional view of FIG. 5 , further comprising a plurality of support posts having adjustable shoulders.
FIG. 7 is the sectional view of FIG. 6 , further comprising a group of interconnected modular platform sections disposed on top of the platform support posts.
FIG. 8 is the sectional view of FIG. 7 , further comprising a full level of interconnected modular platform sections disposed on top of the platform support posts.
FIG. 9 is the sectional view of FIG. 8 , further comprising a plurality of deck sections installed atop the modular platform sections.
FIG. 10 is the topmost portion of a support post, further comprising an adjustable nut disposed at the bottom of the adjustment stroke.
FIG. 11 is the topmost portion of a support post, further comprising an adjustable nut disposed at a position higher than the bottom of the adjustment stroke.
FIG. 12 is a group of interconnected modular platform sections, installed atop a plurality of platform support posts.
FIG. 13 is a cross-sectional view of the installed platform sections shown in FIG. 12 .
FIG. 14 is a top view of assembled modular platform sections according to the invention.
FIG. 15 is a cross-sectional view of the assembled platform sections of FIG. 14 .
FIG. 16 is a partial view of the assembled platform sections shown in FIG. 14 .
FIG. 17 is a top view of a group of interconnected modular platform sections.
FIG. 18 is a top view of a group of interconnected modular platform sections.
FIG. 19 is a cross-sectional view of the interconnected modular platform sections shown in FIG. 18 .
FIG. 20 depicts a connecting means useful for interconnecting a plurality of modular platform sections.
FIG. 21 is a top view of a group of modular platform sections that are interconnected using a connecting means according to the invention.
FIG. 22 is a depiction of an intersection established between four interconnected modular platform sections.
FIG. 23 is a view of the intersection of four interconnected modular platform sections shown in FIG. 22 , wherein the intersection is substantially sealed by a sealing means.
FIG. 24 a is a top view of an x-shaped sealing member useful for substantially sealing a gap formed at the intersection of a plurality of interconnected modular platform sections.
FIG. 24 b is a side view of the x-shaped sealing member shown in FIG. 24 a.
FIG. 25 is a sectional view of a fluid waste retention member disposed on an outer perimeter portion of a modular platform section.
FIGS. 26 a and 26 b are plan views of a fence sealing member that has been clipped onto a portion of a fluid retention fence using a clip tab.
FIGS. 27 a and 27 b are plan views of a retaining fence gap sealing member equipped with a seal extension member.
FIGS. 28 a and 28 b are plan views of a fence corner seal, in which the corner seal is bridging a gap formed between corner sections of a fluid retention fence.
FIG. 29 is a top view of a group of assembled modular deck sections following installation atop a plurality of associated platform sections.
FIG. 30 is a cross-sectional view of the platform shown in FIG. 29 .
FIG. 31 is a cross-sectional view of the platform shown in FIG. 29 .
FIG. 32 is a cross-sectional view of a support post disposed in a post hole.
FIG. 33 is a cross-sectional view of an upper end of the support post shown in FIG. 32 .
FIG. 34 is a detailed view of a lower end of the support post shown in FIG. 32 .
FIG. 35 is a platform and deck assembly supported by a support leg, wherein a jacking assembly is disposed above a lift socket located on a topmost portion of the support leg.
FIG. 36 is the platform and deck assembly shown in FIG. 35 , wherein a hydraulic cylinder is extended down from the jacking assembly until contact with the support post is established.
FIG. 37 is the platform and deck assembly shown in FIG. 35 , wherein a jacking assembly has lifted the platform and deck assembly off an adjustable nut disposed on the support post.
FIG. 38 is the platform and deck assembly of FIG. 35 , wherein the adjustable nut has been raised to again support the weight of the lifted platform and deck assembly.
FIG. 39 is the platform and deck assembly of FIG. 35 , shown after the jacking assembly has been removed and adjustment of the platform height has been completed.
FIG. 40 is a jacking assembly installed beneath a platform and deck assembly so that the platform can be lifted from the bottom.
FIG. 41 is a cross-sectional view of a support post, wherein a wedge section is disposed on a tapered shoulder portion of an adjustable nut.
FIG. 42 is a top view of the support post head shown in FIG. 41 .
FIG. 43 is a partial rotational view of the support post head shown in FIG. 41 .
FIG. 44 is a platform floor plan according to an example embodiment of the invention.
FIG. 45 is a platform building isolated from the example floor plan of FIG. 44 .
FIG. 46 is a platform section having a bladder tank disposed within.
FIG. 47 is a cross-sectional view of the platform section and bladder tank assembly shown in FIG. 46 .
FIG. 48 is a wellhead cellar suitable for use in an arctic platform system.
FIG. 49 is an alternative wellhead cellar suitable for use in an arctic platform system.
FIG. 50 is a cross-sectional view of the seals used to secure an inner and an outer skin of a wellhead cellar.
FIG. 51 is a post hole in which a platform support post is disposed.
FIG. 52 is an adaptor useful for adding an extension onto the bottom of a support post.
FIG. 53 is the adaptor of FIG. 52 , with an additional pipe section welded thereon.
FIG. 54 is a partial section of a bottom portion of the support post shown in FIG. 51 .
FIG. 55 is a partial section of a support post on which an extension has been added.
FIG. 56 is a post hole in which a platform support post is disposed.
FIG. 57 is the post hole of FIG. 56 after the support post has been removed.
DETAILED DESCRIPTION
Referring now to a specific, though non-limiting, embodiment of the invention shown in FIG. 1 , a tundra region 1 is shown in which a number of support posts 2 are disposed in a number of post holes drilled into the tundra. The support posts 2 support a substantially level drilling or production platform 4 comprised of numerous interconnected modular platform sections. In certain embodiments, a cylindrical (or other shape) winterizer 6 encloses and winterizes a drilling rig (not shown), and a number of easily transportable modular platform sections 8 are installed around the drilling rig. In some embodiments, for example, where drilling is carried out at very cold temperatures (e.g., in arctic tundra regions), the rig area is heated during drilling operations. In a particular embodiment in which the platform is used for hydrate production, the rig area is only heated to an intermediate temperature of about +10 degrees F., so that recovered hydrates will not thaw and can be preserved for analysis. In other embodiments, however, the rig area is cooled to permit more comfortable drilling conditions during warmer summer seasons.
According to an alternative embodiment, a crane 10 is positioned on a deck portion of platform 4 , and is sufficiently mobile to move around on the deck area so that the crane can be used to carry out a number of different lifting and support functions. For example, in one example embodiment, crane 10 is used to assist in the initial outfitting of the platform, and thereafter to move spools of drilling string and other drilling supplies around the platform during drilling and production operations. One or more cranes can also be fixed mounted at key points.
In other embodiments, a group of interconnected housing modules are assembled to provide living quarters for personnel working on the rig. In some embodiments, the housing platform employs a support post and platform module construction method similar to the platform described above, except that housing modules are disposed on the top of the platform deck instead of drilling modules.
Referring now to an example embodiment shown in FIG. 2 , an arctic platform is provided wherein a plurality of support posts 2 are inserted into a plurality of corresponding post holes 20 that have been drilled into the tundra. In one embodiment, support posts 2 are fixed in the post holes 20 by a process known as ad freeze, which comprises pouring a fluid slurry (for example, a slurry of water, sand and gravel) into the post holes 20 in order to fix the support posts 2 in place after the slurry freezes and hardens. In other embodiments, the support posts are drilled or hammered directly into the ground surface. In a further embodiment, a plurality of modular, interconnectible platform sections 4 are installed atop and supported by the support posts 2 after the support posts have been frozen in place; in still further embodiments, a plurality of drilling container sections 8 are then stacked on top of the platform sections 4 to permit convenient local storage of drilling bits and other equipment related to the drilling operation.
In the particular embodiment depicted in FIG. 2 , the well being drilled 22 is disposed beneath a wellhead cellar 24 that supports a wellhead 26 and blowout prevention stack 28 . In the depicted embodiment, a substructure housing member 30 is disposed above the blowout prevention stack 28 during drilling operations so that the wellhead and blowout stack are safely housed beneath the housing structure 30 . In certain other embodiments, however, drilling rig 32 is disposed above the substructure housing 30 so that drilling rig 32 is instead contained within a winterizer 6 .
Similar to the embodiment shown in FIG. 1 , drilling platform 4 is comprised of a plurality of interconnectible, modular platform sections 34 and associated deck sections 36 . In a presently preferred embodiment, drilling or production platform 4 comprises 8 platform sections in width, and is supported by 9 rows of evenly spaced support posts 2 frozen into corresponding post holes 20 drilled in the tundra.
Referring now to the example embodiment of FIG. 3 , a drilling platform 4 is shown in cross section through a centerline of the well bore, drawn along a length of drilling rig 32 . In some embodiments, wellhead cellar 24 is disposed in operative communication with a pair of long wellhead platform sections 40 and 42 . In the particular embodiment depicted in FIG. 3 , drilling platform 4 further comprises three rows of support posts 2 . According to a presently preferred embodiment, arctic drilling platform 4 further comprises about sixteen individual, interconnected platform modules, each of which are about 12.5 feet wide and about 50 feet long; the resulting drilling platform 4 is therefore substantially square, and measures about a 100 feet on each side. In the aforementioned embodiment, there are about twenty-seven support posts 2 , each of which supports the weight and alignment of various platform sections. In further embodiments, one or more additional support posts 2 are strategically installed to lend additional stability and load capacity to the system.
In other embodiments, additional wells 44 are drilled to serve as backup wellbores in the event the primary wellbore encounters technical problems such as a broken drill bit or a jammed drilling string. According to a further embodiment, additional wells 44 are used to drill an underground pipeline routed to a remote location so that production removed from the primary well can be pipelined to a remote location in coordination with the ongoing drilling operation. The ability to drill an underground pipeline is particularly useful in environmentally sensitive sites in that removal and transportation of oil, gas and/or hydrates reserves can all be carried out deep beneath the ground surface, thereby reducing disturbance of the surrounding tundra region. The additional wells 44 can also be used to establish a field size.
According to a method of practicing the invention shown in FIGS. 4-9 , a plurality of holes 50 are first drilled into a ground surface or frozen tundra region 1 . In some embodiments, post holes 50 are evenly spaced apart; however, in other embodiments, additional support posts are strategically installed to lend greater stability and structural rigidity to the platform system. In other embodiments, only a few post holes (or even a single hole) are drilled to receive the support posts of a smaller, stand-alone work module, for example, a nearby secondary well drilled to relieve or apply fluid pressure to the drilling operation.
According to the embodiment shown in FIG. 5 , a plurality of support posts 2 are then inserted into each of the post holes 50 , with lower portions of the posts being supported by a plurality of post hole ground surfaces 60 , and intermediate portions of the posts being supported by one or more support brackets 64 and 66 attached to provide a temporary surface fitting at the surface level 62 of tundra region 1 while the support posts are being frozen in place within the post holes. According to a further embodiment, once the support posts 2 have been fixed in drilled post holes 50 , a slurry comprised of water, sand and gravel mixture is poured into the hole and allowed to freeze. According to still further embodiments, adjustable support brackets 64 and 66 are inserted near the top of the hole during the slurry freezing process, so that the tops of the support posts 2 stay accurately aligned during the slurry freezing process. In the example embodiment of FIG. 5 , a plurality of adjustable shoulder nuts 70 , 72 and 74 are disposed near the tops of each of the support posts 2 ; in the depicted embodiment, the adjustable nuts are disposed at different elevations (as indicated by lines 76 , 78 and 80 ) due to localized inaccuracies in the depths of the post holes.
As seen in the example embodiment shown in FIG. 6 , adjustable shoulder nut 72 is then raised (for example, by threading the nut up the shaft of a complementary threading formed on a portion of the support post) up to the same elevation level as the other adjustable nuts 70 and 74 (as indicated by lines 80 , 82 and 84 ). In this manner, a level plane is formed to support the later installation of a drilling platform, although in other embodiments, portions of the drilling platform are assembled prior to the drilling of the post holes, and whole sections of previously assembled platform modules are installed on the legs, and then leveled using the adjustable nuts.
Those of ordinary skill in the art will appreciate that when various platform sections are of a common cross-sectional thickness, it is convenient to set each of the adjusting nuts at about the same height. However, in other embodiments it is beneficial to set the adjustable nuts at different predetermined heights rather than a common height, depending upon the actual structural requirements imposed by various operational environments, for example, to build up the pitch of a side of the platform disposed on a downward slope.
FIG. 7 shows the cross-sectional platform view of FIG. 6 , further comprising a pair of interconnected modular platform sections 92 and 94 installed over a plurality of adjustable shoulder nuts. In one example embodiment, four interconnected modular platform sections are installed over the shoulder nuts of four support posts, for example, the two platform sections 92 and 94 depicted herein and two additional modular sections (not shown) disposed directly behind sections 92 and 94 . When the installation of deck sections is complete, workers are provided with a level and secure platform surface from which to drill, and effluent and metal cuttings can be contained in the box-like lower body portions of the deck sections. In still further embodiments, a canvas tarp or the like is disposed beneath and around an outer perimeter of the deck sections, and serves as a skirt or trap to ensure that as much waste as possible is captured and recovered from the drilling site.
Referring now to the example embodiment of FIG. 8 , a full level of interconnected modular platform sections 100 - 105 is then installed over each of the adjustable shoulder nuts. According to one aspect of the invention, minor adjustments to the heights of the shoulder nuts are then effected in order to correct the level of the platform on an as-needed basis. According to various other embodiments, the leveling corrections can be effected when the individual deck sections are being installed, or after all or some of the sections have already been assembled and interlocked.
In the example embodiment of FIG. 9 , a plurality of modular storage sections 106 - 109 is then installed above at least a portion of the platform deck. In some embodiments, the various storage sections 106 - 109 are strategically arranged so as to conveniently contain the equipment and supplies required to drill and maintain a well, for example, drill string and associated casings, lubricants, power generators, etc.
According to the example embodiment shown in FIG. 10 , the upper portion 120 of a support post 2 further comprises an adjustable shoulder nut 124 disposed at the bottom of the adjustment stroke. In some embodiments, upper post portion 120 has a reduced cross section 122 , and an adjustable shoulder nut 124 . In further embodiments, adjustable shoulder nut 124 further comprises an internal threaded region 126 , and a tapered, upwardly facing shoulder member 128 .
According to one aspect of the invention, support posts 2 are installed with each of the adjustable shoulder nuts 124 set at the bottom of the adjustment stroke; in other embodiments, however, the adjustable shoulder nuts 124 are set at predetermined positions other than at the bottom of the stroke, or even in random positions, depending upon the particular operational requirements of the drilling environment. In other embodiments, a tapered section 134 is provided at the top of adjustable nut 124 to allow wedges or shims to be dropped inside a space formed when a module is placed onto a post, thereby lending lateral support to the post as well as vertical support. In still other embodiments, one or more fluid receiving fittings 130 are provided at the top of the support post for receiving and circulating a heating or cooling fluid within a body portion of the post, and a threaded receiving member 132 is provided for attachment of a lifting means. In alternative embodiments, receiving member 132 is not threaded, and instead comprises a slip-toothed fastening assembly; in still further embodiments, receiving member 132 comprises an inverted nut and bolt receiving assembly for receiving a lifting means that has been lowered from the deck surface disposed above.
According to further examples of the invention, FIG. 11 shows an adjustable nut that was initially set at a position higher than the bottom of the adjustment stroke, for example, near the middle of the adjustment stroke in order to build up a platform section disposed on a downward slope. In FIG. 11 , adjustable shoulder nut 124 has been threaded up the support post to a higher position as a method of setting an upper shoulder 126 of the adjustable nut at the same elevation as the shoulders on neighboring posts.
According to the example embodiment of FIG. 12 , a plurality of interconnected modular platform sections 50 is provided, each of which is installed atop a plurality of support posts. According to a further embodiment, the lengths of the platform sections are elongated relative to their widths; in a presently preferred embodiment, the lengths of the platform modules are elongated relative to their widths by a ratio of about 4:1. For example, in one particular embodiment, each platform section is about 12.5 feet wide and about 50 feet long. In the depicted embodiment, sixteen such platform sections are combined to provide a substantially square deck surface that is about 100 feet in both length and width.
According to a detailed embodiment, platform 52 is supported by twenty seven different support posts 54 , each of which engage various platform sections from beneath the platform. Along the left side of platform section 60 is a beam member 62 , which provides bridging support between support posts 64 and 66 . Along the right side of platform section 60 is another beam member 70 , which provides bridging support between support posts 72 and 74 . In one embodiment, the underside of platform section 80 is a flat plate and includes a plurality of stiffening members 82 ; in some embodiments, stiffening members 82 are not intended to be structural or load bearing members, and are instead designed to support an accumulation of liquids and effluent that usually develops on a drilling platform.
According to one example embodiment, an interlocking method of securing the platform modules to one another permits disposition of but a single support post at each platform intersection, and adjacent platform modules are all supported by that single post. Although the interior corners of each platform section are near to and supported by a single support post, the support post is not necessarily attached to each of the surrounding platform sections. In one embodiment, for example, platform sections are attached to the support posts in such a fashion as to provide greater support in the direction of a line between support post 64 and support post 66 ; in this embodiment, greater support would also be provided between support post 72 and support post 74 . In this configuration, however, only minimal support is provided in the direction from support post 64 to support post 72 , and from support post 66 to support post 74 , said minimal support deriving from the rigidity produced when adjoining portion of platform sections are interlocked rather than by attachment of the platform section to a support post.
According to an example embodiment depicted in FIG. 13 , a load placed anywhere on the individual deck sections will be supported initially by the deck surface 120 , which in turn transfers the weight load in the direction indicated by arrow 130 (see FIG. 12 ) toward beam sections 82 and 96 disposed beneath the deck. The weight of the load is then transmitted down the side beams in the direction of arrow 132 (see FIG. 12 ) toward the support posts, which in turn directs the weight into the surface of the tundra. According to a further embodiment, rectangular beam 82 is established by assembly of a plurality of interlocked platform modules disposed on a side 94 portion of platform section 80 ; likewise, opposed rectangular beam 96 is established by assembly of a plurality of interlocked platform modules disposed on another side 104 of platform section 80 .
On top areas 110 and 111 of beam sections 82 and 96 , a deck section 120 is installed and then locked into place. In one example embodiment, deck section 120 provides direct support for the various equipment and supply packages loaded on top of the deck. According to another embodiment, beam sections 82 and 96 provide support in the direction of the support posts 64 and 72 shown in FIG. 12 .
In a further embodiment, deck section 120 comprises a composite structure having a top plate 122 and a bottom plate 124 , separated by a foam mixture 126 disposed in an interior region established within the platform modules. In one particular embodiment, foam mixture 126 is a polyurethane foam mixture that not only stabilizes and supports the structural integrity of the top and bottom plates, but also provides a compressive strength sufficient to support heavy equipment loads placed on top of the deck surface 120 . According to a further embodiment, the polyurethane foam mixture 126 also dampens the loud noises and structural vibrations typically created during drilling operations.
Turning now to methods and means of interlocking the platform modules, FIGS. 14 and 15 show a plurality of assembled modular platform sections similar to the embodiments described in FIGS. 12 and 13 .
For example, the platform is supported by twenty-seven support posts 54 , which engage the various platform sections from underneath. Along the one side of platform section 60 is a beam member 62 that provides bridging support between support posts 64 and 66 . Along the other side of platform section 60 is another beam member 70 , which provides bridging support between support posts 72 and 74 . The bottom of platform section 80 is a flat plate and includes a plurality of stiffening members 82 , which are not intended to be structural or load bearing in nature other than having sufficient capacity to support an accumulation of fluids that build up during drilling operations.
A single support post is disposed at each platform intersection, and the adjacent platform modules are all supported by that single post. While each platform section corner is near to and supported by a support post, the support post is not necessarily disposed in that platform section; the corners of some of the platform sections are supported by only the interlocking connection members disposed therebetween.
According to the example interlocking platform connection system shown in FIG. 16 , a first platform section 60 is disposed adjacent to a second platform section 140 ; a first deck section 142 is installed over platform section 60 , and a second deck section 144 is installed over platform section 140 . According to certain embodiments, a fence member 152 projects upwardly from an upper surface 150 of platform section 60 . According to a further embodiment, upper surface 160 of platform section 140 has a hook 162 disposed over the fence member 152 . According to the example embodiment of FIG. 16 , hook 162 is formed structurally integral with platform section 160 , and provides support for the side of platform section 160 ; in other embodiments, however, hook 162 is not formed structurally integral with platform section 160 , and is instead mechanically affixed to the system to provide support for the side of platform section 160 .
According to the example embodiment of FIG. 17 , a first platform section 60 is logically supported by at least four different support posts 64 , 66 , 72 and 74 . According to a further embodiment, however, a second platform section 160 is supported by only two additional support posts 162 and 164 , while support on the opposite side is achieved by means of a hooking member 163 engaged over a portion of fence member 152 shown in FIG. 16 . According to a still further embodiment, platform section 170 is supported by only two additional support posts 172 and 174 , though platform section 170 also gains support from support posts 162 and 164 on the opposite side by means of the mentioned hook and fence member combination. According to a still further embodiment, additional platform sections 180 , 182 , 184 , 186 and 188 are successively installed, in each instance installation requiring only two additional support posts and an opposed, complementary hook and fence member combination to ensure a secure and reliable connection.
Similarly, platform section 190 employs two additional support posts 192 and 194 at the end of the platform section disposed furthest away from platform section 170 . However, platform section 190 gains additional support from attachment to support posts 164 and 174 , and also from a hook and fence member combination disposed at the end most proximate to platform section 170 . Consequently, platform section 200 requires only a single additional support post 202 , provided said support post is employed in combination with a hook and fence member support means at each of intersections 204 and 206 . Additional platform sections 210 , 212 , 214 , 216 , 218 and 220 will also require only a single additional support post each, again provided the configuration includes an appropriate hook and fence member combination on two of the sides disposed opposite the support post.
Turning now to other example methods and means for connecting platform sections together, FIGS. 18-21 again show a drilling platform comprised of a group 52 of platform sections that have been interconnected for support of equipment storage modules that will later be installed on top of various portions of the platform. As shown, the platform sections are supported by twenty-seven support posts 54 , which engage various platform sections from locations disposed beneath the platform. Those of ordinary skill in the art, however, will appreciate that any number of platform and deck sections can be assembled into a single unitary whole (or even several discrete modular platform units), and any number of support posts can be employed to support the structure, depending on the various field requirements imposed by actual operating environments. Those of ordinary skill in the art will also appreciate that by employing the example platform assembly methods described above, weight loads can be directed and distributed in virtually any direction along the platform, and additional interconnections between platform sections can be established to either support weight loads disposed on deck sections, or to otherwise lend stability and structural rigidity to the resulting platform system.
Referring now to the example embodiment of FIG. 22 , a support post 2 is shown disposed near an intersection 230 of four interconnected platform modules 232 , 234 , 236 and 238 . Moving out radially from intersection 230 , a plurality of connecting hooks 240 , 242 , 246 and 248 are disposed over complementary fence members 250 , 252 , 254 and 256 , so that the several associated platform sections are securely interconnected. The hook and fence member assemblies also serve to effectively seal the intersection 240 where the platform sections are joined, at least insofar as accumulated water and the like will easily pass from one platform section to another across body portions of the hook and fence locking assemblies.
Intersection 230 , however, is more problematic. For example, virtually any liquid can pass through the space formed at the center of the four-corner intersection, and then pass between platform sections and down onto the ground surface disposed below. According to one aspect of the invention, therefore, a sealing member is provided to close the space formed at intersection 230 , the seal generally being disposed on the top side portion of the intersection, although installation of the seal from the bottom side of the intersection 230 is also contemplated. The sealing member, which in this case is referred to as an x-seal because of its shape, extends in each of four directions at least as far as a series of sealing grooves 260 that have been cut into body portions of each of the associated fence members 250 , 252 , 254 and 256 .
For example, as seen in FIG. 23 , a platform sealing member 270 is dropped over a four-corner intersection where four assembled platform modules have been interconnected. The body of the seal is substantially in direct contact with body portions of the fence members 250 , 252 , 254 and 256 (see FIG. 22 ), and therefore also directs water or other accumulated fluids across away from the intersection 230 of the interconnected platform modules. Since there is still a potential for dirty water or other fluids to land on top of a fence member and then seep underneath an end portion of one of the x-seals, a plurality of small grooves disposed in the fence members cut crossways across the fence members so that any fluid that would otherwise tend to run along the bottom of the x-seal will instead be diverted in another direction by means of fluid contact with any one of the series of small cut grooves 260 depicted in FIG. 22 .
According to an example of the invention shown in FIGS. 24 a and 24 b , an appropriate x-shaped seal member 270 is shown, which in some embodiments comprises a thin metal plate 274 equipped with a plurality of leg members 272 , which depend from and around various portion of thin plate 274 . In some embodiments, leg members 272 are formed structurally integral with thin plate 274 , though in other embodiments leg members 272 comprise a plurality of separate pieces (e.g., a number of small metal rectangles) affixed to thin plate 274 using a known connection method, for example, welding the metal rectangles to the thin plate.
As seen in FIG. 25 , a further embodiment is provided wherein an outer perimeter of assembled platform modules is fitted with a safety fence 282 so that liquids that splash off the surface of the drilling platform will not pass over the sides of the platform and down onto the ground surface below. According to some embodiments, safety fence 280 comprises or retention plate 282 , which is either welded on or mechanically affixed to a body portion 284 of safety fence 280 . In other embodiments, retention plate 282 includes a portion having a double bend 284 that slips into and engages a top portion of platform section 288 at a predetermined location so as to establish the desired fluid retention fence 280 . According to still further embodiments, the presence of safety fence 280 causes splashing liquids to be diverted back toward the interior surfaces of the interconnected platform sections, though in one particular embodiment, re-directed fluid flow is allowed to drain into a container portion of a platform section by means of one or more drain holes 290 . In other embodiments, cable races are attached to the retention plates or, in further embodiments, to the platform perimeter.
Referring now to the example embodiments of FIGS. 26 a and 26 b , it will be understood that individual fluid waste retention fence members are necessarily going to be fabricated in advance at finite, predetermined lengths. According to one particular embodiment, for example, the fluid waste retention fence member measures about twelve and one-half feet long.
According to an example method of practicing the invention, as successive fluid retention safety members are installed next to other pieces of the fence, cracks that form between the kick plates are sealed using one or more fence seals 300 . In certain embodiments, fence seal sections 300 are fastened to a waste retention member using known fastening means such as a screw or a nut and bolt assembly. In one particular embodiment, the fence seal 300 is clipped onto those portions of the fence disposed nearest the gaps formed between fence sections using one or more clip tabs 302 and 304 . In a further embodiment, fence seal 300 is clipped onto the safety fence by hooking each of clip tabs 302 and 304 over a top lip portion of the kick plate. According to a particular example embodiment, a vertical fence seal portion 300 is fabricated so that it is about the same height as the terminal vertical portion of the kick plate, so that water or other fluids are directed back toward the interconnected platform sections.
Referring now to the example embodiments of FIGS. 27 a and 27 b , a retaining fence gap sealing member 312 is provided, in which the sealing member further comprises an extension member disposed thereon that is similar in both nature and function to the previously discussed four-way seal, so that excess water that seeps along an interior surface of the fence seal will again be redirected to a region contained within the perimeter of the fence. According to a specific example embodiment, platform sections on which the fence members are affixed have a plurality of cut grooves disposed beneath the sealing member that further prevents seeping fluids from migrating down the sides of the platform sections.
In the further embodiments of FIGS. 28 a and 28 b , a fence corner seal 320 is disposed so that the gap that forms between two sections of fence installed at corners of the platform is bridged. In practice, the corner seal functions similar to the other fence seals discussed above, except that the corner seal also engages multiple sections of the fence. In a presently preferred embodiment, each of the fence sections upon which the corner seal is installed is disposed at about a ninety-degree angle relative to the other.
According to the example embodiment of FIG. 29 , a number of assembled modular platform sections 50 are depicted following the installation of a plurality of deck sections atop upper portions of the platform sections. According to one embodiment, one or more manholes 54 is disposed at each end of the deck sections, except for platform section 56 , which has a shortened deck (and thus a manhole 54 disposed at only one end) due to the location of the platform's wellhead cellar 61 .
According to further embodiments, within a body portion of each of the deck sections is a utilities communication pipe 60 , which, in certain embodiments, is configured to run along an entire length (or width) of the platform section. According to one embodiment, utility pipe 60 has a predetermined number of regularly spaced junctions, permitting convenient access points for installation and maintenance of utilities related equipment (e.g., fiber optics bundles, electrical wiring, etc.). In other embodiments, utilities communication pipe 60 comprises a plurality of junctions disposed at irregularly spaced locations disposed along a length of the pipe. According to a specific example embodiment, after the disclosed arctic drilling platform has been fully assembled, communication pipes 60 (and the various junctions and utility access points disposed thereupon), serves as the framework for distribution of power and other utilities around the surface of the platform during drilling operations.
According to a further embodiment, each of the deck sections are slightly greater in length than the utilities communication pipes contained within, so that sufficient room remains within the interior of the deck module to install one or more power boxes, water junctions, or utility cross-connections, near the terminal ends of the communication pipes. In various embodiments of the invention, one or more utilities communication pipes 60 are used to accommodate installation of electrical power lines, telephone lines, fiber optic connections, gas hoses, fuel lines, etc.
As seen in the example embodiment of FIG. 30 , a crawl space is disposed between the ends of deck sections 70 and 72 . As depicted, deck sections 70 and 72 are disposed atop platform sections 74 and 76 , though those of ordinary skill in the art will appreciate that the deck sections can also be assembled in combination with other types of platform modules. According to a still further embodiment, deck sections are constructed by stacking one or more layers, wherein each layer further comprises one or more communication pipes.
According to a presently preferred embodiment, there is a space or gap of about 12 inches disposed between innermost portions 78 and 80 of deck sections 70 and 72 ; the space or gap is disposed above the topmost portions of platform sections 74 and 76 , and below a manhole cover 82 laid on a top lip established by the end points of deck sections 70 and 72 . In further embodiments, pipes 84 and 86 extend into the deck in order to facilitate utilities communication. Deck section 70 has an upper plate 88 and a lower plate 90 , each of which are usually formed from a metal or composite material of some type. For example, according to one embodiment, upper plate 88 and/or lower plate 90 are formed from an aluminum plate, though in other embodiments an aluminum alloy or other combination of materials is preferred. According to still further embodiments, an insulation material is installed in the space or gap established between the utilities communication pipes. For example, in one embodiment, polyurethane foam is placed into the space between the communications pipes to lend compressive resistance to the deck plate disposed above the crawl space.
According to the example embodiment of FIG. 31 , a utility junction 100 is disposed in proximity to utilities communication pipes 102 and 104 . The horizontal utility pipes intersect a vertical junction pipe 106 that has been cut to reflect the actual height of the space established between upper plate 88 and lower plate 90 . A drain hole 106 is opened in the lower plate 90 , so that utility lines and the like can be fed into and through the platform sections disposed below. On the top side of the deck section, a vertical pipe having a threaded engagement means 110 is prepared, so that utility lines can also be drawn out of the engagement means 110 and up into other modules affixed on top of the deck. According to a further embodiment, a plug is threaded into the threaded engagement means 110 when the portal is not in use, thereby providing a smooth deck surface that is substantially uninterrupted by open manholes.
FIG. 32 is a detailed view of a support post 50 according to the invention. In some embodiments, support post 50 is inserted into a post hole 52 that has been drilled into a ground surface. In other embodiments, support post 50 has an interior space 54 established for receiving a slurry 56 of water, sand and gravel. In still other embodiments, an external surface of the support post is smooth or flat. When the platform is assembled in a very cold environment, for example, a frozen tundra, slurry 56 will also freeze and lend additional stability and rigidity to support post 50 . According to further embodiments, a lower portion 60 of support post 50 has a spiral support fin 62 , and an upper post end 64 is configured to fit into a receiving socket 66 disposed in the bottom of platform section 68 .
FIG. 33 is a detailed view of an upper end 64 of the support post 50 shown in FIG. 32 , further comprising a process fitting 70 that allows fluids to be pumped down into a conduit or pipe 80 disposed in a body portion of the support post 50 . According to one example embodiment, fluids pumped into pipe 80 travel to the bottom of support post 50 , and a return flow is established by directing accumulated fluid pressure toward a process fitting disposed in flanged member 72 . In other embodiments, support post 50 further comprises a plurality of threaded ports 74 , so that support post 50 can be installed using an attached padeye or other fitting device (not shown).
According to the example embodiment of FIG. 34 , a terminus portion of fluid transport pipe 80 extends downwardly from a body portion of support post 50 , and then exits through a reducer port 83 and spiral fin member 82 . According to a specific embodiment, spiral fin 82 is fabricated from two metal plates, viz., a lower, rolling spiral plate 84 that extends substantially perpendicularly from an outer diameter 86 of lower pipe section 88 , and an upper, conical spiral plate 90 that extends downwardly at an angle of about thirty to forty five degrees. Rolling spiral plate 84 and conical spiral plate 90 are joined together by, for example, a known welding or sintering process, so as to establish a hollow fluid transport space 92 disposed within spiral fin 82 . In other embodiments, the exterior surface of the support post is substantially smooth and the fluid transport space is located within an interior region of the support post.
According to one example embodiment, a fluid solution is pumped downward through pipe 80 and into spiral fin 82 . The fluid circulates around the spiral fin 82 down to the bottom of the post 100 , and then vents into an internal bore 106 of support post 50 through transport hole 104 . The fluid solution then circulates back up the body of internal bore 106 . In this configuration, a liquid or gaseous medium can be pumped down the pipe 80 and around spiral fin 82 , and then back up the internal bore 106 of support post 50 to either cool or heat the ground surface area surrounding support post 50 . According to other embodiments, a very cold fluid or gas is pumped through pipe 80 into the body of the post, so as to ensure that the surrounding ground surface will remain firmly frozen. According to a further embodiment, however, a warm fluid or gas is instead pumped through pipe 80 in order to melt the ground surface around the support post, so that the support post can then be removed from its moorings and more easily retrieved when drilling operations are complete. According to a still further embodiment, the fluid transportation means is vented to a surrounding ground surface using jetting ports or the like in order to make removal of the support posts easier.
According to one particular embodiment, a fluid such as a food-grade glycol, which has a freezing temperature well below the lowest anticipated temperature of the surrounding tundra, is employed to facilitate the aforementioned freezing steps. In case of an accidental spill, food-grade glycol is also bio-degradable, and thus will have only a limited impact on the surrounding ground surface. Those of ordinary skill in the art, however, will appreciate that many other fluid solutions, for example, chilled air, heated air or hot steam, can be pumped through the support post 50 in order to carry out the aforementioned freezing and heating.
On heavily weighted platforms, individual support posts often bear a heavy load. Since in some embodiments the support posts are frozen into the surrounding ground surface using a slurry, there can be a tendency for the underlying ice to either shift or compact, thereby causing one or more of the posts to sink more deeply into the ground and destabilize the rest of the platform. In most cases, the sinking of a post is in proportion to the load it bears, and will vary from post to post. While it is anticipated that the incremental sinking of any individual post will usually have a negligible impact on the stability of the platform, those of ordinary skill in the art will appreciate that a mechanical adjustment will sometimes be required to bolster the structural support capacity of some sinking posts. According to the invention, there are at least two different effective methods of improving the support capacity of sinking posts.
According to the embodiment shown in FIG. 35 , for example, a platform and deck assembly 350 is supported by a support post 360 , wherein a jacking assembly 370 is disposed above a lift socket 365 located on a topmost portion of the support post 360 . As seen in the embodiment of FIG. 36 , a hydraulic cylinder 375 is then extended down from the jacking assembly 370 until contact with the support post lifting socket 365 is established. According to some embodiments, the engagement means provided to ensure a reliable mechanical interface between cylinder head portion 380 and lifting socket 365 is a slip-toothed sprocket assembly. In other embodiments, the engagement means comprises a known fastener assembly, for example, a nut and bolt assembly. Those of ordinary skill in the art, however, will recognize that virtually any type of engagement means could be used to hold the cylinder head 380 in place against the support post receiving socket 365 , so long as the engagement means is sufficient to reliably facilitate the secure attachment of cylinder head 380 to the top of the support post.
In further embodiments, hydraulic cylinder 375 is shaped like a piston, and exerts a downward force against the head of the support post so as to engage the two members via the fastening means. According to still further embodiments, however, the hydraulic cylinder member 375 is a telescoping cylinder, so that successive, concentric portions of the cylinder are revealed as the cylinder is extended to engage with the support post lifting socket 365 , and the platform and deck assembly 350 are then lifted.
As seen in the example embodiment of FIG. 37 , once the platform and deck assembly 350 have been lifted off of the shoulder of adjustable nut 368 by means of attached jacking assembly 370 , adjustable nut 368 is relieved of its weight load and can then be height-adjusted without further disturbing the level or stability of the surrounding platform. As seen in the example embodiment shown in FIG. 38 , after adjustable nut 368 has been re-adjusted to a desired setting, platform and deck assembly 350 is set back down onto a flanged receiving portion 369 of adjustable nut 368 by means of hydraulic cylinder 375 , and cylinder head 380 is unfastened or otherwise withdrawn from support post lifting socket 365 . As shown in the example embodiment of FIG. 39 , after the desired platform height adjustment is completed, jacking assembly 370 can then be removed from the vicinity of support post 360 and used elsewhere on the platform if desired.
As shown in the example embodiment of FIG. 40 , platform and deck assembly 350 need not necessarily be lifted from above in order to relieve the weight load disposed on the support post 360 . For example, jacking assembly 390 can also be installed underneath the platform and deck assembly 350 , and then used to lift the platform off of the support post 360 by pushing a top surface of the cylinder against a bottom surface of the platform and deck assembly 350 and then driving the cylinder upward using the cylinder's hydraulic system.
In instances where the hydraulic cylinder is piston shaped, the stroke distance of the hydraulic cylinder effectively determines the extent of support post height adjustment that can be effected. However, in other embodiments, one or more cylinder retaining pins can also be disposed in-between the jacking assembly's telescopic cylinder members in order to provide a standardized range of support post height adjustments. According to a particular embodiment, for example, a plurality of retaining pins is inserted through regularly spaced receiving holes formed in body portions of the inner, middle and outer telescopic cylinder members. As the cylinder progresses through a stroke cycle and retaining pins are inserted into the receiving holes, a basic height for the jack assembly is established at one of several predetermined elevations.
According to a detailed example embodiment, a bottom jack assembly is positioned adjacent to a side portion of a platform in such a fashion that the jack's hydraulic cylinder traverses a first portion of its stroke distance. A chain or other lifting means is then wrapped around the raised cylinder head, and the pins are removed from the cylinder's telescopic body sections. When the cylinder is retracted, the telescopic sections are pulled back in and the pins are reinserted. The cylinder is again extended, and slack in the restraining chain is withdrawn, so that the height of the cylinder head is raised; at that point, the cylinder head is held in place by only the shortened restraining chain. The pins are then pulled out of the receiving holes again, and the cylinder is retracted. As before, the telescopic cylinder members are raised to a higher position and then re-pinned, this process being repeated until the cylinder head has been raised to its desired height using only the hydraulic lift strength of the jack assembly. After the height of hydraulic cylinder head is basically adjusted, the jack assembly is slid into place under a desired portion of the platform, and the cylinder head is again extended to permit final adjustment of the height of the support posts.
According to the further embodiment of FIG. 41 , an installed support post 54 comprises a tube-like member 50 disposed through a body portion of a platform section 52 , wherein the support post 54 is inserted from below into a cylindrical interior space formed in post tube 50 . An adjustable nut 56 is disposed on a body portion of support post 54 so as to engage a bottom surface 58 of platform section 52 . According to some embodiments, engagement between adjustable nut 56 and platform bottom surface 58 further comprises an insulating member 60 . When the insulating member 60 is formed from a poorly conductive material such as, for example, Delrin or UHMW polyethelene, the insulating member serves to establish an electrical ground between the steel adjusting nut 56 and the aluminum platform section 52 .
According to other aspects of the invention, a tapered receiving member 62 disposed on an upper portion of adjustable nut 56 resides within tube member 50 after the support post is installed. A first chocking assembly 70 is then lowered down into the space formed between the tube member 50 and support post 54 so as to engage both the tapered receiving member 62 and an inner wall surface 78 of tube member 50 . In the particular embodiment depicted in FIG. 41 , a lower wedge member 72 is disposed to engage the adjustable nut 56 at a lower location, and to support an additional tapered receiving section 74 disposed on a topmost portion of chocking assembly 70 . Likewise, an upper wedge 76 is disposed to engage the topmost portion of tapered receiving section 74 and inner wall surface 78 of tube member 50 .
FIG. 42 is a top view of the support post head shown in FIG. 41 . According to one example embodiment, several chocking assemblies 70 are disposed around a perimeter region of support post head 80 in order to hold the support post 54 securely in place and lend additional stability and structural rigidity to the system after installation is complete.
For example, disposition of multiple chocking members 70 and 74 provides a fixed side distance between the support post and an interior surface of the platform section tube member, so that side loads (e.g., forces being delivered to the sides of the platform, such as strong winds) will be uniformly absorbed across an entire cross-section of the support post portion installed within the tube member. Since both top and bottom portions of the support post are engaged with interior surfaces of the tube member, the support post and tube member assembly is substantially fixed, and lends additional structural rigidity to the platform system. If, on the other hand, the support post is fixed at only the bottom of the tube member, a pivot-like connection between the support post and platform section results, and a high inertial moment established near the ground surface reduces stability of the assembled platform system. FIG. 43 is a perspective view of the support post head shown in FIG. 41 , wherein several of the design features described above with respect to FIG. 42 are emphasized.
Turning now to other aspects of the invention, FIG. 44 is a proposed platform floor plan in which the general arrangements of storage buildings and other necessary structures are depicted. Care must be given to the layout and grouping of platform structures so that related equipment is strategically stored, safe and comfortable housing is available for platform personnel, and to ensure that the rig is in compliance with strict fire and safety codes.
For example, according to specifications promulgated by the American Petroleum Institute (e.g., the API 500 specifications), a five-foot radius around the bell of any drilling rig is considered a Division One explosion environment, and all electrical equipment used in the area must be configured to accommodate the requirements associated with a Class One Division One area. Most enclosed structures that have a door opening out to a Division One environment are considered Class One Division Two explosive environments, environments that, under the API regulations, are regulated nearly as restrictively as Class One Division One areas. In practice, virtually all electrical equipment used on the rig, including computers and telephones, must be reviewed for electrical explosion potential in order to comply with the mentioned industry regulations.
In the example embodiment of FIG. 44 , a driller's doghouse 50 is disposed on one side of the drilling rig 52 , and a company man house 54 is disposed on an opposite side of the rig 52 . Both the driller's doghouse and the company man house have a picture window 56 and 58 , so that personnel can look onto the drilling floor 60 .
It would also be desirable for both the driller's doghouse and the company man house to have a doorway that permits personnel stationed in these offices to walk out onto the rig floor to perform work or conduct discussions regarding rig activities; however, the presence of a doorway between the rig floor and either the driller's doghouse or the company man house would cause these areas to be classified as Division Two areas, and since both the drillers and the company men often have need for telephones and portable computers and the like, most of which are not explosion-proofed, it has in the past been the case that convenient doors between the rig floor and the personnel stations are not present.
As seen in the example embodiment of FIG. 45 , in which a building structure from the floor plan of FIG. 44 is isolated in greater detail, rig floor access difficulties are overcome by constructing a company man house 54 that is actually a combination of a company man room 70 and a computer and communications room 72 . In a substantially central portion of the company man house 54 , a door 80 opens into a small hallway 82 , rather than directly into the company man room 70 . According to one embodiment, the small hallway 82 passes straight through the company man house 54 and is fully opened to the environment on a side 84 opposite the door 80 . Since door 80 opens into a hallway 82 that is open to the environment, hallway 82 becomes a non-classified area, and company men can use the telephones and computers provided in computer room 72 without conflicting with the industry regulations.
Turning now to various storage structures that are useful in a platform environment, for example, liquid storage platform sections, an embodiment of the invention depicted in FIGS. 46 and 47 comprises a platform section 50 that has a deck section 52 installed on top of the platform. In some embodiments, support foam 54 disposed within deck section 52 provides a layer of insulation at the top of the deck portion; in a presently preferred embodiment, the layer of insulation is about six inches thick. A plurality of six-inch insulation members 56 have also been added to the ends, bottom, and both sides of the platform and deck sections, effectively making the storage module a large thermal container.
In some embodiments, the floor of thermal container 52 further comprises an electric heating element 60 ; lying on top of the heating element is a balloon type tank or collapsible pillow tank 62 . In some embodiments, the balloon tank stores fresh water that can later be processed into either potable water or water suitable for use in showers and sinks. According to other embodiments, balloon tank 62 is used to store other liquids, for example, diesel fuel or well operation fluids. In further embodiments, a pump 70 is used to draw fluid out of the bladder tank prior to transfer of the fluid into other parts of the platform structure. In still further embodiments, pump 70 is used to draw liquids from other platform sections, and to pump the drawn fluids into the bladder tank through appropriate process connections 72 , for example, a metal pipe or durable plastic conduit connection.
Those of ordinary skill in the art will appreciate that there are usually a great many platform areas that are stacked high with relatively heavy platform modules and drilling equipment. However, there are also many other areas, for example, the deck sections beneath the crane, which are lightly loaded. By using one of the liquid storage bladder configurations, fluid loads can be maintained in platform sections that functionally serve as open deck spaces. The liquid storage bladders are also lighter than the steel tank storage modules that are presently known, and thus the total weight required to be supported is reduced according to the invention.
Most liquids suitable for storage in the disclosed bladder will tend to freeze at very low temperatures, for example, the very low temperatures that would be expected in arctic drilling environments. In the example embodiment of FIGS. 46 and 47 , problems associated with freezing fluids are overcome using one or more electric heaters disposed along the bottom of the bladder tank. According to further embodiments, however, one or more additional heating strips is applied directly to the bottom of the tank, or is instead applied to the bottom of an aluminum plate laid on the bottom of the platform section so that the bladder tank is disposed on top of the aluminum plate. The aluminum heating plates provide superior temperature distribution, and generally will not cause hot spots that can overheat a particular area of the bladder like other known methods of tank heating. According to further embodiments, hot air is circulated within the storage section to prevent the stored fluid from freezing; in still other embodiments, electric heaters are disposed within the fluid so that warm water is continuously circulated through the storage tank.
FIG. 48 is a cross-sectional view of a wellhead cellar according to one aspect of the invention, in which an outer portion of the wellhead cellar is comprised of multiple layers, for example, an inner skin and an outer skin, with two-part polyurethane foam insulation disposed between the inner and outer skins. In the bottom of the wellhead cellar, there are at least two levels of seals provided to ensure the unit is as environmentally secure as possible and that the ground surface is protected from inadvertent spills. The disclosed wellhead cellar also permits the entire drilling operation to be carried out without disturbing any of the ground surface except for the production hole.
As seen in the example embodiment of FIG. 49 , the wellhead center cellar further comprises additional sets of casing and the like suitable for use in additional wellbores. According to further embodiments of the invention, the backup casings are also sealed within the wellhead cellar to prevent leakage, and to maintain the environmental integrity of the drilling operation. In a further embodiment, a ladder or stairs provide access to personnel required to move into and out of the wellhead cellar.
As seen in the example embodiment of FIG. 50 , a wellhead cellar sealing assembly engages an outermost stream of production casing. The seals comprise an inner and outer skin, with polyurethane foam disposed in-between. According to some embodiments, each of the seals are energized using bolts attached by known fasteners in order to provide a secure and reliable sealing assembly for the protection of wellhead. Other means for energizing the seals include introduction of low pressure air feeds, for example, an air feed having about 2 PSI, so that the seals are held fast after attachment by means of compressive pressure or the use of a sealant such as foam.
FIG. 51 is a post hole in which a platform support post 50 is disposed according to further aspects of the invention. The support post 50 has an adjustable nut 56 for making fine adjustments to the level of the platform 52 disposed thereon, and a fluid transfer means 58 that permits fluid to be pumped from the platform down inside the body of the support post 52 for heating or cooling operations. A lower end 60 of support post 50 is contoured to permit pumped fluids to flow toward the bottom of the support post for full, uniform heating of the support post. At the lower end of the support post 50 , a smaller diameter section 62 is for engagement with an extension member.
As seen in the example embodiment of FIG. 52 , an adaptor 70 useful for adding an extension onto the bottom of a support post is provided. According to some embodiments, adaptor 70 has an internal bore 72 sized to engage a smaller diameter section 62 of the bottom of support post 50 . According to certain embodiments, one or more fastening bolts 74 are also provided; in a particular example embodiment, the fastening bolts 74 are disposed at 90 degree intervals around the circumference of the device, and engage and lock onto the bottom of the support post 50 . Disposed on a bottom portion of the adapter 70 is an extension receiving member 76 , sized to engage a piece of extension pipe that is added to the bottom of the adapter 70 . FIG. 53 shows the adaptor 70 of FIG. 52 , with the mentioned extension pipe section 80 attached thereto. According to one aspect of the invention, the extension member 80 is welded onto a bottom portion of the extension receiving member 76 , though in other embodiments any known fastening means will suffice so long as the connection between the extension member 80 and the extension receiving member 76 is secure and dependable. For example, certain embodiments use shear pins or the like to secure the extension member and the extension receiving member so that the connection will break apart when a predefined amount of force is applied.
As seen in the embodiment of FIG. 54 , a bottom portion of support post 50 has a lower end 60 sized so as to engage within an interior surface of extension receiving member 72 (see FIG. 52 ). In the embodiment of FIG. 55 , the support post has an extension member added, with the outer surface of lower end 60 being attached to the extension receiving member 72 using a plurality of fastening bolts 74 .
According to the further embodiment of FIG. 56 , a post hole 100 is depicted in which a platform support post is disposed. Extension member 84 has already been friction-locked to a bottom end of the support post. After the support post is inserted into the post hole, a slurry of water, sand and gravel is added to freeze the support post in place. At this point, the support post is ready for supporting the raised load for which it was designed.
Referring now to the example embodiment of FIG. 57 , the post hole shown in FIG. 56 is depicted after removal of the support post from the post hole. According to some embodiments, the support post is heated using circulated warm fluid so as to unfreeze the post from the surrounding ground formation. The plurality of bolts used to fasten the extension member to the extension receiving member are then removed or sheared, so that the support post can in turn be removed from the adapter and extension member. According to one embodiment, the adapter and extension member remain in the ground afterward, buried well beneath the surface of the surrounding ground formation. In some embodiments, the adapter and extension member are left in the ground about fifteen to twenty feet beneath the ground surface. In some embodiments, the adapter and extension are forever abandoned, and the post hole is filled in or covered over so that only minimal signs of the drilling operation are imprinted on the surrounding ground surface. However, in other embodiments, the adapter and extension member assembly are re-used whenever production from the site is again desired, and thus the post hole is not filled in or covered over. According to still further embodiments, the adapter and extension member assembly are abandoned, and the upper portion of the post hole is refilled with a slurry of sand and ice. In still other embodiments, the post hole is re-filled with a mixture of tundra and ice, and thus the former drilling site cannot easily be discerned from the surrounding tundra after operations have been completed and the platform has been removed.
The foregoing specification is provided for illustrative purposes only, and is not intended to describe all possible aspects of the present invention. Moreover, while the invention has been shown and described in detail with respect to several exemplary embodiments, those of ordinary skill in the art will appreciate that minor changes to the description, and various other modifications, omissions and additions may also be made without departing from either the spirit or scope thereof.
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The instant disclosure relates to a system and method of constructing drilling and production platforms that are particularly useful in remote, inaccessible and/or environmentally sensitive operating environments. According to one aspect of the invention, an arctic drilling platform is provided wherein various methods and means of interlocking neighboring platform modules are provided. Methods and means for sealing the intersections formed between a plurality of interlocked platform modules are also disclosed. According to further aspects of the invention, improved platform floor plans are provided, and various wellhead cellar layouts and sealing means are also described. Methods and means of enhancing the usefulness of modular storage platforms are disclosed, and a number of support post installation and removal techniques are also provided. Also taught are a variety of methods of adjusting the height and level of an assembled drilling platform, and methods and means of adding extension members useful for extending the length of a support post are also described.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation of application Ser. No. 09/304,566, filed May 4, 1999, now U.S. Pat. No. 6,505,395, issued Jan. 14, 2003, which is a divisional of application Ser. No. 09/140,920, filed Aug. 26, 1998, now U.S. Pat. No. 6,202,292 B1, issued Mar. 20, 2001.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to apparatus for removal of a carrier film from the bottom surface of semiconductor dice and other electronic devices. Particularly, the apparatus of the present invention reduces the surface area of the adhesive film which remains in contact with a die during removal. The present invention also relates to a method for removing semiconductor dice and other electronic devices from carrier film.
2. Background of Related Art
Several apparatus and methods are known for removing semiconductors and other electronic devices from adhesive carriers such as film. Some such methods involve degrading the adhesive properties of the carrier. Some devices employ needles, pistons, or other mechanisms which apply an upward force to push the die off of the carrier. Other devices utilize a vacuum to pull a die from a carrier. Many known apparatus and methods for removing a die from a carrier cause damage to a significant quantity of dice.
U.S. Pat. No. 4,778,326, issued in the names of Althouse et al., discloses a method and apparatus for transporting semiconductor dice which is commonly referred to as a “gel pack” or “die-pac.” The semiconductor dice are loaded onto and adhere to a flat, thin, flexible silicone film, which is attached to a carrier base. The carrier base has recesses formed therein, into which the silicone film may be pulled as a vacuum is applied beneath the film. As the film is pulled into the recesses, the area of the silicone film which contacts the dice is reduced, thereby reducing the magnitude of the adherence by which the dice are attached to the film. The dice may then be easily removed with a vacuum tip.
As mentioned above, the predominant use of gel packs is to transport dice. No semiconductor fabrication processes are performed while dice are on a gel pack. Use of gel packs is somewhat undesirable because the silicone of the films tends to contaminate dice by leaving a silicone residue thereon.
U.S. Pat. No. 5,590,787, issued in the name of Hodges, discloses another die-pac device for transporting semiconductor dice. The device of the '787 patent includes a UV sensitive adhesive and permits the penetration of electromagnetic radiation, such as ultraviolet light, therethrough.
Techniques which utilize carrier films having ultraviolet light (UV) degradable adhesives thereon or other degradable adhesives are also well known in the art. The area of film attached to a die which has been selected for further manufacture is irradiated with the appropriate degradative source to remove the die from the film. Although the use of UV radiation and similar methods are desirable from the standpoint that they are unlikely to damage the die, the adhesives and carrier films required for such devices and processes are very expensive. UV-release carrier tapes have also been employed to a limited extent with gallium arsenide dice.
U.S. Pat. Nos. 4,990,051 and 4,850,780, each of which issued in the names of Safabakhsh et al., each describe an apparatus for removing a die from an adhesive carrier film. That apparatus concurrently applies a vacuum to the exposed surface of the die and a chuck to the film on the opposite surface of the die. The vacuum collet is moved away from the chuck, which facilitates a pre-peel of a small area of the film from the periphery of the die. A piston disposed coaxially within the chuck is then forced against the carrier film to stretch the film and further reduce the area of the film which adheres to the die, thereby facilitating removal of the die from the film.
Some other apparatus for removing dice flow a carrier film include a plunge-up piston which has a cap thereon to raise a selected die in relation to the adjacent dice on the film. This process is referred to as “tenting” the film. A needle disposed within the cap is actuated to contact the die from below and push it from the carrier film as a vacuum tip positioned above the die pulls the selected die away from the film.
Such tenting processes for removing dice from film are undesirable for several reasons. First, tenting sometimes creates an air bubble under the die, which tends to tilt the die, preventing the vacuum tip from obtaining a good hold on the die. In such cases, the vacuum tip will likely drop the selected die, damaging and/or contaminating the die. Second, in many such apparatus, the needles which push the selected die from the film have pointed ends, which tend to score the bottom surface of the die. Dice which have been scored in such a manner tend to subsequently fail mechanically at the location where they have been scored. Third, as the film is tented, the edges of other dice which are adjacent to the selected die may be chipped, causing damage to the circuitry on their active surfaces, with consequential failure.
U.S. Pat. No. 4,915,565, issued in the names of Bond et al., discloses an apparatus for removing a selected die from a wafer having an array of dice which is attached to a carrier film. In the apparatus of the '565 patent, the dice are positioned beneath the film during removal of each selected die. A head having an array of needles protruding therefrom is positioned over the film opposite a selected die. In operation, the head plunges toward the film, the needles penetrating the carrier film and dislodging the die from the film. The dislodged die then falls into a receptacle. U.S. Pat. No. 4,759,675, issued in the names of Bond et al., discloses the same die removal device.
The sole use of needles to remove a selected die from a carrier film makes the removal device of the '565 and '675 patents undesirable. The adhesive forces of the film to the die necessitate a large amount of force for removing the die therefrom. Further, the orientation of the plunge head relative to the die requires that the die suffer some impact when falling into a receptacle, increasing the likelihood of damage to the die.
U.S. Pat. No. 4,285,433, issued in the names of Garrett, Sr. et al., describes another method and apparatus for selecting and removing singulated dice from a wafer. The apparatus includes an adhesive film which is attached to the bottom of the carrier film supporting the dice. The adhesive film with adhered carrier film is pulled away from the dice through a slot. U.S. Pat. No. 4,607,744, issued in the name of Pak, discloses a similar method and device which removes carrier film from dice with a take-up drum which pulls a free end of the carrier film. The carrier film is pulled around a separator edge into a slot, the dice then passing over the separator edge and onto a conveyor which transports the dice away from the separator edge.
The amount of force applied to the dice as the carrier film is pulled downward through such a slot or separator edge while the dice proceed in a different direction of travel may be sufficient to break or damage the dice. Further, the processes of the '433 and '744 patents are undesirable in that they do not permit automated removal of selected dice from an array of dice including failed dice and die fragments, as well as functional dice.
As dice become thinner and are fabricated with larger surface areas (which adhere to a greater area of the carrier film), the likelihood of their being damaged by each of the foregoing mechanical removal processes increases.
Thus, an apparatus is needed for removing disposable carrier tape or film from semiconductor dice and other electronic devices which exerts little or no impact on a die, reduces the area of carrier tape or film adhered to a die before removal of the die, and utilizes an inexpensive yet effective carrier tape or film.
BRIEF SUMMARY OF THE INVENTION
In contrast to the deficiencies exhibited by the prior art, the low-stress die removal system of the present invention addresses each of the foregoing needs. The apparatus is useful with many disposable carrier tapes or films known and used in the art. The apparatus also exerts little, if any, impact on the die. The apparatus of the present invention also significantly reduces the surface area of carrier film adhered to a die before removal. The die removal apparatus does not require the use of expensive films which have degradable adhesives thereon.
One embodiment of the die removal apparatus of the present invention includes a base, including a plate member encircled by a raised periphery, a screen disposed over the plate member, and a vacuum source to create a vacuum within the base and below the screen. The plate member may include recesses therein to ensure application of the vacuum to all portions of the base within the periphery. A carrier film having dice on the upper surface thereof is placed above the plate, and the vacuum is used to pull the film against the screen and away from the dice.
In a variation of the die removal apparatus of the present invention, the plate member includes a series of laterally spaced supports protruding upwardly therefrom. The portions of the screen which overlay the supports may be higher than those portions which rest within the recesses. Another variation of the base of the die removal apparatus of the present invention lacks a screen and merely employs supports. Alternatively, a plate member may be formed with apertures therethrough and the film is pulled thereagainst and with the aperture upon activation of the vacuum source. In yet another variation, the upper face of the plate is provided with bumps, convolutions, or other protuberances separated by valleys into which the carrier film may be pulled.
In use, a frame ring which engages a carrier film with a wafer thereon is positioned over the base. The film preferably rests upon and is supported by the plate member. As the vacuum source is activated, the portions of the carrier film which overlay the recesses are pulled against the screen, supports, or protuberances and into the recesses or valleys. Thus, the area of the film which remains adhered to the dice is reduced by an amount which depends upon the size of the recesses and the strength of the vacuum. Consequently, the adherence of each of the dice to the carrier film is reduced. Dice which have been selected for further processing (referred to individually as a “selected die”) are then completely separated from the carrier film by a removal mechanism, which removes each selected die by pushing, pulling, or pushing and pulling each selected die from the film. Preferably, separation occurs while the film is being pulled downward against the plate member.
The die removal apparatus according to the present invention may also include a vacuum head which is positionable above a selected die. The vacuum head pulls the die from the carrier film upon activation of a vacuum source to pull a substantial portion of the film away from the back side of the die. When combined with the significantly reduced adhesion area of the film to the die, very little force is required to remove the die from the carrier film. Further, because the die rests securely upon and remains supported by the plate member, tilting of the die is unlikely.
The die removal apparatus may also comprise a low-impact plunge-up head which is positionable beneath a selected die and has one or more needles which may be extended upwardly therefrom in a telescoping manner. After the plunge-up head is positioned beneath the selected die, the needle is actuated to push the die away from the carrier film. When combined with the significantly reduced adhesion area of the film to the die, afforded by the previously-mentioned base construction and application of vacuum to the back side of the film, very little force is required to remove the die from the carrier film. Preferably, the plunge-up head is used in combination with a vacuum head which is positionable above the selected die. Preferably, when used in combination, as the plunge-up head needle pushes the die upward, the vacuum head simultaneously lifts the die to transfer it to another location. As with the first embodiment of the removal mechanism, the likelihood of damaging a selected die is much less than that of methods which were previously known in the art.
Other advantages of the present invention will become apparent to those of ordinary skill in the art through a consideration of the appended drawings and the ensuing description.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
FIG. 1 a is a perspective view of a preferred embodiment of the present invention;
FIG. 1 b is a cross-section of the base of the present invention, taken along line 1 b — 1 b of FIG. 1 a and showing an assembly including a frame ring, carrier film and a sawed wafer on the carrier film;
FIG. 2 a is a cross-sectional view of a second variation of a base of an apparatus according to the present invention;
FIG. 2 b is a cross-sectional view of a third variation of a base of an apparatus according to the present invention;
FIG. 2 c is a cross-sectional view of a fourth variation of a base of an apparatus according to the present invention;
FIG. 2 d is a cross-sectional view of a fifth variation of a base of an apparatus according to the present invention;
FIG. 2 e is a cross-sectional view of a sixth variation of a base of an apparatus according to the present invention;
FIG. 3 is a frontal perspective view of another variation of a base of an apparatus according to the present invention;
FIG. 4 is a cross-sectional view of an apparatus according to the present invention, also showing a first preferred embodiment of a die removal mechanism;
FIG. 5 is a cross-sectional view of an apparatus according to the present invention, illustrating a second preferred embodiment of a die removal mechanism;
FIG. 5 a is a top plan view of a variation of a support plate of the present invention;
FIG. 6 is a cross-sectional view of a die removal mechanism according to the present invention;
FIG. 7 is a cross-sectional view of a second die removal mechanism of this invention;
FIG. 8 is a frontal perspective view of a variation of the base of the present invention, wherein the base is positionable relative to a selected die; and
FIG. 8 a is a frontal perspective view of another variation of the base, wherein the base is positionable relative to a selected die.
DETAILED DESCRIPTION OF THE INVENTION
With reference to FIGS. 1 a and 1 b , a first preferred embodiment 100 of the low-stress die removal apparatus of the present invention is shown. Apparatus 100 includes a base 110 , including a plate member 120 , a screen 112 positioned over the plate member, and a vacuum source 114 connected to the base beneath the plate member. Preferably, embodiment 100 also includes a vacuum pick-up head 116 , positioned above base 110 . Vacuum pick-up head 116 is also operably connected to a vacuum source 117 , which may comprise vacuum source 114 or a second vacuum source.
FIGS. 1 a and 1 b also depict a diced wafer 101 disposed upon a carrier film 104 , which may also be referred to as a carrier tape, film, or tape. Diced wafer 101 includes several singulated dice 102 a , 102 b , 102 c , etc. A frame 106 , also referred to as a ring or a frame ring, supports carrier film 104 under tension for transport of wafer 101 . Preferably, frame 106 has a shape and dimensions which facilitate placement upon and connection with the top of base 110 . Preferably, in embodiments of the invention where a plunge-up head 550 (FIGS. 6 and 7) is employed, the perimeter ring 111 of base 110 is of similar size to flame ring 106 , there being enough lateral clearance between the perimeter ring and the periphery of wafer 101 for the plunge-up head to operate. The foregoing elements are collectively referred to as wafer assembly 108 .
Base 110 includes a plate member 120 having an uneven or bumpy surface, which includes a plurality of raised members 124 a , 124 b , 124 c , etc., extending upwardly from the surface of the plate member, which may also be referred to as supports. Spaces 122 a , 122 b , 122 c , etc. are formed between supports 124 a , 124 b , 124 c , etc. Although FIG. 1 a shows supports 124 in a staggered arrangement, the supports may also be configured in straight rows or in any other configuration which facilitates removal of carrier film 104 from a die 102 while adequately supporting the die. Similarly, while the top of each of the supports 124 shown in FIG. 1 a has a small surface area, other configurations of supports are also within the scope of the apparatus of the present invention, including, without limitation, horizontally elongate supports, larger supports having a shaped (e.g., circular, square, rectangular, triangular, oval, n-sided polygonal and others) orthogonal cross-section with a hollow center, concentrically arranged shaped supports, and other configurations of supports. The shape, the arrangement and the spacing of supports 124 are preferably sufficient to facilitate pulling a significant portion of carrier film 104 from each of dice 102 . Yet, the shape, arrangement and spacing of supports must also adequately support each of the dice 102 and reduce the likelihood of fracturing or otherwise damaging the die as portions of the film are removed therefrom by a vacuum.
Referring to FIG. 1 b , screen 112 , which is preferably flexible, rests above plate member 120 . Supports 124 a , 124 b , 124 c , etc., and spaces 122 a , 122 b , 122 c , etc. impart screen 112 with an uneven surface, which includes peaks 128 and valleys 130 . Suitable materials for manufacturing screen 112 include, but are not limited to, wire mesh, silk screens, thin layers with a plurality of fenestrations formed therethrough, and other meshes and screens which permit the flow of air therethrough. Woven as well as punched screen materials may be employed. Anti-static materials are preferred.
Vacuum source 114 is operatively connected to base 110 through vacuum port 115 . As vacuum source 114 is activated, air is pulled through screen 112 and the carrier film 104 is pulled away from the dice 102 until it contacts the screen material. Thus, vacuum source 114 facilitates the removal of the portions of carrier film 104 which overlie valleys 130 from the backs of dice 102 .
FIG. 2 a illustrates an alternate variation of base 210 , wherein the screen 212 is a substantially flat member positioned above plate member 220 . Plate member 220 includes supports, also referred to as raised members 224 , extending upward therefrom through the screen, and forming a bumpy or uneven surface above the plate member. Supports may be arranged in straight rows, staggered, or in any other configuration which facilitates removal of the carrier film from the dice while adequately supporting the dice.
FIG. 2 b depicts a third variation 310 of the base, which includes a plate member 320 with a plurality of vacuum orifices 332 a , 332 b , 332 c , etc. formed therethrough. Each of vacuum orifices 332 is operably connected to a vacuum source 314 . Preferably, vacuum orifices 332 are consistently spaced over substantially the entire surface of plate member 320 . Embodiment 310 also includes supports, or raised members 324 , extending upwardly from the surface of plate member 320 to create an uneven surface thereon.
FIG. 2 c depicts a fourth variation 340 of the base, wherein plate member 342 has a substantially flat bottom surface and an uneven top surface having a plurality of peaks 344 and valleys 346 formed thereon. Plate member 342 may also include vacuum orifices 348 formed therethrough which, upon activation of a vacuum source (not shown), facilitate the removal of gas from valleys 346 . Alternatively, the vacuum source may connect to outside of the base through the sidewall thereof and adjacent the bottom, as long as the peaks 344 are higher than the distance a carrier film may be drawn thereinto.
FIG. 2 d illustrates a fifth variation 350 of the base, which includes a self-supporting, highly convoluted screen 352 , which includes a plurality of peaks 354 and valleys 356 . Screen 352 may be manufactured from the same materials as those described above in reference to screen 112 of FIG. 1 b . As used herein, the term “screen” not only encompasses screens having transversely dispersed woven elements, but may comprise a plurality of convoluted elongated elements extending in mutually parallel relationships, preferably with offset peaks and valleys in adjacent elements. Also, in an embodiment employing a screen without associated discrete supports, it will be understood that the laterally spaced peaks or protrusions of the screen comprise laterally spaced supports.
FIG. 2 e shows a sixth variation 360 of the base, which includes a plate member 362 with a plurality of upwardly extending support pins 364 thereon. Each of the support pins 364 includes an enlarged head 366 at the top thereof, against which a carrier film may be drawn.
Referring now to FIG. 3, another variation 370 of the base is shown. Base 370 includes a plate member 372 which has a plurality of apertures 376 formed therethrough. A wafer assembly (not shown) is supported on supports 374 , which are located between adjacent apertures 376 of plate member 372 . Preferably, supports 374 are narrow members. Apertures 376 , which impart plate member 372 with a honeycomb-like appearance, may have any shape, including, without limitation, circular, hexagonal, square, oval, and other shapes. Further, the walls defining the aperture may be undercut, as shown in broken lines, to permit the film to be drawn lower in select areas.
Referring again to FIG. 1 b , as an example of the use of the base 110 of the apparatus of the present invention, the carrier film or film 104 , upon which a sawed, processed wafer 101 is positioned, is placed upon the base over screen 112 . Frame ring 106 secures wafer assembly 108 to base 110 . Next, vacuum source 114 is activated, pulling air through the spaces 122 , which pulls portions of carrier film 104 against the surfaces of screen 112 which overlay the recesses, releasing those portions of the film from dice 102 . Selected dice are then ready for removal from carrier film 104 . As defined herein, the terms “select die” and “selected die” refer to a die which has been selected for removal from sawed wafer 101 for further processing. In systems where embodiments 210 , 310 , or other embodiments of the base of the present invention are employed, the methods for removing portions of the carrier film from the dice are substantially the same.
Referring now to FIG. 4, an embodiment 400 of a die removal mechanism is shown. Embodiment 400 includes vacuum head 410 , which is positionable over a base 420 and operatively connected to a vacuum source 430 . Several dice 102 a , 102 b , 102 e , etc., which are disposed upon a carrier film 104 , are shown. Vacuum head 410 is positionable directly above a selected die 102 a . Systems which select dice, track select dice, and position a vacuum head above a selected die, are each well known in the industry and are useful in connection with the apparatus of the present invention. Upon activation of vacuum source 430 , vacuum head 410 utilizes a vacuum to pull selected die 102 a upward from carrier film 104 . Vacuum die pick-up mechanisms, which are well known and currently used in the industry, are useful in the system of the present invention.
FIG. 5 shows another embodiment of a die removal mechanism 500 , according to the present invention, which includes a vacuum head 510 and a die plunge-up head, also referred to as striking mechanism 550 . FIG. 5 also shows several dice 102 a , 102 b , 102 c , etc. disposed upon a carrier film 104 . The carrier film 104 is secured by a frame ring (not shown). Preferably, vacuum head 510 operates in substantially the same manner as that described above in reference to FIG. 4 .
Die plunge-up head 550 is of the type known and commonly used in the industry. Die plunge-up head 550 , which is positionable beneath a selected die 102 a , includes one or more needles 554 slidingly disposed within a bolder 552 . Plunge-up head 550 also includes an actuator 556 disposed behind needle 554 . Preferably, the size of plunge-up head 550 is sufficient to include a plurality of needles 554 , reducing the tendency of a selected die 102 to tilt as the needles strike the die. Systems for selecting good dice, tracking select dice, and positioning plunge-up head 550 beneath a selected die 102 a are well known in the industry and may be used in connection with the apparatus of the present invention. Alternatively, the plunge-up head 550 may include another plunge-up mechanism such as a piston or a pressurized air line.
Actuators which are useful with die plunge-up head 550 include, without limitation, conventional two-way pneumatic actuators and solenoid actuators, such as those which are known and used in the industry, or any other type of actuator adaptable for use with plunge-up head 550 . Actuator 556 forces needle 554 upward with the appropriate amount of force and for the appropriate time period to, either directly or indirectly, further loosen selected die 102 a from carrier film 104 without damaging the selected die, then retract the needle into holder 552 . Preferably, in embodiments of the present invention, needle 554 extends through a base aperture 553 to directly contact selected die 102 a .
FIG. 5 illustrates small base apertures 553 . However, as FIG. 5 a shows, the plate member 120 ′ may have a grid configuration. Support members 124 ′ extend upwardly from intersecting portions of plate member 120 ′, while large apertures 553 ′ are formed through plate member 120 ′ in the spaces between the support members 124 ′.
Preferably, the needle has a raised tip with a convex tip surface, or an otherwise blunt tip 555 , which decreases the tendency of the needle to score the underside of the selected die during actuation of the needle and contact of the needle with the selected die, collectively referred to as “striking” the die. In embodiments of the present invention where striking occurs while the frame, film and sawed wafer assembly (reference character 108 in FIG. 1 a ) is positioned over the base, blunt tip 555 also prevents perforation of carrier film 104 during striking. Perforation of carrier film 104 could came a loss of the vacuum that pulls the film away from the dice 102 . In such embodiments, needles 554 pass through the plate member and/or the screen during striking.
Turning again to FIG. 1 a , the preferred dimensions of frame ring 106 are such that the distance between the outer periphery of wafer 101 and the inner surface of the frame permits the plunge-up head 550 (see FIGS. 6 and 7) to further remove carrier film 104 from the outermost complete dice without contacting the frame.
Preferably, in operation, the plunge-up head does not disrupt the vacuum which pulls portions of the carrier film from the dice. Thus, as FIG. 6 illustrates, a preferred embodiment of base 610 includes an array of base needles 670 a , 670 b , 670 c , etc. therein, each of which are slidingly engaged within needle ports 676 a , 676 b , 676 c , etc., respectively. Needle ports 676 are each formed through plate member 620 . Each base needle 670 includes an actuation end 672 and a needle tip 674 . The activation end 672 of each base needle 670 is preferably exposed to the lower, outer surface of plate member 620 . Preferably, tip 674 of each base needle is raised, with a convex surface, or otherwise blunt to prevent scoring of a selected die 102 a as the needle tip comes into contact with the selected die. Blunt needle tip 674 also prevents perforation of carrier film 104 as needle 670 is actuated, which facilitates maintenance of the vacuum which pulls portions of the film away from selected dice 102 . Preferably, each base needle 670 -needle port 676 assembly is scaled in order to maintain the vacuum which has been created in base 610 . Alternatively, a positive pressure collet could be employed in place of a plunge-up head by directing pressurized air upward against needle 670 to drive the needle against selected die 102 a ,
As an example of the operation of plunge-up head 550 in the present embodiment of base 610 , the plunge-up head is positioned beneath the base needle 670 or base needles located beneath selected die 102 a . As the plunge-up head needle 554 is actuated, it moves upward, contacts actuation end 672 of base needle 670 , and forces the base needle upward against the selected die to further loosen the selected die from carrier film 104 .
With reference to FIG. 7, another preferred embodiment of base 710 includes a scaled plunge-up head housing 780 , within which plunge-up head 550 is disposed. In addition to creating a vacuum within the base, vacuum source 714 creates a vacuum within plunge-up head housing 780 . Plunge-up head 550 is repositionable within housing 780 without disrupting the vacuum therein. Thus, base 710 permits direct contact of needle 554 through plate member 720 and the screen thereon, if any, with selected die 102 a to further remove the selected die from carrier film 104 .
With reference to FIG. 8, another embodiment of the apparatus of the present invention includes a small base 810 , including an uneven film removal surface as described above in reference to FIGS. 1 b , 2 a through 2 e and 3 . Base 810 is positionable beneath a selected die 102 a on a wafer assembly 108 using known apparatus and methods. Base 810 is attachable to a vacuum source (not shown) at connector 812 . A die pick-up mechanism 820 , as described above in reference to FIG. 4, may also be used in connection with positionable base 810 .
In use, positionable base 810 is oriented beneath selected die 102 a and positioned in close proximity to the carrier film attached to the selected die. The vacuum source is actuated, pulling air from the lower areas of the base and removing portions of the carrier film from selected die 102 a , thereby reducing the adhesion of the film to the die. If desired, the vacuum may be applied continuously, the base then sliding laterally to different locations beneath the carrier film. Die pick-up mechanism 820 then completely removes selected die 102 a from the carrier film.
FIG. 8 a shows an alternative embodiment 810 ′ of a positionable base. Base 810 ′ is adapted to fit over a die plunge-up mechanism 830 , having a needle 840 , piston, pressurized air line, or other plunge-up mechanism therein.
Referring again to FIG. 5, as an example of the use of embodiment 500 of die removal mechanism, vacuum head 510 is positioned above a selected die 102 a and plunge-up head 550 is positioned beneath the selected die. Vacuum head 510 is lowered toward selected die 102 a . Plunge-up head 550 is raised to an appropriate position beneath selected die 102 a . Vacuum source 530 is activated to direct a vacuum through vacuum head 510 and at the exposed surface of selected die 102 a . Preferably, while vacuum head 510 is pulling selected die 102 a , needle 554 is actuated by actuator 556 to strike the selected die and further remove carrier film 104 from the selected die. In embodiments of the present method wherein removal of selected die 102 a occurs while wafer assembly 108 is disposed upon the base, each needle 554 passes through the plate member and the screen, if any, during striking. Vacuum head 510 is then raised while holding selected die 102 a , and transfers the selected die to a desired location. When embodiment 610 of the base, discussed above in reference to FIG. 6, is used in the present method, needle 554 contacts actuation end 672 of the appropriate base needle 670 , which contacts carrier film 104 beneath selected die 102 a to further remove the film from the die.
Inexpensive carrier films may be used with the present invention in lieu of those coated with UV-degradable or other expensive adhesives, or adhesives which contaminate the dice. For example, the pressure sensitive adhesive-coated polymer films manufactured by Shinkawa and Nitto, both of Japan, which are used for protectively coating sheet steel, are particularly useful in the invented system. Such films are desirable for use because of their low cost and chemical cleanliness (i.e., will not contaminate dice), both of which advantages provide a reduction in manufacturing costs.
Another consequent advantage of the invention is that the likelihood of dropping, contaminating, fracturing or otherwise damaging the die is much reduced when compared with methods which were previously known in the art.
While the invention has been described in terms of a vacuum drawing the carrier film down and away from the dice supported thereon, those of ordinary skill in the art will recognize that it is a pressure differential which effects movement of the film. Accordingly, it is also contemplated that a higher (positive) pressure may be applied to the top of the carrier film to “push” the film downward against ambient pressure therebelow. Specifically, a push-up head may be employed within a bell-type chamber placed over the frame ring and carrier film to effect withdrawal of large portions of the film from the dice.
Although the foregoing description contains many specificities, these should not be construed as limiting the scope of the present invention, but as merely providing illustrations of some of the presently preferred embodiments. Similarly, other embodiments of the invention may be devised which do not depart from the spirit or scope of the present invention. The scope of this invention is, therefore, indicated and limited only by the appended claims and their legal equivalents, rather than by the foregoing description. Additions, deletions and modifications to the embodiments of the invention as disclosed, and the combination of features of different embodiments, are specifically contemplated as falling within the scope of the invention.
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An apparatus which reduces the surface area with which a carrier film adheres to a die, including a plate member including laterally spaced supports preferably, the apparatus also includes a vacuum source operatively connected to the plate member Upon placement of a carrier film having an array of semiconductor diet adhered thereto onto the plate member, the dice are proximate the supports. The vacuum pulls air from the spaces between the supports, which partially releases the carrier film from the bottom surface of at Least sonic of the dice. The apparatus may also include a die removal mechanism such as a vacuum toilet type die pick-up mechanism, an extendable member die plunge-dip mechanism, or a combination thereof. The present invention also includes a method for reducing the surface area with which a carrier film adheres to a die to facilitate removal thereof.
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REFERENCE TO OTHER APPLICATIONS
This application contains subject matter in common with co-pending application of Wigger and Eggers Ser. No. 355,287, filed Apr. 27, 1973 entitled PROCESS OF REMOVING INSULATION FROM WIRE.
BACKGROUND OF THE INVENTION
Conventionally, insulation is removed from scrap copper wire by burning or by mechanical stripping processes. These have disadvantages particularly with respect to fine copper wire. In the burning process undesirable ecological effects are produced and fine copper wire tends to be oxidized. The stripping process is not particularly satisfactory for smaller wire.
The present invention provides a continuous process for removing a gas producing insulation from an item such as copper wire and particularly for removing insulation containing polyvinyl chloride. This type insulation when subjected to a conventional pyrolysis or vaporization process produces chlorine. The chlorine is produced either as a gas or more likely as hydrochloric acid, as water vapor is present in the products of decomposition or combustion. Both of these are undesirable products from an ecological point of view.
As used in this application the term chlorine includes the gas and the acid form. The present process provides for the reaction of the hydrochloric acid (HCl) with a calcium containing substance such as calcium oxide, calcium carbonate, dolomite (part MgCo 3 and part CaCO 3 ), and the like, to produce calcium chloride as a by-product. The calcium chloride is used by many street and highway departments to apply to snow and ice covered streets and highways. The present process has the advantage that there are not undesirable by-products, and the emissions are conventional such as hot air, nitrogen, water vapor, and carbon dioxide.
Accordingly, one of the principal objects of the present invention is to provide a continuous process for removing insulation containing polyvinyl chloride from items such as copper wire without the formation of undesirable chlorine containing by-products. Another object is to provide an economical process which operates continuously and which produces cleaned copper wire from the process. Still another object is to provide a reaction method whereby copper wire coated with polyvinyl chloride insulation is passed through a heated fluidized bed of small particles of calcium carbonate to decompose the insulation and react the chlorine from the insulation with the calcium carbonate to produce usable calcium chloride.
These and other objects and advantages will become apparent hereinafter.
SUMMARY OF THE INVENTION
This invention comprises a continuous process for removing gas producing insulation from articles, and specifically involves the chemical reaction in a fluidized bed of a calcium compound with chlorine released from chlorine producing insulation to produce useful calcium chloride and eliminate other undesirable by-products. This invention also comprises the use of a fluidized bed reactor after the decomposition of the chlorine containing insulation and combinations of the foregoing processes.
DRSCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic flow diagram of the process of this invention;
FIG. 2 is an enlarged fragmentary vertical sectional view of the fluidized bed reactor;
FIG. 3 is an enlarged fragmentary vertical view of the discharge end of the fluidized bed reactor;
FIG. 4 is a fragmentary horizontal sectional view of the discharge end of the fluidized bed reactor,
FIG. 5 is a fragmentary sectional view taken along lines 5--5 of FIG. 3;
FIG. 6 is a sectional view taken along lines 6--6 of FIG. 4; and
FIG. 7 is a schematic flow diagram of a modification of the process of this invention.
DETAILED DESCRIPTION
The continuous system of this invention (as shown in FIG. 1) comprises a fluid bed decomposition and reaction chamber 10, which includes a wire scrap advancing mechanism 11 (which is shown in FIGS. 2-6 and will be described in detail hereinafter), and a fluidized bed hearth 12; an afterburner 13; an HCl scrubber 14; and an induced draft fan 15. The input material, which preferably is insulated copper wire having polyvinyl chloride insulation, is pre-chopped in a shearing machine (not shown) from its conventional 1500 pound bale form to a size suitable for this process. The chopped wire is continuously fed from the shear to the chamber 10 at a controlled rate by a conveyor 16. The wire preferably is chopped to less than about 6 inches in size in the shearing machine. The chopped wire passes through a water seal 17 which seals the inlet of the decomposition chamber 10 from the atmosphere. The decomposition chamber 10 is divided into a pyrolysis section 53 and a decomposition section 52. The pyrolysis section 53 is provided with a pyrolysis burner 18. The burner 18 normally is gas fired and maintains the first zone or pyrolysis section 53 of the chamber 10 at an operating temperature of about 600°F. with a reducing atmosphere.
A combustion burner 19 operates beneath the bed hearth 12 with reducing gas or excess air to remove the residue in the second zone or combustion section 52 of the chamber 10.
A pilot burner 19A provides mixing and safety ignition to prevent a build-up of combustible atmosphere and resulting explosion within the upper portion of the chamber 10.
A fluidizing air fan 20 keeps the bed 12 in fluidized condition.
The cut feed material is pulled over the hearth 12 by the advancing mechanism 11 through the first section 53 of the chamber 10 where it is subjected to pyrolysis and is decomposed in a controlled atmosphere void of excess oxygen and controlled with respect to analysis and temperature by the burner 18. A calcium based compound is deposited into the top of the chamber 10 from storage 21 by a conveyor 22. The calcium based compound, preferably calcium carbonate, is from about -10 to about -200 mesh in size and is heated in the second portion 52 of the chamber 10 to a temperature sufficient to decompose the insulation on the feed. The feed material generally is heated to a temperature from about 600° to 1200°F. for best decomposition of the insulation.
The calcium carbonate is fluidized by the discharge from the burners 18 and 19 and surrounds the feed while in fluidized condition. The insulation on the feed usually contains polyvinyl chloride insulation which, when decomposed, releases chlorine. The chlorine reacts with the calcium carbonate to produce calcium chloride.
The details of construction of the chamber 10 are shown in FIGS. 2-6. The chamber 10 generally is circular in cross-section as seen in FIGS. 5 and 6. The hearth 12 is positioned in the lower half of the chamber 10 and divides the chamber into upper and lower sections. The hearth 12 is provided with a plurality of openings 50 therethrough which connect the upper chamber 51 and the two lower chambers 52 and 53. The pyrolysis burner 18 is positioned in the plenum chamber 53 in the fluidizing air inlet.
The plenum chamber 53 constitutes a pyrolysis zone and is maintained at about 600°F. Discharges 54 and 54a from the fluidizing air fan 20 supply fluidizing gases to the chambers 53 and 52, respectively. At the end of the upper chamber 51 are the wire scrap inlet 55 and the calcium carbonate inlet 56. The gas in the chambers 52 and 53 passes through the openings 50 to fluidize the calcium carbonate above the chambers 52 and 53.
The scrap is pulled along the hearth 12 by the advancing mechanism 11. The advancing mechanism 11 comprises a rake assembly 57 and a ramp assembly 58. The rake assembly 57 and the ramp assembly 58 are movable independently and in unison.
The ramp assembly 58 comprises a base member 59 positioned in a track 60 mounted at the sides of the furnace 10 (FIG. 6). The base member 59 has spaced cam blocks 61 with inclined faces 62 mounted thereon. The base 59 is attached to a ramp pull rod 64 which is connected to a ramp drive chain 65 and thence to a variable speed reversible motor 66 through a drive axle and gear 65'. A clutch 67 allows the ramp drive to be disconnected from the motor 66. Thus, the base 59 and the cam blocks 61 can be reciprocated longitudinally in the chamber 10 along the tracks 60.
The other part of the advancing mechanism 11 is the rake assembly 57 which consists of parallel side bars 68 which are connected by spaced cross rake members 69 which have downwardly projecting tines 70 depending therefrom (FIGS. 2 and 6). The side bars 68 have inclined surfaces 71 aligned with the inclined surfaces 62 and cutout portions 72. This allows the rake assembly 57 to be reciprocated longitudinally and vertically in the chamber 10 with a rectilinear motion. Thus, the scrap is pulled in a raking action along the hearth 12 as will be more fully explained hereinafter.
The rake assembly 57 has a rake pull 73 connected to a rake drive chain 74 which is connected through a drive pulley 74' to the variable speed reversible motor 66 by a clutch 75 so that the rake drive 74 can be disconnected from the motor 66.
In operation, the rake 57 and the ramp 58 are both at their leftmost position toward the intake end of the chamber 10. This is shown by the broken lines in FIG. 2. The rake side bars 68 have track engaging surfaces 68a on the track 60. The rake tines 70 are in their lowermost position engaged with the scrap on the hearth 12. The ramp assembly 58 and the rake assembly 57 are moved in unison toward the discharge end of the chamber 10 by the motor 66 through the drives 65 and 74 until the rightmost ramp member 61 engages a stop 76. This disengages the clutch 67 and the ramp assembly 58 stops. The rake assembly 57 continues to move up the surfaces 62 and thus moves longitudinally and vertically independently of the ramp assembly 58. This disengages the tines 70 from the scrap on the hearth 10. This is the solid line position shown in FIG. 2.
When the rake assembly 57 engages a stop the motor 66 is reversed, the clutch 67 and 75 are re-engaged, and the rake assembly 57 and the ramp assembly 58 are moved leftward in unsion toward the intake end of the chamber 10. When the ramp assembly 58 and the rake assembly 57 are in their leftmost position, the motor 66 again is reversed and the rake clutch 75 is disengaged so that the ramp assembly 58 is moved rightwardly or toward the discharge end of the bed 12 independently of the rake assembly 57. This causes the rake assembly to drop vertically so that the rake tines 70 are in engagement with the feed on the bed 12. When the rake drive clutch 75 is re-engaged, the rake assembly 57 is moved rightwardly toward the discharge end of the bed 12 in concert with the ramp assembly 58 to move feed lineally along the hearth 12.
The foregoing cycle is repeated to move the scrap along the hearth 12 by the rightward movement of the tines 70 while in their lowermost position.
As the feed is moved along the bed 12 by the ramp 58 and rake 57, it is surrounded and engaged by the heated particles of calcium carbonate which is fluidized as hereinbefore explained. The heated calcium carbonate engages and decomposes the insulation on the feed as the feed moves along the bed 12. Some of the calcium carbonate reacts with the chlorine or hydrochloric acid produced from the insulation to produce calcium chloride in the chamber 10.
The calcium carbonate material flows across the bed to a weir 23 (FIG. 5) where it is discharged from the chamber 10 and collected in a receiver at 24. The calcium chloride is in the fines which falls over the weir 23 to provide constant removal of a mixed dust of calcium carbonate and calcium chloride. The removal of product is through a rotary air lock feeder 25.
The product collected at 24 is about 10% to about 12% calcium chloride and about 88 to about 90% calcium carbonate.
As mentioned the insulation on the feed material is removed as the feed moves through the chamber 10 on the bed 12. The clean copper wire leaves the decomposition chamber 10 through an exit water seal 26 which also acts as a quench for the wire scrap, thereby cooling and further cleaning the product. The product from the water seal 26 is collected in a receptacle 27 or a bailer for further handling.
The quench tank 26 also is used to dewater and collect any solid calcium carbonate which has been carried over with the wire or which is deposited therein from the HCl scrubber 14 as will be hereinafter explained in more detail. The dewatering device 28 is conventional in the art.
The gases and smoke generated during decomposition in the chamber 10 may contain small amounts of chlorine dependent on the efficiency of the bed reaction. The products of decomposition and any chlorine pass into the afterburner 13 where all of the remaining combustible products are consumed. The afterburner includes a burner 29 and an excess combustion air inlet 30.
The burned gases from the after burner 13 may still contain chlorine as well as the products of combustion. The products of combustion, including the chlorine, from the afterburner 13 are passed through an HCl scrubber 14 where the remaining chlorine and the dust is removed.
The scrubber 14 is of a conventional bubble plate-type and the water on the plates contains CaCO 3 so that any chlorine in the gas is neutralized and reacted to form CaCl 2 . The entering gas is cooled with a water spray containing suspended particles of the calcium carbonate at 31. Water containing the CaCl 2 dissolved therein is withdrawn from the scrubber 14 at a pump 32 and sprayed at 33 over the wire leaving the quench tank 26. The CaCl 2 stays in solution in the quench tank 26. Some of the solution is bled into the chamber 10 for temperature control where the solids are recovered at 24. Some CaCl 2 is also introduced into the chamber 10 with the dewatered CaCO 3 , and recovered at 24.
The scrubber 14 also removes any dust such as CaCO 3 dust, which also passes through the quench tank 26 and via the dewatering device 28 to the CaCO 3 storage 21.
From the top of the scrubber 14 are passed the gases free of dust and chlorine. These gases pass through the induced draft fan 15 which provides the pressure differential causing the gases to flow through the system. From the fan 15 the cleaned gases are discharged to the atmosphere through a stack 34.
An emergency by-pass 35 connects the afterburner discharge to the stack 34.
A specific example of the system is designed to process 3000 pounds of material per hour. This system generates 6500 cubic feet per minute of burned gases to the HCl scrubber 14. The afterburner 13 operates at 1600°F. and the decomposition chamber 10 at 1000°F.
MODIFICATION
A modification of the process of this invention is shown in FIG. 7. This system comprises a decomposition chamber 100 including an afterburner 111, a fluidized bed reactor 112, a dust collector 113, and an induced draft fan 114. The chopped input material (usually insulated copper wire containing polyvinyl chloride insulation) is continuously fed at a rate controlled by a conveyor 115 through a water trap 116 to the chamber 100.
The cut feed material is moved on the bed 119 by a conveying means 119A similar to the conveying means 11 of FIGS. 1-6, through the decomposition chamber 100 where it is ignited and decomposed in a controlled atmosphere void of excess oxygen and controlled with respect to analysis and temperature by the burners 117. The feed material generally is heated to a temperature from about 600 to 1200°F. for best decomposition.
The insulation on the feed material decomposes and burns in the decomposition chamber 100. The clean copper wire leaves the decomposition chamber 100 through an exit water seal 120 which also acts as a quench for the wire scrap, thereby cooling and further cleaning the product. The product from the water seal 120 is collected in a receptacle 121 or a bailer for further handling.
The gases and smoke generated during decomposition, which contain chlorine, pass into an afterburner 111 where all of the remaining combustible product are consumed. The afterburner includes a burner 122 and an excess combustion air inlet 123.
The burned gases from the afterburner 111 still contain chlorine as well as the products of combustion. The products of combustion, including the chlorine from the afterburner 111, are passed through a fluidized bed reactor 112 where the fluidized bed material is a calcium containing substance in a granular form of about -10 to about -200 mesh. The substance preferably is calcium carbonate (CaCO 3 ). The gases from the afterburner 111 act as the fluidizing medium. The intimate contact of the exhaust gases with the calcium carbonate causes a chemical reaction to take place in which the chlorine is reacted with the calcium carbonate to produce calcium chloride. This is similar to that described for the structure of FIGS. 1-6.
The calcium carbonate is deposited in a conveyor 124 where it is carried to a hopper 125 and then passed through a rotary air lock feeder 126 to the fluidized bed reactor 112. The same passes across the bed in fluidized condition to the exit rotary air lock 127. The air lock feeder 126 controls feed of make-up calcium carbonate to the reactor 112 to replace that consumed in the reaction.
From the fluidized bed reactor 112 the gases, less the chlorine, are passed through the mechanical dust collector 113 and then exit through the induced draft fan 114 which provides the pressure differential to flow the gases through the entire system.
A further modification of the system combines the features of FIGS. 1-6 and FIG. 7 and uses a secondary fluidized bed converter to remove any chlorine not reacted in the primary fluidized bed converter.
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This application describes a continuous method of removing polyvinyl chloride insulation or other volatilizable material from items such as copper wire without producing undesirable by-products. The method involves the pyrolysis of the insulation on the wire in a fluidized bed reactor charged with small particles of calcium carbonate. The calcium carbonate reacts with the gaseous chlorine from the insulation to produce calcium chloride which then is collected and can be used for snow removal, road construction, and the like. After removal of the insulation, the copper wire is cooled and cleaned. The products of combustion are passed through an afterburner to a HCl scrubber containing CaCO 3 where any remaining chlorine is reacted with calcium carbonate to produce CaCl 2 . The application also describes apparatus for moving the items across the heated reactor. An alternative process involves pyrolysis of the insulation in a pyrolysis chamber, passing the products of pyrolysis through an afterburner and thence to a fluidized bed reactor which uses fluidized particles of CaCO 3 to remove any chlorine from the products of combustion of the afterburner. An HCl scrubber is also used as a final processing step in this form of the process to remove particulate matter and to prevent HCl emissions in the event of a system failure.
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BACKGROUND OF THE INVENTION
Field of the Invention
This invention relates to tissue ablation systems. More particularly, this invention relates to monitoring of contact between an invasive probe and tissue within the body.
Description of the Related Art
Cardiac arrhythmias, such as atrial fibrillation, occur when regions of cardiac tissue abnormally conduct electric signals to adjacent tissue, thereby disrupting the normal cardiac cycle and causing asynchronous rhythm.
Procedures for treating arrhythmia include surgically disrupting the origin of the signals causing the arrhythmia, as well as disrupting the conducting pathway for such signals. By selectively ablating cardiac tissue by application of energy via a catheter, it is sometimes possible to cease or modify the propagation of unwanted electrical signals from one portion of the heart to another. The ablation process destroys the unwanted electrical pathways by formation of non-conducting lesions.
Verification of physical electrode contact with the target tissue is important for controlling the delivery of ablation energy. Attempts in the art to verify electrode contact with the tissue have been extensive, and various techniques have been suggested. For example, U.S. Pat. No. 6,695,808 describes apparatus for treating a selected patient tissue or organ region. A probe has a contact surface that may be urged against the region, thereby creating contact pressure. A pressure transducer measures the contact pressure. This arrangement is said to meet the needs of procedures in which a medical instrument must be placed in firm but not excessive contact with an anatomical surface, by providing information to the user of the instrument that is indicative of the existence and magnitude of the contact force.
As another example, U.S. Pat. No. 6,241,724 describes methods for creating lesions in body tissue using segmented electrode assemblies. In one embodiment, an electrode assembly on a catheter carries pressure transducers, which sense contact with tissue and convey signals to a pressure contact module. The module identifies the electrode elements that are associated with the pressure transducer signals and directs an energy generator to convey RF energy to these elements, and not to other elements that are in contact only with blood.
A further example is presented in U.S. Pat. No. 6,915,149. This patent describes a method for mapping a heart using a catheter having a tip electrode for measuring local electrical activity. In order to avoid artifacts that may arise from poor tip contact with the tissue, the contact pressure between the tip and the tissue is measured using a pressure sensor to ensure stable contact.
U.S. Patent Application Publication 2007/0100332 describes systems and methods for assessing electrode-tissue contact for tissue ablation. An electro-mechanical sensor within the catheter shaft generates electrical signals corresponding to the amount of movement of the electrode within a distal portion of the catheter shaft. An output device receives the electrical signals for assessing a level of contact between the electrode and a tissue.
U.S. Pat. No. 7,306,593, issued to Keidar et al., describes a method for ablating tissue in an organ by contacting a probe inside the body with the tissue to be ablated, and measuring one or more local parameters at the position using the probe prior to ablating the tissue. A map of the organ is displayed, showing, based on the one or more local parameters, a predicted extent of ablation of the tissue to be achieved for a given dosage of energy applied at the position using the probe. The given dosage of energy is applied to ablate the tissue using the probe, and an actual extent of the ablation at the position is measured using the probe subsequent to ablating the tissue. The measured actual extent of the ablation is displayed on the map for comparison with the predicted extent.
Impedance-based methods for assessing catheter-tissue contact that are known in the art typically rely on measurement of the magnitude of the impedance between an electrode on the catheter and a body-surface electrode. When the magnitude is below some threshold, the electrode is considered to be in contact with the tissue. This sort of binary contact indication may be unreliable, however, and is sensitive to changes in the impedance between the body-surface electrode and the skin.
U.S. Patent Application Publication Nos. 2008/0288038 and 2008/0275465, all by Sauarav et al., which are herein incorporated by reference, describe an electrode catheter system may comprise an electrode adapted to apply electric energy. A measurement circuit adapted to measure impedance may be implemented between the electrode and ground as the electrode approaches a target tissue. A processor or processing units may be implemented to determine a contact condition for the target tissue based at least in part on reactance of the impedance measured by the measurement circuit. In another embodiment, the contact condition may be based on the phase angle of the impedance.
SUMMARY OF THE INVENTION
There is provided according to embodiments of the invention a method of ablation, which is carried out by inserting a probe having an ablation electrode into a body of a living subject, and while the ablation electrode is in a non-contacting relationship to a target tissue, making a pre-contact determination of a phase of an electrical current passing between the ablation electrode and another electrode. The method is further carried out by urging the ablation electrode into a contacting relationship with the target tissue, and while the ablation electrode is in the contacting relationship applying a dosage of energy via the ablation electrode to the target tissue for ablation thereof, iteratively making intra-operative determinations of the phase of the electrical current. The method is further carried out by establishing that one of the intra-operative determinations satisfies a termination criterion for completion of the ablation, and responsively thereto, terminating the energy application.
One aspect of the method includes displaying a visual indication of the intra-operative determinations of the phase of the electrical current. The visual indication may include a progress display of the ablation with respect to an intended lesion in the target tissue.
According to yet another aspect of the method, the termination criterion includes a difference between one of the intra-operative determinations and the pre-contact determination that is less than a predetermined value.
According to still another aspect of the method, the termination criterion includes a failure of one of the intra-operative determinations to vary from a preceding one of the intra-operative determinations by more than a threshold value.
According to an additional aspect of the method, making the pre-contact determination and the intra-operative determinations comprise measuring a phase of an impedance between an electrode on the probe and a body-surface electrode.
According to one aspect of the method, making the pre-contact determination and the intra-operative determinations includes making a comparison with respective phases of a reference waveform taken from a reference electrode that is spaced apart from the target tissue.
In a further aspect of the method, making intra-operative determinations is performed every 2-5 seconds.
In yet another aspect of the method, making intra-operative determinations and applying a dosage of energy are performed concurrently.
According to still another aspect of the method, making a pre-contact determination is performed at a power of less than 10 milliwatts.
According to an additional aspect of the method, making intra-operative determinations is performed at a power of 5-50 watts.
Other embodiments of the invention provide apparatus for carrying out the above-described method.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
For a better understanding of the present invention, reference is made to the detailed description of the invention, by way of example, which is to be read in conjunction with the following drawings, wherein like elements are given like reference numerals, and wherein:
FIG. 1 is a pictorial illustration of a system for performing ablative procedures on a heart of a living subject, which is constructed and operative in accordance with an embodiment of the invention;
FIG. 2 is a composite drawing illustrating phase relationships of currents passing through an electrode of the catheter as it moves into contact with heart tissue in accordance with an embodiment of the invention; and
FIG. 3 is a flow chart of a method of tissue ablation in accordance with an embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
In the following description, numerous specific details are set forth in order to provide a thorough understanding of the various principles of the present invention. It will be apparent to one skilled in the art, however, that not all these details are necessarily always needed for practicing the present invention. In this instance, well-known circuits, control logic, and the details of computer program instructions for conventional algorithms and processes have not been shown in detail in order not to obscure the general concepts unnecessarily.
Aspects of the present invention may be embodied in software programming code, which is typically maintained in permanent storage, such as a computer readable medium. In a client/server environment, such software programming code may be stored on a client or a server. The software programming code may be embodied on any of a variety of known non-transitory media for use with a data processing system, such as a diskette, hard drive, electronic media or CD-ROM. The code may be distributed on such media, or may be distributed to users from the memory or storage of one computer system over a network of some type to storage devices on other computer systems for use by users of such other systems.
Turning now to the drawings, reference is initially made to FIG. 1 , which is a pictorial illustration of a system 10 for performing ablative procedures on a heart 12 of a living subject, which is constructed and operative in accordance with a disclosed embodiment of the invention. The system comprises a catheter 14 , which is percutaneously inserted by an operator 16 through the patient's vascular system into a chamber or vascular structure of the heart 12 . The operator 16 , who is typically a physician, brings the catheter's distal tip 18 into contact with the heart wall at an ablation target site. Optionally, Electrical activation maps may then be prepared, according to the methods disclosed in U.S. Pat. Nos. 6,226,542, and 6,301,496, and in commonly assigned U.S. Pat. No. 6,892,091, whose disclosures are herein incorporated by reference. One commercial product embodying elements of the system 10 is available as the CARTO® 3 System, available from Biosense Webster, Inc., 3333 Diamond Canyon Road, Diamond Bar, Calif. 91765.
Areas determined to be abnormal, for example by evaluation of the electrical activation maps, can be ablated by application of thermal energy, e.g., by passage of radiofrequency electrical current through wires in the catheter to one or more electrodes at the distal tip 18 , which apply the radiofrequency energy to the myocardium. The energy is absorbed in the tissue, heating it to a point (typically about 50° C.) at which it permanently loses its electrical excitability. When successful, this procedure creates non-conducting lesions in the cardiac tissue, which disrupt the abnormal electrical pathway causing the arrhythmia. The principles of the invention can be applied to different heart chambers to treat many different cardiac arrhythmias.
The catheter 14 typically comprises a handle 20 , having suitable controls on the handle to enable the operator 16 to steer, position and orient the distal end of the catheter as desired for the ablation. To aid the operator 16 , the distal portion of the catheter 14 contains position sensors (not shown) that provide signals to a positioning processor 22 , located in a console 24 .
Ablation energy and electrical signals can be conveyed to and from the heart 12 through one or more ablation electrodes 32 located at or near the distal tip 18 via cable 34 to the console 24 . Pacing signals and other control signals may be conveyed from the console 24 through the cable 34 and the electrodes 32 to the heart 12 . Sensing electrodes 33 , also connected to the console 24 are disposed between the ablation electrodes 32 and have connections to the cable 34 .
Wire connections 35 link the console 24 with body surface electrodes 30 and other components of a positioning sub-system. The electrodes 32 and the body surface electrodes 30 may be used to measure tissue impedance at the ablation site as taught in U.S. Pat. No. 7,536,218, issued to Govari et al., which is herein incorporated by reference. A temperature sensor (not shown), typically a thermocouple or thermistor, may be mounted on or near each of the electrodes 32 .
The console 24 typically contains one or more ablation power generators 25 . The catheter 14 may be adapted to conduct ablative energy to the heart using any known ablation technique, e.g., radiofrequency energy, ultrasound energy, and laser-produced light energy. Such methods are disclosed in commonly assigned U.S. Pat. Nos. 6,814,733, 6,997,924, and 7,156,816, which are herein incorporated by reference.
The positioning processor 22 is an element of a positioning system 26 of the system 10 that measures location and orientation coordinates of the catheter 14 .
In one embodiment, the positioning system 26 comprises a magnetic position tracking arrangement that determines the position and orientation of the catheter 14 by generating magnetic fields in a predefined working volume its vicinity and sensing these fields at the catheter using field generating coils 28 and may include impedance measurement, as taught, for example in U.S. Patent Application Publication No. 2007/0060832, which is herein incorporated by reference. The positioning system 26 may be enhanced by position measurements using the impedance measurements described in the above-noted U.S. Pat. No. 7,536,218.
As noted above, the catheter 14 is coupled to the console 24 , which enables the operator 16 to observe and regulate the functions of the catheter 14 . Console 24 includes a processor, preferably a computer with appropriate signal processing circuits. The processor is coupled to drive a monitor 29 . The signal processing circuits typically receive, amplify, filter and digitize signals from the catheter 14 , including signals generated by the above-noted sensors and a plurality of location sensing electrodes (not shown) located distally in the catheter 14 . The digitized signals are received and used by the console 24 and the positioning system 26 to compute the position and orientation of the catheter 14 and to analyze the electrical signals from the electrodes.
Typically, the system 10 includes other elements, which are not shown in the figures for the sake of simplicity. For example, the system 10 may include an electrocardiogram (ECG) monitor, coupled to receive signals from one or more body surface electrodes, so as to provide an ECG synchronization signal to the console 24 . As mentioned above, the system 10 typically also includes a reference position sensor, either on an externally-applied reference patch attached to the exterior of the subject's body, or on an internally-placed catheter, which is inserted into the heart 12 maintained in a fixed position relative to the heart 12 . Conventional pumps and lines for circulating liquids through the catheter 14 for cooling the ablation site are provided.
Embodiments of the present invention measure the phase of the impedance between the catheter electrode and the body-surface electrode. This phase shifts markedly with distance between the catheter electrode and the tissue over the range of about 1-2 mm, between contact and non-contact, due to the attendant change in the capacitance between the electrode and the tissue. It thus provides a sensitive measure of short-range distance and contact.
Reference is now made to FIG. 2 , which is a composite drawing illustrating phase relationships of currents passing through an electrode of the catheter 14 as it moves into contact with wall 37 of heart 12 ( FIG. 1 ) in accordance with an embodiment of the invention. A reference electrode 39 is optionally provided for this purpose. The reference electrode 39 does not contact the wall 37 . The electrodes are driven with a signal at a known frequency, which passes through the tissue and is received by the body surface electrodes 30 ( FIG. 1 ) or some other receiving electrode. Waveforms at the right side of FIG. 2 include, from top to bottom, a reference waveform 41 taken from the reference electrode 39 , a pre-contact waveform 43 from the ablation electrode 32 , taken when the ablation electrode 32 is out of contact with the wall 37 , a contact waveform 45 , taken when the ablation electrode 32 is in mechanical contact with the wall 37 , and a post-ablation waveform 47 , following completion of ablative therapy but while the ablation electrode 32 is still in contact with the wall 37 .
Phase shifts are indicated by displacement of vertical lines 49 , 51 drawn through corresponding maxima of the pre-contact waveform 43 and the contact waveform 45 . The phase shifts occur when the ablation electrode 32 is brought into contact with the wall 37 . The inventors have discovered that phase measurement of this sort can be used not only to verify tissue contact, but also to check the progress of ablation: as the lesion is created and while the ablation electrode 32 maintains contact with the tissue, the phase of the impedance between the ablation electrode 32 and the tissue changes. Alternatively, the change in the phase between the ablation electrode 32 and the tissue can be determined by any of the other phase determination methods described in the above mentioned U.S. Patent Application Publication Nos. 2008/0288038 and 2008/0275465. The appearance of a waveform approximating post-ablation waveform 47 gives an indication that the tissue has been ablated.
During the ablation, persistent contact between the ablation electrode 32 and the wall 37 may be confirmed using a position sensor in conjunction with the positioning processor 22 ( FIG. 1 ), or by any of the other techniques described above for verifying physical electrode contact with the target tissue.
It should be noted that the phase of the signal received from the reference electrode 39 does not change substantially as the tip electrode makes contact with the tissue. The reference electrode 39 may therefore be used as a basis for measuring the phase shift of the current passing through the ablation electrode 32 or another tip electrode (not shown). The ablator can operate while concurrently monitoring the phase shift. It is not necessary to interlace the two operations.
Reference is now made to FIG. 3 , which is a flow chart of a method of tissue ablation in accordance with an embodiment of the invention. At initial step 53 a catheter, constructed in accordance with one of the above-described embodiments, is introduced into the heart, and an ablation electrode, together with its associated temperature sensor, positioned near a target site using the positioning system 26 ( FIG. 1 ).
Next, at step 55 a reading is taken to obtain the phase of a pre-contact waveform. This may be done by operating the ablation electrode 32 ( FIG. 2 ) in a calibration mode. Optionally, the phase of the pre-contact waveform is related to a waveform read from a reference electrode. In either case, the results are memorized.
Next at step 57 , mechanical contact between the ablation electrode 32 and the wall 37 is verified, using any of the aforementioned methods.
Next, at step 59 a baseline contact waveform is obtained and memorized.
Next, at step 61 , the ablation electrode is activated to ablate the target tissue.
Next, at step 63 , after an interval that may vary according to the lesion desired and the judgment of the operator, an intra-operative waveform is obtained and its phase angle with respect to the baseline contact waveform or the reference waveform ascertained. The phase angle of the intra-operative waveform and a calculated estimation of the degree of completion of the intended lesion may be displayed for the operator. When the rate of change of the phase angle approaches zero, it may be inferred that changes in the tissue are no longer occurring and that the ablation is essentially complete.
Typically, the phase angle is determined every few seconds, e.g., every 2-5, seconds, depending on the stability of the measurement.
The power requirement for obtaining phase angle readings is a less than 10 milliwatts if the ablator is idle. If the ablator is active then 5-50 watts is required.
Control now proceeds to decision step 65 , where it is determined if a termination criterion has been met. Termination criteria that may apply are, for example:
(1) an absence of change in the phase angle over a time interval;
(2) a return of the phase angle of the intra-operative waveform to that of the pre-contact waveform; and
(3) failure of the phase angle to shift more than a threshold amount, e.g., 50% in comparison to an intra-operative waveform obtained in a previous iteration of a loop including steps 61 , 63 .
If a termination criterion has not been met at decision step 65 , then control returns to step 61 . Otherwise control proceeds to final step 67 , where the procedure is terminated.
It will be appreciated by persons skilled in the art that the present invention is not limited to what has been particularly shown and described hereinabove. Rather, the scope of the present invention includes both combinations and subcombinations of the various features described hereinabove, as well as variations and modifications thereof that are not in the prior art, which would occur to persons skilled in the art upon reading the foregoing description.
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Methods and systems achieve tissue ablation, which is carried out by inserting a probe having an ablation electrode into a body of a living subject, and while the ablation electrode is in a non-contacting relationship to a target tissue, making a pre-contact determination of a phase of an electrical current passing between the ablation electrode and another electrode. The ablation electrode is placed in contact with the target tissue, and while the ablation electrode is in the contacting relationship, a dosage of energy is applied via the ablation electrode to the target tissue for ablation thereof. Iterative intra-operative determinations of the phase of the electrical current are made. When one of the intra-operative determinations satisfies a termination criterion, the energy application is terminated.
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BACKGROUND OF THE INVENTION
[0001] The present application relates generally to steam turbines, and more particularly, to systems for reducing the level of erosion experienced by steam turbine components.
[0002] Low-pressure steam turbines are typically driven by wet steam, the moisture content of which may have the form of water film or water droplets. This moisture causes efficiency losses and potential erosion of steam turbine components. This erosion is most prominent in steam turbine airfoils/blades as the moisture content of the steam impacts the nozzles (stationary airfoils) or buckets (rotating airfoils). The erosion is even more exaggerated in some last stages of steam turbines, where speed and local wetness values are highest.
[0003] Several solutions have been proposed to reduce the amount and/or size of water droplets accumulated on steam turbine components. One solution adds radial grooves close to the leading edge of rotating airfoils to remove the deposited moisture. These grooves, however, only remove moisture that has already caused significant efficiency losses to the rotating airfoils and upstream stationary airfoils. Other solutions rely on protective measures, which include water removal through water drainage arrangements in outer sidewalls (end walls) of the nozzle; or through suction slots made in hollow stator airfoils. This moisture is then collected in circumferential cavities between the diaphragm and the casing and drained to a condenser.
[0004] These moisture removal concepts are based on extraction of moisture film from blade surfaces, through slots, driven by the pressure drop between the steam path and the hollow blade inner space. This pressure drop causes a significant amount of steam to pass through the hollow stator blades and into the condenser. This decreases the steam turbine efficiency.
[0005] Another recently developed technique extracts moisture from blade surfaces through multiple extraction bores in the airfoils. There, the extracted moisture is led to an external steam/moisture separator, the separated water is drained, and the steam is returned back to the main steam path through a steam injection bore located in the center of the pressure side. This technique provides moisture removal as well as steam reinsertion into the steam path, thus improving steam turbine efficiency. There remains, however, room for improvement in providing further structures aimed at reducing blade erosion.
[0006] As a result, there is a desire for improved systems for efficiently and cost effectively reducing moisture-related issues in steam turbine components, such as efficiency losses and potential erosion.
BRIEF DESCRIPTION OF THE INVENTION
[0007] The present application describes a system for removing moisture from a steam/water mixture engaging a stationary component of a steam turbine. The system includes an airfoil, which is disposed in a group of airfoils located within a flow path of a steam turbine. The airfoil is configured for removing moisture from a steam/water mixture traveling in the flow path. Here, the airfoil includes a first and second longitudinal ends and an outer peripheral wall that integrates the first and second longitudinal ends. The first and second longitudinal ends and the outer peripheral wall collectively define a leading edge, a trailing edge, a suction-side face, and a pressure-side face of the airfoil. The airfoil further includes an extraction cavity laterally extending between a portion of the leading edge and a portion of the trailing edge; the extraction cavity comprising an inlet opening in flow communication with the flow path, and an outlet opening in flow communication with the flow path. Moreover, the airfoil includes a cavity configured for separating the steam/water mixture into steam and water, which extends longitudinally within at least a portion of the airfoil. The cavity comprises a top end integrated with the extraction cavity, and a bottom end configured for allowing water to exit the airfoil. As the steam/water mixture travels in the flow path, the inlet opening draws in a portion of the steam/water mixture. A pressure drop across the leading edge and the trailing edge then allows for the portion of the steam/water mixture to enter the cavity. Density differences of the steam and water allow the water to separate from the steam. The separated water flows towards the bottom end, and the steam flows through the outlet opening and returns to the steam path.
[0008] These and other features of the present application will become apparent upon review of the following detailed description of the preferred embodiments when taken in conjunction with the drawings and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a schematic cross-sectional view of a portion of a steam turbine stage illustrating steam and moisture flow there through.
[0010] FIG. 2 is a schematic illustrating an isometric view of an airfoil, in accordance with an embodiment of the present invention.
[0011] FIG. 3 is a top sectional view of the airfoil of FIG. 2 , illustrating the flow path through the airfoil, in accordance with an embodiment of the present invention.
[0012] FIG. 4 is a schematic top view of an airfoil having multiple inlet openings, in accordance with an alternate embodiment of the present invention.
[0013] FIG. 5 is a schematic isometric view of an airfoil having multiple openings, in accordance with another alternate embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0014] The following terms used in the description are defined as follows. The terms “downstream” and “upstream” indicate a direction relative to the flow of working fluid through the steam turbine. As such, the term “downstream” means the direction of the flow, and the term “upstream” means in the opposite direction of the flow through the steam turbine. Related to these terms, the terms “aft” and/or “trailing edge” refer to the downstream direction, the downstream end and/or in the direction of the downstream end of the component being described. Moreover, the terms “forward” or “leading edge” refer to the upstream direction, the upstream end and/or in the direction of the upstream end of the component being described.
[0015] FIG. 1 is a schematic cross-sectional view of a portion of a steam turbine stage illustrating steam and moisture flow there through. FIG. 1 illustrates a portion of a steam turbine stage illustrating the steam and moisture flow through the various stage components. A steam turbine stage generally include two rows of interspersed airfoils—one row of stationary airfoils 102 and the other of rotating airfoils 104 , with the rotating airfoils 104 disposed downstream of the stationary airfoils 102 . The stationary airfoils 102 (sometimes referred to as nozzles) can direct the steam onto the rotating airfoils 104 (sometimes referred to as buckets) to cause the rotating airfoils 104 to rotate with a speed corresponding to the steam pressure. Together, a set of stationary airfoils 102 and a set of rotating airfoils 104 form a steam turbine stage, and the steam turbine may include multiple such stages.
[0016] In low-pressure steam turbines, some of the steam may nucleate to form moisture droplets, referred to as primary droplets 106 , which can be very small (typically less than 0.2 micron). As illustrated in FIG. 1 , these primary droplets 106 generally follow the main steam path (depicted generally at 108 ); However, due to inertial and turbulent deposition, some primary droplets 106 can deposit on the nozzle surfaces in the form of water films or rivulets and may travel downstream to the trailing edge 112 of the nozzle. Additionally, since the main steam path 108 is turning inside the airfoil channel, the centrifugal force will push the droplets towards the pressure side face 114 of the airfoil. These droplets will also accumulate near the trailing edge 112 of the pressure side face of the airfoil; forming water films and rivulets that travel downstream to the trailing edge 112 . On reaching the trailing edge 112 , these water films or rivulets tend to liberate from the stationary airfoil 102 and may form relatively larger secondary droplets 116 (as large as 100-300 microns).
[0017] Secondary droplets 116 may be accelerated by the main steam path 108 , and due to size, may lag behind the main steam path 108 . The secondary droplets 116 , moving slower than the surrounding steam, may reach the downstream rotating airfoils 104 and impact the suction side (convex side) of the leading edge 118 . This moisture impact may cause potential erosion and efficiency losses in the steam turbine.
[0018] To reduce the erosion effects on the rotating blades and to improve steam turbine efficiency, an embodiment of the present invention provides an improved airfoil 200 . FIG. 2 is a schematic illustrating an isometric view of an airfoil 200 , in accordance with an embodiment of the present invention. In one embodiment, the airfoil 200 may be a stationary airfoil, which may be interspersed in a set of airfoils, or the airfoil 200 may be a first stage stationary airfoil. The airfoil 200 may be located within a low-pressure steam turbine, as seen in FIG. 2 , in which the main steam path 202 is indicated by dotted lines, and hashed lines indicate the moisture path 204 . The airfoil 200 may generally be described as having two longitudinal ends and a peripheral wall, defining a leading edge 206 , a trailing edge 208 , a pressure-side face 210 , and a suction-side face 212 .
[0019] An embodiment of the airfoil 200 may include at least one opening 218 to draw in moisture from the airfoil 200 surface. Some steam may also escape with the moisture; to return this steam to the main steam path 202 , the airfoil 200 may include a cavity 214 that separates the moisture from the steam, drains the moisture, and returns dry steam to the main steam path 202 . This feature of the cavity 214 may increase the steam turbine efficiency. The cavity 214 may extend longitudinally through at least a portion of the length of the airfoil 200 . The top end of the cavity 214 may be integrated with the top end surface of the airfoil 200 , while the bottom end of the cavity 214 may include a moisture draining facility 216 . The moisture draining facility 216 may be connected to an external condenser. This may allow the drained water to flow to the condenser for further use. The moisture draining facility 216 from each airfoil 200 may be connected to a circumferential cavity in the diaphragm outer ring, or the inner ring, that provides water collected from the airfoil 200 to the external condenser. In an alternate embodiment, the airfoil 200 may be hollow and not integrated with condenser. In an alternate embodiment of the present invention, the moisture draining facility 216 may discharge to a common receiver 500 , as illustrated in FIG. 5 .
[0020] One or more inlet openings 218 and outlet openings 220 connecting the airfoil surface to the cavity 214 may extract moisture from the surface of the airfoil 200 and re-introduce the dry steam into the main steam path 202 , respectively. Moreover, the inlet openings 218 and outlet openings 220 may include multiple openings or a single longitudinally extending cavity, depending on the application. FIG. 2 depicts one embodiment of the inlet openings where the inlet opening 218 may connect the cavity 214 to the outer surface of the leading edge 206 . The inlet opening 218 may extend longitudinally along at least a portion of the leading edge 206 . The inlet opening may be in flow communication with the main steam path 202 . This inlet opening 218 may extend from the outer surface of the leading edge 206 to the cavity 214 .
[0021] The location of the inlet openings 218 may be based on pressure distribution across the airfoil 200 . A single inlet opening 218 may be located at any position on the airfoil 200 that allows moisture extraction, such as the leading edge 206 , the pressure-side face 210 , or the suction-side face 212 . If the airfoil 200 includes multiple inlet openings 218 , the location of the inlet openings 218 on the airfoil surface may be selected to minimize the pressure difference between the multiple inlet openings 218 . Maintaining a minimum pressure difference between the inlet openings 218 may ensure that steam entering from one inlet opening 218 does not exit from another inlet opening 218 . For example, but not limiting of, the inlet openings 218 may be located on the airfoil surface in regions of maximum moisture impact having similar pressure values.
[0022] The outlet openings 220 , similarly, may be positioned based on the pressure distribution across the airfoil 200 . The outlet opening 220 may be at a lower pressure level than that of the inlet openings 218 , so that steam moves toward the low-pressure area and exits the airfoil 200 . The trailing edge 208 typically has the lowest pressure value on the airfoil 200 ; and in one embodiment, the outlet opening 220 may be positioned near the trailing edge 208 . The outlet opening 220 may extend from the cavity 214 to the surface of the trailing edge 208 . The outlet opening 220 may also extend longitudinally along at least a portion of the trailing edge 208 . The outlet opening 220 may also be in flow communication with the main steam path 202 . In other embodiments, the outlet opening 220 may be positioned at a relatively lower pressure region than the inlet openings 218 . In FIG. 2 , embodiments of the inlet opening 218 and outlet opening 220 are illustrated as single elongated slots extending along the airfoil edges.
[0023] The inlet opening 218 , which may be located on the leading edge 206 , may draw in the water film/droplets due to a pressure difference between the main steam path 202 and the cavity 214 . The structure of the passage between the inlet opening 218 and the outlet opening 220 may induce a negative pressure at the trailing edge 208 of the airfoil 200 . That effect, combined with the relatively high pressure at the inlet opening 218 , may produce a net pressure drop across the airfoil 200 , inducing a general flow towards the trailing edge 208 . Consequently, steam (from the main steam path 202 ) may also be drawn into the cavity 214 through the inlet opening 218 . After the steam-water mixture enters the cavity 214 , water may naturally separate from the mixture. This effect may occur because of the velocity decrease associated with the effect of relatively larger cavity size 214 .
[0024] Gravity acts on the low-velocity steam-water mixture; and the denser water, naturally separates from the mixture, and may be collected at the bottom of the cavity 214 . The remaining steam may flow towards the trailing edge 208 (as the pressure at the trailing edge 208 may be the lower). This steam may be re-introduced to the main steam path 202 via the outlet opening 220 . Here, the outlet opening 220 may be relatively narrower than the cavity 214 , and thus the velocity of the dry steam may increase prior to reentering the main steam path 202 . The dry steam exiting the trailing edge 208 may reduce the size of secondary droplets 116 , accumulated near the trailing edge 208 . The dry exiting steam may energize the moisture film accumulated on the surface of the airfoil 200 , reducing the size of the droplets, thus reducing the effect of the secondary droplets 116 on the steam turbine blades. As moisture may be substantially removed in upstream stationary airfoils 102 and droplet size of the remaining moisture may be reduced, the downstream rotating airfoils 104 may be less impacted by erosion.
[0025] In an alternate embodiment of the present invention, a steam/moisture separator (not illustrated) may be installed in the cavity 214 . The separator may use centrifugal force, or impingement and gravitational forces, to separate the water from the steam-water mixture. For example, but not limiting of, a cylindrical pipe may be introduced in the cavity 214 . Here, the steam-water mixture may be directed into the cylindrical pipe in the tangential direction allowing the water to separate due to the centrifugal force. The separated water may be collected and drained using the moisture draining facility 216 . The moisture draining facility 216 may then discharge the separated water to a common receiver, such as, but not limiting of, a feed water reservoir or a condenser. Alternatively, the moisture draining facility 216 may simply discard the separated water. Alternatively, any conventional mechanism may be employed to separate water from steam within the cavity 214 .
[0026] FIG. 4 is a schematic top view of an airfoil 200 having multiple inlet openings, in accordance with an alternate embodiment of the present invention. This embodiment may include a first inlet opening 402 , which may be located near the leading edge 206 on the suction-side face 212 ; and a second inlet opening 404 , which may be located along the pressure-side face 210 . The outlet opening 220 may be located near the trailing edge 208 , as illustrated in FIG. 2 . During operation, secondary droplets 116 may impact the suction side leading edge 206 . The inlet openings 402 and 404 of this alternate embodiment may be provided in this general area. This alternate embodiment seeks to maintain a minimum pressure difference between the inlet openings 402 and 404 . The position of the inlet opening 404 , along the pressure-side face 210 , may be selected to keep the pressure difference between the two inlets at a minimum level for effective operation.
[0027] The structure of the cavity 214 , including the inlet openings 402 and 404 , and the outlet openings 220 , may be similar to the structure described in connection with FIG. 2 . The steam-water mixture from both the inlet openings 402 and 404 may enter the cavity 214 . Here, the water may be separated from dry steam and exit via the outlet opening 220 , as described.
[0028] FIG. 5 is a schematic isometric view of an airfoil 200 having multiple openings, in accordance with another alternate embodiment of the present invention.
[0029] The outlet opening 220 in this embodiment may be multiple ports that blow dry steam from the cavity 214 into the main steam path 202 . In a similar embodiment, the inlet opening 218 can take the form of multiple ports. Moisture from the leading edge 206 surfaces may be directed into these ports due to the pressure drop. Recessed cavities may be provided around these inlet ports to facilitate moisture collection and to direct the moisture into the inlet ports. It will be understood that the inlet ports and outlet ports may be formed of any shape or number depending on the application and that any variation in inlet or outlet port shape, number, or size does not depart from the scope of the present invention.
[0030] FIG. 5 illustrates the moisture draining facility 216 discharging to a common receiver 500 , in accordance with an alternate embodiment of the present invention. This embodiment may be applied on a steam turbine employing multiple airfoils 200 each of which having a moisture draining facility 216 .
[0031] FIG. 5 illustrates a cavity 214 integrated with a swirling mechanism 510 , in accordance with an alternate embodiment of the present invention. The swirling mechanism 510 may assist with separating the water from the steam of the steam/water mixture flowing through the airfoil 200 . The swirling mechanism 510 may comprise the form of a swirler, impeller, or the like. Here, the steam/water mixture flowing through the airfoil 200 moves the swirling mechanism 510 .
[0032] Whenever possible, common industry terminology has been used and employed in a manner consistent with its accepted meaning in this disclosure. It is intended, however, that any such terminology be given a broad meaning and not narrowly construed such that the meaning intended herein and the scope of the appended claims is unreasonably restricted. Those of ordinary skill in the art will appreciate that often certain components may be referred to with several different names. In addition, what may be described herein as a single part may include and be referenced in another context as consisting of several component parts, or, what may be described herein as including multiple component parts may be fashioned into and, in some cases, referred to as a single part. As such, in understanding the scope of the present invention, attention should not only be paid to the terminology and description provided, but also to the structure, configuration, function, and/or usage of the component as described herein.
[0033] As one of ordinary skill in the art will appreciate, the many varying features and configurations described above in relation to the several exemplary embodiments may be further selectively applied to form the other possible embodiments of the present invention. For the sake of brevity and taking into account the abilities of one of ordinary skill in the art, all of the possible iterations is not provided or discussed in detail, though all combinations and possible embodiments embraced by the several claims below or otherwise are intended to be part of the instant application. In addition, from the above description of several exemplary embodiments of the invention, those skilled in the art will perceive improvements, changes, and modifications. Such improvements, changes, and modifications within the skill of the art are also intended to be covered by the appended claims. Further, it should be apparent that the foregoing relates only to the described embodiments of the present application and that numerous changes and modifications may be made herein without departing from the spirit and scope of the application as defined by the following claims and the equivalents thereof.
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A system for removing moisture from a steam/water mixture engaging a stationary component of a steam turbine. The system includes an airfoil located within a flow path of a steam turbine. The airfoil is configured for removing moisture from a steam/water mixture traveling in the flow path. To this end, the airfoil includes a cavity in flow communication with the steam path through at least one inlet and outlet opening, near the leading and trailing edge of the airfoil, respectively. Moisture and steam are extracted from the surface through the inlet openings, the steam and water are separated in the cavity, the separated water flows towards the bottom end, and the dry steam flows through the outlet opening and returns to the steam path. The dry steam blowing out of the trailing edge reduces the size of secondary droplets, and thereby prevents erosion.
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CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of Korean Application Nos. 2000-74762 and 2001-13235 filed on Dec. 8, 2000 and Mar. 14, 2001, respectively, in the Korean Industrial Property Office, the disclosures of which are incorporated herein by reference.
BACKGROUND
[0002] 1. Field
[0003] The present invention relates to a cathode ray tube, and more particularly, to a shrinkage band and a cathode ray tube comprising the same.
[0004] 2. Background
[0005] A cathode ray tube (CRT) is a display device in which an electron beam emitted from an electron gun excites phosphors on a phosphor screen such that the phosphors emit light, thereby creating various images. A three-ray electron beam is deflected by a deflection yoke to provide a raster scan and is separated into red (R), green (G), and blue (B) phosphors by a shadow mask, which functions as a color selection apparatus, to create precise colors.
[0006] The three-ray electron beam emitted from the electron gun illuminates designated phosphors with an accurate raster scan by way of a deflected magnetic field which corresponds precisely to apertures of the shadow mask. However, the earth's magnetic field affects the movement of electrons within the CRT. That is, the earth's magnetic field affects convergence characteristics of the electron beams (the degree to which the three-ray electron beam is focused to a single point), raster position, and purity characteristics.
[0007] The earth's magnetic field includes both horizontal and vertical components, i.e., horizontal and vertical to the earth's surface, and the intensity of the earth's magnetic field varies depending on the geographical location and positioning of the CRT. The horizontal component of the earth's magnetic field in particular affects the path of the electron beam raster and convergence. It is therefore very advantageous to block the horizontal component of the earth's magnetic field.
[0008] Heretofore, an inner shield for blocking the earth's magnetic field has been mounted in the CRT. The inner shield reduces changes in the landing of the electron beams caused by the earth's magnetic field by approximately 50 %. However, there has been little improvement in the area of effectively blocking the affect of the earth's magnetic field, and particularly the horizontal component of the earth's magnetic field on the electron beams directed toward the phosphor screen once they has passed the inner shield.
[0009] Referring to FIG. 1, a bulb defining the CRT includes a glass face panel, a funnel, and a neck, which are fused to form the bulb. Also, a shrinkage band 5 applying a predetermined tension is mounted on the bulb 3 around an outer circumference of the face panel 1 . The shrinkage band 5 acts to prevent the scattering of glass if the bulb 3 implodes as a result of external impact.
[0010] With regard to the mounting of the shrinkage band 5 , tape (not shown) is first applied to the area on the bulb 3 where the shrinkage band 5 will be positioned. Next, the shrinkage band 5 is heated to between 500 and 600° C. to expand the same. In this state, the shrinkage band 5 is placed around the bulb 3 and is then cooled, which causes the shrinkage band 5 to shrink. Accordingly, the shrinkage band 5 is mounted on the bulb 3 , applying a predetermined tension thereto.
[0011] The shrinkage band 5 is typically made of low carbon steel, which is inexpensive and has a low permeability. However, besides its use to provide support to the bulb 3 , the shrinkage band 5 has not been applied to improve the magnetic field characteristics of the CRT.
SUMMARY
[0012] In one aspect of the present invention, a shrinkage band for a cathode ray tube (CRT) includes a pair of spaced apart parallel first sides, a pair of spaced apart parallel second sides perpendicular to the first sides, the second sides being longer than the first sides, and corner portions connecting the first and second sides such that the corner portions are provided at four corners of the shrinkage band, wherein the shrinkage band is configured to go around an outer circumference of a CRT face panel skirt to apply tension to the face panel, and wherein the first sides, the second sides, and the corner portions of the shrinkage band comprise two materials each having a different permeability.
[0013] In another aspect of the present invention, a cathode ray tub includes a bulb including a face panel having a screen portion and a skirt, a neck, and a funnel between the face panel and the neck, the face panel, the funnel, and the neck being integrally formed, a phosphor screen on an inside surface of the screen portion, an electron gun configured to emit a three-ray electron beam toward the phosphor screen, a deflection element mounted to an outer circumference of the funnel and configured to generate a deflecting magnetic field to deflect the electron beam, an inner shield mounted within the bulb such that the inner shield surrounds a path of the electron beam, the inner shield being configured to reduce the influence of the earth's magnetic field, and a shrinkage band mounted around an outer circumference of the skirt to apply tension to the face panel, the shrinkage band having a pair of spaced apart parallel first sides, a pair of spaced apart parallel second sides perpendicular to the first sides, the second sides being longer than the first sides, and corner portions connecting the first and second sides such that the corner portions are provided at four corners of the shrinkage band, wherein the first sides, the second sides, and the corner portions comprise two materials each having a different permeability.
[0014] It is understood that other aspects of the present invention will become readily apparent to those skilled in the art from the following detailed description, wherein is shown and described only exemplary embodiments of the invention, simply by way of illustration. As will be realized, the invention is capable of other and different embodiments, and its several details are capable of modifications in various respects, all without departing from the invention. Accordingly, the drawings and description are to be regarded as illustrative in nature, and not as restrictive.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Aspects of the present invention are illustrated by way of example, and not by way of limitation, in the accompanying drawings in which like reference numerals refer to similar elements:
[0016] [0016]FIG. 1 is a perspective view of a prior art cathode ray tube;
[0017] [0017]FIG. 2 is a perspective view of an exemplary cathode ray tube comprising a shrinkage band;
[0018] [0018]FIG. 3 is a view taken along line I-I of FIG. 2;
[0019] [0019]FIG. 4 is a front view of an exemplary shrinkage band;
[0020] [0020]FIG. 5 is a schematic view showing the flow of horizontal components of the earth's magnetic field across the exemplary shrinkage band of FIG. 4;
[0021] [0021]FIG. 6 is a front view of an exemplary shrinkage band; and
[0022] [0022]FIG. 7 is a schematic view showing the flow of horizontal components of the earth's magnetic field across the exemplary shrinkage band of FIG. 6.
DETAILED DESCRIPTION
[0023] The detailed description set forth below in connection with the appended drawings is intended as a description of exemplary embodiments of the present invention and is not intended to represent the only embodiments in which the present invention can be practiced. The term “exemplary” used throughout this description means “serving as an example, instance, or illustration,” and should not necessarily be construed as preferred or advantageous over other embodiments. The detailed description includes specific details for the purpose of providing a thorough understanding of the present invention. However, it will be apparent to those skilled in the art that the present invention may be practiced without these specific details. In some instances, well known structures and devices are shown in block diagram form in order to avoid obscuring the concepts of the present invention.
[0024] [0024]FIG. 2 is a perspective view of an exemplary cathode ray tube comprising a shrinkage band, and FIG. 3 is a view taken along line I-I of FIG. 2.
[0025] With reference to the drawings, a face panel 2 , a funnel 4 , and a neck 6 are fused to form a vacuum bulb 8 . A phosphor screen 10 comprised of a plurality of R, G, and B pixels is formed at an inside surface of a screen portion 2 a of the face panel 2 . Also, a deflection yoke 12 is provided at a predetermined position on an outer surface of the funnel 4 , and an electron gun 14 is mounted within the neck 6 .
[0026] A shadow mask 16 , which has a plurality of apertures 16 a for the passage of electron beams, is suspended from a skirt 2 b of the face panel 2 by a mask frame 18 such that the shadow mask 16 is spaced at a predetermined distance from the phosphor screen 10 . An inner shield 20 is also mounted to the mask frame 18 such that it encompasses a path of electron beams emitted from the electron gun 14 . Further, a shrinkage band 22 is mounted to an outer circumference of the skirt 2 b of the face panel 2 .
[0027] With the above structure, if a three-ray electron beam (depicted by the dotted lines in FIG. 3) corresponding to display signals is emitted from the electron gun 14 , the electron beam is deflected by a magnetic field generated by the deflection yoke 12 toward a particular area of the phosphor screen 10 , and then is separated into R, G, and B phosphors by passing through the apertures 16 a of the shadow mask 16 to illuminate specific phosphors.
[0028] Although the inner shield 20 acts to block the earth's magnetic field, which alters the landing position of the electron beams, it is only approximately 50% effective, and once the electron beams pass the inner shield 20 , the inner shield 20 is unable to provide its blocking function.
[0029] A shrinkage band 22 is provided with magnetic field characteristics to minimize the affect of the earth's magnetic field within the CRT on the path of the electron beams in the space between the inner shield and the phosphor screen. In particular, with the shrinkage band 22 having magnetic field characteristics, the horizontal components of the earth's magnetic field that affect electron beam convergence, raster position, and purity characteristics resulting from a change in location or position of the CRT, are blocked.
[0030] One way to achieve this capability is with long sides of the shrinkage band 22 made of a material having a high permeability. With reference to FIG. 4, showing a front view of the exemplary shrinkage band 22 , the shrinkage band 22 is substantially rectangular and includes a pair of short sides 24 provided in parallel in a vertical direction (in the drawing) and at a predetermined distance from each other, a pair long sides 26 provided in parallel in a horizontal direction (in the drawing) and at a predetermined distance from each other, and corner portions 28 provided at the four corners of the shrinkage band 22 .
[0031] The long sides 26 and the corner portions 28 are made of a material having a high coercive force and high permeability, while the short sides 24 are made of a material having a low permeability. Mounted extending outwardly from the corner portions 28 by welding or some other such process are mounting tabs 30 , which are fixed to a CRT cabinet (not shown).
[0032] The high permeability material used for the long sides 26 and the corner portions 28 of the shrinkage band 22 may be a nickel-iron alloy containing 70-90% by weight of nickel; a permalloy containing 40-80% by weigth of nickel; or magnetic steel containing 0.01% or less by weight of carbon, 0.5-3.0% by weight of silicon, and the remaining percentage by weight of steel and impurities that are unavoidably present. Further, the low permeability material used for the short sides 24 may be a low carbon steel containing 0.12-0.2% by weight of carbon, for example, SPCC-1.
[0033] With the long sides 26 and corner portions 28 of the shrinkage band 22 made of a material having a high permeability as described above, components of the earth's magnetic field horizontal to the earth's surface are directed by the permeability characteristics of the long sides 26 in a direction surrounding the outer circumference of the shrinkage band 22 as shown in FIG. 5. As a result, the shrinkage band 22 prevents the horizontal components of the earth's magnetic field from entering the CRT to thereby reduce the affect of the earth's magnetic field on the path of the electron beams.
[0034] Hence, the electron beams emitted from the electron gun 14 pass within the area defined by the inner shield 20 and form the designated rasters in a state whereby they are protected from the influence of the earth's magnetic field, then pass through this area toward the phosphor screen 10 where the shrinkage band 22 acts to effectively block the affect of the earth's magnetic field, and in particular the horizontal components of the earth's magnetic field.
[0035] [0035]FIG. 6 is a front view of an alternative exemplary shrinkage band. The shrinkage band 22 is substantially rectangular and includes a pair of short sides 24 provided in parallel in a vertical direction (in the drawing) and at a predetermined distance, a pair of long sides 26 provided in parallel in a horizontal direction (in the drawing) and at a predetermined distance, and corner portions 28 provided at the four corners of the shrinkage band 22 .
[0036] The long sides 26 are made of a material of a high permeability, while the short sides 24 and the corner portions 28 are made of a material of a low permeability. The high permeability material and the low permeability material are identical to the materials described with reference to the previous exemplary shrinkage band.
[0037] As a result, with reference to FIG. 7, the horizontal components of the earth's magnetic field, rather than penetrating the shrinkage band 22 and entering the CRT, are directed by the permeability characteristics of the long sides 26 in a direction surrounding the outer circumference of the shrinkage band 22 . Therefore, the shrinkage band 22 prevents the horizontal components of the earth's magnetic field from entering the CRT to thereby reduce the affect of the earth's magnetic field on the path of the electron beams.
[0038] The shrinkage band 22 is assembled by welding or otherwise fixedly connecting various members of differing materials. The shrinkage band 22 is then heated to thermally expand the same, after which the shrinkage band 22 is placed on the bulb 8 in this expanded state, that is, the shrinkage band 22 is placed around the outer circumference of the skirt 2 b of the face panel 2 . Next, the shrinkage band 22 is cooled such that it contracts, thereby resulting in the shrinkage band 22 being fixedly positioned around the skirt 2 b of the face panel 2 to apply a predetermined tension thereto.
[0039] Although exemplary embodiments of the present invention has been described, it should not be construed to limit the scope of the appended claims. Those skilled in the art will understand that various modifications may be made to the described embodiments. Moreover, to those skilled in the various arts, the inventive aspect described herein may suggest solutions to other tasks and adaptions for other applications. It is therefore desired that the present embodiments be considered in all respects as illustrative and not restrictive, reference being made to the appended claims rather than the foregoing description to indicate the scope of the invention.
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Disclosed are a shrinkage band and a cathode ray tube (CRT) comprising the same. The shrinkage band includes includes a pair of spaced apart parallel first sides, a pair of spaced apart parallel second sides perpendicular to the first sides, the second sides being longer than the first sides, and corner portions connecting the first and second sides such that the corner portions are provided at four corners of the shrinkage band, wherein the shrinkage band is configured to go around an outer circumference of a CRT face panel skirt to apply tension to the face panel, and wherein the first sides, the second sides, and the corner portions of the shrinkage band comprise two materials each having a different permeability.
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TECHNICAL FIELD
This disclosure relates to pulse position modulation demodulators.
BACKGROUND INFORMATION
Many satellite and terrestrial optical communication systems require transmission of analog optical signals. A straightforward way to address this need is to modulate the amplitude (AM) of an optical carrier. This approach, however, suffers from a poor Signal to Noise Ratio (SNR). It is well known that broadband modulation schemes, which utilize higher bandwidth than that of the transmitted waveform, may improve the SNR over that achieved with AM. Pulse position modulation (PPM) is one of such techniques. In PPM, a shift in the pulse position represents a sample of the transmitted waveform, as shown in FIG. 1 . It can be shown that for a given power, SNR PPM ∝SNR AM (t p /τ) 2 , where t p is the spacing between un-modulated pulses and τ—the pulse duration, respectively. See H. S. Black, Modulation Theory, D. Van Nostrand (1953).
The implementations of PPM for optical communications require new techniques for generating trains of optical pulses whose positions are shifted in proportion to the amplitude of a transmitted waveform. Typically a bandwidth of Δf=1–10 GHz and higher is of interest for inter-satellite communications. Since pulse repetition frequencies (PRF) of 1/t p >2 Δf are required for sampling a signal of bandwidth Δf, GHz trains of picosecond (ps) pulses are required for realizing the advantages of PPM. For example, an optical inter-satellite link designed to transmit waveforms with Δf=10 GHz bandwidth requires sampling rates of PRF=1/t p ≧2Δf=20 GHz. By employing 1–2 ps-long optical pulses, a 30 dB gain is realized over an AM system with equal optical power.
Optical PPM offers large SNR improvements in power-starved optical links. This technology, however, requires development of new types of optical PPM receivers. One optical PPM receiver based on top hat pulse generation (THPG) has been proposed. See S. I. Ionov, “Detection of optical analog PPM streams based on coherent optical correlation”, U.S. Pat. No. 6,462,860. See also S. I. Ionov, “Optical top hat pulse generator”, US Published Patent Application No. 2003/0219195, and “PPM demodulator based on PM NOLM with improved conversion efficiency”, U.S. patent application Ser. No. 10/735,071 filed Dec. 12, 2003 which is based upon 60/488,540 filed Jul. 18, 2003.
The present disclosure describes a significantly simpler approach to PPM decoding. Because of its simplicity, the proposed device is expected to be more robust. The technology alluded to above utilizes fiber-based designs. The major drawback of the fiber-based design is in its complexity. The previous receivers were based on non-linear optical loop mirrors (NOLM) that require careful balancing and adjustments. They also need a number of EDFAs and optical filters with flat-dispersion.
The reader is also directed to U.S. patent application Ser. No. 10/701,378 filed Nov. 3, 2003 which relates to a PPM demodulator based on the gain dynamics of a semiconductor optical amplifier (SOA).
This disclosure relates to a different implementation of a PPM demodulator based on interferometric schemes involving SOAs.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 is a schematic diagram of an interferometric all-optical PPM demodulator based on UNI (Ultrafast Non-linear Interferometer) architecture;
FIG. 2 is a timing diagram of clock (i.e., control) and signal pulses in the SOA of the UNI and MZI (Mach-Zehnder Interferometer) embodiments of a demodulator;
FIG. 3 is a schematic diagram of an interferometric all-optical PPM demodulator based on MZI architecture;
FIG. 4 is a schematic diagram of an interferometric all-optical PPM demodulator based on SLALOM (Semiconductor Laser Amplifier in a Loop Mirror) architecture; and
FIG. 5 is a timing diagram of clock (i.e., control) and signal pulses in SOA of the SLALOM demodulator.
DETAILED DESCRIPTION
Schematic diagrams of interferometric PPM demodulators based on SOA are shown in FIGS. 1 , 3 and 4 . The pictured architectures are somewhat similar to ultra-fast all-optical switches based on the UNI (Ultrafast Non-linear Interferometer), the MZI (Mach-Zehnder Interferometer), and the SLALOM (Semiconductor Laser Amplifier in a Loop Mirror), respectively. See C. Schubert, J. Berger, S. Diez, H. J. Ehrke, R. Ludwig, U. Feiste, C. Schmidt, H. G. Weber, G. Topchyski, S. Randel, and K. Petermann, “Comparison of Interferometric All-Optical Switches for Demultiplexing Applications in High-Speed OTDM Systems”, J. Lightwave Tech ., vol. 20 (4), 2002, pp. 618–624. The difference between the architectures of the PPM demodulators shown in FIGS. 1 and 3 and the corresponding ultra-fast all-optical switches is that the control pulse counter-propagates with respect to one of the interfering signal pulses. Also, operating conditions have been selected for achieving linear PPM (ramp-like) response. This contrasts with typical switching applications that seek to achieve a rectangular switching window with vertical edges and also attempt to maximize the contrast between the ON and OFF states.
Preferably, the SOAs in all these demodulator embodiments operate in the gain-transparent mode. See S. Diez, R. Ludwig, and H. G. Weber, “Gain-transparent SOA switch for high-bitrate OTDM add/drop multiplexing,” IEEE Photon. Technol. Lett ., vol. 11 (1), 1999, pp. 60–62. In this mode of operation, the wavelength of control (or clock) pulses is in the spectral gain region of SOA (e.g., 1.3 mm), whereas the wavelength of the signal pulses is longer, corresponding to photon energy below the band-gap of the semiconductor material. Alternatively, both wavelengths may be in the gain region. In this case, the SOA should be current-biased to near-transparent conditions (i.e. with no significant gain or loss).
In the disclosed UNI demodulator 100 , the incoming signal pulses 102 are polarized at 45 degrees with respect to a first polarizing beam splitter (PBS) 106 , so that they are split into two orthogonally-polarized beams of equal power that pass along optical legs F and S from the output of splitter 106 towards a second PBS 116 . The optical lengths of legs F and S are preferably identical except for an intentional delay (Δτ) inserted by element 108 (which may be a thickness of glass) in the relatively slower leg S. The delay (Δτ) between the orthogonally-polarized pulses at the second PBS 116 is set close to the clock period. The polarization controllers 112 , 114 in each leg F, S ensure that both beams are combined by the second PBS 116 and launched into the SOA loop 122 in the clockwise direction in the depicted embodiment. As a result, both signal beams enter the SOA from one end thereof and move in a common direction through the SOA, while the control or timing pulse on optical path 118 enters the SOA from its opposite end. The polarization controller 124 in the SOA loop 122 assures that the faster signal component, which arrived via the faster leg F, returns to beam splitter 106 via the slower leg S and the slower signal component, which arrived in the SOA loop 122 via the slower leg S, returns via the faster leg F. Thus, the delay between the two polarization components is cancelled at the output of the interferometer.
In an alternative embodiment, the first polarizing beam splitter 106 and the unequal arms F, S before the second beam splitter 116 may be replaced by a single section of a PM fiber oriented at 45 degrees with respect to the polarization of the incoming signal pulses. See C. Schubert, S. Diez, J. Berger, R. Ludwig, U. Feiste, H. G. Weber, G. Topchyski, K. Petermann, and V. Krajinovic, “160 Gbit/s all-opticaldemultiplexing using a gain-transparent Ultrafast non-linear interferometer (gt-UNI),” IEEE Photon. Technol. Lett ., vol. 13, 2001, pp. 475–477.
The operation of the UNI PPM demodulator 100 is better understood by considering the timing diagram of signal and clock optical pulses in the SOA. See FIG. 2 . In FIG. 2 four different possible timing situations are depicted (top to bottom in the figure). In each situation the SOA is shown with two signal pulses, both traveling in the same direction through the SOA, with a clock or control signal (shown in black) propagating in an opposite direction through the SOA. The right most signal pulse or component is depicted upright and it is the signal pulse that arrives earlier since it traveled via the faster leg F. The left most signal pulse depicted for each timing situation arrives later since it traveled via the slower leg S. The control or timing pulse is depicted in black to differentiate it from the two signal pulses. In the four timing situations depicted by this figure the timing pulse goes from being relatively close to the slow leg signal pulse (S) to being relatively close to the fast leg signal pulse (F) to being very close to the slow leg signal pulse (S) when viewing the four situations from top to bottom in FIG. 2 . Of course, those skilled in the art will appreciate that these four timing situations are merely exemplary of the possible timing situations that will occur in these optical circuits.
In FIG. 2 , the delayed signals are depicted in a bent fashion which represents the fact that the slow component of the signal is orthogonal to that of the fast one in a UNI PPM demodulator.
The timing of clock versus signal pulses in the SOA is set in such a way that minimum and maximum delays between the slow signal pulse or component and the corresponding clock or control pulse (at the moment when the clock or control pulse enters the SOA 126 ) represent, respectively, the minimal and maximal values of the transmitted waveform. In this arrangement, the fast component or pulse (F) of the signal always exits the SOA 126 before the corresponding clock pulse enters into it. The crosshatched region in the SOA has a length that is equal to one half the distance between the slow leg component or pulse and the control pulse at the moment when the control pulse enters the SOA. The total length of the SOA 126 is preferably chosen to be sufficiently long that at a maximum delay between the signal and clock pulses, the latter collides with the slow component or pulse of the signal before exiting the SOA 126 . For example, for a 10 G/s pulse rate, L≧Tc/2n=4.5 mm, where T=100 ps is the pulse period and n=3.3 is the index of refraction.
The clock pulse changes the carrier density in the SOA (in the crosshatched region), which affects the phase shift of the slow signal component with respect to the fast one (the cross hatched lines in the SOA depict the length along the SOA that the control or clock pulse has traveled when it encounters (collides with) the slow signal component or pulse and thus depicts where the carrier density of the SOA has been changed by the clock or control pulse when the collision occurs). The length of the crosshatched region is proportional to the relative phase shift. As a result, when the two polarized signal components recombine at the output 107 of beam splitter 106 , they do so into a different polarization state (which is determined by their relative phase shift), and a portion of the signal pulse will pass through the output polarizer 130 . As seen from FIG. 2 , the length of the SOA, which is affected by the clock pulse and sampled by the slow signal component or pulse (S), is proportional to the delay between the signal and the clock. Therefore, the corresponding phase shift between the two polarized components of the signal is also proportional to the delay, assuming that the clock pulse is not attenuated significantly in the SOA. If the latter condition is not satisfied, the SOA should be current-biased for near-transparency at the clock wavelength as previously mentioned.
The optical field amplitude after the polarizer is E=E o (cos(ωt+φ)cos(α)+cos(ωt)sin(α)), where φ is the relative phase shift acquired by the slow signal component in the SOA 126 and α is the tilt of the output polarizer 130 with respect to the principal polarization direction of the signal. The polarization controller 128 and the polarizer 130 at the output of the interferometer are adjusted to have zero signal transmission at minimal delay between the signal and the clock pulses. In this case, α=−π/4 and E/E o ∝sin(φ/2)≈φ/2. The electric amplitude of the signal is converted to electrical current in a homodyne detector 132 , which beats the output signal against a phase-locked local oscillator 136 on a photodiode 134 . The local oscillator 136 is preferably implemented by a DFB laser diode. Since the output current of the homodyne receiver 132 is proportional to the amplitude of the output signal (in the linear regime), it is also proportional to the phase shift φ, which is, in turn, proportional to the delay between the signal and clock optical pulses. Therefore, the electrical output of the UNI demodulator 100 depicted in FIG. 1 is proportional to the delay between the signal and clock pulses. In an MZI PPM demodulator 300 as shown in FIG. 3 , the signal is preferably split by a 3 dB coupler 301 into two components that travel in two separate legs 304 , 306 (each leg has the same optical length in this embodiment, but for the existence of the intentional optical delay 312 , 314 ) before they are recombined by a second 3 dB coupler 324 . A clock pulse 303 induces two non-linear index changes in the two legs 304 , 306 of the interferometer that depend on the relative delays between the counter-propagating control and signal pulses in each leg. The control pulse in one leg 304 of the interferometer is delayed (by optical delay 305 ) by about one clock period with respect to that in the other leg 306 , and the length of each SOA 308 , 310 is traveled by optical pulses in one half of the clock period. The clock (i.e., control) pulse is aligned similarly to the alignment in the UNI demodulator. In one leg, the control pulse collides with the corresponding signal pulse at the entrance of the SOA if maximum PPM delay is present. In this configuration, the phase shift experienced by the signal pulse in the first leg 304 is proportional to the delay between the signal and the clock. This operation is similar to that in the UNI demodulator (see again the timing diagram of FIG. 2 ) although now two signal pulses in the two legs have the same polarization. Also, the signal pulses may be aligned in time whereas control pulses are split. However, the relative pulse positions of control and signal pulses are similar to that of the previously described UNI PPM demodulator embodiment. The control or timing pulse in the other leg 306 always enters the SOA after the corresponding signal pulse has already exited, thereby imprinting no phase shift on the signal pulse. Therefore, the differential phase shift between the two signal components is proportional to the PPM delay between the signal and control pulses.
Alternatively, the signal pulses in one leg 304 or 306 could be delayed instead of delaying the corresponding control pulses as described above.
The MZI demodulator is balanced in the absence of clock pulses either for a 50/50 split at the output, or for zero output from the detector leg (see FIG. 3 ). In the first case (the 50/50 split), a simple photodiode 326 provides linear conversion of the PPM phase shift into the output current. In the second case (the zero output), a homodyne detector is utilized for linear conversion, similar to the UNI embodiment of FIG. 1 . For illustrative purposes, only the first case (the 50/50 split embodiment with the simple photodiode) is shown in FIG. 3 since an exemplary homodyne detector is already shown in connection with the embodiment of FIG. 1 .
To balance the interferometer, an optical delay (OD) 312 , 314 , an attenuator (ATN) 316 , 318 and a polarization controller (PC) 320 , 322 are preferably used in each leg 304 , 306 . The optical delays 312 , 314 are optional—they may be needed if bulk optics and fibers are used and/or if there exists a temperature imbalance between the two legs to assure correct timewise pulse alignment. In addition, active phase stabilization must be implemented for proper operation so it may be necessary to also include a phase shifter in at least one of the legs 304 , 306 . One of the advantages of the SLALOM and UNI embodiments is that timewise pulse alignment is achieved inherently by the configurations of the light paths employed so that optical delay devices in each leg, comparable to ODs 312 , 314 , and/or phase shifters are ordinarily not needed in those embodiments.
FIG. 4 depicts the SLALOM demodulator embodiment 400 . In this embodiment incoming signal pulses 402 are split by an adjustable 3 dB input-output coupler 405 into two components, one propagating in the clockwise direction in the loop 404 depicted in the figure (so that the signal initially enters leg 404 ) and the other in the counterclockwise direction in FIG. 4 (so that the counterclockwise signal initially enters leg 406 ). In this embodiment the SOA 426 is placed timewise asymmetrically in loop 402 due to the presence of an optical delay element 408 in leg 406 , so that the counter-propagating pulses reach the SOA 426 with an intentional delay equal to the clock period (Δτ). Otherwise, without the intentional delay, both legs have the same amount of delay associated therewith. Without a control pulse, the loop is balanced for 100% reflection by a PC 420 and the adjustable 3 dB coupler 406 . The length of the SOA is chosen so as to be crossed by the counter-propagating optical pulses in one half of the clock period (0.5·Δτ).
A timing diagram explaining the operation of the SLALOM demodulator is shown in FIG. 5 . The clock pulse always arrives at the SOA 426 prior to the corresponding co-propagating signal pulse. As a result, the co-propagating signal pulse in the clockwise (CW) direction in the depicted loop always acquires maximum phase shift. (This is opposite to the operation of the UNI or MZI demodulator embodiments shown in FIG. 2 , where the fast component never acquires a phase shift in the disclosed embodiments.) On the other hand, the counter-propagating signal pulse—in the counterclockwise (CCW) direction in the depicted loop—acquires a phase shift that is proportional to the PPM delay between the signal and clock pulses (similar to the operation of the disclosed UNI and MZI demodulators). Therefore, the differential phase shift acquired by the two signal components is proportional to φ∝1−t PPM , i.e. proportional to the negative of the transmitted waveform.
The output optical field of the SLALOM demodulator 400 is proportional to sin(φ)≈φ. The electric amplitude of the signal is converted to electrical current in a homodyne detector 428 , which beats the output signal against a phase-locked local oscillator 432 on a photodiode 430 . Since the output current of the homodyne receiver is proportional to the amplitude of the output signal (in the linear regime), it is also proportional to the phase shift φ, which is, in turn, proportional to the negative of the delay between the signal and clock optical pulses. Therefore, the electrical output of the SLALOM PPM demodulator 400 is proportional to the negative of the delay between the signal and clock pulses. The optical paths in the previously described embodiments are assumed to be in free space. However, after accounting for path lengths, the paths could be in other media such as optical fibers. If optical fibers are utilized and the delays in the optical fibers are appropriately adjusted, then the optical delay devices, such as element 108 in the embodiment of FIG. 1 , may be omitted.
Having described this technology in connection with certain embodiments thereof, modification will now doubtlessly suggest itself to those skilled in the art. As such, the present invention is not to be limited to the disclosed embodiments except as specifically required by the appended claims.
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An optical demodulator for use as a pulse position demodulator. The demodulator has one or more semiconductor optical amplifiers coupled to receive an optical signal to be demodulated at first end thereof and for receiving optical control pulses at a second end therefore, the optical signal to be demodulated and the optical control pulses counter-propagating in said one or more semiconductor optical amplifiers in order to determine a delay or phase shift there between; and a detector coupled to the one or more semiconductor optical amplifiers for recovering, as an electrical output signal, the delay or phase shift in the optical signal.
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BACKGROUND AND SUMMARY OF THE INVENTION
Many very different ways of preparing labels are known. It can be done by engraving the desired symbols on a carrier material of appropriate shape or by providing a piece of roughened plastic foil with the symbols--for example, by putting the symbols on with a typewriter and then cementing the piece of foil bearing the symbols onto a carrier foil. It can also be done by cementing the symbols on a transparent plastic foil, with a varnish which is or becomes transparent at the latest after hardening and which has an index of refraction sufficiently similar to that of the plastic foil. The varnish may be sprayed or painted on the foil. Suitable varnishes with the required qualities are known, but plastic varnishes are recommended, especially those which are irreversible when hardened. For instance, a two-component varnish may be used, such as the well-known "DD" varnishes which, when hardener is added, cross-link to form a plastic coating.
The method of preparing a rather large number of labels by imprinting the symbols on individual backings cut to size by the silk-screen process is also known. However, that is a method which is only useful when a large number of labels, all bearing the same symbols or the same lettering, is required.
Another method for preparing a number of labels consists of putting all of the desired symbols or lettering on one base--with a typewriter, with letters which are applied by rubbing, or the like--and then cutting up the base to make the individual labels. It is relatively easy to perform such a cutting process if the base is a sheet of paper or a thin plastic foil. However, the cutting becomes difficult if the base is relatively stiff, or, if after the symbols have been put on, the base is reinforced by cementing on a relatively stiff plastic foil covering the symbols or by cementing a backing foil onto the back of the base. For practical purposes, a base reinforced in that way cannot be cut up in the usual manner so that all labels are of the same size and the lettering is located centrally on all labels and the edges of the individual labels are exactly straight and run exactly parallel and/or perpendicular to each other.
All of these methods of preparation have a disadvantage when they are used in the preparation of individual labels for the many uses to which they can be put, e.g., for switchboards and other installations, where a large number of labels of the same size, but with different lettering, is required.
Therefore, it is the object of the invention to provide a method which makes it possible to prepare a large number of individual labels whose symbols or letters are first put on a base which is common to all labels and which thereafter is cut in such a way that the edges of the individual labels are exactly parallel and/or perpendicular to each other, with the lettering being located centrally on the individual labels if that is desired.
A method for preparing a large number of labels has been devised in which the symbols for the labels are put on a base arranged in marked rows and columns, a transparent plastic foil is then cemented onto the face of the base and/or a backing foil or material is cemented onto the back of the base. The base which has been reinforced in that way is then cut up in one of two methods. One method is to first cut the base so that two adjoining edges of the base, which is bound with the plastic foil and/or the carrier foil or material, are cut at right angles to each other, so that one edge runs parallel to the rows on which the symbols have been placed and the other edge runs perpendicular to those rows. The base is then laid with one of its edges against a bearing surface and cut along the markings which are parallel to the cutting edge (perpendicular to the edge bearing on the bearing surface). The resulting strips made in this way are reassembled in the same sequence and aligned by means of a carrier foil or material. The reassembled base is then laid with its second adjoining edge on a bearing surface and cut along the markings (perpendicular to said second adjoining edge). A second method is to cut the base row by row according to the markings, align the strips made in this way centrally with respect to a column, connect the strips by means of a carrier material in the area of that column and then cut along the edges of the column. The remaining strips portions are then aligned centrally with respect to their respective columns, connected by means of a carrier material and cut.
Thus, in accordance with the methods of the invention, a base is made with markings and symbols which is reinforced by the plastic foil and/or the backing foil or material in such a way that the inaccuracies which arise when cutting in one direction--say, cutting row by row--are not added in with or onto the inaccuracies which arise when subsequently cutting perpendicular to the first cutting operation. Specifically in the case of the first-mentioned method, when the strips resulting from the first cutting operation are in the same sequence and alignment by means of the carrier material and are joined together again, what results is the original form of the base, and consequently the individual labels and the symbols and letterings of the individual labels lie in the same positions with respect to each other again. Thus a second cutting can take place without the first cutting having any influence on the shape, accuracy and direction of the second cutting, and consequently having any influence on the label edges resulting from the second cut.
In the second method, a row by row cutting takes place first, and then the individual columns are aligned centrally. This can be accomplished by laying them on a grating for example. Then all strips of a column aligned in that way are bound by means of the carrier foil or material, so that a cutting in the direction in which the columns extend can again take place without the course of such a cut being influenced by the course of the cuts which were previously made in the direction in which the rows extend. Preferably, the carrier foil or material used for reassembling the strips can itself be pliable--for example, the carrier foil or material can consist of a transparent plastic foil. If that is so, the cementing is naturally carried out in such a way that the carrier foil or material can also easily be pulled off again. Consequently, the labels of one column adhere to the carrier material after the cutting has taken place so that the user can select the desired label very easily and detach it from the carrier material in order to place it in the desired location.
BRIEF DESCRIPTION OF THE DRAWINGS
In the following, the invention is described in more detail with the help of the drawings, in which:
FIG. 1 shows an embodiment with a base for preparing labels which is partially covered with lettering.
FIG. 2 shows another embodiment of a base for preparing labels.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The base shown in FIG. 1 is made of a transparent material such as a thin plastic foil with a roughened surface, which can have lettering or symbols put on it with a typewriter, or in some similar way. The base is divided into three columns--1, 2 and 3--and the middle column is separated from the outer ones by the lines 4 and 5. There are markings in the individual columns, although only the markings in Column 1 are labeled, with the markings 12 and 15 indicating the middle of the column and the markings 13 and 16 and 14 and 17 indicating the edges along the sides of the labels which are to be prepared. Markings for the lines separating the horizontal rows--8, 9, 10 and 11, for example--are provided, and the individual rows are numbered from 1 through 20, inclusively, along the left-hand edge.
To prepare a large number of labels, the lettering is put on the base in the manner indicated in FIG. 1, so that the lettering is located in the middle of the columns and rows. After the lettering is completed, the base may be cemented to a white backing foil so as to obtain a white background, and a transparent plastic foil may be cemented on top of the base to form a composite sheet, preferably with a transparent adhesive which has the same refraction index as the material of the base such the well known two component "DD" varnishes which, when hardener is added, cross link to form a plastic coating.
It should be pointed out that a white backing foil which has an adhesive covered with protective foil on its back can be used so that self-cementing labels can be prepared. After the backing foil and the transparent plastic foil have been put on, the unit formed in this way may be put through a hand-operated roll press in order to produce a firm union of all the individual layers.
Since it generally is not possible to fasten the transparent plastic foil and/or the backing foil or material to the base in such a way that a precise alignment of the adjoining side edges with each other results, the base has two lines 6 and 7 running perpendicular to each other, the line 6 of which runs parallel to the lines 4 and 5, that is, parallel to the direction of the columns. These lines 6 and 7 are used to obtain edges running perpendicular to each other. The base, with the transparent plastic foil and/or the carrier foil or material may be cut with a simple lever shears, first along the line 6 and then along the line 7, so that one gets one bearing edge which runs parallel to the direction of the columns and one bearing edge which runs parallel to the direction of the rows. Now the base sheet with attached foil or foils is laid along one bearing edge against a bearing surface and cut perpendicular to said one bearing edge into strips making use of the line markings.
The individual strips are then put back together again in the same sequence and alignment such that all strips are in exact alignment with each other as they were previously aligned.
The next step is to cement a carrier foil or material made of transparent material onto the strips which have been put together again. The lettering and markings are discernible through that foil.
The strips which have been put back together again by means of the carrier material are then laid with the second bearing edge corresponding to the line 6 or the edge corresponding to the line 7 against a bearing surface and then, if the first cutting was along the rows, cut perpendicular to the second bearing edge along the markings 13, 16 and 14, 17 and the corresponding markings of the columns 2 and 3. Labels of the desired size then result from this cutting, and all markings provided on the base have been removed during the cutting since they do not extend into the area of the labels.
It is at once clear that this method of the invention thus makes it possible, in an easy way and making use of equipment which is customarily to be found in offices, to prepare a large number of accurate labels of at least the same width quickly--labels which have the same or different lettering.
Where labels with a colored background are to be prepared in a corresponding manner, it is necessary to use a base of appropriate color which is not transparent. Such a base can be used in the same way as the base shown in FIG. 1.
Where one wants to make use of a grating to help in lettering the base, since using such a grating simplifies putting the label lettering on the base centrally, a base such as is shown in FIG. 2 can be used.
The base shown in FIG. 2, like that shown in FIG. 1, has three columns 1', 2' and 3', and the column 2' is bordered by two parallel lines 4' and 5', which at the same time form the boundary of the adjoining column. As is indicated in column 1', the middle of the columns is indicated by markings 12' and 15'. Markings for rows are also located at the dividing lines 20. Those dividing lines are made by double strokes whose width and distance apart correspond to the width of a letter, so that they can be used to achieve a placement of the letters centrally with respect to the middle of the columns. For additional assistance in distributing the characters to be used on a label, horizontal middle-line markings (18 on line 4') and supplementary markings (19 on line 4') are provided which are used when a label is to have two lines of text.
The base, bound with a plastic foil and/or a backing foil or material to form a composite sheet which has been described, is first cut row by row along the upper and lower label-bordering markings, which are only shown for one line--namely, the upper label-bordering markings 8", 9", 10" and 11" and the lower label-bordering markings 8', 9', 10' and 11'. After the prepared base has been cut into individual strips, these are then aligned with respect to the middle of a column. For this purpose, a grating with a middle line, for example, is used and the strips are laid on it so that the middle of the labels contained within the column coincides with the middle line of the grating, or else the column boundary lines 4' and 5' of the strips are brought into alignment. In any case, at least the lower edges of all aligned strips run parallel to each other. This parallel arrangement can be achieved either by laying the strips on a cross hatched base or aligning the strips in relation to appropriate pins which are arranged in pairs on parallel lines, with the distance between adjacent lines being greater than the height of the cut strips.
The strips, which are then joined to each other in a realignment as before in the area of a column by means of the carrier film or material, are then cut, using the markings 13', 16' and 14', 17' or the markings of the column concerned, so that a column of exactly dimensioned, accurate, finished labels results.
The strip sections not held by the carrier material during this cutting are processed into finished labels in the same manner by aligning them by columns, joining them by means of carrier material and cutting them. Alternatively, the respective areas of each column may be joined by carrier material and the second cutting may be performed consecutively on each column.
Although only two exemplary embodiments of the methods of this invention have been described in detail above, those skilled in the art will readily appreciate that many modifications are possible in the exemplary embodiments without materially departing from the novel teachings and advantages of this invention. Accordingly, all such modifications are intended to be included within the scope of this invention as defined in the following claims.
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A method for forming a large number of labels from a base sheet on which markings and symbols are imprinted on rows and columns. This base is reinforced with a transparent sheet cemented to the front of the base and/or a backing foil or material cemented to the rear face of the base. Perpendicular edges are cut, parallel to the rows and perpendicular to the columns respectively. Cuts are then made making individual strips. The strips are realigned, connected together and cuts are made, separating the reconnected base into a series of labels.
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The present application is a continuation of U.S. patent application Ser. No. 09/426,655, filed Oct. 25, 1999, now U.S. Pat. No. 6,262,155, which is a continuation of U.S. patent application Ser. No. 08/817,561, filed Apr. 21, 1997, now U.S. Pat. No. 5,973,039, which is a 371 of PCT/US95/14652, filed Nov. 9, 1995, which claims the benefit of U.S. Provisional patent application Ser. No. 60/000,829, filed Jul. 28, 1995, and of French Patent Application No. 94 14933, filed Dec. 12, 1994.
FIELD OF THE INVENTION
The invention relates to new photochromic transparent organic materials with a high refractive index, to a process for their preparation, and to the articles made of these materials.
BACKGROUND OF THE INVENTION
It is difficult to find a photochromic material allowing for the production of an ophthalmic lens whose transmittance varies as a function of the lighting. Outside of their photochromic properties (i.e., colorability, rapid darkening and lightening kinetics, acceptable durability, etc.), such lenses are generally made by the use of appropriate mixtures of photochromic compounds such as spirooxazines and chromenes. The polymer matrixes which are used, though thermally crosslinked, have a low glass transition point, generally lower than that of CR39®, a reference ophthalmic resin consisting of diethylene glycol bis(allyl carbonate) available from PPG Industries, so as to have rapid photochromic kinetics. Moreover, these polymers generally have a relatively low refractive index (<1.54).
The majority of these thermally crosslinked matrixes are obtained by radical polymerization (i.e., polymerization which most often can only be carried out provided that one uses initiators of the organic peroxide type.) The use of organic peroxides makes it practically impossible to incorporate photochromic molecules in the mixture of monomers before polymerization, the peroxides having the effect either of destroying any photochromic effect or of giving the product an unacceptable permanent intense coloration. Also, one is obliged to later incorporate coloring agents into the matrix, most often by a special thermal diffusion process.
Therefore, there continues to be a need for photochromic trans-parent organic materials which have improved photochromic properties and which are easy to manufacture and not very expensive to manufacture.
SUMMARY OF THE INVENTION
Briefly, the invention relates to new photo-chromic transparent organic materials which are particularly useful for the production of photochromic organic ophthalmic lenses. The organic material consists of an optical-quality polymer matrix and at least one coloring agent giving photochromic properties to the matrix. The coloring agent is chosen from the group of the spirooxazines, the spiropyrans, and the chromenes. The polymer of the matrix is chosen from (a) homopolymers of ethyoxylated bisphenol A dimethacrylate having formula I:
in which R is H or CH 3 , and m and n independently represent 1 or 2, and (b) copolymers of ethoxylated bisphenol A dimethacrylate containing, at most, 30 wt % of at least one aromatic monomer with vinyl, acrylic, or methacrylic functionality.
Surprisingly, we have found that the materials of the invention are characterized particularly by a glass transition point, and therefore by a hardness, which is greater than that of many hitherto known organic ophthalmic products without any adverse effects on the darkening and lightening speeds. We have also found that, through the choice of an appropriate mixture of several coloring agents, it is possible to obtain the desired tint in such matrixes, particularly gray or brown, with this tint practically not varying in the course of darkening and lightening.
The inventive organic materials also exhibit a high refractive index, which is in all cases greater than 1.54, and which can be adjusted, if necessary, to the desired value by the use of an appropriate modifying comonomer.
Useful co-monomers for the invention include vinyl, acrylic or methacrylic compounds containing in their formula one or more benzene nuclei. Examples of some useful co-monomers are, divinylbenzene, diallyl phthalate, benzyl or naphthyl acrylates or methacrylates, etc., as well as their derivatives substituted on the aromatic nucleus or nuclei by chlorine or bromine atoms.
In another aspect, the invention also relates to a process for the preparation of the photochromic organic materials of the invention by polymerizing an ethoxylated bisphenol A dimethacrylate, corresponding to formula I:
in which R is H or CH 3 , and m and n independently represent 1 or 2, optionally with up to 30 wt % of one or more modifying aromatic monomers with vinyl, acrylic or methacrylic functionality, in the presence of a diazo radical initiator and in the absence of a peroxide radical initiator. Preferably, R is H, and m=n=2.
Preferably, the polymerization is carried out in the presence of at least one photochromic coloring agent, which allows one to color the final material in its mass.
DETAILED DESCRIPTION OF THE INVENTION
An essential characteristic of the present process is that it is implemented in the absence of a peroxide radical initiator, the latter being replaced by a diazo initiator. This has the advantage of allowing one to incorporate the photochromic coloring agent in the resin matrix before polymerization of the matrix. Polymerization in the presence of the coloring agent cannot be carried out with a peroxide initiator because the latter may generate a strong initial coloration of the resulting organic glass. The peroxide initiator may also lead to a loss of the photochromic effect. Accordingly, in current processes for the production of organic glasses, when a peroxide initiator is used, a separate coloration step is required in order to re-impart photochromic properties or color back into the glass. As stated earlier, the coloration is generally done for example, by the diffusion of the coloring agent or agents into the glass matrix, usually at elevated temperatures. The preferred inventive process avoids this additional coloring step, and if desired, allows for the production of a photochromic lens in a single step by carrying out the polymerization directly in a lens mold.
Of course, if desired, the coloring agent can be omitted from the polymerizable mixture, and the incorporation of the photochromic coloring agent or agents in the polymerized matrix can be carried out by a conventional thermal diffusion process as described for example, in U.S. Pat. Nos. 5,130,353, 5,185,390 and 5,180,254. According to the method described in these references, a substrate impregnated with photochromic coloring agent or agents is applied to one surface (usually the convex surface in the case of a lens) of the polymer matrix. The impregnated substrate is then heated to 100-150° C. for one to three hours, and finally the substrate is separated from the polymer matrix.
The photochromic coloring agent can be chosen from the general classes of the spirooxazines, spiropyrans and chromenes having photochromic properties. Quite a large number of photochromic coloring agents are described in the literature and are commercially available and are described for example in U.S. Pat. Nos. 5,246,630 and 4,994,208, both herein incorporated by reference.
Examples of useful spirooxazines for the invention are described in U.S. Pat. Nos. 3,562,172; 4,634,767; 4,637,698; 4,720,547; 4,756,973; 4,785,097; 4,792,224; 4,784,474; 4,851,471; 4,816,584; 4,831,142; 4,909,963; 4,931,219; 4,936,995; 4,986,934; 5,114,621; 5,139,707; 5,233,038; 4,215,010; 4,342,668; 4,699,473; 4,851,530; 4,913,544; 5,171,636; 5,180,524; and 5,166,345, and also in EP-A 0,508,219; 0,232,295; and 0,171,909, among others, herein incorporated by reference.
Examples of chromenes that can be used are described also in U.S. Pat. Nos. 3,567,605; 4,889,413; 4,931,221; 5,200,116; 5,066,818; 5,244,602; 5,238,981; 5,106,998; 4,980,089; and 5,130,058 and EP-A 0,562,915, all herein incorporated by reference.
Useful spiropyrans have been described in the literature, for example, in Photochromism, G. Brown, Ed., Techniques of Chemistry, Wiley Interscience, Vol. III, 1971, Chapter III, pp. 45-294, R. C. Bertelson; and Photochromism. Molecules & Systems, Edited by H. Dürr, H. Bouas-Laurent, Elsevier, 1990, Chapter 8, “Spiropyrans,” pp. 314-455, R. Guglielmetti, all herein incorporated by reference.
On an indicative and nonlimiting basis, the proportion of photochromic coloring agent(s) to be incorporated in the matrix can range from 0.03 to 0.3 wt %, and preferably from 0.05 to 0.1 wt %.
Preferably also, one uses a combination of photochromic coloring agents giving a gray or brown tint in the darkened state.
As diazo radical initiator, it is possible to use azobisisobutyronitrile (AIBN) and 2,2′-azobis(2-methylbutyronitrile), among others. Other examples of useful diazo radical initiators are also described in “Polymer Handbook,” by Bandrup and Immergut, p. II-2, John Wiley (1989).
To carry out the polymerization, it is possible, for example, to heat the polymerizable mixture slowly until the beginning of thermal degradation of the diazo compound with release of nitrogen and free radicals. This can occur at a relatively low temperature which depends on the diazo compound which is used (approximately 65° C. in the case of AIBN). The polymerization is carried out for several hours, for example, 10-20 hours. One finally proceeds to anneal the structure by heating in successive temperature stages, which can exceed 100° C., and for a duration of approximately 1 hour each.
The invention finally relates to the articles consisting completely or partially of a photochromic organic material according to the invention.
Nonlimiting examples of such articles are lenses for ophthalmic (corrective) glasses or sunglasses, windows for automobiles and other vehicles, windows for buildings, etc. In the articles of the invention, the photochromic organic material of the invention can constitute the whole thickness of the article (solid article) or can be in the form of a film or layer stratified on a transparent organic or mineral support.
Lenses, especially ophthalmic lenses, are particularly preferred articles of the invention.
These lenses can be produced conveniently by carrying out the polymerization in lens molds, in a conventional manner, for example, as described in U.S. Pat. Nos. 2,242,386; 3,136,000; and 3,881,683 which are herein incorporated by reference.
The stratified articles can be produced easily by application of the polymerizable mixture (for example, by immersion, by centrifugation, by brush, etc.) to the support and polymerization of said mixture in situ.
EXAMPLES
In order to suitably understand the invention, the following nonlimiting examples are given. The parts are parts by weight.
Example 1
(Reference)
Two non-photochromic organic glasses are prepared by the following mode of operation:
A) 100 parts of Diacryl 121 (tetraethoxylated bisphenol A dimethylmethacrylate (formula I in which R 1 =CH 3 , R 2 =H, and m=n=2) sold by the AKZO Company) is mixed with 0.25 part azobisisobutyronitrile (AIBN) as initiator. The mixture is polymerized in a lens mold for 16 hours at 65° C. in a nitrogen atmosphere. The resulting mold is posthardened for 1 hour at 70° C., for 1 hour at 80° C. and for 1 hour at 110° C. so as to obtain an organic lens after removal from the mold.
B) In this second stage, operation A is repeated except that the Diacryl 121 is replaced by Diacryl 101 (diethoxylated bisphenol A dimethylmethacrylate (formula I in which R 1 =CH 3 , R 2 =H, and m=n=1) sold by the AKZO company).
The physical properties of these glasses, as well as those of a reference organic glass commercially available under the registered brand CR39® and consisting of the homopolymer of diethylene glycol bis(allyl carbonate), are indicated in Table I hereafter.
TABLE I
Compared physical properties
Glass Derived
Glass Derived
CR39 ®
From Diacryl 101
From Diacryl 121
Shore D Hardness
84
89
84
Vickers Hardness
215
490
230
(N/mm 2 )
Elastic Modulus
3.34
5.30
3.40
in GPa
3.17
5.10
3.34
by DMA
by Vickers
Glass Transition
94° C.
156° C.
107° C.
T g (max t gδ )
Refractive Index
1.498
1.565
1.5575
n D 20
One observes that the polymer materials used in the invention at the same time have mechanical properties that are equivalent to or superior to those of CR39®, the reference product, and a clearly higher refractive index values.
Example 2
Same process as Examples 1A or 1B, except that a photochromic coloring agent chosen from the table below is incorporated into the polymerization mixture. The coloring agent is dissolved in the monomer with stirring and slight heating.
Coloring Agents
COLORING AGENT NO.
FORMULA
NOMENCLATURE
1
1,3,3-Trimethylspiro [2H-indole-2,3′-[3H] phenanthra(9,10b)[1,4] oxazine]
2
5-Chloro derivative of coloring agent No. 1
3
1,3,3-Trimethylspiro [indolino-2,3′[3H]-naphtho (2,1b)(1,4)oxazine]
4
1,3,3,5,6-Pentamethylspiro [indolino-2,3′[3H]-naphtho (2,1b)(1,4)oxazine]
5
1,3,3-Trimethylspiro [indolino-6′-(1-piperidyl)- 2,3′[3H]-napththo (2,1b)(1,4)oxazine]
6
3,3-Diphenyl-3H-naththo [2,1b]pyrane
In the photochromic materials or glasses obtained, the times of half-darkening and half-lightening are measured. The light source is a mercury vapor lamp, and the measurement of transmission is done at the wavelength of λ max of the coloring agent and at room temperature on a 2-mm-thick sample. Table II below recapitulates the results obtained for various photochromic materials according to the invention.
TABLE II
t 1/2
t 1/2
Dark-
Light-
Photo-
Color-
ening
ning
chromic
ing
λ max
Concen-
(sec-
(sec-
Glass
Matrix
Tg
Agent
(nm)
tration
onds)
onds)
1
Diacryl
156° C.
3
605
0.3%
3
4
101
2
Diacryl
—
6
435
0.4%
4
7
101
3
Diacryl
—
1
605
0.05%
5
7
101
4
Diacryl
—
2
590
0.05%
7
11
101
5
Diacryl
109° C.
3
605
0.3%
3
4
122
6
Diacryl
—
4
605
0.2%
3
6
121
The examples above show that, regardless of the type of photochromic compound used, one observes with all the glasses of the invention rapid kinetics of darkening as well as lightening, in spite of the high T g values of the resins, particularly in the case of Diacryl 101 (T g =156° C.), with the best mode being represented by photochromic glass 1.
Example 3
A photochromic lens with a gray tint is prepared according to the mode of operation of Example 1A, except that one incorporates in the polymerization mixture 0.2 part No. 4 blue coloring agent, 0.025 part No. 5 red coloring agent and 0.20 part No. 6 yellow coloring agent.
The lens obtained has rapid darkening and lightening properties. The kinetics of the three coloring agents used being similar, the lens keeps its neutral gray tint during the process of darkening, as well as that of lightening. The lens has a good photostability with time as shown by the results presented in Table III below, of transmittance measurements before and after 283 hours of exposure at a wavelength of 560 nm (60,000-lux xenon lamp) at 20° C.
TABLE III
Transmittance
Before
After
To 910
84.9%
82.5%
T D15 (2)
26.5%
28.1%
T F5 (3)
72.7%
71.6%
T o corresponds to the initial transmission of the lens.
T D15 =% transmission at 560 nm after 15 min of exposure under the xenon lamp; thickness of sample: 2 mm.
T F5 =% transmission at 560 nm after 15 min of exposure and 5 min of lightening in darkness.
Example 4
This example illustrates the variant of the process of the invention consisting of incorporating the photochromic coloring agent by diffusion after polymerization.
One prepares a lens according to the mode of operation of Example 1, and therefore not containing any photochromic coloring agents.
One prepares a solution of 1 g of coloring agent No. 4 in 10 g of tetrahydrofuran. One impregnates a disk of filter paper with the solution thus prepared; one applies the filter to the convex front surface of the lens obtained. One maintains the lens under pressure by means of a mineral glass lens with the same radius of curvature as the plastic lens, and one heats it for 2 hours at 130° C. One separates the components, and stoves the lens obtained for 2 hours at 110° C.
The final lens obtained is photochromic with the following characteristics (measured at λ max =616 nm).
Initial transmission T o =86.6%
Transmission in the darkened state=13.8%
Half-darkening time t ½ =3 sec
Half-lightening time t ½ =4 sec
The results obtained (kinetics) are completely comparable to those obtained by incorporation in the matrix beforehand (see Example 2).
It goes without saying that the embodiments described are only examples, and one could modify them, particularly by substitution of equivalent techniques, without consequently leaving the scope of the invention.
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The invention relates to photochromic transparent organic materials particularly useful for the production of photochromic organic ophthalmic lenses. The material includes an optical-quality polymer matrix and at least one coloring agent giving photochromic properties to the matrix. The coloring agent is chosen from the group of the spirooxazins the spiropyrans, and the chromenes. The polymer of the matrix is chosen from the group of homopolymers of ethyoxylated bisphenol A dimethacrylate with formula I:
in which R is H or CH 3 , and m and n independently represent 1 or 2, and of the copolymers of this dimethacrylate containing at most 30 wt % of an aromatic monomer with vinyl, acrylic or methacrylic functionality.
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CROSS-REFERENCE TO RELATED APPLICATION
This application claims under 35 U.S.C. §119(a) the benefit of Korean Patent Application No. 10-2015-0126541 filed in the Korean Intellectual Property Office on Sep. 7, 2015, the entire contents of which are incorporated herein by reference.
BACKGROUND
(a) Field of the Invention
The present invention relates to an emergency braking force generation system and method for applying emergency braking force to a driving wheel through an engine and a transmission in the event a brake does not operate normally.
(b) Description of the Related Art
In general, a damping device of a vehicle is used to decelerate or stop a vehicle in motion to maintain the vehicle in a parked state. Usually, a friction-type brake, which converts kinetic energy into thermal energy by friction force and discharges the thermal energy to the outside, is used as the damping device.
The brake is largely divided into a foot brake mainly used when driving, and a hand brake used when parking. An operation apparatus is categorized as a mechanical type using a rod or a wire, and a hydraulic pressure type using a hydraulic pressure, and the main brake usually uses the hydraulic pressure type. In addition, an air brake using compressed air and a booster type of brake using intake back pressure or compressed air to reduce operating force may be provided.
The air brake using pressure of compressed air in order to compress a brake shoe on a drum is used in large trucks, buses, and trailers.
When a wheel is locked, riding comfort often is deteriorated. If a front wheel is locked, a steering state may be unstable, and if a rear wheel is locked, straight movement ability may be deteriorated. Therefore, an anti-lock brake system is provided in order to prevent the wheels from being locked
However, if an engine or a power device is in a state of unexpected impossible operation, a brake booster does not perform, and the brake enters an abnormal state. Accordingly, a serious traffic accident may occur. And if a master cylinder is in a non-operation state, hydraulic pressure for braking the vehicle is not applied, and thus supplying sufficient braking force may be difficult.
The related art includes Korean Laid Open patent No. 10-2014-0094292 and Korean Patent Application No. 10-1996-0053644.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.
SUMMARY
The present invention provides an emergency braking force generation system and method for applying emergency braking force to a driving wheel through a cooling fan, an engine, and a transmission in the event a brake does not operate normally.
As described above, an emergency braking force generation system according to an exemplary embodiment of the present invention may include: an engine for performing combustion using air and fuel injected from an injector and generating torque; a cooling fan which is rotated by the torque of the engine and configured to supply air into one side of the engine; a cooling fan clutch configured to selectively transmit the torque of the engine into the cooling fan; a transmission configured to vary a gear ratio by receiving the torque of the engine and rotate a driving wheel; and a control portion configured to control the cooling fan clutch such that the cooling fan is integrally rotated with the engine when an emergency braking signal is generated so as to increase a load of rotation of the engine through the cooling fan.
When the emergency braking signal is generated, the control portion may turn off the injector in order to stop injecting the fuel.
When the emergency braking signal is generated, the control portion may control the transmission to be shifted to a first gear or a second gear.
The control portion may generate the emergency braking signal based on an operation signal and a vehicle running speed.
When the emergency braking signal is generated, the control portion may control the engine and the transmission such that the torque of the driving wheel is transmitted to the engine through the transmission.
The cooling fan clutch, the transmission, and the driving wheel may be sequentially disposed on one torque transmission route.
An emergency braking force generation method according to an exemplary embodiment of the present invention may include: sensing an emergency braking signal; and integrally rotating the engine and cooling fan when it is determined that the emergency braking signal is generated by operation of the cooling fan clutch which is positioned on a torque transmission route between the engine and the cooling fan.
The emergency braking force generation method may further include stopping fuel injection by controlling an injector which is disposed at the engine.
The emergency braking force generation method may further include lowering a shift-speed of a transmission which varies and outputs a gear ratio by receiving torque of the engine.
If an operation signal of a brake pedal is sensed, then the engine and the cooling fan may be integrally rotated.
A non-transitory computer readable medium containing program instructions executed by a processor can include: program instructions that sense an emergency braking signal; and program instructions that integrally engage an engine with a cooling fan in a maximum rotation speed when it is determined that the emergency braking signal is generated by operation of the cooling fan clutch which is positioned on a torque transmission route between the engine and the cooling fan.
Therefore, when a damping device of the vehicle is out of order, the present invention may maximize emergency braking force transmitted to the driving wheel by maximizing rotation load of the cooling fan, the engine, and the transmission.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram of an emergency braking force generation system according to an exemplary embodiment of the present invention.
FIG. 2 is a block diagram illustrating an emergency assistance braking force generation method according to an exemplary embodiment of the present invention.
FIG. 3 is a flowchart illustrating an emergency assistance braking force generation method according to an exemplary embodiment of the present invention.
DETAILED DESCRIPTION OF THE EMBODIMENTS
It is understood that the term “vehicle” or “vehicular” or other similar term as used herein is inclusive of motor vehicles in general such as passenger automobiles including sports utility vehicles (SUV), buses, trucks, various commercial vehicles, watercraft including a variety of boats and ships, aircraft, and the like, and includes hybrid vehicles, electric vehicles, plug-in hybrid electric vehicles, hydrogen-powered vehicles and other alternative fuel vehicles (e.g. fuels derived from resources other than petroleum). As referred to herein, a hybrid vehicle is a vehicle that has two or more sources of power, for example both gasoline-powered and electric-powered vehicles.
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 the 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, specify 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, operations, elements, components, and/or groups thereof. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. Throughout the specification, unless explicitly described to the contrary, the word “comprise” and variations such as “comprises” or “comprising” will be understood to imply the inclusion of stated elements but not the exclusion of any other elements. In addition, the terms “unit”, “-er”, “-or”, and “module” described in the specification mean units for processing at least one function and operation, and can be implemented by hardware components or software components and combinations thereof.
Further, the control logic of the present invention may be embodied as non-transitory computer readable media on a computer readable medium containing executable program instructions executed by a processor, controller or the like. Examples of computer readable media include, but are not limited to, ROM, RAM, compact disc (CD)-ROMs, magnetic tapes, floppy disks, flash drives, smart cards and optical data storage devices. The computer readable medium can also be distributed in network coupled computer systems so that the computer readable media is stored and executed in a distributed fashion, e.g., by a telematics server or a Controller Area Network (CAN).
An exemplary embodiment of the present invention will hereinafter be described in detail with reference to the accompanying drawings.
FIG. 1 is a schematic diagram of an emergency braking force generation system according to an exemplary embodiment of the present invention.
Referring to FIG. 1 , an emergency braking force generation system includes a cooling fan 100 , a fan clutch 110 , an engine 120 , an injector 122 , a torque transmission route 124 , a transmission 130 , a driving wheel 140 , and a control portion 150 .
The engine 120 injects a fuel at the injector 122 , and torque is generated by combustion using the injected fuel and air.
Some of the torque generated at the engine 120 is transmitted to the cooling fan 100 through the cooling fan clutch 110 and transmitted to the driving wheel 140 through the transmission 130 along the torque transmission route 124 .
Conversely, if the engine brake is operated, the torque of the driving wheel 140 is transmitted to the engine 120 along the torque transmission route 124 , and the torque transmitted to the engine 120 is transmitted to the cooling fan 100 through the cooling fan clutch 110 .
The control portion 150 may control the cooling fan clutch 110 , the injector 122 of the engine 120 , and the transmission 130 , respectively.
The control portion 150 may be realized by at least one microprocessor activated by a predetermined program, and the predetermined program can be programmed to include a set of instructions to perform steps in a method according to an exemplary embodiment of the present invention, which will be described in more detail later.
FIG. 2 is a block diagram illustrating an emergency assistance braking force generation method according to an exemplary embodiment of the present invention.
Referring to FIG. 2 , a driving condition including a vehicle speed and a braking signal of the brake is inputted into a brake control portion 200 , and an emergency braking signal is generated according the inputted driving condition.
If it is determined that the emergency braking signal is generated, then the control portion 150 controls the cooling fan clutch 110 , the transmission 130 , and the injector 122 of the engine 120 .
The control portion 150 operates the cooling fan clutch 110 to increase a rotation load of the cooling fan 100 , and lowers a shift-speed of the transmission 130 . For example, the control portion may adjust the transmission to be shifted to a first gear or a second gear to increase the rotation load. In addition, the engine 120 turns off the injector 122 to cut off fuel injection.
Therefore, the cooling fan 100 , the engine 120 , and the transmission 130 may generate emergency braking force through the torque transmission route 124 by increasing the rotation load to a side of the driving wheel 140 .
The cooling fan 100 may generate about 50 kW of emergency braking force according to an exemplary embodiment of the present invention.
FIG. 3 is a flowchart illustrating an emergency assistance braking force generation method according to an exemplary embodiment of the present invention.
Referring to FIG. 3 , in step S 300 , an operation signal of a brake pedal (not shown) is sensed. Thereafter, the driving condition is sensed in step S 310 , and the driving condition such as a vehicle speed and deceleration may be calculated in step S 320 .
In step S 330 , it is determined that a braking system is in a failure state. According to an exemplary embodiment of the present invention, whether the braking system is in a failure state or not is established via parameters known to those skilled in the art and the detailed description is not provided.
If the braking system is in a failure state in step S 330 , and the operation signal of brake pedal is sensed in step S 300 , then the emergency braking signal is generated in step S 340 .
In step S 350 , the control portion 150 lowers a shift-speed of the transmission 130 . In other words, the shift-speed is shifted to a first gear or a second gear, and in step S 352 , the control portion 150 turns off the injector 122 to cut off fuel injection. Further, in step S 354 , the control portion 150 operates the cooling fan clutch 110 to integrally rotate with the engine 120 .
In step S 360 , accordingly, the braking force is applied to the driving wheel 140 by the cooling fan 100 , the engine 120 , and the transmission 130 . The driving wheel 140 is controlled to integrally rotate with the transmission 130 , the engine 120 , and the cooling fan clutch 110 according to an exemplary embodiment of the present invention. Therefore, performance of the engine brake may be improved. Moreover, when a damping device of the vehicle is out of order, the present invention may maximize emergency braking force transmitted to the driving wheel by maximizing rotation load of the cooling fan, the engine, and the transmission.
While this invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments. On the contrary, it is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.
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An emergency braking force generation system includes: an engine for performing combustion using air and fuel injected from an injector and generating torque; a cooling fan which is rotated by the torque of the engine and supplies air into one side of the engine; a cooling fan clutch that selectively transmits the torque of the engine into the cooling fan; a transmission that varies a gear ratio by receiving the torque of the engine and rotates a driving wheel; and a control portion that controls the cooling fan clutch such that the cooling fan is integrally rotated with the engine when an emergency braking signal is generated so as to increase a load of rotation of the engine through the cooling fan.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention deals with the field of devices for controlling boat lift apparatus. Boat lift apparatus is used normally adjacent large bodies of water for removing a boat or other watercraft from the water to an elevated position for storage. This is normally controlled by a cable mechanism attached to the boat lift apparatus.
This boat lift cable must be accurately controlled for movement and the present invention provides a double reduction gear drive for powering movement of such boat lifting cables which is significantly improved since it utilizes direct engagement of gearing rather than chains or pulleys or other remote means for connecting rotating shafts. Also the mutual orientation of the axis of the input shaft, the internal shaft, the output shaft and the winding spool provide a distinct improvement over the prior art since lubrication is significantly enhanced and smaller sized designs can be utilized. The maintenance requirements for chain and belt drive systems is problematic in the relatively harsh environments that are normally experienced at the locations where such boat lifts are utilized. For this reason the use of a direct drive double reduction gear mechanism is a significant enhancement over the prior art.
2. Description of the Prior Art
Various prior art devices have been utilized for the purposes of controlling movement of boat lifting mechanisms such as shown in U.S. Pat. No. 3,191,389 patented Jun. 29, 1965 to J. B. Poe on a “Boat Lift”; and U.S. Pat. No. 3,265,024 patented Aug. 9, 1966 to C. W. Kramlich on a “Boat Lift”; and U.S. Pat. No. 3,504,502 patented Apr. 7, 1970 to L. H. Blount on a “Lift Dock For A Water Borne Vessel”; and U.S. Pat. No. 3,675,258 patented Jul. 11, 1972 to Bradley M. Osmundson on a “Boat Hoist”; and U.S. Pat. No. 3,778,855 patented Dec. 18, 1973 to Nikolai Kariagin et al and assigned to Whittaker Corporation on a “Telescopic Gravity Davit”; and U.S. Pat. No. 3,791,229 patented Feb. 12, 1974 to Heinz Litezki and assigned to Schiess Aktiengesellschaft on a “Lifting Device For Lifting And Lowering Heavy Loads”; and U.S. Pat. No. 4,337,868 patented Jul. 6, 1982 to Narahari Gattu and assigned to Harnischfeger Corporation on a “Telescopic Crane Boom Having Rotatable Extend/Retract Screws”; and U.S. Pat. No. 4,589,800 patented May 20, 1986 to Charles L. Nasby, Jr. on a “Dock Structure And Method And Apparatus For Raising And Lowering Same”; and U.S. Pat. No. 4,641,996 patented Feb. 10, 1987 to Morton Seal on a “Side Loading Boat Lifts”; and U.S. Pat. No. 4,686,920 patented Aug. 18, 1987 to James L. Thomas on a “Cradle Type Boat Lifts”; and U.S. Pat. No. 4,954,011 patented Sep. 4, 1990 to Samuel H. Stenson on a “Powered Method And Apparatus For Lifting A Boat”; and U.S. Pat. No. 4,983,067 patented Jan. 8, 1991 to David M. Montgomery on a “Boat Lift Apparatus”; and U.S. Pat. No. 5,020,463 patented Jun. 4, 1991 to Robert E. Franklin et al on an “Arrangement For Raising Or Lowering Boats Or The Like”; and U.S. Pat. No. 5,051,027 patented Sep. 24, 1991 to George F. Horton on a “Boat Lift”; and U.S. Pat. No. 5,090,842 patented Feb. 25, 1992 to David M. Montgomery on a “Boat Lift Apparatus And System”; and U.S. Pat. No. 5,140,923 patented Aug. 25, 1992 to Kevin L. Wood on a “Raising And Lowering Device”; and U.S. Pat. No. 5,211,124 patented May 18, 1993 to John N. Reiser and assigned to Triton Corporation on a “Winch Construction For Boat Lift”; and U.S. Pat. No. 5,261,347 patented Nov. 16, 1993 to Peter W. Mansfield on a “Sailboat Davit”; and U.S. Pat. No. 5,287,821 patented Feb. 22, 1994 to Byron L. Godbersen on an “Electric Drive Mechanism For Boat Hoist Winch”; and U.S. Pat. No. 5,390,616 patented Feb. 21, 1995 to Henry Roth on a “Dock Mounted Small Boat Lifting System”; and U.S. Pat. No. 5,593,247 patented Jan. 14, 1997 to James A. Endres et al and assigned to Endcor Inc. on a “Programmable Boat Lift Control System”; and U.S. Pat. No. 5,687,663 patented Nov. 18, 1997 to Noel D. Wahlstrand on a “Boat Lift Transport Apparatus”; and U.S. Pat. No. 5,701,834 patented to Richard A. Lyons on Dec. 30, 1997 on a “Lift For Watercraft”; and U.S. Pat. No. 5,755,529 patented May 26, 1998 to R. R. Brad Follett on a “Boat Lift”; and U.S. Pat. No. 5,769,568 patented Jun. 23, 1998 to David G. Parkins et al and assigned to ABL Boat Lifts on an “Adaptable Boat Lift”; and U.S. Pat. No. 5,772,360 patented Jun. 30, 1998 to Donald M. Wood, II on a “Topless Watercraft Lifting Apparatus With A Differential Gearing System”; and U.S. Pat. No. 5,803,003 patented Sep. 8, 1998 to Robert V. Vickers and assigned to The Louis Berkman Company on a “Rotary Boat Lift”; and U.S. Pat. No. 5,915,877 patented to Charles L. Sargent et al on Jun. 29, 1999 and assigned to Quality Boat Lift, Inc. on a “Positive Drive Boat Lift”; and U.S. Pat. No. 5,934,826 patented Aug. 10, 1999 to Peter W. Mansfield on a “Boat Lift Apparatus”; and U.S. Pat. No. 5,947,639 patented Sep. 7, 1999 to Richard B. Bishop et al on a “Boat Lift Apparatus”; and U.S. Pat. No. 5,957,623 patented to Charles L. Sargent et al on Sep. 28, 1999 and assigned to Quality Boat Lifts Inc. on an “Electrically Insulated Positive Drive Boat Lift”; and U.S. Pat. No. 5,988,941 patented Nov. 23, 1999 to Charles L. Sargent et al and assigned to Quality Boat Lifts, Inc. on a “Boat Lift Cable Lock Apparatus”; and U.S. Pat. No. 6,006,687 patented Dec. 28, 1999 to Jeffrey M. Hillman et al and assigned to Marine Floats, Inc. on a “Modular Floating Boat Lift”; and U.S. Pat. No. 6,033,148 patented Mar. 7, 2000 to Lynn P. Norfolk et al and assigned to Norfolk Fabrication, Inc. on a “Housing For A Boat Lift Motor, Pulley And Gear Drive”; and U.S. Pat. No. 6,122,692 patented Feb. 8, 2000 to Lynn P. Norfolk et al and assigned to Norfolk Fabrication, Inc. on a “Housing For A Boat Lift Motor Pulley And Gear Drive” and U.S. Pat. No. 6,122,994 patented Sep. 26, 2000 to Lynn P. Norfolk et al and assigned to Norfolk Fabrication, Inc. on a “Housing For A Boat Lift Motor, Pulley And Gear Drive”; and United States Design Patent No. Des. 390,188 patented Feb. 3, 1998 to Lynn P. Norfolk et al and assigned to Norfolk Fabrication, Inc. on a “Boat Lift Motor And Gear Housing”.
SUMMARY OF THE INVENTION
The present invention provides a double reduction gear drive device for powering movement of a boat lifting cable which includes a main housing defining a main housing chamber therein. The main housing also preferably defines an input aperture and an output aperture therein both in fluid flow communication with respect to the main housing chamber.
An input shaft is also included rotatably mounted with_respect to the main housing and extending through the input aperture into the main housing chamber. A primary input shaft bearing is also included mounted in the main housing immediately adjacent the input aperture. This primary input shaft bearing is adapted to receive the input shaft extending therethrough to facilitate rotational movement thereof relative to the main housing.
A secondary input shaft bearing may also be included mounted in the housing spatially disposed from the primary input shaft bearing and adapted to receive the input shaft therethrough in order_to facilitate rotational movement thereof relative to the main housing.
An input gear is also preferably included secured to the input shaft at a position within the main housing chamber. An internal shaft is rotatably movably mounted within the main housing chamber of the main housing in a position extending approximately parallel to the input shaft and slightly displaced laterally therefrom. This input shaft and the internal shaft are both oriented in a generally vertically plane parallel with respect to one another.
A main internal gear may be also included secured on the internal shaft to be rotatable therewith. This main internal gear is preferably in engagement with respect to the input gear in such a manner as to be rotatably driven responsive to rotation of the input gear. The main internal gear is preferably larger than the input gear in order to cause the internal shaft to rotate at a rotational speed less than the rotational speed of the input shaft. A first internal shaft bearing may also be mounted within the main housing in such a manner as to receive the internal shaft extending therethrough to facilitate rotational movement thereof relative to the main housing. Similarly a second internal shaft bearing may be mounted within the main housing spatially disposed from the first internal shaft bearing. It is adapted to receive the internal shaft extending therethrough to facilitate rotation thereof relative to the main housing.
A worm gear is also preferably included secured on the internal shaft for rotation therewith. This worm gear is positioned at an intermediate position on the internal shaft spatially disposed from the main internal gear.
A main bearing journal is also preferably fixedly mounted within the main housing chamber. Preferably the second input shaft bearing and the first internal shaft bearing are both mounted in the main bearing journal and maintained thereby spatially disposed from one another to maintain fixed positioning thereof relative to the main housing.
An output shaft is also movably mounted within the main housing chamber of the main housing to be rotatable with respect thereto. The output shaft is positioned to also extend outwardly through the output aperture. The output shaft and the internal shaft are preferably oriented in a generally vertically extending plane and are oriented approximately perpendicular with respect to one another. The output shaft is partially positioned within the main housing and extends outwardly therefrom through the output aperture. A first output shaft bearing and a second output shaft bearing are also mounted within the main housing spatially disposed from one another and adapted to receive the output shaft extending therethrough to facilitate rotational movement thereof relative to the main housing.
An output gear is secured to the output shaft to be rotatable therewith and is positioned in engagement with respect to the worm gear to move therewith. The output gear is preferably larger than the worm gear to cause the output shaft to rotate at a rotational speed less than the rotational speed of the internal shaft.
A boat lifting cable spool is attached to the output shaft outside of the main housing chamber and is rotatable therewith to control winding of one or more boat lifting cables thereon. The boat lifting cable spool extends generally horizontally preferably and approximately perpendicular with respect to the internal shaft and the input shaft.
A drive means is operatively coupled with respect to the input shaft to selectively drive it. In this manner it will cause rotation of the boat lifting cable spool with enhanced torque and lower rotational velocity than the drive means itself in order to control movement of the boat lifting cable. The drive means preferably includes a drive shaft extending outwardly therefrom and being rotationally driven therewith. The drive shaft is coupled to the input shaft for selectively causing rotation thereof.
A boat lifting cable can also be included in a position secured to the boat lifting cable spool for controlling winding thereof on the spool. Two such boat lifting cables are normally utilized spaced apart on the spool.
A coupling means may also be attached to the drive shaft and the input shaft in order to cause simultaneous and similar movement therebetween. The coupling means preferably includes a key means positioned between the first drive shaft and the coupling means for securing them to one another. Another keying means is included positioned between the input shaft and the coupling for selectively securing them with respect to one another.
A coupling housing may also be included extending around the coupling itself. This coupling housing will preferably define a coupling chamber therein and a coupling input aperture and outlet aperture. The coupling housing is preferably securable with respect to the drive with the drive shaft thereof extending into the coupling through the coupling input aperture. The coupling also is preferably securable with respect to the main housing with the coupling aperture positioned in registration with respect to the main housing input aperture and with the input shaft extending through the coupling output aperture into the coupling chamber to a position adjacent the drive shaft. The coupling is preferably rotatably movable with respect to the coupling chamber and is secured to the drive shaft and input shaft to cause similar rotational movement. The coupling housing also includes a coupling bearing mounted therein immediately adjacent the coupling output aperture which is adapted to receive the input shaft therethrough to facilitate rotation thereof relative to the coupling housing.
The main housing of the present invention may include an enlarged wall section adjacent the first output shaft bearing in order to facilitate placement and lubrication thereof. Also the output gear may actually be configured as a helical flange gear as shown best in FIGS. 1 and 2 to facilitate engagement thereof with respect to the worm gear. Also the worm gear itself is preferably constructed with the teeth thereof having a lead angle of less than 7 degrees and 30 minutes in order to avoid backdriving thereof and enhance self-locking characteristics.
It is important to appreciate that the present invention is positionable with the two gear reduction mechanisms within a single housing. However, it is also contemplated within the scope of the present invention that the gear reduction mechanisms can each be positioned within their own housing. In this case the main overall housing can be defined as the composite of the two housings wherein the first step of gear reduction occurs in the first housing member and the second step of gear reduction occurs in the second housing member. This could be easily achieved merely by defining two separate housing members which comprise the overall housing itself with one set of reduction gears located in one housing and the second set of reduction gears located in a second immediately adjacent housing.
It is object of the present invention to provide a double reduction gear drive mechanism for powering movement of boat lifting cables wherein two steps of gear reduction are achieved with two sets of reducing gears in direct engagement with respect to one another thereby eliminating the need for any chain or belt operatively interconnecting the rotating shafts of the reduction means.
It is object of the present invention to provide a double reduction gear drive mechanism for powering movement of boat lifting cables wherein controlled operation of a boat lift is achieved.
It is object of the present invention to provide a double reduction gear drive mechanism for powering movement of boat lifting cables wherein a horizontally extending boat cable spool is operatively controlled for achieving full functionality of a boat lift.
It is object of the present invention to provide a double reduction gear drive mechanism for powering movement of boat lifting cables wherein lubrication is significantly enhanced.
It is object of the present invention to provide a double reduction gear drive mechanism for powering movement of boat lifting cables wherein two pairs of reduction gears are included which may be positioned within the same housing or may be separated and positioned within adjacent housings.
It is object of the present invention to provide a double reduction gear drive mechanism for powering movement of boat lifting cables wherein all reduction gearing is achieved by direct interconnection of gear teeth rather than use of any indirect connection such as chains and sprockets or V-belts and pulleys.
It is object of the present invention to provide a double reduction gear drive mechanism for powering movement of boat lifting cables wherein maintenance requirements are minimized.
It is object of the present invention to provide a double reduction gear drive mechanism for powering movement of boat lifting cables wherein parts replacement is greatly facilitated.
It is object of the present invention to provide a double reduction gear drive mechanism for powering movement of boat lifting cables wherein a drive means is connected through a direct drive to the boat lifting cable winding spool.
It is object of the present invention to provide a double reduction gear drive mechanism for powering movement of boat lifting cables wherein self-locking and anti backdriving is achieved by utilizing a worm gear with a lead angle of less than 7 degrees and 30 minutes.
It is object of the present invention to provide a double reduction gear drive mechanism for powering movement of boat lifting cables wherein no exposed mechanical parts extend outside of the housing means.
It is object of the present invention to provide a double reduction gear drive mechanism for powering movement of boat lifting cables wherein a one-piece gear housing can be utilized.
It is object of the present invention to provide a double reduction gear drive mechanism for powering movement of boat lifting cables wherein a compact low profile design provides an aesthetically pleasing external appearance.
It is object of the present invention to provide a double reduction gear drive mechanism for powering movement of boat lifting cables wherein capacities from 4500 lbs. to 120,000 lbs. are achievable.
It is object of the present invention to provide a double reduction gear drive mechanism for powering movement of boat lifting cables wherein the housing can be sealed to provide a totally maintenance free environment under certain conditions.
BRIEF DESCRIPTION OF THE DRAWINGS
While the invention is particularly pointed out and distinctly claimed in the concluding portions herein, a preferred embodiment is set forth in the following detailed description which may be best understood when read in connection with the accompanying drawings, in which:
FIG. 1 is a front cross-sectional view of an embodiment of the double reduction gear drive means of the present invention;
FIG. 2 is a top cross-sectional view of the embodiment shown in FIG. 1; and
FIG. 3 is a front perspective illustration of an embodiment of the double gear reduction drive means of the present invention showing the complete external housing thereof.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The present invention provides a means for controlling operation of a boat lift by accurately controlling the powering and operation of one more boat lifting cables 10 and 11 . The apparatus of the present invention preferably includes a main housing 12 which defines a main housing chamber 14 therein. Main housing chamber 14 is in fluid flow communication with respect to an input aperture 16 and an output aperture 18 both defined in the external surface of the main housing means 12 . The input aperture 16 is adapted to receive power thereinto and the output aperture 18 is designed to provide power outwardly therefrom. Preferably the output aperture 18 is spatially positioned away from the input aperture 16 .
The double reduction gear drive of the present invention preferably includes an input shaft 20 which extends through the input aperture 16 of main housing 12 and is rotatable with respect thereto. Preferably this rotation is achieved by having the input shaft 20 extend through a primary input shaft bearing 22 positioned immediately adjacent the input aperture 16 in the main housing 12 . A secondary input shaft bearing 24 is preferably positioned within the main housing chamber 14 . A main bearing journal 38 may be included in the main housing 12 within the main housing chamber 14 thereof and may be adapted to receive the secondary input shaft bearing 24 mounted therein. In this manner input shaft 20 will extend through the primary input shaft bearing 22 and through the secondary input shaft bearing 24 as well as through the input aperture 16 . Thus the input shaft 20 will be rotatably movable with respect to the housing and will extend from a position within the main housing chamber 14 through the input aperture 16 to a position external of the main housing chamber 14 .
An input gear 26 is preferably secured fixedly to the input shaft 20 at a position within the main housing chamber 14 .
An internal shaft 28 will preferably be contained entirely within the main housing 12 and will be positioned to be freely rotatable with respect to the main housing 12 by being mounted within a first internal shaft bearing 32 and a second internal shaft bearing 34 . Both shaft bearings 32 and 34 will be positioned within the main housing 12 with one preferably and optionally being positioned within the main bearing journal 38 at a position spatially disposed from the secondary input shaft bearing 24 mounted therein.
With the above-described configuration a main internal gear 30 is preferably fixedly mounted on the internal shaft 28 at a position immediately adjacent to the input gear 26 mounted on the input shaft 20 . As such, gear 30 and gear 26 are directly meshed with one another to provide direct gear powering therebetween. Thus, rotational movement of the input gear 26 will cause similar rotational movement of the main internal gear 30 . Preferably main internal gear 30 will be larger than the input gear 26 thereby achieving the first level of gear reduction desired by the apparatus of the present invention.
A worm gear 36 is mounted preferably at an intermediate location on the internal shaft 28 . Preferably the internal shaft 28 will include the first internal shaft bearing 32 mounted in the main bearing journal 38 and the second internal shaft bearing 34 mounted in the wall of the main housing 12 . Thus, rotation of the internal shaft 30 will cause similar rotation of the worm gear 36 .
An output shaft 40 is also preferably included in the apparatus of the present invention which will preferably extend through the output aperture 18 and be rotatably movable with respect thereto. Output shaft 40 will preferably be positioned within a first output shaft bearing 42 and a second output shaft bearing 44 both positioned within the main housing 12 and preferably within the wall area thereof. In a preferred configuration as shown in FIG. 2 the first output shaft bearing 42 will require the inclusion of an enlarged wall section 68 in the main housing 12 to allow sufficient clearance on both sides of an output gear 46 . Output gear 46 is a large preferably helical flange gear which requires significant clearance therearound for lubrication and effective operation thereof. The enlarged section 68 in the external wall of the main housing 12 helps achieve this purpose.
Helical flange output gear 46 is preferably in engagement with worm gear 36 . Since gear 46 is significantly larger than worm gear 36 the second stage of gear reduction is achieved by this direct drive gear connection. These two gears are intermeshed with respect to one another to achieve this solid reliable element of gear reduction. Preferably the second output shaft bearing 44 will be positioned immediately adjacent to and in registration with respect to the output aperture 18 of main housing 12 .
The output shaft 40 preferably will include a boat lifting cable spool 48 secured thereto at a location outside of the main housing 12 , external of the main housing chamber 14 . This spool will allow the boat lifting cables 10 and 11 to be wound therearound such that rotation of the output shaft 40 will cause similar rotation of the boat lifting cable spool 48 and allow operative control of positioning of the boat lifting cable 10 . In the preferred configuration the boat lifting cable spool 48 is shown with two boat lifting cables 10 and 11 mounted thereon, however the actual number of boat lifting cables can be one or more.
A drive means 50 may also be included in the present invention to provide powering for rotation of the input shaft 20 . This drive means 50 preferably includes a drive shaft 52 rotatably driven thereby and extending outwardly therefrom. A coupling 54 is preferably positioned adjacent the drive shaft 52 and preferably is fixedly secured thereto. Similarly the coupling 54 is preferably secured fixedly with respect to the input shaft 20 such that rotation of the drive shaft 52 will cause similar rotation of the input shaft 20 . The coupling between the drive shaft 52 and the coupling means 54 is achieved by a first keying means 56 . As shown in FIG. 1 this keying means can comprise a single keying stud. Similarly direct connection between the coupling 54 and the input shaft 20 can be achieved by a second keying means 58 which can comprise a plurality of splines. The specific configuration of the first keying means 56 and the second keying means 58 can be of any conventionally available keying means for achieving simultaneous rotation of a shaft and a collar, coupling or other member extending thereabout.
To protect the coupling 54 from the external environment a coupling housing 60 may extend therearound. Preferably coupling housing 60 defines a coupling chamber 62 therein in which the coupling 54 is located. Coupling housing 60 defines a coupling input aperture 64 through which the drive shaft 52 extends such that it can be keyed to the coupling 54 within the coupling chamber 62 . The coupling outlet aperture 70 defined in the coupling housing 60 is designed to receive the input shaft 20 extending therethrough such that it can reach to a position immediately adjacent the coupling 54 for engagement therewith. A coupling housing bearing 66 is preferably positioned within the coupling housing 60 at a position immediately adjacent to the coupling outlet aperture 70 thereof and preferably in registration therewith for the purpose of receiving the input shaft 20 extending therethrough for maintaining alignment between the coupling housing 60 and the main housing 12 . In order to achieve proper operation of the apparatus of the present invention the coupling output aperture 70 should be positioned in registration with respect to the input aperture 16 of the main housing 12 .
It should be appreciated that in the configuration of the present invention it is contemplated that various embodiments can include the positioning of the gear reduction elements in a single housing or in two separate housings. As shown best in FIG. 1 the main housing 12 can be divided by an interior housing wall 72 into a first housing member 74 containing the gear reduction resulting from engagement of input gear 26 and main internal gear 30 . A second housing member 76 can be defined also within the main housing member 12 which contains the gear reduction achieved by the engagement between the worm gear 36 and the output gear 46 . These two different pairs of gears can both be positioned within the same housing or in separate housings and, if they are positioned in separate housings, the construction which achieves the separate housing can be of many different varieties of possible configurations. One such configuration is shown by the dotted lining in FIG. 1 which shows the main bearing journal 38 extended outwardly to such an extent that it provides an internal wall or panel within the main housing chamber 14 which divides first housing member 74 from second housing member 76 . Thus, in this specific configuration, the main bearing journal 38 would not only contain bearings 24 and 32 but will also provide an interior housing wall 72 which minimizes fluid flow communication between the first housing member 74 and the second housing member 76 . This is one particular manner in which the gear reduction can occur in separate non-communicating chambers. The separation of each direct drive gear reduction mechanism is not necessary but is possible under various operating and application conditions. In a preferred configuration as shown in the solid line portions of FIGS. 1 and 2 both gearing reductions will occur within a single housing. Applicant has defined that housing as a main housing means such that it can comprise a single housing or multiple independent housings all of which come within the definition of a main housing means.
While particular embodiments of this invention have been shown in the drawings and described above, it will be apparent, that many changes may be made in the form, arrangement and positioning of the various elements of the combination. In consideration thereof it should be understood that preferred embodiments of this invention disclosed herein are intended to be illustrative only and not intended to limit the scope of the invention.
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A double gear reduction drive mechanism for powering movement of a boat lifting cable for moving of a watercraft upwardly from the water to an elevated position and downwardly from the elevated position of storage to a position in the water therebelow. The device includes two gear reduction mechanisms within the same housing or within separate adjacent housings which can be connected to a drive means for powering rotational movement of a cable spool with at least one boat lift cable attached thereto. This gear drive is a direct drive system since it does not include any belts, chains or pulleys but utilizes direct engagement between two immediately adjacently positioned pairs of gears each of which reduces rotational speed to effect an increase in power, torque and accurate control of movement of boat lifting cable.
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BACKGROUND OF THE INVENTION
The present invention relates to safety interlock devices responsive to fluid pressure in a system, and, more particularly, to safety interlock devices for inadvertently preventing the opening of an industrial pressure vessel containing a hazardous gas.
Various types of vessels are utilized for storing or transmitting hazardous gas. In a typical industrial installation, a cylindrical-shaped vessel may be provided with a wall-sized end cap. Such vessels may contain hydrogen sulfide, phosgene, or other hazardous fluids. Special safety precautions are obviously recommended to prevent the inadvertent release of gas, since the consequences of a leak may be life-threatening.
In order to accomplish inspection, maintenance, or repair operations, it may be necessary to remove the hazardous gas from the vessel and unthread the end cap for vessel access. In such a situation, cap removal is accomplished with an enormous cap retainer and threading device, and the operation, once commenced, cannot be easily and quickly reversed. If even low-pressure hazardous gas is present in the vessel, the release of gas during the cap unscrewing operation would subject nearby personnel to high risk. A conventional pressure indicator may be utilized to determine gas pressure or system pressure in such a vessel. Because of the hazardous nature of the gas, operating personnel are instructed not to unscrew the cap unless the pressure indicator reads "0" pressure.
In theory, such a pressure indicator should be sufficient to insure that no pressure is within the vessel, so that the cap removal operation may proceed without risking a hazardous gas exposure to nearby personnel. In practice, however, such a pressure indicator may provide insufficient assurances for operator safety in view of the hazardous nature of the gas. In particular, the pressure indicator may be defective and the reading inaccurate, or the indicator might not be sufficiently responsive to produce an accurate reading at a very low pressure, e.g., 2 psi. Moreover, even if the pressure indication reading were accurate, cap removal operators may have reason to doubt the reliability of the reading, or may erroneously assume that there is no pressure in the vessel and therefore neglect to read the indicator before commencing the cap removal operation. The interlocking device of the present invention is designed to provide additional protection against cap removal when the vessel contains either a high or relatively low pressure fluid.
The concept of a pressure-responsive interlock device is known in the art, as illustrated in the brochure entitled "MODCO Pipeline Hinged Closures", No. 1-84 5M, distributed by Modco Industries, Inc. The above interlock has, however, disadvantages which limit its acceptance in the industry. When under high system pressure, it may be very difficult, although possible, to manually override the interlock and open the cap. More importantly, the effort required to deactivate the interlock device when under low system pressure, e.g., 1-5 psi, is non-existent or barely existent Should the operator observe a minimal resistance upon moving the cover down, he must subjectively determine whether that resistance is due to a low fluid pressure in the vessel, or due to increased friction of moving parts because of corrosion or "plugging" of the device. Also, the same motion is utilized to both deactivate the interlock and hopefully notice the resistance presumably indicative of low pressure gas, and this downward cover movement may occur so rapidly that no operator thought occurs while the action is accomplished. The device provides no visual indication that system pressure has moved the device into the interlock position, so that the deactivation procedure is attempted regardless of the system pressure in the vessel. The device as described above can thus be intentionaly or unintentionally manually overriden, thus obviating its interlock capability and subjecting cap removal operators to high risk.
The disadvantages of the prior art are overcome by the present invention, and an improved pressure responsive safety interlock is hereinafter disclosed for preventing the opening of a closure. The device has particular utility for industrial pressure vessels containing hazardous gases, and provides additional safety for operators so that the vessel cap will not be inadvertently removed when the vessel contains a pressurized gas.
SUMMARY OF THE INVENTION
The pressure-responsive safety interlock prevents opening of a pressure vessel cap or closure. The device is ideally suited for use with an industrial vessel adapted for containing a hazardous fluid, and restricts opening of the closure if there is residual pressure in the vessel. The interlock body may be threaded to the vessel, thereby exposing an entrance port to vessel pressure. A chain may connect the interlock stem to the threaded vessel cap, so that the stem must be removed from the body to allow unthreading of the vessel cap.
Pressure in the vessel causes a piston in the interlock body to move to a lock position, so that the stem cannot be unthreaded from the body. The end of the piston may protrude from the interlock body to provide a visual indication that the piston is in the lock position indicative of at least residual pressure in the vessel. Once residual pressure is bleed from the vessel, the piston may be either manually or automatically returned to its unlock position, so that the stem may thereafter be removed from the body.
In an alternate embodiment, the primary locking piston may be secured in the lock position by a secondary piston and a plurality of balls positioned in a keyway. This embodiment has the advantage of a manual override capability only when there is no vessel pressure, and also has the advantage of a visual indication that the piston is in the lock position.
The interlock device of the present invention increases the safety procedure involved in removing a cap or closure from a pressure vessel. A visual indication of vessel pressure may be provided, so that the cap removal operation will not be attempted if residual pressure exists. Either manual or automatic positioning of the piston to the unlock position may be provided, although in the former embodiment, the manual interaction is a separate operation from the stem removal, thus substantially decreasing the likelihood of an operator inadvertently removing the stem when residual pressure exists. Moreover, in an embodiment having the capability of manually positioning the primary locking piston, a secondary pressure-responsive piston may be provided to secure the primary position in its lock position when at least residual pressure exists.
These and other features and advantages of the present invention will become apparent from the following detailed description, wherein reference is made to the Figures in the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a simplified pictorial view of a portion of a pressure vessel including an end cap, and further depicting two illustrative safety interlock devices according to the present invention.
FIG. 2 is a side view, partially in cross-section, of a suitable safety interlock according to the present invention.
FIG. 3 is a side view, partially in cross-section, of an alternate embodiment of a portion of the interlock depicted in FIG. 2.
FIG. 4 is a simplified side view, partially in cross-section, of an alternate embodiment of the present invention.
FIG. 5 is a side view, partially in cross-section, of a portion of the apparatus depicted in FIG. 4 in the lock position.
DETAILED DESCRIPTION
FIG. 1 depicts an industrial pressure vessel 10 having a generally cylindrical configuration for retaining a pressurized fluid. A large end cap 12 is threaded for sealed engagement with the end of vessel 10, and typically may have a diameter of 6 feet or greater and weigh in excess of several tons. A large cap retainer and threading device (not depicted) may be utilized for unthreading the cap 12 from the vessel 10 in order to obtain access to the interior of the vessel for inspection, repair, or service operations. The vessel 10 is suitable for housing a hazardous gas, and accordingly cap 12 should not be removed unless the hazardous gas is first removed from the vessel. In addition to the risk of operator exposure to hazardous gas, the existence of pressure within the vessel during a cap removal operation may subject adjacent operators and equipment to injury or serious damage if system pressure in the vessel suddenly and forcefully breaks the cap free from the vessel. A standard pressure gauge 13 may therefore be provided on the vessel, and operators are instructed not to remove the cap 12 unless gauge 13 indicates that there is no pressure in the vessel 10.
The safety interlock 14 of the present invention provides additional assurance that the cap 12 will not be inadvertently removed when at least nominal pressure, i.e., in excess of 1 psi, is within the vessel. As explained below, the device 14 is typically threaded to the vessel, and stem 22 is removable from device 14. A suitable linking member or stop means, such as chain 16, physically interconnects the cap 12 and the stem 22, so that the chain 16 prohibits unthreading of the cap unless the stem 22 is first removed from the device 14. The stem 22 cannot be removed from the device, however, if there exists pressure within the vessel. Accordingly, interlock 14 provides an additional measure of protection to ensure that the cap operators will not mistakenly attempt to remove cap 12 if there is at least nominal pressure within the vessel. It should be understood that the linking member 16 provides a positive barrier to cap removal unless the stem 22 is removed from the device in the sense that the operator is forced to recognize that the cap should not be unthreaded unless the stem 22 is first removed. From a structural standpoint, the chain 16 need not be designed to withstand the maximum torque that may be exerted on the cap, since the existence of a chain connected to the stem within the device 14 would provide the clearly recognizable notice that cap removal should not be attempted.
FIG. 1 also depicts another embodiment of the invention including device 18 having a stem 24 protruding therefrom. For the present, it may be assumed that the device 18 may be of the general type described above. However, the chain 16 has been replaced with arm 20 rigidly secured to the cap 12. The arm 20 is situated so as to engage the stem 24, which acts as a stop. If the stem 24 is removed from the device 18, the arm 20 may pass by the device 18 and the cap may be unthreaded from the vessel. In practice, only one interlock device according to the present invention will typically be provided for each enclosure 12, although two such devices are depicted in FIG. 1 to illustrate alternate embodiments of the invention which accomplish the same desired result.
FIG. 2 depicts a cross-sectional view of the interlock device 14 shown in FIG. 1. Primary components of the device include body 30, cap 32, stem 34, and piston 36. Entrance port 38 is provided for establishing fluid communication with pressure in vessel 10, and passageways 48 and 50 in body 30 enable fluid communication between the vessel and the piston chamber 52 in the body. The lower portion 40 of stem 34 includes an O-ring sealing member 42 for prohibiting loss of fluid pressure from the device. A cone-shaped end member or valve 44 is carried by the stem and is adapted for sealing engagement with the seating surface 45 in the body. If desired, a plastic sealing member or O-ring 46 may be provided to further ensure that the valve member 44 is in sealing engagement with seat 45, and thereby seal the piston chamber 52 from the vessel fluid.
Piston 36 is preferably provided with a stem passageway 56 having a cross-section slightly larger than the portion 40. O-ring seal 54 provides sealing engagement between the piston and the body, so that pressure in cavity 52 forces piston 36 to the lock position as shown in FIG. 2. In this position, the passageway surface 68 of the piston is in engagement with the portion 70 of the stem, and shoulder surface 66 of portion 40 is in position for engagement with surface 64 of the piston to prevent removal of the stem from the body 30.
The end cap 32 is connected to the body 30 by threads 33, and includes an aperture for receiving indicator portion 58 of the piston. The portion 58 protrudes from the end cap when the piston is in the lock position, and provides a visual indication to the operator that at least nominal pressure is in the vessel. The protruding portion of the member 58 may be painted to highlight this visual indication to the operator. Seals 54 and 52 seal the stem passageway 56 from vessel pressure, and seal 62 need only be a dust prevention seal.
The lower fluid entrance portion 80 of body 30 is provided with threads 81, and the device may thus be sealingly coupled to the vessel 10. During its normal interlock mode, portion 72 of the stem will be threaded to the body at 74, so that the conical member 44 seals the passageway 48 from the interior of the vessel. Body threads 74 thus define a stem port opposite port 30 with respect to the piston chamber, so that the stem 34 can only be axially removed from the body by an unthreading operation. The interior of the safety device need not be continually subjected to either fluid from within the vessel or fluid pressure from the vessel, thereby prolonging the life of the device and reducing the likelihood of plugging. Unless and until cap removal 12 is desired, various fluids may occupy vessel 10 without having any affect on the components downstream from seal 46, since those components may be sealed from fluid in the vessel.
Even an inexperienced operator would readily recognize that the cap 12 should not be removed if chain 16 is interconnecting the cap and the stem 22 is not removed from the body 30. If there is pressure in the vessel, piston 36 would be forced to the lock position as the operator begins to unthread the stem 34 from the body 30 and the seal with seat 45 is broken. The stem may thereafter be unthreaded until shoulder surface 66 engages the piston, whereby further unthreading of the stem is not possible. Once the piston moves to the lock position, indicator portion 58 will protrude from the end cap 32, thereby providing a visual indication of at least nominal pressure in the vessel.
As previously indicated, gauge 13 may inaccurately read zero pressure, and the operator may have reason to question whether there is in fact any pressure in the vessel. The operator may thus thread the stem to the position as shown in FIG. 2, and may thereafter press on the surface 60 of the piston in an attempt to manually override the piston and move it in the unlock or centered position. If no system pressure exists, the piston will move manually to the center position and will remain in that state so that the stem 34 may thereafter be removed from the body 30. If high system pressure exists, the operator will be unable to force the piston to the centered position and the stem could therefore not be removed. If a low or nominal pressure exists in the vessel, the operator may be able to force the piston to the centered position, but the operator should perceive a noticable resistance to this centering operation. Moreover, the piston will return to its lock position once the override force is released from the surface 60. Since the manual override or piston centering operation is distinct from the stem removal operation, the operator cannot with a single motion both manually override the device and deactivate the interlocking member of the device, i.e., remove the stem. Those skilled in the art will recognize that the above advantages will also be obtained if the operator threads the stem into sealed engagement with seat 45 before attempting the manual override operation. In this case, the fluid in the piston chamber must be compressed to center the position, and the subsequent stem unthreading operation will again move the piston into the lock position before the shoulder surface passes by the lower surface 64 of the piston.
A piston alignment pin 82 is provided for engaging the side walls of slot 84 in the piston, thereby preventing the piston from rotating within the piston chamber. Set screw 83 selectively locks the pin 82 in its desired position. Plugs 49 and 51 seal passageways 48 and 50, respectively, and may be removed to service the unit when the stem 34 is in sealed engagement with the seat 45. An axial piston position stop 55 limits travel of the piston in the unlock or centering direction, so that the passageway 56 will be aligned with the slightly smaller diameter portion 40 during the stem removal operation. A strap or chain 78 is secured to the top portion 76 of the stem, and serves as the cap interconnection member.
FIG. 3 depicts a portion of an alternate embodiment of the present invention, including a body and stem as previously described. A solid-face end cap 90 is threaded to the body at 92, so that the body and end cap enclose the modified piston 94 and prevent manual manipulation of the piston. The piston 94 is shown in FIG. 3 in the lock position, and a cavity 96 between the inner face of the cap 90 and the piston houses a biasing means or spring 98. The other components of the device, including those not depicted in FIG. 3, may be of the type previously described.
The spring 98 biases the piston 94 toward the unlock position. This biasing force is overcome when there is fluid pressure acting on the piston, so that the piston is moved to the lock position by fluid pressure in excess of any nominal amount. The advantage of the embodiment shown in FIG. 3 is that operator access for centering the piston is denied, and accordingly, the device cannot be manually overridden even under low system pressure. A disadvantage of this embodiment, however, is that a visual indication of the piston position is not provided. Piston access to otherwise ensure free or unencumbered manual piston manipulation is denied, and the piston could unknowingly become frozen in the unlock position. Moreover, should the unit become plugged and the piston freeze in the lock position, the spring force may not be sufficient to automatically return the piston to the unlock position although hazardous gas has been fully removed from the vessel.
The biasing force of spring 98 may be selected to be only slightly greater than the force required to bias the piston to the unlock position when there is no pressure in the vessel. Generally, the biasing force of spring 98 is in the range of from 1.5 lbs. to 10 lbs., and preferably from 2 lbs. to 7 lbs., so that only a nominal fluid pressure of 1 psi or less will be necessary to automatically move the piston to the lock position.
FIG. 4 depicts another embodiment of the present invention, including a body 102, end cap 104, stem 106, and a primary or locking piston 108. The piston 108 as shown in FIG. 4 is in the centered or unlock position, so that the lower portion 110 of the stem including O-ring 112 may be unthreaded from the body. Indicator portion 114 of the piston resides within an aperture provided in the end cap 104, with seal 116 protecting the interior of the body 102 from exposure to dust and moisture. In the unlock position, the end of indicator portion 114 may be flush with the outer surface of the end cap, or may be slightly recessed within the end cap, so that the operator may easily recognize that the piston is centered for removal of the stem.
FIG. 4 depicts a secondary piston 118 movable within the primary piston 108. In the unlock position, spring 121 biases the secondary piston 118 to a position away from the stem 106 and into engagement with snap ring 120 affixed to primary piston 108. Tapered annular grooves 122 and 124 may be provided along the inner surface of the body 102 and the outer surface of the secondary piston 118, and a plurality of holes 126 may be radially drilled through the wall of the piston 108 for receiving an equal number of ball members 128. By way of example, three holes 126 may be equally spaced along the circumference of the piston 108 for receiving three balls 128. Each ball member 128 has a diameter greater than the thickness of the primary piston wall, so that a portion of the ball member must be either in the groove 124 (when in the unlocked position) or in groove 122 (when in the locked position). Sealed engagement of the inner or secondary piston 118 with respect to the primary piston 108 is provided by O-ring 130.
When there is no pressure in cavity 134, spring 121 acting between the primary piston and the inner piston biases the inner piston in the position shown in FIG. 3 with ball members 128 residing partially in groove 124, and the primary piston 108 may be centered. When fluid pressure is transmitted to cavity 134, the primary piston 108 moves toward the stem 106, since the position of the secondary piston 118 is fixed relative to the primary piston by ball members 128 in groove 124. Once the ball members 128 are radially aligned with groove 122 and the primary piston is in the lock position, fluid pressure acting upon the secondary piston 118 will force the ball members out of the groove 124 and partially into groove 122 and, during this motion, compress spring 121. The cross-section of the secondary piston 118 is substantially greater than the primary piston 108, although fluid pressure acting on the secondary piston will be effectively transmitted to the primary piston to keep the primary piston in the lock state during this action. Movement of the secondary piston 118 toward the stem may continue until the arrangement in FIG. 5 is achieved, with the primary piston in the lock position, spring 121 compressed, and the entirety of the ball members 128 projecting outwardly from the outer diameter surface of the inner piston 118.
It may be seen in FIG. 5 that the indicator portion 114 projects from the end cap 104 when the piston 108 is in the lock position. If desired, the secondary piston 118 may abut the inner bottom surface of the cup-shaped primary piston 108, with the inner piston having a cylindrical aperture 136 for receiving spring 121. Port 138 may be provided so that fluid pressure in cavity 134 need not compress the gas between the primary and secondary pistons when moving toward the lock position. Plug 132 may be provided to obtain service access to the secondary piston, which may also contain a threaded bore 140 aligned with the plug 132. If necessary, the secondary piston could be manually engaged and returned to the position as shown in FIG. 4. This latter service operation may be required if the secondary piston inadvertently becomes frozen to the primary piston, and this service operation may be performed either with no pressure in the vessel or with the stem in sealing engagement with the seat provided in the fluid passageway to the piston cavity.
When there is no fluid pressure in the cavity 134, spring 121 may position the secondary piston so that the ball members 128 are aligned with slot 124, and the secondary piston is in engagement with the snap ring 120. The primary piston 108 may then be manually centered by pressing on the indicator portion 114, forcing the ball members out of the slot 122 and into the slot 124. The primary piston will then again be in a position as shown in FIG. 4.
An advantage of the embodiment as shown in FIGS. 4 and 5 is that a visual indication of the position of the primary piston is provided, and the primary piston may be manually centered by the operator if there is no pressure in the piston cavity. If pressure is in the piston cavity, however, the primary piston would be held in the lock position, and this position may not be manually overridden. Nominal pressure in the piston cavity will cause the secondary piston to be in the position as shown in FIG. 5, and it may be seen that the primary piston is locked in that position by ball members 128 and groove 120, and that pressing on projection 124 will not allow the operator to center the piston 108.
The cross-sectional area of piston 36 may be selected so that the piston will be moved to the lock position if pressure in excess of a nominal value, i.e., 1 psi, is in cavity 134. The apparatus of the present invention may thus perform its desired interlock function if pressure in excess of a selected nominal pressure exists in the vessel. Generally, this nominal pressure value will be less than 2 psi, and may be as low as 0.5 psi or even lower. Applicant has found that satisfactory performance may be obtained with a piston 36 having a cross-sectional area of approximately 2.7 square inches. Similarly, the combined cross-sectional area of pistons 108 and 118 may be in the range of from 2.5 to 3.0 square inches. Spring 121 may have the selected range of biasing force as described for spring 98.
A significant advantage of the present invention is that the passageway to the piston cavity may be manually plugged with member 42 to normally prohibit fluid pressure from the inner workings of the device, although this seal will necessarily be broken before the stem can be removed from the body. Although the life of the interior components of the interlock device is substantially increased in this manner, both the metallic components of the device as well as the sealing members may be fabricated from materials resistant to corrosion or substantial deterioration by hazardous fluids.
A key and keyway arrangement between the stem and the body could be provided for axially removing the stem, although the threaded operation disclosed herein is preferable since it requires a sufficient amount of time to ensure that the piston will be moved to the lock position to prohibit stem removal if at least nominal pressure is in the vessel. Means other than a flexible interconnection or a rigid bar may be provided for serving as a stop means to limit movement of the vessel end cap relative to the stem when within the interlock device. For instance, the end of the stem may be configured to serve as a key which must be inserted in a cap vessel lock in order to begin the cap removal operation. Also, the cap may be hinged or secured to the vessel by means other than threads, and the stop means between the stem and the cap may accordingly be altered to provide the same positive barrier benefit.
While the present invention has been disclosed in connection with the above illustrative embodiments, numerous modifications may be made without departing from the spirit or scope of the invention. It should therefore be understood that the embodiments described herein and shown in the accompanying Figures are exemplary only, and are not intended to limit the scope of the present invention.
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A safety interlock device is provided for preventing the opening of a vessel containing a pressurized fluid. In a typical application, the interlock device may be used in industrial applications to prevent the inadvertent unscrewing of a cap from the end of a large pressure vessel containing a hazardous gas. A pressure port end of the interlock body is adapted for threaded engagement with the vessel and is open to vessel pressure. A pressure-responsive locking piston movable within the body prohibits removal of a stem when vessel pressure exceeds a selected minimum pressure. A chain may be secured at each end to the stem and vessel cap, so that the cap cannot be unscrewed to open the container unless the stem is first removed. In one embodiment, the locking piston is prevented from manual override by the position of a second piston and a plurality of ball members locked in a groove.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application is a division of our copending application Ser. No. 807,692 filed June 17, 1977 now abandoned; which in turn was a division of our application Ser. No. 600,666 issued Aug. 30, 1977 as U.S. Pat. No. 4,045,422 filed July 31, 1975 as a continuation-in-part of our application Ser. No. 460,836 filed Apr. 15, 1974 now abandoned.
FIELD OF THE INVENTION
This invention describes novel ketals of various α-oximinoketones, methods for the preparation of these compounds and includes novel intermediates formed during the production thereof. This invention also discloses a novel class of α-nitrosoketal dimers, which can be regarded as the intermediates in the production of the corresponding α-oximinoketals, and particularly it discloses novel methods for the production of the said α-nitrosoketal dimers.
Beckman fragmentation of these novel ketals of α-oximino ketones, particularly those of α-oximinocyclohexanone, α-oximinocyclopentenone, α-oximinocyclooctanone, α-oximinocyclodecanone, etc. provides the corresponding alkyl ω-cyanoalkanoates which are convenient intermediates for the production of either cyclic lactams or polyamides and amino acids. Similarly, direct nitrosolysis of the corresponding α-nitrosoketal dimers provides the same alkyl ω-cyanoalkanoates as above.
SUMMARY OF THE INVENTION
The novel α-nitrosoketal dimers, which can be used as intermediates for the synthesis of the α-oximinoketals, may be characterized by the formula: ##STR1## which for convenience of notation will henceforth be written as: ##STR2## with an implicit understanding that the corresponding dimer may be either a dl-pair, or meso compound of either Z- or E-dimers where Z- and E- refer to the cis- or trans- configuration of the two oxygen atoms attached to the N═N grouping, wherein: R 1 and R 2 are selected from the group consisting of C 1 -C 10 alkyl or phenyl and/or combinations thereof, and R 3 and R 4 are independently selected from the group consisting of C 1 -C 10 alkyl, cyclohexyl and C 1 -C 4 alkyl substituted cyclohexyl radicals.
The novel ketals of α-oximinoketones described in the present invention may be characterized by the following formula: ##STR3## wherein: R 1 and R 2 are selected from the group consisting of C 1 -C 10 alkyl or phenyl and/or combinations thereof, or in combination together represent a part of the C 5 -C 12 cyclic ring structure; and X is a member of the group consisting of: ##STR4## wherein R 3 and R 4 are independently selected from the group consisting of C 1 -C 10 alkyl, cyclohexyl and C 1 -C 4 alkyl substituted cyclohexyl radicals.
Illustrative nitrosoketal dimers include: ##STR5##
Illustrative α-oximinoketal compositions include: ##STR6##
The novel dimer compositions of the present invention may be prepared by nitrosating alkoxyalkenes of the formula: ##STR7## wherein: R 1 and R 2 are selected from the group consisting of C 1 -C 10 alkyl or phenyl and/or combinations thereof, or in combination together represent a part of the C 5 -C 12 cyclic ring structure, and
R 3 is selected from the group consisting of C 1 -C 10 alkyl, cyclohexyl, and C 1 -C 4 substituted cyclohexyl radicals; with at least one molar equivalent of an alkyl nitrite of the formula
R.sup.4 ONO
either in the absence of other solvents, or in an inert solvent in either case in the presence of catalytic amounts of a suitable acid catalyst, wherein
R 4 is selected from the group consisting of C 1 -C 10 alkyl, cyclohexyl and C 1 -C 4 alkyl substituted cyclohexyl radicals, and isolating the dimer product(s) thus formed.
These dimers may be readily converted to the corresponding α-oximinoketals by isomerizing the dimers and isolating desired products.
However, in accordance with the method of the present invention, it is not necessary to isolate and purify the dimer product in order to produce the desired oximino ketal product. Thus, satisfactory yields of the α-oximinoketals may be obtained by nitrosating the previously described alkoxyalkenes either with an excess of an alkyl nitrite in the absence of other solvent, or in an inert solvent, removing the excess of alkyl nitrite, adding an inert solvent, isomerizing the remaining residue, and isolating the desired product.
In addition to producing these novel α-oximinoketals by nitrosating with alkyl nitrites and isomerizing, it is possible to perform the desired nitrosation using at least one molar equivalent each of a nitrosyl halide, a base and an alcohol of the formula R 4 OH where R 4 is as previously defined; and isolating the desired product.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In accordance with the method of the present invention, the novel α-nitrosoketal dimers are produced by the nitrosation of the corresponding alkoxyalkenes. The novel α-oximinoketals are produced either by isomerization of the corresponding nitroso dimers, or directly from the alkoxyalkenes by nitrosation and isomerization without isolation of the intermediates involved. Additionally, the novel cyclic ketals of α-oximinocyclohexanone can be produced directly from cyclohexanone by nitrosation in the presence of a suitable vicinal diol.
The alkoxyalkenes used as starting materials in this invention may be prepared using a variety of methods such as by the acid catalyzed elimination of the alcohol from the corresponding ketals, as represented by the equation: ##STR8## wherein R 1 , R 2 , R 3 and R 4 are as previously defined. Thus R 1 and R 2 may be any C 1 -C 10 alkyl radical, phenyl group, or in combination together may be a part of C 5 -C 12 cyclic structure.
The nitrosation of alkoxyalkenes may be carried out using at least one molar equivalent, preferably 3-10 molar equivalent of a suitable nitrosating reagent in the absence of other solvent and in the presence of a catalytic amount, preferably between 0.01-0.1 molar equivalent, of a suitable acid. Suitable nitrosating agents include alkyl nitrites of the formula R 4 OHO, where R 4 is as previously defined. The suitable acid catalysts are sulfur trioxide, sulfuric acid, oleum, boron trifluoride etherate, alkyldialkoxycarbonium fluoroborates, preferably boron trifluoride etherate or alkyldimethoxycarbonium fluoroborates.
Thus, preparation of the corresponding α-nitrosoketal dimers may be represented with the equation: ##STR9## wherein R 1 , R 2 , R 3 and R 4 are as previously defined. The nitrosation reaction may be carried out between -70°-+25°, preferably at -30°-0°, and would depend on particular system employed. The isolation of the nitroso dimer may be accomplished either by filtration or by evaporation of the excess of the alkyl nitrite used.
Alternatively, the nitrosation reaction with alkyl nitrites may be carried out in any suitable inert solvent using only one, preferably 1.10-1.20 molar equivalents of an alkyl nitrite and the suitable acid catalyst. Suitable solvents include ether, chloroform, organic sulfones, organic nitro compounds, etc., however, liquid sulfur dioxide is preferred. The amount of solvent employed should be sufficient to bring the desired course of the reaction. When solvents other than sulfur dioxide are employed, the presence of acid catalyst, e.g. sulfur trioxide, sulfuric acid, boron trifluoride etherate, is required; when sulfur dioxide is employed, such a catalyst is preferred but not essential to the course of the reaction.
The nitrosation with alkyl nitrites in the presence of a solvent may be carried out using a wide range of temperatures, depending on the solvent used and the nature of the alkyl nitrite. Using SO 2 as solvent, the preferred temperature range is between -30° and +25° C., although the temperature between the freezing and boiling points of the solvent could be used. Similarly, nitrosation with alkyl nitrites in the absence or in the presence of other solvent, may be carried out either at atmospheric pressure or higher, preferably between atmospheric pressure and 200 psi.
If recovery of the thus formed nitroso dimer is desired, it may be readily isolated by evaporation of the solvent (including the excess alkyl nitrite), in the presence of small amount of sodium bicarbonate or other base which is added to assure the neutralization of any acid catalyst used. The desired material is then recovered by filtering from a solvent in which the particular nitroso dimer has little or no solubility.
The isomerization of thus produced nitroso dimers to the corresponding α-oximinoketals may be carried out with or without the previously described isolation of the dimer. This isomerization may be accomplished using a variety of methods, and can be schematically represented by the following equations: ##STR10## wherein R 1 , R 2 , R 3 and R 4 are as previously described.
In accordance with the present invention, the dimer may be heated above its melting point until such time as the color of the melt changes from blue, indicative of the presence of the corresponding monomeric nitroso compound, to either colorless or slightly yellow. Subsequent cooling provides the desired α-oximinoketals which can be further purified by conventional technique.
Alternatively, the nitroso dimers may be isomerized by heating in solvents, such as pentane, benzene, heptane, toluene, methanol, ethanol, chloroform, etc., at a temperature below the melting point of the compound. A further isomerization procedure comprises a catalytic reaction using either inert or hydroxylic solvents as above in the presence of a catalytic amount of base. In this case the isomerization can be accomplished either at room temperature or by heating.
If the preparation of the nitroso dimer is carried out in a solvent and the dimer is not isolated, the isomerization can be achieved by heating the reaction mixture after completion of the nitrosation reaction, either in the presence of the acid catalyst used in the nitrosation reaction, or under slightly basic conditions after neutralization of the acid catalyst with various bases, such as metal alkoxides. Alternatively, in accordance with the preferred method, the sulfur dioxide or excess alkyl nitrite, is displaced by a solvent such as methanol, ethanol, pentane, benzene, heptane, toluene, or chloroform, and the isomerization is then achieved by heating, or as described above, in the presence of catalytic amount of base. In either case, the desired α-oximinoketal is isolated after removal of solvent, as for example, by crystallization.
In the case of nitrosation of alkoxyalkenes with a nitrosyl halide, preferably nitrosyl chloride, a corresponding halo substituted compound is formed as an intermediate which is then treated, without isolation, in the presence of at least one molar equivalent of each of base and an alcohol of the formula R 4 OH where R 4 is as previously defined. Preferably 2-3 molar equivalents of the alcohol are employed. Alternatively, the nitrosation reaction may be carried out in the presence of the alcohol, in which case the base is added after complete addition of the nitrosyl halide and worked-up as before.
Schematically, this reaction may be represented by the following equations using nitrosyl chloride as the nitrosating reagent. ##STR11## wherein R 1 , R 2 , R 3 and R 4 are as previously defined. This reaction may be carried out in any of the previously disclosed inert solvents; however, the preferred solvent for this particular reaction is ether. Suitable bases include sodium methoxide, pyridine, triethylamine, and preferably a solution of sodium hydroxide in the R 4 OH alcohol. The reaction temperature is not critical and preferably, when ether is used as solvent, will be between -20° and 30° C. Pressures within the range of one atmosphere to 200 psi may be employed. The reaction time is not critical and is selected to ensure complete reaction. After separation of the halide salt the reaction product, the corresponding α-oximinoketal, may be isolated by evaporation of the solvent and crystallization.
The invention will be further illustrated by the following Examples.
EXAMPLE 1
Production of 1,1-dimethoxy-2-nitrosocyclohexane dimer using excess of methyl nitrite as solvent
Methyl nitrite (125 g, 2.05 mole) was distilled into a 500 ml flask equipped with a mechanical stirrer, addition funnel, dry ice condenser, N 2 atmosphere and a bath maintained at -20° C. 20% Oleum (0.325 ml, 1 mole % based on amount of 1-methoxycyclohexene used) was added. 1-Methoxycyclohexene (75.4 g, 0.674 mole) was added dropwise over 2.5 hours with stirring. The reaction mixture was a heavy suspension of a white solid in a blue-green liquid. The catalyst was neutralized by sodium bicarbonate (6.5 g) with the addition of petroleum ether (b.p. 30°-60° C.) to facilitate stirring. Excess methyl nitrite was allowed to distill off, and the reaction mixture filtered and the white solid washed with petroleum ether. Evaporation of the filtrate in vacuum is carried out to recover partially dissolved product. The combined crude solid dimer, 113.8 g, was according to nmr analysis essentially pure 1,1-dimethoxy-2-nitrosocyclohexane dimer. The inorganic materials can be removed by dissolving the crude dimer in freshly distilled methylene chloride, filtering and removing the solvent at 0° C. Such a dimer is white powder m.p. 108°-110°.
EXAMPLE 2
Production of 1,1-dimethoxy-2-nitrosocyclohexane dimer
Methyl nitrite (29.75 g., 0.487 mole) was distilled into 250 ml. of sulfur dioxide maintained at -78° C. in a 1000 ml. three-neck flask equipped with a mechanical stirrer, an addition funnel-dry nitrogen inlet and a dry-ice/acetone condenser. Freshly distilled boron trifluoride-etherate (0.25 ml., 0.28, g., 2.0×10 -3 mole) was quickly added via syringe and the light yellow solution was warmed to -15° C. with a bath of dry ice/carbon tetrachloride. The nitrogen inlet was then placed in the condenser and 1-methoxycyclohexane (45.8 g., 0.407 mole) was added dropwise over 20 minutes to the stirred reaction mixture. After the addition was complete, stirring was continued for an additional 20 minutes at -15° C. and the deep blue-green solution rapidly turned a light yellow-green. The cooled (-78° C.) reaction mixture was quickly poured into 200 ml. of cold pentane containing sodium bicarbonate (1-2 g.) and then thoroughly evaporated at 20° C. The yellow-green gummy residue was triturated with several portions of pentane (150 ml. each) at 0° C., re-evaporated each time, and finally allowed to warm to room temperature under 300 ml of pentane with occasional swirling over 45 minutes. The off-white solid was filtered, rinsed with cold pentane, stirred with 150 ml. of water at 0° C. and then filtered and dried in vacuo to give 35.4 g. (50.1%) of the nitroso dimer, m.p. 108°-110° C.
EXAMPLE 3
(a) Preparation of Ethyldimethoxycarbonium Fluoroborate Catalyst*
In a dry reactor with an argon atmosphere, trimethylorthopropionate (b.p. 122°-125° C., 11.3 g., 84.3 moles) is cooled to -30° C. A mixture of BF 3 .Et 2 O (12.3 ml., 94.4 mmoles) and dry dichloromethane (10 ml.) is added over a 15 minute period with stirring. The reactor is warmed to ice-water bath temperature for 15 minutes. Dry ethyl ether (15 ml) is added and the reaction mixture is cooled to -70° C. The solvents are decanted from the solid, brown product which is then washed at -70° C. with a mixture of dichloromethane (10 ml.) and ethylether (10 ml.). After decantation, the product is dried at RT/<1 mm Hg to an off-white solid. It is dissolved in dichloromethane (30 ml) to a yellow-brown solution and stored at RT under a slight pressure of argon. Its concentration was determined to be two mmole/ml by the use of nmr and an internal standard (chloroform). When used as a catalyst an aliquot is removed by syringe. The structure ##STR12## was confirmed by nmr.
(b) 1,1-dimethoxy-2-nitrosocyclohexane dimer was prepared by the procedure described in Example 1 with the exception that one mole percent diethoxycarbonium fluoroborate was used as a catalyst. The essentially pure dimer was recovered as product and its structure was confirmed by IR and nmr.
EXAMPLE 4
1-Ethoxy-1-methoxy-2-nitrosocyclohexane dimer was prepared according to the procedure described in Example 1 from the reaction of 1-ethoxycyclohexene (20.4 g., 0.162 moles) and excess methylnitrite (2.5 g., 0.414 mole). In this instance, only about 25% of the dimer (5.9 g.) was recovered as precipitate with the major portion (18.9 g.) being recovered by flash evaporation of the wash liquors at 25° C. The recovered products were essentially the same and IR and nmr confirmed the structure as being essentially pure dimer.
EXAMPLE 5
1,1-Dimethoxy-2-nitrosocyclopentane dimer was prepared as in Example 1 by reacting 1-methoxycyclopentene (15.9 g., 0.162 mole) with an excess of methylnitrite (29.7 g., 0.48 mole) using 0.5 mole percent of 20% oleum as catalyst. The product (20.5 g.) was mostly the desired dimer with a small amount of 1,1-dimethoxy-2-oximinocyclopentane. An additional 5 grams of product were recovered by flash evaporation of the wash liquors. The structure was confirmed by IR and nmr.
When the product was allowed to stand for four days at room temperature in chloroform, it rearranged to 1,1-dimethoxy-2-oximinocyclopentane mp 79°-80° containing some methyl ester of 3-cyanobutyric acid.
EXAMPLE 6
Using the procedure described in Example 1, 1,1-dimethoxy-2-nitrosocyclooctane dimer was prepared by reacting 1-methoxycyclooctene (18.5 g., 0.132 mole) with an excess of methylnitrite (25 g., 0.406 mole) in the presence of one mole percent of 20% oleum (0.065 ml) as catalyst. The precipitated dimer (17.5 grams) was recovered in the usual manner and its structure was confirmed by IR and nmr. An additional amount (10.6 g.) of dimer was recovered by flash evaporation of the wash liquors at ice-water temperature.
EXAMPLE 7
Using the procedure described in Example 1, 1,1-dimethoxy-2-nitrosocyclododecane dimer was prepared by reacting 1-methoxycyclododecene (25.8 g., 0.132 mole) with an excess of methylnitrite (25 g., 0.406 mole) in the presence of one mole percent of 20% oleum (0.065 ml) as catalyst. The structure of the dimer recovered (27.4 g.) was confirmed by IR. This dimer was not soluble in chloroform, methanol, dichloromethane, 1,2-dichloroethane, isopropanol, DMSO, cyclohexane, nitromethane or benzene at room temperature. An additional 7 g. of product was recovered from the wash liquors.
EXAMPLE 8
Using the procedure described in Example 1, 2-methoxycamphene (18.9 g., 0.114 mole) was reacted with an excess of methylnitrite (25 g., 0.406 mole) in the presence of one mole percent of 20% oleum as catalyst. There was no indication of blue coloration (nitroso compounds) or a precipitate during the course of the reaction. After neutralization with sodium bicarbonate, the solvents were removed by flash evaporation yielding a pale yellow liquid (13.4 g). The yield is low due to analyses during the course of the run and also the possibility of volatilization during the evaporation of the solvents. IR and nmr indicate a mixture of products. The following components were identified by Finigan Mass Spec: ##STR13## There was no evidence for 2,2-dimethoxy-3-oximinocamphor or 2,2-dimethoxy-3-nitrosocamphor or its dimer.
EXAMPLE 9
Using the procedure described in Example 1, 2,2-bis-(4-methoxycyclohex-2-enyl)propane (5 g., 0.0378 mole) was reacted with an excess of methylnitrite (25 g., 0.406 mole) in the presence of one mole percent of ethyldimethoxycarbonium fluoroborate as catalyst. While the reaction mixture was blue-green in color, there was no precipitate formed. The reaction mixture was neutralized with sodium bicarbonate and the excess methylnitrite was distilled from the reactor and stored for later reactions. The solid product was dissolved in 50 ml dichloromethane and filtered to remove inorganics. The product (7.1 g. pale green solid) was recovered by flash evaporation of the solvent. The nmr spectrum is compatible with the nitroso dimer structure but the IR also indicates the presence of nitroso groups. This is probably indicative of difficulties encountered in working with systems that can polymerize since possibly all of the nitroso groups cannot dimerize due to steric factors.
EXAMPLE 10
Using the procedure described in Example 1, attempted preparation of the 7,7-dimethoxy-6-nitrosotridecane dimer was carried out by reacting 7-methoxytridec-7-ene (28 g., 0.132 mole) with an excess of methylnitrite (25 g., 0.406 mole) in the presence of one mole percent of ethyldimethoxycarbonium fluoroborate as catalyst. After neutralization of the catalyst with sodium bicarbonate, the excess methylnitrite was recovered by distillation. The reaction residue was dissolved in pentane (25 ml) and filtered to remove the inorganic material. On flashing off the pentane, a product (24.2 g.) was recovered which was not the dimer but mostly 7,7-dimethoxy-6-oximinotridecane. This structure was confirmed by nmr and IR. IR also indicates the presence of some carbonyl containing product which could be the methylester of octanoic acid. The yield of product is lower due to the removal of reaction mixture for analysis during the course of the reaction.
EXAMPLE 11
Using the procedure described in Example 10, a mixture (18.75 g., 0.135 mole) of 2-methoxyoct-2-ene (80%) and 2-methoxyoctene (20%) was reacted with an excess of methylnitrite (25 g., 0.406 mole) in the presence of one mole percent of ethyldimethoxycarbonium fluoroborate as catalyst. The product (23.3 g.) was a yellow liquid which, by nmr analysis, did not contain any dimer but was mostly a mixture of 3,3-dimethoxy-2-oximinooctane and 2,2-dimethoxy-1-oximinooctane. IR indicates the presence of an ester function which could mean that further reaction of the oximes may have taken place.
EXAMPLE 12
1,1-Dimethoxy-2-nitrosocyclohexane dimer (59.3 g.) as prepared in Examples 1 or 2 was dissolved in dichloromethane (200 ml) and allowed to stand at room temperature for three days. The tan solution was treated with decolorizing charcoal and filtered through a celite cake in an attempt to remove colored impurities. This was not successful. After flashing off the dichloromethane, the tan product (49.1 g.), m.p. 115°-116°, was essentially pure 1,1-dimethoxy-2-oximinocyclohexane by nmr and IR analysis.
EXAMPLE 13
Production of 1,1-dimethoxy-2-oximinocyclochexane
1,1-Dimethoxy-2-nitrosocyclohexane dimer (25.0 g., 72.2 mmole) prepared in Example 1 was suspended in 175 ml. of methanol and then made basic to pH 8 with sodium methoxide. The reaction mixture was stirred at 50° C. under a dry nitrogen atmosphere for 11/2 hours. After reducing the volume to 75-100 ml. on a rotary evaporator and slowly cooling to -20° C., the oxime was filtered off directly as clear colorless needles, 15.6 g., m.p. 116°117°. An additional crop of slightly impure crystals, 4.2 g., m.p. 108°115°, was collected by recrystallizing the residue from ether/pentane at -70° C. Total yield of oxime was 19.8 g. (79.2%).
EXAMPLE 14
1,1-Dimethoxy-2-nitrosocyclododecane dimer as prepared in Example 7, (31 g.) was heated (95° C.) in dry toluene (300 ml) for 1.5 hours with 150 mg. NaOCH 3 as catalyst. The suspended solid slowly dissolved in the blue-green reaction mixture which finally became yellow indicating that all of the nitroso groups had reacted. The cool reaction mixture was filtered through celite to remove inorganic material and the toluene was removed by flash evaporation. The cream colored solid (29.9 g.) was confirmed as 1,1-dimethoxy-2-oximinocyclododecane by nmr.
With more soluble nitroso dimers, such as 1,1-dimethoxy-2-nitrosocyclohexane, anhydrous methanol can be used as solvent in the above reaction. 1,1-Dimethoxy-2-nitrosocyclododecane was refluxed in methanol with catalytic quantities of sodium methoxide and was recovered unchanged. When n-butanol (b.p. 118° C.) was used as solvent, the conversion to the oxime took place within 0.5 hours. However, there was interchange of butoxy groups for methoxy groups in the oxime so the use of n-butanol as solvent was discontinued.
EXAMPLE 15
2,2-Bis(4-methoxy-3-nitrosocyclohexyl)propane dimer (1 g.) as prepared in Example 9, was heated in dry toluene (10 ml) in the presence of catalytic amount of sodium methoxide. The bluegreen solution turned yellow and a precipitate formed. The reaction mixture was refluxed for three hours. The light tan precipitate (0.57 g.) was reovered by filtration and IR indicates it is mainly 2,2-bis(4-methoxy-3-oximinocyclohexyl)propane. The filtrate was flash evaporated and the residue (0.2 g.) was similar to the starting nitroso dimer by nmr and IR analysis.
EXAMPLE 16
1,1-Dimethoxy-2-nitrosocyclooctane dimer (18.3 g.), prepared according to Example 6, was dissolved in dry toluene (150 ml.) at 45° C. and catalyzed with about 150 mg. of sodium methoxide. Within five minutes, the deep blue color changed to yellow and a reaction exotherm caused the temperature to rise to 56° C. The reaction mixture was stirred at ambient temperatures for 2.5 hours and the toluene flashed off after filtering off the inorganic materials using a celite cake. The pale yellow solid (15.3 g.) was identified as 1,1-dimethoxy-2-oximinocyclooctane by IR and nmr analysis. Some was lost during the filtration.
EXAMPLE 17
1,1-Dimethoxy-2-oximinocyclohexane was produced directly from 1-methoxycyclohexane and methyl nitrite using the following procedure:
1,1-Dimethoxy-2-nitrosocyclohexane dimer was prepared as described in Example 1 from 1-methoxycyclohexene (46.8 g., 0.417 mole), methyl nitrite (30.6 g., 0.501 mole) and boron trifluoride-etherate (0.25 ml., 0.28 g., 2.0×10 -3 mole) in 250 ml. of sulfur dioxide. The crude nitroso dimer, 76.0 g. of a gummy yellow-green solid still containing traces of sulfur dioxide, was obtained by the method described earlier. Without purification, the dimer was subjected to isomerizing conditions in methanol/sodium methoxide solution. Filtration through celite (to remove colloidal solids that had formed) and evaporation afforded 66.0 g. of an off-white slightly moist solid. Recrystallization from 180 ml. of ether at -70° C. gave 26.8 g. (37.2%) of 1,1-dimethoxy-2-oximinocyclohexane as colorless fine needles, m.p. 112°-116° C. An additional 2.9 g. (4.0%) of slightly impure oxime was obtained from the mother liquor as a white powder, m.p. 105°-112° C.
EXAMPLE 18
1,1-Diethoxy-2-oximinocyclohexane was produced directly from 1-ethoxycyclohexene and nitrosyl chloride using the following procedure.
1-Ethoxycyclohexene (6.3 g., 50 mmole) was added to 100 ml. SO 2 maintained at about -50° C. Then 4.4 ml. (75 mmole) ethanol were added after which 3.2 ml. (70 mmole) nitrosyl chloride was added as a gas. When addition of the nitrosyl chloride was completed, the reaction mixture was concentrated, chloroform was added and the solution neutralized, with sodium bicarbonate in the presence of a small amount of water. The product was filtered and the crystals analyzed by nmr to indicate the presence of a major proportion of the desired product.
EXAMPLE 19
The procedure of Example 18 was repeated using ethyl ether as a solvent in place of SO 2 . When the reaction was complete, the mixture was treated with additional ether, solid sodium bicarbonate and a small amount of water. The crystals collected after filtration and evaporation were examined by nmr and found to consist essentially of 1,1-diethoxy-2-oximinocyclohexane.
EXAMPLE 20-22
Methods similar to those employed in Examples 2 and 17-19 can be used to produce the following novel compounds.
______________________________________Ex-ample Ether Nitrosating Agent Product______________________________________20 1-methoxy-4-t- ethyl nitrite 1-methoxy-1- butylcyclohexene ethoxy-2-oximino- 4-t-butylcyclo- hexane21 1-methoxy-5- NOCl + 4- 1-methoxy-5- phenylcyclo- methylcyclo- phenyl-1-(4'- hexene hexanol methylcyclo- hexyloxy)2- oximinocyclo- hexane22 3-methoxy methyl 3,3-dimethoxy- cholestene-2 nitrite 2-oximinocholes- tane______________________________________
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This invention describes novel ketals of α-oximinoketones, methods for the preparation of these compounds and includes novel intermediates formed during the production thereof. The novel class of compounds disclosed herein includes both α-oximinoketals, as well as the cyclic ketals of α-oximinoketones. This invention also discloses a novel class of α-nitrosoketal dimers produced during the synthesis of the corresponding α-oximinoketals, and it also discloses novel methods in the production thereof.
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BACKGROUND OF THE INVENTION
FIELD OF THE INVENTION
[0001] The present invention relates to a machine for processing sheets, having a delivery for delivering the sheets that includes a delivery drum that is acted on pneumatically.
[0002] In German Patent DE 1 561 043 corresponding to U.S. Pat. No. 3,542,358 to Schuhmann, such a machine, whose delivery drum is acted on with blown air, is described. By the application of positive pressure to the delivery drum, a thin air cushion is formed between the sheet and the drum periphery, which prevents the printing ink from the sheet being smeared onto the drum. However, the application of positive pressure does not manage to prevent the printing ink smearing from the sheet transported by the delivery drum to the machine parts adjacent to the delivery drum.
SUMMARY OF THE INVENTION
[0003] It is accordingly an object of the invention to provide a machine for processing sheets that overcomes the hereinafore-mentioned disadvantages of the heretofore-known devices of this general type and that has a delivery drum the transports the sheets safely past the adjacent machine parts without smearing.
[0004] With the foregoing and other objects in view, there is provided, in accordance with the invention, a machine for processing sheets, having a delivery, or deliverer, for delivering the sheets includes a delivery drum that is acted on pneumatically, is characterized by acting on the delivery drum with a vacuum.
[0005] As a result of acting on the delivery drum with a vacuum, in the machine according to the invention, a route for solving the problem—which is completely opposite to the prior art (e.g., German Patent DE 1 561 043)—is followed. It has been found that, for the protection against smearing onto the adjacent machine parts, it is much more effective to keep the sheet in contact with the delivery drum for some time by a vacuum of the latter, instead of keeping the sheet at a distance from the delivery drum by a blown air cushion.
[0006] Advantageous developments will be explained briefly in detail in the following text.
[0007] In an advantageous development with regard to protecting the sheets against smearing of their printed image as a result of the contact between the sheet and delivery drum necessitated by the application of vacuum, in accordance with another feature of the invention, the delivery drum includes disks for carrying the sheets. Because of the narrowness of the disks, these carrying disks support the sheet only locally, as seen over its sheet width, and not over the entire sheet width. As viewed in the direction of the sheet width, the disks can be disposed after one another such that contact points determined by the disks are located within corridors that are free of a printed image and that run in the longitudinal direction of the respective sheet. What is important to the disks is primarily their narrowness and less whether the respective disk is circular, corresponding to a full circle or, instead, only has the shape of a circular segment, or whether the respective disk is produced from one piece or is assembled from a plurality of segments. As a result of the interaction between the application of vacuum and the disks of the delivery drum, the sheet is held exactly and in a stable position on its necessary transport path, and the printing ink from the sheet can smear neither onto the delivery drum nor onto the machine parts adjacent to the delivery drum. The delivery drum is, therefore, particularly well suited to transporting sheets printed on both sides.
[0008] In accordance with a further feature of the invention, each of the disks includes vacuum channels for holding the sheets. Although it is also conceivable to act on a drum part adjacent to the respective disk with the vacuum holding the sheet on the delivery drum, the application of vacuum to the disks themselves, carried out by the vacuum channels, is more advantageous from a functional and constructional point of view. The vacuum channels can have openings in the peripheral surface of the respective disk, and these openings can form a row running in the peripheral direction of the disk.
[0009] In a departure from this development, however, it is also conceivable to provide only a single vacuum channel for each disk and a vacuum groove that extends in the peripheral direction of the disk, in its peripheral surface, which is open toward the sheet and in the base of which the vacuum channel opens.
[0010] In a development that is advantageous with regard to avoiding drawing extraneous air into the delivery drum, in accordance with an added feature of the invention, the openings of the vacuum channels and a vacuum connection together form a rotary valve for the cyclic application of vacuum to the vacuum channels. The rotary valve ensures that each of the vacuum channels is connected at least once to the vacuum in the course of a complete revolution of the disk and is, then, isolated from the vacuum again. Although it is, likewise, conceivable for a common rotary valve to be associated with the disks (whose number is at least two and, preferably, exactly two), the valve controlling the vacuum in the vacuum channels of all the disks cyclically, it can be advantageous from various points of view to assign a different, dedicated rotary valve to each of the disks so that the rotary valves work with one another in parallel operation.
[0011] In accordance with an additional feature of the invention, a vacuum-active angular range of the delivery drum is determined by the rotary valve or by each rotary valve, and is located in an exit pocket of a drum-cylinder nip. The rotary valve, therefore, ensures that the suction action from the delivery drum or its disks is exerted in a targeted manner in the exit pocket on the sheet section that has already emerged from the drum-cylinder nip and not on the sheet section that has not yet entered the drum-cylinder nip. In the region of an inlet pocket of the drum-cylinder nip, opposite the exit pocket, the vacuum channels are kept vacuum-inactive by the rotary valve so that the vacuum channels attract the sheet by suction at the earliest in the drum-cylinder nip in the course of its rotation.
[0012] In accordance with yet a further feature of the invention, a sheet guide device that is adjacent to the delivery drum extends into the vacuum-active angular range. Such a sheet guide device is a machine element that is immediately adjacent to the delivery drum and that is intended to be protected against smearing by the application of vacuum to the delivery drum. The rotary valve or each rotary valve activates the vacuum of the delivery drum in the cycle of the sheets conveyed through between the delivery drum and the sheet guide device. The sheet guide device is, preferably, a pneumatically acting sheet guide device that is equipped with air nozzles, preferably, with blown air nozzles assisting the vacuum of the delivery drum from the opposite side. For example, the sheet guide device can be formed as a blown air box or as a blower pipe configuration.
[0013] In a development that is advantageous with regard to pneumatic stabilization of the sheet position of one and the same sheet carried out simultaneously before and after the drum-cylinder nip, in accordance with yet another feature of the invention, the drum-cylinder nip is formed by the delivery drum together with an impression cylinder, and a blowing device for blowing the sheets against the impression cylinder is allocated to the impression cylinder. The blown air from the blowing device is aimed at the sheet and presses the sheet firmly against the peripheral surface of the impression cylinder. The vacuum-active angular range of the delivery drum and the blowing device are disposed to be offset from each other along the sheet transport path such that the blowing device holds the rear half of the sheet still on the impression cylinder while the front half of the sheet is already being held by the activated vacuum channels on the delivery drum.
[0014] In accordance with yet an added feature of the invention, the blowing device is allocated to the impression cylinder between a press nip formed by the impression cylinder and the drum-cylinder nip. As viewed in the direction of movement of the sheets, the blowing device is, therefore, disposed after the press nip and before the drum-cylinder nip. The impression cylinder can form the press nip together with a blanket cylinder provided for offset printing or instead for full-surface varnishing or with a printing form cylinder bearing a flexographic printing form for spot varnishing.
[0015] In accordance with yet an additional feature of the invention, at least one of the disks is mounted such that it can be adjusted relative to another of the disks in the direction of the width of the sheets, that is to say, transversely with respect to the transport direction of the sheets. The disk is, preferably, mounted such that it can be set as desired to various distances relative to the other disk. This setting can, preferably, be carried out continuously so that, within the adjustment range of the disk, any desired distance between the adjustable disk and the other disk can be set. The respectively selected distance, at which the disk is secured after its setting, can depend on the format of the sheets (sheet width) or on the position of the already mentioned corridors of the sheet that are free of a printed image.
[0016] In accordance with again another feature of the invention, the delivery drum is disposed or mounted within a circulation path of a chain conveyor. This means that the delivery drum is disposed such that chains of the chain conveyor run around the delivery drum.
[0017] In accordance with again a further feature of the invention, the machine according to the invention is, preferably, configured as a perfecting press. In such a perfecting press, each sheet is printed on both its sides in a single printing cycle. In connection with such sheets printed on both sides, the envisaged anti-smearing measures (vacuum application, disks) come fully into effect. As a result of the vacuum application, smearing of the printed image on the sheet side facing away from the delivery drum is avoided, by its contact with the sheet guide device being avoided and, by the disks, at the same time smearing of the other printed image on the sheet side facing the delivery drum is avoided by the facing sheet side being supported by the disks only in unprinted regions, that is to say, outside the printed image.
[0018] With the objects of the invention in view, there is also provided a machine for processing sheets, including a delivery for delivering the sheets, the delivery having a delivery drum with a surface and a vacuum source fluidically connected to the delivery drum and applying a negative pressure vacuum to the delivery drum to draw air from the surface of the delivery drum.
[0019] With the objects of the invention in view, there is also provided a machine for processing sheets, including a delivery for delivering the sheets, the delivery having a delivery drum acted on pneumatically by having a vacuum applied thereto, disks for carrying the sheets, each of the disks defining vacuum channels for holding the sheets, and the vacuum channels having openings and a vacuum connection, the openings and the vacuum connection together forming a rotary valve cyclically applying the vacuum to the vacuum channels.
[0020] Other features that are considered as characteristic for the invention are set forth in the appended claims.
[0021] Although the invention is illustrated and described herein as embodied in a machine for processing sheets, 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.
[0022] 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
[0023] FIG. 1 is a cross-sectional view of an overall diagrammatic illustration of a press having a sheet delivery according to the invention;
[0024] FIG. 2 is a fragmentary, cross-sectional view of a delivery drum of the sheet delivery of FIG. 1 ; and
[0025] FIG. 3 is a fragmentary, perspective view of the delivery drum of FIG. 2 .
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0026] Referring now to the figures of the drawings in detail and first, particularly to FIG. 1 thereof, there is shown a machine 2 processing sheets 1 . The machine 2 is a sheet-fed press, specifically a recto and verso press, and includes a printing unit 3 . 1 for printing the front side of the sheet and a printing unit 3 . 2 for printing the rear side of the sheet. The printing unit 3 . 2 includes an impression cylinder 4 and a blanket cylinder 27 , these two cylinders 4 and 27 together forming a press nip 24 . In addition, the machine 2 includes a delivery 5 having a chain conveyor 6 and what is referred to as a delivery drum 7 . The chain conveyor 6 runs around the delivery drum 7 and deposits the sheets 1 on a stack 8 . The chain conveyor has grippers 9 , which move along a circulation path 26 , and chains 10 that carry the grippers 9 and determine the circulation path 26 . The impression cylinder 4 transfers the sheets 1 one after another to the grippers 9 at a transfer point. The transfer point is a drum-cylinder nip 23 formed by the delivery drum 7 together with the impression cylinder 4 and is located in the first quadrant of the delivery drum 7 if a sheet transport direction from right to left is used as a basis, as in FIG. 1 .
[0027] The delivery drum 7 is what is referred to as a skeleton drum and has disks 11 that carry the sheets 1 and are seated at a distance from one another on a rotating axle 25 . Each of the two disks 11 is mounted such that it can be displaced individually and relative to the other of the two disks 11 along the axle 25 . As a result of the displacement of the two disks 11 , these can be adjusted closer together or further apart as desired, and each of the two disks 11 can be positioned in a manner coordinated with the sheet format of the respective print job such that the disks 11 contact the sheets 1 only at their side edges free of a printed image. Used as the axle 25 is what is referred to as the sprocket shaft, on which there are seated sprockets 12 that engage in the chain teeth and belong to the chain conveyor 6 . The disks 11 have diametrical clearances 13 , into which the grippers 9 , formed as gripper bars, dip during their circulation. The peripheral speeds of the chain conveyor 6 and of the delivery drum 7 or the disks 11 are synchronized. In addition, each disk 11 is associated with a securing device 14 , by which the corresponding disk 11 can be fixed on the axle 12 in its respective axial position suitable for the format, for example, can be clamped firmly. The external diameter of the disks 11 substantially corresponds to that of the sprockets 12 and of the impression cylinder 4 .
[0028] The delivery drum 7 , which is acted on pneumatically internally, is what is referred to as a vacuum drum and has vacuum channels 15 that are introduced into the disks 11 . The vacuum channels 15 extend longitudinally substantially radially and open in the peripheral surface of the respective disk 11 . Openings 16 of the vacuum channels 15 are disposed in rows, which run in the peripheral direction of the delivery drum 7 and extend substantially over the entire sheet length of the maximum sheet format. Each of the vacuum channels 15 is formed from a radial bore and a transverse bore that extends parallel to the axle 25 and intersects the radial bore. The transverse bores forming the inner ends of the vacuum channels 15 each have an opening 17 .
[0029] These openings 17 of the vacuum channels 15 cooperate periodically in the course of the rotation of the respective disk 11 with a stationary vacuum connection 18 , which does not co-rotate with the disk 11 . The vacuum connection 18 is a groove in the shape of a circular arc and is permanently under a negative pressure that is produced by a vacuum source 30 (only illustrated diagrammatically in FIG. 2 ), which is connected to the vacuum connection 18 . The vacuum connection 18 is open toward the openings 17 that, in the course of the rotation of the disks 10 about the geometric axis of rotation of the axle 12 , overlap one after another with the vacuum connection 18 to which vacuum is applied conducting vacuum from the vacuum channels 15 into the vacuum connection 18 . Each of the curved rows formed by the openings 17 , as viewed in the peripheral direction, is longer than the curved length of the vacuum connection 18 so that always only a subset of the vacuum channels 15 of the respective row and never all the vacuum channels 15 of this row communicates simultaneously with the vacuum connection 18 . The vacuum channels 15 , together with the vacuum connection 18 , therefore, form a rotary valve 19 , which is placed such that the delivery drum 7 is pneumatically active with respect to the outside only within an angular range a that begins substantially only at the transfer point 10 and ends still in the fourth quadrant of the delivery drum 7 . The angular range a is located in the immediate vicinity of an exit pocket 22 from the drum-cylinder nip 23 . Because of the alignment of the rotary valve 19 , the openings 16 are active in applying vacuum to the sheets 1 only within the angular range a. Within the angular range a, it is particularly important that the sheet 1 transported to the chain conveyor 6 is attracted against the delivery drum 7 by suction by the openings 16 to which vacuum is applied and is kept in contact with the rotating disks 10 and at a distance from a sheet guide device 20 , which extends with its curved end section as far as the angular range a underneath the delivery drum 7 .
[0030] The sheet guide device 20 , running in a curve partly around the delivery drum 7 , includes a guide plate provided with blower nozzles. A blowing device 21 aimed with its blown air jets at the impression cylinder 4 , substantially in the second quadrant of the impression cylinder 4 , is used to hold the sheet 1 on the impression cylinder 4 .
[0031] FIG. 2 illustrates a transport phase of the sheet 1 that is particularly critical in regard to the smearing of the ink printed in the printing unit 3 . 1 from the sheet 1 to the sheet guide device 20 . In this transport phase, the leading sheet end is gripped by a gripper 9 passing the delivery drum 7 and the trailing sheet end has already emerged from the press nip 24 (cf. FIG. 1 ) of the printing unit 3 . 2 .
[0032] Without any suitable countermeasure, there would be a risk of the sheet 1 separating from the delivery drum 7 in the angular range α and forming a loop of printing material that, as a result of striking the sheet guide device 20 , could cause smearing.
[0033] A countermeasure that prevents this and has been tested successfully by the applicant functions as set forth in the following text.
[0034] The vacuum channels 15 , which act after the transfer point (drum-cylinder nip 23 ), and the blowing device 21 disposed before this transfer point act together such that the sheet 1 exactly maintains its substantially S-shaped longitudinal curvature following the peripheral lines of the impression cylinder 4 and of the delivery drum 7 during the critical transport phase and, thus, the disastrous formation of waves in the printing material of the sheet 1 is suppressed. In tests, it has been shown that the action of the blowing device 21 on its own is not completely adequate to force the sheet 1 into its requisite movement path and to keep it at a distance from the sheet guide device 20 within the angular range a.
[0035] However, it is not ruled out that, in specific applications, by its vacuum, the delivery drum 7 is sufficiently effective on its own, that is to say, without any support by the blowing device 21 .
[0036] Nonetheless, the combination of the pneumatic devices disposed on the two opposite sides of the transfer point (upstream blowing device 21 , downstream angular range a of the vacuum delivery drum 7 ) has proven to be particularly effective.
[0037] This application claims the priority, under 35 U.S.C. § 119, of German patent application No. 103 32 217.5, filed Jul. 16, 2003; the entire disclosure of the prior application is herewith incorporated by reference.
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The invention relates to a machine for processing sheets, having a deliverer for delivering the sheets which comprises a delivery drum that is acted on pneumatically. The delivery drum has vacuum applied to it. The delivery drum also has disks for carrying the sheets, each of the disks defining vacuum channels for holding the sheets. The vacuum channels have openings and a vacuum connection. The openings and the vacuum connection together form a rotary valve cyclically applying vacuum to the vacuum channels.
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CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims the priority benefit of United Kingdom Patent Application No. GB0616555.9, titled “Apparatus and Method”, filed Aug. 19, 2006.
BACKGROUND
[0002] The present invention relates to an apparatus and a method for selectively controlling fluid flow. In particular, the invention relates to an apparatus and method for use in downhole operations in the hydrocarbon production industry. The invention also relates to a progressive cavity pump comprising a fluid flow control apparatus.
[0003] During extraction of resources from beneath the surface of the earth and especially in the oil and gas exploration and production industry, it is often necessary to overcome a pressure differential (hydrostatic head) between a subterranean fluid reservoir and the surface. This can be achieved using a pump such as a progressive cavity pump (hereinafter a “PCP”).
[0004] FIG. 1 is a cut away side view of part of a typical prior art PCP 12 . PCPs 12 typically comprise a helical steel rotor 16 and a rubber stator 14 having a double screw profile matching the helical rotor 16 . The stator 14 is formed to allow rotation of the inserted rotator 16 therein and this arrangement results in a series of cavities 18 along the length of the PCP 12 between the rotor 16 and the stator 14 . The stator 14 is usually encapsulated within a tubing section (not shown) that typically forms part of a tubing string running from the reservoir to the surface. The rotor 16 is typically connected to a rod string (not shown) having a smaller diameter than the tubing string where the rod string is admitted within the throughbore of the tubing string and positioned such that the rotor 16 is located within the stator 14 . The rod string is then connected to a rotary motor at the surface to power rotation of the rod string and attached rotor 16 at the appropriate speed.
[0005] When the PCP 12 is in use, rotation of the rotor 16 within the stator 14 creates a positive displacement that causes fluids in the cavities 18 to progress upwards due to a gradual build-up of pressure from the inlet to the discharge of the PCP 12 . The build-up of pressure causes positive displacement of fluid within the cavities 18 and provides the necessary lift to extract fluid from the reservoir and pump it towards the surface thereby overcoming the hydrostatic head.
[0006] PCPs 12 are often used in wells that produce high quantities of sand along with the produced fluids due to the material selection of the pump 12 and use of the rubber stator 14 against the steel rotor 16 , PCPs 12 are also suitable for production of heavy hydrocarbons and are commonly used in wells for extraction of high viscosity fluids. An important factor in determining the lifetime of the PCPs 12 is the quantity of sand and solids present in the hydrocarbon and fluid mixture passing through the pump 12 .
[0007] Stopping operation of the PCP 12 can result in the sand (that is entrained in fluids within the production tubing above the PCP 12 having already been pumped) settling above the stator 14 and creating a sand plug in the tubing string. Once the PCP 12 is restarted, the rotor 16 may run dry within the stator 14 for a period of time until the requisite pressure accumulates to blast away the sand plug. During this period, the PCP 12 rotor 16 running dry within the stator 14 can tear up or otherwise cause severe damage to the stator 14 resulting in destruction of the pump 12 . The PCP system would then require replacement with the associated high cost due to lengthy down time and loss of well production. Conventionally, this situation is avoided by dissipating the sand plug using a rig to pull the rod string and attached rotor 16 out of the stator 14 . Sand can then fall through the stator 14 and out of the lower end of the pump 12 after which the rod string and attached rotor 16 can be repositioned within the stator 14 . However, this operation is both costly and time consuming and results in undesirable downtime.
[0008] Since the PCP 12 is a positive displacement pump, there is no method for allowing fluids to free flow through the pump 12 from the reservoir to the surface in the event of pump 12 failure. Additionally, there is no method by which fluids from the surface can be forced into the reservoir through the pump 12 to conduct reservoir treatments. These operations are conventionally conducted by pulling the rod string and attached rotor 16 from the wellbore and allowing fluids to free flow through the stator 14 . Again, this is a costly and time consuming operation and results in undesirable downtime.
SUMMARY
[0009] According to a first aspect of the present invention, there is provided an apparatus for selectively controlling fluid flow. The apparatus includes a body member having a throughbore formed therein, at least one bypass port formed in the body member, a rotatable member arranged for insertion and rotation within the throughbore of the body member thereby creating first and second annular portions, and a moveable member. The moveable member is moveable between a first configuration which defines a first fluid flow path between the first and second annular portions and a second configuration which defines a second fluid flow path between the first annular portion and each bypass port.
[0010] Typically, the moveable member is moveable between the first and second configurations in response to fluid flow along one of the fluid flow paths, preferably the first fluid flow path.
[0011] Preferably, the apparatus is downhole apparatus for controlling the flow of naturally produced fluids, injected fluids or pumped produced fluids.
[0012] According to the first aspect of the present invention, there is provided a method of controlling fluid flow. The method includes providing a body member having a bypass port and a throughbore, inserting a rotatable member within the throughbore of the body member and thereby providing a first fluid flow path between a first annular portion and a second annular portion between the body member and the rotatable member and a second fluid flow path between the first annular portion and the bypass port in the body member, and providing a moveable member that is moveable between a first configuration in which flow is directed along the first flow path and a second configuration in which flow is directed along the second flow path. The moveable member moves between the first and second configurations in response to fluid flow along the first fluid flow path.
[0013] Typically, fluid flow along the first fluid flow path is provided by a pump. Preferably, sufficient fluid flow along the first fluid flow path moves and maintains the moveable member in the first configuration and insufficient or no fluid flow along the first fluid flow path results in movement of the moveable member to, and maintenance in, the second configuration. When the moveable member is in the second configuration, fluid flow is directed along the second fluid flow path, where the fluid flow is driven typically as a result of relatively high reservoir pressures.
[0014] Preferably, the method is directed to controlling the flow of naturally produced fluids, injected fluids or pumped produced fluids downhole.
[0015] Preferably, the method of controlling flow of fluid comprises diverting flow of fluid between the first and second flow paths and preferably comprises permitting the moveable member to move in response to fluid flow conditions within a downhole wellbore.
[0016] Typically, the moveable member is moveable in response to a pressure differential within the throughbore. The moveable member can be moveable in response to a pressure differential between the first and second annular portions.
[0017] The movable member can be biased towards the second configuration. The movable member can be biased by a resilient means towards the second configuration.
[0018] Biasing the moveable member in the second configuration allows fluid in the throughbore above the apparatus to circumvent the second annular portion, should the pressure differential between the first and second annular portions be insufficient to overcome the biasing force of the resilient means.
[0019] The moveable member can translate between the first and the second configuration by movement in a direction substantially parallel to a longitudinal axis of the body member. The movable member can comprise a cylindrical sleeve coupled to an inner surface of the body member and movable relative thereto.
[0020] The moveable member can be arranged in the first configuration to permit fluid flow in the first fluid flow path and prevent fluid flow in the second fluid flow path. The moveable member can be adapted to open the bypass port(s) when in the second configuration and to obturate the bypass port(s) when in the first configuration. The moveable member can comprise a sleeve having one or more openings provided in the sidewall. The openings can be aligned with the bypass port(s) in the second configuration and the sidewall of the sleeve can obturate the bypass port(s) in the first configuration.
[0021] The moveable member can, in the second configuration, be adapted to permit fluid flow in the second fluid flow path and prevent fluid flow in the first fluid flow path. The moveable member can be adapted to close the annulus between the first and second annular portions when in the second configuration and can be adapted to permit fluid flow in the annulus between the first and second annular portions when in the first configuration.
[0022] The movable member can comprise a protrusion extending radially into the annulus. The rotatable member can comprise an enlarged portion such that translation of the moveable member into the second configuration comprises movement of the radial protrusion of the moveable member into contact with the enlarged portion of the rotatable member to substantially close the annulus therebetween. Preferably, the radial protrusion of the moveable member only permits flow of fluid through the second annular portion when the bypass port(s) is/are substantially obturated by the sidewall of the moveable member. Preferably the radial protrusion is arranged such that fluid flow can act on a face of the radial protrusion to maintain the movable member in the first configuration when the fluid exerts a force on the face that is above a predetermined force.
[0023] Preferably, the moveable member and the rotatable member are coupled to a pump such as a PCP. Preferably, the moveable member translates from the second configuration to the first configuration when the pump is activated and remains in the first configuration whilst the pump means remains in operation. The moveable member can be actuated to move from the first configuration to the second configuration when the pump is deactivated and can remain in the second configuration whilst the pump remains deactivated.
[0024] The rotatable member can be coupled at one end to a rotor for use in a progressive cavity pump. The other end of the rotatable member can be coupled to a motor for driving rotation of the rotatable member. An end of the body member can be coupled to tubing having a stator disposed therein.
[0025] Embodiments of the present invention have the advantage that the PCP pump does not have to blast away a solids or sand plug in the production tubing above the apparatus on reactivation. This is because no sand plug is created, since when the PCP is inactive, the moveable member can occupy the second configuration and the second fluid flow path is open allowing solids to settle outwith the tubing in which the rotor/stator of the PCP are located.
[0026] The method can include latching the rotatable member in a predetermined position relative to the body member.
[0027] The apparatus can further be provided with a latch device for correctly positioning between the rotatable member relative to the body member. The latch device can ensure the correct position of the enlarged portion relative to the radial protrusion and/or of the rotor relative to the stator. The latch device can comprise corresponding engagement portions provided on the body member and the rotatable member. The engagement portions can comprise intermitting splines. The rotatable member can be rotatable relative to the engagement portion provided on the rotatable member.
[0028] The engagement portion of the rotatable member can be provided on the enlarged portion. An inner surface of the body member can be provided with a fastener formed with corresponding engagement portions and having a throughbore for accommodating the rotatable member therebetween.
[0029] The rotatable member can also be provided with a driver for driving the engagement portions of the rotatable member and the body member into secure engagement with one another. The driver can comprise a rigid band attached to the rotatable member that is capable of contacting and driving the engagement portions into secure engagement. The driver can also be utilised to provide an indicator means for positioning the rotor correctly into the stator.
[0030] Preferably, the apparatus comprises a first sealing means that is adapted to seal the bypass port(s) from the first annular portion when the moveable member is in the first configuration. The apparatus can comprise a second sealing means that is adapted to seal the annulus between the first and second annular portions when the moveable member is in the second configuration.
[0031] The sealing means can comprise annular seals or annular sliding seals. The first sealing means can comprise at least one annular seal provided on each side of the bypass port(s) on an inner surface of the body member to seal against a surface of the moveable member. The second sliding seal can comprise an annular sealing means provided on an outer surface of the radial protrusion.
[0032] Alternatively, at least one of the first or second sealing means can comprise a pressure locked sleeve, such as those described in United Kingdom Patent No. GB2411416B, the full disclosure of which is incorporated herein by reference.
[0033] When in the second configuration, preferably, the bypass port(s) formed in the body member are adapted to encourage solids present in fluids downstream of the moveable member to settle out with the body member rather than the solids falling through the first and second annular portions to settle within the body member.
[0034] According to a second aspect of the invention, there is provided a body member for use with a rotatable member, wherein the body member has a throughbore for receiving a rotatable member and at least one bypass port formed through a sidewall of the body member; and wherein the body member is further provided with a moveable member that is moveable between a first configuration in which the bypass port(s) are substantially obturated and a second configuration in which the bypass port(s) are in fluid communication with the throughbore.
[0035] The moveable member can be coaxial with the body member and sealed thereagainst. The body member can be coupled to tubing having a stator for use in a PCP formed therein.
[0036] According to the second aspect of the invention, there is also provided a rotatable member for insertion into a body member, wherein the rotatable member comprises an enlarged portion releasably coupled thereto, which enlarged portion is arranged for engagement with a part of the body member to thereby attach the rotatable member to the body member such that the rotatable member is rotatable relative to the body member.
[0037] The rotatable member can also be provided with a driver attached thereto, as described with reference to the first aspect of the invention. The rotatable member can be coupled to a rotor for use in a PCP.
[0038] According to a third aspect of the invention, there is provided a progressive cavity pump comprising a fluid flow control apparatus for selectively controlling fluid flow through the progressive cavity pump and selectively diverting fluid flow around the progressive cavity pump.
[0039] The body member, rotatable member and fluid flow control apparatus of the second and third aspects of the invention can comprise any features of the apparatus described with reference to the first aspect of the invention, where applicable.
DESCRIPTION OF THE DRAWINGS
[0040] Embodiments of the present invention will now described by way of example only and with reference to the accompanying figures in which:
[0041] FIG. 1 is a side view of a part of a progressive cavity pump;
[0042] FIG. 2 is a sectional view of a body member of an apparatus according to a first aspect of the present invention;
[0043] FIG. 3 is a sectional view of the apparatus of FIG. 2 having a rotatable member disposed therein in a second configuration;
[0044] FIG. 4 is a sectional view of the apparatus of FIG. 3 in a first configuration; and
[0045] FIGS. 5-10 are perspective views of the apparatus of FIGS. 3 and 4 with a portion of the moveable member cut away and showing consecutive steps of the assembly and operation of the apparatus.
DESCRIPTION
[0046] A body member of the apparatus according to the invention is shown generally at 11 in FIG. 2 . The body member 11 is substantially cylindrical and has a throughbore 13 . The body member comprises a lower sub 20 , a middle sub 40 and an upper sub 60 .
[0047] A lower end 20 L of the lower sub 20 is arranged to be coupled to production tubing (not shown) via a conventional screw threaded pin connection. The production tubing attached to the lower sub 20 typically extends to a hydrocarbon reservoir. A part of this production tubing is provided with the rubber stator 14 of the PCP 12 attached to an inner surface thereof. An upper end 60 U of the upper sub 60 is also adapted to be connected to production tubing via a conventional screw threaded box connection such that hydrocarbons can be produced from the reservoir through the progressive cavity pump 12 , the production tubing, the body member 11 and further production tubing up to the surface.
[0048] A substantially cylindrical latching device 22 is provided on the inner surface towards the upper end 20 U of the bottom sub 20 where the latching device 22 is coupled to the sub 20 by means of three attachment points 22 a (one of which is shown in FIG. 2 ) that project radially into the throughbore 13 from the inner surface of the lower sub 20 . The latching device 22 has splines 23 provided at its upper end and a centrally disposed passageway to accommodate a rotatable member.
[0049] The upper end 20 U of the lower sub 20 has a screw threaded pin connection that is arranged for insertion into a screw threaded box connection at a lower end 40 L of the middle sub 40 . At this connection point 30 , the throughbore 13 is fluidly isolated from the exterior of the body member 11 by an annular seal 24 recessed into an outer surface of the pin connection at the upper end 20 U of the lower sub 20 .
[0050] The middle sub 40 is substantially cylindrical having box connections at its upper and lower ends 40 U, 40 L. An inner surface of the middle sub 40 is provided with an annular step 46 in a substantially centrally disposed location. Towards the upper end 40 U, the middle sub 40 also has a plurality of downwardly extending bypass ports 42 formed through a sidewall thereof. The inner surface of the middle sub 40 adjacent the bypass ports 42 has recessed annular seals 44 , 45 on either side thereof. The box connection at the upper end 40 U engages with a pin connection at a lower end 60 L of the upper sub 60 . The ends 40 U, 601 of the middle and upper subs 40 , 60 are connected by a screw thread 50 and an outer surface of the lower end 60 L is provided with an annular seal 64 to fluidly isolate the exterior of the body member 11 from the throughbore 13 .
[0051] A moveable member 80 is coaxially located within the body member 11 . The moveable member 80 is substantially cylindrical and sealed against the inner surface of the body member 11 and is moveable in a direction parallel to a longitudinal axis of the body member 11 . A lower end 80 L of the moveable member 80 has an end face 80 e that is shown in FIG. 2 in its second configuration abutting an end face of the lower sub 20 . An inner surface of the moveable member 80 at its lower end 80 L has a radial protrusion 84 that projects radially inwardly into the throughbore 13 of the body member 11 . An outer surface of the moveable member 80 adjacent the radial protrusion 84 has an annular step 86 . Openings 82 are provided through a sidewall towards an upper end 80 U of the moveable member 80 .
[0052] Movement of the movable member 80 is limited at its lower end by the end face 20 e of the lower sub 20 and at an upper end by the annular step 46 of the middle sub 40 abutting the annular step 86 of the movable member 80 . A spring 88 is retained in the chamber defined between the annular step 46 , the annular step 86 , the outer surface of the movable member 80 and the inner surface of the middle sub 40 . The spring 88 biases the moveable member 80 into the configuration shown in FIG. 2 such that the end 80 e of the movable member 80 abuts against the upper end face 20 e of the bottom sub 20 .
[0053] A rotatable member in the form of a rod string 100 is shown in FIGS. 3 and 4 . The rod string 100 is provided with a conventional steel rotor 16 at its lowermost end and can be rotated from surface as will be subsequently described. The presence of the rotatable member within the body member 11 forms an apparatus 10 . Both the rod string 100 and the rotor 16 have an outer diameter less than the central passageway of the latching device 22 and are adapted to fit therethrough. The rod string 100 has a collar 102 arranged therearound. The collar 102 has a splined end 103 for engaging with the splines 23 provided on the latching device 22 . The collar 102 also has an inner bearing surface 102 b that allows rotation of the rod string 100 therethrough when the collar 102 is in its latched position engaged with the splines 23 of the latching device 22 . A lower end 100 L of the rod string 100 is coupled to the steel rotor 16 for insertion into the rubber stator 14 within the production tubing to thereby form the progressive cavity pump 12 . An upper end 100 U of the rod string 100 is coupled to a drive motor for driving rotation of the rod string 100 . The presence of the rod string 100 within the throughbore 13 creates a first annular portion 110 that is an annular space between a part of the rod string 100 and the inner surface of the body member 11 . A second annular portion 120 is also created between another part of the rotatable member 100 and the inner surface of the body member 11 . FIG. 3 shows the apparatus 10 in its second configuration wherein the first annular portion 110 is in fluid communication with the bypass ports 42 in the middle sub 40 , since the openings 82 of the movable member 80 are aligned therewith and the first annular portion 110 is obturated from the second annular portion 120 by the seal between the radial protrusion 84 and collar 102 . FIG. 4 shows the apparatus 10 in a first configuration wherein the first annular portion 110 is in fluid communication with the second annular portion 120 and the bypass ports 42 are obturated by a sidewall of the moveable member 80 .
[0054] Before use of the apparatus 10 , a lower end of the production tubing carrying the rubber stator 14 is positioned within a wellbore, with the body member 11 included in the tubing string downstream (vertically above) of the stator 14 . The upper end of the body member 11 is attached to production tubing that leads to surface as shown in FIG. 5 .
[0055] A rod string 100 commencing with the rotor 16 is fed through the body member 11 and the passageway in the latching device 22 until the collar 102 is located within the body member 11 (illustrated in FIG. 6 ). The splined portion 103 of the collar 102 latches with the splines 23 on the latch member 22 as shown in FIG. 7 . The rod string 100 continues to be fed through the collar 102 until the hammer 104 contacts an upper end of the collar 102 to compression fit the latch device 22 and the collar 102 into secure engagement by driving the interfitting splines 23 , 103 together ( FIG. 8 ). The rod string 100 can then be backed off such that the hammer 104 is moved away from the collar 102 as shown in FIG. 9 . The total length of the rod string 100 below the collar 102 is calculated such that the rotor 16 is correctly positioned within the stator 14 . The spring 88 ensures that the default position of the apparatus 10 is in a second or closed configuration to allow flow from the second annular portion 110 through the opening 82 in the sidewall of the moveable member 80 and the bypass ports 42 in the sidewall of the middle sub 40 .
[0056] Fluids and hydrocarbons can be produced naturally from the reservoir, (through the second fluid flow path) if the well pressure is sufficient to overcome the hydrostatic head following installation of the PCP 12 and apparatus 10 . Since the moveable member 80 is biased into the second configuration, the rod string 100 can be held against rotation so that the PCP 12 is inactive and fluids can be produced from the reservoir, through the bypass ports 42 , the openings 82 and the first annular portion 110 . Thus, the apparatus 10 provides a fluid flow path that circumvents the pump 12 , when the moveable member 80 is in the second or closed configuration.
[0057] When it is required to provide fluid such as hydrocarbons from the wellbore with artificial lift (for example, when the natural well pressure drops), the progressive cavity pump 12 is activated by driving rotation of the rod string 100 from the surface. This causes the rotor 16 to turn within the stator 14 thereby positively displacing fluids within cavities 18 and providing the fluids such as hydrocarbons with the necessary lift to overcome the hydrostatic head. Following actuation of the progressive cavity pump 12 , hydrocarbons are lifted through the annulus and enter the annular portion 120 . The hydrocarbon flow acts on the lower face of the protrusion 84 and creates a pressure differential across the protrusion 84 . Above a predetermined level, the pressure overcomes the biasing of the spring 88 at which point the moveable member 80 is pushed upwardly within the body member 11 . Upward movement of the moveable member 80 causes the bypass ports 42 in the middle sub 40 to be obturated by the sidewall of the moveable member 80 and thus the first annular portion 110 is no longer in fluid communication with the bypass ports 42 . Once the radial protrusion 84 clears the collar 102 , the protrusion 84 no longer acts as an impediment to fluid flow within the annulus and there is fluid communication between the second or lower annular portion 120 and the first or upper annular portion 110 . Therefore, hydrocarbons can be produced through the annulus 110 , 120 when the progressive cavity pump 12 is in use.
[0058] Should the progressive cavity pump 12 cease to function, hydrocarbons are no longer displaced upwardly within the annulus and there is no lift to overcome the hydrostatic head. As a result, the urging of the spring 88 becomes the dominant force acting on the moveable member 80 and the moveable member 80 returns to its default position under the urging of the spring 88 such that the radial protrusion 84 contacts the collar 102 and the openings 82 in the side wall of the moveable member 80 are once again positioned adjacent the bypass ports 42 to open the second fluid flow path and bypass the pump 12 .
[0059] The invention allows fluids to circumvent the progressive cavity pump 12 without the conventional removal of the rotor 16 and consequent downtime in the wellbore. As a result of the apparatus 10 according to the invention certain procedures are facilitated. For example, chemicals, well treatments, etc. can be injected through the second fluid flow path into the reservoir by passing the progressive cavity pump 12 . Additionally, the invention has the advantage that once the progressive cavity pump 12 is no longer in use, the second fluid flow path allows sand downstream of the pump 12 to travel through the bypass ports 42 by means of gravity fall back, such that the sand settles outwith the production tubing and without creating a sand plug above the progressive cavity pump 12 .
[0060] Modifications and improvements can be made without departing from the scope of the invention.
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An apparatus for selectively controlling fluid flow. The apparatus includes a body member having a throughbore formed therein. The apparatus also includes at least one bypass port formed in the body member and a rotatable member arranged for insertion and rotation within the throughbore of the body member. The rotatable member in the throughbore creates first and second annular portions. The apparatus further comprises a moveable member, wherein the moveable member is moveable between a first configuration which defines a first fluid flow path between the first and second annular portions and a second configuration which defines a second fluid flow path between the first annular portion and the at least one bypass port. The moveable member is typically moveable between the first and second configurations in response to fluid flow along the first fluid flow path.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional Application Ser. No. 60/999,089, filed on Oct. 16, 2007, the disclosure of which is fully incorporated by reference herein.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates to anesthesia delivery and a device for adjustably supporting the mandibular region of a patient to minimize airway compromises during surgical therapeutic and/or diagnostic procedures. It may also be utilized to assist a practitioner via position support/stabilization during mask ventilation or laryngoscopy. The invention further relates to an improved method for using the aforesaid device during and after certain surgeries.
[0004] 2. Background of the Invention
[0005] Monitored Anesthesia Care (or “MAC” anesthesia) and Total Intravenous Anesthesia (or “TIVA”) are two common means for delivering appropriately titrated doses of drugs to a patient along with anesthetic topicalization or infiltration by the surgeon at the operative site. MAC anesthesia can be used with localized or regional anesthetics, such as spinals, epidurals, topicals and peripheral nerve blocks, for providing the patient with a temporary numbing or loss of feeling and movement at a preferred, surgical location. One risk of using the MAC or TIVA anesthetic technique is that an upper airway compromise can, and often does, occur. And an unattended interference with a free exchange of respiration predisposes patients to a higher incidence of morbidity/mortality.
[0006] During many surgical procedures, upper airway obstruction can and does occur, in varying degrees, with patients whose level of consciousness is depressed by sedation/MAC/TIVA techniques. Upper airway obstruction is usually caused by a loss of tone in both the external and internal neck (or sub-mandibular) musculature, i.e., those muscles that provide direct and indirect support to the skull base itself, the mandible, the tongue and soft palate, as well as the structures of the pharynx and larynx. Collectively these structures are referred to as the Anterior Triangle of the Neck (ATN). Because of this diminished tonicity, the upright and balanced position of the jaw and skull are negatively impacted upon while the tongue and soft palate begin to approximate the posterior pharyngeal wall thereby compromising free respiratory exchange. Hyoid cartilage musculature also relaxes resulting in the epiglottis obstructing the larynx. One basic technique known for keeping the patient's airway open is to tilt the head back, lift the chin upwards and anteriorly displace the mandible. This is sometimes referred to as the triple airway maneuver.
[0007] For keeping the patient's airway unobstructed, many anesthetists start with the aforementioned chin-lift maneuver, i.e., manually lifting and then holding the patient's chin upwards. That maneuver maintains proper head tilt and anterior mandible displacement resulting in improved alignment of the airway structures. Another option, the jaw-thrust maneuver, is performed by an anesthetist placing his or her hands at both sides of the patient's mandible and laterally thrusting the jaw forward. Both methods require the anesthetist to manually provide external airway position support to varying degrees throughout the duration of the surgery.
[0008] In some MAC/TIVA anesthesia cases, an oropharyngeal or nasopharyngeal airway may be employed to maintain and improve airway patency. An oropharyngeal airway is a plastic, disposable, semi-circular shaped device that, when properly situated, will hold the tongue away from the posterior wall of the pharynx. The nasopharyngeal airway remedies similar obstructions occurring in the region of the soft palate. Even with the use of such devices, the patient's head, neck and chin must still be maintained in a proper alignment. Surgical procedures that employ MAC/TIVA techniques can range from a few minutes to several hours in duration. During that period, the anesthetist must continuously administer sedative medications, assess the patient's response to same as well as changes in the level of surgical stimuli, all the while monitoring and documenting vital signs on the patient's chart. Other factors, such as the surgical logistics, can make performing the noted airway maneuvers awkward and preclude the anesthetist from more efficiently performing his/her other responsibilities.
[0009] Still other disadvantages posed by the necessity to manually prevent airway obstruction include: restricting ergonomics of the anesthetist by requiring near constant contact with the patient's head, neck and mandibular region, thereby impeding the anesthetist from performing his or her other tasks, such as delivering medications and observation and monitoring of patient response as well as procedural documentation. The patient's relative positioning on the operating room table can make it even more difficult to maintain constant upward deflection of the chin especially during prolonged surgical procedures. The anesthetist's arms, hands and fingers can become unnecessarily fatigued and/or stiff from having to maintain the required application of forces for airway maintenance for prolonged intervals.
[0010] For the foregoing needs, it is evident that the patient's mandibular support should create an upward extension (albeit with only the slightest of force) to cause his or her head to remain tilted backwards during the surgical procedure. That is why the semi-flexible but not adjustable, hands-free chin lift of Reddick U.S. Pat. No. 6,969,366 is wedged under the patient's chin and against the upper chest, or manubrial region. The foregoing device was an alternative to the pitchfork-like chin support banded behind the patient's neck in Rotramel U.S. Pat. No. 6,171,314, and the steel framed, neck support of Davies U.S. Pat. No. 4,782,824. And all of those represent a significant leap in patient comfort over the banded, sling support means depicted in Carden U.S. Pat. No. 5,632,283.
[0011] In other instances, neck supports have been designed and patented for non-anesthetic reasons. For instance, the one piece cervical appliance of Mundell U.S. Pat. No. 4,700,697 is meant to assist the wearer overcome sleep apnea concerns. A soft but solid molded support block can be strapped about the wearer's neck for non-medical reasons according to Williams U.S. Pat. No. 7,055,908. It represents an improvement over the chin resting sling of Palley U.S. Pat. No. 4,565,408. And the ventilated neck brace of Bugarin U.S. Pat. No. 6,409,694 claims adjustability along its width and length.
[0012] Numerous other cervical collars include the one piece foam rubber neck wrap of Cheatham U.S. Pat. No. 6,926,686, a predecessor model per Newton U.S. Pat. No. 4,232,663, and a spring-loaded, wrap around collar like that shown in Gorsen U.S. Pat. No. 4,827,915. There is also the wrap around, split assembly of Bender U.S. Pat. No. 5,275,581. The cervical collar of Martin U.S. Pat. No. 6,726,643 claims automatic adjustability; while in Garth et al. U.S. Pat. No. 7,141,031, that cervical collar has an end-supported chin strap.
[0013] The inflatable cervical device of Rogachevsky U.S. Pat. No. 5,752,927 has four separate chambers for holding the wearer's neck in a neutral position, i.e. substantially horizontal or forward facing, during traction. It has no obvious contact at its support base with the wearer's upper chest/manubrium and its chin support is an “add on” that would not appear to provide any neck/mandible support regardless of the degree of inflation imparted therein. Finally, this prior art device would not be easy to use. Unlike the present invention, the prior art device would require fastening, with Velcro straps, completely about the neck of its wearer. With such complicated “plumbing”, it would be expected to require sterilization before reuse, rather than being disposable per se.
SUMMARY OF THE INVENTION
[0014] It is a principle object of this invention to provide an external airway position support device that will overcome the shortcomings of the prior art devices. It is another object to provide that device with some versatility, in terms of relative height extendibility. Another principle object is to provide a device that will allow a practitioner to monitor and control the juxtaposition of the head, chin and neck during procedures in which lesser or greater degrees of sedation/analgesia are required.
[0015] Still another principle object is to provide an external airway position support that can be held in place, beneath the patient's mandibular region, with adhesive means rather than requiring any around-the-neck straps of any sort and/or over the top of the head slinging mechanisms like those shown in the prior art.
[0016] Another object of this invention is to provide an external airway position support device that is easy to use on a patient while sitting, partially reclining, supine or laying lateral to one degree or another, either face up or face down. Another object is to provide an external airway position support that is lightweight and inexpensive to make, use and operate. A still further object is to provide a position support device that is readily disposable after use.
[0017] With the various embodiments of this invention described below, an anesthetist can more efficiently provide patient care during MAC and/or TIVA anesthesia, as this device makes it unnecessary for the anesthetist to continuously perform the required intricate airway maneuvers. Accordingly, several main objects and advantages of the present invention include: (a) not requiring the anesthetist to maintain substantially continuous physical contact with the patient's external airway at all times; (b) allowing the anesthetist less restricted movement around the patient's positioning; (c) freeing up the anesthetist to perform his or her other tasks, including administering medications, procedural observation, monitoring and documentation of respective details and responses; (d) rendering less critical the choreographing of operating room table placement and patient positioning in order to maintain the appropriate force vectors on the external airway during long surgical procedures; (e) preventing the anesthetist's arms, hands and fingers from becoming unnecessarily fatigued or stiff as would otherwise be the case when having to continually provide manual airway support; (f) avoiding the need to induce general anesthesia when local anesthesia would otherwise suffice with supplemental sedation/analgesia thereby alleviating other potential detriments such as sore throat, an increased propensity to nausea/vomiting, and injury to dentition or mucosal structures; (g) providing stable, balanced and constant external airway position support in all patients who undergo MAC/TIVA techniques; and (h) providing a disposable method for hands-free support of the external airway allowing proper alignment of anatomic structures of the airway, resulting in improved respiratory exchange, thereby preventing and/or resolving obstruction.
[0018] Further objects and advantages are to provide a device which can be used easily and safely, which is inexpensive to manufacture, and because of same, is readily disposable after use. The device may also be used to provide airway positioning support during mask ventilation and for assisted positioning during laryngoscopy. Still further objects and advantages will become apparent from a consideration of the ensuing description and drawings.
[0019] The present invention is a hands free, external airway position support device for use on patients undergoing surgical, therapeutic and/or diagnostic procedures. It is meant to adhere to the patient at the base of the jaw and at the base of the neck so that no wrap around neck or head sling attachment means are required. Preferred embodiments are one or two piece foam units held in place with glue or adhesive between the patient's chin/neck or jaw and upper chest/mandible. More preferred embodiments employ sections of hook and loop (or Velcro) tape with the latter sections being glued directly onto the patient's chin and upper chest. Alternate embodiments may include a plurality of inflatable segments that alone, or in combination with additional foam components, assist in extending the patient's neck and maneuvering his/her chin upward and outward. As this device will be relatively inexpensive to manufacture and not overly complicated in design and/or mechanics, it can be disposed of after use rather than requiring sterilization for reuse.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Further features, objectives and advantages of the present invention will become clearer when referring to the following detailed description of preferred embodiments made with reference to the accompanying drawings in which:
[0021] FIG. 1 is a perspective side view of a first embodiment of unitized EAP support device according to the invention properly installed between a patient's chin and manubrial regions;
[0022] FIG. 2A is a schematic side view of the unitized manubrium arch and crescent lever component from FIG. 1 ;
[0023] FIG. 2B is a schematic side view of the two piece manubrium arch and crescent lever components from a second embodiment of EAP support device according to this invention;
[0024] FIG. 3 is a top perspective view of the manubrium arch component from FIG. 2B ;
[0025] FIG. 4 is a bottom perspective view of the manubrium arch component from FIGS. 2B and 3 ;
[0026] FIG. 5 is a front schematic view of the FIG. 3 manubrium arch component positioned on a patient's upper chest or manubrium;
[0027] FIG. 6 is a top perspective, right side view of the crescent lever component from FIG. 2B ;
[0028] FIG. 7 is a side schematic view of the crescent lever component from FIG. 6 flexed downwardly prior to installation between a patient's chin and upper chest;
[0029] FIG. 8 is a top schematic view of an embodiment of chin/mandible grip component for the present invention;
[0030] FIG. 9 is a front schematic view of the chin/mandible grip component from FIG. 8 as it would appear when adhesively bonded to a wearer's chin according to the invention;
[0031] FIG. 10 is a close up, left side schematic view of the chin/mandible grip component from FIG. 9 held in place beneath the wearer's chin;
[0032] FIG. 11 is a front perspective view of a third embodiment of mandibular lift device according to this invention;
[0033] FIGS. 12A , B and C are side schematic views of the mandibular lift device from FIG. 11 positioned between a wearer's chin and upper chest prior to inflation ( FIG. 12A ); at a midpoint of inflation ( FIG. 12B ); and at or near full inflation ( FIG. 12C );
[0034] FIG. 13 is a top perspective view of a fourth embodiment of mandibular lift device according to this invention;
[0035] FIG. 14 is side schematic view of the FIG. 13 device positioned about the neck of a patient; and
[0036] FIG. 15 is a flowchart depicting the installation method steps for one embodiment of this invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0037] Referring to FIGS. 1 and 2A , there is shown a first preferred embodiment of external airway position support device, generally 50 . In this version, the two main components, a manubrium arch 52 and crescent lever 54 , are unitized, i.e. made from one section of material such as foam or the like. This one-piece device 50 serves as an EAP support when situated at the base (or underside) of crescent lever 54 to the wearer/patient's manubrium 56 and beneath said wearer/patient's chin, jaw or mandible region 58 . Device 50 may be glued directly to the wearer/patient P at one or both ends. Such adhesion provides for a strong connection between manubrium 56 and mandible 58 regions. Alternately, one or both ends of device 50 may include sections of hook and eye tape (or Velcro) with corresponding sections of tape glued to the manubrium 56 and/or mandible 58 regions of patient P as explained herein. A representative section of such tape 55 is glued to the patient's chin or mandible 58 in FIG. 1 . It would adhere to a corresponding section of Velcro tape 82 at the uppermost curve for the crescent lever arm 80 of crescent lever 54 .
[0038] Another section of Velcro tape 66 adheres to the bottom 62 of manubrium section 52 as shown. The underside to manubrium arch 52 is kept substantially planar for better resting on, and adhesion to, the patient's manubrium 56 for many therapeutic/diagnostic surgical procedures. Optionally, device 50 may be left in place for continued airway support of the patient P in the post-anesthesia care unit. In alternate embodiments (not shown), the manubrium section of this device may adhere directly to a rectangular adhesive patch glued to the patient's upper chest. At least one of the manubrium base and the upper surface of said patch should be provided with one or more known surgical adhesives. In some instances, an adhesive-to-adhesive connection may be desired, or even preferred, over the Velcro-to-Velcro manubrium connection described above.
[0039] The main elements for manubrium arch 52 and flexible crescent lever 54 can be fabricated from a flexible, elastically expandable foam-like material. Representative examples of same include, but are not limited to: a plastic, such as polyethylene, polyvinyl chloride, rubber and/or similar natural and synthetic substances. As flexibility is less critical for the manubrium arch 52 , it can be made from still other alternative materials suitable for temporarily adhering to a base of flexible crescent lever 54 .
[0040] Referring to FIGS. 2B through 7 , there is shown a second embodiment of the present invention. In the FIGURES for alternate embodiments, common components are commonly numbered, though in the next “hundred” series. As such, the second version of this invention for an EAP support device, generally 150 , has two separate and distinct elements, a manubrium arch component 152 (as best seen in accompanying FIGS. 3-5 ) and a crescent lever component 154 that are joined together with corresponding sections of Velcro tape, generally 160 , adhered to adjoining ends of said components 152 and 154 , as best seen in FIGS. 2B , 3 and 5 . With a flexible crescent lever component 154 , this two-piece device 150 can also serve as a suitable EAP support when situated at its base to manubrium arch component 152 and then to a chin/mandible grip 155 beneath a wearer/patient's mandible region 158 , the latter grip component being similar to the one used with the first embodiment in FIGS. 1 and 2A .
[0041] As shown in FIGS. 3 through 5 , this embodiment of manubrium arch 152 has a flat underside 162 and curved upper surface 164 . Alternatively, upper surface 164 of manubrium arch 152 may consist of several consecutive planar portions giving that upper surface more of a polygonal appearance (not shown). To the flat underside 162 , there is included a first adhesive layer 166 of such composition that any existing gaps/contours may be filled. First adhesive layer 166 enables the device 150 to be fixedly, albeit temporarily, installed to the manubrium 156 of patient P, slightly below the anterior base of that patient's neck.
[0042] To the upper surface 164 (whether curved or polygonal), there is positioned a wide section 172 of hook and loop (or Velcro) tape. Tape section 172 joins to a corresponding Velcro component 174 on the lowermost base 176 of flexible crescent lever 154 . That lowermost base can be made substantially planar. Alternatively, it can be provided with a slight concave, or inward arch for better adhering to the section of Velcro tape positioned on the arched or curved upper surface 164 of manubrium arch 152 .
[0043] Per FIGS. 6 and 7 , a curved, slightly flexible crescent lever arm section 180 extends upwardly from the lowermost base 176 of crescent lever 154 . As the chins/upper neck regions of patients vary in size, width, etc., it is possible to make crescent lever components in varying widths and/or lengths. This is especially true when using this device for younger, smaller wearer/patients.
[0044] Atop an uppermost region of crescent lever arm section 180 , particularly on the outside of same, there is positioned a strip of Velcro tape 182 . It is meant to attach to the corresponding central Velcro component 184 on the outside and underside of chin/mandible grip 155 adhesively secured to the wearer/patient's chin and/or uppermost neck 188 . See especially, FIGS. 8 through 10 . In the embodiment shown, nearly half of the specially curved configuration for chin/mandible grip 155 is covered with a Velcro tape, hook and loop material, from side edge to side edge. Alternatively, only the center most regions of chin/mandible grip 155 need to have a matching Velcro component 184 .
[0045] Several surgically acceptable adhesives are known. Many alternatives allow the anesthetist and surgical team to select from a menu of options in the event a patient may know of past allergic reactions to some. The use of adhesives is preferred over past known attachment methods for many cervical collars. These past collars were belted about the wearer's neck, and connected with Velcro® straps, buckles and/or snaps. They would preclude a rapid removal of the device in the event of a surgical emergency. Ideally, it is preferred that the patient/wearer's neck be kept accessible for just such an emergency. In still other known devices, one or more elastic bands were used to “sling” the wearer's chin upward.
[0046] In accompanying FIGS. 11 , 12 A, 12 B and 12 C, there is shown a third embodiment of EAP device, generally 250 , that has an overall circular appearance in top view. Before inflation, device 250 has a somewhat Z-shaped design with a fattened or rounded, central region 251 . It may also resemble the symbol for a hurricane on weather maps.
[0047] Device 250 may be made from an inflatable plastic liner preconfigured to have a lowermost chest contacting, or manubrium portion 252 and an upper or top mandibular portion 254 on opposite sides of central region 251 . The side edge 255 , between front and rear faces to device 250 , is contoured to resemble a continuous V-shape. With that configuration, device 250 can serve as a suitable chin-rest when positioned beneath the mandibular region 258 of patient P.
[0048] As shown, both the lower portion 252 and top portion 254 have separate valves, 252 v and 254 v, respectively. When connected to a pump, gas can or other air supplying means (not shown), each valve causes a ball shaped bladder 257 to expand thereby forcing either arm portion, the lower chest contacting 252 or top mandibular portion portion 254 , to further separate or duly spread apart from the main central region 251 .
[0049] This alternate design for an EAP support device is relatively reversible. With its universal V-shaped side edge 255 , the entire device 250 can be rotated 180 degrees for situating its lower chest contacting portion 252 against the patient's manubrium 256 , and its upper mandibular portion 254 against the patient's mandible 258 . In yet another alternate (not shown), reversibility is not as critical. Therein, the device side edge would not be uniformly V-shaped, but only cupped inwardly for serving as a patient chin rest. The side edge to the lowermost portion would be kept substantially planar for better resting, and adhesion, to the patient's manubrium.
[0050] It is understood that the valves for the foregoing embodiment may be situated on the body proper of device 250 for inflation with a bulb inflation mechanism and/or a large, luer-lock type syringe as is available in most operating rooms. Also, depending on the valves and maximum pressures desired, a mere can of compressed air could rapidly couple and fill device 250 after it is duly situated on at least one side to the patient's chest or chin. For greater control, it is preferred that the same valve through which air is added can serve as a “bleeder valve”, through which only some air can be removed if slightly overfilled, or through which most of the air can be extracted after the surgery has finished. The device might also be left in place for continued airway support in the post-anesthesia care unit.
[0051] Referring to FIGS. 13 and 14 , there is shown a fourth embodiment wherein device 350 has a plurality of chambers 350 c that upon inflation will accordion upwardly from a starting position to expand between the patient's upper chest 356 and chin 358 . As shown, device 350 is essentially C-shaped, though in the embodiment at FIG. 13 , a structural vertical reinforcement 355 gives the device 350 somewhat of a hinged appearance. Regardless, it is preferred that regardless of the number of baffles comprising device 350 , they should all be filled (and subsequently deflated) through a single, common valve 350 v.
[0052] For illustrative purposes, the lower end of device 350 is provided with a first layer of adhesive 366 L for sticking to a patient's manubrium 356 and/or partially about the anterior base of their neck. On the opposite end, the uppermost surface of device 350 has its own adhesive layer 366 U for adjoining same to the wearer's chin, or mandibular region 358 .
[0053] Any of the foregoing devices 50 , 150 , 250 or 350 can be fabricated from a flexible, elastically expandable material. Representative examples of same include, but are not limited to: a plastic, such as polyethylene, polyvinyl chloride, rubber and/or similar natural and synthetic substances.
[0054] FIG. 15 is a block diagram chart showing one preferred method for installing the device of this invention on a wearer/patient. It includes the steps of:
1. Selecting the proper size of device for the patient's neck dimensions (i.e. adult versus child, thinner versus heavier wearer, etc.). 2. The device is adhered at its base to the patient's upper chest or throat. 3. Adhesive is next applied to where the upper regions of this device will contact with the underside to the patient/wearer's chin or mandible.
[0058] For the inflatable embodiments at FIGS. 11 through 14 , next step 4 calls for gradually inflating the device such that through expansion, the patient's neck is progressively extended and his/her mandible advanced upwardly and outwardly to the required degree. As this step is unnecessary for the non-inflatable device versions shown at FIGS. 1 through 7 , it is duly marked with dashed lines in the process flowchart steps of FIG. 15 .
[0059] Following completion of the surgery, optional step 5 for the inflatable versions calls for purposefully deflating the device (either fully or partially). Finally, step 6 entails discarding a fully removed device rather than subjecting it to sterilization and reuse.
[0060] In some instances, it may prove prudent to leave any of these devices on the patient proper through some portion of post-anesthesia care and post-surgical recovery. In that manner, the device and method of this invention can further assist in providing needed, supplemental support for a recovering patient's airway passages.
[0061] The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative, not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes that come within the meaning and range of equivalency of the claims are to be embraced within their scope.
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A hands free, external airway position support device for use on a patient undergoing a surgical, therapeutic and/or diagnostic procedure. The device adheres to the patient at the base of his or her chin, jaw or neck so that no wrap around neck or head sling attachment means are required. When installed, the device will extend the patient's neck and maneuver his or her chin upward and outward, away from the base of the neck. As this device will be relatively inexpensive to manufacture and not overly complicated, it can be disposed of after use rather than requiring sterilization for reuse.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a synchronous rectifying DC-DC converter and, in particular, to dead time control suitable for high-frequency switching.
[0003] 2. Description of the Related Art
[0004] As portable devices become multifunctional, more and more power supply circuits with different operating voltages are incorporated into the portable devices. For example, a cellular phone includes power supplies such as those for a baseband IC, LCD driver, and power amplifier module with different operating voltages. As power supply circuits for converting a voltage supplied from a battery to an operating voltage of each power supply circuit, synchronous rectifying DC-DC converters have been known in which a switching transistor and a commutating transistor are connected in series between an input power supply and a ground and are turned on and off in a complementary manner to supply a DC voltage to a capacitor of a smoothing circuit connected in parallel with the commutating transistor. In the synchronous rectifying DC-DC converters, power efficiency is increased by controlling dead time so as to prevent a short-circuit current from flowing through the switching transistor and commutating transistor, as disclosed in Japanese Patent Laid-Open No. 2001-112241, for example. Examples of dead time control methods conventionally used include a method in which a certain delay time is inserted in a gate signal controlling the drive of the switching transistor and commutating transistor and alternatively a method in which an output voltage of an error amplifier is shifted to produce a dead time according to the amount of the shift.
[0005] The dead time control method described above is feasible when there is a sufficient time in a low-frequency range, and may improve power efficiency to some extent by optimization of dead time. However, a trend in DC-DC converter design for portable devices is that inductance and capacitor constants are reduced by increasing switching frequency, thereby reducing the size of the components. It is predicted that switching operation at 10 MHz or higher will be achieved in the near future. In such a high-frequency range, there will be little time available for dead time control.
[0006] In addition to the circumstances, there is another trend that variations in typical values of parameters (such as the DC resistance of an inductor, the on-resistance of a PMOS transistor, and the switching period of an oscillator) of the DC-DC converter are increasing. Therefore, there is a demand for development of a dead time control method capable of strictly controlling the drive of a commutating transistor with a high degree of accuracy by taking into consideration variations in parameters specific to individual products.
[0007] For example, if the lower limit of the input voltage of an internal battery (lithium ion battery) of a portable device is 2.8 V, the output voltage of the DC-DC converter is 1.8 V, the upper limit of output current is 1.2 A, the DC resistance of the inductor is 120 mΩ, the on-resistance of the MOS transistor is 350 mΩ, and the maximum error rate of switching frequency is 15%, then the allowable dead time is limited to 15 nsec or less. It is very difficult for the conventional dead time control methods, which rely on a static approach, to perform dead time control within such a severely limited time.
[0008] Therefore, an object of the present invention is to provide a dead time control method that identifies the allowable margin of dead time that is specific to a synchronous rectifying DC-DC converter, recognizes a critical situation in which a commutating transistor cannot be turned on for a reason such as a temporary variation in an output voltage of the synchronous rectifying DC-DC converter, and adaptively prevents the commutating transistor from being turned on in the critical situation.
SUMMARY OF THE INVENTION
[0009] To achieve the object, a synchronous rectifying DC-DC converter according to the present invention is a synchronous rectifying DC-DC converter increasing or decreasing an input voltage to an output voltage, including: a switching transistor being turned on and off at a duty cycle according to the ratio between the input voltage and the output voltage to stop and start the supply of the input voltage to convert the input voltage into a pulsed voltage; a commutating transistor being tuned off in synchronization with turning on of the switching transistor; a ramp generator outputting a ramp synchronizing to a switching period of the switching transistor; an error amplifier into which a feedback signal of the output voltage and a reference voltage for the output voltage are input; a holding circuit for temporarily holding a peak voltage of the ramp output from the ramp generator; a variable amplifier amplifying the peak voltage held in the holding circuit in accordance with a first value stored in a nonvolatile memory; a first comparator comparing the voltage of the ramp with an output voltage of the error amplifier and, when the voltage of the ramp is lower than the output voltage of the error amplifier, outputting a logic signal for turning on the switching transistor and, when the voltage of the ramp exceeds the output voltage of the error amplifier, outputting a logic signal for turning off the switching transistor; a second comparator comparing an output voltage of the variable amplifier with the output voltage of the error amplifier and, when the output voltage of the variable amplifier exceeds the output voltage of the error amplifier, outputting a logic signal for turning on the commutating transistor and, when the output voltage of the variable amplifier is lower than the output voltage of the error amplifier, outputting a logic signal for turning off the commutating transistor; a third comparator comparing the output voltage of the variable amplifier with the voltage of the ramp and, when the output voltage of the variable amplifier exceeds the voltage of the ramp, outputting a logic signal for turning on the commutating transistor and, when the output voltage of the variable amplifier is lower than the voltage of the ramp, outputting a logic signal for turning off the commutating transistor; a delay circuit inserting a delay time in a logic signal output from the first comparator; and an AND circuit performing an AND operation on logic signals output from the delay circuit, the second comparator, and the third comparator. Here, the switching transistor is turned on or off on the basis of a logic signal output from the first comparator, and the commutating transistor is turned on or off on the basis of a logic signal output from the AND circuit.
[0010] According to the configuration, the allowable margin of dead time specific to the synchronous rectifying DC-DC converter can be identified and, in a critical situation in which the commutating transistor cannot be turned on, the situation can be recognized and the commutating transistor can be adaptively prevented from being turned on.
[0011] Here, the first value is preferably equal to 1 minus the sum of the amount of gate charge and discharge time of the switching transistor and the amount of gate charge and discharge time of the commutating transistor divided by the sum of a typical value of the switching period and a period error of the ramp. This enables dead time control with variations in elements that are specific to the synchronous rectifying DC-DC converter being taken into consideration.
[0012] The delay time inserted by the delay circuit is preferably equal to or greater than the amount of gate charge and discharge time of the switching transistor. This enables the commutating transistor to be turned on after waiting for the switching transistor to surely turn off.
[0013] The ramp generator preferably corrects a switching period error by changing the gradient of the ramp on the basis of a second value stored in the nonvolatile memory. This is an effective means for reducing the convergence time immediately after power on or for achieving stable control.
[0014] The nonvolatile memory stores a peak voltage of the ramp measured when an input voltage exceeding an upper limit in normal operation is supplied. The first and second values described above can be calculated on the basis of the peak voltage of the ramp. For example, the second value is equal to the value of an input voltage exceeding the upper limit voltage in normal operation multiplied by a design peak value of the ramp divided by a design input voltage in normal operation multiplied by a peak voltage of the ramp measured when the input voltage exceeding the upper limit voltage in normal operation is supplied.
[0015] According to the present invention, the allowable margin of dead time that is specific to a synchronous rectifying DC-DC converter can be identified and, in a critical situation in which a commutating transistor cannot be turned on for a reason such as a temporary variation in output voltage of the synchronous rectifying DC-DC converter, the situation can be recognized and the commutating transistor can be adaptively prevented from being turned on.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 is a circuit diagram of a synchronous rectifying DC-DC converter according to an embodiment of the present invention;
[0017] FIG. 2 is a timing chart showing the relationship between a PWM pulse and dead time;
[0018] FIG. 3 is a diagram illustrating switching period error correction; and
[0019] FIG. 4 is a timing chart illustrating operation of the synchronous rectifying DC-DC converter according to the present embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0020] An embodiment of the present invention will be described with reference to the accompanying drawings.
[0021] A synchronous rectifying DC-DC converter 10 according to an embodiment of the present invention is a step-down converter for decreasing an input voltage Vin supplied from a source such as a battery to a desired output voltage Vo to supply the operating voltage Vo to a load R. The synchronous rectifying DC-DC converter 10 includes a power-supply control circuit 20 which outputs a pulsed voltage that is duty-cycle-controlled in accordance with the ratio between the input voltage Vin and the output voltage Vo and a smoothing circuit 30 which smoothes the pulsed voltage to supply the DC voltage Vo to the load R. The power-supply control circuit 20 includes a switching transistor Tr 1 , a commutating transistor Tr 2 , a ramp generator 40 , an error amplifier AMP 1 , a variable amplifier AMP 2 , comparators CMP 1 , CMP 2 , and CMP 3 , an AND circuit 51 , a logic inverter 52 , a delay circuit 71 , a latch circuit (holding circuit) 72 , a nonvolatile memory 80 , an A-D converter 82 , and D-A converters 81 and 83 . The switching transistor Tr 1 and the commutating transistor Tr 2 are connected in series between an input power-supply voltage Vin and a ground GND. The smoothing circuit 30 is a low-pass filter including an inductor L and a capacitor C connected in series between the connection point of the switching transistor Tr 1 and the commutating transistor Tr 2 and the ground GND.
[0022] The switching transistor Tr 1 is turned on and off at a duty cycle according to the ratio between the input voltage Vin and the output voltage Vo, thereby stopping and starting the supply of the DC voltage Vin to convert the DC voltage Vin into a pulsed voltage. The pulsed voltage is smoothed at the smoothing circuit 30 into the DC voltage Vo and supplied to the load R. Switching of the switching transistor Tr 1 and the commutating transistor Tr 2 is controlled in such a way that they are turned on and off in a complementary manner. For example, when the switching transistor Tr 1 is turned on, the commutating transistor Tr 2 is turned off, thereby storing energy in the inductor L. On the other hand, when the switching transistor Tr 1 is turned off, the commutating transistor Tr 2 is turned on, thereby forming a current path for supplying the energy stored in the inductor L to the load R.
[0023] While an example is given in which a PMOS transistor is used as the switching transistor Tr 1 and an NMOS transistor is used as the commutating transistor Tr 2 for simplicity of the circuit configuration, the present invention is not limited to the example. Both transistors Tr 1 and Tr 2 can be implemented by NMOS transistors by adding a bootstrap circuit. Depending on applications, amplifiers such as bipolar transistors and IGBT (insulated gate bipolar transistor) may be used.
[0024] Before detailing components of the power-supply control circuit 20 , the relationship between a PWM (pulse Width Modulation) pulse for controlling drive of the switching transistor Tr 1 and the dead time of the commutating transistor Tr 2 with reference to FIG. 2 . In FIG. 2 , “T” denotes a typical value of a switching period, “Terror” denotes a switching period error, “Ton” denotes the center value of an on-period of the switching transistor Tr 1 , “ΔTon” denotes the length of time for adjusting the on-period by PWM control, “t 1 ” denotes a gate charge/discharge time of the switching transistor Tr 1 , and “t 2 ” denotes a gate charge/discharge time of the commutating transistor Tr 2 . The PMOS gate signal represents a logic signal (negative logic) input in the gate terminal of the PMOS transistor (switching transistor Tr 1 ) and the NMOS gate signal represents a logic signal (positive logic) input in the gate terminal of the NMOS transistor (commutating transistor Tr 2 ). As can be seen from FIG. 2 , there is a certain delay time t 1 in rising and falling of the switching transistor Tr 1 and a certain delay time t 2 in rising and falling of the commutating transistor Tr 2 . The minimum length of dead time required for dead time control in one switching period is (t 1 +t 2 ). Here, the following equations hold for the duty and the allowable margin Tmargin for the dead time (t 1 +t 2 ) in each switching period.
[0000] ( T on+Δ T on)/( T+T error)= F ( Io, Vo )/ V in (1)
[0000] F ( Io, Vo )=( R on+ Rdc )×( Io+ΔIo )+( Vo−ΔVo ) (2)
[0000] T margin≦( T+T error)−( T on+Δ T on)−( t 1+ t 2) (3)
[0025] Here, “F (Io, Vo)” is a function of Io and Vo, “Ron” is the on-resistance of the switching transistor Tr 1 , “Rdc” is the DC resistance of the inductor L, “Io” is the average value of output current supplied to the load R, “ΔIo” is an increase or decrease in the output current due to a load variation, “Vo” is the typical value of the output voltage supplied to the load R, and “ΔVo” is an increase or decrease in the output voltage due to a load variation.
[0026] Returning to FIG. 1 , a configuration of the ramp generator 40 will be described. The ramp generator 40 includes a transistor Tr 3 , a capacitor Cramp, an oscillator 60 , switches S 1 and S 2 , and a logic inverter 52 . The oscillator 60 is an oscillation circuit oscillating at an oscillation period T. The oscillation period T defines the switching period T of the switching transistor Tr 1 . The transistor Tr 3 operates in a linear region and controls the gain of a charging current Iramp flowing through the charging path of the capacitor Cramp. A logic signal supplied from the oscillator 60 to the switch S 1 is inverted by the logic inverter 52 and is provided to the switch S 2 . Accordingly, the switches S 1 and S 2 are turned on and off in a complementary manner at the oscillation period T. The switch S 1 is turned on at the start of the switching period T and remains on until right before the end of the switching period T while the switch S 2 is turned off at the start of the switching period T and remains off until right before the end of the switching period T. In this period, a constant charging current Iramp flows from the input voltage Vin into the capacitor Cramp through the transistor Tr 3 . The capacitor Cramp is charged with a ramp voltage Vramp and the potential of a node A connected to one end of the capacitor Cramp linearly rises from 0 V. Then, during a short period of time from the end of the switching period T until right before the start of the next switching period T, the switch S 1 is turned off and the switch S 2 is turned on. At this moment, the charge in the capacitor Cramp is instantly discharged and the potential at the node A instantaneously decreases to 0 V. By periodically controlling the switching of the switches S 1 and S 2 in this way, a ramp (triangular wave) Vramp synchronizing to the switching period T is output from the node A.
[0027] A method for correcting a switching period error Terror will now be described with reference to FIG. 3 . The switching period error Terror is caused by a variation in an element constant of the oscillator 60 and is an error specific to the oscillator 60 . The following equations hold for the switching period error Terror.
[0000] V ramp, pk=I ramp×( T+T error)/ C ramp (4)
[0000] tan θ= V ramp, pk /( T+T error) (5)
[0000] tan θ=( G 1 ×V in)/ C ramp (6)
[0028] Here, “Vramp, pk” represents the peak voltage value of the ramp voltage “Vramp” with which the capacitor “Cramp” is charged, “θ” represents the gradient (time change rate) of the ramp voltage “Vramp”, and “G1” represents the conductance of the transistor Tr 3 . As can be seen from FIG. 3 , by controlling the gate potential of the transistor Tr 3 to change the conductance of the transistor Tr 3 , the gradient θ of the ramp voltage “Vramp” can be adjusted to reduce the switching period error “Terror” to virtually zero. The peak ramp voltage “Vramp, pk” of the ramp is not necessarily constant but can change with variations in power supply of the input voltage Vin. The latch circuit 72 temporarily holds the peak voltage “Vramp, pk” of the ramp of each switching period and updates the ramp peak voltage value temporarily held in it to the peak voltage of the ramp of the next switching period.
[0029] How to calculate “G1” will be described below. The following relationship holds between “G1” and the peak voltage “Vramp, pk”.
[0000] G 1=( T+T error)/ T (7)
[0000] G 1=( V in, test× V ramp, dv )/( V in, dv×V ramp, pk ) (8)
[0030] Here, “Vin, test” represents a test voltage of the input power supply Vin during testing, “Vin, dv” represents the nominal voltage of the input power supply Vin in the circuit design (or in the specifications of the circuit), and “Vramp, dv” represents the nominal peak voltage of the ramp Vramp in the circuit design. It should be noted that “Vramp, pk” in Equation (8) is the peak voltage of the ramp in the previous switching period that is temporarily held in the latch circuit 72 . “Vin, test” is a test bias voltage that is exploratively input in the DC-DC converter 10 in order to calculate “G1” described above and “G2”, which will be described later. For example, “Vin, test” is preferably a voltage exceeding the upper limit by a certain value or more in the specifications of the DC-DC converter 10 and within the recommended operating power-supply voltage range of the transistor. The test bias voltage may be input in the DC-DC converter 10 in a stage before shipping of the product, for example.
[0031] The test peak voltage “Vramp, pk” is converted into digital data by the A-D converter 82 and the digital data is stored in the nonvolatile memory 80 . The test peak voltage “Vramp, pk” stored as the digital data in the nonvolatile memory 80 is used by well-known reading means such as an external tester and is used in calculation of “G1”. “G1” calculated according to Equation (6) is converted to the gate potential of the transistor Tr 3 and is stored in the nonvolatile memory 80 as digital data. In operation of the DC-DC converter 10 , the D-A converter 83 supplies a gate potential corresponding to “G1” stored in the nonvolatile memory 80 to the gate terminal of the transistor Tr 3 . Upon the supply of the gate potential, the gradient of the ramp Vramp is corrected so that the switching period error “Terror” becomes zero. The switching period error correction is not necessarily required for performing dead time control but is effective for reducing convergence time immediately after power on or for achieving stable control.
[0032] Returning to FIG. 1 , operation of the error amplifier AMP 1 and comparators CMP 1 , CMP 2 , and CMP 3 will be described, with reference to FIG. 4 as needed. The error amplifier AMP 1 has an integral transfer characteristic. A feedback signal of the output voltage Vo is provided to the inverting input terminal of the error amplifier AMP 1 while a reference voltage (nominal output voltage) for the output voltage Vo is provided to the noninverting input terminal of the error amplifier AMP 1 . An output voltage Voff of the error amplifier AMP 1 is provided to the inverting input terminal of the comparator CMP 1 while a ramp Vramp output from the ramp generator 40 after frequency error correction is provided to the noninverting input terminal of the comparator CMP 1 . As shown in the timing chart of FIG. 4 , the comparator CMP 1 compares the voltage value of the ramp Vramp with Voff. When the voltage value of the ramp Vramp is lower than Voff, the comparator CMP 1 outputs a low-level logic signal for turning on the switching transistor Tr 1 . When the voltage value of the ramp Vramp increases to a value greater than or equal to Voff, the comparator CMP 1 outputs a high-level logic signal for turning off the switching transistor Tr 1 . The signal output from the comparator CMP 1 is the PWM pulse shown in FIG. 2 . As can be seen from FIG. 4 , the value of Voff is not necessarily constant but can change to converge the difference between the feedback signal and the reference voltage which varies depending on the power consumption of the load R. The delay circuit 71 inserts a delay time in the PWM pulse output from the comparator CMP 1 . The delay time is equal to or greater than the gate charge/discharge time t 1 of the switching transistor Tr 1 . For simplicity, the delay time inserted by the delay circuit 71 is equal to the gate charge/discharge time t 1 of the switching transistor Tr 1 in the timing chart shown in FIG. 4 .
[0033] The output voltage Voff of the error amplifier AMP 1 is provided to the inverting input terminal of the comparator CMP 2 while a voltage Vt is provided to the noninverting input terminal. As shown in FIG. 4 , the voltage Vt is the voltage value of the ramp Vramp at the time point a length of time equal to the dead time (t 1 +t 2 ) before the end of a switching period. When Voff becomes equal to Vt, the right-hand side of Equation (3) becomes equal to zero. When Voff exceeds Vt, the right-hand side of Equation (3) decreases to a negative value and therefore the dead time is insufficient to control the switching of the commutating transistor Tr 2 . The comparator CMP 2 compares Voff with Vt. When Voff is lower than Vt (that is, when the dead time is sufficient to control the switching of the commutating transistor Tr 2 ), the comparator CMP 2 outputs a high-level logic signal for turning on the commutating transistor Tr 2 . When Voff becomes greater than or equal to Vt (that is, the dead time is insufficient to control the switching of the commutating transistor Tr 2 ), the comparator CMP 2 outputs a low-level logic signal for turning off the commutating transistor Tr 2 .
[0034] The ramp Vramp output from the ramp generator 40 after frequency error correction is provided to the inverting input terminal of the comparator CMP 3 whiles the voltage Vt described above is provided to the noninverting input terminal. The comparator CMP 3 compares the voltage value of the ramp Vramp with Vt. When the voltage value of the ramp Vramp is lower than Vt, the comparator CMP 3 outputs a high-level logic signal for turning on the commutating transistor Tr 2 . When the voltage value of the ramp Vramp becomes higher than or equal to Vt, the comparator CMP 3 outputs a low-level logic signal in order to turn off the commutating transistor Tr 2 at the time point a length of time equal to the dead time (t 1 +t 2 ) before the start of the next switching period.
[0035] The AND circuit 51 provides a logic signal obtained by ANDing output signals of the delay circuit 71 and the comparators CMP 2 and CMP 3 to the gate terminal of the commutating transistor Tr 2 to control the switching of the commutating transistor Tr 2 .
[0036] A method for generating the voltage Vt will now be described. The following relationship holds between the voltage Vt and the peak voltage “Vramp, pk”.
[0000] Vt=G 2 ×V ramp, pk (9)
[0000] G 2={( T+T error)−( t 1 +t 2)}/( T+T error) (10)
[0037] It should be noted that “Vramp, pk” in Equation (9) is the peak voltage of the ramp in the previous switching period that is temporarily held in the latch circuit 72 . The value of “G2” is calculated according to Equation (10) and is stored in the nonvolatile memory 80 in a stage before shipping of the product, for example. The value of “G2” is read from the nonvolatile memory 80 during operation of the synchronous rectifying DC-DC converter 10 , and is then converted by the D-A converter 81 into analog data, and the analog data is provided to the variable amplifier AMP 2 . The variable amplifier AMP 2 attenuates the peak voltage “Vramp, pk” on the basis of the value of “G2” to output the voltage Vt as shown in Equation (9).
[0038] While the commutating transistor Tr 2 is prevented from being turned on in a switching period in which Voff becomes greater than or equal to Vt in the timing chart shown in FIG. 4 , the energy accumulated in the inductor L while the switching transistor Tr 1 is on flows to the load R through a parasitic diode formed in the commutating transistor Tr 2 . It should be noted that the timing chart was prepared for illustrating a switching period in which dead time control of the commutating transistor Tr 2 is possible and a switching period in which dead time control of the commutating transistor Tr 2 is impossible, and that the voltage values Voff and Vt can vary in a different way from that shown in FIG. 4 depending on various factors such as a variation of the power consumption of the load R, an increase in resistance component due to a temperature rise and an input voltage drop during use of the battery. While the step-down DC-DC converter has been shown in the present embodiment by way of example, the principle of the dead time control according to the present embodiment is applicable to a step-up DC-DC converter as well.
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There is provided a dead time control method capable of recognizing a critical situation in which a commutating transistor cannot be turned on because of a temporary variation in an output voltage of a synchronous rectifying DC-DC converter and adaptively preventing the commutating transistor from being turned on. The synchronous rectifying DC-DC converter compares an output Voff of an error amplifier with a voltage Vt obtained by multiplying the peak voltage of a ramp by G2. When Voff becomes greater than or equal to Vt, the converter determines that dead time is insufficient to control the switching of the commutating transistor and prevents the commutating transistor from being turned on.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional application from U.S. patent application Ser. No. 09/918,283 filed on Jul. 30, 2001.
FIELD OF THE INVENTION
[0002] The present invention relates to a hinge mechanism for a portable, foldable electronic device comprising two or more positions.
BACKGROUND OF THE INVENTION
[0003] For storing various 1data, known electronic devices are available, such as notepad computers, small hand-held computers or PDA devices (personal digital assistant). The data can be viewed by means of the display of the device. The data are entered in the devices by means of a keypad or a touch screen. Also wireless communication devices, such as mobile phones, comprise a keypad and a display for storing or selecting telephone numbers. Known devices include Nokia® 8850, 7110 and 6110 mobile phones. Devices are also available having two different user interfaces, normally the user interfaces of a mobile phone and a PDA device. One such known device is Nokia® 9110 Communicator, whose first user interface (opened position) is a PDA user interface and second user interface (closed position) is a CMT user interface (cellular mobile telephone) for mobile phone functions. The device comprises separate keypads and displays for the different user interfaces. The device comprises two housing parts hinged to each other. On their inner side, the PDA user interface of the device is protected between the housing parts in the closed position of the device. The CMT user interface is on the outer side of one housing part.
[0004] A PDA/CMT device comprising two user interfaces and two different use positions is also known from U.S. Pat. No. 6,014,573. In the closed position, the device is used as a mobile phone, and in the opened position, a separate keypad and display are available. When opened, it is also possible to have e.g. a wireless connection to a communication network and to search for information by means of a browser or communication software in the device. A PDA/CMT device comprising two or more foldable housing parts is also known from U.S. Pat. No. 6,047,196. The CMT user interface is placed on the outer sides of both housing parts. One embodiment of the device also comprises a wide display which is divided into two foldable housing parts. A corresponding wide display comprising two foldable housing parts is also known from the patent publication U.S. Pat. No. 5,734,513. When the housing parts are closed, the displays remain protected therebetween. The separate displays are placed next to each other to form a wider uniform display.
[0005] It is known that devices comprising a CMT user interface only can also be provided with auxiliary functions, for example a camera, as disclosed in the application publication EP 0 963 100 A1. Electronic images produced with the camera, for example still images or video images, can be transferred to the display of the device or be transmitted in a wireless manner elsewhere in the communication network and to other CMT devices. A particular problem is induced by the placement of the camera also in the PDA/CMT device to make the use of the camera possible and simple in different positions of the device.
[0006] In known PDA/CMT devices that can be opened and closed, a problem is the placement of keys or corresponding control buttons, cursor keys, rotatable rolls or balls, rocker buttons or navigation keys in an optimal way for the use. A particular problem lies in two interfaces which are used in different positions of the device, wherein the grip of the user's hand should be simultaneously changed and/or released to make the use comfortable and to make opening of the device even possible. When opening and changing the grip, both hands are often needed. The keys for several different grips must be placed within reach of the fingers, but at the same time, they often require space e.g. on the display. To facilitate each grip, the device comprises several separate keys for the same function. When browsing, wide displays are preferable, wherein they extend even to two housing parts when the devices become smaller. To make the use of the device comfortable, the placement of the keys and the holding positions should be ergonomic. It is problematic to implement control keys for other integrated auxiliary functions and positions in PDA/CMT devices whose size is continuously reduced.
[0007] Other portable foldable electronic devices are shown in EP 0898405 A2, U.S. Pat. No. 5,923,751 and JP 9305259.
SUMMARY OF THE INVENTION
[0008] The present invention provides an improvement to the prior art. The present invention facilitates the use of the device by making its handling possible with the grip of one hand both in the opened and in the closed position. The housing parts of the device can be opened without changing the grip or the orientation of the device.
[0009] The hinge mechanism of the device places the housing parts next to each other, and also the total width of the device can be reduced when the housing parts, placed against each other, are moved thereby partly into the handle-like housing part. The displays are protected between the housing parts. The hinge system can be hidden behind the housing parts and inside the handle part, and it comprises a mechanism which automatically opens and preferably also unfolds the device. By means of the hinge system, the point of revolution of the housing parts can be placed right at the edge of the inner walls, facilitating the implementation of various integrated foldable displays.
[0010] Also in the closed position, the PDA/CMT device is held by the handle part, wherein it is also provided with an electronic display, for example for selecting telephone numbers from a list to be scrolled on the display. A telephone number is selected and a call is started and terminated by using control buttons, a navigation key or the like in the handle part. The earpiece of the phone is placed in the upper part of the opening housing part, and the microphone is placed in the lower part.
[0011] The PDA/CMT device is preferably a flat device comprising two designed and substantially parallel side surfaces. A flat side surface is formed by the outer side of one opening housing part as well as the side surface of the handle part, separated by the hinge seam. The opening housing parts, placed against each other, are located on opposite sides of the device, next to the handle part. The handle part and the other housing parts are preferably stationary in relation to each other when the device is in the closed position.
[0012] The device based on a handle-like housing part which is added to foldable housing parts and in which the keys and other control buttons or the like are placed. The invention is based on the way in which the other housing parts are folded in relation to this handle part. The handle part can be designed for an ergonomic grip. When the control buttons are placed on different sides of the handle part, and a navigation key which is preferably also equipped with a push-button function is placed on the upper corner of the device, the device can be controlled with one grip. The device can be opened with a push-button on the top surface. The same keys can also be used to control the auxiliary functions, such as camera, video and music functions. The keys or the like are placed in such a way that the PDA/CMT functions of the device can be used without changing the grip and preferably in the same way by both the left and the right hand.
[0013] A particular advantage is obtained when the aim is to transmit a video image of the user during a call, wherein the closed device can be easily and quickly opened to answer a video call. By means of an image sensor in the device, it is possible to create images in electrical format. The images can be electronically transferred forward and/or displayed on the display of the device. It is not necessary to release the hand from the handle part, wherein the fingers remain on the keys to secure a quick start and control of the functions. The display of the opened device is available for displaying received images e.g. during a video call.
[0014] The lower part of the handle is designed as a crutch. The device remains opened and vertical when placed on a base, for example on a table, and a video call can be continued by releasing the grip, wherein the hands are released for other use. At the same time, the display and the camera are directed to the user. In this position, the display presents, for different purposes, e.g. an electronic calendar, a web site or an electronic still image photographed with a camera as a screensaver or in a way resembling a frame. The handle part also supports the horizontal device in a tilted position, which makes it easier to read the display.
[0015] According to an embodiment, the mechanism for moving the camera changes the orientation of the image sensor automatically when the device is opened. In one case, the image sensor will automatically follow also the user, e.g. by focusing on a detector fixed on the user. The orientation of the camera can also be changed by programming or manually, e.g. by using a 4-directional navigation key in the handle part. The orientation of images, text and other information on the display can be preferably changed in at least two positions rotated 90° in relation to each other. Thus, the opened device can be used in both the vertical and the horizontal position according to the preference of the user or the alternative which is advantageous in view of the application to be run in the device or in view of the information displayed on the display.
[0016] According to an embodiment, the electronic displays located in the two different housing parts are placed adjacent to each other in the opened device, forming a display area which is as seamless and uniform as possible. The display area is slightly folded, but it is preferably substantially planar. This makes it possible to display larger units than one display at one time. Placed on the side of the displays, also adjacent, are also the stereo speakers of the device, for example on both sides of the displays.
[0017] In an embodiment, the upper part of the handle part is provided with the viewfinder of an electronic camera. In the closed device, the image sensor of the camera is oriented in the same direction as the viewfinder. Taking of an electronic image is controlled by control buttons in the handle part. The display of the handle part is also used as the display for the camera.
[0018] In an embodiment, it is also possible to connect to the device a wirelessly operating headset device comprising one or more earpieces and a headset. The device can be used e.g. as a hands-free device. According to another advantageous embodiment, these are also used for listening to music which is transmitted from the PDA/CMT device in digital format in a wireless manner. The music is stored in the memory means of the device and/or it is transmitted to the device by using a wireless communication network. The functions are controlled by using the above-mentioned keys or buttons in the handle part. The headset device can also be equipped with a control unit comprising e.g. a display and keys. According to an advantageous embodiment, the device is controlled in a wireless manner by means of the headset control unit.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] In the following, the invention will be described in more detail by using as an example an electronic PDA/CMT communication device. In this context, reference is made to the appended drawings, in which:
[0020] FIG. 1 shows an electronic device according to an embodiment of the example, particularly a PDA/CMT device in a closed position and seen from the left hand side,
[0021] FIG. 2 shows the device of FIG. 1 in a closed position and seen from the right hand side,
[0022] FIG. 3 shows the device of FIG. 1 in a semi-open position in a perspective view, seen from the rear left side and sloping downwards, and
[0023] FIG. 4 shows the device of FIG. 1 in an open position in a perspective view, seen from the front left side and sloping downwards, and
[0024] FIG. 5 shows the device of FIG. 1 in an opened horizontal position and seen from the front,
[0025] FIG. 6 shows the device of FIG. 1 in a closed position and seen from above,
[0026] FIG. 7 shows the hinge mechanism for the device of FIG. 1 .
DETAILED DESCRIPTION OF THE INVENTION
[0027] With reference to FIGS. 1 and 2 , a communication device 1 , in the following description also called device 1 , comprises in the use position a horizontal handle-like housing part 2 comprising a substantially even side surface 21 . The housing part 2 is arranged for holding the device 1 in the user's palm. A side surface 22 with a substantially identical shape is located on the opposite side of the housing part 2 , i.e. the handle part 2 , and the device 1 . FIG. 2 also illustrates the user's grip to hold the device 1 . In FIGS. 1 and 2 , the device 1 is shown in a closed position (CMT use position), but the device 1 is held in a corresponding manner when it is in its opened position (PDA use position), as shown in FIG. 4 . A right-handed user has the thumb and the other fingers on the sides 22 and 21 , respectively; a left-handed user vice versa. The forefinger is placed on top of the handle 2 when using the navigation key 3 . The handle part 2 also comprises a side surface 23 between the side surfaces 21 , 22 , placed against the user's palm. The side surface 23 extends transversely across the palm between the thumb and the other fingers, when the device 1 is held in the use position and in a substantially vertical position. In FIG. 2 , the side surface 23 and the longitudinal direction of the device 1 are placed substantially parallel to the forefinger. The side surface 23 is supported by the palm, resting on it, when the palm is directed towards the user's face, sloping upwards. The device 1 is thus horizontal or slightly slanted. The fingers are simultaneously used to support the handle part 2 by pressing the side surfaces 21 and 22 , wherein the swinging of the device 1 is efficiently prevented during the use or the opening.
[0028] To control the functions of the device 1 , the handle part 2 is provided with a set of keys, control buttons, navigation keys or the like within the reach of the fingers. When the device 1 is held as shown in FIG. 2 , the forefinger extends to the upper surface 24 of the handle part 2 and to the edge 25 where a navigation key 3 is placed. Depending on the design of the device 1 , the key 3 can be placed even entirely on the top surface 24 or the side surface 23 , being placed, however, symmetrically between the sides 21 , 23 for both hands, but preferably it is in the corner 25 . The control key 4 is placed underneath the thumb, and in a corresponding position on the side 21 there is a control button 5 within the reach of e.g. the forefinger. The device 1 is supported with the fingers from different sides, when the key 4 or 5 is pressed down, and at the same time, the lower part of the palm is supported to the handle part 2 . The buttons 4 and 5 are placed in the upper part 26 of the handle part 2 . For left- and right-handed use, the navigation key 3 is symmetrically located in relation to the side surfaces 21 and 22 . If the buttons 4 and 5 have different functions, it is possible that their functions can be exchanged for different hands by programming and by means of the control system of the device.
[0029] The lower surface 28 of the lower part 27 of the handle part 2 is designed in such a way that the opened device 1 is supported against its base and remains in the vertical position as shown in FIG. 4 . The device 1 is also supported by the unfolded housing parts 6 and 9 , when the lower part 27 extends downwards substantially on the same level with the housing parts 6 and 9 . The display 8 of the device is thus tilted approximately 10-30° backwards, wherein it is easily readable when the user is sitting at a table. At the same time, the camera to be used during a video call can be better directed towards the user. The mass centre of the device 1 is placed on the front side of the supporting point provided by the lower surface 28 .
[0030] With reference to FIG. 2 , the device comprises a first housing part 6 comprising an outer wall 61 which is simultaneously the side and outer surface of the device 1 . Part of the outer surface of the device 1 is also formed by the side surface 22 . The side surface 22 and the outer wall 61 constitute a substantially even surface which is divided into two halves separated by a longitudinal seam 7 at the hinge. The housing part 6 is on that side of the handle part 2 which is opposite to the side surface 23 . This side is facing the user in the opened position of the device 1 , as shown in FIG. 5 , when the planar electronic display 8 is being viewed. On this side there is also a side surface 28 , as shown in FIG. 4 . In this use position, the palm is facing the viewer, and the handle part 2 is oriented away from the user in a direction which is perpendicular (90° angular difference) to the plane defined by the display 8 . In the presented embodiment, an electronic display 81 placed on the inner wall 62 of the housing part 6 and an electronic display 82 placed on the inner wall 92 of the housing part 9 are substantially parallel, when the device 1 is fully opened, as shown in FIG. 5 . They are placed as close to each other as possible, to form a uniform planar display area 8 . The displays 81 , 82 and thereby the housing parts 6 , 9 move to the opposite position (I position shown in FIG. 6 ), wherein the angular difference is 0°, and to an adjacent position (T position shown in FIG. 4 ), wherein the angular difference is even 180°, varying for example between 165° and 180°. The handle part 2 is placed at the hinge at the seam between the housing parts 6 , 9 . In the opposite position, the housing parts 6 , 9 are parallel with the handle part 2 (0° angular difference).
[0031] The device 1 comprises a corresponding second housing part 9 comprising an outer wall 91 which simultaneously constitutes the side and outer surface of the device 1 . Part of the outer surface of the device 1 is also formed by the side surface 21 . The side surface 21 and the outer wall 91 constitute a substantially even surface which is divided into two halves separated by a longitudinal seam 10 at the hinge. In the closed position, the inner walls 62 , 92 are placed against each other, close to and facing each other, wherein the displays 81 , 92 are simultaneously folded together. The displays 81 , 82 and the inner walls 62 and 92 are protected between the housing parts 6 , 9 . Separately, the displays 81 , 82 are substantially rectangular, and when combined by placing their long edges adjacent to each other, they constitute a foldable, almost quadratic display 8 . In one embodiment, the angular position of at least one of the housing parts in relation to the other housing part can be adjusted, e.g. to an angular difference between 0° and 15°. This makes the use easier in the position of FIG. 5 , wherein the display 82 represents a QWERTY keyboard and the display 81 displays the text written. Thus at least the display 82 is a touch screen. The device 1 can be readily opened in this angular position, from which it can be moved to the fully opened position shown in FIG. 5 (0° angular difference). The longitudinal edges of the housing parts 2 and 9 are supported against a base to make it easier to write.
[0032] As shown in FIG. 2 , the upper part 26 of the handle part 2 is provided with an electronic display 11 which is used in the CMT mode for displaying data and information known from mobile phones. These include e.g. text messages, menus for phone settings, the number of an incoming call, the selected phone number, or a phone number list which is browsed. For the CMT mode, the upper part 63 of the housing part 6 is equipped with a set of openings 12 for the phone earpiece which is placed against the user's ear. The earpiece is placed inside the housing 6 and arranged for converting electric signals into audible sound. The lower part 64 of the housing part 6 is equipped with a necessary set of openings 13 for a phone microphone which is placed inside the housing part 6 and arranged for converting the user's speech into an electric signal. The earpiece and the microphone can also be provided in a separate auxiliary device in a wireless radio frequency (RF) or infra-red (IR) connection with the device 1 , wherein the microphone and the earpiece can be easily used also in the opened position and in the PDA mode. In particular, Bluetooth™ wireless technology, which is known as such and is suitable for short-range communication, is applied in the implementation.
[0033] Selections from a menu or a list are made by using the button 4 or 5 . For example, the button 4 corresponds to the SEND button of a phone (starting a call, answering a call), and the button 5 corresponds to the END button of a phone (terminating a call). Alternatively, the menus are browsed and a telephone number is selected with the navigation key 3 , which can be rocked at least forward and backward (corresponding to ARROW UP and ARROW DOWN keys). Thus, the key 3 rocks in the direction of the upper surface 24 and the side surface 23 . To make and/or confirm a selection, the key 3 can also be pressed down by a finger (corresponding to the MENU key of a phone). Text can be written by the key 3 or the like by first selecting the write mode and then browsing the letters. A letter is selected by the button function of the key 3 (alternatively by the key 4 and/or 5 ), as also terminating or sending a text message.
[0034] An advantageous embodiment of the device 1 of FIG. 2 comprises an optical lense arrangement 14 which extends through the handle part 2 and is the viewfinder of the electronic camera. The viewfinder 14 is arranged at the upper edge of the side surface 22 , and it is oriented away from the user in a direction which is substantially perpendicular to the side surface 21 . Alternatively, the view is displayed on the display 11 which is preferably a liquid crystal display (LCD) known as such. The view can be obtained as an image from the image sensor of the camera, converting the optical image to electric signals. The image sensor is for example a charge coupled device (CCD) known as such. On the basis of the view, the camera is focused to its object to take a still or video image. The image is stored in digital format in the memory means of the device 1 , and it can also be transmitted further in a wireless manner in the CMT and PDA modes. Menus and symbols related to the function of the camera, such as dates and image management, are displayed on the display 11 . The button of the key 3 or the control button 4 (or control button 5 ) is used as a release button, and the menus are controlled e.g. by the key 3 .
[0035] According to an advantageous embodiment, the device 1 is used for listening music stored in digital format in the memory means. Furthermore, music signals can be directed to the separate headset device described above. The necessary memory means as well as the means for controlling the functions are alternatively placed in a separate headset control unit. The electric music signals are transferred by means of the device 1 from a communication network to the control unit. On the inner walls 62 , 92 , the device 1 is also provided with sets of openings 16 , 17 for stereo speakers. The speakers are inside the housing parts 6 , 9 . The music functions can be alternatively controlled in the closed position by means of the display 11 and the keys 3 , 4 and 5 . If the device 1 comprises several different functional modes, e.g. PDA, CMT, camera and player modes, the default mode is the CMT mode for receiving calls. The display 11 thus displays a menu for selecting the other modes. In each mode, the functions of the keys and the like are determined according to the selected mode. According to the invention, in the different modes, the device 1 can still be used without changing or releasing the grip of one hand, as well as by controlling it with the control buttons 4 , 5 and the navigation key 3 .
[0036] The buttons 4 and 5 are dome-like film keys which click when pressed down and return up automatically. Preferably, the same film covers both the key 4 (or key 5 ) and the side surface 22 (or side surface 21 ), forming a seamless side surface. The button, designed as a bulge with the size of a fingertip, is placed in a low recess in the side surface. Preferably, also the button function of the key 3 clicks and returns up automatically. The click gives the user a clear feel of operation of the key. For versatile menu functions and for controlling the cursor moving on the display, the key 3 rocks in 2 to 8 different directions (up and down, preferably also left and right in the direction of the side surfaces). Corresponding to each direction or pressing, the key 3 gives a continuous or short electric signal for controlling the device 1 . The key 3 is for example round and fitted in a cradle formed in the handle part 2 . Alternatively, the key 3 is a roll, disc or ball which can be rotated in at least two directions and which also allows pressing down. The rotation axis of the roll is substantially perpendicular to the side surfaces 21 , 22 .
[0037] To facilitate the use, the device 1 is automatically opened by a button 15 which is fitted in a nest formed on the upper surface 24 , as shown in FIG. 6 . According to one embodiment, the button 15 is a mechanically operated locking device triggering a spring-actuated hinge mechanism. Thus, the grip does not need to be released, opening by one hand is possible, and the device 1 is quickly opened to the position of FIG. 4 or 5 , for example for a video call. Thus, the camera is also available, and menus displayed on the touch screen 8 can be browsed by one hand.
[0038] When the device 1 is opened, the housing parts 6 , 9 first move away from the handle part 2 , in the position of FIG. 6 upwards, after which they can be opened as shown in FIG. 3 . In FIG. 6 , the transfer movement and the intermediate position of the housing parts 6 , 9 are shown with a broken line A. From FIGS. 1 and 5 , it is seen that the width of the inner wall 92 , corresponding to the width of the inner wall 62 , is greater than the width of the outer wall 91 , which corresponds to the width of the outer wall 62 . The housing parts 6 , 9 are moved this difference into the handle part 2 , wherein the total width of the closed device 1 is reduced, in the presented embodiment by about 10%. FIG. 3 shows side edge 93 placed lower than side edge 91 , and the edge 94 therebetween, as well as an equal edge 20 in the handle part 2 . The edges 94 and 20 are placed against each other and form a narrow seam 10 according to FIG. 1 . The hinge system on the wall edge 93 is not visible in FIG. 3 . The housing part 6 is provided with corresponding structures. The housing parts 6 , 9 are supported against the inner parts of the handle part 2 and against each other, to prevent folding.
[0039] In one embodiment, the housing parts 6 , 9 are glided out and unfolded by means of force effects of springs under tension. The device is closed by gripping the parts 6 and 9 by one hand, folding them against each other and pressing them inside the handle part 2 . The grip of the other hand still corresponds to that shown in FIG. 2 . In the closed position, the handle part and the housing parts constitute an integrated locked structure which cannot be bent. In the opened-position, the device 1 remains by itself in the position shown for example in FIG. 4 .
[0040] According to one embodiment of the FIGS. 3 and 4 , a camera arm 18 for an image sensor is provided on the surface 29 of the upper part 26 in the handle 2 . The horizontal camera arm 18 is placed between the housing parts 6 , 9 , and it has a set of openings 19 for the sensor lense arrangement. In the closed position, the sensor is oriented in the same direction as the viewfinder 14 . The camera arm 18 is rotatable around its longitudinal axis downwards and in the opposite direction in a sector of at least 180°. The axis of rotation is substantially perpendicular to the side 29 and the walls 62 , 92 in the opened position of FIG. 4 . As the camera arm 18 can also be turned at least 90° upwards as shown in FIG. 5 , the camera can be directed to a wide area, if the device 1 is supported stationary on its base. The axis of rotation is perpendicular to the sides 21 , 22 . To the position of FIG. 5 , the camera arm 18 is bent or placed by means of an arch-like slide rail, at the end of which the camera arm 18 is fixed. Alternatively, the camera arm 18 is placed in the housing part 6 , by the right window 32 and parallel with the wall 62 . The set of openings is thus oriented towards the user in a direction which is substantially perpendicular to the surface 62 , wherein in the closed position, the camera is oriented in the direction of the viewfinder without moving the camera arm. The arm 18 can also be provided with rotation around its longitudinal axis to direct the camera downwards and upwards.
[0041] The camera arm 18 is placed in the position of FIGS. 1 and 5 preferably automatically by means of an electrical and/or mechanical mechanism. Preferably, the position can also be controlled with the navigation key 3 . An image obtained from the image sensor can be preferably displayed on the display 81 and/or 82 , on the basis of which image the orientation of the camera can be checked. As the orientation of the information displayed on the display 8 can be exchanged, the device 1 can be used in the positions of both FIG. 4 and FIG. 5 . In the position of FIG. 5 , the device 1 has a lower gradient angle, about 60° to 80° slanted backwards.
[0042] The arm 18 is left between the housing parts 6 and 9 , wherein their upper edge, extending to the edge on the side of the handle part 2 , is provided with indentations 30 and 31 of equal shape. They are provided with transparent windows 32 , 33 which are equipped with recesses 34 and 35 , in which each the arm 18 can be fitted in half. The recesses are on the side of the inner walls 62 , 92 and constitute a uniform space. In the closed device 1 , the arm 18 is placed in a shield between the windows 32 , 33 and ready for the camera functions as shown in FIG. 1 .
[0043] FIG. 7 shows, in more detail, a hinge mechanism 36 for the device 1 according to an advantageous embodiment. FIG. 7 only shows the fixing of the housing part 6 and one half of the split handle part 2 . The other half of the handle part has an identical shape in mirror image. The mechanism comprises an ejector mechanism 37 for ejecting the housing parts 6 , 9 and the hinge system out of the handle part 2 , an unfolding mechanism 38 to assist in the opening of the housing parts 6 and 9 , and a hinge system 39 for folding the housing parts 6 , 9 together and in relation to the handle part 2 .
[0044] The ejector mechanism 37 comprises one or more locking clutches 371 and 372 fitted in the handle part 2 . They keep the housing parts 6 , 9 stationary in the closed position and form a counter-force for one or more spring means, for example pressure springs 373 and 374 , which continuously tend to move the housing parts 6 , 9 apart from the handle part 2 . A button 15 is arranged to press the upper clutch 371 (in the upper part of the handle part 2 ) which, by means of rod transmission, also turns the lower clutch 372 (in the lower part of the handle part 2 ). A spring 376 turns the clutches into a locking position.
[0045] The hinge system 39 comprises a hinge beam 391 which is parallel with the longitudinal direction of the handle part 2 . Pushed by the springs 373 , 374 , a beam 391 glides inside the handle part 2 away from the user's palm. In the opposite direction, the beam 391 is glided by hand. The movement is limited by pins 392 and 393 whose ends are placed in grooves 40 , 41 inside the handle part 2 . The grooves are formed in transverse ridges 42 and 43 which are also used as guiding rails and are placed in grooves in the other parts of the mechanism. A hinge beam 394 is fixed at one side to the side wall 65 of the housing part 6 , and it is parallel to the beam 391 . The side surface 65 is placed lower than the parallel side surface 61 . The other side of the beam 394 forms a surface corresponding to the side wall 93 of FIG. 3 in the housing part 6 . The structure is preferably covered to form a uniform side surface and to hide the hinge system.
[0046] A structure corresponding to the beam 394 can be manufactured and integrated in the part 6 . The hinge system comprises a parallel hinge beam for the housing part 9 (not shown in the figure), corresponding to the beam 394 . The beams 391 , 394 are provided with grooves 395 , 396 , 397 and 398 for the ridges 42 , 43 , used as glides. The beam 394 does not bend or move in relation to the housing part 6 , and the beam 391 does not bend in relation to the handle part 2 . The beams 391 , 394 are bent around a joint rotation axis C in such a way that their distance from the rotation axis C remains constant.
[0047] The hinge system 39 comprises at least a glide part 399 a fixed to the upper part of the beam 391 and a glide part 399 b fixed to the lower part of the beam 391 , their upper and lower surfaces being equipped with arch-like glide grooves. The glide parts extend towards the parts 6 , 9 . To the upper part of the beam 394 is fixed a counterpart 399 c extending towards the part 2 and provided with an arch-like neck gliding in the groove of the glide part 399 a . The glide part 399 b and a counterpart 399 d , fixed to the lower part of the beam 394 , function pairwise in a corresponding way. The turning points C′ of the glide parts and the counterparts are arranged to be placed on a joint rotation axis C which is at the level of the inner walls 62 , 92 shown in FIG. 5 and in the seam 83 when the device 1 is folded up. Thus, the housing parts 6 , 9 remain attached to each other, and simultaneously also the displays 81 , 82 are placed adjacent to each other as tightly as possible. The rotation axis C is parallel to the longitudinal axis of the handle part 2 . The opening movement can be limited in such a way that the surface 65 is placed against the ends of the glide parts 399 a , 399 b . To the upper part of the beam 9 is fixed a counterpart 399 e extending towards the part 2 and provided with an arch-like neck gliding in the groove of the glide part 399 a . A counterpart 446 fixed to the upper part of the support beam operates in a corresponding manner. The glide part 399 b and a counterpart 399 f , fixed to the lower part of the hinge beam, function pairwise in a corresponding way. To save space, the pair of counterparts 399 c and 399 e as well as the pair of counterparts 399 d and 399 f are placed on opposite sides of their glide parts.
[0048] The unfolding mechanism 38 comprises arms 382 and 383 arranged on a joint longitudinal shaft journal 381 and extending towards the parts 6 , 9 . The pin 381 and the arms 382 , 383 are allowed to move in the transverse direction, towards the parts 6 , 9 in relation to the beam 391 . The arms 383 and 382 are fixed to the beam 394 and to the hinge beam of the housing part 9 by means of a hinge pin 385 and a hinge pin 384 , respectively. The parallel rotation axes in the longitudinal direction of the hinge pins 384 , 385 are placed on opposite sides of the axis C, and each rotation axis on the side of the housing part to which also the hinge pin is fixed. The rotation axes are slightly closer to the part 2 than the axis C. The pin 381 is also provided with a tensioned torsional spring 388 which is continuously effective between the arms 382 , 383 and tends to turn them around the pin 381 towards each other and to be parallel. Thus, a torque force is simultaneously produced, tending to turn the hinge pins 384 , 385 towards each other around the rotation axis C. The hinge pins 384 , 385 are turned so that the direction of their rotation axes is maintained. This, in turn, produces a torque effective on the housing parts 6 , 9 to make them open when ejected, wherein when they are pushed in, the grooves 395 , 396 are supported to the ridges 42 , 43 of the housing part 2 . When turned, the distances between the rotation axis of the hinge pin and the axis C on one hand and between the rotation axis of the hinge pin and the pin 381 on the other hand remain constant, with the result that the position of the pin 381 in relation to the beam and the handle part 2 will vary. Therefore, the pin and the arms are fitted in a movable manner in a nest in the middle part of the beam 391 . Further, the ends of the pin 381 are provided with fitting parts 386 and 387 .
[0049] The electrical components of the PDA/CMT device, such as the circuit boards, the transceiver fitted on a circuit board with its electrical circuits and antenna, as well as the control circuits for controlling the displays and the whole device, are arranged in free spaces left between the housing parts. The keys and the control buttons are in an electrical contact with the control circuits. The operation of the whole device is controlled by a control system operating under a control program stored in the memory means and arranged for controlling the above-described device in a desired manner. The design, manufacture and placement of the necessary components as well as the arrangement of the functions can be selected by anyone skilled in the art according to the requirements at the time. In the selection, it is possible to apply technology and methods known as such. The requirements depend on e.g. the different properties of the device, such as camera or music functions, the capacity of the necessary memory means, the connections to other devices, and the network or networks used for wireless communication, such as a GSM mobile communication network based on a cellular network and/or a short-range RF or IR network. The device with its antenna is arranged to operate in a desired, preferably broadband communication network, e.g. to make the transfer of video calls possible.
[0050] The invention has been described above in an application in connection with an advantageous communication device, to which it is particularly well suited, but on the basis of the description, it is obvious for anyone skilled in the art to apply the invention also in connection with other electronic devices within the scope of the appended claims. The device can naturally be also used with other alternative hand grips and in other positions. The presented grip and use position thus provide an example of a preferred way of holding the device of the invention, wherein the keys of the handle part are placed in such a way that at least this grip and the use of several different functions would be possible and easy.
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A hinge mechanism for a portable, foldable electronic device comprising two or more positions and comprising at least three housing parts foldable in relation to each other, wherein the hinge mechanism comprises: a hinge system adapted to couple a first housing part to a second housing part, to fold the first and the second housing parts in relation to each other, and to couple the first and the second housing parts to a third housing part in a foldable manner; and an ejector mechanism adapted for moving said hinge system away from the third housing part.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a rear view mirror for motor vehicles, in particular for commercial vehicles, comprising a housing, a mirror glass support supported by means of a pivot joint disposed in the housing to be pivotable relative to the housing, and a mirror glass disposed on the mirror glass support.
2. Background Art
A rear view mirror of the generic type is known from U.S. Pat. No. 3,609,014. In this case, a pivot bearing in the form of an articulation ball fixed to the housing is disposed in the housing of the mirror, a substantially plate-shaped mirror glass support pivotally lodging on the articulation ball by means of a corresponding universal ball joint. A mirror glass is fixed on the mirror glass support and is adjustable by pivoting the mirror glass support relative to the housing.
In the prior art rear view mirror, a servomotor is provided between the mirror glass support and the housing, coupled to the mirror glass support by way of a spindle drive, which ensures a remote controlled pivotal adjustment of the mirror glass support and consequently of the mirror glass in relation to the housing.
In this prior art rear view mirror it is of disadvantage that the servomotor is disposed deep inside the housing between the latter's rear and the mirror glass support. As a result, the mounting of the servomotor is difficult and the rear view mirror offers little in terms of convenience of repair, for instance in the case of a defect of the servomotor, since the entire mirror glass support must be detached, which is accompanied by the release of the pivot joint union and the spindle drive coupling.
Further, the construction disclosed in the afore-mentioned U.S. patent is not fit to be used as a simple version without the servomotor. For, as a result of its structure, the pivot joint is comparatively unstable so that the spindle drive coupled with the servomotor is needed for additional stabilization of the mirror glass support.
SUMMARY OF THE INVENTION
It is the object of the invention to further develop a rear view mirror of the generic type such that servomotors are particularly easy to mount or to retrofit and the rear view mirror is convenient to repair.
This object is attained in that the mirror glass support is a hollow defining an installation chamber, into which at least one servomotor is installable for the remote-controlled pivotal adjustment of the mirror glass support and thus of the mirror glass in relation to the housing. The mirror glass support being embodied as a hollow, this provides for a particularly easily accessible installation chamber of exposed arrangement for the accommodation of servomotors, which, in keeping with the object according to the invention, ensures the convenience of mounting and repair of the rear view mirror according to the invention. Moreover, this design offers the prerequisites for the rear view mirror according to the invention to be realized, in the way of a unit assembly system, as a manually adjustable mirror by omitting the servomotors in a simple version, or as a remote-controlled adjustable mirror by placing servomotors in the installation chamber of the mirror glass support in a luxury version.
Further features, details and advantages of the invention will become apparent from the sub-claims and the ensuing description of examples of embodiment of the subject matter of the invention taken in conjunction with the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a lateral view of a first embodiment of a rear view mirror according to the invention,
FIG. 2 is a view of the mirror from the direction of the arrow II in accordance with FIG. 1,
FIG. 3 is a horizontal section through the mirror along the section line III--III in accordance with FIG. 1,
FIG. 4 is a horizontal section, analogous to FIG. 3, of a simple version without servomotors, of the rear view mirror,
FIG. 5 is a vertical longitudinal section through a second embodiment of a rear view mirror,
FIG. 6 is a horizontal section of the mirror along the section line VI--VI in accordance with FIG. 5,
FIG. 7 is a horizontal longitudinal section through a third embodiment of a rear view mirror, and
FIG. 8 is a horizontal section of the mirror along the section line VIII--VIII in accordance with FIG. 7.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The three embodiments of a rear view mirror according to the invention shown in FIGS. 1 to 8 have a housing 1 (FIG. 1 to 4) and 1' (FIG. 5 to 8), respectively, the exterior of which presents the aerodynamically rounded pan shape usual with such mirrors. A pivot joint 2 in the form of a so-called universal joint is disposed about centrally in the housing 1, 1', a mirror glass support 3 (FIGS. 1 to 4) or Y (FIG. 5, 6) or Y' (FIG. 7, 8), respectively, being arranged on the pivot joint 2 to pivot about two main pivot axes 4, 5 (FIG. 2). The mirror glass supports 3, 3', 3" are disposed on the plane of the open side 6 of the housing 1, 1'. They are configured as hollow pans, the mirror glass 7 being fixed in the vicinity of their open side 6. In the example of embodiment according to FIGS. 1 to 4, the mirror glass 7 is caught by an encircling narrow annular projection 8 projecting inwardly from the mirror glass support edge 10 that defines the open side 9 of the mirror glass support 3. On its rear the mirror glass 7 has a heating foil 11 glued on, which is supplied with current by electric leads 12.
On a plane 13 extending in parallel to the mirror glass plane, the mirror glass support 3 according to FIG. 3 and 4 is divided into a base member 14 and a frame member 15 placed thereon. As outlined--the frame member 15 carries the mirror glass 7 in the vicinity of its open side 9. The base member 14 is united with the frame member 15 by means of a locking 16 formed by complementary locking recesses and projections of the base member 14 and the frame member 15. Supporting webs 18 supporting the rear 17 of the mirror glass 7 extend from the base member 14 towards the rear 17 of the mirror glass 7. Thus, the mirror glass 7 is retained in a stable position between the annular projection 8 and the supporting webs 18.
In the example of embodiment shown in FIGS. 5 and 6, the mirror glass support 3' is made in one piece, the mirror glass 7 being fixed in the open side of the mirror glass support 3' by a retaining ring 19 slipped on to the edge 10' where it is appropriately fixed. The retaining ring 19 again has an annular projection 8' bent inwards and towards the mirror glass 7 and retaining the mirror glass 7. The rear 17 of the mirror glass 7 is again supported by supporting webs 18' integrally molded on the base 20 of the mirror glass support 3'.
In the example of embodiment shown in FIGS. 7 and 8, the pan-shaped mirror glass support Y' made in one piece only takes about half the height of the mirror glass 7 and about 2/3 of the latter's width. The fastening of the mirror glass 7 on the open side 9 of the mirror glass support 3" is made by a holding plate 21 on to which the rear 17 of the mirror glass 7 is glued. For joining the holding plate 21 to the mirror glass support 3", complementary projections 22, 23 are provided on the open side 9 of the mirror glass support 3" and on the rear of the holding plate 21, respectively, producing a so-called union of clamping engagement as it is the subject matter of U.S. patent application Ser. No. 08/245,952. Reference is made to this application so as to avoid unnecessary explanations.
Along its edge the holding plate 21 has a continuous collar 24 integrally molded thereon, by means of which the gap between the mirror glass 7 and the housing 1' is restricted to the dimension necessary for the mirror glass to pivot unimpeded in the housing 1'. In the examples of embodiment according to FIGS. 1 to 4 and 5, 6, respectively, this function is fulfilled by the side wall of the pan-shaped mirror glass support 2 or 3', respectively.
By reason of its design as a pan the mirror glass support 3, 3', 3" defines an installation chamber 25 into which to insert servomotors 26, 27. These servomotors 26, 27 usually are electric motors screwed on bearing sleeves 28 integrally molded on the base 20 of the mirror glass support 3, 3', 3". The servomotors 26, 27 are stationary on the mirror glass support 3, 3', 3".
The movable positioning member of the servomotors 26, 27 is formed by a crank disc 29 to which a connecting rod 31 is articulated by way of a crank joint 30. Each connecting rod 31 is guided within one of the bearing sleeves 32, 33 (FIG. 2) to be displaceable in the longitudinal direction and rotatable about the longitudinal axis of the latter. The two guide sleeves 32, 33 are integrally molded on a substantially triangular coupling plate 34, which is tightly united with the components, fixed to the housing 1, of the pivot joint 2 in a manner still to be specified. Consequently, the coupling plate 34 is supported, fixed to the housing 1.
On the one hand the pivot joint 2 designed as a spherical universal joint consists of a spherical bearing ring 35 formed integrally with the base member 14 and the base 20 of the mirror glass support 3 and 3', 3", respectively. The bearing ring 35 is clamped by frictional locking between a spherical bearing member 36 fixed to the housing 1 and located on the rear of the mirror glass support 3, 3', 3" and a spherical bearing cover on that side of the mirror glass support 3, 3', 3" turned towards the mirror glass 7. By way of a compression spring 38 the bearing cover 37 supports itself on an abutment cover 39 placed on a spacing sleeve 40. The latter projects centrally from the bearing member 36 and, by some clearance, passes through the inside opening 41 of the bearing ring 35 as well as the bearing cover 37. The abutment Cover 39 together with the coupling plate 34 and the spacing sleeve 40 are tightly screwed together. Consequently, the abutment cover 39 cooperates with the fastener 42 to form a support member, fixed to the housing 1, for the coupling plate 34.
In the example of embodiment according to FIGS. 3 and 4, the arrangement, fixed to the housing 1, of the bearing member 36 is realized in that the bearing member 36 is provided with a clamp bearing member 43 molded on integrally and cooperating with a clamp fitting 44. By means of the clamping device comprised of the clamp bearing member 43, the clamp fitting 44 and the fasteners 45, the mirror is clamped on to a holding pipe 46 passing through the housing 1 in the vertical direction and producing the union with the body (not shown) of the vehicle. By way of the fasteners 45 the housing 1 is simultaneously tightly joined to the clamp fitting 44 and thus to the bearing member 36.
In the embodiments according to FIGS. 5, 6 and 7, 8, respectively, the bearing member 36 is an integral part of a support plate 47 having two clamp bearing members 43' integrally molded on each with a corresponding the clamp fittings 44' and the fasteners 45' together form a clamping device for the fastening of the mirror on a mirror holding pipe (not shown in FIGS. 5 to 8). A pan-shaped housing base member 48, of which the continuous side wall 49 confines the volume swept by the pivoting of the mirror glass support 3', 3", is screwed on the support plate 47 from the side turned away from the mirror glass 7. From the rear of the base member 48 turned away from the mirror glass support 3', 3" a cover member 50 is locked on to the housing base member 48 (locking 51 in FIGS. 6, 8).
As can clearly be shown by a comparison of FIGS. 3 and 4, the mirrors shown in FIGS. 1 to 8 are structured such as to be provided with servomotors 26, 27 in the way of a unit assembly system or to be conceived as purely manually adjustable mirrors without these servomotors. If a remote-controlled adjustable luxury mirror is demanded, the servomotors 26, 27 are inserted in the mirror glass support 3, 3', 3" as explained in conjunction with FIGS. 1 to 3 and 5 to 8. In this case, the servomotor 26 serves to pivot the mirror glass support 3, 3', 3" about the vertical main pivot axis 4, whereas the servomotor 27 serves to pivot the mirror glass support 3, 3', 3" about the horizontal main pivot axis 5. Now, if for instance the servomotor 26 is actuated for the crank disc 29 to rotate clockwise, then the connecting rod 31 supports itself on the guide sleeve 32 fixed to the housing 1 so that the mirror glass support 3 is also pivoted clockwise about the vertical main pivot axis 4. To compensate the change of distance between the guide sleeve 32 fixed to the housing 1 and the crank joint 30, the connecting rod 31 moves out of the guide sleeve 32 by the corresponding length.
If the mirror, as a simple version, is only to be pivoted manually, the servomotors 26, 27 only have to be omitted together with the crank disc and the connecting rod and the coupling plate 34. Apart from that the complete structure of the mirror can be maintained. For the assembly of the pivot joint 2, the nut 52 (FIG. 4) only has to be screwed further on the fastener 42 or, respectively, the fastener 42' has to be screwed further into the spacing sleeve 40 (FIG. 5 to 8). Such a manually adjustable mirror can very easily be retrofitted with the servomotors 26, 27.
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A motor vehicle rear view mirror comprising a housing, a mirror glass support supported by a pivot joint disposed in the housing to be pivotable relative to the housing and a mirror glass disposed on the mirror glass support. The mirror glass support defines an installation chamber sized to hold at least one servomotor for the remote-controlled pivotable adjustment of the mirror glass support and thus of the mirror glass relative to the housing.
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[0001] This application claims priority benefits under 35 United States Code, Section 119 (e) of co-pending U.S. Provisional Application No. 60/204,964, filed May 17, 2000, for TwoStage Optical Alignment Device (Attorney's Docket No. CORE-66 PROV).
FIELD OF INVENTION
[0002] This invention relates to alignment of optical components for testing and assembly of optical systems operating outside of the visible light range, and more particularly to the alignment of optical components for infra-red optical systems.
BACKGROUND OF THE INVENTION
[0003] In the manufacture of optical systems, and more particularly fiber optic communications systems, it is essential to provide efficient optical coupling of optical components for testing, and optionally for assembly, purposes. By way of example, manufacture of certain optoelectronic devices for fiberoptic communications systems may require alignment along orthogonal X-Y-Z axes of a first optical element that has an aperture in the form of an opening or a window that is transparent with respect to light with a wavelength outside of the visible light range, e.g., a Fabry-Perot optical filter or a vertical cavity semiconductor laser, with a light beam emanating from a second optical element, e.g., a laser light source or an optical fiber serving as a light input source. More specifically, the two optical elements must be aligned in an X-Y plane and also precisely spaced along a Z axis that is normal to that plane. It is essential that the alignment process be precise, reliable, repeatable and fast.
OBJECTS AND SUMMARY OF THE INVENTION
[0004] The primary object of this invention is to provide an automated apparatus and method for precise three-dimensional optical alignment of optical components during assembly and inspection.
[0005] A more specific object is to provide an automated apparatus and method for three-dimensional optical alignment that employs a two-dimensional visible light machine vision system to assist active alignment of optical components based on the measured optical output at a wavelength of light outside of the visible range.
[0006] A further object is to provide an apparatus and method for aligning optical elements, one of which is a source of an optical beam with a wavelength outside of the visible range, with a 5 micron precision along the axis of the beam (Z axis) and a 0.25 micron precision in a plane perpendicular to the axis of the beam (the X-Y plane).
[0007] These objects are achieved by providing a motorized X-Y-Z motion apparatus having a movable support member for supporting a first optical element having an aperture for transmittal of light with a wave-length outside of the visible light spectrum and motion-translating means for selectively moving that support member along mutually orthogonal X, Y and Z axes, means for supporting a second optical element in the form of a source of a light beam having a wavelength outside of the visible range in a fixed position relative to the motorized motion apparatus with that light beam directed in the Z-axis direction at the aperture of the first optical element, a visible light vision system using visible light imaging for determining (a) the position of the first optical element relative to said visible light vision system in the X-Y plane and (b) the sharpness of the image of the first element as detected by the visible light vision system, an optical measurement device responsive to the beam for measuring a power-related value of the beam, and a motion control system for causing the motion-translating means to (a) move the movable support member in the X-axis, Y-axis and Z-axis directions as required to achieve X-axis and Y-axis alignment of said first optical element with said visible light vision system and maximize the sharpness of the image, and (b) subsequently move said movable support member first in the Z-axis direction and then in the X-axis and Y-axis directions as required to maximize a power-related value of said beam as measured by said optical measurement device. Other features and advantages of the invention are set forth in or rendered obvious by the following detailed description of the invention which is to be considered together with the accompanying drawing.
THE DRAWING
[0008] The drawing schematically illustrates a system embodying the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0009] The system shown in the drawing comprises a motorized X-Y-Z motion apparatus 2 that comprises three stages 4 , 6 and 8 , which are coupled together and carry a platform 10 . Stage 4 is movable bidirectionally in the X-axis direction; stage 6 is movable bidirectionally in the Y axis direction at a right angle to the X axis, and the third stage 8 is movable bidirectionally vertically along the Z axis orthogonal to the X and Y axes. The platform 10 serves as a support for a first optical element 12 which is to be aligned. The platform 10 has an opening 14 to permit light to be transmitted to the optical element 12 from a second optical element 16 that is mounted on a support 18 that is fixed in relation to the motion apparatus 2 and also a visible light vision system 20 . Although not shown, it is to be understood that means are provided for securing optical elements 12 and 16 against movement relative to platform 10 and support 18 respectively. The fixed relationship between motion apparatus 2 , support 18 and vision system 20 is represented schematically in the drawing by the intersecting lines B and S.
[0010] The visible light vision system 20 comprises an electronic camera 22 , preferably a digital camera, that employs a CCD, MOS or another suitable semiconductor imaging device (not shown). A light source 24 is coupled so as to supply visible light to a housing 28 which is mechanically and optically connected to camera 22 and a second housing 30 , e.g., by barrel members 32 and 34 . Housing 28 contains an optical system comprising a 50/50 beam splitter schematically represented at 36 which (a) directs the visible light from source 24 so as to illuminate optical element 12 and (b) transmits the visible light reflected by element 12 to camera 22 , whereby a visible image of that optical element may be received by the imaging device of camera 22 . In the drawing the visible light path is represented by the solid line arrows. For convenience of illustration, the portion of the visible light path running from beam splitter 36 to optical element 12 is offset from that portion of the light path that extends from optical element 12 to the camera.
[0011] Housing 30 contains a dichroic mirror 40 that is disposed at a 45° angle to the optical axis of camera 22 . Mounted in an extension 42 of housing 30 is an objective lens represented schematically at 44 . Housing 30 has a side opening and connected to that side opening is a tubular barrel 46 which in turn is coupled to an optical measurement device represented schematically at 48 . The optical measuring device may take various forms; preferably it is an optical power meter or an optical spectrum analyzer. In the case where the optical elements are to be aligned for infra-red light testing and assembly, the optical measurement device essentially comprises an IR detector.
[0012] Although not shown, it is to be understood that optical element 12 has an internal aperture in the form of an opening or a window that is transparent to light having a wavelength outside of the visible light range, with the element 12 being, for example, a Fabry-Perot optical filter or a vertical cavity semiconductor laser. The element 16 , which may be a semiconductor laser or an input optical fiber serving as a source of optical power outside of the visible range, is mounted on the support 18 so as to be substantially centered with respect to the optical axis of the visible light vision system, so as to direct a beam of light outside of the visible range through opening 14 and the aperture of optical element 12 . The dichroic mirror 40 is adapted to pass visible light from the visible light vision system through the objective 44 to effect imaging of optical element 12 , and to reflect the non-visible light beam from source 16 to the optical measuring device 48 . The path followed by the non-visible light beam from source 16 is indicated by the broken line arrow.
[0013] The visible light vision system is adapted to determine the X-Y position of optical element 12 in relation to the vision system by measuring the degree of X-Y plane registration of the image of said optical element with the camera's imaging device, and also is adapted to produce a first output error signal representative of the extent of X-axis and Y-axis misalignment of said first optical element in relation to that imaging device. The vision system is also adapted to determine the sharpness of the image seen by the camera by measuring the intensity gradient of the image, e.g., the contrast, at the periphery of the image, and to produce a second signal that varies as a function of image sharpness. Those signals are applied sequentially to a programmable motion control system 50 . The first signal causes the motor control system to activate the X axis and Y axis stages 4 and 6 so as to move platform 10 in the X-axis and Y-axis directions to the extent required to place the element 12 in alignment with the vision system in the X-Y plane. The second signal produced by the vision system causes control system 50 to effect operation of the Z-axis stage 8 whereby to shift the position of optical element 12 along the Z axis, i.e., along the optical axis of the visible light vision system, until the vision system has determined that the image received by the camera has achieve maximum sharpness. In effect, the vision system and the motion control system coact to provide automatic focusing, with the Z axis stage moving until the maximum intensity gradient is observed at the edges of the image seen by the camera.
[0014] When a light beam with a wavelength outside of the visible range is transmitted by optical element 16 though optical element 12 , it passes through and is transmitted by objective 44 onto mirror 40 , which reflects it to optical measurement device 48 . The optical measurement device 48 is adapted to measure a selected power-related value of the light beam reflected by dichroic mirror 40 . For example, it may be adapted to measure the overall intensity of the beam, or the intensity of a selected mode or the intensity differential between two modes. The optical measurement device produces a feedback control signal which is applied to the motion control system. The latter responds to that signal by causing stages 4 and 6 to effect X-Y plane movement of platform 10 and thereby optical element 12 in a direction to maximize the measured power-related value of the light beam from optical element 16 . That value is at its maximum only when the aperture of optical element 12 has been aligned with the non-visible light beam from optical element 16 .
[0015] In the preferred embodiment of this invention, the motion control system is programmed so as to automatically cause the motorized Z-axis stage 8 to move the optical element 12 a predetermined amount along the Z axis after the three-axis visible light alignment has been accomplished and before it causes the X and Y stages 4 and 6 to move to maximize the power-related value of the non-visible light beam measured by optical measurement device. This automatic Z-axis movement, which is identified herein as “offset”, is for the purpose of (a) compensating for mechanical misalignment of motion apparatus 2 , vision system 20 and the fixed position of optical element 16 as determined by support 18 , and (b) correcting for optical aberration resulting from the fact that non-visible and visible light behave differently in passing through the objective. The amount of offset is determined by prior measurements.
[0016] In the preferred embodiment of the invention, the motion control system 50 is programmed to achieve alignment by automatically executing a method comprising the following steps:
[0017] 1. Vision system 20 measures the position of optical element 12 in the X-Y plane and if the image is not in registration with predetermined X-Y coordinates of the imaging device of camera 22 , the vision system of the camera delivers a control signal to the motion control system which in turn causes movement of X stage 4 and/or Y stage 6 so as to move element 12 into alignment with the visible light vision system.
[0018] 2. Next, the visible light vision system measures the sharpness of the image of optical element 12 and delivers a signal to the motion control system which causes it to operate the Z axis stage of the motion apparatus so as to shift optical element 12 incrementally along the Z axis until the image focused on the image plane of camera 22 has achieved maximum sharpness.
[0019] 3. Next, motion control system 50 automatically activates the Z axis stage so as to cause the optical element 12 to shift a predetermined amount in a predetermined direction for the purpose of compensating for mechanical misalignments and correcting for chromatic aberration.
[0020] 4. Thereafter the optical element 16 is caused to transmit a non-visible light beam through optical element 12 to mirror 40 , and optical measurement device 48 measures the intensity of that beam as reflected by mirror 40 and generates control signals which are applied to the motion control system 50 so as to cause the X-axis stage 4 and/or the Y-axis stage 6 to move in a direction and by an amount sufficient to maximize the power related value measured by the optical measurement device 48 . As noted above, the optical measurement device 48 may measure various power related values of the non-visible light beam, but preferably it is programmed to measure the maximum optical power of the reflected light beam and/or the maximum side mode suppression of that light.
[0021] Thereafter the optical element 12 may be fixed in an optical assembly or subjected to other optical measurements.
[0022] It is to be noted that the invention need not be practiced exactly as hereinabove described and illustrated. For one thing, the invention may be modified by providing more than two optical elements in the system to be aligned. Additionally or alternatively, there may be more than one three-dimensional moving mechanism 2 to move more than one optical component of the system under alignment. Furthermore, it is contemplated that the three-dimensional mechanism 2 can be arranged differently than as illustrated and described. For example, the three-dimensional motion apparatus or device can be arranged so that one axis of motion can move one optical element of the optical system under alignment, together with the vision system and the optical measurement device, and a dual axis motion system can be used to move the second optical element. Further with respect to the invention, it should be noted that the visible light vision system and the optical measurement device may move relative to one another so long as their mutual position is known with sufficient accuracy. Also the invention may be adapted for use with a non-infra-red light source as the optical element 16 . The present invention can also be used if more precise Z-axis alignment is required. In that case, an another step is added to the sequence of steps described hereinabove. During this step the Z-axis position of optical element 12 will be further optimized to obtain a maximum for the optical power-related value measured by optical measurement device 48 .
[0023] In addition to the advantages rendered obvious by the foregoing description, it should be noted that the two-stage alignment process of the present invention makes it possible to obtain precise alignment even though the optical element represented at 12 may not have a precise peripheral configuration or a peripheral configuration that is exactly concentric with its aperture, since the active non-visible light X-Y alignment steps assure that the non-visible light beam is accurately centered with respect to that aperture. Moreover use of a vision system for three-dimensional alignment as herein described allows for faster alignment. The invention also makes possible a reduction in the cost of alignment equipment by reducing the stroke and velocity requirements needed from the super precision-actuators used for fine active alignment. The invention also reduces the cost and complexity of the alignment equipment by promoting the use of conventional two-dimensional machine vision systems for three-dimensional alignment. It also promotes the use of a visible light machine vision system to perform alignment of optical systems with a wavelength of light outside a visible light. A further advantage is that a visible light vision system as described is well known to persons skilled in the art, as are motion control systems and three-axis motion systems. Another advantage is that motion apparatus of the kind contemplated by the invention is commercially available. Moreover, the individual X, Y and Z axis stages are available for separate mounting. Thus, for example, stages 4 , 6 and 8 may be like the linear motor driven stages sold by Anorad Corporation of Hauppauge, N.Y. and Aerotech Corporation of Pittsburgh, Pa.
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A method and an automated apparatus for three-dimensional optical alignment of optical components for testing or assembly purposes comprise use of a visible light vision system to assist active alignment of optical components based on the measured optical output at a wavelength of light outside of the visible range.
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BACKGROUND OF THE INVENTION
This invention relates to a drive system employing two or more torque transmitting devices, and particular it relates to an improved clutch or brake arrangement for providing load sharing between two or more motors driving a common load.
Canadian Pat. No. 934,679 issued Oct. 2, 1973 to Eastcott et al, describes a clutch or brake inching scheme. This scheme has been found to be practical and has enjoyed acceptance in the mining industry for synchronous motor driven grinding mill drives where load sharing or angle matching between partner driving motors is essential. If the load is not shared equally between the driving motors, one motor would be overloaded while the other motor would be underloaded.
The scheme described in the aforementioned Canadian Pat. No. 934,679 pulses the clutches for slightly different durations, that is, the clutch connected with the motor having the greater load is pulsed for a slightly longer time than is the clutch connected with the motor having the lesser load. The term "pulse" or "pulsing" refers to a brief reduction of the fluid pressure in a pressure actuated clutch so that the pressure in the clutch drops briefly below the load line permitting the clutch to slip. This unequal pulsing tends to cause the overloaded motor to shed some of its load while the underloaded motor takes on more load.
It should be remembered that the rotational adjustments are very small. For example, a 6000 HP, 180 RPM synchronous motor operated from a 60 Hz supply will have a 100% load change over a load angle, measured at the clutch, of 1.4 degrees. This is only 84 minutes of arc. If acceptable load sharing between motors was determined to be plus or minus 4%, then this is equivalent to only 3.36 minutes of arc (or 0.056 degrees). This is a very small angular amount.
One of the difficulties of achieving good load sharing is that the pulse of air (that is the reduced pressure pulse) does not immediately drop from a stable operating clutch air pressure to the desired reduced air pressure which permits clutch slipping, nor does it immediately return to normal operating pressure at the end of the pulse. The present invention seeks to improve the form of the pulse.
SUMMARY OF THE INVENTION
With the trend towards larger drives, it has become necessary to use with each driving motor two or more fluid clutches in parallel to transmit the larger motor torques. The present invention makes use of the two (or more) clutches which are in parallel in the drive chain.
Thus there is, for each driving motor, a clutch arrangement which has a clutch drum with two or more sets of clutch shoes which may be pressed outwardly against the drum. A shaft which extends within the drum carries an assembly for supporting each set of shoes and an inflatable tube for each set of shoes. When a tube is inflated by the injection of a fluid, such as, for example, air, the tube expands and presses the respective shoes against the clutch drum.
Each tube is connected by a respective fluid line to a bore extending axially within the shaft, and the bore is connected through a rotary connection and a flexible line to a solenoid operated valve. The valve can switch or change state so that it connects the line which goes to the rotary connection to either a supply of fluid under pressure or to an exhaust port. It is this valve that provides the pulse of reduced pressure for a short time interval to inch the clutch.
In operation the valve connects each tube through the rotary connection, supply lines, etc., to a source of fluid that is maintained at a predetermined operating pressure. When the valve is pulsed, it connects the tubes through the connecting lines, connections and hoses to atmosphere for a short time interval. This time interval, by way of example only, may typically be less than a second. The pressure in each tube falls equally as the fluid exhausts, but because of the volume of fluid which must exhaust and the resistance of the pathway through the lines, connections hoses and valve, the pressure in the tubes falls exponentially to a value beneath the load line pressure at which the clutch slips. When the short time interval is over, the valve reconnects the tubes to the source of fluid under pressure. Then the pressure in the tubes rises exponentially. The fall and subsequent rise of pressure in the tubes forms a downwardly extending curved and pointed locus which is relatively blunt. The present invention, by means of a simple improvement, makes the curve in the region of pressure change, considerably sharper. This improves the dynamic response of the clutch and makes the clutch easier to control.
The improvement is achieved by introducing a controlled restriction into only one of the two or more fluid lines which connect respective flexible tubes to the bore in the shaft. The restriction substantially isolates its respective tube from the remainder of the system insofar as the short interval pulse is concerned. This reduces the volume of fluid which must be exhausted in the short time interval to substantially one half (for a two tube clutch). Because the volume of fluid being dumped is reduced, the dynamic response of the system is improved.
It is therefore an object of the invention to improve the dynamic response of a clutch having two or more expandable tubes in an inched load sharing drive.
It is another object of the invention to provide a fluid operated clutch having two or more operating tubes for pressing shoes in the clutch against a drum, the clutch being for use in an inching arrangement in a load sharing drive, in which the clutch has an improved operating characteristic.
Accordingly there is provided a clutch for use in an inching arrangement in a load sharing drive system, comprising at least a first and a second clutch unit mounted on a driving shaft, each clutch unit having a respective first and second inflatable, flexible tube or actuating cylinder for pressing respective first and second friction shoes outwardly against a drum mounted to a driven shaft, the driving shaft having therein a central bore connected to a supply of fluid at a predetermined operating pressure, a first and a second air line each communicating with the bore and with a respective one of the first and second tubes, and a restriction in the second air line for restricting the flow of the fluid into and out of the second tube whereby the pressure of the fluid in the second tube falls only slightly in response to a pressure reduction in the bore which causes the pressure in the first tube for a short time interval to fall below a load line pressure permitting clutch slipping.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be described with reference to the accompanying drawings, in which:
FIG. 1 is a schematic drawing showing part of a clutch, in section, with an associated fluid supply,
FIGS. 2A and 2B are graphs of clutch pressure plotted against time for an ideal pulse of reduced pressure and for a typical practical pulse of reduced pressure in a prior art clutch, useful in describing the invention, and
FIG. 3 is a graph of clutch pressure plotted against time, showing a comparison between a reduced pressure pulse for a prior art clutch and a clutch according to the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring first to FIG. 1, a clutch 10 is shown having two clutch units 11 and 12. The two clutch units 11 and 12 comprise a dual clutch assembly mounted on a driving shaft 14. Each clutch unit 11 and 12 has a respective heavy flexible, inflatable tube, such as a heavy rubber tube 15 and 16, mounted on it. Each tube 15 and 16 is connected by a respective air line 17 and 18 to central bore 20 in shaft 14. The following description will refer to air, air lines, supply of air under pressure, etc., however it should be noted that other suitable fluids may be used. Respective clutch friction shoes 21 and 22 are mounted radially outwards of tubes 15 and 16. The clutch friction shoes 21 and 22, the tubes 15 and 16, and the clutch units 11 and 12 are all constrained to rotate with shaft 14.
A drum 22 is mounted to a driven shaft or pinion shaft 23. The shafts 14 and 23 are coaxially arranged. In a grinding mill drive which has two driving motors, as described, for example, in the aforementioned Canadian Pat. No. 934,679 there would be two clutches, one for each driving motor. A shaft corresponding to shaft 14 in each clutch would be connected to a respective driving motor, and a shaft corresponding to shaft 23 in each clutch would be connected to a respective pinion. The multiple pinions would be in engagement with a common bull gear on the mill.
Still referring to FIG. 1, the bore 20 is connected through a rotary connection 25 and a flexible hose or line 26 to a valve 27. The valve 27 is connected through line 30 to a source 31 of air maintained at a stable operating pressure. The valve 27 has an exhaust 32 to atmosphere. The valve 27 is a fast acting valve that is operated by a solenoid 28 so that the hose 26 is connected either to line 30 and the source of air under pressure 31 or to exhaust 32.
The operation of the clutch system as described so far is well known. When a clutch 10 is to be inched, that is, when the pressure in tubes 15 and 16 is to be reduced for a short interval to permit the clutch to slip, solenoid 28 operates valve 27 so that hose 26 is connected for a short time interval to exhaust 32. This reduces the pressure in hose 26 and bore 20. Because, in the prior art, the air lines 17 and 18 are equally proportioned and unrestricted, the pressure in bore 20 is communicated equally to tubes 15 and 16. The pressure in tubes 15 and 16 drops equally to a pressure below the load line pressure at which the clutch begins to slip. The solenoid 28 then operates valve 27 to its normal operating position and hose 26 is connected through line 30 to source of air under pressure 31.
Referring now to FIG. 2A, there is shown a graph of air pressure in a clutch plotted against time and this represents an ideal pressure notch 32, that is, it represents an idealized pressure reduction pulse 32. The line 33 represents the normal, stabilized, clutch operating pressure. The broken line 34 represents the clutch load line, that is, it represents a pressure below which the clutch will slip. It will be seen that the idealized pressure notch 32 drops rapidly from the clutch operating pressure 33 to a level well below the load line 34, levels off for a short time interval, and then rises rapidly to the normal clutch operating pressure 33. The time duration of such a pressure reduction notch 32 might, ideally, be of the order of microseconds. While such a pressure reduction notch cannot be achieved, the closer a clutch can approach this notch the better will be the clutch response.
Referring now to FIG. 2B, there is shown another graph of clutch pressure plotted against time, and this graph represents a typical pressure reduction notch such as prior art clutches might provide. Again, line 33 represents normal clutch operating pressure and broken line 34 represents the clutch load line. At time t 1 valve (such as valve 27, FIG. 1) dumps to atmosphere and the pressure in the clutch (such as tubes 15 and 16, FIG. 1) begins to reduce exponentially towards atmospheric pressure. At time t 2 the pressure in the clutch falls past the clutch load line and the clutch begins to slip. At time t 3 the valve recloses and the valve connects the clutch system (such as hose 26, etc.) to a source of air under pressure (such as source 31, FIG. 1). The pressure in the clutch (such as tubes 15 and 16, FIG. 1) begins to build up exponentially. At time t 4 the pressure in the clutch increases past the load line and the clutch stops slipping. At time t 5 the clutch pressure is restored to normal operating pressure. Thus the pressure in the clutch (tubes 15 and 16) is below normal operating pressure from time t 1 to time t 5 , and the clutch slips only between time t 2 and time t 4 . The pressure notch 35 is relatively blunt. The closer the pressure notch can be made to approach the ideal notch (i.e. the sharper the notch can be made), the better will be the response of the clutch.
Referring again to FIG. 1, according to the invention, an adjustable or settable restriction is introduced into air line 18. This restriction is preferably a needle valve 37. The needle valve 37 provides a restriction which reduces the rate of flow of air into and out of tube 16. During normal operation both tubes 15 and 16 will have air at normal clutch operating pressure and will transmit equal torque to drum 22. However, during sudden changes of pressure in bore 20, the needle valve 37 restricts the flow of air into and out of tube 16. Thus, needle valve 37 substantially isolates tube 16 from the very rapid pressure reduction pulses which are used in a load sharing arrangement such as is described in the aforementioned Canadian Pat. No. 934,679. The pressure reduction pulses which are created in bore 20 of shaft 14 are typically less than one second in duration. The volume of air in tube 16 which communicates with bore 20 through needle valve 37 may be made to represent a value equivalent to perhaps a five second time constant. Needle valve 37 thus effectively uncouples clutch unit 12 from responding to fast pressure pulses, but clutch unit 11 which has no similar restriction will be able to respond.
During a fast pressure reduction pulse or notch, the volume of air which must be handled by valve 27 is only slightly greater than that volume concerned with tube 15 since tube 16 is substantially isolated for rapid pressure changes. Because the volume of air that must be dumped to atmosphere and replaced must pass through the flow restricting resistances of air line 17, bore 20, rotary connection 25, hose 26 and valve 27 is considerably reduced, the dynamic response will be improved. With the needle valve 37 in use during a rapid pressure reduction pulse, the clutch unit 11 will provide a greater proportion of the inching or synchronizing function and the clutch unit 12 a very minor portion. The load angle displacement between two driving synchronous motors can be made very small although each clutch may slip a significant amount during a pulse cycle.
Those skilled in the art will appreciate that if a compressible fluid such as air is used to control the clutches from an external valve array, it is impossible to create the ideal narrow vertical sided pressure notch shown in FIG. 2A. In practice the best that can be done, because of fluid compressibility and pipe friction losses, is to create a pressure notch that consists of an exponential decay curve during dumping the clutch tube pressure to atmosphere, followed by an exponential pressure recovery curve when the control valve recloses to stop further movement of the clutch shoes and cause the clutch tube pressure to return to normal operating pressure. This is shown generally in FIG. 2B. Aforementioned Canadian Pat. No. 934,679 teaches that the clutch operation can be improved if the controlling valve open-close pulse cycle is just long enough to cause the pressure in the clutches to fall for only several milliseconds below that precise load line pressure needed to prevent shoe slippage. The shape of the pressure decay and recovery curves above the shoes locked pressure is then irrelevant. Pat. No. 934679 also teaches that with principle of differential pulsing, the net clutch shoe movement effecting the load angle displacement between two partner synchronous motors can be made very small although each clutch may slip a significant amount during a pulse cycle.
The precision of control possible with these systems, if air is used as the controlling medium is restricted by the total volume of each clutch being pulsed. It is only practical to increase the size and dynamic fluid handling capacity of the air valves, piping, rotary connection to the motor shaft, and motor shaft bore up to a certain point. As the clutch tube volumes become larger in size, those skilled in the art will readily appreciate that the pressure notches as seen by the clutch shoes increase in width, or get further away from the ideal narrow vertical sided notch configuration which would produce excellent control.
In accordance with the invention the dynamic response of the inching controls is improved by placing a small restriction in the air connection to one of the two or more clutch tubes connected in parallel. If the size of the restriction is chosen so that the ability of the tube which is fed through them takes perhaps ten times as long to follow pressure fluctuations as its partner clutch element tube without restrictions, then dynamically for very short time pressure notches, the total clutch volume to be pulsed appears to the control system as if it were reduced to almost half. With this improvement alone, the pressure notches in the unrestricted tube tend towards half the full volume clutch width duration which permits better control of the inching process. Between the slow engagement of grinding mill clutches during the acceleration period which may occur over 10 seconds compared to perhaps a 0.5 second full pulsing notch there is excellent discrimination possible by selecting the correct setting of needle valve 37, FIG. 1.
The improvement obtained in the dynamic response of such systems by the introduction of suitable restrictions 37 would at first appear to approach 2:1, but this is not the case. In a two element or dual clutch assembly when one of the tubes is isolated by restrictions from sudden control pressure changes, it must be appreciated that its clutch shoes do not respond to the pressure notch and tend to remain at the original torque level. Those versed in regulating system mathematics will recognize that the restrictions have reduced the mechanical gain of the system to some number approaching one half of its unrestricted value. The magnitude of the pressure changes in the unrestricted clutch to produce slip will then tend to increase to twice their original value, and it would first appear that adding restrictions is a trade off.
Several factors tend to favour the system using a restriction in one or more (but not all) of the clutch air lines. When any fluid is moved rapidly through pipes and fittings, the friction effect degrading pulse width is a function of velocity, particularly in the case of a compressible fluid such as air. In the case of any system using air to control the clutches, it is well known that when the flow rate tries to exceed the speed of sound, it is almost impossible to induce the air to move any faster regardless of the pressure applied. By cutting down the amount of air to be handled during each synchronizing pulse, these non linear resistances to flow become less able to degenerate or widen out the pressure notches as seen by the clutch tubes. Consequently there can be a net gain in performance approaching 30 percent depending entirely on the physical configuration of the valves, piping, and pressure supply.
Referring to FIG. 3, there is shown a graph of clutch pressure plotted against time for a prior art type of clutch and for a clutch according to the invention with a restriction in one of the air lines. The notch or curve 35, representing a short interval pressure reduction in a prior art type of clutch is the same as that depicted in FIG. 2B. Line 33 represents the normal clutch operating pressure, and line 34A represents the clutch load line where a prior art type of clutch begins to slip.
The time t 1 is the time at which a valve opens to dump the air in the system to atmosphere. With respect to the notch 35, the time t 2 is the time at which the air has bled off exponentially from both clutch units sufficiently for the clutch to begin to slip. Time t 3 is the time at which the valve recloses. Time t 4 is the time at which the pressure has risen exponentially past the clutch load line 34A. Finally time t 5 is the time at which the pressure is restored to normal clutch operating pressure.
In the arrangement according to the invention, the line 33 again represents the normal clutch operating pressure. Line 34B represents the clutch load line. Note that the clutch load line 34B is below the load line 34A. This is because, when the valve opens, the pressure in only one tube falls significantly (the tube without the restriction), and the pressure must drop to a lower level before the clutch will slip. The curve or pressure notch 38 represents the pressure in an inching cycle with the present invention. At time t 1 the valve 27 (FIG. 1) opens to dump the air in the system to atmosphere. Time t 6 represents the time at which the pressure has bled off sufficiently for the clutch to slip. Time t 7 is the time at which valve 27 (FIG. 1) recloses to restore operating pressure to the system. Time t 8 is the time at which the clutch pressure has risen (exponentially) to the clutch load line 34B and the clutch ceases to slip. Time t 9 is the time at which clutch pressure is restored to the normal clutch operating pressure represented by line 33.
It is of interest that clutch manufacturers are able to provide clutch linings with a dynamic coefficient of friction that is substantially the same as the static coefficient of friction. For this reason the graphs do not show any distinction. However, it will be apparent that the improvement achieved by this invention is not dependent upon this.
It will be noted that in FIG. 3, the pressure notch curve 35 has a relatively blunt tip where it penetrates the load line 34A for the short time interval t 2 to t 4 . In the present invention, with the needle valve 37 (FIG. 1) set appropriately to restrict the flow into and out of tube 16 (FIG. 1), the pressure notch curve 38 has a narrower and sharper tip where it penetrates the clutch load line 34B. The notch 38 may thus be said to approach more closely the ideal notch 32 of FIG. 2A. With the trend towards larger motors and clutches, this improvement can be commercially significant.
It is believed the preceding description has provided a clear understanding of the invention.
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A dual clutch for an inching arrangement in a load sharing drive which has two or more driving motors connected to a load through a dual clutch. The clutch has two (or more) clutch units mounted side by side on a driving shaft with an inflatable, flexible tube in each unit for pressing respective friction shoes outwardly, when inflated, against a surrounding cylindrical drum. The drum is mounted to a driven shaft. The driving shaft has a central bore connected through a solenoid operated valve to a supply of pressurized air when the valve is in an operating position and to an exhaust when the valve is in a dump position. Each of the tubes is connected to the central bore through a respective air line. A needle valve in one of the air lines provides a restriction to the flow of air into and out of the respective tube. The restriction is sufficient to substantially isolate the associated tube when the solenoid operated valve is operated to its dump position for a short time interval and then returned to its normal position. Thus, during a short pulse of reduced air pressure caused by the operation of the solenoid operated valve, the air flows largely out of only one tube thereby reducing the volume of air dumped to cause momentary slipping and improving the dynamic response of the clutch.
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BACKGROUND OF THE INVENTION
This invention relates to mix-heads for two chemically reactive streams and more particularly to such mix-heads for impingement mixing and stream transfer of two or more chemically reactive plastic compositions and wherein the mix-head includes recirculation passages.
Various high pressure mix-heads have been proposed that provide combined recirculation flow and impingement mixing injection and flow from the mix-head to a mold cavity. U.S. Pat. No. 4,175,874 issued Nov. 27, 1979 and U.S. Pat. No. 4,053,283 issued Oct. 11, 1977 disclose such a mix-head wherein the recirculation passages are formed in the piston. U.S. Pat. No. 3,706,515 issued Dec. 19, 1972 utilizes a constant section plunger. A separate movable slide plunger has recirculation paths that are selectively positioned to define a recirculation path between mix-head inlets and recycle outlets.
SUMMARY OF THE INVENTION
An object of the present invention is to provide an improved high pressure mix-head with a movable slide plunger of constant diameter and a mix-head body or sleeve which has fixed location, internal two-stream recirculation paths through which material recirculation is controlled by a separately movable valve piston element.
Another object of the present invention is to provide a mix-head of the preceding object and wherein the valve piston is hydraulically operated in response to positioning of the slide so as to permit recirculation of all streams prior to mixing and simultaneous injection of material into a mold during a fill cycle. On completion of injection the slide plunger returns to its initial position to displace previously mixed material in the mix-head into the mold cavity.
Still another object of the present invention is to provide a mix-head as set forth in either of the preceding objects wherein a fixed sleeve includes a pair of diametrically spaced longitudinal passages that are intersected by inlet and return ports which are selectively communicated in accordance with the axial position of a separate piston valve movably supported within the mix-head body.
In a preferred embodiment the mix-head includes a slide plunger having a driven end connected to a drive piston in a drive cylinder. The drive cylinder has an extension connected to a mix-head body. The mix-head body has at least first and second inlets respectively connected to sources of first and second chemically reactive plastic compositions. The mix-head body further includes first and second return ports respectively connected to first and second reservoirs for each of the compositions. The slide plunger is of constant diameter and reciprocates between mix and rest positions. When the plunger is positioned in its rest position it blocks communication between the aforesaid inlets and the mix chamber. A separate piston valve opens sleeve passages so that two separate compositions can be recirculated through separate bypass loops.
Other objects and advantages and a more complete understanding of the invention will be apparent to those skilled in the art from the succeeding detailed description of the invention and the accompanying drawings thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a multiple-stream mix-head including the present invention;
FIG. 2 is a longitudinal cross-sectional view of the mix-head of FIG. 1 showing a recirculation mode;
FIG. 3 is a side elevational view of the mix-head;
FIG. 4 is an end elevational view at the outlet of the mix-head head; and
FIG. 5 is a fragmentary view of the mix-head plunger in its mixing mode position.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In FIGS. 1-4 a mix-head assembly 10 is illustrated for mixing and feeding multiple reactive chemical compositions. The assembly 10 is of modular construction including a hydraulic drive 12 and a mix-head body 14. The assembly 10 is supplied with multiple chemical compositions, for producing moldings by an isocyanate poly addition process. One composition is stored in a reservoir 16. A pump 18 draws material from reservoir 16 to a first mix-head inlet 20 which may have a metering orifice 22 therein. If desired (and as shown in FIG. 1), the fixed metering orifice 22 can be replaced by a variable flow needle valve assembly 24 as shown in the FIG. 1 embodiment. In such case, adjustment of handle 26 will vary the proportional flow of the first composition to the mix-head. A second composition is stored in a reservoir 28. A pump 30 draws material from reservoir 28 to a second mix-head inlet 32 which has a metering orifice 34 therein which can be replaced by a variable flow needle valve assembly 36 like assembly 24 and serving the same purpose upon adjustment of its handle 38. In the illustrated embodiment two other mix-head inlets 20a and 32a are provided. They are shown plugged, it being recognized that if desired they can be associated with sources of third and fourth compositions and with systems for selectively controlling their flow through the mix-head.
The hydraulic drive 12 includes a cylinder 39 having a piston 40 reciprocated therein by hydraulic flow through a port 42 in a cylinder head 44. Cylinder head 44 has an annular seal 45 which engages the cylinder 39 to prevent leakage of fluid.
The piston 40 is connected to one end of a constant diameter slide plunger 46 by a rod retainer plug 48 that carries a fluid sealing O-ring 50. A cylinder base 52 has a longitudinally directed bore 54 formed therethrough for the plunger 46. A plurality of annular seal elements 56, 58, 60 seated in cylinder base 52 seal an inboard cylinder chamber 62 which in turn is sealed from the outboard cylinder chamber 64 by a ring seal 66 on the O.D. of piston 40. A hydraulic port 65 communicates with chamber 62 to supply and exhaust drive fluid in a known manner. Cap screws 67 connect the cylinder head 44 to the cylinder base 52 and cap screws 69 connect the mix-head body 14 to the hydraulic drive 12.
The plunger 46 extends through a bore 68 in the mix-head body 14 which is coaxial of bore 54. Bore 68 is of circular cross section and its I.D. is configured to slidingly, sealingly engage the O.D. of the plunger. The O.D. and the circular cross section of the plunger 46 is constant from end to end so as to maximize the structural capacity for a given plunger diameter.
The plunger 46 has grooves 70 on its distal end 72. The grooves 70 are circularly and longitudinally disposed on the distal end and carry O-rings 74, 76 sealingly engaged with the wall of bore 68. These seals are formed in place at assembly by injection of a suitable elastomeric sealing material through access port 98 which is then permanently plugged. A sleeve 75 is supported in a mix-head bore 77. It includes inlets 77a-77d to the bore 68. The sleeve 75 also has diametrically located slots 80a, 80b and 82a, 82b that are formed in the O.D. of the sleeve 75. The slots 80a, 80b and 82a, 82b intersect inlets 77a-77d and are connected to recirculation ports 81a, 81b which communicate with reservoirs 16, 28 and to recirculation ports 83a, 83b which are adapted to be connnected to reservoirs.
The recirculation ports 81a, 81b and 83a, 83b all define separate recirculation paths for each of the multiple compositions. Recirculation is controlled by a piston valve 85 when the mix-head assembly is positioned in the recirculation position of FIG. 2. In this position the piston valve 85 is located in the mix-head to open communication between the inlets 77a-77d and the ports 81a, 81b, 83a and 83b. In this position, the perimeter O-rings 90 are located to seal the bore 68 from the inlets 77a-77d. Also, the ports 81a, 81b and 83a, 83b are opened between the inlets 77a-77d and the reservoirs to define a path for recirculation of the chemical compositions following feed of the previously mixed compositions into the mold. The recirculation paths are sealed from one another by a seal bushing 86 interposed between the sleeve 75 and the I.D. wall of slidable piston valve 85. The bushing 86 carries a pair of spaced annular seals 88, 90 for sealing the recirculation.
Mixing is accomplished when plunger 46 is positioned inboard of the bore 68 as shown in FIG. 5. At the same time the piston valve 85 shift against two diametrically located key members 92. The piston valve 85 shuts off the recirculating streams by blocking ports 81a, 81b and 83a, 83b. The inlets 77a-77d are opened so that streams of chemicals will impact against one another to produce mixing within the bore 68 downstream of the retracted plunger end 94. The mixed constituents are then discharged through an outlet 96 from mix-head body 14 adapted to seat in a mold inlet. The mixed material flow into the mold by flow pressure until a predetermined amount of material has been injected after which the drive is energized by selectively controlling fluid to cause the piston 40 to shift the plunger 46 to the recirculation position in FIG. 2. The return stroke clears the bore 68 and shifts the piston valve 85 from the key members 92 to clear the recirculation paths.
Actuator position sensor 97 senses the position of the actuator piston 40 and provides an adjustable timed shift signal to the solenoid valve which supplies hydraulic fluid to shift piston valve 85 in timed sequence with the slide plunger 46. The ability to adjust the timing of the shift signal in response to material stream pressure trace data allows fine tuning of the mix-head valve functions.
While two chemical streams are discussed, the mix-head assembly can be modified to include three or more sets of operative inlets and recirculation ports if more than two chemical compositions are to be mixed. For example, in the case of three streams, the inlets and outlets can be disposed at points spaced one hundred and twenty degrees. The four-stream mix-head assembly illustrated will have all inlets and recirculation ports connected to a desired chemical stream for mixing in the head.
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A high pressure mix-head for use in reaction injection molding systems includes a full cross section plunger and a piston valve assembly selectively positioned in response to recirculation and pour cycles to control flow through recirculation passages formed on the O.D. surface of a mix-head sleeve.
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CROSS-REFERENCED APPLICATIONS
[0001] This application claims priority to U.S. Provisional Patent Application No. 60/632,398, filed on Dec. 2, 2004, U.S. Provisional Patent Application No. 60/632,420, filed on Dec. 2, 2004, U.S. Provisional Patent Application No. 60/632,397, filed on Dec. 2, 2004, and U.S. Provisional Patent Application No. 60/676,407, filed on Apr. 29, 2005, all of which are hereby incorporated by reference in their entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a method of producing expanded thermoformable materials. More particularly, the present invention relates to a cost effective and energy efficient method for continuously producing expanded thermoformable materials with open or closed cell wall structures.
[0004] 2. Description of the Prior Art
[0005] Processes used to make expanded thermoformable materials typically involve placing a thermoformable polymeric material blank between mold plates, which are attached to a heated press. The thermoformable polymeric material blank is heated to a temperature at which the thermoformable material will adhesively bond with the mold plates by hot tack adhesion. The mold plates are then separated with the thermoformable material still adhered to the mold plates, so as to affect an expansion of the cross-section of the thermoformable material.
[0006] Typically, the surfaces of the mold plates that are bonded to the thermoplastic material blank have a plurality of perforations thereon. The thermoplastic material will adhesively bond to the non-perforated portion of this surface so that when the mold plates are separated a plurality of cells will be formed within the cross-section of the expanded thermoformable material. Generally, these perforations can have a variety of different geometries and can be arranged in an array of patterns on the surface of the mold plates, thereby creating thermoformable materials having a variety of cross-sectional geometries. Such methods for expanding thermoformable materials are set forth in U.S. Pat. No. 6,322,651, issued on Nov. 27, 2001 to Phelps, U.S. Pat. No. 4,113,909, issued on Sep. 12, 1978 to Beasley, U.S. Pat. No. 4,164,389, issued on Aug. 14, 1979 to Beasley, U.S. Pat. No. 4,315,051, issued on Feb. 9, 1982 to Rourke, U.S. Pat. No. 4,269,586 issued on May 26, 1981 to Ronayne, U.S. Pat. No. 4,264,293, issued on Apr. 28, 1981 to Rourke, and U.S. Pat. No. 4,315,050 issued on Feb. 9, 1982 to Rourke, each of which is incorporated herein by reference in their entirety.
[0007] One disadvantage with these processes is that there are large economic losses due to the use of discrete thermopolymer sheets. These sheets are made from thermoplastic resin which is heated to a high temperature to cause it to melt and be formed through dies under pressure. After extrusion from the dies the sheet material is polished to give it a good finish, cooled, sealed and cut. Then it is stored and eventually transported to a coreformer or expander where it must be unsealed and reheated before being formed into expanded honeycomb core product. The process of expanding the thermopolymer sheet destroys the polish that the sheet had been given during the extrusion process. There are multiple sources of waste associated with this process, namely the additional manpower and time needed to perform these tasks.
[0008] In addition, the cost of production is substantially increased because of the amount of wasted energy in these conventional processes. Each thermoformable sheet material must be reheated since all of the energy from the original heating of the resin in the extruder is lost. The current methods require the thermopolymer material used to manufacture the expanded honeycomb core product to be cooled twice, once after extrusion and once after expansion. Thus, the cost of production is increased because energy must be purchased to heat each new sheet of thermoformable material prior to expansion, and all of this energy is wasted during the initial cooling process.
[0009] A further disadvantage of the previous methods is that many of the thermoformable materials are hydrophilic and absorb moisture from the air. This moisture must be removed prior to expanding the material for two reasons. First, the moisture will absorb heat and unnecessarily require additional energy to bring the thermoformable material up to expansion temperature. Secondly, and perhaps more importantly, the moisture in the thermoformable material will expand as it turns to vapor at the thermoforming temperatures resulting in voids, fissures and other defects in the finished expanded honeycomb core product, making it structurally unsound and commercially unacceptable. To make acceptable expanded honeycomb core product from thermoformable sheet material, that material needs to be heated in an oven to drive off the absorbed moisture. This of course is an additional step that requires energy, manpower, time, floor space, additional equipment and ultimately cost.
[0010] All of these processes envision a monolithic thermoformable sheet material as the starting point for the thermoforming expansion process. Typically, these materials are produced by an extruder of a known thermoplastic such as ABS, polypropylene, polystyrene, polycarbonate, etc. In reality, the process of efficiently forming a good quality expanded thermoformable material requires a more sophisticated understanding of the material's viscoelastic properties.
[0011] Furthermore, another disadvantage of the conventional processes described above are that they are neither automated nor continuous from the input of the raw material to the finished product, and typically require multiple manufacturing personnel, multiple heating and cooling stages, and other steps that are necessary to produce one expanded thermoformable product. Obviously, the use of multiple personnel greatly increases the cost of manufacturing, together with the long product cycle times and energy loss.
[0012] Finally, the existing processes have inherent limitations in terms of volume throughput and capacity and the ability to scale-up to meet large customer demands. All the aforementioned processes are batch processes and cannot deliver volume production yields. At the same time, the built-in economic and energy disadvantages of these processes make them impractical in meeting the requirement of large scale demand.
[0013] Accordingly, there is a need for an improved method of continuously producing expanded thermoformable materials that avoids the aforementioned disadvantages.
[0014] It is an object of the present invention to provide a method for producing expanded thermoformable materials that allows for the continuous processing of the materials.
[0015] It is a further object of the present invention to provide a method for producing such materials that directly integrates the forming and processing of the raw material inputs.
[0016] It is a further object of the present invention to provide a method for producing the materials that substantially reduces the product cycle time, labor costs, and energy consumption of the systems and methods currently available.
[0017] It is a further object of the present invention to provide a method for producing a material that substantially improves the volume production capacity and throughput of currently available systems.
[0018] It is a further object of the invention to prevent the absorption of water by the thermoformable material, which saves on labor costs and improves the processing time of said materials over currently available systems.
SUMMARY OF THE INVENTION
[0019] The present invention provides a cost-effective and energy efficient method for continuously producing expanded thermoformable materials. This method comprises the steps of: providing raw thermoformable material (such as thermoplastic flake or pellets) into an extruder or molds; heating the material in the extruder or molds; extruding or molding planar sheet material as a single extrusion or co-extrusion of suitable gauge and width; cutting or shearing the extruded or molded material to suitable lengths for expansion in a coreformer or expander while it is still hot; conveying this hot thermoformable material into a coreformer or expander having heating and cooling platens with an arrangement of holes on one or both forming platens; expanding the heated thermoformable material in this expansion and cooling module; and cooling the expanded thermoformable material by changing the temperature of the platens to facilitate release from the platens and to maintain the structural integrity of the thermoformable material.
[0020] In another embodiment of the present invention, a buffer or loader can be located between the extruder or mold and the coreformer or expander. The buffer or loader can hold the formed sheets of material and keep them at an elevated temperature before they are conveyed to the coreformer or expander.
[0021] In another embodiment of the present invention, the heating expansion and cooling of the core material can be performed at distinct and separate stages of the coreformer or expander.
[0022] In another embodiment of the present invention, the raw thermoformable material supplied to the extruder or mold can be a heterogeneous mixture. This mixture can be co-extruded so that the sheet of material conveyed to the coreformer or expander has an outer and inner layer of material.
[0023] In another embodiment of the present invention, the raw material selected can contain physical properties, such as low viscoelasticity, that allow for the formation of holes or tears in the side of the formed material. These holes or tears can allow for the passage of materials through the finished material.
[0024] In another embodiment of the present invention, fibers can be added to the raw materials used to make the core material.
[0025] In another embodiment of the present invention, fillers can be added to the raw materials used to make the core material.
[0026] In another embodiment of the present invention, nanotubes, especially carbon nanotubes, can be added to the raw materials used to make the core material.
[0027] In another embodiment of the present invention, the fibers, fillers, or the nanotubes added to the raw materials described above are conductive or have other electrical, electrostatic or electromagnetic properties.
[0028] In another embodiment of the present invention, rubber or other flexible polymeric material can be added to the raw materials.
[0029] In particular, the present invention includes a method for forming an expanded thermoformable material, said method comprising: feeding said thermoformable material to an extruder which heats said thermoformable material and thereafter extrudes a thermoformable sheet or layer; and conveying said thermoformable sheet to an expander (e.g., press expander), wherein said expander expands a cross-section of said thermoformable sheet to form a core layer having a thickness larger than said thermoformable sheet and wherein air cells are disposed throughout said core layer. The method may further comprise the step of conveying said thermoformable sheet to a buffer loader prior to conveying said thermoformable sheet to said expander. Preferably, the buffer loader has a heated environment to maintain said thermoformable sheet at a predetermined temperature. The buffer loader is capable of storing at least one thermoformable sheet therein. Furthermore, the method may optionally include a step of cutting said thermoformable sheet into predetermined lengths before conveying said thermoformable sheets to said buffer loader. The expander can also comprise a separate heating station and cooling station.
[0030] The thermoformable material can also be a heterogeneous mixture of thermoplastic material, such that a thermoformable sheet is formed which comprises at least two layers of differing thermoplastic materials.
[0031] The thermoformable material can also have a low viscoelasticity, such that upon expansion in the expander, tears or holes are formed in the core layer cell walls.
[0032] All of the above embodiments can further have a system that can control the combined extrusion and coreforming process, such as by regulating temperature, rate of movement of the materials, buffering or loading of the extruded sheets, expansion of the material, cooling, loading, unloading, or any other aspect of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0033] FIG. 1 is a block diagram according to a first embodiment of the present invention;
[0034] FIG. 2 is a block diagram according to a second embodiment of the present invention;
[0035] FIG. 3 is a block diagram according to a third embodiment of the present invention;
[0036] FIG. 4 is a block diagram depicting a process utilizing heterogeneous raw materials according to the present invention;
[0037] FIG. 5 is schematic representation of a cross-sectional side view of a conventional core material with internal cells; and
[0038] FIG. 6 is schematic representation of a cross-sectional side view of a core material with the lateral open cell structure according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0039] Referring to FIG. 1 , a first embodiment of the present invention, generally referred to by reference numeral 10 , is shown. System 10 has hopper 20 , extruder 30 , conveyor system 40 , and coreformer or expander 70 .
[0040] To begin the process of the claimed invention, thermoplastic raw material 15 is loaded into hopper 20 . This material is usually in pellet form. Suitable examples of such material include, but are not limited to, high impact polystyrene, polycarbonate, acrylonitrile butadiene styrene, homo or co-polymer polypropylene, low and high density polyethylene and combinations thereof.
[0041] Hopper 20 then feeds the raw material into extruder 30 . These materials can be extruded or molded utilizing unfilled polymers, polymer alloys, fiber/filler/nano reinforced polymers, flexible polymers, recycled polymers or combinations of the above. Inside extruder 30 , the raw material is heated to a temperature as high as about 300° C., at which point the material becomes a viscous liquid. In this state, it is forced through under pressure, typically by a screw pump mechanism, through a set of dies generally in the shape of a flat sheet. While the present invention can form expanded material from a variety of thicknesses, about 0.100″ to about 0.250″ inches represents a common starting thickness.
[0042] By the time the material has been forced through the dies into sheet form, it has cooled to approximately about 250° C., and, while it is still soft and flexible, it is no longer in a liquid state. The material exits extruder 30 in the form of a sheet, referenced in FIG. 1 by numeral 55 . Thermoplastic sheet 55 passes through first upper and lower rollers 42 and 44 , which guide sheet 55 to a shear mechanism 46 . Shear mechanism 46 cuts sheet 55 into the desired lengths. In the shown embodiment, shear mechanism 46 is a simple vertical cutting shear; however, other methods of cutting sheet 55 into the desired lengths are contemplated by the present invention, including but not limited to using laser cutters or a water jet.
[0043] Sheet 55 then passes through a second set of upper and lower rollers 48 and 50 , which guide sheet 55 to coreformer or expander 70 . In general, it is desirable to keep sheet 55 as hot as possible prior to its entering the coreformer or expander so as to minimize the amount of energy used in re-heating it. Sheet 55 should only be allowed to cool to the minimal temperature necessary to prevent it from gross distortions of shape during the brief transit time from extruder to coreformer or expander. This is a substantial advantage over currently available systems. Since sheet 55 is kept at an elevated temperature at this point, the material sheet 55 does not cool completely, which saves on the energy and manpower costs that would be involved in reheating the sheet later on. In other words, the present invention eliminates the substantial costs of heating the thermoformable material from ambient temperature to the temperature at which it will adhere to the platens of the coreformer or expander (discussed below). Waste heat from the process of cooling the expanded thermoformable material (discussed below) can be reused to help maintain the extruded material at a high temperature. Additionally, keeping sheet 55 hot between extruder 30 and coreformer or expander 70 eliminates the need to remove moisture from sheet 55 because the temperature of the material is high enough to prevent water from being absorbed. Since the process is continuous, the transit time between extruder 30 and coreformer or expander 70 is minimized, which also helps to prevent the absorption of water by sheet 55 . This results in lower labor costs and helps to improve the overall cycle time of the machine. Finally, since the sheet 55 is kept at an elevated temperature during the entire time from when it leaves the extruder 30 and before it enters coreformer or expander 70 , the present invention eliminates the substantial amount of time to reheat the thermoformable material that is needed by currently available systems.
[0044] Sheet 55 is then conveyed to coreformer or expander 70 . Coreformer or expander 70 has upper and lower presses 72 and 74 . Coreformer or expander 70 further has upper and lower platens 76 and 78 , which are operably connected to upper and lower presses 72 and 74 , respectively. Once in coreformer or expander 70 , upper and lower platens 76 and 78 heat sheet 55 to a temperature at which the thermoformable material of sheet 55 adhesively bonds to upper and lower platens 76 and 78 , usually in the range of about 100° C. to about 400° C. The critical temperature at which the thermoformable material of sheet 55 will adhere to upper and lower platens 76 and 78 will depend on the characteristics of the material selected. Heated platens 76 and 78 can be composed of aluminum, copper, steel or other suitable metals and alloys.
[0045] Upper and lower press 72 and 74 then separate, pulling upper and lower platens 76 and 78 apart, and effecting an expansion of the cross-section of sheet 55 to the desired width. The surface of the platens 76 and 78 which comes into contact with the thermoformable material can have perforations thereon, thereby creating cells in the cross-section of the expanded thermoformable material during the expansion process. Alternatively, each set of coreformer or expander platens may have either the same or different diameter perforations thus enabling the creation of core material having different or the same cell cross-sections. The coreformer or expander platens can also have one platen with a pattern of perforations and one platen with a smooth face, so that the system can produce core material with an integral facing on only one side. An integral facing is defined a connected, homogeneous layer on one side of the core material.
[0046] Sheet 55 , after being expanded by upper and lower platens 76 and 78 of coreformer or expander 70 , is transformed into core material 90 . Core material 90 is then cooled by changing the temperature of upper and lower platens 76 and 78 , such that core material 90 is cooled to a temperature sufficient for maintaining its structural integrity and to facilitate release from upper and lower platens 76 and 78 . Upper and lower presses 72 and 74 then retract, which retracts upper and lower platens 76 and 78 and releases core material 90 . Core material 90 is ejected from the machine either by manual means or by an automated unloader system which pushes the core from the machine.
[0047] Referring to FIG. 2 , a second embodiment of the present invention is shown, generally referred to by reference numeral 110 . System 110 has hopper 120 , extruder 130 , conveyor system 140 , and coreformer or expander 170 , which are identical to the similarly numbered components of system 10 discussed above. System 110 also has buffer loader 160 .
[0048] In system 110 , the process for creating the thermoformable materials is the same as that of system 10 , up until the point at which sheet 155 is loaded into buffer loader 160 . Thus, raw materials 115 are fed into hopper 120 , which guides material 115 into extruder 130 . Extruder 130 forms sheet 155 out of raw materials 115 . Sheet 155 is guided through first upper and lower rollers 142 and 144 , and then to shear 146 , which cuts sheet 155 to a desired length. Sheet 155 is then guided by second upper and lower rollers 148 and 150 to buffer loader 160 .
[0049] Buffer loader 160 holds sheet 155 at an elevated temperature while it is waiting to be loaded into coreformer or expander 170 . One advantage to this feature, as described above, is that ambient moisture is not absorbed by sheet 155 . In addition, buffer loader 160 has the ability to hold multiple sections of sheet 155 , which allows for different run rates between extruder 130 and coreformer or expander 170 . This helps to ensure the efficient and cost-effective continuous production capability of system 110 , and the minimization of manpower to keep the system running smoothly. This is particularly important, as extruders require significant amounts of time and energy to start up and to shut down. Finally, by keeping sheets 155 at an elevated temperature, buffer loader 160 helps to decrease the energy costs of the system because sheets 155 do not have to be reheated from room temperature once they are conveyed into coreformer or expander 170 .
[0050] There are several possible configurations of buffer loader 160 that can be used in the system of the present invention. A preferred buffer loader includes racks large enough to hold a sheet of core with the racks mounted on a vertical drive mechanism that can move the racks up and down both for temporary storage as well as for aligning with the opening of the coreformer or expander and loading it. Another version would provide for the racks to be mounted on a continuous loop. Because the material sheets 155 stored by buffer loader 160 are hot and somewhat soft and flexible, the racks or shelves that the material rests on in buffer loader 160 must be made of appropriate materials to keep the shape of the material sheets 155 while being able to withstand the heat.
[0051] After sheets 155 are conveyed from buffer loader 160 into coreformer or expander 170 , core material 190 is formed in the same way as core material 90 of system 10 . Upper and lower platens 176 and 178 heat sheet 155 to the temperature at which sheet 155 will adhesively bond to upper and lower platens 176 and 178 . Upper and lower platens 176 and 178 then retract, expanding sheet 155 into core material 190 . Upper and lower platens 176 and 178 then cool core material 190 to a temperature sufficient for maintaining its structural integrity and to facilitate release from upper and lower platens 176 and 178 . Upper and lower platens 176 and 178 then retract, releasing core material 190 .
[0052] Referring to FIG. 3 , a third embodiment of the present invention is shown, generally referred to by reference numeral 210 . System 210 has hopper 220 , extruder 230 , conveyor system 240 , and buffer loader 260 , which are identical to the similarly numbered components of system 110 discussed above. System 210 also has coreformer or expander 270 . Coreformer or expander 270 further has heating station 271 and cooling station 281 .
[0053] System 210 performs in a substantially similar manner to system 110 , with the important exception that there are two separate stages in coreformer or expander 270 , as opposed to the coreformers of the above embodiments. Thus, when sheet 255 leaves buffer loader 260 , it enters heating station 271 of coreformer or expander 270 first. Heating station 271 has upper heating press 272 and lower heating press 274 . Upper and lower heating platen 276 and 278 are operably connected to upper heating press 272 and lower heating press 274 respectively. Upper and lower heating platens 276 and 278 engage sheet 255 and heat it to the temperature at which sheet 255 will adhesively bond to upper and lower platens 276 and 278 . Similar to the embodiments described above, the platens then retract, expanding sheet 255 into core material 290 . Core material 290 is then conveyed to cooling station 281 , which has upper cooling press 282 , lower cooling press 284 , upper cooling platen 286 , and lower cooling platen 288 . The transfer of core material 290 into cooling station 281 is accomplished by a rotary chain belt, which pulls core material 290 into cooling station 281 .
[0054] Upper and lower cooling platens 286 and 288 cool core material 290 to a temperature sufficient for maintaining its structural integrity and to facilitate release from upper and lower cooling platens 176 and 178 . Upper and lower cooling platens 176 and 178 then retract, releasing core material 190 .
[0055] Heating station 271 and cooling station 281 can be enclosed in a housing (not shown) capable of capturing the heat that escapes from core material 290 during the cooling process. This heat can be recycled to heating station 271 to heat a subsequent sheet 255 , thereby conserving energy during operation of the continuous process. With this additional recycled energy heating station 271 can be kept at a high enough temperature to bring the sheet 255 to an adhesion temperature with a minimal amount of additional external energy.
[0056] Referring to FIG. 4 , another type of sheet that can be made by the extruder or molder of the above embodiments of the present invention is shown, and referred to by reference numeral 355 .
[0057] To make sheet 355 , heterogeneous raw material can be fed into the hopper, such as hopper 20 of system 10 , hopper 120 of system 110 , and hopper 220 of system 210 . The raw materials can be extruded such that a three-layered sheet 355 is formed, having a top layer 356 , bottom layer 357 , and middle layer 358 . Such a heterogeneous material can be made by a process known as co-extrusion, whereby different thermoformable materials are simultaneously extruded as layers into one sheet-type material. The methods for co-extrusion are known to those of ordinary skill in the art.
[0058] One advantage to the use of heterogeneous materials is that it can offer substantial energy savings over presently available systems. In one embodiment, for example, two materials can be selected for extrusion so that top layer 356 and bottom layer 357 of sheet 355 are made of the same material having excellent hot tack and adhesion properties at a low temperature. Middle layer 358 of sheet 355 can be made of a different material having excellent melt flow characteristics at a low temperature. Thus, this embodiment saves energy in the mold or extruder, because due to the melt flow characteristics of middle layer 358 less heat is required to melt the raw material than would otherwise be needed for a homogeneous mixture. Less energy is also required during the heating and cooling processes of coreformer or expander 370 , because due to the hot tack properties of top and bottom layers 356 and 357 less energy is required to heat and subsequently cool sheet 355 during the formation of core material 390 . In the shown embodiment, sheet 355 has three layers with the top and bottom layers being made of the same material; however, the present invention contemplates the use of a variety of different combinations and numbers of layers.
[0059] In another embodiment of the present invention, a raw material can be used that has reduced or low viscoelastic properties. The choice of a raw material with low viscoelasticity will be stiffer under the processing conditions of the coreformer or expander and this will cause the side walls of the internal cells to tear during a core material formation process such as those outlined above. The core material retains a sufficient amount of material and structure to the cell walls to maintain the strength and integrity of the overall core material sheet.
[0060] Referring to FIG. 5 , a typical cross section of a core material 455 is shown. Core material 455 can have a number of side-walls 456 that retain the overall integrity of the core material. Referring to FIG. 6 , a cross section of a core material 555 formed with the above described method is shown. Core material 555 can have a number of side walls 556 , which have a number of tears 557 dispersed throughout. The tears 557 , however, are not in such abundance that the overall structural integrity of core material 555 is compromised.
[0061] These tears 557 in the side walls 556 form holes that can allow air, liquids and even fine or granular solids to pass through parallel to the surface of the expanded thermoformable material. In addition, these lateral holes form a network of passageways from one end of core material 555 to the other, because the tears of one cell interface with the tears of adjacent tears in the core material. The combined effect of the lateral hole network and the through-hole network together with the rigidity and structure of the remaining cell wall, creates an expanded thermoformable material that is both porous yet strong and rigid.
[0062] In another embodiment of the present invention, fibers can be added to the raw materials during the extrusion process. These fibers can be made of a variety of materials, such as plastic, glass, carbon, and metal, all of an appropriate length and thinness so as to extrude properly in the sheet material. Such a thermoplastic sheet material, when expanded, will be significantly stronger as the fibers add strength to the cell walls between the two planar surfaces. The cell walls in the normal expansion process are thinner than the planar surfaces and the addition of the fiber, especially its content in the expanded cell walls, adds significantly to the finished core panels' compressive strength. The addition of the fiber, especially its content in the expanded panel's surfaces, adds significantly to the finished core panels' flexural strength. Due to the higher flexural strength of the finished product, a material of thinner starting thickness can be used to achieve the same performance that would normally result from a thicker material. This reduces the energy requirements needed to form the core due to the thinner mass to be heated.
[0063] In another embodiment of the present invention, nanotubes, especially carbon nanotubes, can be added to the raw materials during the extrusion process. These nanotubes act in a similar manner to fibers, but are easier to extrude in conjunction with the themoplastic, and the thermoplastic sheet is also easily formable into expanded core material. Such a thermoplastic sheet material, when expanded, will be significantly stronger as the nanotubes add strength to the cell walls between the two planar surfaces. The cell walls in the normal expansion process are thinner than the planar surfaces and the addition of the nanotubes, especially their content in the expanded cell walls, adds significantly to the finished core panels' compressive strength. The addition of the nanotubes, especially their content in the expanded panel's surfaces, adds significantly to the finished core panels' flexural strength. Due to the higher flexural strength of the finished product, a material of thinner starting thickness can be used to achieve the same performance that would normally result from a thicker material. This reduces the energy requirements needed to form the core layer due to the thinner mass to be heated.
[0064] In another embodiment of the present invention, the fibers or the nanotubes added to the raw materials described above are conductive or have other electrical, electrostatic or electromagnetic properties. Such a thermoplastic sheet material, when expanded, will assume these properties in addition to having the additional strength discussed above.
[0065] In another embodiment of the present invention, rubber or other flexible polymeric material can be added to the raw materials. The cell walls of the expanded thermoplastic material made from these sheets will have the ability to flex under pressure or impact. This gives the finished expanded thermoplastic panel the ability to absorb energy and return to its original shape without permanent deformation.
[0066] Any of the above described additives, namely, fibers, nanotubes, fibers or nanotubes with electrical properties, rubber, or other flexible polymeric material can be added to the raw materials used in any of the above described systems, namely, systems 10 , 110 , and 210 . In addition, the above-described additives can be added to the raw materials used to form sheets 355 , 455 , and 555 .
[0067] The present invention can also have a control system, using computer(s) software, sensors, actuators, and/or programmable logic controllers, used to control the extrusion, temperature, rate of movement, buffering, loading and unloading of the entire coreforming system, from raw material to finished product. Such a control system can be used in any of the above described embodiments of the present invention.
[0068] The present invention having been thus described with particular reference to the preferred forms thereof, it will be obvious that various changes and modifications may be made therein without departing from the spirit and scope of the present invention as defined herein.
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A method and apparatus for continuously and cost-effectively producing expanded thermoformable materials encompassing the steps of: providing raw thermoformable material into an extruder or mold; heating the material in the extruder or mold; extruding or co-extruding molding planar sheet material of suitable engineering performance parameters to a gauge and width; cutting or shearing the extruded or molded material while it is still hot to suitable lengths for expansion in a coreformer; conveying the hot thermoformable sheet material in between forming platens; heating the thermoformable material to a temperature at which the material adhesively bonds to the platens; expanding the cross-section of the thermoformable material; and then cooling the expanded thermoformable material by changing the temperature of the forming platens such that the thermoformable material can maintain its structural integrity and be released from the platens.
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CROSS-REFERENCE
This application is a continuation-in-part of U.S. patent application Ser. No. 08/633,225, filed on Apr. 16, 1996.
FIELD OF THE INVENTION
This device relates to tamper evident closures having a push-pull resealable tamper evident pour spout.
BACKGROUND OF THE INVENTION
Prior art closures having a pour spout or the like are disclosed in U.S. patent application Ser. Nos. 08/332,140 (filed Oct. 31, 1994), 08/633,225 and U.S. Pat. Nos. 5,104,008 and 5,465,876.
Some of these prior spout closures provide tamper evidency and have tamper evident pour spouts but which are not always leak proof at spout closure interface. Generally, prior art push-pull spouts that are reusable do not provide effective sealing at the juncture between the spout opening and the plug positioned in the opening when the spout is closed. Because of the very small diameter of the opening and the concern for safety, it is not possible to add non-integrated sealing means. The present invention solves this problem by utilizing a closure plug which combines a circular closure disk with an integral annular skirt depending from the periphery of the disk thereby defining a hollow cavity for the plug interior and increasing the structural flexibility of the plug. The increased structural flexibility provided by the hollow cavity causes inward deformation of the plug skirt upon engagement with annular flanges integrated into the periphery of the spout closure central opening to create a form-fitting leak tight seal.
Additionally, the present invention provides an improved means of locking the closure to a bottle neck. Projections extending radially inward from the inner surface of the tamper evident band form an upwardly angled "hook" shape for engaging the sealing flange on the bottle neck. This "hooking" engagement prevents removal of the closure while the tamper evident band remains intact.
Finally, a plurality of circumferentially spaced dimples optionally extend from the exterior wall of the pour spout. These dimples engage vertically spaced inturned annular flanges on the interior surface of the spout closure to faciliate breaking the frangible elements connecting the tamper evident band to the spout closure.
Accordingly, it is an object of the present invention to provide an effective seal for a push-pull spout for reusable containers.
It is a further object of the invention to provide a substantially leak proof tamper-evident closure having a reusable, push-pull spout.
It is a further object of the present invention to provide a reusable, push-pull pour spout closure that utilizes a closure plug having increased structural flexibility to provide a more effective leak tight seal.
It is a further object of the present invention to provide a reusable, push-pull pour spout closure that utilizes an upwardly angled locking means to prevent removal of the closure from a bottle neck with the tamper evident band intact.
It is a further object of the present invention to provide a means for faciliating the breakage of frangible elements connecting the tamper evident band to the spout closure.
SUMMARY OF THE INVENTION
The present invention provides a tamper evident plastic closure with a tamper evident push-pull pour spout which is substantially leak proof. Generally, the present invention includes a push pull resealable pour spout with an opening therein which is partially closed by a second top having a secondary opening therein and a plug space thereabove with upwardly angled legs formed integrally with the closure. The plug takes the form of a circular closure disk having an integral annular skirt depending from the periphery of the disk that attaches the plug to the angular legs thereby defining a hollow cavity for the plug interior and increasing the structural flexibility of the plug. Integrated into the periphery of the secondary opening is at least one and preferably two annular flanges which engage the plug skirt when the secondary opening is closed to seal the spout. The annular flanges cause inward deformation of the plug skirt upon engagement to create a form-fitting leak proof seal.
The entire closure is preferably locked to a bottle neck by a series of projections that extend radially inward from the inner surface of a tamper evident band attached to the bottom edge of the closure body. The projections have a flanged edge preferably lying at an angle with a plane normal to the inner surface of the tamper evident band, thereby defining a grooved "hook" which slides over the locking flange on the bottle neck when the closure is placed on the container but which engages and locks the closure to the container neck when removal of the closure is attempted with the tamper evident band intact.
A plurality of circumferentially spaced dimples optionally extend from the exterior wall of the pour spout. These dimples engage vertically spaced inturned annular flanges on the interior surface of the spout closure to faciliate breaking the frangible elements connecting the tamper evident band to the spout closure. Other advantages of the present invention will become apparent from a perusal of the following detailed description of a presently preferred embodiment taken in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a vertical cross-section through a portion of the resealable closure with the push pull pour spout in an opened position;
FIG. 1a is an enlarged partial section of secondary openings;
FIG. 2 is a vertical cross-section through a portion of the resealable closure with the push pull top in a closed position;
FIG. 3 is a perspective view of the resealable closure;
FIG. 4 is a perspective view of a portion of the resealable closure;
FIG. 5 is a top plan view of the resealable closure;
FIG. 6 is a side elevational view of the resealable closure; and
FIG. 7 is a partial enlarged cross-sectional view of a portion of the resealable closure showing the bottle neck configuration.
FIG. 8 is an exploded view of the locking means of the present invention.
FIG. 9 is an exploded view of the secondary closure plug of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIGS. 1, 2 and 3 of the drawings, a resealable closure 10 preferably made of high density polyethylene includes a push-pull secondary closure 11, which also is made of high density polyethylene except the spout which is preferably low density polypropylene, positioned thereon. Closure 10 comprises a top portion 12 with an integral depending annular flange 13 extending therefrom. A plurality of circumferentially spaced frangible elements 14 extend from the lower edge of depending flange 13 to a tamper evident ring 15 integrally molded with the closure. Tamper ring 15 is preferably of the same diameter as that of the annular flange 13 and includes a plurality of circumferentially spaced inwardly facing projections 16 thereon.
Referring to FIGS. 1 and 7 of the drawings, projections 16 are circumferentially spaced about the inner surface of said tamper evident ring 15 and are positioned so that they are engagable under an annular locking flange 17 to lock the closure 10 on a bottle neck 18 as seen in FIG. 7 of the drawings. As can be seen in FIG. 8, projections 16 comprise edges 16a defining grooves 16b formed on radially upwardly extending annular flanges 16c. Flanges 16c are preferably discontinuous but can be continuous. Edge 16a and groove 16b provide a "hook" shape for engaging the annular locking flange 17 which has a radius substantially the same as groove 16b. The grip provided by engagement of the hooked projections 16 to annular locking flange 17 prevents removal of the closure 10 from the bottle neck 18 while tamper evident ring 15 is intact. Because groove 16b is undercut, a mold core must be used that frees or permits removal of undercut prior to stripping the closures from the mold. Various techniques are known to those skilled in the art including the use of movable core sleeves which free the undercut section of the mold.
Referring to FIG. 1, an opening 19 is preferably formed in the center of the top portion of the cap 12 with an upstanding cylindrical pour spout 20 positioned in registry with opening 19. The upper end of the pour spout 20 includes a secondary top portion 21 thereon which is apertured at 22. A closure plug 23 is positioned on the secondary top portion 21 in spaced relation to aperture 22 by a plurality of circumferentially spaced angularly arranged upwardly extending supports 24. Referring to FIG. 9, the plug 23 is formed by a circular closure disk 41 having an integrally molded annular skirt 42 depending from the periphery of the disk 41. The sidewall of skirt 42 is dimensioned to be thin enough to allow inward deformation of the sidewall upon contact with the central opening surface 27 of spout cap 25 while at the same time being thick enough to ensure that the plug 23 will not break off with repeated use. Skirt 42 attaches plug 23 to the angular supports 24 thereby defining a hollow cavity 43 for the plug interior.
A push-pull cap 25 is positioned on the upstanding cylindrical pour spout 20 and has a top surface 26 with a central opening 27 therein which is designed to register with the plug 23 to form a secondary closure when the top cap 25 is in a closed position resting on the secondary top portion 21 of the upstanding cylindrical pour spout 20 as illustrated in FIG. 2. Located on the inner surface of central opening 27 is at least one, but preferably a pair of annular, preferably arcuate, flanges 33 which radially project into opening 27. As shown in FIG. 1a, a pair of annular flanges 33a and 33b are integrally molded with the inner surface of central opening 27. A pair of flanges 33a and 33b are especially preferable for sealing fluids such as water. However, a single flange is sufficient for containers used for fluids having a higher viscosity such as fruit juice.
The radially projecting flanges 33 engage depending plug skirt 42 to form a leak tight seal for the spout 20. The attachment of skirt 42 to the periphery of disk 41 increases the structural flexibility of the plug 23 thereby forcing the plug skirt 42 to flex and inwardly deform upon engagement with radially projecting flanges 33. This deformation causes a form fit which increases the tightness of the secondary closure seal thereby resulting in a superior leak-tight arrangement when compared to other designs currently in the state of the art.
Push-pull cap 25 has a depending cylindrical body member 28 with a plurality of annularly spaced frangible elements 29 connected on its lower perimeter edge to a secondary tamper indicating band 30. The cylindrical body member 28 has a pair of vertically spaced inturned annular flanges 31 which slidably engage the outer surface of the upstanding cylindrical pour spout 20. The secondary tamper evident band 30 also has an internal annular flange 32 which is slidably engaged at the exterior of the upstanding cylindrical pour spout 20. The upstanding cylindrical pour spout 20 has two outwardly extending annular flanges 34a and 34b, respectively on the exterior thereof. The flange 32 is oppositely disposed with respect to the secondary top portion 21 and outwardly extending flange 34a, said outwardly extending flange 34a being positioned above the top 12 of the cap 10 and being oppositely disposed to and between the annular flanges 31 on the cylindrical body member 28 and the secondary tamper evident band 30, respectively.
In assembled form as illustrated in FIGS. 1, 2, 3 and 6 of the drawings, the secondary tamper evident band 30 is joined by the frangible elements 29 to the cylindrical body member 28. The push-pull cap 25 is incapable of moving upwardly due to the interengagement of the internal annular flange 32 with the outwardly extending flange 34a on the cylindrical pour spout 20. Thus the cylindrical body member 28 of the push-pull cap 25 is incapable of vertical movement such as required to move the apertured top surface 26 above the plug 23 until sufficient force is applied to the push-pull cap 25 to break away the frangible elements 29 whereby the push-pull cap 25 can move to the position illustrated in FIG. 1 of the drawings wherein the opening 27 therein moves upwardly and away from the plug 23. The inturned annular flanges 31 on the cylindrical body member 28 cannot move above the outwardly extending annular flange 34b on the upstanding cylindrical pour spout 20 so that the push-pull cap 25 cannot be removed therefrom. As shown in FIGS. 1 and 5, a plurality of circumferentially spaced dimples 44 optionally extend from the exterior wall of the pour spout 20. Dimples 44 engage the inturned annular flanges 31 on the cylindrical body member 28 of the push-pull spout closure 25 to faciliate breaking the frangible elements 29 connecting the tamper evident band 30 to the spout closure 25. As is inherently shown in FIGS. 1, 2, 5 and 6, dimples 44 can break the frangible elements 29 by either axial or rotational movement of the spout closure 25 relative to the pour spout 7.
Referring to FIGS. 1, 2, 3 and 6 of the drawings, the tamper evident band 15 has a plurality of circumferentially spaced elevated areas 35 each of which is positioned between adjacent frangible elements 14. The elevated areas 35 extend upwardly from the tamper evident band 15 in spaced relation to the lower edge of the depending annular flange 13 of the resealable closure 10 and provide selective support of the tamper evident band 15 to resist vertical movement imparted by the deflection of the tamper evident band 15 during insertion on the bottle neck 18 thereby protecting the frangible elements 14 during assembly.
Referring to FIGS. 1, 2 and 7, depending annular flange 13 has inwardly extending spiral threads 36 depending from its interior annular surface 13A. As shown in FIG. 1, these threads 36 may be configured as a series of interrupted segments, or alternately as a continuous spiral ridge as shown in FIG. 2. Each of the threads 36 is aligned in spaced vertical relation to one another thereby defining spaced parallel thread pairs extending about at least a portion of the interior annular surface 13A and terminating adjacent the top perimeter edge of said annular depending skirt 13. Spiral threads 36 are registerable with spiral threads 37 extending outwardly from the exterior of the neck portion 18, best seen in FIG. 7 of the drawings. Referring back to FIGS. 1 and 2 of the drawings, the relative positioning of spiral threads 36 and the projections 16 on the tamper evident band 15 can be seen to be in a circumferentially spaced overlapping relationship imparting offsetting points of engagement with the respective registering counter parts of the locking annular flange 17 on the bottle neck 18.
A first annular depending sealing flange 38 extends downwardly from the closure top portion 12 in spaced relation to the depending annular skirt 13. A second sealing flange 39 extends angularly inwardly from said top portion 12 adjacent said first sealing flange 38 thereby defining a multiple sealing configuration against the neck portion 18 of the bottle during use.
Referring to FIG. 6 of the drawings, the push pull closure 10 may be seen in assembled condition as hereinbefore described in FIGS. 1 and 2 illustrating an outside rib surface 40 on the depending annular flange 13.
To remove the push pull closure cap 10 from the bottle neck 18, rotation of the cap 10 is required which will accordingly engage the respective registering spiral thread 36 and 37 moving the push pull closure 10 upwardly, breaking the frangible elements 14 connecting the tamper evident ring 15 from depending annular flange 13 thereby leaving projections 16 below the locking flange 17 on the bottle neck portion 18 as will be well understood by those skilled in the art.
While presently preferred embodiments of the invention have been shown and described in particularity, the invention may be otherwise embodied within the scope of the appended claims.
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A resealable push-pull pour spout closure having an annular secondary closure with a central opening through which a plug is adapted to engage to close a container. The central opening is defined by an annular wall having at least one internally extending annular flange. The diameter of the central opening is substantially the same as that of the plug. The plug takes the form of a circular closure disk having an integrally molded depending annular skirt projecting from the periphery of the disk that attaches to angularly extending legs that connect the plug to the spout thereby defining a hollow cavity for the plug interior and increasing the structural flexibility of the plug. The annular seal flange projects radially into opening for form fitting engagement with the plug to substantially eliminate any leakage when the plug is positioned in the central opening.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to an impact energy absorbing structure which is used to absorb impact energy on the heads of passengers during collisions in vehicles, for example.
[0003] 2. Related Background Art
[0004] In order to ensure higher levels of passenger protection in the interior of vehicles such as automobiles, the recent trend has been toward the establishment of increasingly stringent standards regarding passenger safety measures and the like. In the United States, in particular, the Federal Motor Vehicle Safety Standards have been strengthened (FMVSS 201U), resulting in more stringent regulations regarding measures for protecting passenger heads. In FMVSS 201U, dummy heads (mass 4.54 kg) referred to as free motion headforms (FMH) are used as the colliding object, which is caused to collide on an interior part (impact energy absorbing structure) at 24 km/h, and the total acceleration a (t) at the FMH center of gravity is measured.
[0005] [0005]FIG. 1 illustrates an image from such an imact test, showing a schematic example of the shape of such an impact energy absorbing structure. FIG. 2 illustrates an image of the deformation characteristics of the structure during the imact test, where the headform acceleration is shown relative to the deformation of the structure. In the figure, the dashed line shows the results obtained with a conventional structure, where the acceleration is greater in the second half than in the first half of deformation. Because the product of the headform acceleration and the structure deformation expresses the collision energy (per kilogram) absorbed by the structure, the distribution of absorbed energy is greater in the second half than in the first half.
[0006] In this test, the total acceleration a(t) measured from a sensor is treated with Equations (5) and (6), giving HIC(d). HIC(d) is stipulated at no more than 1000 in FMVSS 201U.
HIC = MAX { [ 1 ( t 2 - t 1 ) ∫ t 1 t 2 a t ] 25 ( t 2 - t 1 ) } ( t 2 - t 1 ≤ 36 msec ) ( 5 ) HIC ( d ) = 0.75446 × HIC + 166.4 < 1000 ( 6 )
[0007] The terms in brackets in Equation (5) express the mean, between t 1 and t 2 , of the total acceleration measured by a triaxial accelerometer sensor, and HIC is the standard for assessing passenger head protection performance.
[0008] To study what type of structure will permit the HIC(d) to be minimized, most studies have thus far been based on the time-acceleration behavior of the colliding object. As illustrated by the dash-dot line in FIG. 2, case in which the time-acceleration behavior is in the form of a rectangular wave, that is, cases in which the impact absorption energy is uniformly distributed over time (and thus uniformly distributed over deformation), are reportedly the most effective. As a result, a major issue in the design of actual products has been how to make the deformation behavior (time-acceleration behavior of colliding object) more closely resemble a rectangular wave.
SUMMARY OF THE INVENTION
[0009] There is a trend toward stronger automobile safety standards in the US, as noted above, as well as a desire for greater safety in various other countries. Some vehicle interior parts with which the heads of passengers more likely collide should therefore function to absorb impact energy efficiently, such as roof side garnishes covering roof side rails or pillar garnishes covering various pillars inside vehicles such as the front, center, and rear pillars. On the other hand, such interior parts should be structured to efficiently absorb impact energy with low deformation in order to ensure greater space inside the vehicle. There is thus a need to develop impact energy absorbing structures which meet the above standards while preserving the most space possible in the vehicle.
[0010] In view of the foregoing, an object of the present invention is to provide an impact energy absorbing structure capable of efficiently absorbing kinetic energy during collision to alleviate the impact to passenger heads, in particular, while preserving the space inside vehicles. It is particularly an object of the present invention to provide an impact energy absorbing structure with even better impact energy absorbing properties than impact energy absorbing structures having rectangular wave deformation behavior (time-acceleration behavior of the colliding object) which have conventionally been considered ideal.
[0011] For achieving such object, the impact energy absorbing structure of this invention is characterized in that when a certain colliding object collides with said impact energy absorbing structure at a certain velocity, the following Formula (1) is satisfied by the relationship between dimensionless displacement D, where the deformation of the impact energy absorbing structure is normalized by the permissible deformation, and the dimensionless energy E, where the kinetic energy absorbed by the impact energy absorbing structure is normalized by the kinetic energy of the colliding object prior to collision.
E>D (1)
[0012] This makes it possible to provide an impact energy absorbing structure that is capable of efficiently absorbing kinetic energy during collision to alleviate the impact to passenger heads in particular while preserving space inside the vehicle, and that also has performance with a better impact energy absorbing pattern than the rectangular wave form which has conventionally been considered ideal. Although any material such as a resin, metal, or ceramic can be used for the material of the impact energy absorbing structure, resins are preferred because of advantages such as good formability, light weight, and ease of mass production.
[0013] Also the impact energy absorbing structure of this invention preferably comprises a substrate; an impact receiving member disposed parallel to the substrate; and a plurality of impact energy absorbing members that are disposed between the substrate and the impact receiving member, that deform while exerting repulsion on the colliding object, and that break when the critical deformation level is reached, wherein the critical deformation levels of each of the impact energy absorbing members are established stepwise within said permissible deformation range, and the repulsion of each of the impact energy absorbing members is set so as to meet the relationship between the dimensionless displacement D and dimensionless energy E defined in Formula (1). By differentiating properties of dimensionless energy (absorbed kinetic energy) relative to the dimensionless displacement of the aforementioned impact energy absorbing structure, the properties of dimensionless repulsion (load) relative to the dimensionless displacement of the impact energy absorbing structure can be found. The aforementioned structure makes it possible to easily produce an optimal model (model in which HIC(d) is minimized, with low permissible deformation) represented by such properties. That is, because dimensionless displacement is used as a parameter instead of time, the discrete values of such dimensionless displacement can correspond to the critical deformation of the impact energy absorbing members. Because the dimensionless repulsion is treated as a value, it can correspond to the synthetic repulsion of impact energy absorbing members that are not broken up, thereby making it possible to provide an impact energy absorbing structure with which an optimal model is readily realized.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] [0014]FIG. 1 shows an image in an impact test;
[0015] [0015]FIG. 2 is a graph of the impact energy absorbing properties of an impact energy absorbing structure;
[0016] [0016]FIG. 3 illustrates a kinetic model for analyzing the deformation process during impact energy absorption;
[0017] [0017]FIG. 4 is a graph showing the pattern of energy absorption during collision;
[0018] [0018]FIG. 5 is a graph showing deformation behavior with minimum HIC(d) in the case of 10 mm permissible deformation;
[0019] [0019]FIG. 6 is a graph showing deformation behavior with minimum HIC(d) in the case of 13 mm permissible deformation;
[0020] [0020]FIG. 7 is a graph showing deformation behavior with minimum HIC(d) in the case of 15 mm permissible deformation;
[0021] [0021]FIG. 8 is a graph showing deformation behavior with minimum HIC(d) in the case of 20 mm permissible deformation;
[0022] [0022]FIG. 9 is a graph showing deformation behavior with minimum HIC(d) in the case of 30 mm permissible deformation;
[0023] [0023]FIG. 10 is a graph showing deformation behavior with minimum HIC(d) in the case of 60 mm permissible deformation;
[0024] [0024]FIG. 11 is a graph comparing the HIC(d) values found in the patterns of deformation behavior in FIGS. 5 through 10 compared to a conventional example;
[0025] [0025]FIG. 12 is a graph showing the relationship between dimensionless kinetic energy and dimensionless deformation in the case of 10 mm permissible deformation;
[0026] [0026]FIG. 13 is a graph showing the relationship between dimensionless kinetic energy and dimensionless deformation in the case of 13 mm permissible deformation;
[0027] [0027]FIG. 14 is a graph showing the relationship between dimensionless kinetic energy and dimensionless deformation in the case of 15 mm permissible deformation;
[0028] [0028]FIG. 15 is a graph showing the relationship between dimensionless kinetic energy and dimensionless deformation in the case of 20 mm permissible deformation;
[0029] [0029]FIG. 16 is a graph showing the relationship between dimensionless kinetic energy and dimensionless deformation in the case of 30 mm permissible deformation;
[0030] [0030]FIG. 17 is a graph showing the relationship between dimensionless kinetic energy and dimensionless deformation in the case of 60 mm permissible deformation;
[0031] [0031]FIG. 18 is a graph showing the relationship between dimensionless kinetic energy and dimensionless deformation in FIGS. 5 through 10 compared to a rectangular wave form;
[0032] [0032]FIG. 19 is a graph illustrating the relationship between a characteristic curve and an approximation curve;
[0033] [0033]FIG. 20 is an oblique view of a specific example of an impact energy absorbing structure having the desired properties;
[0034] [0034]FIG. 21 illustrates elements of the impact energy absorbing structure in FIG. 20;
[0035] [0035]FIGS. 22A through 22D illustrate the process of the deformation of the impact energy absorbing structure in FIG. 20;
[0036] [0036]FIG. 23 illustrates another example of an element of the impact energy absorbing structure; and
[0037] [0037]FIG. 24A illustrates another example of an element of the impact energy absorbing structure, and FIG. 24B illustrates an example of an impact energy absorbing structure using such an element.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0038] Embodiments of the invention will be described below with reference to the drawings. The background leading to the concept of the impact energy absorbing structure of the invention will be described first. As already noted, HIC(d) is represented by Formulas (5) and (6). Formula (5) represents the maximum mean for total acceleration (absolute value for acceleration, magnitude of acceleration vector) in the deformation process (t 2 −t 1 ) where the interval (t 2 −t 1 ) is no more than 36 msec. During actual tests, the deformation behavior of the structure is ascertained in the form of the acceleration value relative to the deformation, for example, and this value can be calculated based thereon, but even in those cases, calculations are still required to a certain extent.
HIC = MAX { [ 1 ( t 2 - t 1 ) ∫ t 1 t 2 a t ] 25 ( t 2 - t 1 ) } ( t 2 - t 1 ≤ 36 msec ) ( 5 ) HIC ( d ) = 0.75446 × HIC + 166.4 < 1000 ( 6 )
[0039] The inventors attempted to find the structure of an impact energy absorbing structure which would provide a low HIC(d) while ensuring greater interior space by means of computer-aided optimization. Variables expressing the deformation behavior of various structures were thus given as parameters (design variables) to a computer in an attempt to use a certain kinetic model in order to calculate the process of the deformation of these structures. Although continuous functions can be treated in terms of the model, considering the complexity of the calculation itself of the HIC(d), it would be desirable to produce a simplified model for more efficient calculations.
[0040] The inventors therefore introduced the concept of deformation intervals, where the deformation behavior of a structure is divided into intervals, and adopted a method by which the continuous deformation method is simulated by means of such discontinuous deformation intervals. More specifically, the process from the initial deformation of the structure to the permissible deformation S is evenly divided into deformation intervals of equivalent deformation (Δx=S/M, where Δx: divided intervals, M: number of divisions), and the acceleration is assumed to be constant over each of the divided intervals. A model is produced by noting how much of the kinetic energy of the colliding object is absorbed by the structure during these intervals.
[0041] This will be illustrated with reference to FIGS. 3 and 4.
[0042] (1) The initial kinetic energy E 0 of the colliding object is first calculated based on the mass m (4.54 kg) of the colliding object and the collision velocity v 0 (24 km/h).
[0043] (2) The kinetic energy E ab1 absorbed by the structure from the colliding object in the first interval is treated as α 1 times the initial kinetic energy E 0 (0≦α 1 ≦1). Thus, the absorbed kinetic energy E ab1 in the first interval is given as:
E ab1 = α 1 E 0 = m v 1 2 / 2 - m v 0 2 / 2 = ( v 1 - v 0 ) ( v 1 + v 0 ) m / 2 = [ ( v 1 - v 0 ) / Δ t ] m [ Δ t ( v 1 + v 0 ) / 2 ] = a 1 m Δ x ( 7 )
[0044] Here, v 1 is the velocity of the colliding object at the point in time where the initial interval is completed. Accordingly, the acceleration a 1 at that interval is α 1 ·E 0 /(mΔx), and the kinetic energy E 1 of the colliding object having passed through the interval is (1−α 1 )·E 0 .
[0045] (3) Similarly, the kinetic energy E abn absorbed at the nth interval is given as:
E abn =α n E n−1 =a n mΔx (8)
[0046] The acceleration a n at that interval is α n ·E n−1 /(mΔx), and the kinetic energy E n of the colliding object having passed through the interval is given as (1−α n )·E n−1 . Because the energy (α n ·E n−1 ) absorbed by the structure at the nth interval is a n (mΔx), it is proportional to the acceleration a n at that interval.
[0047] (4) It is only in the final Mth interval α M =1.0, in consideration of the fact that all the kinetic energy is consumed as a result of bottoming out.
[0048] (5) The time Δt n (Δt n =(v n −v n−1 /a n [a n ≠0], Δt n =Δx/V n−1 [a n =0]) it takes for the colliding object to pass through each interval is obtained from the velocities V n−1 and V n before and after the interval through which the colliding object passes, and the acceleration a n during that interval.
[0049] Next, the pattern of deformation with minimized HIC(d) defined in Equations (5) and (6) is determined using computer-aided optimization based on the simplified kinetic model of collision described above. In the present embodiment, optimization is achieved using α n (0≦α n ≦1:n=1, 2, . . . , M) as the design variable at each interval and the HIC(d) obtained from a (t) as the evaluation function. “iSIGHT” (ver 5.1) of Engineous Software, Inc. can be used as optimization software, and simulated annealing can be used as the optimization method. M, which is the number of interval divisions, is determined according to the balance between the necessary accuracy and the computing load, but is preferably about 4≦M≦20. As the result of the calculations, the HIC(d) value (minimum value) is output in combination with α n (0≦α n ≦1:n=1, 2, . . . , M) giving the minimum value for HIC(d).
EXAMPLES
[0050] The patterns of α n (0≦α n ≦1:n=1, 2, . . . , M) with minimum HIC(d) were actually determined for various permissible deformation levels S by the method described above. M=10 was established using “iSIGHT” (ver 5.1) by Engineous Software, Inc. as the optimization software and simulated annealing as the optimization method. The permissible deformation S serving as a condition was suitably spread out between 10 and 60 mm.
[0051] [0051]FIGS. 5 through 10 show the deformation behavior at the various permissible deformation levels S calculated on the basis of the patterns of α n (0≦α n ≦1:n=1, 2, . . . , M) giving minimum values. In these figures, the horizontal axis is the dimensionless deformation, which is obtained by dividing the deformation by the permissible deformation S, and the vertical axis is the dimensionless acceleration, which is obtained by dividing the acceleration of each deformation interval by the maximum acceleration. Because the product of the acceleration and deformation is proportional to the energy absorbed by the structure as described above, these figures show the energy absorption patterns of the structures.
[0052] The figures show that the minimum HIC(d) is given not by the rectangular wave indicated by the dash-dot line in FIG. 2, which has conventionally been considered ideal, but rather, as shown by the pattern outlined by the solid line C in FIG. 2, in a wave form characterized by maximum acceleration soon after collision and subsequently diminishing acceleration. The common structure shown by the dashed line in FIG. 2 also differs in that the acceleration during deformation is greater in the first half than the second half of the deformation process. In FIG. 11, the minimum value for HIC(d) given by the aforementioned pattern of deformation behavior is compared to that of the rectangular wave form.
[0053] The requirements for structures having good impact energy absorbing properties were then determined based on the features common to wave form patterns at varying permissible deformation levels having such an optimized pattern. In the following analysis, the dimensionless kinetic energy, which was obtained by dividing the kinetic energy(=energy absorbed by the structure) by the kinetic energy of the colliding object prior to collision, was used instead of the acceleration of the colliding object for the vertical axis. FIGS. 12 through 17 are graphs cumulatively showing the absorption energy (optimal pattern lines) relative to the dimensionless deformation at each permissible deformation level S, and these are summarized in FIG. 18. Table 1 gives these dimensionless absorption energy values.
TABLE 1 Dimensionless PERMISSIBLE DEFORMATION (mm) Deformation D 10 13 15 20 30 60 0 0.000 0.000 0.000 0.000 0.000 0.000 0.1 0.280 0.136 0.246 0.260 0.156 0.278 0.2 0.372 0.243 0.293 0.399 0.273 0.397 0.3 0.386 0.561 0.518 0.490 0.517 0.495 0.4 0.585 0.607 0.620 0.514 0.548 0.570 0.5 0.696 0.671 0.662 0.676 0.600 0.688 0.6 0.771 0.823 0.675 0.768 0.744 0.697 0.7 0.780 0.830 0.708 0.825 0.815 0.834 0.8 0.869 0.906 0.887 0.878 0.891 0.870 0.9 0.953 0.981 0.950 0.953 0.942 0.948 1.0 1.000 1.000 1.000 1.000 1.000 1.000
[0054] [0054]FIG. 18 shows the pattern of a rectangular wave form. The cumulative absorption energy properties in the case of a rectangular wave form are represented by a straight line
E=D (9)
[0055] where E is the dimensionless energy of the vertical axis, and D is the dimensionless deformation of the horizontal axis. As indicated in the figure, the optimal lines (broken lines) are in the arc-shaped region above the straight line E=D. The curve encompassing in the upper side the group of absorption pattern lines giving the minimum HIC(d), is defined as:
E=f ( D )=0.3 D 0.3 +0.7[1−(1 −D )] 2 ] (10)
[0056] A more detailed discussion is given below.
[0057] A closer look at FIG. 18 reveals that the group of optimal pattern lines (broken lines) resembles a curve that is obtained by uniformly expanding the straight line (9) toward the curve (10). The function g (D) expressing such a curve group is given by the following equation.
E=g ( D )=(1−β) D+βf ( D ) (11)
[0058] When β=0, g(D)=D, in other words, the straight line (9), and when β=1, g(D)=f(D), in other words, the curve (10). When 0<β<1, the curve group is in the region between straight line (9) and curve (10), and when β<1, the curve group is above curve (10).
[0059] HIC(d) was calculated for cases where β was suitably varied in the region 0<β, that is, the region higher than straight line (9). The results are given in Table 2. Although the numerical values themselves for HIC(d) in the curve group (11) vary depending on the permissible deformation, the change tends to be the same. That is, the values gradually become lower the greater than 0 that β becomes, resulting in a minimum of around β=0.5 to 0.75, and the values then gradually increase. The values are better than in the case of a rectangular wave at all permissible deformation levels in the range 0<β≦1.06. In the range 1.07≦β≦1.19, the values are better than the rectangular wave form at some of the permissible deformation levels.
TABLE 2 PERMISSIBLE DEFORMATION (mm) 10 13 15 20 30 60 MINIMUM HIC(d) AT 1270 1010 799 575 405 246 VARYING PERMISSIBLE DEFORMATION LEVELS E = D (β = 0) 1920 1350 1120 785 503 285 β = 0.01 1910 1340 1110 782 501 285 β = 0.1 1780 1290 1070 749 484 279 β = 0.25 1690 1210 1000 711 461 271 β = 0.5 1470 1050 869 629 413 252 β = 0.75 1430 1070 871 622 408 253 E = 0.3D 0.3 + 0.7 1680 1280 1020 724 456 270 [1 − (1 − D) 2 ] (β = 1.0) β = 1.01 1680 1290 1030 741 457 272 β = 1.06 1750 1340 1070 767 472 277 β = 1.07 1770 1350 1070 772 474 278 β = 1.08 1780 1360 1080 779 477 279 β = 1.1 1800 1390 1100 789 481 280 β = 1.19 1910 1500 1180 842 509 290 β = 1.195 1920 1510 1180 845 510 291
[0060] As indicated above, the curve group (11) giving good HIC(d) are in the range 0<β≦1.19 (such curves are referred to below as the good curves). However it is assumed that good properties may be expected even in cases not completely consistent with these good curves. That is because the optimal pattern lines such as those in FIG. 18 are not in fact necessarily found in Equation (11) for the good curves. The extent to which the optimal pattern lines deviate from the good curves should be within a permissible range. The extent of this deviation was then studied.
[0061] An approximation curve, that is, a good curve E−g(D) most closely resembling the various optimal pattern lines (these are expressed as E=h(D)) in FIG. 18, was determined by the least squares method. The results are given in Table 3 as the values for β in the approximation curve. The deviation index between the approximation curve and the broken line E=h(D) was then determined by the method shown in FIG. 19. That is, the sum S 1 of the area of the regions divided by curve E=g(D) and the optimal pattern line E=h(D) was determined, the area S 2 of the region divided by curves E=f(D) and E=D was determined, and the “deviation index” R 1 was defined by the ratio between the two (=S 1 /S 2 ). The results are similarly shown in Table 3. According to this, the deviation R 1 is considerably high when the permissible deformation is low, but as a whole, R 1 <33% is considered the permissible range.
TABLE 3 PERMISSIBLE DEFORMATION (mm) 10 13 15 20 30 60 β OF THE 0.377 0.339 0.453 0.342 0.491 0.342 APPROXIMATION CURVE DEVIATION R 1 0.332 0.711 0.546 0.169 0.212 0.255
[0062] Another method for determining the deviation (“deviation factor”) between the approximation curve and optimal line E=h(D) is to determine the maximum ratio between the absorption energy in the optimal patterns in Table 1 and the absorption energy of the approximation curve determined as described above. The former method gives an index of the deviation as a whole, whereas the deviation obtained in this case can be considered an index of local deviation. The results are given in Table 4. According to this, a deviation R 2 of −30%<R 2 <30% is considered a good range.
TABLE 4 Dimensionless PERMISSIBLE DEFORMATION (mm) Deformation D 10 13 15 20 30 60 0 (1.000) (1.000) (1.000) (1.000) (1.000) (1.000) 0.1 1.308 0.616 1.228 1.178 0.806 1.261 0.2 1.069 0.681 0.888 1.122 0.851 1.116 0.3 0.829 1.179 1.163 1.031 1.187 1.042 0.4 1.023 1.042 1.125 0.884 1.014 0.980 0.5 1.042 0.991 1.023 0.999 0.941 1.016 0.6 1.024 1.080 0.920 1.008 1.026 0.915 0.7 0.942 0.993 0.871 0.987 1.012 0.998 0.8 0.971 1.006 1.003 0.975 1.015 0.966 0.9 1.001 1.027 1.005 0.997 1.000 0.992 1.0 1.000 1.000 1.000 1.000 1.000 1.000 MAXIMUM 1.308 1.179 1.228 1.178 1.187 1.261 VALUE MINIMUM 0.829 0.616 0.871 0.884 0.806 0.915 VALUE
[0063] Below is a description of a method for actually producing an impact energy absorbing structure which has been designed by stipulating the profile of the absorption kinetic energy per unit deformation as described above. In this example, the impact energy absorbing structure that is produced has a permissible deformation of 30 mm, with an impact energy absorption properties pattern represented by a good curve in which β=0.5. 10 deformation intervals are set in this case. The absorption energy at each deformation interval of the impact energy absorbing structure having such an impact energy absorbing pattern can be calculated from the good curve in which β=0.5, as in Table 5. Thus, because
E abn =a n mΔx=f n Δx (12)
[0064] from Equation (8), the absorption energy can be calculated as the mean repulsion f n at the subject interval, based on this equation. The results are given in Table 5. The “ratio between structures breaking at the subject interval and structures at the interval 10” in Table 5 means the proportion of the repulsion of the impact energy absorbing members breaking at the interval relative to the synthetic repulsion of the total impact energy absorbing members left over the interval.
TABLE 5 DIMENSIONLESS RATIO BETWEEN ENERGY STRUCTURES ABSORBED BREAKING AT DEFORMATION BEFORE DIMENSIONLESS THE SUBJECT AT THE END THE END ENERGY ENERGY MEAN INTERVAL AND OF THE OF THE ABSORBED AT ABSORBED AT REPULSION OF STRUCTURES INTERVAL INTERVAL THE INTERVAL THE INTERVAL THE INTERVAL AT INTERVAL INTERVAL (mm) (−) (−) (J) (N) 10 (−) 1 3 0.191678 0.191678 103.1833 34394.44 1.114051 2 6 0.318555 0.126877 68.29988 22766.63 0.213270 3 9 0.433027 0.114472 61.62192 20540.64 0.164180 4 12 0.537949 0.104922 56.48109 18827.03 0.146693 5 15 0.634338 0.096389 51.88781 17295.94 0.138213 6 18 0.722688 0.08835 47.56004 15853.35 0.133388 7 21 0.803279 0.080591 43.38337 14461.12 0.130352 8 24 0.876287 0.073009 39.30176 13100.59 0.128304 9 27 0.941833 0.065546 35.28426 11761.42 0.126852 10 30 1 0.058167 31.31225 10437.42 1
[0065] In such an impact energy absorbing structure having such a mean repulsion f n distribution at each interval, the mean repulsion f 1 is in force at the first interval 1, the mean repulsion f 2 is in force at the next interval 2, and the mean repulsion f n is in force at interval n. Since ordinarily f n ≠f n−1 , it is necessary to adjust the quantity of the structure at stages where the interval is changed. In this example, because the mean repulsion becomes lower (uniformly diminishes) as deformation progresses, the quantity of the structure involved in the deformation gradually diminishes.
[0066] [0066]FIG. 20 illustrates an embodiment of the impact energy absorbing structure of the invention for realizing this. In this case, a plurality of tensile structural elements for which the mean repulsion and break-down deformation can be adjusted to the desired level, such as that shown in FIG. 21, are used for each deformation interval. That is, tensile structural elements with the breaking deformation set to break down after having passed through each deformation interval are arranged in rows so that each element independently undergoes tensile deformation. Accordingly, the breaking deformation of each structural element is set so that the elements would break at every deformation interval breadth Δx. The material for the structural elements was selected and/or the cross section area was set so that the remaining parts involved in deformation at each deformation interval were capable of bearing the mean repulsion required for the deformation intervals.
[0067] Ways to ensure that the structural elements have such different breaking deformation levels include selecting a suitable material, changing the length of the material, or both. Ways to set the mean repulsion include selecting a suitable material, changing the cross section area, or both. In the illustrated example, structural elements A through J are arranged in rows. They are composed by attaching channel members having an L-shaped cross section to the edges of the structural members, where the other edge of one channel member is joined to a substrate, and the other edge of the other channel member extends toward the colliding object.
[0068] In this example, the material of the structural members was the same. The breaking deformation was therefore adjusted by the length in the direction of collision (not shown in figure; same length), and the mean repulsion was adjusted by the cross section area. In this example, the cross section area was adjusted by varying the depth of the structural elements as shown in FIG. 20. In such an impact energy absorbing structure, as illustrated in FIGS. 22A through 22D, the structural elements A through J break in sequence as the deformation progresses one deformation interval breadth Δx at a time, modifying the mean repulsion at each deformation interval, and thereby giving the intended impact energy absorbing properties pattern.
[0069] Tensile structural elements can be used in such an impact energy absorbing structure to allow the timing involved in the deformation of the structural elements to be set as desired. The breaking deformation and mean repulsion can be independently set by changing the material or dimensions, thereby allowing the desired impact energy absorbing properties pattern to be brought about. The aforementioned example was of a case in which the absorption energy, that is, the mean repulsion, in the impact energy absorbing properties pattern diminished uniformly, but for patterns which include cases of increasing repulsion, the channel members should be shortened in the direction of collision, for example, so that some of the structural elements involved in the deformation will deform more slowly than others.
[0070] [0070]FIG. 23, which is another example of a structural element, illustrates a torsional structural element which exploits the torsional deformation of the structural member. This may involve fixing one end of a cylindrical structural member, for example, to a substrate, and attaching a handle to the other end, allowing the mean torque and breaking angle to be set as desired by selecting the material or shape/dimensions. In FIGS. 24A and 24B, a plurality of structural elements comprising both ends of a sheet formed in a ring around the structural member are coaxially disposed on a substrate, and conical rigid elements are coaxially disposed on the colliding object side, where the structural members undergo tensile deformation and break in sequence as the ring widens. Because the parts are coaxially disposed, the structure can be more compact than that illustrated in FIG. 21.
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An object of the invention is to provide an impact energy absorbing structure in the form of resin moldings such as interior components of automobiles and other impact energy absorbing structures, with better impact properties, particularly the performance in absorbing impact energy to passenger heads. The invention relates to an impact energy absorbing structure for absorbing the kinetic energy of a colliding object by means of its own deformation, wherein when a certain colliding object collides with the impact energy absorbing structure at a certain velocity, the relationship between dimensionless displacement D, where the deformation of the impact energy absorbing structure is normalized by the permissible deformation, and the dimensionless energy E, where the kinetic energy absorbed by the impact energy absorbing structure is normalized by the kinetic energy of the colliding object prior to collision, meets E>D.
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CROSS REFERENCE TO RELATED APPLICATIONS
The present invention relates to copending U.S. application Ser. No. 08/153,623 entitled Improved Climbing Net, filed in the name of Rexroad et al. on Nov. 17, 1993 and also relates to U.S. application Ser. No.: 08/414,185 entitled Hollow Braid Net and Method of Making, filed Mar. 31, 1995, now U.S. Pat. No. 5,622,094 and further relates to U.S. application Ser. No. 08/557,851, now U.S. Pat. No. 5,752,459 entitled Net With Flattened surface Members Connected At Sewn Intersections.
CROSS REFERENCE TO RELATED APPLICATIONS
The present invention relates to copending U.S. application Ser. No. 08/153,623 entitled Improved Climbing Net, filed in the name of Rexroad et al. on Nov. 17, 1993 and also relates to U.S. application Ser. No.: 08/414,185 entitled Hollow Braid Net and Method of Making, filed Mar. 31, 1995, now U.S. Pat. No. 5,622,094 and further relates to U.S. application Ser. No. 08/557,851, now U.S. Pat. No. 5,752,459 entitled Net With Flattened surface Members Connected At Sewn Intersections.
BACKGROUND OF THE INVENTION
The present invention relates to a material used in the formation of nets, and is more particularly related to an improvement in such material wherein the material has improved stretch resistant characteristics allowing a net constructed therefrom to be a more stable device yet still provide a nonabrasive outer surface.
Conventional net constructions have had application for use as climbing nets and/or as nets for recreational purposes, such as found in playscapes or the like for children. The perpendicularly intersecting lengths of cord or other continuous elongate members which connect at intersections generate a generally square mesh like structure. The squares, or other closed shapes of the mesh structure are used to grab, step, hold or otherwise provide a structural support for the individual who is using the device or the item which is being supported by the net structure. For example, in a net which is hung vertically for climbing purposes, downwardly applied forces are distributed both vertically and laterally through the net lattice. In addition to the force loading requirements of a net structure, it is also desirable to construct a net from a material which is of a nonabrasive construction so as to not scratch or abrade the exposed skin of the individual who is engaged with the net. This is most important in the application of the net where it is used for amusement purposes with children. As is set forth in copending U.S. application Ser. No. 08/153,624, entitled, Improved Climbing Net, it is disclosed in that application to use a non-abrasive material in the net construction such as a multi-filament polypropylene ethylene copolymer which avoids problems with netting material which is abrasive to the touch. However, such netting material has problems inherent to the twisted construction of each of the elongated members. That is, in order for the ends of the lengths of cordage to terminate, the lengths are usually heated in order to melt the plastic and prevent unraveling of the multi-filaments. These heated end portions tend to be sharp and leave hard knobs and defeat the non-abrasive character of the over all netting. Also, the twisted cylindrical shape is harder to grasp by a child than a flattened design.
In copending U.S. application Ser. No. 08/557,851, entitled Net With Flattened surface Members Connected At Sewn Intersections, it is disclosed to employ a net having elongated members which are of a tape-like configuration. That is, the net is formed from a flattened braided multi-filament material which is easier to grab and hold by the young hand of a child as opposed to the larger more rigid cylindrical shape of a twisted rope. The problem experienced with such braided tape-like elongated cordage members, and to some degree with the cylindrically twisted type rope, is that both tend to allow slack to prevail when loaded. In the case of the cylindrical twisted rope members, the twisted member tends to want to untwist and give up slack, and hence stretch. Likewise, the braid configuration has a loosely fitted braid intersecting matrix which when loaded tightens on itself thereby also giving up slack and stretching.
Accordingly, it is an object of the present invention to provide net cordage material which is of a tape-like construction and formed from a material nonabrasive to the touch by a human hand.
It is yet a further object of the invention to provide a net of the aforementioned type wherein the netting component is formed from a compound material defined by a smooth piercable unabrasive outer sheathing enclosing within a strengthening web core.
It is still a further object of the present invention to provide a net cord of the aforementioned type wherein the outer sheathing of the cord is formed from a material which is color fast in resistance to ultraviolet radiation.
SUMMARY OF THE INVENTION
The invention resides in an improved cordage member for use in net construction. The flexible member for netting comprises a sheathing having a generally elongate extent extending with a longitudinal axis, the sheathing having a generally rectangular shape as seen in end view and being generally defined by first and second spaced long sides extending parallel to one another and by first and second short sides each connected to and extending generally perpendicularly to the first and second long sides and extending parallel to one another to define therewithin a hollow internal confine therewithin. An elongate core member having a generally tape-like configuration located within the hollow internal confine of the sheathing so that the elongate extent of the core member extends coextensively with the elongate extent of the sheathing member as taken along the longitudinal axis. A means is provided for interconnecting the sheathing to the core member.
Ideally, the sheathing is a hollow braided member which is capable of being pierced through any one of the long and short sides and the means for interconnecting the sheathing to the core member core member being stitching. Also, the core member is preferably formed from a nylon web and the sheathing member being formed from a braided multi-filament material and the sheathing multi-filament material being formed from a color-fast polypropylene material.
Preferably, the member is used in a lattice of a plurality of the members disposed coplanar with one another and intersecting at predetermined angles and being box stitched at the intersections thereof and the intersecting members define weft and warp members of the lattice, each of the weft and warp members having free end portions which connect to a border member enclosing the lattice.
In one embodiment, the border member is comprised of an endless loop of defined by one of the plurality of the members with the free ends of the one of the plurality of the members being intertucked with one another and box stitched thereto. The weft and warp members may interconnect by cross piercing each other at nodes. The weft and warp members of the plurality of members may connect to the border such that the long side faces thereof are disposed parallel and generally coplanar with one another and the border member flat long sides being disposed perpendicularly to the plane which includes the weft and warp members.
Another aspect of the invention reside in providing a plurality of the members each having free end portions, the free end portion of one of the plurality of members piercing the sheathing of the other of the plurality of members in the vicinity of the free end portion thereof, and the free end portion of the one of the plurality of members piercing the sheathing of the other of the plurality of members in the vicinity of the free end portion thereof and each piercing portion being left within the internal hollow confine of the members and being stitched in place therein.
The invention also resides in a net comprising a plurality of generally flat elongated weft and warp members each having a generally rectangular shape as seen in end view and being generally defined by first and second spaced long sides extending parallel to one another and by first and second short sides each connected to and extending generally perpendicularly to the first and second long sides and extending parallel to one another; the weft and warp members connect to one another at intersections therebetween such that the long sides of each of the weft and warp members contact one another to effect a generally coplanar lattice of interconnecting weft and warp members. A border member is arranged about the intersecting weft and warp members and each of the weft and warp members having opposite free end which are connected to the border member. The border member has a generally rectangular shape as seen in end view and is generally defined by first and second spaced long sides extending parallel to one another and by first and second short sides each connected to and extending generally perpendicularly to the first and second long sides and extending parallel to one another, and the first and second long sides of the border member are disposed perpendicularly to the plane of the lattice of interconnecting weft and warp members.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partially fragmentary isometric view showing the improved cordage members in a net construction lattice which is of a planar configuration oriented perpendicularly to the border member.
FIG. 2 is a partially fragmentary plan view of the improved cordage members of the invention as used in a square single plane lattice configuration.
FIG. 3 is a top plan view of the intersection of a weft in a warp member of the lattice shown in FIGS. 1 and 2.
FIG. 4 is a fragmentary perspective view showing the improved cordage member apart from a constructed net.
FIG. 5 is a top plan view of a knotted intersection between a weft and a warp member in a lattice construction of a net.
FIG. 6 is an end to end splice using a cordage member of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 illustrates a net reference generally as 2. The net 2 is defined by a net lattice 3 and a border member 4,4'. The net lattice and the border member as disclosed herein are comprised of an improved flexible cordage member 1 which is illustrated separately as element 1 in FIG. 4. The lattice 3 is thus comprised of a plurality of weft members 6,6 extending in one direction and a plurality of warp members 8, 8 extending orthogonally thereto, each of which weft and warp members being each comprised of the improved cordage member 1. Furthermore, although the present disclosure seeks to describe the invention in its preferred embodiments, it is well within the purview of the invention to form a lattice by intersecting the weft and warp members at angles other than at the illustrated ninety degree orientation shown in the figures, particular with respect to the flattened sewn intersection of FIGS. 2 and 3, wherein the orientation of the weft and warp members can be easily fixed by sewing.
The weft and the warp members intersect and are connected with one another at nodes 10,10. The weft and warp members 6,6 and 8,8, respectively, interconnect with the border member at points 13,13, and, depending upon the type of net construction chosen, connect in different manners, which will be discussed in greater detail later. The weft, warp and border members taken together more importantly create rows and columns of boxes, or closed shapes, 12,12 arranged in a matrix to generate the illustrated grid-like pattern shown in FIGS. 1 and 2.
The border member 4,4' encloses an area defining the lattice 3 of the net 2. For purposes of illustration, it should be seen that the border member is said to be defined by four corner points identified as 14, 16, 18 and 20. Each of these corner points when taken consecutively in pairs define a first border section 22, extending between points 14 and 16, a second border section 24 extending between points 16 and 18, a third border section 26 extending between points 18 and 20 and a fourth border section 28 which extends between points 20 and 14.
In the embodiment of FIG. 1, the border 4 is itself comprised of a single length of the cordage 1 spliced end to end at a point 30 in the manner illustrated in FIG. 6. and is oriented perpendicularly to the plane P of the lattice 3. Alternatively, the border member 4' can be disposed in the plane P with the lattice 3, and may be made up of four separate pieces which are overlapped at the corners 14, 16 18 and 20, or, alternatively the border can be a single piece which is folded at a forty-five degree angle to make the right angle turn between, for example sections 22 and 24.
Referring now to FIG. 4, and to the detailed construction of the cordage member 1, it should be seen that the member 1 is a generally elongated member extending along a longitudinal axis AX and is comprised of an outer sheathing 30 defining a hollow inner confine 32, which as seen in front end view, is somewhat rectangular in shape. Disposed within the hollow confine 32 of the sheathing member 30 is a core member 34 which extends coextensively with the length of the sheathing member 30. In the illustrative embodiment of FIG. 4, the sheathing has been cut away to reveal the internal core member 34, but normally both members are coextensive with one another.
The sheathing member 30 has two generally parallel disposed long side faces 36 and 36 which extend parallel to the longitudinal axis LA of the member 1, and has short side faces 38,38 which are formed so as to be disposed perpendicularly to the long side faces 36,36. The sheathing member is in the preferred embodiment a 11/16" color-fast diamond braided multi-filament polypropylene hollow rope which is a commercially available part sold by Gulf Rope and Cordage, Inc. of Mobile, Ala. under part No. 30822-07-3311A. The core member 34 is a tape-like webbing which is manufactured by Elizabeth Webbing Mills Company, Inc., Roosevelt Avenue, Central Falls, R.I. as part No. 7650. The core member 34 preferably is a nylon webbing with a width of approximately 0.5 inch and having an average thickness of 0.065 inch. The core member 34 has a tinsel strength rating of approximately 1,620 lbs. Alternatively, the core member 34 may be selected as a product also commercially sold by Wellington Synthetic Fibers Inc. of Leesville, S.C. under product No. N215Z.
As illustrated in FIG. 3, the flattened configuration of the cordage members 1,1 allows a unique connection to be made between orthogonally disposed weft and warp members 6,6 and 8,8 through the intermediary of a stitch 40. That is, the weft and warp member connection illustrated in FIG. 3 is effected by laying one member 6 over the other 8 at a desired orientation, in this case at a ninety degree angle, and then and stitching the crossed members to one another by a box stitch 40. The box stitch 40 while not only effecting a connection between juxtaposed weft and warp members 6 and 8 further serves to fix the coaxially disposed core and sheathing members 30 and 34 in unity with one another. In this way, the sheathing 30 is maintained lengthwise in an almost a one to one positional correspondence with the corresponding length of the core member 34 disposed therewithin. As illustrated in FIG. 2, this sewn connection wherein members are layered one on the other and then stitched, also occurs at connections 13',13' between the border member 4' and respective ends of the weft and warp members 6,6 and 8,8.
Referring back to FIG. 1 and ahead to FIG. 6, it is a further object of the invention to use the improved cordage member 1 to form a continuous or endless loop making up the border member 4. The border member 4 as best illustrated in FIG. 6, has free ends each of which pierce the sheathing member 30 and extend into the confine 32 along the elongate dimension of the involved pierced member. Once each free end is tucked within the other in this manner, a box stitch 46 is made over the area of intersection to fix the intertucked free ends. For a further description of this end to end tuck type connection, reference may be had to copending U.S. application Ser. No. 08/557,851, entitled NET With Flattened surface Members Connected At Sewn Intersections.
As previously mentioned, the border member 4 in the embodiment of FIG. 1 is oriented such that the long flat side faces 36,36 thereof extend perpendicularly to the corresponding long sides faces 36,36 of the weft and warp members 6 and 8 which are stitched together in the illustrated manner of FIG. 3. The free end portions 42 and 44 of the weft and warp members connect to the border 4' by piercing into the border member through the innermost face 36 and each is thereafter pushed into the hollow confine 32 of the border member along the axial extent thereof. The length of the free end portions 42 and 44 of the weft and warp members which are received within the hollow confine of the border member is thereafter stitched at points 48,48 to terminate the respective free end portions of the weft and warp members therewithin. In this way, the net is free from exposed roughened edges of members which would otherwise connect to the border member 4 through normal splicing arrangements. It should be understood that each of the free end portions 42 and 44 of the weft and warp members undergoes a ninety degree twist between the plane P defined by the lattice of weft to warp members 6 and 8 and the respective connections to the border member 4 in order to orient the long flat faces 36,36 of the weft or warp members in parallel relation with the corresponding long faces 36,36 of the border member 4.
Referring now to FIG. 5, it should also be seen that the construction of the improved cordage members 1,1 further allows for weft and warp member 6,6 and 8,8 to connect with one another by a knotting, as opposed to a connection that is stitched. As illustrated in FIG. 5, weft member identified as 6a is caused to pierce the small side face 38a of the warp member 8a and pass into the hollow confine 32 thereof and generally perpendicularly through the member 8a and exit at the side 38b. In a like manner, the warp member 8a is caused to pierced the side 38b' of the weft member 6a and pass ninety degrees therethrough and exit side 38a'. It should be appreciate that the braided sheathing 30 which makes up the cordage member 1 is fully piercable and allows the piercing interconnections between the illustrated weft and warp members to occur. This is because the thickness and width profiles of the core members 34 are sufficiently small as to still allow room within the confine 32 for an inserted length of an intersecting weft or warp member. Thus, the internal construction of the cordage member 1 does not significantly increase the dimensions of the sheathing 30 from that which it is normally exhibits absent the core 34 disposed therein.
Accordingly, the invention has been described by way of illustration rather than limitation. For example, the core has been described in the illustrated embodiments as being comprised of a nylon material, however, the core may be made from a material such as polyester or polypropylene which is tightly enough formed to allow almost zero stretching. Also, while not specifically disclosed, it should be understood that the sheathing 30 can alternatively be formed from a braided nylon or polyester material, or the like. Additionally, while the invention has been described with the lattice 3 connecting to a border 4,4', it is well within the purview of the invention to used the improved cordage member 1 without a border, and instead to use other means of attaching the lattice to a frame or structure, such as, by looping the ends to effect such attachment.
The invention has thus been described in the preferred embodiment by way of illustration.
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A member for use in net construction comprises a sheathing with an internal core, the internal core has a very low stretch capacity and the outer sheathing has a much larger stretch capacity but allows intersplicing of crossing members within the lattice or between a border member comprised of such a material and the free end of the weft and warp members.
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This is a Division of application Ser. No. 08/040,916, filed Mar. 31, 1993 U.S. Pat. No. 5,377,143.
CROSS-REFERENCE TO RELATED APPLICATION
The present application is related to U.S. patent application Ser. No. 08/041,321, entitled "Multiplexing Sense Amplifier" filed of even date herewith by the inventor hereof, assigned to the assignee herein, and incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to the field of microelectronics and in particular to a method and apparatus for sensing signals from a memory array. Still more particularly, the present invention relates to a method and apparatus for selecting and sensing signals from a memory array.
2. Description of the Prior Art
Memories are devices that respond to operational orders, usually from a central processing unit (CPU) of a digital computer. A sense amplifier is typically employed to detect attenuated signals from a memory array. Two types of sense amplifiers are typically used: a static sense amplifier and a dynamic sense amplifier. Dynamic sense amplifiers are often used because they have low current consumption and the sense amplifiers are activated only when required to perform sensing functions.
Referring to FIG. 1, a memory array 100, a multiplexer 102, and a sense amplifier 104 are depicted in a configuration known to those skilled in the art. Memory array 100 contains a number of bit line pairs that may be accessed using word lines (not shown). Frequently in memory arrays, such as memory array 100, sense amplifier 104 is shared among many columns of the memory array. In addition, the data fed into sense amplifier 104 might be multiplexed between different blocks of columns within memory array 100. In the depicted example, left block 100a and right block 100b of memory array 100 share sense amplifier 104. Two pairs of data lines, LBT, LBC, RBT, and RBC originate from memory array 100 and are connected to multiplexer 102. Data lines LBT and LBC originate from left block 100a of memory in memory array 100; data lines RBT and RBC originate from right block 100b in memory array 100. Data lines LBT and LBC carry left block true and complement data signals respectively, while data lines RBT and RBC carry right block true and complement data signals respectively. Multiplexer 102 is used to select data from one pair of data lines and is connected to sense amplifier 104. Sense amplifier 104 may include a number of different stages.
Referring next to FIG. 2, sense amplifier 104 may include the following stages: level shifter 106, current mirror 108, and p-channel cross-coupled amplifier 110. A level shifter is typically employed to shift the voltage of the multiplexed signals in order to optimize the other stages of the sense amplifier. Typically, level shifter 106 is used to adjust the voltage of the signal selected by multiplexer 102 in order to optimize the performance of the other stages within sense amplifier 104. Sense amplifier 104 is employed to detect signals, in lines MUXC and MUXT, selected by multiplexer 102 from memory array 100. Typically, sense amplifier 104 includes p-channel cross-coupled amplifier 110 with a high common-mode rejection in order to reject picked-up interference due to cross-talk from other parts of the system.
With reference now to FIG. 3, a schematic diagram of a known multiplexer is illustrated. The multiplexer is constructed with transistors MA-MM. The transistors are p-channel metal-oxide semiconductor field effect transistors (MOSFETs). Multiplexer 102 is powered by connecting transistors ME, MG, MH, MI, MJ, and ML to power supply VCC. Points 111, 113, and 115 are points at which an equalization signal is applied to multiplexer 102.
Data from data line LBT is fed into the multiplexer 102 at input point 112; data from the data line LBC is fed into multiplexer 102 at input point 114; data from data line RBT is fed into multiplexer 102 at input point 116; and data from data line RBC is fed into multiplexer 102 at input point 118.
The selection between the right block signals and the left block signals are made utilizing transistors MA, MB, MC, and MD. These transistors are p-channel MOSFETs. A low select signal into input point 120, connected to the gates of transistors MA and MB, turns on transistors MA and MB causing the selection of signals from data lines LBT and LBC to be selected and sent out at output points 122 and 124, as true complement signals in data lines MUXT and MUXC respectively. A low select signal into input point 126, which is connected to the gates of transistors MC and MD, causes the true signal in data line RBT to be sent to sense amplifier 104 via output 122 connected to line MUXT and the complement signal from data line RBC to be sent to sense amplifier 104 via output point 124 connected to line MUXC. The use of multiplexer 102 typically causes a signal drop. It is desirable to have as much signal as possible for speed and reliability.
More information on semiconductor memories and sense amplifiers may be found in the following references: Prince, Semiconductor Memories, John Wiley and Sons (2nd Ed. 1991) and Haznedar, Digital Microelectronics, The Benjamin/Cummings Publishing Company, Inc. (1991).
Therefore, it would be desirable to have a method and apparatus for multiplexing and sensing a data signal from a memory array without diminishing the data signal being sensed.
SUMMARY OF THE INVENTION
The present invention provides a memory system, including a memory array having at least two pairs of data lines, first and second data lines corresponding to columns in the memory array. The memory array also includes two level shifter circuits, a first shifter circuit connected to the first lines and a second level shifter circuit connected to the second data lines, wherein the level shifter circuits produce output signals and may be enabled and disabled. A selection signal is used to selectively enable and disable the level shifter circuits, wherein one pair of data lines may be selected. An amplification circuit is connected to the level shifters for amplifying the output signals from the level shifter circuits, and a logic circuit is used to generate logic output signals in response to the amplified output signals from the amplification circuit.
The present invention also includes a multiplexing sense amplifier circuit for use with a memory array, which includes a level shifter stage having two level shifter circuits, a first level shifter circuit connected to a first input line and a first complement input line and a second level shifter circuit connected to a second input line and a second complement input line. Each level shifter circuit has two outputs, a true output and a complement output, and a select input. The level shifter circuits are responsive to a select signal, for enabling or disabling the level shifter circuit. The first level shifter circuit is disabled when the second level shifter circuit is enabled, and the first level shifter circuit is enabled when the second level shifter circuit is disabled, providing selection of signals from one of the two level shifter circuits.
The multiplexing sense amplifier circuit also has a second stage having a true output and a complement output, the second stage being connected to the true and complement outputs of the level shifter stage, wherein the true output and the complement output of the second stage is controlled by the outputs of the level shifter. An amplifier stage or logic circuit may be connected to the true output and the complement output of the second stage. The amplifier has a pair of outputs, wherein the amplifier generates logic 1 and logic 0 signals at the pair of outputs in the amplifier stage in response to signals from the true output and complement output of the second stage. Alternatively, the output of the second stage may be used without the amplifier or logic circuit.
The second stage of the multiplexing sense amplifier may include a pair of current mirrors. Other circuits that may be used in the second stage of the multiplexing sense amplifier include, for example, a p-channel cross-coupled amplifier, a differential amplifier, or a level shifter.
BRIEF DESCRIPTION OF THE DRAWINGS
The novel features believed characteristic of the invention are set forth in the appended claims. The invention itself however, as well as a preferred mode of use, and further objects and advantages thereof, will best be understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying drawings, wherein:
FIG. 1 is a block diagram of a portion of a memory system illustrating a configuration of a memory array, a multiplexer, and a sense amplifier known in the prior art;
FIG. 2 is a block diagram of a sense amplifier known in the prior art;
FIG. 3 is a schematic diagram of a multiplexer known in the prior art;
FIG. 4 is a block diagram of a portion of a memory system configured according to the present invention;
FIG. 5 is a schematic diagram of a cross-coupled level shifter according to the present invention;
FIG. 6 is a schematic diagram of a pair of current mirrors and a p-channel cross-coupled amplifier according the present invention;
FIG. 7 is a schematic diagram of a p-channel cross-coupled amplifier according to the present invention;
FIG. 8 is a schematic diagram of a differential amplifier according to the present invention; and
FIG. 9 is a schematic diagram of a level shift according to the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In accordance with a preferred embodiment of the present invention, the multiplexing function is incorporated into the sense amplifier in order to reduce the effects of having a separate multiplexer selecting signals as illustrated in the prior art design in FIG. 1.
Referring now to FIG. 4, a block diagram of a portion of a memory system configured according to the present invention is illustrated. Memory array 100 again includes left block 100a and right block 100b. Signals from data lines LBT, LBC, RBC, and RBT are fed directly into sense amplifier 130 instead of a multiplexer. Signals from data lines LBT and RBT are true signals, while signals from data lines LBC and RBC are complement signals. In accordance with a preferred embodiment of the present invention, sense amplifier 130 includes level shifter 132, level shifter 134, current mirror stage 136, and amplifier stage 138. Multiplexing functions are incorporated into level shifters 132 and 134 in accordance with a preferred embodiment of the present invention.
Referring now to FIG. 5, a schematic diagram of a cross-coupled level shifter according to the present invention is depicted. Transistors M1-MS comprise the cross-coupled level shifter. These transistors are n-channel and p-channel MOSFETs. Transistors M1, M2, M4-M8 are n-channel MOSFETs, and transistor M3 is a p-channel MOSFET in accordance with the preferred embodiment of the present invention. Input points 150 and 152 receive either signals from data lines LBT and LBC, or signals from data lines RBT and RBC, respectively. These signals control the gates of transistors M1 and M2 respectively. Transistors M7 and M8 are shown in a cross-coupled connection. Other configurations may be used, such as, tying the drain of each transistor, M7 and M8, to the transistor's own gate or by tying the gates to a bias voltage. The drain of transistor M3 is connected to power supply VCC, and the sources of transistors M5-M8 are connected to power supply VSS. These connections provide power to operate the circuit. Power supply VCC is at a higher voltage relative to power supply VSS.
The level shifter incorporates a multiplexing function in accordance with a preferred embodiment of the present invention. This multiplexing function is controlled by a select signal at input point 154 in level shifters 132 and 134. The select signal controls the gate of transistor M3. If the gate of transistor M3 is turned on, the level shifter allows the passage of the true and complement signals through output points 156 and 158 respectively. A high signal at input point 154 disables the level shifter, forcing the output at output points 156 and 158 to be low. On the other hand, when the signal at input point 154 is low, the level shifter performs normally in accordance with a preferred embodiment of the present invention.
By selecting only one of the two level shifters, 132 or 134, as depicted in FIG. 4, a 2 to 1 multiplexing of the signals from the memory array is achieved without diminishing signal strength in accordance with a preferred embodiment of the present invention. The output from output point 156 is a signal LSLT in level shifter 132 and a signal LSRT, right block true signal, in level shifter 134; the output from output point 158 is a signal LSLC, left block complement signal, in level shifter 132 and a signal LSRC, right block complement signal, in level shifter 134. In accordance with a preferred embodiment of the present invention, more than two level shifters may be used depending on the design of the memory system.
Next, FIG. 6 illustrates a schematic diagram of a pair of current mirrors and a p-channel cross-coupled amplifier within a sense amplifier in accordance with a preferred embodiment of the present invention. Current mirror stage 136 includes current mirrors 200 and 202. Current mirror 200 is constructed from transistors M9-M4; current mirror 202 is constructed from transistors M19-M24. Transistors M9, M10, M22, and M23 are p-channel MOSFETs while the rest of the transistors in the two current mirrors are n-channel MOSFETs in accordance with the preferred embodiment of the present invention. P-channel cross-coupled amplifier 204 is constructed from transistors M25-M32. Transistors M25, M26, M30, M31, and M32, are p-channel transistors, while transistors M27, M28, and M29 are n-channel transistors in p-channel cross-coupled amplifier 204. Transistors M25-M28 form a flipflop in this circuit. Transistor M32 is employed to provide balancing within the circuit, and transistors M30 and M31 are utilized to pre-charge the circuit.
Transistors M15-M18 are employed to enable, disable, and pre-charge the sense amplifier in accordance with a preferred embodiment of the present invention. The current mirrors and the amplifier are powered by connecting the drains of transistors M9, M10, M15, M18, M22, M23, M25, M26, M30, and M31 to power supply VCC, while the sources of transistors M16, and M29 are connected to power supply VSS. Power supply VCC is typically at a higher voltage than power supply VSS.
Signals at input points 206, 207, and 208 enable and disable the circuits. Input points 210 and 212 carry signals LSRC and LSRT from level shifter 134 while input points 214 and 218 carry signal LSLC from level shifter 132. Input points 216 and 220 carry signal LSRT from level shifter 132. Signal LSRC controls the gates of transistors M11 and M20; signal LSRT controls the gates of transistors M12 and M21. Transistors M13 and M24 are controlled by signal LSLT; transistors M14 and M19 are controlled by signal LSLC.
In accordance with a preferred embodiment of the present invention, current mirrors 200 and 202 are current mirrors with additional transistors added in parallel to control the output of the current mirrors. Transistors M12 and M13 are connected in parallel; transistors M11 and M14 are in parallel; transistors M21 and M24 are connected in parallel; and transistors M20 and M19 are connected in parallel. These transistors control the current flow in the current mirrors.
If level shifter 134 is not selected and level shifter 132 has been selected, the signals at input points 210 and 212 are low. A low signal is a signal that turns the transistor off. As a result, transistors M11, M12, M20, and M21 are turned off. The signals at input points 214, 216, 218 and 220 correspond to the output from level shifter 132, resulting in various levels of current flowing through transistors M13, M14, M24, and M19 depending on the voltage at the gates of transistors by signals supplied by lines LSLT and LSLC. The output signals, OUTT and OUTC, from these two current mirrors control the gates of transistors M27 and M28 in p-channel cross-coupled amplifier 204 resulting in output signals DATAT and DATAC at output points 222 and 224 respectively. Signal DATAC is the complement of signal DATAT.
Current mirror stage 136 in FIG. 4 may be replaced by a number of different stages in accordance with a preferred embodiment of the present invention. For example, a p-channel cross-coupled amplifier 298, as depicted in FIG. 7, may be utilized in place of the two current mirrors 200 and 202 illustrated in FIG. 6. P-channel cross-coupled amplifier 298 is constructed from transistors T1-T11. Transistors T1, T2, T8, T10, and T11 are p-channel MOSFETs. The remaining transistors are n-channel MOSFETs. P-channel cross-coupled amplifier 298 is powered by connecting transistors T1, T2, T10, and T11 to power supply VCC and connecting the drain of transistor T7 to power supply VSS.
P-channel cross-coupled amplifier 298 is enabled when a select signal is high at input points 300, 301, 302, and 303. These signals control the gates of transistors T1, T2, T7, and T8. Input points 304 and 306 are connected to the gates of transistors T3 and T4 respectively; input points 308 and 310 are connected to the gates of transistors T5 and T6 respectively. Again, a parallel configuration of transistor T3 in parallel with transistor T4 and transistor T5 in parallel with transistor T6 is employed in accordance with a preferred embodiment of the present invention. Signal LSLT enters input point 304; signal LSRT enters input point 306; signal LSRC enters input point 308; and signal LSLC enters input point 310. If level shifter 134 is disabled and level shifter 132 is selected, signals LSRT and LSRC will be low, causing transistors T4 and T5 to be turned off. Signals LSLT and LSLC will correspond to the output from level shifter 132, allowing various amounts of current to flow through transistors T3 and T6 in response to different voltages being applied to the gates of these two transistors in accordance with a preferred embodiment of the present invention.
Transistors T10 and T11 are the cross-coupled p-channel MOSFETs within the amplifier. Signal OUTC travels from output point 312 to transistor M28 in amplifier 204 in FIG. 6. Signal OUTT travels from output point 314 to transistor M27 in amplifier 204 in FIG. 6. The depicted embodiment in FIG. 6 illustrates employing an amplifier connected to the current mirrors to produce a logic signal. According to the present invention, some other logic circuit may be used in place of amplifier 204. Furthermore, the circuit below current mirrors 200 and 202 may be eliminated, and the output from current mirrors 200 and 202 may be directly used as the output of the sense amplifier.
Referring now to FIG. 8, a schematic diagram of a differential amplifier, which may be substituted in place of current mirrors 200 and 202 in FIG. 6, is illustrated in accordance with a preferred embodiment of the present invention. Differential amplifier 350 is comprised of transistors T20-T29. Transistors T20-T23 and T26 are p-channel MOSFETs while the remaining transistors are n-channel MOSFETs. This circuit is powered by connecting the drains of transistors T20, T21, T22, and T23 to power supply VCC and connecting the source of transistor T29 to power supply VSS.
Transistors T20, T23, T26 and T29 enable and disable differential amplifier 350. These transistors are controlled by control signals at input points 352, 354, 356, and 358. A bias signal (or ground) is applied to the amplifier at input point 360, which controls the gates of transistors T21 and T22. Transistor T28 is controlled by signal LSLT at input point 362. Transistor T27 is controlled by signal LSRT at input point 364. Transistor T25 is controlled by signal LSRC at input point 366. Transistor T24 is controlled by signal LSLC at input point 368. Output point 353 is connected to the gate of transistor M28 in amplifier 204 and provides a complement output signal OUTC, while output point 355 is connected to the gate of transistor M27 in amplifier 204 and provides an output signal, OUTT.
Referring now to FIG. 9, transistors T40-T50 are utilized to form a level shifter that may be utilized in place of current mirrors 200 and 202 in FIG. 6. Transistors T40, T46, and T50 are p-channel MOSFETs, while transistors T41, T42, T43, T44, T47, T48, and T49 are n-channel MOSFETs in accordance with a preferred embodiment of the present invention. Transistors T40, T46, T49, and T50 are employed to enable and disable the circuit. Control signals at input points 400, 402, 404, and 406 control the gates of these transistors. The circuit is powered by connecting the drains of transistors T40, T41, T44, and T46 to power supply VCC, while connecting the source of transistor T49 to power supply VSS.
Transistor T41 is controlled by signal LSLT applied to input point 408. Transistor T42 is controlled by signal LSRT applied to input point 410; transistor T43 is controlled by signal LSRC applied to input point 412; and transistor T44 is controlled by signal LSLC applied to input point 414. Transistors T41 and T42 are in parallel; transistors T43 and T44 are in parallel. Output point 416 is connected to the gate of transistor M27 in amplifier 204 in FIG. 6. Output point 418 is connected to the gate of transistor M28 in amplifier 204 is FIG. 6. The output signals at output points 416 and 418 are determined by the input signals at input points 408, 410, 412, and 414. For example, if level shifter 134 is disabled and level shifter 132 is selected, transistors T41 and T44 would be turned on, while transistors T42 and T43 would be turned off. The output at output point 416 would depend on signal LSLT at input point 408, which controls transistor T41. The output at output point 418 would depend on signal LSLC at input point 414, controlling transistor T44.
The present invention allows for selection of signals by enabling and disabling a pair of level shifters, instead of using a separate multiplexer. Transistors controlling the output in later stages are placed in parallel and controlled by the output signals from the level shifters. Although, two level shifters are depicted, other numbers of level shifters may be utilized in different memory array configurations. Although the depicted embodiment illustrates the selection of signals by enabling and disabling a pair of level shifters, other circuits other than level shifters may be manipulated in a similar function within a sense amplifier to provide selection of signals.
In addition, the depicted embodiment illustrates an implementation involving pairs of data lines, carrying true and complement signals. Those of ordinary skill in the art will appreciate that a single data line implementation, instead of a pair of data lines, may be employed according to the present invention. A differential amplifier may be used to produce a true and complement signal from a single data line.
One advantage of the present invention is that it provides a faster and more sensitive sense amplifier because signal losses resulting from signals propagating through a transmission gate in a multiplexer stage are eliminated. Additionally, the present invention provides for smaller and simpler circuitry for selecting and sensing signals from data lines in multiple blocks of memory. The present invention is depicted using MOS technology. Other types of technology and transistors may be utilized in accordance with a preferred embodiment of the present invention.
While the invention has been particularly shown and described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention.
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A memory system comprising a memory array having at least two pairs of data lines, first and second data lines corresponding to columns in the memory array. The memory array also includes two level shifter circuits, a first shifter circuit connected to the first lines and a second level shifter circuit connected to the second data lines, wherein the level shifter circuits produce output signals and may be enabled and disabled. A selection signal is used to selectively enable and disable the level shifter circuits, wherein one pair of data lines may be selected. An amplification circuit is connected to the level shifters for amplifying the output signals from the level shifter circuits, and a logic circuit is used to generate logic output signals in response to the amplified output signals from the amplification circuit.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of German Patent Application No. DE 10 2007 044 577.8, filed Sep. 19, 2007, in the German Patent Office.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a door-closing device for a domestic electrical appliance. Particularly, the present invention relates to a door-closing device comprising a frame with an aperture for the introduction of a keeper or the like, a closing unit which is arranged on the frame so as to be movable, relative to the latter, and which, in a closing position, holds the keeper fast for the purpose of keeping the door closed and, in an open position, releases the keeper for the purpose of opening the door, the closing unit, in the course of its transfer from the open position into the closing position, drawing the keeper along with it along part of the keeper's path of movement, relative to the frame, a closing spring arrangement which acts upon the closing unit and which supplies the force necessary for drawing the keeper along with the unit, and a blocking system by which the closing unit can be blocked from moving out of the open position and into the closing position, it being possible to set aside the blocking of the closing unit by relative movement of said blocking system and closing unit.
2. Description of the Prior Art
A door-closing device of this kind with a pulling-shut function, that is to say spring-assisted pulling-shut of the door, is known, for example, from US 2005/0194795 A1. In this known solution, a blocking pin is provided which is arranged so as to be integral with the frame. The closing unit comprises a linearly movable carriage on which a rotary member is held so as to be movable about an axis of rotation. An arrangement of a number of helical compression springs is inserted between the carriage and a framework belonging to the door-closing device. The force of the helical compression springs pretensions the rotary member towards the blocking pin. The rotary member possesses a slot which is open in the radially outward direction and into which, when the closing unit is in the open position, the keeper moves on closure of the door. In the process, the keeper strikes against one of the flanks of the slot. This action of the keeper upon the rotary member leads to rotation of the latter about the axis of rotation, the outer peripheral face of said rotary member sliding along the blocking pin. Under these circumstances, considerable frictional forces can operate between the blocking pin and the rotary member, depending upon the firmness of the helical compression springs. While the keeper which has been introduced is rotating the rotary member, that part of said rotary member which adjoins the other flank of the slot engages in a clearance in the keeper. As soon as an edge at which the outer peripheral face of the rotary member bends away in the radially inward direction slips past the blocking pin, the helical compression springs are able to expand and thrust the carriage away. In the course of this displacement of the carriage, the keeper is drawn along with the rotary member by the latter, which now presses, with the other flank of its slot, against said keeper.
Another door fastener with a pulling-shut function, which door fastener is not a generic one however, is known from EP 1 344 486 A2. In this door fastener, a rotary member, to which a helical compression spring which supplies the pulling-shut force is attached by one of its ends, serves as the closing unit. When the fastener is in an open state, the straight line of force extending between the points at which the helical compression spring is attached lies on one side of the axis of rotation of the rotary member and pretensions the latter in the direction of an open position. When the fastener is closed, the straight line of force of the helical compression spring moves away over the axis of rotation of the rotary member and comes to rest on the other side of said axis of rotation. The pretensioning action of the helical compression spring is then in the direction of the closing position of the rotary member. In order to close the door, it is therefore first necessary to operate against the force of the helical compression spring. This comes about through the fact that a keeper which has been introduced strikes against one of the flanks of a slot constructed in the rotary member and thereby moves the latter away over the dead centre at which the straight line of force of the helical compression spring passes precisely through the axis of rotation. As soon as the dead centre has been crossed, the spring expands and drives the rotary member into its closing position. In the process, the keeper which is now trapped in the slot in the rotary member is drawn along with it. What is problematic about the fastener according to EP 1 344 486 A2 is that, for a low initial force of resistance when the door is being closed, the straight line of force of the helical compression spring is supposed to be removed only a little way from the dead-centre position, but this at the same time entails an increased susceptibility to unwanted automatic closing of the catch if vibration or jolting occurs.
German Laying-Open Specification DE 10 2006 037 494 A1, which was published subsequently, indicates a door-closing device with a pulling-shut function in which, on closure of the door, a closing body with a projecting nose plunges into a closing trough formed on the door and then snaps back under the action of an expanding closing spring, as a result of which the door is pulled shut. Said door first of all strikes against a control lever which is separated from the closing body and which is set in motion as a result. The rotating control lever in turn presses the closing body down against a blocking face formed by a base frame of the closing device. As soon as the closing body passes the blocking face, the closing spring is able to expand.
German Laying-Open Specification DE 10 2007 025 295 A1, which was likewise published subsequently, indicates a door fastener having a closing member which is guided, via two spindles, so as to be movable within a guide groove in a fastener housing and which, on closure of the door, grasps a closing catch arranged on the door and then moves, under the action of an expanding closing spring, in such a way that the door catch is pulled into the fastener. The course of the guide groove exhibits an inflexion which has to be overcome by one of the spindles of the closing member so that the closing spring is able to expand for the purpose of deploying its pulling-shut action.
SUMMARY OF THE INVENTION
The object of the invention is to provide a door-closing device of the type initially referred to, which can be closed with high functional reliability and little expenditure of force and which, in addition, can preferably provide high holding power when in the closed state.
In order to achieve this object, a door-closing device of generic type is characterised, according to the invention, in that the blocking system is formed by a blocking element which is arranged so as to be movable, relative to the frame, between a blocking position and a releasing position and which, in the blocking position, prevents a movement of the closing unit out of the open position and into the closing position and, in the releasing position, permits such a movement of the closing unit, and that the blocking element is constructed and arranged in such a way that it can be lifted by the keeper out of its blocking position and into its releasing position, against the action of a restoring force, on closure of the door.
The door-closing device according to the invention can be used, for example, in washing machines, dishwashers or tumble driers. When it is introduced into the aperture in the frame, the keeper, which is constructed, for example, with a leading transverse stud, lateral cheeks adjoining the latter and a gripping recess, which lies behind said transverse stud and between the lateral cheeks, for a gripping section of the closing unit, impinges upon the blocking element and lifts the latter out of its blocking position and into the releasing position. As a result of this, the closing unit becomes free and is able to move into the closing position under the action of the closing spring arrangement. It is thus possible, with simple means, to guarantee high stability of the blocking arrangement which is not susceptible to shaking or vibrating influences. At the same time, a design which permits unblocking of the closing unit with comparatively little expenditure of force is also possible.
According to one further development of the invention, the closing unit may, when the door-closing device is in a state preparatory to closing, prior to the introduction of the keeper into the aperture in the frame, be in blocking abutting contact with the blocking element, said closing unit being constructed and arranged in such a way that, on closure of the door, said unit is initially lifted by the keeper out of blocking abutting contact with said blocking element in the direction away from the closing position, before said keeper forces the blocking element into its releasing position. In this configuration, the blocking element is first of all relieved of load through the fact that the keeper which has been introduced drives the closing unit out of the open position and slightly in the direction away from the closing position, and therefore out of abutment against the blocking element. In its open position, the closing unit accordingly possesses a certain degree of mobility in the direction away from its closing position. In this context, “open position” means that position of the closing unit which it normally assumes when the door is open. The relieving of the load on the blocking element as a result of deflection of the closing unit by the incoming keeper then facilitates the lifting-out of the blocking element and thus the closing operation as a whole.
The provision of a blocking element which can be moved separately and the actuation of said element by the keeper also permit reliable identification of the state of the door (i.e. open or closed). An electrical switch, which interacts with the blocking element and the switching state of which depends upon the position of said element, may be provided for this purpose. Under these circumstances, the closing unit and blocking element are advantageously constructed and arranged in such a way that, when the closing unit is in the closing position with the keeper absent, the blocking element at least approximately assumes its blocking position.
If, in this configuration, the blocking element is lifted, when the door is open, out of its blocking position either inadvertently or intentionally, for instance by a playing child who penetrates the frame with an object through the aperture in said frame, the closing unit which has now been released admittedly turns over into its closing position. However the blocking element is able, when the playing child lets go of it again, to return to its blocking position in which the electrical switch assumes the same switching state as when the door-closing device is in the normal, open state. Although, therefore, the closing unit has passed over into its closing position, the electrical switch nevertheless continues—correctly—to indicate an open door. Only when the door has actually been closed and the keeper has been introduced into the aperture in the frame is the blocking element held in its releasing position by the keeper. The switch then correctly indicates the closed state of the door.
The blocking element is preferably formed by a blocking lever which is mounted so as to be pivotable, relative to the frame. Alternatively, said blocking element may be formed, for example, by a blocking slide which is guided so as to be movable in a linear manner, relative to said frame. In these cases, a separate pretensioning element which generates the restoring force is expediently associated with the blocking element.
The blocking element may also alternatively be formed, according to one variation, by a flexible blocking body. In this case, it is possible to dispense with an additional pretensioning element for generating the restoring force; the restoring force may be generated by the blocking body itself in the course of its elastic deflection. Said blocking body may, for example, be produced from spring steel sheet.
The closing unit may be formed by a rotary member which is rotatable about an axis of rotation which is stationary, relative to the frame, and the axis of rotation of which member extends at a radial distance from the path of movement of the keeper, relative to the frame. Under these circumstances, the rotary member preferably has a radially protruding gripping section which grasps the keeper, on closure of the door, and draws said keeper along with itself while rotating the rotary member, the movement of the gripping section after the grasping of the keeper possessing a substantial, in particular predominant, component in the direction of the path of movement of the keeper. In this way, a major tractive force can be exerted on said keeper by the rotary member.
The closing spring arrangement may comprise at least one spiral spring which acts upon the rotary member and is loaded in tension or compression and the straight line of force of which, observed in a section normal to the axis, always lies on the same side of the axis of rotation, but is at a smaller radial distance from said axis of rotation in the open position than in the closing position. This is advantageous in so far as the radial distance of the straight line of force from the axis of rotation, which distance is becoming increasingly greater, permits great closing force when the door is being closed. This is favourable for leakproof and secure closing of the door.
As an alternative to a spiral spring which is loaded in tension or compression, the closing spring arrangement may comprise, for example, at least one torsion spring that acts upon the rotary member.
Irrespective of its actual mobility (whether rotatable or of another kind) in relation to the frame, the closing unit is preferably formed by a single closing body, the said closing body having a gripping section which grasps the keeper, on closure of the door, and draws said keeper along with itself while moving the closing body. Under these circumstances, the movement of the gripping section after the grasping of the keeper possesses an at least predominant component in the direction of the path of movement of said keeper, a fact which—as has already been alluded to above—is favourable for a high tractive force upon the keeper.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be explained in greater detail below with the aid of the appended drawings, in which:
FIGS. 1 and 2 represent perspective views of a door-closing device according to a first exemplified embodiment;
FIG. 3 represents a sectional view of the door-closing device in FIGS. 1 and 2 , in a state preparatory to closing;
FIG. 4 represents a sectional view of the door-closing device in FIGS. 1 and 2 , during a closing operation;
FIG. 5 represents a sectional view of the door-closing device in FIGS. 1 and 2 , after the door has been closed;
FIG. 6 represents a sectional view of the door-closing device in FIGS. 1 and 2 , in a closing state without the keeper introduced;
FIGS. 7 and 8 represent partially cut-away perspective views of the door-closing device in FIGS. 1 and 2 for the purpose of illustrating the dependence of the switching state of an electrical switch upon the position of a blocking element belonging to the door-closing device;
FIGS. 9 and 10 represent perspective views of a door-closing device according to a second exemplified embodiment;
FIG. 11 represents a sectional view of the door-closing device in figures 9 and 10 , in a state preparatory to closing;
FIG. 12 represents a sectional view of the door-closing device in figures 9 and 10 , during a closing operation; and
FIG. 13 represents a sectional view of the door-closing device in FIGS. 9 and 10 , with the door closed.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
For the purpose of explaining the first exemplified embodiment, reference will initially be made, in particular, to FIGS. 1 to 3 . A door-closing device, which is designated generally by 10 , is shown therein in a state preparatory to closing, in which it is being prepared for closing the door of a domestic electrical appliance, for instance a washing machine or a dishwasher. The door-closing device 10 comprises a framework 12 on which various other components of said device are mounted and which, according to one variant, is intended and constructed for installation in the main housing of the domestic appliance. Said framework 12 possesses an aperture 14 into which a keeper (door catch) 16 , which in this variant is located on the door, moves on closure of the door of the domestic appliance. The keeper 16 possesses a point 18 behind which a gripping clearance 20 is located. In the sectional representation in FIG. 3 , it can be seen that the point 18 of the keeper possesses lateral flanks that run towards one another obliquely.
In another variant, the framework 12 is mounted, by means of its installing components, on the door of the domestic appliance, while the keeper 16 is fitted to the main housing of said appliance. The door serves to occlude an aperture through which a working space provided in the main housing of the appliance is accessible for the purpose of receiving dishes, washing or the like. In many cases, a so-called “door seal”, which is compressed to a greater or lesser extent when the door is closed, will extend around the access aperture. This door seal may be fitted to the door or to the main housing of the appliance. For the purpose of compressing the door seal, a force is necessary which is applied, at least partially, by the door-closing device 10 itself, namely by spring means which will be described in greater detail later on and which expand on closure of the door and, in the process, pull said door towards the main housing of the appliance.
A rotary member 22 which serves as the closing unit is held on the framework 12 so at to be rotationally movable about an axis of rotation 24 which is integral with the frame. In the state preparatory to closing according to FIG. 3 , the rotary member 22 is in a so-called “open position”, from which it can be rotated in the clockwise direction into a closing position which is shown in FIG. 5 . In addition to this, the rotary member 22 can be deflected out of the open position in FIG. 3 in the anticlockwise direction by a small amount and into the rotational position shown in FIG. 4 . In each rotational position, the rotary member 22 is pretensioned by a closing spring 26 in the direction of the closing position according to FIG. 5 . In the exemplified embodiment in FIGS. 1 to 8 , said closing spring 26 is formed by a spiral spring which acts as a leg spring, i.e. is loaded in rotation, and the axis of which substantially coincides with the axis of rotation 24 of the rotary member 22 .
Rotary member 22 possesses a radially protruding gripping or entraining section 28 which, in the open position according to FIG. 3 , projects slightly into the path of movement of the keeper 16 , namely in such a way that said keeper 16 , when it moves into the frame aperture 14 (i.e. on closure of the door), impinges upon the gripping section 28 with the lower oblique flank of its point 18 . This brings about the aforementioned slight deflection of the rotary member 22 into the rotational position according to FIG. 4 .
The path of movement of the keeper 16 , relative to the frame 12 and therefore relative to the rotary member 22 which is held in said frame 12 , is indicated by an arrow 29 in FIG. 3 . Although the door will normally be fitted to the main housing of the appliance in a pivotingly movable manner, the relative path of movement of the keeper 16 can be regarded as being approximately rectilinear on a small scale, i.e. over short distances, even if, on the whole, it follows a circular path. That is why the arrow 29 is drawn in as a straight arrow in FIG. 3 .
The path of movement of the keeper 16 , relative to the frame 12 , extends at a radial distance from the axis of rotation 24 of the rotary member 22 . This becomes clear if the arrow 29 in FIG. 3 is imagined as being prolonged; it then runs past said axis of rotation 24 at a radial distance above the latter.
In the open position according to FIG. 3 , the rotary member 22 is prevented by a blocking lever 30 from rotating into the closing position according to FIG. 5 . Said blocking lever 30 is held on the framework 12 so as to be pivotingly movable about an axis of pivoting 32 extending parallel to the axis of rotation 24 . It possesses a blocking shoulder 34 with which a radially projecting nose 36 on the rotary member 22 interacts. Said blocking lever 30 possesses axially, on either side of the blocking shoulder 34 , extensions 38 with which the keeper 16 interacts on closure of the door. The nose 36 on the rotary member 22 moves freely between said extensions 38 on the blocking lever 30 .
The blocking lever 30 is pivotingly movable between a blocking position which is shown in FIG. 3 and a releasing position which is shown in FIG. 5 . A pretensioning element 40 which is constructed, in this case, as a leg spring pretensions the blocking lever 30 in the direction of its blocking position according to FIG. 3 . The end faces of its extensions 38 form contact surfaces for the keeper 16 which, on moving into the aperture 14 in the frame, strikes against the said end faces with its point 18 , as is shown in FIG. 4 . If the keeper 16 is then advanced further, it presses the blocking lever 30 upwards out of the blocking position and in the direction of the releasing position against the force of the pretensioning spring 40 . This state is shown in FIG. 5 .
In the releasing position, the blocking shoulder 34 is moved radially out of the range of the nose 36 on the rotary member 22 , so that the latter is able to rotate unhindered into its closing position. However said rotary member 22 moves into its closing position only when the keeper 16 has moved into the aperture 14 in the frame sufficiently far for the gripping section 28 of the rotary member 22 to be able to plunge into the gripping clearance 20 in the keeper 16 . As soon as the gripping section 28 engages in the gripping clearance 20 , the rotary member 22 , in the course of its rotation into the closing position, pulls the keeper 16 deeper into the aperture 14 in the frame. The force needed for this pulling-shut movement is applied by the closing spring 26 , which expands as the rotary member 22 moves from the open position into the closing position.
When the rotary member 22 rotates, the gripping section 28 follows a circular path. During the phase in which the gripping section 28 is in entraining engagement with the keeper 16 , said gripping section 28 moves along one such part of the said circular path, on which part it has a substantial, in particular predominant, component in the direction of the path of movement of the keeper 16 , that is to say in the direction of the arrow 29 . As a result of this, the rotary member 22 is able to exert a comparatively high entraining force upon the keeper 16 in the direction of the arrow 29 . This force may, at the same time, bring about, or at least assist in, the compression of a door seal which may optionally be present on the domestic appliance.
In the closing state according to FIG. 5 , the blocking lever 30 continues to be held in its releasing position by the keeper 16 . Under these circumstances, the extensions 38 on the blocking lever 30 are supported, in a manner of which no further details are represented, against side walls which laterally delimit the gripping clearance 20 in the keeper 16 .
On closure of the door, there first of all takes place the deflection of the rotary member 22 into the position according to FIG. 4 , as a result of which the abutting contact between the nose 36 and the blocking shoulder 34 is set aside. This relieves the load on the blocking lever 30 , a fact which facilitates the subsequent lifting-out of the latter by the keeper 16 . It should be pointed out, of course, that it is possible, according to one variation, to dispense with prior deflection of the rotary member 22 for the purpose of terminating the abutting contact with the blocking lever 30 . In this variation, the keeper 16 moves past the gripping section 28 on being introduced into the aperture 14 in the frame, without coming into deflecting contact with said gripping section and pressing it downwards. The lifting-out of the blocking lever 30 by means of the keeper 16 which is moving in then takes place, without any change, in the manner which has been described so far, although of course the abutting contact that continues to exist between the nose 36 and the blocking shoulder 34 leads, under certain circumstances, to increased, friction-induced resistance.
Situations can be conceived of in which the rotary member 22 passes into its closing position without closing the door in the process. This can happen, for example, if a child is playing with the door-closing device and sticks an object into the aperture 14 in the frame. If the child strikes against the blocking lever 30 sufficiently hard, the possibility of the rotary member 22 being released and rotating into its closing position cannot be ruled out. In such an event, the blocking lever 30 can return, after the playing child has let go of it again, to its blocking position without colliding with the rotary member 22 . As can be clearly seen in FIG. 6 , after the return of the blocking lever 30 into the blocking position, the gripping section 28 of the rotary member 22 is located in the clear space formed between the extensions 38 on said blocking lever 30 . Reciprocal obstruction of the rotary member 22 and blocking lever 30 does not take place in this state.
The ability of the blocking lever 30 to still return substantially into its blocking position after irregular actuation of the rotary member 22 (in this case, “irregular” means: without the introduction of the keeper 16 ) can advantageously be utilised in conjunction with an electrical switch that indicates the closing state of the door-closing device. A switch of this kind is shown at 42 in FIG. 2 . In addition, it can be seen, in FIGS. 7 and 8 , that the blocking lever 30 possesses an actuating section 44 which is constructed here as an arm which projects away laterally and which serves to actuate a mechanical sensor 46 belonging to the electrical switch 42 . In the state according to FIG. 7 , the blocking lever 30 assumes its blocking position. In this state, the actuating section 44 presses the sensor 46 down, a fact which corresponds to a first switching state of the electrical switch 42 . In FIG. 8 , on the other hand, the blocking lever 30 is located in its releasing position in which it is held by the keeper 16 which has been introduced. In this state, the actuating section 44 no longer presses on the sensor 46 , a fact which corresponds to a second switching state of the electrical switch 42 . The switching state of said electrical switch 42 accordingly gives reliable information as to whether the door is closed or open. For only when the door is actually closed does the blocking lever 30 remain in its releasing position; without the keeper 16 introduced, it returns at least approximately to its blocking position, at any rate after the door-closing device has been left alone again.
As an alternative to an inherently rigid blocking element, the blocking element may conceivably be manufactured from a flexible material, say from a piece of spring steel sheet. In such a case, it is possible to dispense with a separate pretensioning spring for said blocking element.
For the purpose of explaining the second exemplified embodiment, reference will now be made to FIGS. 9 to 13 . In said second exemplified embodiment, components which are identical or which have an identical action are provided with the same reference symbols as before, but with the addition of a lower-case letter. In order to avoid unnecessary repetitions, the reader is referred to the above description of the first exemplified embodiment, provided that nothing to the contrary arises below.
The exemplified embodiment in FIGS. 9 to 13 differs from the first exemplified embodiment substantially as a result of a different way of generating the spring pretensioning for the rotary member 22 a. In concrete terms, two helical draw springs 26 a serve to generate the said pretensioning. The rotary member 22 a, which is of disc-like design, is designed, on each of its axial sides, with an axially protruding peg 48 a which is arranged eccentrically to the axis of rotation 24 a and to which one of the helical draw springs 26 a is attached, in each case, by one of its ends. At their other ends, the two helical draw springs 26 a are attached to the framework 12 a in each case, as is indicated at 50 a in FIGS. 11 to 13 . The drawing action of each of the helical draw springs 26 a extends along a straight line which connects the two points of attachment of the helical draw spring 26 a in question to the framework 12 a and to the rotary member 22 a. In FIGS. 11 and 13 , a straight line of this kind is indicated at 52 a. It will also be referred to below as the “straight line of force” of the helical draw spring 26 a in question.
The location of the straight line of force 52 a of each helical draw spring 26 a varies with respect to the axis of rotation 24 a on account of the variable rotational position of the rotary member 22 a when the door is opened and closed, and the eccentricity of the attachment pegs 48 a. In concrete terms, the straight line of force 52 a moves within a plane which extends transversely, and in particular normally, to the axis of rotation 24 a, said straight line of force always lying on the same side of the axis of rotation 24 a and always being at a radial distance from the latter. In the state preparatory to closing according to FIG. 11 (which corresponds to the open position of the rotary member 22 a ), this radial distance is comparatively small, whereas in the closing state according to FIG. 13 (which corresponds to the closing position of said rotary member 22 a ), the radial distance between the straight line of force 52 a and the axis of rotation 24 a is substantially greater. Although the helical draw springs 26 a are tensioned more weakly when the door-closing device is in the closing state than when it is in the state preparatory to closing, a comparatively large closing momentum, which guarantees reliable, leakproof closing of the door, is nevertheless operative because of the larger radial distance of the straight line of force 52 a from the axis of rotation 24 a. On the other hand, the operative torque exerted by the helical draw springs 26 a on the rotary member 22 a is comparatively small, when the door-closing device is in the state preparatory to closing, on account of the smaller radial distance of the straight line of force 52 a from the axis of rotation 24 a, although the helical draw springs 26 a are under stronger tension than in the closing state. This is advantageous, among other things, for gentle opening of the door.
In the second exemplified embodiment too, as in the first, the keeper 16 a can initially, on moving into the aperture 14 a in the frame, easily deflect the rotary member 22 a out of its open position and in the direction away from the closing position, in order to thus set aside the abutting contact between the nose 36 a on the rotary member 22 a and the blocking shoulder 34 a on the blocking lever 30 a, before the keeper 16 a presses said blocking lever 30 a up into its releasing position. Even in the case of such prior deflection of the rotary member 22 a, the straight line of force 52 a of each helical draw spring 26 a remains at a certain radial distance from the axis of rotation 24 a, so that pretensioning in the direction of the closing position is operative in any rotational position of said rotary member 22 a. It is obviously possible, of course, even in the case of the second exemplified embodiment, to dispense with the prior slight deflection of the rotary member 22 a if desired.
Although the preferred embodiments of the present invention have been described herein, the above description is merely illustrative. Further modification of the invention herein disclosed will occur to those skilled in the respective arts and all such modifications are deemed to be within the scope of the invention as defined by the appended claims.
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A door-closing device for a domestic electrical appliance comprises a frame with an aperture for the introduction of a keeper. A closing unit is arranged on the frame such that when in a closing position, the closing unit holds the keeper for the purposed of keeping the door closed and, in an open position, releases said keeper for the purposed of opening the door, said closing unit, in the course of its transfer from the open position into the closing position, draws the keeper along with it. A closing spring arrangement acts upon the closing unit to draw the keeper along with said unit. A blocking element that is movable relative to the frame to block and unblock the movement of the closing unit.
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The ability to affect fluids in the downhole environment is both a necessary part of hydrocarbon production and a source of consternation in some applications due to inherent difficulty in creating the desired effect. In some cases, work is performed on the fluid from remote locations while in other cases, work is performed on the fluid locally. Where work is performed locally, there are added difficulties to overcome such as providing power to whatever device is doing the work, etc. In some situations, such difficulties are overcome and the operation goes forward without significant difficulty with a particular set of tools and/or components and/or processes. The same paradigm however may not work well for another wellbore or even for another section of the same wellbore. Therefore, the art is always receptive to new arrangements and methods for doing “work” on a fluid in the downhole environment.
SUMMARY
A downhole arrangement including an outer housing, an inner housing disposed within the outer housing and defining with the outer housing a chamber, a turbine disposed within the chamber, and one or more nozzles disposed at the chamber capable of exhausting steam into the chamber.
A method for moving a target fluid within a wellbore including supplying a reactant fuel to a catalyst nozzle in a downhole arrangement and exhausting a resultant steam through a turbine.
BRIEF DESCRIPTION OF THE DRAWINGS
Referring now to the drawings wherein like elements are numbered alike in the several Figures:
FIG. 1 is a schematic view of a steam turbine driven configuration in accordance with the disclosure hereof.
FIG. 2 is a schematic view of another steam turbine driven configuration in accordance with the disclosure hereof.
DETAILED DESCRIPTION
Referring to FIG. 1 , an arrangement 10 is illustrated that facilitates the application of work to a fluid in the downhole environment. The arrangement 10 includes an outer housing 12 . The housing 12 supports one or more catalyst nozzles 14 that are fluidly connected to a reactant fuel source through one or more conduits 16 , which may comprise commonly used control line.
The catalyst that is provided within the nozzle 14 is a powdered precious metal-based catalyst (available from Oxford Catalysts Group PLC trading under Oxford Catalysts Limited, 115e Milton Park, Oxford, OX14 4RZ, UK). The reactant fuel (e.g. aqueous methanol and hydrogen peroxide) is supplied to the catalyst through the conduit(s) 16 as noted whereby an exothermic reaction takes place. The reaction produces water, carbon dioxide and heat thereby generating steam at a selected temperature up to about 1500° F. and at atmospheric pressure. The pressure with which the steam is applied to an end target can be adjusted by increasing or decreasing the pressure of the reactant fuel mixture supplied to the catalyst.
Nozzles 14 are directed to exhaust steam to a chamber 18 that is defined at an outside surface by housing 12 and at an inside surface by an inner housing 20 . In this embodiment, a downhole end of the chamber 18 is closed by closure member 22 , which ensures that all steam created by fuel passing through the nozzles 14 will act upon a turbine 24 that is rotatably supported between the housing 12 and the housing 20 . Expanding steam through a plurality of vanes of the turbine allows the turbine to extract energy from the steam and put is to useable work. In this iteration of the arrangement 10 the energy is used to drive a pump.
In the illustrated embodiment, a pump impeller 28 (the pump) is drivingly connected to the turbine 24 by a shaft 30 . The impeller 28 thereby spins with the turbine causing a target fluid 32 to move through an inlet 34 of the inner housing toward a directed destination.
While the arrangement 10 will function to move the target fluid 32 toward a desired destination as has been disclosed, the movement of the fluid can be augmented within the operation of the arrangement 10 . More specifically, a review of FIG. 1 , will make clear that the inner housing 20 ends at a downstream end 36 of inner housing 20 that is still within a volume defined by the outer housing 12 . Steam that has passed through the turbine 24 will consequently mix with the target fluid 32 downstream of the end 36 , in zone 38 . Those of skill in the art will recognize such a condition to be a gas lift condition as the steam will reduce the density of the target fluid 32 making it easier for the fluid to move to a surface or other location.
In another embodiment of the arrangement 10 , referring to FIG. 2 , a positive displacement pump 40 is substituted for the action of the impeller 28 and a gear reducer 42 is added between the turbine 24 and the pump 40 in order to ensure that sufficient torque is available to drive the pump 40 . This of course requires that shaft 30 be bifurcated to a primary shaft 30 a and a secondary shaft 30 b . In other respects, the embodiment of FIG. 2 operates as does that of FIG. 1 .
In operation, the arrangement 10 is run into the downhole environment and at least an inlet 34 of the arrangement 10 into contact with a target fluid 32 . Fuel can then be supplied at any time to begin the steam generation process. Once the fuel is brought into contact with the one or more nozzles 14 , the catalyst in the nozzles 14 will react with the fuel to produce steam at a selected temperature and pressure. The steam will naturally be directed through the turbine from the chamber 18 thereby spinning the turbine. The energy extracted by the turbine from the steam may be applied as is desired. In the illustrated embodiments hereof, the use is to activate a pump. In no way is it intended that the concept be limited to pumps however as the extracted energy can be used for other devices.
While preferred embodiments have been shown and described, modifications and substitutions may be made thereto without departing from the spirit and scope of the invention. Accordingly, it is to be understood that the present invention has been described by way of illustrations and not limitation.
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A downhole arrangement including an outer housing, an inner housing disposed within the outer housing and defining with the outer housing a chamber, a turbine disposed within the chamber, and one or more nozzles disposed at the chamber capable of exhausting steam into the chamber. A method for moving a target fluid within a wellbore.
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CROSS-REFERENCE TO RELATED APPLICATION:
[0001] This application is a continuation of copending International Application No. PCT/DE99/02449, filed Aug. 6, 1999, which designated the United States.
BACKGROUND OF THE INVENTION
[0002] Field of the Invention
[0003] The invention relates to an apparatus containing a heat exchange cell for utilizing waste heat of an air-cooled fuel cell. The invention also relates to a method of rendering utilizable the waste heat of a fuel cell (FC) battery containing a stack of fuel cells.
[0004] German Patent DE 44 42 285 C1 describes an air-cooled polymer electrolyte membrane (PEM) fuel cell which contains a negative terminal plate, a negative electrode, a membrane, a positive electrode and a positive terminal plate. The two terminal plates (or separator plates) are joined, in a mechanically fixed, gas-tight and electronically insulating manner, to the membrane via a frame element. To protect the membrane against drying out, the process gases supplied are at least partially humidified. To this end, the process gases are passed through a humidifier, e.g. a membrane humidifier, in which they are admixed with evaporated water.
[0005] In the case of liquid-cooled fuel cells, the humidifiers are perfused by the spent liquid coolant and are heated thereby. The extraction of heat from the cooling air, however, is more problematic, and so far no suitable heat exchangers exist which render the heat required for evaporation available from the spent cooling air. With the air-cooled fuel cell it has therefore been necessary, hitherto, for such energy of evaporation to be raised externally.
[0006] Published, Japanese Patent Application JP 61-243662 A discloses blockwise air cooling of a complete fuel cell stack by interposed stacks of heat exchangers. Additionally, Japanese Patent Application JP 10-284107 A describes a fuel cell stack containing heat exchangers that directly adjoin the stack. Finally, Published Japanese Patent Application JP 57-157470 A proposes cooling plates for use in a fuel cell stack, wherein the cooling plates are integrated into the fuel cell stack. In general, partitions are provided for this purpose in the heat exchangers.
SUMMARY OF THE INVENTION
[0007] It is accordingly an object of the invention to provide an apparatus and a method for utilizing the waste heat of an air-cooled fuel cell battery which overcome the above-mentioned disadvantages of the prior art devices and methods of this general type, via which the waste heat of an air-cooled PEM fuel cell can be rendered utilizable with greater efficiency.
[0008] With the foregoing and other objects in view there is provided, in accordance with the invention, an apparatus for utilizing a waste heat of an air-cooled fuel cell. The apparatus includes a heat exchange cell containing at least two plates being end plates or separator plates and a thermally conductive plate disposed in relation to the two plates to enclose a first chamber and a second chamber. During operation the first chamber receives a spent cooling air, and a humidifier membrane is disposed in the second chamber and subdivides the second chamber into a first subchamber and a second subchamber. During operation the first subchamber receives water and the second subchamber receives a process gas to be humidified.
[0009] In accordance with an added feature of invention, the heat exchange cell directly adjoins the air-cooled fuel cell.
[0010] In the invention, a humidifier through which the process gases or a process gas for the fuel cell battery are passed, is integrated into a heat exchange cell. In this configuration, each heat exchange cell is of such construction that the first separator plate together with the thermally conductive contact plate encloses a gas chamber in which the spent cooling air is ducted from the fuel cell stack, and a second separator plate together with the contact plate encloses a second chamber in which a humidifier membrane is disposed centrally. The humidifier membrane, together with the contact plate, defines the chamber in which the water for humidification is heated via the contact plate by where the waste heat of the fuel cell stack and, together with the separator plate, delimits the chamber in which the process gas to be humidified is ducted.
[0011] In the method according to the invention of rendering utilizable the waste heat of an air-cooled fuel cell battery, the spent cooling air is passed through a stack of heat exchange cells and in the process gives off its heat. It is advantageous for the heat exchange cell for utilizing the waste heat to adjoin the fuel cell battery directly, so that no heat will be lost via intermediate lines.
[0012] With the foregoing and other objects in view there is further provided, in accordance with the invention, a method of using utilizable waste heat of an air-cooled cell battery containing a stack of fuel cells. The method includes providing an apparatus for utilizing the waste heat of the air-cooled cell battery. The apparatus includes a stack of heat exchange cells, each of the heat exchange cells contains at least two plates selected being end plates or separator plates, a thermally conductive plate disposed in relation to the two plates to enclose a first chamber and a second chamber; and a humidifier membrane disposed in the second chamber and subdividing the second chamber into a first subchamber and a second subchamber. The first subchamber receives water and the second subchamber receives a process gas to be humidified. Spent cooling air is conducted through the first chamber of the heat exchange cells, the spent cooling air giving off its heat to the water and the process gas.
[0013] In accordance with another mode of the invention, there is the step of setting a number of the heat exchange cells in the heat exchange cell stack to be identical to a number of fuel cells in stack of fuel cells.
[0014] Other features which are considered as characteristic for the invention are set forth in the appended claims.
[0015] Although the invention is illustrated and described herein as embodied in an apparatus and a method for utilizing the waste heat of an air-cooled fuel cell battery, it is nevertheless not intended to be limited to the details shown, since 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.
[0016] 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
[0017] [0017]FIG. 1 is a diagrammatic, cross-sectional view through a known heat exchange cell;
[0018] [0018]FIG. 2 is a cross-sectional view through the heat exchange cell according to the invention; and
[0019] [0019]FIG. 3 is a perspective view of a configuration containing a fuel cell stack with an adjoining heat exchange cell stack.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0020] In general, a cell referred to as a heat exchange cell contains at least two separator plates and a thermally conductive contact plate. These three plates are bonded together e.g. by a filter press technique, by lateral clamping, by a bead, by soldering or by cementing. The two separator plates are preferably made of an inexpensive, light and thermally conductive material, e.g. plastic or metal, from which they can be fabricated cost-effectively by processes suitable for mass production. Preferably, the separator plates have distribution channels like the corresponding terminal or separator plates of the fuel cell, in order to make available as large an area as possible for heat dissipation. The thermally conductive contact plate should likewise be embossed and/or molded and again be made of as inexpensive and light a material as possible, whose thermal conductivity directly codetermines the efficiency and the energetic benefit of the invention. The distribution channels can e.g. be flutes and/or grooves which are preferably debossed into the plates.
[0021] In all the figures of the drawing, sub-features and integral parts that correspond to one another bear the same reference symbol in each case. Referring now to the figures of the drawing in detail and first, particularly, to FIG. 1 thereof, there is shown the simplest form of a heat exchange cell 1 in cross section. At a top and a bottom is one separator plate 2 , 3 each, and in the center is a thermally conductive contact plate 4 . For the sake of simplicity, distribution channels, which are preferably also present, are not shown. The separator plate 2 , together with the contact plate 4 , encloses a chamber 5 through which spent cooling air is ducted. As a result, the contact plate 4 heats up even on a side that faces a further chamber 6 which is enclosed by the contact plate 4 together with the separator plate 3 . Present in the further chamber 6 is a medium to be heated, e.g. air in a passenger compartment of a vehicle propelled by PEM fuel cells. For safety reasons, the passenger compartment of these vehicles cannot be heated using the spent cooling air directly.
[0022] Preferably, a plurality of heat exchange cells are combined into a stack (e.g. by a filter press technique and/or soldered), which directly adjoins the fuel cell stack. A top side of the separator plate 2 then again borders a chamber, corresponding to the further chamber 6 , of the top heat exchange cell. Preferably, the separator plate 2 in this configuration will likewise be made from thermally conductive material to enable heat transfer from the separator plate 2 to the medium to be heated. In this case, both sides of the separator plates are preferably provided with distribution channels, which results in that a corrugated metal-like structure may possibly be advantageous. The edge seals and the conduits are non-critical, as long as the various gas and media chambers are separated from one another in a sufficiently impermeable manner.
[0023] Preferably, the contact plate 4 always has distribution channels on both sides. The medium to be heated is preferably air or water (e.g. as a stationary application for heating service water) or some other fluid. Equally, however, the heat exchange cell can be used for heating any type of medium.
[0024] [0024]FIG. 2 again shows a schematic cross section through the heat exchange cell 1 according to the invention. At the top, the separator plate 2 can again be seen which, together with the contact plate 4 , encloses the chamber 5 in which the spent cooling air is ducted. In this refinement of the invention, in which the spent cooling air is utilized to heat the humidifier, the further chamber 6 enclosed by the contact plate 4 together with the bottom separator plate 3 is subdivided by a humidifier membrane 7 . Flowing above the humidifier membrane 7 , in a chamber 6 b , is the water that is to be heated, and flowing below the humidifier membrane 7 , in a chamber 6 a , is the process gas that is to be humidified.
[0025] The humidifier membrane 7 is made of a water-permeable plastic or of some other water-conducting material. Of course, it can also be identical with a proton-conducting membrane from the fuel cell.
[0026] [0026]FIG. 3 shows a configuration of a fuel cell stack with an adjoining heat exchange cell stack. On the left-hand side of the picture there is a fuel cell stack 11 which is of prior art construction and at its front end plate has process gas inlets 14 , 16 and gas outlets 15 , 17 . The arrows in each case indicate a flow direction of the process gas (oxidizing agent and/or fuel), thus allowing the gas inlets 14 , 16 and the gas outlets 15 , 17 to be identified as such.
[0027] An arrow 13 indicates the direction in which the cooling air flows through the two stacks 11 and 12 , being heated in the fuel cell stack 11 and giving the heat off again in the heat exchange stack 12 .
[0028] Disposed adjoining the fuel cell stack 11 is the heat exchange cell stack 12 . In terms of construction it is almost identical with the fuel cell stack, except that it can be substantially simpler and less expensive in terms of insulation, electrical conductivity, material requirements (corrosion resistance etc.), without its functionality being impaired. Additionally, the heat exchange cell stack 12 has inlets and outlets at its end plate that is shown in the FIG. 3. For the embodiment shown, in which the heat exchange cells are integrated into a humidifier, there is an inlet 18 of the dry process gas, an outlet 19 of the humidified process gas, an inlet 20 of the humidification water and an outlet 21 of the humidification water.
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A heat exchange cell and to a method of utilizing the waste heat of an air-cooled fuel cell battery is described. The heat exchange cell is of a configuration similar to that of the fuel cell and, in the stack, should directly adjoin the fuel cell battery, so that the spent cooling air is utilized to heat a medium without an intermediate line.
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CROSS REFERENCE TO RELATED APPLICATIONS
This is a U.S. national stage of application No. PCT/CN2009/074304, filed on 29 Sep. 2009.
FIELD OF THE INVENTION
The present invention relates to a micro-irrigation technique for irrigating plants, and particularly, to an infiltration irrigation method, an infiltration irrigation apparatus and a method for manufacturing the same.
BACKGROUND OF THE INVENTION
In the drip irrigation and the infiltration irrigation at present, a most important problem is the blockage of the water outflow pores of the irrigator. In order to prevent the blockage, a common method is to perform a water treatment at the water supply end of the irrigation pipeline. However, this requires a very large investment on equipments, and the whole pipeline may be discarded due to any improper water treatment.
A diameter of the drip irrigation water outflow pore is generally between 0.5 and 1 mm, and the diameter of the infiltration irrigation water outflow pore is mainly from tens of microns to more than one hundred microns. It is found upon research that the blockage is caused by many impurities of different diameters within the above pore diameter ranges, and the particle diameter ranges from tens of microns to less than one micron. Careful studies show that the blockage process of these water outflow pores is as follows. The water in the pipe flows in an axial direction under pressure, wherein some water flows out in a radial direction through the water outflow pores, i.e., becomes irrigation water. Particles carried in the water with small diameters or diameters close to those of the water outflow pores form a bridge and block the outflow passage due to quick impact and drive by the water flowing by the water outflow pores. Thus smaller pores are remained near the bridge, while these pores will be further occupied by other particles or smaller particle bridges, and then are gradually blocked.
For this reason, it is necessary to provide an infiltration irrigation apparatus to solve or improve the problem of the blockage of the water outflow pores in the current drip irrigation and infiltration irrigation.
SUMMARY OF THE INVENTION
An object of the present invention is to provide an infiltration irrigation method, an infiltration irrigation apparatus and a method for manufacturing the same, which are capable of automatically clearing the obstructions by sufficiently utilizing the water flow to improve or prevent the blockage of the infiltration irrigation apparatus, prolong the service life of the infiltration irrigation apparatus, and reduce the use cost.
After repeated tests and studies of the water in the pipe, the inventor finds that when the diameter of the infiltration irrigation water outflow pore is small enough and the water outflow rate is sufficiently low, the impurities are difficult to block the outflow passage. Instead, they are slightly attached to the surfaces of the outflow pores, and then can be easily cleared by a shearing force generated by parallel water stream in the pipe. An anti-blockage and water-saving infiltration irrigation apparatus then can be manufactured by sufficiently utilizing such characteristic. The whole irrigation system adopting the infiltration irrigation apparatus can completely perform an automatic cleaning just using the water stream inside the irrigation pipeline, without needing any water treatment device, and will not be blocked during a long-term usage.
On the basis of the above principle, the present invention provides an infiltration irrigation apparatus including:
a water passing chamber having a water outlet and a water inlet, wherein a water stream along an axial direction of the water passing chamber is formed when the water flows between the water inlet and the water outlet;
one or more porous filter membranes disposed in the water passing chamber and formed with a filtration section for accommodating the water filtered by the one or more porous filter membranes; and the location of the one or more porous filter membrane is set so that at least a part of the water stream flows along a surface of the porous filter membrane to wash the surface when the axial water stream exists in the water passing chamber; and
one or more flow restrictors each disposed on a sidewall of the water passing chamber corresponding to the porous filter membrane, wherein each of the one or more flow restrictors has one or more restricting orifices, an inlet communicated with the filtration section of the one or more porous filter membranes and an outlet outside the water passing chamber, and a total water seepage capability of the one or more flow restrictors is smaller than that of the one or more porous filter membranes.
In a preferred example of the present invention, a maximum pore diameter of a restricting orifice of the flow restrictor is larger than that of the porous filter membrane.
In an optional embodiment of the present invention, the number of the one or more porous filter membranes is one, and one or more flow restrictors are disposed in correspondence to the porous filter membrane.
In another optional embodiment of the present invention, the number of the one or more porous filter membranes is more than one, and one or more flow restrictors are disposed in correspondence to each of the porous filter membranes.
In an optional embodiment of the present invention, the porous filter membrane covers a part of an inner wall of the water passing chamber, and edges of the porous filter membrane closely engage with the inner wall of the water passing chamber, so as to form the filtration section between the porous filter membrane and the inner wall of the water passing chamber covered thereby.
In another optional embodiment of the present invention, the porous filter membrane covers a complete circumference of an inner wall of the water passing chamber, and the edges of the porous filter membrane closely engage with the inner wall of the water passing chamber, so as to form the filtration section between the porous filter membrane and the inner wall of the water passing chamber covered thereby.
In yet another optional embodiment of the present invention, the porous filter membrane is bag-shaped, and the filtration section is formed in a bag of the porous filter membrane. In an example of this embodiment, the sidewall of the water passing chamber is disposed with an opening for engaging with the flow restrictor, the flow restrictor is inserted into the opening, a housing of the flow restrictor closely engages with edges of the opening, a bag mouth of the bag-shaped porous filter membrane closely engages with the inlet of the flow restrictor, so that the inlet of the flow restrictor is communicated with the filtration section. In a preferred example of this embodiment, the porous filter membrane has a flat bag shape, and the flat bag shaped porous filter membrane is set flush in the water passing chamber.
In still another optional embodiment of the present invention, the porous filter membrane and the flow restrictor are integrally formed with a same porous material. In this embodiment, the porous material may be porous ceramics.
In the present invention, the sidewall of the water passing chamber is disposed with an opening for engaging with the flow restrictor, an inlet of the flow restrictor closely engages with the opening, so as to dispose the flow restrictor on the sidewall of the water passing chamber; or the flow restrictor is directly mounted in the opening, so as to dispose the flow restrictor on the sidewall of the tubular water passing chamber.
In an optional embodiment of the present invention, the water passing chamber may be specifically formed in a tubular shape.
In an optional embodiment of the present invention, the water passing chamber is constituted by a water pipe or a part thereof, or a tubular support enclosed in the water pipe, and when the water flows in the water pipe, some flows in an axial direction of the water pipe and passes by a surface of the porous filter membrane to wash the surface, while some is filtered by the porous filter membrane, enters the flow restrictor through the filtration section, and flows out of the outlet of the flow restrictor to form irrigation water.
In an optional embodiment of the present invention, the number of the porous filter membranes is more than one, each of the porous filter membranes is disposed in a tubular support, and a plurality of tubular supports disposed with the porous filter membranes are enclosed in the water pipe, respectively, in the axial direction of the water pipe, so that the porous filter membranes are distributed in the water pipe.
In the present invention, the water pipe may be disposed with a valve or mounted with a micro pump actuated periodically, so that the water in the pipe moves to clear the impurities on the surface of the porous filter membrane.
In the present invention, the total water seepage capability of the porous filter membrane may be equal to or greater than five times of that of the corresponding one or more flow restrictors.
In the present invention, a maximum pore diameter of the restricting orifice may be equal to or greater than five times of that of the porous filter membrane.
The present invention further provides an infiltration irrigation method that uses the above infiltration irrigation apparatus, wherein one or more porous filter membranes are installed in a water passing chamber, and a filtration section is formed to accommodate the water filtered by the porous filter membrane; a sidewall of the water passing chamber corresponding to the location of each of the porous filter membranes is disposed with one or more flow restrictors, each of the flow restrictors has one or more restricting orifices, an inlet communicated with the filtration section of the porous filter membrane and an outlet outside the water passing chamber, and a total water seepage capability of the one or more flow restrictors is smaller than that of the one or more porous filter membranes; the water in the water passing chamber is made to flow axially at regular time so that an axial water stream flows along a surface of the porous filter membrane to wash the surface.
The present invention further provides a method for manufacturing the above infiltration irrigation apparatus, including:
A. providing one or more flow restrictors and one or more porous filter membranes, wherein each of the flow restrictors has one or more restricting orifices, and a total water seepage capability of the one or more flow restrictors is smaller than that of the one or more porous filter membranes;
B. correspondingly disposing the porous filter membrane and the flow restrictor on a plastic sheet having first and second longitudinal edges, wherein the porous filter membrane is located at an inner side of the plastic sheet and the flow restrictor is located at an outer side of the plastic sheet; a filtration section for accommodating the water filtered by the porous filter membrane is formed at a side where the porous filter membrane is located; and an inlet of the flow restrictor is communicated with the filtration section; and
C. engaging the first and second longitudinal edges of the plastic sheet with each other to form a tubular shape.
The present invention further provides a method for manufacturing the above infiltration irrigation apparatus, including:
A. providing one or more flow restrictors, one or more porous filter membranes, and a water passing chamber composed of a tubular support, wherein each of the flow restrictors has one or more restricting orifices, and a total water seepage capability of the one or more flow restrictors is smaller than that of the one or more porous filter membranes;
B. correspondingly disposing the porous filter membrane and the flow restrictor on the tubular support, wherein the porous filter membrane is located in a pipe of the tubular support; a filtration section for accommodating the water filtered by the porous filter membrane is formed; the flow restrictor is mounted on a sidewall of the tubular support in correspondence to the porous filter membrane; and an inlet of the flow restrictor is communicated with the filtration section of the porous filter membrane;
C. putting the tubular support having the porous filter membrane and the flow restrictor into a molding machine head during an extrusion molding of a water pipe, so that the tubular support is wrapped in the water pipe after the water pipe is extruded by the molding machine head; and
D. making a cut at a location corresponding to the outlet of the flow restrictor on the sidewall of the water pipe, so as to expose the outlet of the flow restrictor.
When the infiltration irrigation apparatus and the infiltration irrigation method of the present invention are adopted, since the total water seepage capability of the one or more flow restrictors is smaller than that of the one or more porous filter membranes, the total water outflow of the one or more flow restrictors is smaller than that of the one or more porous filter membranes, which reduces the amount of water penetrating the one or more porous filter membrane. Therefore, the water penetration rate of the porous filter membrane is reduced, and the impact speed of the impurities carried in the water on the porous filter membrane is decreased, so that the impurities are attached to the surface of the porous filter membrane very slightly. In addition, as the porous filter membrane is disposed in the water passing chamber, the surface of the porous filter membrane can be washed through the axial water stream in the water passing chamber, so that the impurities attached to the surface of the porous filter membrane very slightly are washed away by the water stream flowing along the surface of the porous filter membrane, which improves or avoids the blockage of the porous filter membrane, and effectively improves the blockage of the infiltration irrigation apparatus. Further, since the maximum pore diameter of the restricting orifice of the flow restrictor is preferably larger than that of the porous filter membrane, the restricting orifice will not be blocked when the water filtered by the porous filter membrane flows by the restricting orifice. Therefore, the infiltration irrigation apparatus of the present invention is very difficult to be blocked during the usage, and the service life of an infiltration irrigation system using such infiltration irrigation apparatus is far prolonged as compared with the case of adopting the infiltration irrigation apparatus of the prior art, which greatly reduces the use cost.
During the production of the infiltration irrigation apparatus of the present invention, the porous filter membrane and the flow restrictor may be directly engaged with the plastic sheet at first, and then the two longitudinal edges of the plastic sheet are engaged (by hot melting or gluing) with each other to form the plastic sheet into a tubular shape, which facilitates the continuous production of the tubular infiltration irrigation apparatus.
BRIEF DESCRIPTION OF THE DRAWINGS
In order to more clearly describe the technical solutions in the embodiments of the present invention or the prior art, the drawings needed for the descriptions of the embodiments or the prior art are briefly introduced as follows. It is obvious that the following drawings are just some embodiments of the present invention, and a person skilled in the art can acquire other drawings based on these drawings without paying any creative effort. Furthermore, these drawings are just exemplary, and do not limit the scales of various parts in the drawings.
FIG. 1 is a structural diagram of Embodiment 1 of the present invention;
FIG. 1A is another structural diagram of Embodiment 1 of the present invention;
FIG. 2 is a sectional diagram of FIG. 1 of the present invention;
FIG. 3 is a structural diagram of Embodiment 1 of the present invention in which one porous filter membrane is corresponding to a plurality of flow restrictors;
FIG. 4 is a structural diagram of Embodiment 1 of the present invention in which a plurality of porous filter membranes are disposed in a water passing chamber;
FIG. 5 is a structural diagram of Embodiment 1 of the present invention in which an entire porous filter membrane is disposed in an axial direction in the water passing chamber;
FIG. 6 is a schematic diagram of a manufacturing process of Embodiment 1 of the present invention;
FIG. 7 is a structural diagram of Embodiment 1 of the present invention in which the water passing chamber is a tubular support;
FIG. 8 is a schematic diagram of Embodiment 1 of the present invention in which an infiltration irrigation apparatus as illustrated in FIG. 7 is mounted into a water pipe or a part thereof;
FIG. 9 is a structural diagram of Embodiment 2 of the present invention;
FIG. 10 is a sectional diagram of FIG. 9 of the present invention;
FIG. 11 is a structural diagram of Embodiment 2 of the present invention in which a plurality of porous filter membranes are disposed in a water passing chamber;
FIG. 12 is a structural diagram of Embodiment 2 of the present invention in which an entire porous filter membrane is disposed in an axial direction in the water passing chamber;
FIG. 13 is a schematic diagram of a manufacturing process of Embodiment 2 of the present invention;
FIG. 14 is a structural diagram of Embodiment 3 of the present invention;
FIG. 14A is another structural diagram of Embodiment 3 of the present invention;
FIG. 14B is yet another structural diagram of Embodiment 3 of the present invention;
FIG. 15 is a sectional diagram of FIG. 14 of the present invention;
FIG. 16 is a structural diagram of Embodiment 3 of the present invention in which one porous filter membrane is corresponding to a plurality of flow restrictors;
FIG. 17 is a structural diagram of Embodiment 3 of the present invention in which a plurality of porous filter membranes are disposed in a water passing chamber;
FIG. 18 is a schematic diagram of Embodiment 3 of the present invention in which an infiltration irrigation apparatus using a tubular support as a water passing chamber is mounted into a water pipe or a part thereof;
FIG. 19 is schematic diagram of a mounting structure of Embodiment 3 of the present invention;
FIG. 20 is a schematic diagram of a manufacturing process of Embodiment 3 of the present invention;
FIG. 21 is a structural diagram of Embodiment 4 of the present invention;
FIG. 22 is a structural diagram of Embodiment 4 of the present invention in which one porous filter membrane is corresponding to a plurality of flow restrictors;
FIG. 23 is a structural diagram of Embodiment 4 of the present invention in which a plurality of porous filter membranes are disposed in a water passing chamber;
FIG. 24 is schematic diagram of Embodiment 4 of the present invention in which an infiltration irrigation apparatus using a tubular support as a water passing chamber is mounted into a water pipe or a part thereof; and
FIG. 25 is a schematic diagram of a manufacturing process of Embodiment 4 of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Other features, advantages and embodiments of the present invention will be illustrated or explained in the following descriptions, drawings and claims. In addition, it shall be appreciated that the above summary and the following descriptions are just exemplary, and they intend to provide further explanations, instead of limiting the scope of the present invention.
Through a large number of tests, the inventor finds that whether the water stream in a pipe can burst through impurity particles blocked in the water outflow passage depends on the adhesive force of the impurities on the water outflow passage. Meanwhile, the adhesive force of the impurities on the water outflow passage is directly influenced by the particle size and the “impact speed” of the impurities blocked on the water outflow pore when the impurities is carried by a radial water stream to the water outflow pore. That is, the faster the “impact speed” is, the deeper the location of the impurities blocked in the water outflow passage is, the larger the adhesive force is, and the impurities are not easy to be burst through by an axial parallel water stream. On the contrary, if the location of the impurities blocked in the water outflow passage is shallow, the adhesive force is small, and the impurities are easy to be burst through by a transverse water stream. Since the particle sizes of the impurities determine the “impact speed” of the impurities during the settlement in the water, the relation between the particle size and the settling speed is described as follow by taking the sediment particles as an example: the coarse sand with a particle diameter of 1 mm sinks at 1 m/s in the water, the fine sand with a particle diameter of 0.1 mm sinks at 8 mm/s, the fine soil with a particle diameter of 10 microns sinks at 0.154 mm/s, and the fine clay with a particle diameter of 1 micron sinks at 0.00154 mm/s The specific gravity of the clay particle is the same as that of the coarse sediment, and the great difference in settling speed is caused by the Brownian motion. The smaller the particle diameter of the impurities in the water is, the stronger the Brownian motion is. Thus, under the influence of the Brownian motion, the smaller impurities have a lower adhesive force on the water outflow pore. Such impurities will be displaced for a large distance even by a very slight water oscillation, and can be easily cleared by the water stream in the pipe.
On the other hand, even the porous filter membrane is not easy to be blocked due to the tiny particles of impurities are influenced by the Brownian motion, the blockage possibility may be greatly increased when the water penetrating the pores has a high water outflow rate, because the flow rate of the tiny particles carried in the water stream will also be increased.
Based on the above influence factors, the present invention provides an infiltration irrigation apparatus. As illustrated in FIGS. 1 to 25 , the infiltration irrigation apparatus of the present invention includes a water passing chamber 1 , one or more porous filter membranes 2 , and one or more flow restrictors 3 . In which, the water passing chamber 1 has a water inlet 11 and a water outlet 12 , and when the water flows between the water inlet 11 and the water outlet 12 , a water stream along an axial direction of the water passing chamber 1 will be formed in the water passing chamber 1 . The one or more porous filter membranes 2 are disposed in the water passing chamber 1 and formed with a filtration section 20 for accommodating the water filtered by the porous filter membrane 2 . The location of the porous filter membrane 2 is set so that when an axial water stream exists in the water passing chamber 1 , at least a part of the water stream flows along a surface of the porous filter membrane 2 to wash the surface. Each of the flow restrictors 3 is disposed on a sidewall of the water passing chamber 1 corresponding to the porous filter membrane 2 . Each of the flow restrictors 3 has one or more restricting orifices, an inlet communicated with the filtration section 20 of the porous filter membrane 2 and an outlet outside the water passing chamber 1 , and a total water seepage capability of the one or more flow restrictors 3 is smaller than that of the one or more porous filter membranes 2 .
The present invention further provides an infiltration irrigation method based on the above infiltration irrigation apparatus. In which, one or more porous filter membranes 2 are installed in a water passing chamber 1 and formed with a filtration section 20 for accommodating the water filtered by the porous filter membrane 2 . One or more flow restrictors 3 are disposed on a sidewall of the water passing chamber 1 corresponding to the location of each of the porous filter membranes 2 . Each of the flow restrictors 3 has one or more restricting orifices, an inlet communicated with the filtration section 20 of the porous filter membrane 2 and an outlet outside the water passing chamber 1 , and a total water seepage capability of the one or more flow restrictors 3 is smaller than that of the one or more porous filter membrane 2 . The water in the water passing chamber 1 is made to flow axially at regular time so that the axial water stream flows along a surface of the porous filter membrane 2 to wash the surface.
Thus, when an infiltration irrigation is carried out, the water is firstly filtered by the porous filter membrane 2 in the water passing chamber 1 and enters the filtration section 20 , then the water filtered by the filtration section 20 flows out through the flow restrictor 3 . Since the total water seepage capability of the one or more flow restrictors 3 is designed to be smaller than that of the one or more porous filter membranes 2 in the present invention, the total water outflow amount of the one or more flow restrictors 3 is smaller than that of the one or more porous filter membranes 2 , which reduces the amount of water penetrating the porous filter membrane 2 . Therefore, the water penetration rate of the porous filter membrane 2 is reduced, and the impact speed of the impurities carried in the water stream on the porous filter membrane 2 is decreased, so that the impurities are attached to the surface of the porous filter membrane 2 very slightly. In addition, as the porous filter membrane 2 is disposed in the water passing chamber 1 , the surface of the porous filter membrane 2 can be washed through the axial water stream in the water passing chamber 1 , so that the impurities attached to the surface of the porous filter membrane 2 very slightly are washed away by the water stream flowing along the surface of the porous filter membrane 2 , which improves or avoids a blockage of the porous filter membrane 2 , and effectively improves the blockage problem of the entire infiltration irrigation apparatus.
In the present invention, a maximum pore diameter of the restricting orifice of the flow restrictor 3 is preferably set to be larger than a maximum pore diameter of the porous filter membrane 2 (it can refer to Chinese national standard GB/T 1967-1996 for the method of measuring the maximum pore diameter). Thus a control may be carried out in the aspects of water penetration diameter and water seepage rate. Since the maximum pore diameter of the restricting orifice of the flow restrictor 3 is larger than that of the porous filter membrane 2 , the water filtered by the porous filter membrane 2 will not cause a blockage when flowing through the restricting orifice.
In the present invention, the maximum pore diameter may be defined as follows: a pore diameter corresponding to an intensity of pressure required for enabling the gas to pass through one end and a first bubble to occur at the other end after a porous substance is wetted by a liquid. The definitions of various pore diameters in the present invention may be acquired with reference to prior methods for measuring the pore diameter of the porous substance, and herein are not described in details.
As illustrated in FIG. 3 , a plurality of flow restrictors 3 may be disposed at the water outflow side corresponding to each of the porous filter membranes 2 , and each of the flow restrictors 3 has at least one restricting orifice. The total water outflow amount of these flow restrictors 3 is smaller than that of the porous filter membrane(s) 2 , i.e., the total water seepage of each flow restrictor 3 is smaller than that of corresponding porous filter membrane(s) 2 , and the water filtered by all the porous filter membrane(s) 2 will not flow out of the infiltration irrigation apparatus unless passing through these restricting orifices.
As mentioned above, the maximum pore diameter of the restricting orifice in the flow restrictor 3 is larger than that of the porous filter membrane 2 , so that the water filtered by the porous filter membrane 2 will not cause a blockage when passing through the restricting orifice. These restricting orifices function to reduce the amount of water penetrating the porous filter membrane 2 in a certain proportion upon demand, so as to decrease the water penetration rate of the porous filter membrane 2 . That is, the impact speed of the impurities carried in the water stream on the porous filter membrane 2 is decreased, so that the impurities are attached very slightly to the pores of the porous filter membrane 2 and can be easily washed away by the water stream. Such infiltration irrigation apparatus is suitable to a wide range of water supplying pressure, and the water outflow of the porous filter membrane 2 under a certain water supplying pressure may be controlled by selecting an appropriate number and appropriate pore diameters of restricting orifices. Thus the water has a sufficiently low penetration rate on the porous filter membrane 2 of a certain area where it penetrates, so as to ensure that the surface of the porous filter membrane 2 will not be blocked under the washing of the water stream of a low flow rate.
Preferably, the present invention uses a porous filter membrane 2 with the maximum pore diameter no more than 20 μm (more preferably 10 μm) as the water outflow passage for infiltration irrigation, so as to choose impurity particles having strong Brown motion characteristics to fit the pores of the porous filter membrane 2 . As a result, impurity particles capable of blocking the pores of the porous filter membrane 2 are not easily to be attached to the pores of the porous filter membrane 2 , and can be washed away by the water flowing along the surface of the porous filter membrane 2 . The particle diameters of smaller impurities are far less than the pores of the porous filter membrane 2 , and can easily pass through these pores without causing a blockage. Since large impurities will not be blocked in the membrane pores, the adhesive force is greatly reduced, and the impurities are easy to be washed away. Among even larger impurity particles there are many pores, and those impurities will not block the pores of the porous filter membrane 2 even stayed on the surface of the porous filter membrane 2 .
Thus, the present invention, by determining the diameters of pores of the porous filter membrane 2 , chooses out impurities having strong Brown motion characteristics as potential obstructions. In the meantime, the flow rate of water penetrating the porous filter membrane 2 is restricted by the flow restrictor 3 so as to decrease the “impact speed” of the obstruction. Under the influence of the Brown motion, the obstructions can only suspend on the surface of the porous filter membrane 2 , and can be easily carried away by the water stream on the surface of the porous filter membrane 2 , and the porous filter membrane 2 will nearly not be blocked by any particle. At the same time, the pore diameter of the flow restrictor 3 is larger than that of the porous filter membrane 2 , thus the flow restrictor 3 also will not be blocked. Therefore, the infiltration irrigation apparatus of the present invention is difficult to be blocked, and the service life of the entire irrigation system using the infiltration irrigation apparatus is greatly prolonged.
The water passing chamber 1 in the infiltration irrigation apparatus of the present invention may be formed in a tubular shape. As illustrated in FIGS. 1 , 4 and 5 , the water passing chamber 1 may be constituted by a water pipe 10 or a part thereof, or may be a tubular support enclosed in the water pipe as illustrated in FIGS. 6 and 7 . Thus, when water flows in the water pipe, some flows in the axial direction of the water pipe and passes by the surface of the porous filter membrane 2 to wash the surface, while some is filtered by the porous filter membrane 2 , enters the flow restrictor 3 through the filtration section 20 , and flows out of the outlet of the flow restrictor 3 to form irrigation water.
When the infiltration irrigation apparatus of the present invention is used, the water in the water passing chamber 1 may be enabled to flow axially at regular time, so as to periodically clear the impurities on the surface of the porous filter membrane 2 in the water passing chamber 1 . The flow of water stream in the water passing chamber 1 may be implemented in various manners. For example, one end of the water pipe is provided with a valve or micro pump, and the water in the whole pipe will flow when some water is discharged by opening the valve or the water is pumped by the other end of the micro pump, so as to form an axial water stream in the water passing chamber 1 . Such axial flow of the water stream in the water passing chamber 1 may effectively wash the porous filter membrane 2 , so that the impurities stayed thereon will be displaced and cannot block the pores of the porous filter membrane 2 , thus a long-time and stable operation of the entire irrigation system is ensured. Or, when the water pipe is an annular (circular, elliptical, rectangular or the like) structure, a micro pump may also be mounted on the pipe, so as to make the water in the pipe move periodically, and continuously clear the impurities on the porous filter membrane 2 . Thus the membrane is ensured to be unobstructed and the flow restrictor 3 will not be blocked, and the entire irrigation system can operate stably in a long term.
In the present invention, the restricting orifices of the flow restrictor 2 may be formed in various manners. For example, a porous medium having a capillary function or capillary tube bundles may be disposed in the flow restrictor 2 to form a plurality of restricting orifices. Of course, the restricting orifices may also be formed in other manners known by persons skilled in the art, and herein is not limited.
During the actual operation, a manner may also be adopted in which the average or minimum pore diameter of the restricting orifice is larger than the maximum pore diameter of the porous filter membrane, which is more favorable to prevent the flow restrictor from being blocked (it can refer to Chinese national standard GB/T 1967-1996 for the method of measuring the average and minimum pore diameters).
Preferably, the maximum pore diameter of the restricting orifice 3 is chosen to be equal to or greater than 5 times of that of the porous filter membrane 2 . Or even preferably, the maximum pore diameter of the restricting orifice 3 is chosen to be equal to or greater than 10 times of that of the porous filter membrane 2 . The definitive relation between the pore diameters of the restricting orifice and the porous filter membrane 2 solves the problem that the restricting orifice is easy to be blocked.
The larger the difference between the water seepage capabilities of the flow restrictor 3 and the porous filter membrane 2 is, the slower the water seepage rate of the porous filter membrane 2 is, the smaller the “impact speed” of the impurity is, and the longer the service life of the porous filter membrane 2 . Thus, in order to manufacture an infiltration irrigation apparatus of an ultra-long service life, works of the following two aspects shall be done after the pore diameter of the porous filter membrane 2 has been determined: on one hand, the water outflow of the flow restrictor 3 is decreased so far as possible on the condition that the water amount needed by the plants is satisfied, by reducing the number of the restricting orifices or the pore diameter thereof (not less than that of the porous filter membrane); on the other hand, water seepage capability of the porous filter membrane 2 is enhanced so far as possible by increasing the seepage area. Thus, an infiltration irrigation apparatus can be manufactured to work in long term using any water.
The embodiments of the infiltration irrigation apparatus of the present invention are described as follows with reference to the drawings, so as to further describe the infiltration irrigation apparatus and the method for manufacturing the same. To be noted, all the drawings are just illustrative and not drafted in scales. In the drawings, the same reference signs are used to denote the same or similar components.
Embodiment 1
FIGS. 1 to 8 illustrate the structural diagrams of the infiltration irrigation apparatus according to Embodiment 1 of the present invention. As illustrated in FIG. 1 , the infiltration irrigation apparatus according to the embodiment includes a water passing chamber 1 , a porous filter membrane 2 and a flow restrictor 3 . The water passing chamber 1 has a water inlet 11 and a water outlet 12 . The porous filter membrane 2 covers a complete circumference of inner wall of the water passing chamber 1 . The edges of both ends of the porous filter membrane 2 may closely engage with the inner wall of the water passing chamber 1 and then become waterproof, so as to form a filtration section 20 between the porous filter membrane 2 and the inner wall of the water passing chamber 1 covered thereby. The flow restrictor 3 is disposed on a sidewall of the water passing chamber 1 corresponding to the porous filter membrane 2 . Each flow restrictor 3 has one or more restricting orifices, an inlet communicated with the filtration section 20 of the porous filter membrane 2 and an outlet outside the water passing chamber 1 . The total water seepage capability of the flow restrictor 3 is smaller than that of the porous filter membrane 2 .
Thus as illustrated in FIGS. 1 to 8 , since the porous filter membrane 2 covers the complete circumference of inner wall of the water passing chamber 1 , when an infiltration irrigation for plants is carried out, the water in the water passing chamber 1 will be filtered by the porous filter membrane 2 , enter the filtration section 20 between the porous filter membrane 2 and the inner wall of the water passing chamber 1 , and flow out through the restricting orifice of the flow restrictor 3 , so as to form irrigation water for irrigating plants. Since the total water seepage capability of the flow restrictor 3 is smaller than that of the porous filter membrane 2 , i.e., the total water outflow amount of the flow restrictor 3 is smaller than that of the porous filter membrane 2 , the water penetrating the porous filter membrane 2 flows very slowly. After the infiltration irrigation apparatus is used for some time, the impurities in water will only be slightly attached to the porous filter membrane 2 . In that case, by making water in the water passing chamber 1 flow axially, the axial water stream passing by the water passing chamber 1 will flow along the surface of the porous filter membrane 2 , so as to wash impurities on the porous filter membrane 2 , and effectively prevents the porous filter membrane 2 from being blocked.
In this embodiment, the maximum pore diameter of the restricting orifice of the flow restrictor 3 is preferably larger than that of the porous filter membrane 2 . Thus, the restricting orifice of the flow restrictor 3 will not be blocked during the infiltration irrigation since the maximum pore diameter of the restricting orifice of the flow restrictor 3 is larger than that of the porous filter membrane 2 .
In this embodiment, the porous filter membrane 2 may be directly disposed on the inner wall of the water passing chamber 1 by welding or compression joint, so that the water stream flows on the porous filter membrane 2 and the wash effect is the optimum.
As illustrated in FIGS. 1 and 3 , the flow restrictor 3 may be composed of one or more restricting orifices. The flow restrictor 3 may be directly opened on the pipe wall in the range covered by the porous filter membrane 2 , or the restricting orifice may be extended outside the infiltration irrigation apparatus by appropriately extending the flow restrictor 3 . As illustrated in FIG. 1 , in this embodiment, the sidewall of the water passing chamber 1 may be disposed with an opening for engaging with the flow restrictor 3 . The flow restrictor 3 may be directly mounted in the opening to dispose the flow restrictor 3 on the sidewall of the tubular water passing chamber 1 . The mounting of the flow restrictor 3 in the opening of the water passing chamber 1 may be specifically as follows: the flow restrictor 3 is made of porous ceramics and inserted into the opening with its outer wall closely engaging with the opening edge; or the flow restrictor 3 is made of several hydrophilic fibers directly disposed in the opening with their ends extending outside, so as to form a mounting structure for the flow restrictor 3 and the opening. As illustrated in FIG. 1A , the inlet of the flow restrictor 3 may be closely engaged with the opening to dispose the flow restrictor 3 on the sidewall of the water passing chamber 1 .
As illustrated in FIGS. 1 and 2 , in this embodiment, each porous filter membrane 2 may be correspondingly disposed with one flow restrictor 3 , or as illustrated in FIGS. 3 and 5 , each porous filter membrane 2 is corresponding to two or more flow restrictors 3 , so as to distribute the irrigation water to different irrigation locations. Under the same pressure and time, the water outflow amounts of the porous filter membrane 2 are measured and the water outflow amounts of the one or more flow restrictors 3 in the range covered by the porous filter membrane 2 are measured, and the total water seepage amount of the one or more flow restrictors 3 shall be smaller than that of the porous filter membrane 2 , i.e., the total water seepage capability of the one or more flow restrictors 3 is smaller than that of the porous filter membrane 2 . Thus the flow restrictor 3 limits the water seepage rate of the porous filter membrane 2 , and reduces the “impact speed” of impurities in the water on the porous filter membrane 2 . So the impurities on the surface of the porous filter membrane 2 are easier to be cleared by the water stream, which greatly prolongs the service life of the porous filter membrane.
In this embodiment, as illustrated in FIGS. 1 , 4 , 5 and 8 , the water passing chamber 1 may be constituted by a water pipe 10 or a part thereof. As illustrated in FIG. 4 , a plurality of porous filter membranes 2 may be disposed in the axial direction of the water pipe 10 or a part thereof. Or as illustrated in FIG. 5 , a whole porous filter membrane 2 is extendedly disposed in the axial direction of the water pipe 10 or a part thereof, and a plurality of flow restrictors 3 are disposed in correspondence to the porous filter membrane 2 , so as to irrigate plants at different locations.
As illustrated in FIGS. 7 and 8 , the water passing chamber 1 may also be a tubular support enclosed in the water pipe 10 . An infiltration irrigation apparatus having such a water passing chamber 1 composed of a tubular support may be manufactured in the following steps:
A. providing one or more flow restrictors 3 , one or more porous filter membranes 2 , and a water passing chamber 1 composed of a tubular support, wherein each flow restrictor 3 has one or more restricting orifices, and the total water seepage capability of the one or more flow restrictors 3 is smaller than that of the one or more porous filter membranes 2 ;
B. correspondingly disposing the porous filter membrane 2 and the flow restrictor 3 on the tubular support, wherein the porous filter membrane 2 is located in the pipe of the tubular support; a filtration section 20 for accommodating water filtered by the porous filter membrane 2 is formed; the flow restrictor 3 is mounted on the sidewall of the tubular support in correspondence to the porous filter membrane 2 ; and an inlet of the flow restrictor 3 is communicated with the filtration section 30 of the porous filter membrane 2 ;
C. putting the tubular support having the porous filter membrane 2 and the flow restrictor 3 into a molding machine head during an extrusion molding of a water pipe 10 , so that the tubular support is wrapped in the water pipe 10 after the water pipe 10 is extruded by the molding machine head; and
D. making a cut at a location corresponding to an outlet of flow restrictor 3 on the sidewall of the water pipe 10 , so as to expose the outlet of the flow restrictor 3 and form an infiltration irrigation apparatus as illustrated in FIG. 8 .
Thus, when water flows in the water pipe, some flows in the axial direction of the water pipe and passes by the surface of the porous filter membrane 2 to wash the surface, while some is filtered by the porous filter membrane 2 , enters the flow restrictor 3 through the filtration section 20 , and flows out of the outlet of the flow restrictor 3 to form irrigation water.
Upon the irrigation demand, the water pipe 10 or a part thereof may be a main water pipe in the irrigation system, or a plurality of branches connected to the main water pipe, and herein is not limited.
The flow of water stream in the water passing chamber 1 may be implemented in various manners. For example, one end of the water pipe is provided with a valve or micro pump, and the water in the whole pipe will flow when some water is discharged by opening the valve or the water is pumped by the other end of the micro pump upon demand, so as to form an axial water stream in the water passing chamber 1 . For a short water passing chamber 1 or water pipe, a pushable piston may be disposed at the location of a water inlet 11 . When the porous filter membrane 2 needs to be cleaned, the piston is pushed to make the water in the water passing chamber 1 or the water pipe flow, so as to wash the surface of the porous filter membrane 2 .
During the production of such infiltration irrigation apparatus, it is inconvenient to mount the porous filter membrane 2 and the flow restrictor 3 in the narrow tube, and there are many inconveniences in implementation with prior producing methods. The infiltration irrigation apparatus of the present invention may be manufactured by using the following method, in addition to the manner as illustrated in FIGS. 7 and 8 in which a tubular support having the porous filter membrane 2 and the flow restrictor 3 is firstly formed and then put into the water pipe:
A. molding a flow restrictor 3 having one or more restricting orifices;
B. engaging one or more flow restrictors 3 with a plastic sheet 13 having first and second longitudinal edges 131 , 132 , as illustrated in FIG. 6 ;
C. providing a porous filter membrane 2 such that the total water seepage capability of the one or more flow restrictors 3 is smaller than that of the porous filter membrane 2 ;
D. making one or more porous filter membranes 2 to at least cover an inner wall of the plastic sheet 13 corresponding to the flow restrictor 3 , so as to form the filtration section between the porous filter membrane 2 and the inner wall covered thereby, as illustrated in FIG. 6 ; and
E. engaging the first longitudinal edge of the plastic sheet 10 with the second longitudinal edge of the plastic sheet 10 to form a tubular shape, as illustrated in FIG. 6 .
The steps C and D may be performed before the steps A and B, i.e., the porous filter membrane 2 may be connected to the plastic sheet 13 firstly, then the flow restrictor 3 is engaged with the plastic sheet 13 , and limitation is not made in the present application. Furthermore, in step A, the flow restrictor 3 may be an independent product, or directly formed by molding the porous medium or capillary tubes at the opening of the plastic sheet 10 , and herein is not limited.
Thus in this embodiment, the porous filter membrane 2 and the flow restrictor 3 may be directly engaged with the plastic sheet 13 at first in the production, and then the first and second longitudinal edges 131 and 132 of the plastic sheet are engaged (by hot melting or gluing) with each other to form the plastic sheet 13 into a tubular shape, so as to facilitate the continuous production of the tubular infiltration irrigation apparatus.
Embodiment 2
FIGS. 9 to 13 illustrate structural diagrams of Embodiment 2 of the present invention. The basic structure of this embodiment is substantially the same as that of Embodiment 1, the descriptions of the same portions are omitted herein, and the difference is the manner of disposing the porous filter membrane 2 . In this embodiment, provided that the total water seepage capability of the porous filter membrane 2 is larger than that of the flow restrictor 3 , the porous filter membrane 2 may be just disposed on a part of the circumference of the inner wall of the water pipe 1 , i.e., it only covers a part of the inner circumferential wall of the water passing chamber 1 corresponding to the flow restrictor 3 . In addition, the edges of the porous filter membrane 3 closely engage with the inner of the water pipe to proof water, so as to form an isolated filtration section 20 between the porous filter membrane 2 and the inner wall of the water pipe covered thereby. The water cannot become irrigation water until it enters the filtration section 20 through the porous filter membrane 2 and flows out through the flow restrictor. The water stream in the water pipe functions to clear impurities when passing by the surface of the porous filter membrane 2 .
In this embodiment, as illustrated in FIG. 9 , each porous filter membrane 2 may be correspondingly disposed with a flow restrictor 3 . Or as illustrated in FIGS. 11 and 12 , each porous filter membrane 2 may be corresponding to two or more flow restrictors 3 , so as to distribute the irrigation water to different irrigation locations.
In this embodiment, as illustrated in FIGS. 9 , 11 and 12 , the water passing chamber 1 may be constituted by a water pipe 10 or a part thereof. As illustrated in FIG. 11 , a plurality of porous filter membranes 2 may be disposed in the axial direction of the water pipe 10 or a part thereof. Or as illustrated in FIG. 12 , a whole porous filter membrane 2 is extendedly disposed in the axial direction of the water pipe 10 or a part thereof, and a plurality of flow restrictors 3 are disposed in correspondence to the porous filter membrane 2 , so as to irrigate plants at different locations. Upon the irrigation demand, the water pipe 10 or a part thereof may be a main water pipe in the irrigation system, or a plurality of branches connected to the main water pipe, and herein is not limited.
In this embodiment, being similar to illustrations of FIGS. 7 and 8 in Embodiment 1, the water passing chamber 1 may be a tubular support enclosed in the water pipe 10 (not shown). The manufacturing method thereof can also be the same as that in Embodiment 1, and herein is omitted.
In this embodiment, the flow of water stream in the water passing chamber 1 may also be implemented in various manners. For example, one end of the water pipe is provided with a valve or micro pump, and the water in the whole pipe will flow when some water is discharged by opening the valve or the water is pumped by the other end of the micro pump upon demand, so as to form an axial water stream in the water passing chamber 1 . For a short water passing chamber 1 or water pipe, a pushable piston may be disposed at the location of a water inlet 11 . When the porous filter membrane 2 needs to be cleaned, the piston is pushed to make water in the water passing chamber 1 or the water pipe flow, so as to wash the surface of the porous filter membrane 2 .
During the production of such infiltration irrigation apparatus, it is inconvenient to mount the porous filter membrane 2 and the flow restrictor 3 in the narrow tube, and there are many inconveniences in implementation with the prior producing methods. Being similar to Embodiment 1, in addition to the manner as illustrated in FIGS. 7 and 8 in which a tubular support having the porous filter membrane 2 and the flow restrictor 3 is firstly formed and then put into the water pipe, the following method may be adopted: as illustrated in FIG. 13 , the porous filter membrane 2 and the flow restrictor 3 may be firstly disposed on the plastic sheet 13 having the first and second longitudinal edges 131 and 132 , and then the first and second longitudinal edges 131 and 132 of the plastic sheet 13 are engaged (by hot melting or gluing) with each other to form the plastic sheet 13 into a tubular shape, so as to facilitate the continuous production of the tubular infiltration irrigation apparatus.
Since the embodiment has a structure substantially the same as that of Embodiment 1, the technical effect of Embodiment 1 will also be achieved, and herein is omitted.
Embodiment 3
FIGS. 14 to 19 illustrate structural diagrams of Embodiment 3 of the present invention. The basic structure and the principle of this embodiment are substantially the same as that of Embodiment 1, and the descriptions of the same portions are omitted herein. As illustrated in FIGS. 14 to 19 , this embodiment differs from Embodiment 1 in that the porous filter membrane 2 is bag-shaped, and the filtration section 20 is formed in a bag of the porous filter membrane 2 . During the infiltration irrigation, the water cannot become irrigation water until it enters the bag through the bag-shaped porous filter membrane 2 (i.e., into the filtration section 20 ), and flows out of the tubular infiltration irrigation apparatus through the flow restrictor 3 .
In addition to the effect of Embodiment 1, since a bag-shaped porous filter membrane 2 is used, a blockage is more difficult to be caused. Because firstly, as compared with the flush porous filter membrane, the bag-shaped porous filter membrane 2 can multiply the membrane area in a narrow space, reduce the adhesive force of impurities, and prolong the membrane life. Secondly, once water flows in the pipe, a pressure will be produced in a part of region of the bag of the porous filter membrane 2 ; such pressure is transferred to the water in the bag and causes a liquid pressure outward from the inside of the bag; and some water flows outwards from the inside of the bag through the pores on the membrane, so as to produce a certain effect of backwash and prolong the membrane life.
As illustrated in FIGS. 14A and 14B , in this embodiment, the porous filter membrane 2 and the flow restrictor 3 may be disposed on the water passing chamber 1 in a manner similar to that of Embodiment 1. The bag mouth edges of the porous filter membrane 2 closely engage with the inner wall of the water passing chamber 1 , an opening for engaging with the flow restrictor 3 is disposed at a location on the sidewall of the water passing chamber 1 corresponding to the bag mouth of the porous filter membrane 2 , and the inlet of the flow restrictor 3 may directly and closely engage with the opening on the sidewall of the water passing chamber 1 as illustrated in FIG. 14A , or as illustrated in FIG. 14B , the flow restrictor 3 is mounted in the opening with its outer wall engaging with the opening edges. As illustrated in FIG. 14 , in this embodiment, the bag mouth of the porous filter membrane 2 may be fixedly and closely engaged with the inlet edge of the flow restrictor 3 at first, so that the inlet of the flow restrictor 3 is communicated with the filtration section 20 ; and then the flow restrictor 3 having a membrane bag is fixed by plugging from inside to outside and sealed at the opening of the water passing chamber 1 . This mounting manner is simple and convenient, in which the flow restrictor 3 may have an inverted cone shape so as to be conveniently plugged at the opening of the water passing chamber 1 . Further as illustrated in FIG. 19 , the upper portion of the flow restrictor 3 may have a neck. During the mounting, the bag mouth of the membrane bag is fixedly and closely engaged with the opening of the water passing chamber 1 , then the flow restrictor 3 is inserted into the opening from outside the water passing chamber 1 , and the neck of the flow restrictor 3 is clamped and fixed at the opening, finally is sealed. Preferably, the opening of the water passing chamber 1 is made of a material (e.g., rubber) of a good elasticity for the convenience of mounting and ensuring the sealing effect.
In this embodiment, the porous filter membrane 2 is preferably in a flat bag shape, and the flat bag-shaped porous filter membrane 2 is set flush in the water passing chamber 1 , which can effectively increase the area of the porous filter membrane 2 , and will not cause too large a resistance to the water stream in the pipe.
In this embodiment, each porous filter membrane 2 may be provided with a flow restrictor 3 as illustrated in FIG. 14 ; or as illustrated in FIG. 16 , each porous filter membrane 2 is corresponding to two or more flow restrictors 3 , so as to distribute the irrigation water to different irrigation locations.
In this embodiment, as illustrated in FIGS. 14 , 17 and 18 , the water passing chamber 1 may be constituted by a water pipe 10 or a part thereof. As illustrated in FIGS. 17 and 18 , a plurality of porous filter membranes 2 may be disposed along the axial direction of the water pipe 10 or a part thereof. Upon the irrigation demand, the water pipe 10 or a part thereof may be a main water pipe in the irrigation system, or a plurality of branches connected to the main water pipe, and herein is not limited.
In this embodiment, as illustrated in FIG. 18 , the water passing chamber 1 may be a tubular support enclosed in the water pipe 10 similar to that as illustrated in FIGS. 7 and 8 of Embodiment 1. The manufacturing method thereof may be the same as that of Embodiment 1, and herein is omitted.
In this embodiment, the flow of water stream in the water passing chamber 1 may be implemented in various manners. For example, one end of the water pipe is provided with a valve or micro pump, and the water in the whole pipe will flow when some water is discharged by opening the valve or the water is pumped by the other end of the micro pump upon demand, so as to form an axial water stream in the water passing chamber 1 . For a short water passing chamber 1 or water pipe, a pushable piston may be disposed at the location of a water inlet 11 . When the porous filter membrane 2 needs to be cleaned, the piston is pushed to make water in the water passing chamber 1 or the water pipe flow, so as to wash the surface of the porous filter membrane 2 .
During the production of such infiltration irrigation apparatus, it is inconvenient to mount the porous filter membrane 2 and the flow restrictor 3 in the narrow tube, and there are many inconveniences in implementation with the prior producing methods. Being similar to Embodiment 1, in addition to the manner as illustrated in FIGS. 7 and 8 in which a tubular support having the porous filter membrane 2 and the flow restrictor 3 is firstly formed and then put into the water pipe, the following method may be adopted: as illustrated in FIG. 20 , the porous filter membrane 2 and the flow restrictor 3 may be firstly disposed on the plastic sheet 13 having the first and second longitudinal edges 131 and 132 , and then the first and second longitudinal edges 131 and 132 of the plastic sheet 13 are engaged (by hot melting or gluing) with each other to form the plastic sheet 13 into a tubular shape, so as to facilitate the continuous production of the tubular infiltration irrigation apparatus.
Since the embodiment has a structure substantially the same as Embodiment 1, the technical effect of Embodiment 1 will also be achieved, and herein is omitted.
Embodiment 4
FIGS. 21 to 25 illustrate structural diagrams of Embodiment 4 of the present invention. The basic structure and the principle of this embodiment are substantially the same as the preceding embodiments, and the descriptions of the same portions are omitted herein. In which as illustrated in FIGS. 21 to 25 , this embodiment differs from the preceding embodiments as follows: in preceding Embodiments 1 to 3, the porous filter membrane 2 and the flow restrictor 3 are not integrally formed and may be formed of different materials, e.g., the porous filter membrane 2 is made of nylon membrane, and the flow restrictor 3 is made of hydrophilic fibers or porous material; while in this embodiment, the porous filter membrane 2 and the flow restrictor 3 are formed integrally with the same porous material (e.g., porous ceramics), i.e., the upper portion of the flow restrictor 3 becomes the porous filter membrane 2 of a large area so that the porous filter membrane 2 itself forms a filtration section 20 isolated from the water passing chamber 1 , and the bottom of the porous filter membrane 2 extrudes integrally to form the flow restrictor 3 . In addition, the thickness and area of the porous filter membrane 2 may be set according to the filtration demands.
In this embodiment, the total water seepage capability of the porous filter membrane 2 may be larger than that of one or more flow restrictors 3 by setting the water seepage surface of the porous filter membrane 2 to be larger than the total water outflow area of the one or more flow restrictors 3 , so as to restrict the flow rate of the water penetrating the porous filter membrane 2 .
The integral structure of the porous filter membrane 2 and the flow restrictor 3 has a small water outflow area outside the water passing chamber 1 , while a far larger volume and a quite larger surface inside the water passing chamber 1 . Thus the water outlet at the outside actually functions to restrict the water stream, and the water penetration rate on the large surface inside is very slow. The “impact speed” of impurities is slower correspondingly, which is very beneficial for clearing the impurities. The porous filter membrane 2 and the flow restrictor 3 made of an integral material are easier for manufacturing and mounting, and have a reduced cost.
In this embodiment, an opening may be pre-disposed on the water passing chamber 1 , and the water outlet of the flow restrictor 3 may be inserted from the inside to the outside through the opening and then fixed and sealed. Alternatively, the flow restrictor 3 may be screwed on the sidewall of the water passing chamber 1 by its housing.
As illustrated in FIG. 25 , the method for manufacturing the infiltration irrigation apparatus is easier than that of Embodiment 1. It only needs to molding the porous filter membrane 2 and the flow restrictor 3 integrally formed with a same material (e.g., porous ceramics), and then engaging them with the plastic sheet. It can refer to Embodiment 1 for other portions.
In this embodiment, as illustrated in FIG. 24 , the water passing chamber 1 may also be a tubular support enclosed in the water pipe 10 . The manufacturing method thereof may be the same as that of Embodiment 1, and herein is omitted.
Although the embodiments disclose the present invention, they do not intend to limit the present invention. Any replacement of equivalent assembly made by a person skilled in the art without deviating from the concept and scope of the present invention, or any equivalent change and modification made according to the patent protection scope of the present invention, shall be covered by the present patent application.
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A filtration irrigation method, filtration irrigation device and the manufacturing method thereof, said filtration irrigation device comprises a water carrying chamber, in which one or more porous filter membranes are arranged. One or more flow restrictors corresponding to each membrane are set on the wall of the water carrying chamber. The total permeation capacity of the flow restrictors is less than that of said filter membranes. The present invention can avoid the blockage of the device effectively.
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BACKGROUND OF THE INVENTION
The present invention relates to an improvement of an apparatus for processing semiconductor substrates (hereinafter referred to as wafers), or any other plates, such as glass plates. More particularly, the present invention relates to an improvement of an apparatus for use, wherein the apparatus is adapted for use in a rinse processing and a dry processing.
To dry wafers by rotation thereof, there have been several proposals, among which Japanese patent application Laid-Open No. 57-183038 shows such an apparatus as depicted in FIG. 4, which is discussed in detail below.
The well known apparatus depicted in FIG. 4 comprises a housing 101 which defines a drying chamber 102 therein. A rotary member 106 is rotatably provided in the chamber 102, and is fixedly supported by a shaft 109. On the rotary member 106 a couple of wafer cases 107 are detachably mounted, wafers to be processed being stored horizontally in the wafer cases. A lid 103 is provided on the top of the housing 101, the lid 103 having an opening 104 through which dry air is introduced into the chamber. The conventional apparatus further comprises a cylindrical inner wall 108 extending downwardly from the lid 103 up to slightly below the upper margin of the rotary member 106 so that the upper margin is surrounded by the inner wall 108. When a dry processing is carried out, the rotary member 107 in which wafers to be processed are stored is rotated at high speed, during which dry air is introduced into the chamber, through the opening 104. The dry air introduced is used for drying the wafers, and thus-used air is expelled through an exhaust duct 105 which is pneumatically connected to the chamber. The flow of air is depicted by arrows in FIG. 4.
In the conventional apparatus as mentioned above the cylindrical inner wall 108 is intended to function as a barrier to prevent undesirable water and dirt from entering into the inside of the rotary member 106, that is, from contaminating the wafers to be processed thereby.
However, there remains a problem that eddy flows denoted by the numeral 103a may be caused in the upper peripheral portion within the chamber denoted by the letter C, where desirable water and dirt expelled from the rotary member 106 will accumulate and disadvantageously enter into the inside of the rotary member through a space between the inner wall 108 and the rotary member, because the rotation thereof causes a negative pressure inside the member 106. The wafers to be processed and stored in the cases 107 can be contaminated and spoiled.
OBJECTS AND SUMMARY OF THE INVENTION
The present invention is directed toward solving the aforementioned problem of the conventional apparatus. Specifically, it is a primary object of this invention to provide an improved apparatus for processing wafers by rotation thereof, so as to avoid possible contamination of the wafers, and so as to secure speedy and safe processing thereof.
Other objects and advantages of the present invention will become apparent from the detailed description of preferred embodiments taken in conjunction with the accompanying drawings. It should be understood, however, that the description and specific embodiments be given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art the present invention pertains.
To achieve the foregoing object, there is provided, in one embodiment of the present invention, an apparatus for processing wafers or the like by rotation thereof. This apparatus comprises: a housing which defines a processing chamber therein; an exhaust duct connected to the lower side portion of the chamber; a rotary member rotatably mounted within the chamber, on which a plurality of wafers to be processed are held; barrier means for preventing undesired objects from entering into the inside of the rotary member, the barrier extending downwardly up to immediately adjacent to the rotary member; a lid member openably mounted at the top of the housing, the lid member having an opening for introducing clean air or the like into the chamber; an auxiliary chamber provided at the upper peripheral portion within the processing chamber; and an auxiliary duct connected to the auxiliary chamber. The auxiliary chamber is preferably provided at the position outside the barrier means and within the outer wall of the processing chamber.
The barrier means preferably comprises a cylindrical or partially conical plate mounted immediately above the rotary member.
On the rotary member at least one wafer cassette holder is pivotably mounted, the holder being adapted to receive a wafer cassette in which a plurality of wafers to be processed are stored. The holder is movable from the first position to the second position, where a wafer cassette is loaded in the holder.
Preferably, a circular plate is mounted on the top of the rotary member, by which undesired objects are prevented from entering into the inside of the rotary member. Clean air is introduced into the inside of the rotary member through the opening of the circular plate.
An air filter is preferably provided immediately beneath the lid member.
A conduit substantially vertically extends at the center of the rotary member, at the peripheral surface of which fine holes are provided so as to supply desired solution or gas to the wafers.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a vertical cross-section of a first embodiment of the present invention;
FIG. 2 is a cross-sectional plan view taken along the line II--II in FIG. 1;
FIG. 3 is a vertical cross-section showing a second embodiment of the present invention; and
FIG. 4 is a vertical cross-section showing a conventional apparatus.
DETAILED DESCRIPTION
Referring to FIGS. 1 and 2, the apparatus according to the present invention comprises a housing 1 which defines a drying chamber 2 therein. A rotary member 6 is rotatably provided in the chamber 2, and is fixedly coupled to a rotary shaft 20 which is connected in turn to a motor (not shown), thereby rotation of the rotary member 6 is carried out. An exhaust duct 5 is pneumatically connected to the lower side portion of the chamber 2, through which undesired objects, such as water or vapor and dirt from wafers to be processed, are expelled as shown by an arrow F by means of a suction pump (not shown) which is connected at the other end of the exhaust duct.
A couple of wafer cassette holders 11 adaptable to receive a wafer cassette 7 respectively therein are pivotably mounted at the opposite sides of the rotary member 6 by means of hinges 21. In respective wafer cassette 7 there are stored a plurality of wafers to be processed. On the top of the rotary member 6 there is provided a circular plate 13 so as to prevent undesired objects from entering into the inside of the rotary member. The circular plate 13 has a circular opening 14, as clearly shown in FIG. 2, to allow the introduction of clean air therethrough, and has a couple of notches at the positions corresponding to the cassette holders 11 to allow the holders to rise therethrough.
On the outer side wall of the housing 1, there is provided a lever 10 having a contact member 10a at the end thereof, the lever being movable in horizontal directions, by which the cassette holder 11 pivots as shown by an arrow B.
On the top of the housing 1 there is provided a circular lid member 3 which is openably mounted by hinges (not shown). The open-close operation of the lid member 3 is performed by a pneumatic cylinder (not shown). The lid member 3 has an opening to introduce clean air into the chamber 2 therethrough. Immediately beneath the opening of the lid member 3 an air filter 19 is provided to clean the air to be introduced.
A partial conical plate 8 extends downwardly to immediately above the rotary member. It is especially preferable that the lower end of the plate 8 comes near the upper margin of the rotary member 6, i.e., circular plate 13, as far as possible, so that undesired objects are prevented from entering into the inside of the rotary member through the space therebetween. As can be apparently understood, the partial conical plate 8 functions as a primary barrier against the undesired objects, and on the other hand the circular plate 13 functions as an auxiliary barrier.
A rinse conduit 9 is provided at the center of the rotary member 6, the conduit substantially vertically extending therein. At the peripheral surface of the conduit 9, fine holes are radially provided through which rinse solution is supplied to the wafers stored in the wafer cassette 7. If desired, the conduit 9 is available for use in supplying inert gas by means of an appropriate switching member (not shown).
In the upper peripheral portion within the chamber 2 there is provided an auxiliary chamber 17 for collecting the undesired objects therein, the auxiliary chamber 17 being pneumatically connected to the chamber 2 and on the other hand to an auxiliary duct 18 which in turn is connected to the exhaust duct 5.
In operation, a wafer cassette in which a plurality of wafers to be processed are stored is fed to a predetermined position just above the lid member 3. The lid member 3 is opened by a pneumatic cylinder (not shown), and simultaneously the lever 10 moves in the direction shown by an arrow A, the contact member 10a of the lever pushing the cassette holder 11 as the lever moves. Then the cassette holder 11 is raised upwardly as shown by an arrow B. At the position depicted by two-dashed lines the cassette holder 11 receives a wafer cassette 7 therein. After that, the lever 10 moves inversely, thereby the cassette holder returns back to the initial position thereof. Then the rotary member 6 is rotated 180 degrees. Then, the aforementioned operation is repeated, so that a wafer cassette 7 is loaded in the respective cassette holder 11. After that, the lid member 3 is closed, and rotation of the rotary member 6 is commenced.
Rinse solution is supplied through the fine holes of the conduit 9 to the wafers 7a for a predetermined period. Clean air is introduced through the opening of the lid member 3, hence through the air filter 19, into the chamber 2. The wafers stored in the cassettes 7 are thus rinsed, and used rinse solution and introduced air are forced outwardly from the rotary member. The used solution and introduced air may be substantially expelled through the exhaust duct 5. Remaining undesired objects, such as fine solution drops or vapor and dirt from the wafers, are collected in the auxiliary chamber 17 to be exhausted through the auxiliary duct 18, hence through the exhaust duct 5.
After rinse processing as mentioned above, the solution supply from the conduit 9 is stopped, while rotation of the rotary member 6 continues. The solution or water remaining on wafer surfaces is shaken off by the centrifugal force of the rotary member 6. Simultaneously, since clean dry air is introduced through the opening of the lid member 3 and is supplied to the wafers, the dry processing of the wafers is facilitated.
During the dry processing, undesired objects sprung from the rotary member 6 are substantially expelled through the exhaust duct 5, and are partially collected in the auxiliary chamber 17.
During the dry processing as well as the rinse processing, undesired objects may be apt to enter the inside of the rotary member 6. However, since the barrier plate 8 and the auxiliary barrier plate 13 are provided against the entrance of undesired objects, they are completely expelled to the auxiliary chamber 17.
Accordingly, the wafers stored in the cassettes 7 are cleanly rinsed and dried without any contamination and spoilage of the wafers.
FIG. 3 shows another embodiment of the present invention, wherein like reference numerals and letters designate like or corresponding parts of the embodiment shown in FIGS. 1 and 2.
In FIG. 3 the auxiliary chamber 17 has a tilt 16 facing to the conical barrier plate 8, and is separate from the lid member 3. The slit pneumatically communicates between the chamber 2 and the auxiliary chamber 17. The conduit 9 provided at the center of the rotary member 6 extends vertically up to the outside of the lid member 3, and is fixedly supported by means of a supporting member (not shown).
In the aforementioned embodiments, the auxiliary duct 18 is connected to the exhaust duct 5. However, it is apparent that the auxiliary duct may be directly connected to another suction pump (not shown).
Of course, the number of cassette holder may be increased, if desired.
In the illustrated embodiments, the barrier plate 8 is integral with lid member 3, but it may be mounted to the housing body.
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An apparatus for processing semiconductor substrates (i.e., wafers) or the like by rotation of the same. The apparatus includes: a housing which defines a processing chamber therein; and an exhaust duct connected to the lower side portion of the chamber. A rotary member is rotatably mounted in the chamber, on which a plurality of wafers to be processed are held. At the upper side portion within the chamber an auxiliary chamber is provided. Undesired objects, such as water remaining on the wafers and vapor and dirts sprung from the wafers, are effectively expelled from the chamber, through both the exhaust duct and the auxiliary chamber.
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CROSS-REFERENCE TO RELATED APPLICATION
This application is a divisional of application U.S. Ser. No. 09/079,815, filed May 15, 1998. U.S. Pat No. 6,186,471.
BACKGROUND OF THE INVENTION
The invention relates to actuators and zone valves for heating and cooling systems.
Zone valves are often utilized in hydronic heating and cooling systems. The zone valves isolate specific areas or “zones” of the system. Typically, each zone valve is controlled by a thermostat, which causes the valve to open and close to achieve desired temperature changes.
Conventional zone valves are typically actuated by either a heat motor or an electric motor. In valves with a heat motor as the actuator, an electrically heated element causes linear movement of an actuating element that, in turn, opens the valve. In valves with electric motors, the motor and associated gears move a valve member between closed and open positions (e.g., a rubber plunger moved away from a seat or a ball element moved through a 90 degree rotation).
Conventional motorized zone valve actuators employ a motor which is energized in one direction by a source of power, held in some predetermined position by a mechanical or electrical braking means, and then returned to its original position by a spring.
Giordani, U.S. Pat. Nos. 5,131,623 and 5,540,414, describe zone valves for hydronic heating or cooling systems in which a motor-driven actuator rotates a ball valve through about a 90° rotation, between closed and opened positions. The motor rotates the valve from its normal position, which may be either open or closed, to the opposite position, e.g., if the valve is normally closed, from the closed to the open position. When the motor is de-energized, the valve is returned to its normal position by a spring so configured that it provides sufficient restoring torque to overcome the frictional torque of the ball valve.
Carson, U.S. Pat. No. 3,974,427, discloses a motor control apparatus having an electric motor which is driven in one direction by an alternating current power source and in the opposite direction by a spring. Holding or braking of the motor is accomplished by applying a source of direct current power to magnetize the motor and hold it in a predetermined position after the alternating current power source is removed. This holding or braking action is removed by taking away the direct current power source and momentarily applying an alternating current power source to the motor, thereby de-magnetizing or degaussing the motor so that it is free to return to its initial condition under the power of the spring.
Fukamachi, U.S. Pat. No. 4,621,789, discloses a valve mechanism in which the valve is prevented by a physical stopper from moving any further after it has moved to an open or closed state.
Botting, et al, U.S. Pat. No. 5,085,401, discloses a valve actuator in which the motor makes an electrical contact after rotating a predetermined distance, causing deenergization of the motor.
Fukamachi, U.S. Pat. No. 4,754,949, discloses a valve actuator in which the rotation of the valve by a predetermined amount causes electrical contacts to be turned off, stopping the rotation of the actuator motor.
Some motorized valve actuator systems employ a fail safe energy system to provide power to the actuator motor in the event that the main power source is lost. Strauss, U.S. Pat. No. 5,278,454, discloses an emergency, fail safe capacitive energy source and circuit which is used to power an air damper actuator or a valve actuator. A sensor detects loss of power to the valve actuator circuit or motor, activating a switch which connects a bank of capacitors to the motor, with the appropriate polarity to drive the actuator back to its fail safe position. No provision is made for interrupting the connection between the capacitors and the motor when the fail safe position is reached, and thus the motor appears to work against a mechanical stop defining the fail safe position.
SUMMARY OF THE INVENTION
The invention features an actuator in which a sensor detects when the valve has reached a desired position, and controls a switch that shuts off the motor driving the valve. The invention makes it unnecessary to rely on a mechanical stop or a return spring to put the valve in a desired position. For example, a valve can be moved from open to closed and from closed to open, without relying on a mechanical stop or return spring. And switching a valve from normally-open to normally-closed can be done simply by throwing a single switch.
In one aspect, the invention features an actuator for actuating a valve in a hydronic system, wherein the valve has a first position in which fluid flow may occur along one path and a second position in which fluid flow is either blocked or may flow along another path. The actuator includes: a motor coupled to the valve, wherein rotation of the motor changes the position of the valve from one of the first and second positions to the other of the positions; a switch controlling the delivery of electrical power to the motor, the switch having a closed position in which electrical power is delivered to the motor and an open position in which power is not delivered; a sensor configured to detect the arrival of the valve at the first and second positions; and circuitry connected to the sensor and to the switch, the circuitry being configured to respond to the detection by the sensor of the arrival of the valve at one of the first and second positions by opening the switch to stop delivery of power to the motor.
Preferred implementations of the invention may include one or more of the following features: The sensor may be configured so that the output of the sensor changes state upon the arrival of the valve at a desired position. The sensor may have two states, and a change of state in its output occurs at approximately the moment when the valve, having begun to move from one of the first and second positions, reaches the other of the positions. The motor may rotate the valve in a single direction. An electrical power storage element (e.g., a capacitor) can be included in the actuator for providing power for driving the motor, sensor, and circuitry (e.g., when power to the actuator is lost). The circuitry for controlling the actuator can be provided by an integrated circuit chip. The valve may be a ball valve. The sensor may be an optical sensor. The actuator may have projections on a member that rotates with rotation of the valve and the projections may cause the sensor to become blocked and unblocked, and arrival of the valve at a position corresponds to blockage of the sensor by a projection either ceasing or beginning. The actuator may include a clutch for manually rotating the valve, and the position of the clutch may provide an indication of the angular position of the valve. The actuator may include a worm gear drive between the motor and the valve. A default-position selection switch may be included to enable the actuator and valve to be transformed from a normally-open valve to a normally-closed valve by movement of an electrical switch.
In a second aspect, the invention feature a zone valve for use in a hydronic system, in which the valve includes a ball element; a valve casing enclosing a ball element; a valve seat in contact with the ball element and the valve casing, the valve seat having a notch to receive an O-ring; an O-ring installed in the notch; a metallic, springy washer positioned in a compressed state within the valve casing in such a configuration as to provide an approximately constant force on the valve seat; and wherein the notch is shaped so that the axial force causes the O-ring installed in the notch to be compressed to improve a seal between the valve seat and an internal bore of the valve casing.
In a third aspect, the invention features operating a hydronic valve actuator by, prior to initiating movement of the valve, determining the charge on a capacitive power source and determining the energy required to complete the valve movement prescribed, and then deciding to initiate movement only if the charge on the capacitive power source is sufficient to provide the energy required to complete the movement.
In a fourth aspect, the invention features a hydronic valve actuator including a motor for driving the valve, wherein rotation of the motor changes the position of the valve from one of the first and second positions to the other of the positions; a gear assembly coupling the motor to the valve, wherein the gear assembly includes a worm gear; and a knob shaped to be turned manually either by grasping or by use of a tool; a clutch assembly connecting the knob to the valve stem and to the gear assembly, wherein the clutch assembly can be moved between engaged and disengaged modes, wherein in the engaged mode the gear assembly and worm gear are engaged with the valve stem so that the motor can turn the valve, and in the disengaged mode the gear assembly and worm gear are disengaged from the valve stem so that the valve can be turned using the knob.
Preferred implantations of this aspect of the invention may include one or more of the following features: The clutch assembly may be disengaged by pushing the knob axially. The clutch assembly may include teeth on two rotating members that are separated by axial motion of the knob to disengage the clutch. The knob may have a marking indicating the position of the valve.
Other features of the invention will be apparent from the following description of preferred embodiments, including the drawings, and from the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross-sectional view of a valve and actuator according to the invention.
FIG. 2 is an isometric view of the interior of the actuator.
FIG. 3 is an isometric, exploded view of components of the clutch mechanism of the actuator.
FIGS. 4A-4D are diagrammatic views of the optical sensor and drive member of the actuator in four different positions.
FIG. 5 is a schematic of the electronics of the actuator.
FIGS. 6-13 are flow charts of the processes followed by the microprocessor in controlling the actuator.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows a preferred zone valve 10 . Ball valve 12 is driven by actuator 14 . The actuator is coupled to the valve body 26 (bronze forging) by a rotate-to-lock fastening arrangement 23 . Flat-sided stem 16 extends from ball element 18 into a matching opening 19 in the actuator. The actuator is electrically operated, and has wires for coupling it to conventional power and control circuitry.
Fluid flows through the ball valve in a conventional manner. When the ball is in the open position, fluid flows through the ball element 18 from port 37 a to port 37 b . The valve is bidirectional, and thus either of ports 37 a , 37 b can be an inlet or an outlet.
Ball element 18 (brass) seals against seats 20 a , 20 b (Teflon), which are, in turn, sealed to the internal bore 25 of the valve forging by O-rings 22 a , 22 b , which sit in O-ring notches 21 a , 21 b . A wavy washer 30 (stainless steel) provides an axial force on the seats 20 a , 20 b (the curvature of the washer is exaggerated in the drawing). Notches 21 a , 21 b have a surface inclined with respect to the axial direction, as shown in FIG. 1, so that the axial force compresses the O-ring, causing them to press outwardly against the bore of the valve casing, to effect a seal between the valve seats and the bore. The wavy washer presses against backing ring 24 (stainless steel), which presses against O-rings 22 a . By making the wavy washer out of a springy metallic material (e.g., stainless steel), it retains its resiliency over time. As O-rings 22 a , 22 b compress over time, the wavy washer expands while maintaining adequate axial force. Over the life of the valve, the wavy washer will compensate for the tendency of the Teflon valve seats to cold flow and/or wear; the washer will expand slightly, to maintain the seats in contact with the ball.
Referring to FIG. 2, a motor 40 turns a pinion 42 , which in turn drives a cluster gear 44 , consisting of a large and small spur gear molded as one plastic part. Cluster gear 44 drives a second cluster gear 45 , consisting of a small spur gear 47 and a worm gear 34 also molded as one plastic part. The worm gear engages drive gear 31 , which, in turn, rotates drive member 47 , which, in turn, rotates valve stem 16 . The entire gear train (pinion gear 42 through drive gear 31 ) provides a 960:1 increase in torque. The worm gear 34 and drive gear 31 provide an 80:1 increase.
Referring to FIG. 3, the ball valve 12 may be manually opened and closed by depressing and turning a knob 70 (FIG. 3) exposed above the top cover (not shown) of the actuator. The knob is connected to stem 16 of the ball valve via drive member 47 , and can be manually disengaged from drive gear 31 using a clutch mechanism 38 . Normally, valve clutch teeth 48 on the drive member interlock with valve teeth 50 on the drive gear. A compression spring 32 (FIG. 1) wraps around shaft 49 , and provides an upward force on drive member 47 to keep the teeth engaged. Manual movement of the valve is not possible with the teeth engaged, as such movement would require that drive gear 31 turn worm gear 34 in reverse (the 80:1 torque ratio of the worm and drive gears prevents that from happening). To manually rotate the valve, the valve clutch teeth 48 are disengaged from the valve teeth 50 by pressing downward on knob 70 (FIG. 3) and rotating drive member 47 . Because the drive member is directly connected to the valve stem 16 , rotation of knob 70 results in rotation of the ball valve. Once the clutch is disengaged, the valve may be rotated in either direction. After the valve has been manually rotated to a desired position, pressure is removed from the knob, spring 32 causes the clutch teeth to reengage. A valve position indicator 54 is molded into knob 70 , to provide a visual indication to the valve operator of the current position of the valve. A notch 56 is provided in the knob to permit a screwdriver, or other thin rigid object, to be used to turn the valve.
The electronic circuitry controlling operation of the actuator depends on an optical sensor U 2 (FIGS. 3 and 4 A- 4 D) to determine the position of the valve. The sensor is positioned so its light path is alternately blocked and unblocked as drive member 47 is turned. Projections 72 , 74 extending from the drive member pass through the optical path of the sensor.
FIGS. 4A-4D illustrate operation of the sensor. Projections 72 , 74 are positioned on drive member 47 so that the sensor is blocked in two quadrants of rotation of the drive member. Each of projections 72 , 74 blocks the optical sensor over 90° of travel, leaving 90° between them in which the sensor is not blocked. In operation, the circuitry controlling motor 40 will turn the motor on and keep it on until a change of state occurs at the optical sensor. E.g., if movement of the valve were to begin with the drive member in the position shown in FIG. 4A, in which the optical sensor is blocked by projection 72 , movement would continue for approximately 90 degrees of travel, until the drive member rotated to the position shown in FIG. 4B, wherein projection 72 has just moved out of the path of the optical sensor. (A natural lag between the moment that the sensor detects a change in state and actual cessation of movement assures that the actuator stops a small angular displacement beyond the position at which the optical sensor became unblocked; this assures that vibration will not cause the sensor to become blocked again and restart.) This 90 degrees of movement would have either opened or closed the ball valve. If further movement of the ball valve were called for (e.g., if the valve were now open, and the circuitry called for the actuator to close the valve), the motor would be turned on and the valve would continue to rotate for approximately another 90 degrees of travel to the position shown in FIG. 4C, at which point the optical path is again blocked, this time by projection 74 .
FIG. 5 is a schematic of the electronic circuitry of the actuator. At the heart of the circuitry is a microprocessor U 1 , which has programmable pins GP 0 , GP 1 , GP 2 , GP 3 , GP 4 , and GP 5 , a power supply pin Vdd, and a ground pin Vss. Power (24V AC) is supplied to the circuitry through two-pin connector CONN 1 . Typically, a 24V AC transformer is connected to CONN 1 through a thermostat. When the thermostat turns on, 24V AC flows through CONN 1 and into the power supply circuitry (diode D 1 , resistors R 1 and R 2 , and transistor Q 1 ), which sets supply voltage Vcc.
A capacitor C 1 with a capacitance of 3.3 is connected between Vcc and ground. During normal operation, the capacitor C 1 charges to 2.5V to provide power to the motor 40 , as described below. A switch SW 1 is used to configure the zone valve 10 to be either normally open or normally closed. The position of switch SW 1 can be changed by an operator by means of a slide knob 58 accessible on the exterior of the actuator assembly 14 (FIG. 2 ).
Power to optical sensor U 2 is provided at pin GP 0 of the microprocessor U 1 . When the light path to the optical sensor U 2 is blocked, pin 4 of the sensor outputs a logical LO. When the light path is not blocked, pin 4 outputs a logical HI.
A two-pin motor connector J 1 provides power to motor 40 . Supply voltage Vcc is delivered at one pin. The other pin is connected to gating transistor Q 2 , which is in turn controlled by the microprocessor. When microprocessor pin GP 4 is HI, transistor Q 2 turns on, supplying power to the motor 40 . Otherwise, power to motor 40 is cut off.
The circuitry shown in FIG. 5 may be powered by AC power supplied at connector CONN 1 ranging from approximately 8V to approximately 40V. Diode D 1 converts the supplied power from AC to DC (the same power supply would also function if supplied with DC power). When transistor Q 1 is on, capacitor C 1 is charged by the power supplied at connector CONN 1 minus the voltage drop across the circuit consisting of diode D 1 , resistor R 1 , and transistor Q 1 . Capacitor C 1 will charge when at least 2.5V is present at Vcc. Taking into account the voltage drop across D 1 , R 1 , and Q 1 , and the power necessary to run the microprocessor U 1 and the motor 40 , the circuitry shown in FIG. 5 can operate with a minimum of approximately 8V AC. As the supplied voltage is increased, capacitor C 1 will continue to charge and sufficient power will be supplied to the microprocessor U 1 and to the motor 40 .
FIG. 6 is a flow chart of the process followed by the microprocessor U 1 in controlling the motor 40 . When power to the microprocessor U 1 is turned on (step 310 ), state variables and other parameters are initialized (step 315 ). Next, the main control loop is entered. The loop begins by checking the voltage at the microprocessor's Vdd input, and determining whether there is sufficient power to power the motor 40 (step 320 ). The output of the optical sensor U 2 is then checked to determine whether the zone valve 10 is passing in front of the optical sensor (step 325 ). The microprocessor U 1 then obtains the current state of switch SW 1 (step 330 ), and detects whether an AC signal is present at pin GP 5 (step 335 ). Next, the microprocessor U 1 decides whether or not to continue charging capacitor C 1 (step 340 ).
In steps 345 - 365 , the microprocessor U 1 decides whether the motor 40 should be turned on or off. If the zone valve 10 is normally closed (decision step 345 ), then the Result register of the microprocessor U 1 is assigned the value OPTO XOR AC (step 355 ). If the zone valve 10 is normally open, (as indicated by switch SW 1 being in position 1 ) (decision step 345 ), then the OPTO flag is toggled (step 350 ) before assigning to the Result register the value OPTO XOR AC (step 355 ). A Result register value of TRUE indicates that, if there is sufficient power, the motor 40 should be turned on. A Result register value of FALSE indicates that the motor 40 should be turned off.
The process 300 shown in FIG. 6 is now described in more detail.
Referring to FIG. 7, initialization (step 315 ) proceeds as follows. First, the optical sensor U 2 is turned off by de-asserting pin GP 0 (step 410 ), in order to conserve power. Next, a flag V_READY, which is used to indicate whether the capacitor C 1 has been fully charged, is initialized to FALSE (step 415 ). A variable AC_PREVIOUS, used by the method of FIG. 11 and described in more detail below, is initialized to LO (step 417 ). Next, the motor 40 is turned off by de-asserting pin GP 4 in order to conserve power (step 420 ). Next, if pin GP 5 is HI (decision step 425 ), indicating the possible presence of an AC signal (or DC signal in the event that the power supplied to the actuator is DC instead of AC), the microprocessor U 1 delays for one tenth of a second, and then checks pin GP 5 again to verify the presence of an AC (or DC) signal (step 440 ). If pin GP 5 is not HI during both steps 425 and 440 , then the presence of an AC signal has not been verified, and the microprocessor U 1 goes into sleep mode (step 430 ). Once in sleep mode, the microprocessor U 1 will wake up again in approximately one second and begin again at step 315 . If pin GP 5 is HI at steps 425 and 440 , then control proceeds to FIG. 9 (step 445 ).
Note that if an AC signal is present and the microprocessor U 1 is either turned off or in sleep mode, then pin GP 2 will act as an open circuit (exhibit high impedance), in which case transistor Q 1 will turn on, allowing the AC signal to charge capacitor C 1 .
Referring to FIG. 8, the microprocessor U 1 estimates the voltage at pin Vdd by as follows. First, a local variable COUNT is initialized with a value of 25 , and a local variable VCNT is initialized with a value of zero (step 510 ). Next, the microprocessor U 1 determines whether pin GP 1 is HI (decision step 515 ). If GP 1 is HI, then VCNT is incremented (step 520 ). This process repeats 25 times (steps 515 - 530 ). Whether pin GP 1 is HI is an indicator of the voltage at pin Vdd because pins GP 1 and Vdd are internally connected by a single 25 kΩ resistor (not shown). The microprocessor U 1 estimates the voltage Vdd as Voltage=2.3+0.1* VCNT (step 535 ). If Voltage>2.5 (decision step 540 ), indicating that the capacitor C 1 has been fully charged, then a flag V_READY is set to TRUE (step 545 ). Otherwise, the V_READY flag is set to FALSE (step 550 ).
FIG. 9 shows a method used by the microprocessor U 1 to determine whether the optical sensor U 2 is blocked. The result of the method of FIG. 9 is to set the OPTO flag to TRUE if the optical sensor U 2 is not blocked, and to set the OPTO flag to FALSE if the sensor is blocked. First, power to the optical sensor U 2 is turned on by asserting pin GP 0 (step 610 ). Next, an arbitrary 8-bit binary code is transmitted through pin GP 0 , one bit at a time (step 615 ). As the microprocessor U 1 transmits the code, the microprocessor U 1 monitors the input at pin GP 1 . If the value of the bit received at pin GP 1 is the same as the value of the bit transmitted at pin GP 0 , then the optical sensor is not blocked. If all of the bits in the transmitted code are correctly received at pin GP 1 (decision step 620 ), then the OPTO flag is assigned a value of TRUE (step 630 ). Otherwise, the OPTO flag is assigned a value of FALSE (Step 625 ). In either case, the power to the optical sensor U 2 is then turned off by de-asserting pin GP 0 (step 635 ). Eight bits, rather than a single bit, are transmitted and tested in order to take into account manufacturing imperfections in the zone valve 10 which might cause spurious readings of the optical sensor when an edge of the drive member 47 is in front of the sensor. Requiring that eight consecutive readings of the optical sensor output all match the expected readings ensures that the zone valve 10 has completed a state transition.
Referring to FIG. 10, the NORMALLY_OPEN flag, which indicates whether the zone valve 10 is normally open or normally closed, is set as follows. If pin GP 3 is HI (decision step 710 ), then the NORMALLY_OPEN flag is assigned a value of TRUE (step 715 ). Otherwise, the NORMALLY_OPEN flag is assigned a value of FALSE (step 720 ).
Referring to FIG. 11, a flag AC is assigned a value of TRUE when an AC signal is detected at pin GP 5 , and is assigned a value of FALSE when no AC signal is detected for a period of time. In addition, a flag AC_TRANSITION is assigned a value of TRUE when the flag AC changes value, and is assigned a value of FALSE otherwise.
More specifically, the values of AC and AC_TRANSITION are assigned as follows. First, the microprocessor U 1 determines whether pin GP 5 is HI (decision step 810 ). If it is not, then the microprocessor U 1 initializes a variable COUNT to a value of 150 and assigns the value TRUE to the flag AC (step 815 ). Then, if AC is not equal to AC_PREVIOUS (decision step 820 ), then the value of AC_TRANSITION is set to TRUE (step 835 ). Otherwise, the value of AC_TRANSITION is set to FALSE (step 837 ). The value of AC_PREVIOUS is then assigned the value of AC (step 840 ).
If pin GP 5 is HI (decision step 810 ), then COUNT is decremented (step 825 ). If COUNT=0 (decision step 830 ), then AC is set to FALSE (step 845 ).
Referring to FIG. 12, the microprocessor U 1 decides whether to continue charging capacitor C 1 as follows. If V_READY is FALSE (see FIG. 8) (decision step 910 ), then capacitor C 1 is charged by putting pin GP 2 into input mode, causing pin GP 2 to act like an open circuit (step 915 ). If V_READY is TRUE (decision step 910 ), then the microprocessor U 1 stops charging capacitor C 1 by putting pin GP 2 into output mode and asserting LO, causing pin GP 2 to act like a short circuit (step 920 ). This turns off transistor Q 1 , which prevents capacitor C 1 from charging.
After the method of FIG. 12 has completed, the microprocessor decides whether the motor should be turned on or off. If the switch SW 1 is in position 1 , indicating that the zone valve 10 is normally open (decision step 345 ), then the OPTO flag is toggled (step 350 ). Then, the Result register is assigned the value OPTO XOR AC. A Result value of TRUE indicates that the motor 40 should be turned on, if there is sufficient power. A Result value of FALSE indicates that the motor 40 should be turned off. The expression OPTO XOR AC results in the appropriate values for the Result register as follows.
TABLE 1
Result
Result
(Normally
(Normally
SENSOR
OPTO
AC
Open)
Closed)
BLOCKED
FALSE
FALSE
TRUE
FALSE
BLOCKED
FALSE
TRUE
FALSE
TRUE
UNBLOCKED
TRUE
FALSE
FALSE
TRUE
UNBLOCKED
TRUE
TRUE
TRUE
FALSE
Referring to Table 1, consider, for example, the case in which the zone valve 10 is normally closed (i.e., switch SW 1 is in position 2 ). In this case, if OPTO is FALSE (i.e., the optical sensor is blocked, indicating that the zone valve 10 is closed) and AC is FALSE (indicating that the thermostat is not requesting that the zone valve 10 change its state), then the zone valve 10 is in the correct position. Therefore, the value of Result is FALSE, indicating that the motor should be turned off. Consider next, for example, the case in which the zone valve 10 is normally open (i.e., switch SW 1 is in position 1 ). In this case, if OPTO is FALSE (i.e., the optical sensor is blocked, indicating that the zone valve 10 is closed) and AC is FALSE (indicating that the thermostat is not requesting that the zone valve 10 change its state), then the zone valve 10 should return to its default position of open. Therefore, the value of Result is TRUE, indicating that the motor 40 should be turned on. The values in the remaining cells in Table 1 can be verified similarly.
Once the value of Result has been calculated, the microprocessor U 1 decides whether to actually provide power to the motor 40 as shown in FIG. 13 . If V_READY is TRUE, then pin GP 4 is asserted, turning the motor 40 on (step 1015 ). If V_READY is FALSE, then the motor 40 is not turned on. This ensures that the motor 40 is not turned on unless there is sufficient power.
Other embodiments of the invention are within the scope of the following claims. For example, the invention may be used to provide other types of valves, e.g., a mixing valve or a two-way valve.
In the case of a mixing valve, a different ball element, with a central aperture communicating with port 37 c (FIG. 1) at the base of the valve body, replaces the ball element shown in FIG. 1 . Ports 37 a , 37 b become inlets (e.g., hot and cold water) and port 37 c is the outlet. The left-to-right aperture in the ball element, which is straight in the embodiment of FIG. 1, becomes curved so that rotation of the ball element causes a change in the proportions of fluid flowing through the valve from the two ports. By using a noncircular cross motion for the aperture (e.g., tear drop), a linear relationship can be achieved between ball rotation and flow. Projections 72 , 74 are also configured differently so that the output of the optical sensor changes state after the ball element has turned sufficiently to complete close off one of the ports. E.g., one of the projections might block the sensor to indicate that port 37 a was shutoff, and the other of the projections might do the same for port 37 b . In operation, movements of the mixing valve are controlled by activating motor 40 for short durations to make small adjustments to the position of the ball element. Polarity of the power is reversed to change the direction of rotation. During these movements the optical sensor does not provide information; it is only when the ball element has reached a point at which one or the other of the ports is closed off that the sensor functions. In effect, it replaces the mechanical stop that would be found in a conventional mixing valve.
For a two-way valve, the right-to-left aperture in the ball element extends from the center of the ball in only one direction, so that by rotating the valve 180 degrees, the central port 37 c can be connected to one or the other of ports 37 a , 37 b . The same configuration of projections 72 , 74 can be used, or alternatively, a single projection extending 180 degrees could be substituted.
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A zone valve for use in a hydronic system, the valve including a ball element through which liquid flows in an axial direction, a valve casing enclosing a ball element, a valve seat in contact with the ball element and the valve casing, the valve seat having a notch to receive an O-ring, an O-ring installed in the notch, and wherein the notch has a surface inclined with respect to the axial direction so that an axial force on the valve seat causes the O-ring installed in the notch to be compressed to improve a seal between the valve seat and an internal bore of the valve casing.
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PRIOR FILINGS
[0001] This application is a continuation-in-part and claims the benefit of co-pending U.S. application Ser. No. 09/667,182, filed Sep. 21, 2000 by inventor Romeo Prasad and entitled “System for Preventing Crime in High Traffic Buildings”, which is hereby expressly incorporated by reference into this application.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention is directed to providing automatic protection for highly trafficked buildings such as schools, stores, banks, warehouses, storage areas or other buildings from entry of weapons or of persons possessing weapons, or from illegal removal of merchandise. In particular, it deals with a low voltage system of electronic and mechanical equipment to robotically stop entry/exit and detain persons attempting to commit a crime in a protected area/building.
[0004] 2. Prior Art Statement
[0005] There are many security systems to protect persons and buildings from criminals in the art. Many are called anti-crime or anti-robbery security systems. Generally they detect weapons on potential terrorists or criminals and alert some security force as to the entry of such person or persons. Often alarms are set off to deter action, but these give the perpetrator an opportunity to escape or capture hostages to trade for safe passage out.
[0006] Newer designs, like the silent alarms in banks, attempt to detect and alert personnel away from the entry/detection site without alerting the perpetrator. In many cases to detain a perpetrator, guards or other personnel have to activate precautionary measures to stop the criminal from departing but often at their own or bystanders' risk. Such systems are especially not optimal nor desirable for protecting school buildings or other public buildings where a general unsophisticated public may gather.
[0007] An alternative approach using a computer controlled double door enclosure and metal detecting sensors is described in U.S. Pat. No. 5,552,766 by Lee and Lee. Their anti-crime security system involves having the two doors enclose the area between the two doors. If the passageway and doors are small enough to restrict ingress and egress to one person at a time then problems with passing high traffic through the entry will be inherent to the system. Also the doors will both have to open out from the enclosure in order to permit the capture of a potential criminal within the enclosure. The latter also serves to restrict flow through the entry/exit. In a convenience store with its rather limited customer access, these problems can be tolerated. In a clothing store or a school or bank where often large numbers of people must pass through an entry or exit, these restrictions are not acceptable. If the restrictions are ameliorated than the security would be more easily compromised.
[0008] In another scheme when the area to be protected/secured is a known secure area, as in a military building, a nuclear power plant, a prison, or a weapon research center, there are systems which provide for selective access to secure regions from non-secure regions as in U.S. Pat. No. 4,586,441. Persons attempting to enter the secure area expect delay and some restriction on direct entry. For schools, banks and the like, i.e. places where it is not desirable nor completely feasible to stop and check every entrant all the time, even semi-automatic systems as described in U.S. Pat. No. 4,586,441 are not a solution. They would create almost a many problems as they would solve. For example, no one wants schools and banks and the like to feel like prisons. And yet in these often tumultuous times, it would be good to have ways to restrict the ingress and egress of persons trying to disrupt or threaten public places such as schools, etc.
[0009] An anti-robbery an anti-hostage equipment provided with a one-way rotating door for banks and the like was described by Pretini is U.S. Pat. No. 4,063,519. This particular systems of this patent involve multiple rotating doors and isolation passageways between them wherein detectors can probe persons attempting to enter the final protected area. The system is elaborate and its practicality even for banks is questioned since this patent is over 23 years old and, even though it no longer restrains use of its teachings, there is little or no evidence that such systems have ever been in use commercially.
[0010] In U.S. Pat. No. 4,341,165 (Calandritti et al.), it does teach of using a revolving door as a security system, with four zones and the ability to capture/detain a person who has tripped the weapon detectors. It also, however, teaches use of multiple electric motors to activate the doors, critically to close the sliding panel into the exit region when a weapon carrying intruder is detected, and to operate the detection system as well. This limits the operation and placement of the security system. It also contributes making the system costly initially and also in operation and use. In '165, the underlying structure is powered by multiple motors which are used in conjunction with the detector in an elaborate system powered by a power grid as used in commercial electrical systems. It is the stopping of the motors driving the door panels which is crucial to detaining an intruder.
[0011] The present invention provides a low voltage powered, substantially automatic, detection and detention system to prevent crime in highly trafficked buildings or other sites, including where or when normal power is not readily or conveniently available.
SUMMARY AND OBJECTIVES OF THE INVENTION
[0012] It is an object of the present invention to provide a security system to prevent crimes within high traffic buildings and sites without the need for standard electrical power.
[0013] It is another object of the present invention to provide a security system to not only detect but also capture persons attempting to bring weapons into public buildings and sites, independent of normal electrical power.
[0014] It is an object of the present invention, in particular, to provide a substantially automatic compact security system for use in entries to banks or schools, including playing fields and the like.
[0015] It is a further object of the present invention to provide a space effective system to detect weapons on entering persons and to detain them before entry into the protected facility, without requiring attachment to power grids or high voltage sources.
[0016] It is yet another object of the present invention to provide an exit security system for controlled areas to aid in capture of persons attempting to flee from the area with a controlled/protected item or piece of merchandise.
[0017] It is also an object of the present invention to provide an exit security system for controlled areas to aid in capture of persons fleeing from a manually operated detection system, even when building power may be cut.
[0018] It is a still further object of the present invention to provide secured entry system which provides for substantially normal access to persons needing to use a public building, while detecting and detaining those trying to bring weapons into the facility or other public site, such as a stadium, playing field, etc.
[0019] Briefly stated the present invention provides an essentially automatic, robotic-like system to aid in preventing crime in high trafficked buildings and other public sites, using only low voltage power. In various modes it can protect public buildings such as schools, stadiums, open air markets, banks, office buildings from entrance of persons carrying weapons or separately trying to pass weapons into a protected area, even in the event of general power loss. Here the invention provides a well designed, compact solution to weapons detection and the detainment of persons attempting to disrupt, destroy or harm citizens in public buildings such as schools, banks, etc. with a minimum of restriction of access by persons regularly using the facilities. In other variations, it can be used to prevent unauthorized removal of costly or dangerous items from protected buildings or areas. Here the invention similarly provides a substantially automatic method of detection and detection of persons attempting to illegally remove items either without paying or that are not for sale in a store setting.
[0020] The above, and other objects, features and advantages of the present invention will become apparent from the following description read in conjunction with the accompanying drawing.
BRIEF DESCRIPTION OF FIGURES
[0021] [0021]FIG. 1 presents a schematic of the present invention wherein wire numbers are identified by their device and terminal numbers, e.g. for device 3 , wires 3 . 1 ., 3 . 2 and 3 . 3 . Crossing wires connect only where boxes are indicated.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0022] The key features of the present invention are a counterclockwise rotating door which permits access in one direction only and which may be manually operated always or in emergency conditions, two personnel detecting sensors, at least two other detectors, a low voltage power source and low voltage electronics, an electronic design to substantially automatically detect and detain persons attempting to enter a protected facility with a weapon or leave with a protected item, and where the entire security system is essentially contained within the space employed by the entry and or exit doorway. To obtain full protection from the system both entry and exit employ the one directional units. The basic system is hardwired for a specific site and use as described, for example, in the specific examples presented below. Where desired, a manually operating doorway systems maybe employed in conjunction with the present invention. Full computer control and capability to alter configurations by programming changes is envisioned as being within the scope of this disclosure. With an independent low voltage source the present system can maintain security even when in the midst of power failure to the surrounding and protected areas.
[0023] For security and safety reasons low voltage is used to power the electronics and the sensitivity of the weapons detector can be set or varied by authorized personnel. The digital key pad 10 , switch 7 and the key pad of telephone transmitter 11 , depicted in FIG. 1, can be attached onto a wall of the door unit within the protected area. This would permit manual activation from within the protected area. Alternatively, activation and position of these devices could be from some area remote to the door units.
[0024] Generally, each one way door unit is about 5-6 feet in maximum dimension. A double unit, providing an entry and an exit, would thus take up an area of about 6 feet deep by about 10 feet wide.
[0025] In the lower right hand corner of FIG. 1, the base of the rotating door assembly is presented with four identified zones, B, C, A, and D reading in a counterclockwise direction from the bottom. Zone B is the enter zone; a person can enter in this area only. Zone A is the exit zone; a person can exit in this area only. Zone C is the transfer and apprehension zone; a person can be apprehended, or a protected item detained in this area. Zone D is the dead zone; any time a person tries to enter this zone they are apprehended or alternatively hindered from entry. Switches 19 and 20 basically function as personnel detectors, which are closed when a person's weight is applied above them. They can also be set up to register movement of a door panel across either of them after another detector senses the presence of a protected item entering the zone, even if no one enters with the protected item.
[0026] The area in the upper left hand corner, contained within the lines bearing inward pointing arrows, represents the corresponding top view of the area above the rotating door assembly. Device 9 sits on an adjustable bracket essentially above areas D, E and C depicted in the base section of the figure. The position of device 9 can be adjusted to permit monitoring of area C or of area D. Devices 3 and 5 lie essentially above the center of zones D and C respectively. Detector 26 is positioned above the entry to zone C. Flywheel 6 is shown to have teeth oriented for one directional rotation when flywheel lever 8 is engaged. If flywheel level 8 is disengaged, as might be the case in a fire emergency, the revolving door could be allowed to freely rotate permitting exit from through an entry door.
[0027] Where the entrance and exit are positioned at the ‘front’ and ‘rear’ of a protected area the orientation of the two follow as shown in FIG. 1. At the entrance the entry is from zone B outside the protected area into zone A within the protected area, while for the exit zone B is within the protected area and the exit zone A is outside the protected area. Where the entrance and exit are positioned essentially side by side, the exit unit will be rotated by 180 degrees so that the two dead zones, D entrance and D exit are adjacent to each other. In either case each unit operates essentially the same with the entrance unit not permitting exit through it and the exit unit not permitting entry or re-entry through it.
[0028] By running all the detection, apprehension and detention components on low voltage, the security system can be used independent of exterior power permitting use in remote or temporary sites without power access, or in cases where the electrical power has been compromised or fails.
[0029] The following detailed descriptions help exemplify the invention in conjunction with FIG. 1 but do not represent all the possible variations that might be used within the scope of the scope of the invention.
EXAMPLE 1
Person Entering a School or Bank With a Weapon
[0030] As a person reaches area E when device 9 is main RF detector, 9 detects a weapon on the person and sends an electronic signal from point 9 . 3 through normally closed switch 7 to trigger relay 14 at point 14 . 1 . Next normally open relay 14 closes and reopens causing current flow from point 14 . 2 to latching relay 15 at point 15 . 1 . Latching switch 15 is latched continuously and current flows from point 15 . 3 to point 20 . 1 of normally open apprehension switch 20 . As the person enters zone C switch 20 is closed(activated) and current flows from point 20 . 2 to latching relay 16 at point 16 . 1 .
[0031] Latching relay 16 is latched continuously and then current flows from point 16 . 3 to normally open flywheel magnetic switch 2 as a door panel 17 rotates to timing apprehension position shown by the lower right hand static structure denoted as 24 . Normally open magnetic switch 2 activates(closes) and current flows from point 2 . 2 to latching relay 18 at point 18 . 1 .
[0032] Latching relay 18 is continuously latched and current flows from point 18 . 3 to magnetic lock 5 at point 5 . 1 , to time delay switch 23 at point 23 . 3 and to telephone transmitter 11 at point 11 . 3 . Magnetic lock 5 locks flywheel 6 by inserting its plunger into cylinder 25 preventing further rotation of the door. The person is trapped within zone C. Telephone transmitter 11 calls 911 or a predetermined internal security number. Siren 12 sounds for 5 minutes or some other pre-selected time period.
[0033] The detained person can be released when the proper 4 digit code is entered into key pad 10 . Key pad point 10 . 5 , which normally open, is closed and current flows to reset relay 13 at point 13 . 1 . Normally closed relay 13 opens and recluses disturbing the current flow to latching relays 15 , 16 , and 18 . Magnetic lock 5 is unlocked by the withdrawal of its plunger from cylinder 25 and the door may now rotate to allow the person to exit in zone A.
[0034] Note that all aspects of the present invention can preferably be powered by a self-contained low voltage battery source similar to an automotive style 12 volt battery. The panels of the door unit can be operated manually, if the site to be protected can not be conveniently electrified, connected to a power grid. Also by not relying on the power used by the door unit in operation, the security system can be used even if general power has been lost or purposely shut off. In general for use in high traffic areas, entry/exits would need to have a release of powered restraint to permit orderly access during an emergency. The present invention would not have to release a captured person nor be made inactive without specific, conscious action by operators/monitors, simply because a general power loss occurred.
ALTERNATIVE EXAMPLE 1
Person Entering With a Weapon
[0035] In the case where device 9 is not an RF detector, as a person passes from area E through zone B into zone C, RF detector 26 detects a weapon on the person and sends an electronic signal from point 26 . 3 to latching relay 16 at point 16 . 1 . Also as the person enters zone C switch 20 is closed(activated) and current flows from point 20 . 2 to latching relay 16 at point 16 . 1 . At this point the remainder of Example 1 proceeds from its second paragraph.
EXAMPLE 2
Person Tries to Enter/Exit With or Without a Weapon from Zone A
[0036] This might include a person trying to re-enter after passing through a one-way exit.
[0037] A person enters zone A from area F. The one way feature does not permit entry into zone C from zone A. The door panel 17 can be moved towards zone D when the person steps into zone D always energized switch 19 is closed and current flows from point 19 . 2 to latching relay 16 at point 16 . 1 .
[0038] Latching relay 16 is latched continuously and then current flows from point 16 . 3 to normally open flywheel magnetic switch 2 as a door panel 17 rotates to timing apprehension position shown by the lower right hand static structure denoted as 24 . Normally open magnetic switch 2 activates(closes) and current flows from point 2 . 2 to latching relay 18 at point 18 . 1 .
[0039] Latching relay 18 is continuously latched and current flows from point 18 . 3 to magnetic lock 5 at point 5 . 1 , to time delay switch 23 at point 23 . 3 and to telephone transmitter 11 at point 11 . 3 . Magnetic lock 5 locks flywheel 6 by inserting its plunger into cylinder 25 preventing further rotation of the door. The person is trapped within zone D. Telephone transmitter 11 calls 911 or a predetermined internal security number. Siren 12 sounds for 5 minutes or some other pre-selected time period.
[0040] The detained person can be released as described in Example 1 above, except that here the person will be freed into zone B.
EXAMPLE 3
Person Tries to Leave Through a Secured Exit With a Protected Item
[0041] Device 9 is configured as an electromagnetic detector or as a RF receiver. Zone E is positioned inside a store or other protected building/area. As a person reaches area E electromagnetic detector, 9 detects a magnetic strip attached to a protected item, e.g. a full length leather or fur coat, on the person and sends an electronic signal from point 9 . 3 through normally closed switch 7 to trigger relay 14 at point 14 . 1 . Alternatively where device 9 is a RF receiver, an employee or guard noticing a person attempting to leave with a protected item can transmit a signal to receiver 9 and the device 9 sends an electronic signal from point 9 . 3 above.
[0042] Next normally open relay 14 closes and reopens causing current flow from point 14 . 2 to latching relay 15 at point 15 . 1 . Latching switch 15 is latched continuously and current flows from point 15 . 3 to point 20 . 1 of normally open apprehension switch 20 . As the person enters zone C switch 20 is closed(activated) and current flows from point 20 . 2 to latching relay 16 at point 16 . 1 .
[0043] Latching relay 16 is latched continuously and then current flows from point 16 . 3 to normally open flywheel magnetic switch 2 as a door panel 17 rotates to timing apprehension position shown by the lower right hand static structure denoted as 24 . Normally open magnetic switch 2 activates(closes) and current flows from point 2 . 2 to latching relay 18 at point 18 . 1 .
[0044] Latching relay 18 is continuously latched and current flows from point 18 . 3 to magnetic lock 5 at point 5 . 1 , to time delay switch 23 at point 23 . 3 and to telephone transmitter 11 at point 11 . 3 . Magnetic lock 5 locks flywheel 6 by inserting its plunger into cylinder 25 preventing further rotation of the door. The person is trapped within zone C. Telephone transmitter 11 calls 911 or a predetermined internal security number. Siren 12 sounds for 5 minutes or some other pre-selected time period.
[0045] The detained person can be released when the proper 4 digit code is entered into key pad 10 . Key pad point 10 . 5 , which normally open, is closed and current flows to reset relay 13 at point 13 . 1 . Normally closed relay 13 opens and recluses disturbing the current flow to latching relays 15 , 16 , and 18 . Magnetic lock 5 is unlocked by the withdrawal of its plunger from cylinder 25 and the door may now rotate to allow the person to exit in zone A.
ALTERNATIVE EXAMPLE 3
Person Tries to Pass Protected Item Through Exit
[0046] Here the basic plan works the same, except for the following changes. The item moving from area E into zone B is detected by detector 9 . The leading door panel activates switch 20 and the protected item alone is detained within zone C as the magnetic lock 5 locks flywheel 6 .
EXAMPLE 4
Person Tries to Pass a Weapon Into the Building From a Protected Exit by Fastening it to a Door Panel
[0047] A person in zone A, which is outside the building or protected area, fastens in some manner a weapon onto door panel 17 to provide it to an accomplice within the protected area. As door panel 17 rotates into zone D, RF detector 3 detects the weapon and sends an electronic signal to latching relay 16 at point 16 . 1 .
[0048] Latching relay 16 is latched continuously and then current flows from point 16 . 3 to normally open flywheel magnetic switch 2 as a door panel 17 rotates to timing apprehension position shown by the lower right hand static structure denoted as 24 . Normally open magnetic switch 2 activates(closes) and current flows from point 2 . 2 to latching relay 18 at point 18 . 1 .
[0049] Latching relay 18 is continuously latched and current flows from point 18 . 3 to magnetic lock 5 at point 5 . 1 , to time delay switch 23 at point 23 . 3 and to telephone transmitter 11 at point 11 . 3 . Magnetic lock 5 locks flywheel 6 by inserting its plunger into cylinder 25 preventing further rotation of the door. The weapon is trapped within zone D. Telephone transmitter 11 calls 911 or a predetermined internal security number. Siren 12 sounds for 5 minutes or some other pre-selected time period.
[0050] The detained weapon can be released when the proper 4 digit code is entered into key pad 10 . Key pad point 10 . 5 , which normally open, is closed and current flows to reset relay 13 at point 13 . 1 . Normally closed relay 13 opens and recluses disturbing the current flow to latching relays 15 , 16 , and 18 . Magnetic lock 5 is unlocked by the withdrawal of its plunger from cylinder 25 and the door may now rotate to allow the retrieval of the weapon from zone B.
[0051] In all cases when there is no theft or entry/exit with an unauthorized weapon the ingress or egress is as facile as entry into general office building or hotel through a freely revolving door. Passage by authorized personnel carrying weapons can be made possible either by prior keying in of appropriate codes into keypad 10 or using computer programming to temporarily override the circuitry in conjunction with an entry of a proper code into the controlling computer.
[0052] Having described preferred embodiments of the invention with reference to the accompanying drawings, it is to be understood that the invention is not limited to these precise embodiments, and that various changes and modifications may be effected therein by one skilled in the art without departing from the scope or spirit of the invention as defined in the appended claims.
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An essentially automatic, robotic-like system to aid in preventing crime in high trafficked buildings and other public sites, using only low voltage power, is described. In various modes it can protect public buildings such as schools, stadiums, open air markets, banks, office buildings from entrance of persons carrying weapons or separately trying to pass weapons into a protected area, even in the event of general power loss. Here the invention provides a well designed, compact solution to weapons detection and the detainment of persons attempting to disrupt, destroy or harm citizens in public buildings such as schools, banks, etc. with a minimum of restriction of access by persons regularly using the facilities. In other variations, it can be used to prevent unauthorized removal of costly or dangerous items from protected buildings or areas. Here the invention similarly provides a substantially automatic method of detection and detection of persons attempting to illegally remove items either without paying or that are not for sale in a store setting.
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FIELD OF THE INVENTION
The invention relates to an impeller of a device for variable adjustment of the control times of gas exchange valves of an internal combustion engine with an essentially cylindrical hub element and at least one vane that extends outward in the radial direction starting from the hub element, wherein at least the hub element is produced from a non-metallic material.
BACKGROUND
In modern internal combustion engines, devices for the variable adjustment of the control times of gas exchange valves are used to be able to vary the phase relation between the crankshaft and camshaft in a defined angle range between a maximum advanced position and a maximum retarded position. The device is integrated in a drive train by means of which torque is transmitted from the crankshaft to the camshaft. This drive train can be realized, for example, as a belt, chain, or gearwheel drive. In addition, the device is locked in rotation with a camshaft and has one or more pressure chambers by means of which the phase relation between the crankshaft and the camshaft can be varied selectively.
Such a device is known, for example, from DE 10 2007 041 552 A1. The device has a cell wheel, an impeller, and two side covers, wherein the cell wheel is in driven connection with a crankshaft and the impeller is locked in rotation on a camshaft. Here, the impeller is arranged so that it can pivot relative to the cell wheel in a defined angle interval. The side covers are arranged on the axial side surfaces of the impeller and the cell wheel and locked in rotation with the cell wheel by means of screws. The impeller includes an essentially cylindrical hub element and several separate vanes. The vanes are arranged in vane grooves that are constructed on the cylindrical outer lateral surface of the hub element and extend outward in the radial direction. In the hub element there are several hollow spaces that extend in the axial direction and are open on both axial side surfaces of the hub element.
The cell wheel, the impeller, and the side covers bound several pressure spaces. Each of the pressure spaces is divided by one of the vanes into pressure chambers that act against each other and form a hydraulic adjustment drive by means of which the phase position between the impeller and the cell wheel can be varied. The pressurized medium supply to and the pressurized medium discharge from the pressure chambers is realized via pressurized medium channels formed in the hub element. The pressurized medium channels communicate on one side with a central opening of the impeller and on the other side with the pressure chambers. The pressurized medium channels are constructed as boreholes that are formed in the hub element after the shaping process of the hub element.
Another device is known from U.S. Pat. No. 5,836,277 A. In this embodiment, pressurized medium channels are constructed as radial grooves on the axial side surfaces of the impeller.
Another device is known from DE 101 34 320 A1. In this embodiment, the vanes are formed integrally with the hub element. The integrally formed impeller is made from a plastic.
The present invention is based on the objective of specifying a cost-optimized and weight-optimized impeller of a device for the variable adjustment of the control times of gas exchange valves of an internal combustion engine.
SUMMARY
This objective is met according to the invention in that the impeller is made from at least two sub-elements that are set opposite each other in the direction of an axis of rotation of the impeller and contact each other, wherein the sub-elements are connected to each other and wherein at least one recess is formed at least on one of the contacting side surfaces of the sub-elements.
The impeller has an essentially cylindrical hub element and at least one vane that extends outward in the radial direction starting from an outer cylindrical lateral surface of the hub element. The vane can be constructed, for example, integrally with the hub element. Alternatively, the vane can be produced separately from the hub element and connected to this element, for example, it can be inserted into a groove formed on the hub element. At least the hub element is made from a non-metallic material, for example, a plastic, wherein the weight of the impeller is reduced in comparison with metallic impellers. In addition, the vane could also be made from a non-metallic material. The impeller includes at least two sub-elements that are set opposite each other in the direction of an axis of rotation of the impeller and contact each other. Here, the separating plane of the sub-elements can be penetrated by the axis of rotation of the impeller, for example, vertically, so that an axial side surface of one sub-element contacts an axial side surface of another sub-element. The sub-elements are connected to each other, for example, by means of an adhesive connection or a weld connection (e.g., by means of ultrasonic welding) or by means of a non-positive-fit or positive-fit connection. In addition it is provided that at least one recess is formed at least on one of the side surfaces of the sub-elements that contact each other. The recesses could have already been produced during the shaping process. For example, these could be taken into account in the mold of an injection-molding tool. Through this construction of the impeller, the recess of a sub-element is closed in the axial direction by another sub-element. The recess can be formed, for example, with a blind hole shape. In this case, an outwardly closed hollow space is realized in the impeller, so that the weight and the material requirements for producing the impeller are reduced. After assembling the device, the axial side surfaces of the impeller form a sealing contact on the side covers of the device, in order to minimize leakage from the pressure chambers inward in the radial direction. Because there are no openings on the axial side surfaces of the impeller in the area of the hollow spaces, the sealing length is made longer in this area, wherein leakage is reduced.
Alternatively or additionally, the recess could be constructed as a groove that extends outward in the radial direction starting from a central opening of the impeller and opens into an area, for example, a pressure chamber, adjacent to the vanes in the peripheral direction. In this case, the grooves are covered, in turn, by another sub-element in the axial direction. The grooves could thus be used as pressurized medium channels for feeding pressurized medium to or for discharging pressurized medium from the pressure chambers. Through this construction of the pressurized medium channels, these are arranged within the impeller, without cost-intensive post processing steps, for example, drilling the pressurized medium channels, being necessary. Because pressurized medium is led in this embodiment within the impeller to the pressure chambers and does not come in contact with one of the side covers, no transverse forces act on the impeller, wherein these forces would press the impeller against one of the side covers and thus would increase the wear at this point.
BRIEF DESCRIPTION OF THE DRAWINGS
Additional features of the invention can be found in the following description and from the drawings in which an embodiment of the invention is shown in simplified form. Shown are:
FIG. 1 only very schematically, an internal combustion engine,
FIG. 2 a device for the variable adjustment of the control times of gas exchange valves of an internal combustion engine in a top view along the axis of rotation of the device with an impeller according to the invention,
FIG. 3 a perspective view of the impeller from FIG. 2 ,
FIG. 4 a sub-element of the impeller from FIG. 3 in a top view, and
FIG. 5 a perspective diagram of the sub-element from FIG. 4 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In FIG. 1 , an internal combustion engine 1 is shown schematically, wherein a piston 3 sitting on a crankshaft 2 is indicated in a cylinder 4 . The crankshaft 2 connects to an intake camshaft 6 or an exhaust camshaft 7 in the illustrated embodiment by means of a traction mechanism drive 5 , wherein a first and a second device 11 for the variable adjustment of the control times of gas exchange valves 9 , 10 can provide for a relative rotation between the crankshaft 2 and the camshafts 6 , 7 . The cams 8 of the camshafts 6 , 7 actuate one or more intake gas exchange valves 9 and one or more exhaust gas exchange valves 10 , respectively.
FIG. 2 shows a device 11 according to the invention in a top view along an axis of rotation 33 of the device 11 . The device 11 has a cell wheel 14 , an impeller 15 , and two side covers 16 . The side covers are arranged on axial side surfaces of the cell wheel 14 and attached to this by means of screws 12 . In FIG. 2 , only the rear side cover 16 is shown. The impeller 15 is made from a suitable plastic and has an essentially cylindrical hub element 17 from whose outer cylindrical lateral surface five vanes 18 extend outward in the radial direction. In the illustrated embodiment, the vanes 18 are formed integrally with the hub element 17 . Also conceivable are embodiments in which the vanes 18 are formed separately from the hub element 17 and are arranged in vane grooves that are formed on the cylindrical lateral surface of the hub element 17 . In this case, the vanes 18 can also be produced from plastic. Also conceivable are vanes 18 made from a metallic material, for example, from steel.
Starting from an outer peripheral wall 19 of the cell wheel 14 , five projections 20 extend inward in the radial direction. In the illustrated embodiment, the projections 20 are formed integrally with the peripheral wall 19 . The cell wheel 14 is supported on the impeller so that it can rotate relative to this impeller 15 by means of radially inner peripheral walls of the projections 20 .
On the not-shown side cover, a similarly not-shown chain wheel is formed by means of which torque can be transmitted from the crankshaft 2 to the cell wheel 14 by means of the traction mechanism drive 5 . The impeller 15 is locked in rotation with the camshaft 6 , 7 in the assembled state. For this purpose, the impeller 15 has a central opening 13 that is penetrated by a not-shown central screw that is screwed to the camshaft 6 , 7 .
Within the device 11 , a pressure space 21 is formed between every two projections 20 adjacent in the peripheral direction. Each of the pressure spaces 21 is bounded in the peripheral direction by adjacent projections 20 , in the axial direction by the side covers 16 , inward in the radial direction by the hub element 17 , and outward in the radial direction by the peripheral wall 19 . In each of the pressure spaces 21 , a vane 18 projects, wherein the vanes 18 contact both the side covers 16 and also the peripheral wall 19 . Each vane 18 thus divides the respective pressure space 21 into two counteracting pressure chambers 22 , 23 .
By pressurizing a group of pressure chambers 22 , 23 and depressurizing the other group, the phase position of the impeller 15 to the cell wheel 14 and thus the phase position of the camshaft 6 , 7 to the crankshaft 2 can be varied. By pressurizing both groups of pressure chambers 22 , 23 , the phase position can be kept constant.
The impeller 15 has a blind-hole-like receptacle 31 that is formed open on an axial side surface of the impeller. A locking pin 32 that can move in the axial direction is held in the receptacle 31 , wherein a force is applied to this locking pin by a spring in the direction of the not-shown side cover. The not-shown side cover has a slot in which the locking pin 32 can engage when this is opposite the slot in the axial direction. Thus, a mechanical coupling between the impeller 15 and the cell wheel 14 can be produced and can be disconnected by feeding pressurized medium to the slot.
The impeller 15 is formed of two sub-elements 24 ( FIG. 3 ) that are set opposite each other and contact each other along a separating plane running in the illustrated embodiment perpendicular to the axis of rotation 33 of the device 11 or the impeller 15 . The two sub-elements 24 are attached to each other by means of an adhesive connection.
The side surfaces 25 of the sub-elements 24 contacting each other have several recesses 26 ( FIGS. 4 and 5 ). First recesses 26 are constructed as radial grooves 27 . The grooves 27 extend up to an opening on the outer cylindrical lateral surface of the hub element 17 starting from a ring channel 28 formed in the central opening 13 . Here, the grooves 27 simultaneously extend into the area of the vanes 18 . The grooves 27 thus communicate with an area of the pressure chambers 22 , 23 , adjacent to the vanes 18 in the peripheral direction. Both sub-elements 24 have identical forms with respect to the grooves 27 , so that after their assembly, the grooves 27 of one sub-element 24 are closed in the axial direction by an area of the side surface 25 of the other sub-element 24 . Thus, the grooves 27 are used as pressurized medium channels by means of which pressurized medium can be fed from the ring channels 28 to the pressure chambers 22 , 23 or pressurized medium can be discharged from the pressure chambers 22 , 23 to the ring channels 28 . Through the construction of the pressurized medium channels as grooves 27 in the sub-elements 24 , it is achieved that the pressurized medium channels are not constructed on an axial side surface of the impeller 15 . Thus, no axial forces act on the impeller 15 when the grooves 27 are pressurized, wherein the frictional forces between the side covers 16 and the side surfaces of the impeller 15 are minimized. In addition, the grooves 27 are formed without added costs during the shaping process of the sub-elements 24 , for example, during an injection molding process. Thus, no additional metal-cutting post processing steps, for example, drilling of the pressurized medium channels, are necessary.
In addition to the grooves 27 , second recesses 26 that are constructed as blind holes 29 are provided on the side surfaces 25 of the sub-elements contacting each other. The only opening of the blind holes 29 is in the joint plane of the two sub-elements 24 . Thus, the axial side surfaces of the impeller 15 are formed without recesses. The blind holes 29 can also be formed during the shaping process of the sub-elements 24 . Thus, the material costs and the weight of the impeller 15 are reduced. Simultaneously, the sealing effect between the side covers 16 and the hub element 17 is increased due to the smooth side surfaces of the impeller 15 , so that leakage from the pressure chambers 22 , 23 to the central opening 13 is reduced.
Each of the sub-elements 24 has, in addition to the described structures, positive-fit elements 30 that are formed in the vanes 18 . Here, a peg is formed on each of two vanes 18 and an opening adapted to the peg is formed on each of two additional vanes 18 . When the sub-elements 24 are joined, the pegs engage in the corresponding openings, so that the sub-elements 24 are automatically positioned relative to each other.
The two sub-elements 24 have identical constructions, so that only one injection-molding mold is required for their production.
Reference Symbols
1 Internal combustion engine
2 Crankshaft
3 Piston
4 Cylinder
5 Traction mechanism drive
6 Intake camshaft
7 Exhaust camshaft
8 Cam
9 Intake gas exchange valve
10 Exhaust gas exchange valve
11 Device
12 Screw
13 Central opening
14 Cell wheel
15 Impeller
16 Side cover
17 Hub element
18 Vane
19 Peripheral wall
20 Projection
21 Pressure space
22 First pressure chamber
23 Second pressure chamber
24 Sub-element
25 Side surface
26 Recess
27 Groove
28 Ring channel
29 Blind hole
30 Positive-fit element
31 Receptacle
32 Locking pin
33 Axis of rotation
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An impeller ( 15 ) of a device ( 11 ) for variable adjustment of the control times of gas exchange valves ( 9, 10 ) of an internal combustion engine ( 1 ) having a substantially cylindrical hub element ( 17 ) and at least one blade ( 18 ) which extends radially to the outside proceeding from the hub element ( 17 ), wherein at least the hub element ( 17 ) is produced from a non-metallic material.
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BACKGROUND OF THE INVENTION
[0001] This invention relates to reciprocating machines such as internal combustion engines or compressors of the type having a cylinder block having one or more cylinder bores that reciprocally support a piston or pistons that are connected a crankshaft at one end. The opposite end of these cylinder bores is closed by a cylinder head affixed to the cylinder block in a suitable manner. The flow into and out of the cylinder bores is controlled by valves reciprocally mounted in the cylinder head and operated by one or more camshafts journalled therein. Frequently the valves are operated from cams on the camshaft through pivotally supported rocker arms.
[0002] Although this arrangement is generally effective, a substantial number of machining and assembly steps are required to complete the assembly. This adds to the cost and can, if not closely controlled, present alignment problems that can introduce inaccuracies and less than desirable operation.
[0003] As an example of a prior art construction of this type, Japanese Published Application, Publication Number P2000-170506A shows a construction wherein an intake side camshaft and an exhaust side camshaft are journalled by underlying lower cam holders and overlying upper cam holders. The lower cam holders condition are fastened to the cylinder head via a first series of fasteners. In addition, the upper cam holder and lower cam holder are fastened to each other at positions spaced inward from the first fasteners. In addition the second fastening members each have a smaller diameter than the first fastening member.
[0004] It is also stated therein that that size reduction of the cylinder head is possible and the first fastening members also serve to resist undesired cocking of the rocker shafts. However much fitting and precise location is required for machining and assembly.
[0005] As a further disadvantage to this type of construction, to secure the positional accuracy of the rocker shaft support section formed on the lower cam carrier, line boring is necessary after the lower cam carriers are mounted independently on each cylinder head. Therefore, the scale of machining facilities for such line boring become larger.
[0006] In addition, since the rigidity of hole machining tools needs to be secured to secure the machining accuracy, size reduction of the tool diameter is difficult. Therefore, weight saving and size reduction of the rocker shaft are difficult and in turn, weight saving and size reduction of the rocker arm are also difficult.
[0007] Another prior art structure is shown in Japanese Patent Publication B 2537205. As shown therein each rocker shaft is configured to be supported pivotally on a respective one of a plurality of cam carriers. Therefore, when the cam carriers are assembled to the cylinder head, they need to be assembled in succession while rocker arms are fitted on the rocker shafts, causing complicated assembly work.
[0008] In addition, each rocker shaft should not to overlap the opening that receives the respective spark plug insert. Therefore the support section for each of the rocker shafts needs to be separately machined for each cam carrier, making positional accuracy is difficult to obtain.
[0009] Therefore it is a principal object of this invention to provide a simplified, low cost and easily manufactured and assembled arrangement for operating the valves of a multi cylinder and valve reciprocating machine.
SUMMARY OF THE INVENTION
[0010] This invention is adapted to be embodied in a low cost, easily manufactured and assembled valve actuating mechanism for a reciprocating machine having a cylinder head adapted to be affixed in closing relation to at least one cylinder bore formed in a cylinder block. A cam shaft carrier is affixed to the cylinder head and defines a cam shaft bore for journaling a bearing surface of a cam shaft. A rocker shaft journal is formed by the cam shaft carrier in parallel relation to the cam shaft bore and extends on at least one side of the cam shaft bore. A rocker arm is journalled by the rocker shaft journal and has a follower surface engaged by a cam lobe of the cam shaft.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a top plan view of the cylinder head of a reciprocating machine constructed in accordance with a first embodiment of the invention, with the cam cover removed to more clearly show the construction.
[0012] FIG. 2 is a further enlarged view of this embodiment, with the cam shafts removed.
[0013] FIG. 3 is a side elevational view looking in the direction of the arrow 3 in FIG. 2 showing the valves operated in phantom.
[0014] FIG. 4 is a cross sectional view taken along the line 4 - 4 in FIG. 3 .
[0015] FIG. 5 is a cross sectional view taken along the line 5 - 5 in FIG. 3 .
[0016] FIG. 6 a is an enlarged view taken generally along the line 6 - 6 in FIG. 2 and shows the condition when the associated valve is closed.
[0017] FIG. 6 b is an enlarged view taken generally along the line 6 - 6 in FIG. 2 and shows the condition when the associated valve is opened.
[0018] FIG. 7 is a view in part similar to FIG. 2 and shows another embodiment of the invention.
[0019] FIG. 8 is a side elevational view looking in the direction of the arrow 7 in FIG. 6 showing the valves operated in phantom.
[0020] FIG. 9 is a top plan view, in part similar to FIG. 1 , but with the cylinder head reversed, and shows still another embodiment of the invention.
[0021] FIG. 10 is a further enlarged view of the embodiment of FIG. 9 , showing one of the center cam shaft carriers with the cam shafts removed.
[0022] FIG. 11 is a side elevational view looking in the direction of the arrow 11 in FIG. 10 showing the valves operated and the operating cam lobes in phantom.
[0023] FIG. 12 is a cross sectional view taken along the line 12 - 12 in FIG. 11 .
[0024] FIG. 13 is a top plan view, in part similar to FIGS. 2, 7 , and 10 showing only the two cam carriers of this embodiment provided at the opposite ends of the cylinder head
[0025] FIG. 14 is a cross sectional view of the embodiment of FIG. 13 taken along a plane passing through the axes of the rocker arm journals.
DETAILED DESCRIPTION
[0026] Referring now in detail to the drawings and initially to the embodiment of FIGS. 1-6 , a multi-cylinder reciprocating machine is shown partially and is identified generally by the reference numeral 21 . As will be readily apparent to those skilled in the art, the invention may be applied to either reciprocating internal combustion engines or compressors. However to simplify the disclosure only engine applications are illustrated.
[0027] In the illustrated embodiment of these figures ( FIGS. 1-6 ), a cylinder head, indicated generally at 22 is suitably affixed to a cylinder block (not shown). Basically any number of cylinders and any engine configuration may be employed such as in line, v type or opposed.
[0028] In accordance with the invention, a plurality of cam carriers 23 are provided on the cylinder head 22 in a manner to be described shortly. The cam carriers 23 support for rotation an intake cam shaft 24 and an exhaust cam shaft 25 disposed parallel to each other. To this end, the cam carriers 23 are formed by a single lower piece 23 a having lower bearing recesses 23 i and 23 e each associated with respective, axially spaced journal surfaces 24 b and 25 b of the respective intake and exhaust cam shafts 24 and 25
[0029] To further complete the journaling of the cam shafts 24 and 25 , bearing caps 26 i and 26 e are affixed, in a manner to be described shortly, to the single lower piece 23 a and the cylinder head 22 . These bearing caps have bearing surfaces 26 ib and 26 eb that are complementary to the lower bearing recesses 23 i and 23 e . These bearing surfaces 26 ib and 23 i and 26 eb and 23 e embrace and journal the axially spaced cam shaft bearing sections 24 b and 25 b of the cam shafts 24 and 25 , respectively.
[0030] The driven ends of the cam shafts 24 and 25 are also journalled directly in the end of the cylinder head 22 by end bearing caps also indicated by the reference numerals 26 ie and 26 ee.
[0031] Threaded fasteners 27 pass through bored holes 28 in the bearing caps 26 i , and 26 e and aligned holes 29 formed in the single lower pieces 23 a to fix the elements together. At the driven end of the camshafts 24 and 25 the end bearing caps 26 ie and 26 ee are bored to cooperate with tapped holes formed in the cylinder head at the driven end. Finally the lower ends 27 e of all of these threaded fasteners 27 are threaded into tapped holes formed in the cylinder head 22 to complete the assembly.
[0032] In addition a further pair of bored holes 28 are formed in axial alignment with the transverse center of the cylinder head 22 in the area of the single lower pieces 23 a between the bearings 23 i and 23 e above tapped holes in the cylinder head 22 to receive further threaded fasteners 30 for additional security in retaining the lower pieces 23 a when the bearing caps 26 i and 26 e are removed,
[0033] Continuing to refer primarily to FIG. 1 , the intake cam shaft 24 is formed with a plurality of intake cams 24 c , and the exhaust cam shaft 25 is formed with a plurality of exhaust cams 25 c . These pluralities of cams 24 c and 25 c are each adapted to operate the intake and exhaust valves, to be described shortly, through respective intake and exhaust rocker arms 31 and 32 .
[0034] To this end, the single piece 23 a of each of the cam carriers 23 is formed with an intake side rocker shaft journal opening 23 irj and an exhaust side rocker shaft opening 23 erj in a rocker shaft support section 23 ras located between the intake cam shaft bearing 23 i and the exhaust cam shaft bearing 23 e , as shown in FIGS. 2 and 3 .
[0035] Intake and exhaust rocker shafts 33 , 34 , respectively, are supported by the rocker shaft support portions 23 ras , as shown in FIGS. 1-4 . The rocker shaft support section 23 ras is provided on both sides of the cam shaft bearings 23 i and 23 e and extends in the same direction as the cam shafts 24 , 25 (see FIG. 1 ).
[0036] The rocker shaft journal openings 23 irj , 23 erj are formed in the cam carrier 23 as through-holes passing through the rocker shaft support section 23 ras . The rocker shafts 33 , 34 are inserted in these rocker shaft through-holes 23 irj , 23 erj.
[0037] In addition to the structure as thus far described, the single lower piece 23 a of each of the cam carriers 23 is formed with a hole 35 for a spark plug insert section between the intake rocker arm support 23 irj and the exhaust rocker arm support 23 erj . This hole extends in a direction perpendicular to the axial direction of these shaft receiving sections 23 irj , 23 erj , as shown in FIGS. 1, 2 and 4 .
[0038] A cylindrical collar 36 is fitted In the hole 35 for each ignition plug insert section formed in the cam carrier 23 , as shown in FIG. 1 . Suitably mounted ignition plugs 37 serve the combustion chambers formed in part by the cylinder head 22 through the collars 36 .
[0039] In addition to this purpose, the collars 36 also have the function of preventing the rocker shafts 33 , 34 from slipping off the cam carrier 23 . This is accomplished by forming the rocker shafts 33 and 34 with notches 33 a and 34 a , respectively to engage parts of the collar 36 for the prevention of their slipping-off.
[0040] It is arranged so that the linear thermal expansion coefficient of the collar 36 is different (either larger or smaller) than that of the cam carrier 23 . This will insure that the collar 36 can be attached to and detached from the cam carrier 23 in a cold or a hot environment and subsequently the collar 36 will be prevented from slipping off the cam carrier 23 at room temperature. Such an arrangement improves handling properties of the cam carrier 23 , as well as its assembling properties, and a slipping-off prevention condition can be realized of a minimum amount of play as compared with mechanical fasteners such as bolts.
[0041] As best seen in FIGS. 2 and 4 , the cam carrier lower pieces 23 a are formed with slots 23 as and intake side rocker arms 31 and exhaust side rocker arms, 32 are inserted in these slots 23 as. The rocker arms 31 , 32 are formed with shaft insert holes 31 a , 32 a , respectively for journaling rocker arms 31 and 32 in the lower pieces 23 a on their shafts 33 and 34 .
[0042] With the intake side rocker arms 31 fitted in the slots 23 as of the cam carrier 23 , the intake side rocker shaft 33 is inserted in the intake side rocker shaft through-holes 23 irj and shaft insert hole 31 a . Likewise, with the exhaust side rocker arm 32 fitted in the slot 23 as of the cam carrier 23 , the exhaust side rocker shaft 34 is inserted in the exhaust side rocker shaft through-hole 23 erj and shaft insert hole 32 a . The rocker shafts 33 , 34 are supported independently for each cam carrier 23 , and pass through the rocker shaft support section 23 ras of the cam carrier 23 and extend on both sides of the cam shaft bearing section 24 b so as to be disposed parallel to the cam shafts 24 , 25 . Thus the rocker arms 31 , 32 are supported for rotation by the rocker shafts 33 , 34 on both sides of the cam shaft bearing section 26 ib of the cam carrier 23 .
[0043] When the intake side cam shaft 24 and exhaust side cam shaft 25 are rotated, each of the intake side cams 24 c and exhaust side cams 25 c depresses each of the intake side rocker arms 31 and exhaust side rocker arms 32 for opening or the action of the springs, to be described, releases the depression and permits the rocker arms and associated valves to move to the closed positions.
[0044] The cam carriers 23 are mounted approximately directly above each respective cylinder and configured such that all of the plurality of rocker arms 31 , 32 supported on both sides of the cam shaft bearing section 26 ib of the cam carrier 23 , correspond to that respective cylinder. Thus and as best seen in FIG. 3 , each of the valves, indicated generally by the reference numeral 38 , serving a respective one cylinder are adapted to be opened/closed by the movement of the four rocker arms 31 , 32 supported on the two rocker shafts 33 , 34 of one cam carrier 23 .
[0045] Referring now primarily to FIGS. 2-5 , and 6 a and 6 b , it will be seen that the upper bearing halves 26 ib and 26 eb have the aforementioned aligned holes 29 through which the threaded fasteners 27 pass along with the aligned bores 28 of the single lower piece 23 a for the fastening of these assemblies to the cylinder head 22 in the desired relation to the associated cylinder.
[0046] As another feature of the invention, the cam carriers 23 also cooperate to lubricate the valves and operating mechanism. To this end, the single lower piece 23 a of each cam carrier 23 is formed with an oil passage, indicated generally at 39 , shown in FIGS. 2, 3 and 6 a and 6 b . This oil passage receives 39 pressurized oil from the engine lubricating system in a suitable manner and communicates with oil passages 41 , 42 , respectively, extending toward the intake rocker shaft 33 and exhaust rocker shaft 34 . These passages 41 and 42 communicate respectively with coaxial oil passages 43 , 44 , formed in the rocker arm shafts 33 and 34 respectively. To this end, the rocker shafts 33 , 34 are each formed hollow inside and closed at both ends to form the oil passages 43 and 44 .
[0047] The valve gear lubricating system also includes oil delivery notches 31 d and 32 d formed in the intake rocker arms 31 and exhaust rocker arms 32 , respectively. These oil delivery notches 31 d and 32 d are formed at the outer ends of delivery passages 43 and 44 that communicate with the rocker arm passages 41 and 42 , respectively and face toward the intake cams 24 c and exhaust cams 25 c , shown partially in FIGS. 6 a and 6 b . As best seen in FIG. 4 , the rocker shafts 33 , 34 are retained axially by notches 33 a , 34 a formed therein that are engaged by the collar 36 .
[0048] The valves 38 associated with the structure already described, their operation and construction will now be described in more detail by reference to FIG. 3 . Each valve 38 is of the poppet type and has a valve stem 45 that is supported for reciprocation in the cylinder head 22 by a respective valve guide 42 pressed or otherwise secured to the cylinder head 22 . A valve head 46 at the lower end of the respective stem cooperates with a valve seat (not shown) fixed at the combustion chamber end of the cylinder head 22 to control the flow through a respective intake or exhaust port, not shown in this figure, but as well known to those skilled in this art.
[0049] The valves 38 are normally retained in closed positions, as also known in the art, by return springs 47 of a desired type, with coil springs shown by way of example. These springs 47 are loaded between retainers 48 engaged with the cylinder head 22 and keeper retainers 49 fixed to the upper ends of the respective valve stem 45 to normally urge the valves 38 to their closed positions as shown in FIGS. 3 and 6 a.
[0050] As the respective cam shafts 24 and 25 rotate, their cam lobes 24 c and 25 c will act to drive the respective valves 38 to their opened positions as shown in FIG. 6 b , with compression of the springs 47 . Upon continued rotation of the respective cam shaft 24 and 25 their lobes 24 c and 25 c will move away from the stems 45 and the springs 47 will close the valves 38 , as is well known in the art.
[0051] As has also been noted, the oil delivery system for lubricating the valve train including the cam shafts 24 and 25 and specifically their respective cam lobes 24 c and 25 c , the contacted surfaces of the rocker arms 31 and 32 and the stems of the operated valves insures adequate lubrication. However a system is also incorporated for controlling the amount of lubricant supplied to these areas so as to prevent excess oil flow. This system is described in connection with the exhaust valves but it should be understood that the intake valves are lubricated by the same type of flow controlling construction
[0052] The oil or other lubricant is delivered continuously to the hollow interior of the respective rocker arm shaft, this being the passage 44 in the case of the exhaust valves 45 from the carrier base 23 a through a delivery opening 44 i that is continuously open since the rocker arm shaft 34 does not rotate. However the rocker arm 32 does rotate and its delivery passage 42 only overlaps a discharge opening 44 d in the associated rocker arm 32 only at the time the associated rocker arm is moved toward the valve opening positions, as shown by comparing FIG. 6 b with FIG. 6 a.
[0053] To summarize the operation of this embodiment, as the engine 21 operates and the cam shafts 24 , 25 and their plurality of cams 24 c , 25 c rotate, and the cams 24 c , 25 c depress will sequentially pivot the rocker arms 31 , 32 , and the valve stems 33 are lowered along with their valve faces 32 air is taken in on the intake side and combustion gas is exhausted on the exhaust side as is well known in the art.
[0054] In a like manner, when the cams 24 c , 25 c rotate beyond the condition of depressing the rocker arms 31 , 32 , the valve stems 33 are raised by the action of the springs 47 and the valve faces 32 are also raised to close their respective seats (not shown) so that no air will be taken in on the intake side and no exhaust gas will be exhausted on the exhaust side. The lubrication of the operating mechanism is effected only when the valves are being operated so as to avoid excess lubrication.
[0055] Thus, as should be readily apparent to those skilled in the art, the embodiment of FIGS. 1-6 incorporates cam shafts 24 , 25 having a plurality of cams 24 c , 25 c for depressing rocker arms 31 , 32 journalled by a plurality of cam carriers 23 each formed integrally with cam shaft bearing sections 26 ib and 26 eb for supporting the cam shafts and rocker shaft support sections 23 irj and 23 erj for supporting rocker shafts 33 and 34 . The rocker shafts 33 , 34 each supported independently by a cam carrier 23 , positioned in the rocker shaft support section 23 ras of the cam carrier 23 and extending on both sides of the cam shaft bearing section 26 ib . Thus the axes of the cam shafts 24 , 25 , support of the rocker arms 31 , 32 on the rocker shafts 33 , 34 on both sides of the cam bearing section 26 ib of the cam carrier 23 are also parallel.
[0056] Therefore, since a plurality of cam carriers 23 are provided and the rocker shaft 33 , 34 are adapted to pass independently through respective of the rocker shaft support sections 23 ras of the cam carriers 23 , not all the plurality of rocker shafts 33 , 34 need be centered to facilitating assembly. Further, since the rocker shaft 33 , 34 are divided for each cam carrier 23 and small in length, weight saving and size reduction can be effected. Further, smaller scale, machining facilities for the cam carriers 23 can be employed. In addition, the positional accuracy of the holes for supporting rocker shafts 33 , 34 to the cam shaft bearing sections 26 ib 26 eb can be obtained easily, resulting in improvement in reliability. Moreover, the work in mounting the rocker shafts 33 , 34 to the arm carrier 33 is decreased.
[0057] As added advantages, the rocker shaft support section 23 ras extend on both sides of the cam shaft bearing section 26 ib in the same direction as the cam shafts 24 , 25 and is formed with slots 23 as for supporting the rocker arms 31 , 32 . The rocker shaft support section 23 ras is formed with through-holes 23 irj , 23 erj passing therethrough across the slots 23 as, and the rocker shafts 33 , 34 are inserted in the through-holes 23 irj , 23 erj . Therefore, since the rocker arms 31 , 32 are held by the slots 23 as on both sides in the vicinity of the shaft insert holes 31 a , 32 a , the rigidity of the mounting of the rocker arms 31 , 32 along with accurate movement of the rocker arms 31 , 32 , effecting higher rotation speed and improvement in reliability.
[0058] As a further advantage, the cam carriers 23 , the rocker shafts 33 , 34 and the rocker arms 31 , 32 have passages 39 , 41 , 42 , 43 , 44 for oil supplied from the cylinder head 22 and the rocker shaft 33 , 34 are hollow inside and closed at both ends with the notches 33 a , 34 a being covered by the collar 36 . Therefore, leakage of oil passing through the rocker shafts 33 , 34 from the notches 33 a , 34 a can be suppressed. This structure allows the hollow portions inside the rocker shaft 33 , 34 to be increased in size, effecting weight saving of the rocker shafts 33 , 34 .
[0059] Although in the multi-cylinder internal combustion engine 21 according to the embodiment of FIGS. 1-6 b , the rocker shafts 33 , 34 also pass through the rocker shaft support section 23 ras , this invention is not limited to that specific way the rocker shafts 33 , 34 are supported. Also, although in this first embodiment, the rocker shafts 33 , 34 extending on both axial sides of the cam shaft bearing section 26 ib to be disposed parallel to the cam shafts 24 , 25 , this invention is not limited to the foregoing embodiment.
Embodiment of FIGS. 7 and 8
[0060] To this end, FIGS. 7 and 8 show another embodiment of the invention. In describing this embodiment as well as those following, the same parts as in previous embodiments of the invention are designated by same reference numerals and description will not be repeated, except as necessary for those skilled in the art to understand and practice this and other additional embodiments to be described.
[0061] This embodiment employs cam carriers identified generally by the reference numeral 123 (only one of which is shown). In this embodiment rocker shaft through-holes 123 e , 123 i are formed in respective rocker shaft support sections 123 erj and 123 irj positioned transversely outside a cam shaft bearing section, indicated generally at 124 . The central part of this cam shaft bearing section 124 includes a portion defining a cylindrical opening 125 for receiving a respective collar (not shown) like the collars 36 of the previously described embodiment to hold a respective spark plug. These components are formed so that the linear thermal expansion coefficient of the collar 36 is different (either larger or smaller) than that of the cam carrier 123 , as described in the previous embodiment. This will insure that the collar 36 can be attached to and detached from the cam carrier 123 in a cold or a hot environment and subsequently the collar 36 will be prevented from slipping off the cam carrier 123 at room temperature.
[0062] In this embodiment, unlike that of FIGS. 1-6 the spark plug collar receiving opening 125 is separated from the rocker arm support sections 123 irj and 123 erj by the remainder of the cam shaft bearing section 124 . Other effects and functions are substantially the same as in the first described embodiment of this FIGS. 1-6 , except that while the rocker shafts 33 , 34 on which the rocker arms 31 , 32 rotate, are disposed inwardly in the first embodiment, they are dispose outwardly in this embodiment.
Embodiment of FIGS. 9 - 14
[0063] Another embodiment of the invention is illustrated in FIGS. 9-14 . Again where the elements of this embodiment are the same or substantially the same as components already described, those components have been identified by the same reference numerals as previously employed. Also and for the sake of brevity these components will be described only insofar as is necessary for those skilled in the art to practice this embodiment.
[0064] The engine associated with this embodiment and more particularly a cylinder head assembly thereof is indicated generally by the reference numeral 201 . The cylinder head 201 of the multi-cylinder internal combustion engine in this embodiment is different from the multi-cylinder internal combustion engine 21 of first described embodiment of FIGS. 1-6 b in the following aspects and is also shown in a reversed position therefrom.
[0065] Primarily, rather than operating all of the intake and exhaust valves associated with the same cylinder, the cam carriers, except for those at the ends of the of the cylinder head, as to be described shortly, operate one intake valve and one exhaust valve of pairs of the adjacent cylinders spanned by these paired, middle or central cam carriers, each of which is indicated generally by the reference numeral 223 m.
[0066] Like the previous embodiments and as best seen in FIGS. 10-12 , these middle cam carriers 223 m are comprised of a single lower piece 223 ma to which a pair of respective upper bearing halves 223 mib and 223 meb is affixed by threaded fasteners 227 . These middle cam carriers 223 m are each disposed between adjacent centermost cylinders, as should be readily apparent from FIG. 9 . The construction for the support at the ends of the cylinder head assembly 201 will, as has been noted, described later.
[0067] Continuing to refer primarily to FIGS. 10-12 , pairs of adjacent middle intake rocker arms 231 c are supported on an intake pivot shaft 224 received in a suitable bore formed in single lower pieces 223 ma of the middle cam carriers 223 m . The inner ends of these middle intake rocker arms 231 c are retained in slots 223 mas formed at one side of the single lower piece 223 ma.
[0068] In a like manner adjacent middle exhaust rocker arms 232 c are supported on an exhaust pivot shaft 234 recieved in a suitable bore formed in the single lower pieces 223 ma of the middle cam carriers 223 m . The inner ends of these middle exhaust rocker arms 232 c are also retained in slots 223 mas formed in the single lower pieces 223 ma of the middle cam carriers 223 m.
[0069] The middle intake rocker arm shafts 224 and the middle exhaust rocker arm shafts 234 are retained in axial position in the slots 223 mas and the single lower pieces 223 ma of the middle cam carriers 223 m in the manner now to be described. As with all of the embodiments described, threaded fasteners pass through bored holes in the respective components of the cam carriers of the embodiments. These bored holes in this embodiment are identified by the reference numerals 228 . As with the previously described embodiments, the body of the cylinder head ( 201 in this embodiment) has tapped holes to threadingly engage and retrain the threaded lower ends of the fasteners 227 . In addition and as best shown in FIG. 12 , these fasteners 227 pass through a portion of the bores 228 which intersect the pivot shafts 224 and 234 and around which sleeves 229 are positioned to axially restrain them axially. These sleeves 229 are also received in notches 230 formed in the pins 224 and 234 to axially restrain them within their respective bores.
[0070] From the description of this embodiment as already made, it should be obvious to those skilled in the art, that provision must be made for operating one intake valve and one exhaust valve for the cylinders at opposite ends of the cylinder head 201 . This structure may be best understood by reference to FIGS. 13 and 14 . As already noted, FIG. 13 is a top plan view showing only this portion of the structure of this embodiment and FIG. 14 is a cross sectional view of the structure shown in FIG. 13 taken through the pivotal axes of the rocker arms. The end intake rocker arms are identified by the reference numerals 231 e and the end exhaust rocker arms are identified by the reference numeral 232 e.
[0071] Referring now first to FIG. 13 and remembering its relation to FIG. 9 , at the respective left and right ends of the cylinder head 201 , end cam carriers 223 el and 223 er are provided to support the respective end intake rocker arms 231 e and end exhaust rocker arms 232 e for the cylinders provided at the left and right ends of the cylinder head 201 . These cam carriers 223 el , 223 er are each formed generally in the same shape as the middle cam carriers 223 m but are shorter and less complex in some regards because they each only journal one intake rocker arm 231 e and one exhaust rocker arm 232 e . Furthermore and as best seen in FIG. 14 , the respective rocker shafts 224 e and 234 e are shorter in length than the rocker shafts 224 and 234 of the middle cam carriers since they only carry one rocker arm.
[0072] Since the end cam carriers 223 el and 223 er journal respective ends of the camshafts 24 and 25 they are each provided with respective upper pieces 223 eib and 223 eeb that are fixed in place by the fasteners 227 in the manner as discussed with the other embodiments.
[0073] The lubrication system associated with the end cam carriers 223 el and 223 er is generally the same as that for the middle cam carriers and their associated components, as shown in FIG. 14 , except for the fact that it is only for two valves rather than four valves and thus it will not be described again in detail, but like components are identified by like reference numerals.
[0074] In the multi-cylinder internal combustion engine of the previous embodiments the cam carriers have been associated respectively with a single cylinder. They have thus been centered over the axis of the associated cylinder bore of the cylinder block. Thus the collars 36 have passed through the central openings that receive them. Also, as has been noted, this affords the opportunity to use materials of different thermal expansion to assure retention. The same effect is obtained with this embodiment, as will now be described.
[0075] As described, the middle cam carriers 223 m are each mounted between adjacent cylinders. In addition these middle cam carriers 223 m have a length that is somewhat less than the distance between adjacent cylinder axes. Thus there is in fact a gap between adjacent ends of the middle cam carriers 223 m . In addition there is a like gap between the end cam carriers 223 el 223 er and their adjacent middle cam carriers 223 m . Thus the adjacent ends are formed with semi-cylindrical notches 241 that are complimentary to the lower portions of the cylindrical collars 36 . Therefore, even in the multi-cylinder internal combustion engine 201 having an ignition plug 37 dispose above each cylinder, the cam carriers 223 m can be configured such that they don't obstruct the disposition of ignition plugs 37 . Thus, the degree of freedom in designing can be increased for the disposition of cam carriers 223 m in the multi-cylinder internal combustion engine 201 .
[0076] As has already been described in detail and thus to summarize, the connection between the collars 216 , cylinder head 201 and various cam carriers 223 m , 223 el and 223 er as well as the interengagement between the various rocker arm shafts and the fasteners maintains all of the components in their desired relationship and reduces the labor and machining to produce the engines, as described
[0077] Of course those skilled in the art will readily understand that the described embodiments are only exemplary of forms that the invention may take and that various changes and modifications may be made without departing from the spirit and scope of the invention, as defined by the appended claims.
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A number of cylinder head arrangements that provide low cost and easy assembly of their various components with minimum labor and reduced necessity for line boring to reduce both manufacturing and assembly operation without adversely affecting performance.
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BACKGROUND
[0001] The present invention relates generally to the field of business analytics, and more particularly to the use of an undo stack to explore past actions in a business analytics view.
[0002] Generally speaking, business analytics (BA) refers to the skills, technologies, and practices for continuous iterative exploration and investigation of past business performance to gain insight and drive business planning. In many cases, business analytics focuses on developing new insights and understanding of business performance based on data and statistical methods. Examples of business analytics include exploring data to discover new patterns and relationships (i.e., data mining), explaining why certain business results occurred (i.e., statistical analysis), and forecasting future business results (i.e., predictive modeling, or predictive analytics).
SUMMARY
[0003] Embodiments of the present invention disclose a method, computer program product, and system for using an undo stack to explore past actions and apply new actions to previous states in a data view. The method includes detecting a change in an application data view. The application then displays an undo stack and stores the data change in the application data view to the undo stack. Upon detecting a selection of the undo stack entry for undo, the application returns the application data view to the state represented by the undo stack entry. The method further includes providing a user interface allowing a user to perform operations on undo stack entries. Responsive to the user utilizing the user interface and making selections, the application then adjusts the application data view state based on the performed actions.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] FIG. 1 is a functional block diagram illustrating an analytics data processing environment, in an embodiment in accordance with the present invention.
[0005] FIG. 2A is a functional block diagram depicting an undo stack in a business analytics software data view, on a computer within the analytics data processing environment of FIG. 1 , after a user initializes an application, in an embodiment in accordance with the present invention.
[0006] FIG. 2B is a functional block diagram depicting the undo stack in the business analytics software data view, after a user performs a swap operation, in an embodiment in accordance with the present invention.
[0007] FIG. 2C is a functional block diagram depicting the undo stack in the business analytics software data view, after a user performs a sort operation, in an embodiment in accordance with the present invention.
[0008] FIG. 2D is a functional block diagram depicting the undo stack in the business analytics software data view, after a user performs a filter operation, in an embodiment in accordance with the present invention.
[0009] FIG. 2E is a functional block diagram depicting the undo stack in the business analytics software data view, after a user performs a keep operation, in an embodiment in accordance with the present invention.
[0010] FIG. 3A is an example business analytics software data view with an undo stack, on a computer within the analytics data processing environment of FIG. 1 , in an embodiment in accordance with the present invention.
[0011] FIG. 3B is an example business analytics software data view with an undo stack, on a computer within the analytics data processing environment of FIG. 1 , after a user selects an action to perform a “sort ascending” operation, in an embodiment in accordance with the present invention.
[0012] FIG. 3C is an example business analytics software data view with an undo stack, on a computer within the analytics data processing environment of FIG. 1 , displaying the current view after a user selects an action to perform a “hide column” operation, in an embodiment in accordance with the present invention.
[0013] FIG. 3D is an example business analytics software data view with an undo stack, on a computer within the analytics data processing environment of FIG. 1 , displaying the action taken on a previous view in the undo stack, in an embodiment in accordance with the present invention.
[0014] FIG. 3E is an example business analytics software data view with an undo stack in, on a computer within the analytics data processing environment of FIG. 1 , displaying the contents and last action of a previous view in the undo stack with available actions, in an embodiment in accordance with the present invention.
[0015] FIG. 4 is a flowchart depicting operational steps of analytics software, performing operations using an undo stack for various analytic views on a client device within the analytics data processing environment of FIG. 1 , in an embodiment in accordance with the present invention.
[0016] FIG. 5 depicts a block diagram of components of the computer executing the analytics software, in an embodiment in accordance with the present invention.
DETAILED DESCRIPTION
[0017] Embodiments in accordance with the present invention use an undo stack to explore past actions and/or apply new actions to previous states in business analytics data views. In business analytics data views, many items can be modified by the user. Working with multiple data views of an application sometimes results in users losing a data view when switching to another view. Returning back to a previous view may require the application to repopulate the view with the previous data all over again. Another drawback is that a user might not be able to see that an action has taken place on a data view once the user switches to a new view. This can be cumbersome when switching back and forth between data views is necessary for completing a task. Sometimes the change in the data view is a small number change (e.g., a single data value change) and sometimes the change is a small structure change (e.g., copy and paste of a set of data) that is applied to the data view. Transitions can be shown to users, for example by using animations, but known animations do not inform the user that a new action has been applied, and that the user can undo the applied action. There is a need in business analytics applications to have a method that combines working with an undo stack to show a user what actions have taken place and performing actions to return to past states or otherwise use past action information in helpful ways.
[0018] Embodiments in accordance with the present invention will now be described in detail with reference to the Figures. FIG. 1 is a functional block diagram, generally designated 100 , illustrating an analytics data processing environment, in an embodiment in accordance with the present invention.
[0019] Analytics data processing environment 100 includes computer 102 and servers 118 , 124 , 130 and 136 , all interconnected over network 116 . Computer 102 includes user interface (UI) 104 , random access memory (RAM) 106 , central processing unit (CPU) 108 , and persistent storage 110 . Computer 102 may be a Web server, or any other electronic device or computing system, capable of processing program instructions and receiving and sending data. In some embodiments, computer 102 may be a laptop computer, a tablet computer, a netbook computer, a personal computer (PC), a desktop computer, a personal digital assistant (PDA), a smart phone, or any programmable electronic device capable of communicating over a data connection to network 116 . In other embodiments, computer 102 may represent server computing systems utilizing multiple computers as a server system, such as in a distributed computing environment. In general, computer 102 is representative of any electronic devices or combinations of electronic devices capable of executing machine-readable program instructions and communicating with servers 118 , 124 , 130 and 136 via network 116 and with various components and devices within analytics data processing environment 100 .
[0020] Computer 102 includes user interface 104 . User interface 104 is a program that provides an interface between a user of computer 102 and a plurality of applications that reside on computer 102 (e.g., analytics software 112 ), and/or applications on computing devices that may be accessed over a data connection on network 116 . A user interface, such as user interface 104 , refers to the information (e.g., graphic, text, sound) that a program presents to a user and the control sequences the user employs to control the program. User interface 104 is a type of interface that allows users to interact with peripheral devices (i.e., external computer hardware that provides input and output for a computing device, such as a keyboard and mouse) through graphical icons and visual indicators as opposed to text-based interfaces, typed command labels, or text navigation. The actions in GUIs are often performed through direct manipulation of the graphical elements. A variety of types of user interfaces exist. In one embodiment, user interface 104 is a graphical user interface (GUI). In another embodiment, user interface 104 may be a web user interface (WUI) and can display text, documents, web browser windows, user options, application interfaces, and instructions for operation, and includes the information (such as graphic, text, and sound) that a program presents to a user and the control sequences the user employs to control the program. User interface 104 may also be mobile application software that provides an interface between a user of computer 102 and server 118 , 124 , 130 , and 136 over a data connection on network 116 . Mobile application software, or an “app,” is a computer program designed to run on smart phones, tablet computers and other mobile devices. User interface 104 enables a user of computer 102 , and analytics software 112 , to explore the undo stack to view previous actions and states, and return or apply an action to a previous state.
[0021] Computer 102 includes persistent storage 110 . Persistent storage 110 may, for example, be a hard disk drive. Alternatively, or in addition to a magnetic hard disk drive, persistent storage 110 may include a solid state hard drive, a semiconductor storage device, read-only memory (ROM), erasable programmable read-only memory (EPROM), flash memory, or any other computer-readable storage medium that is capable of storing program instructions or digital information. Analytics software 112 and analytics data 114 are stored in persistent storage 110 , which also includes operating system software, as well as software that enables computer 102 to perform one or more operations on analytics data 114 using user interface 104 , and communicate with servers 118 , 124 , 130 and 136 , as well as other computing devices of analytics data processing environment 100 over a data connection on network 116 .
[0022] Analytics software 112 is stored in persistent storage 110 and is used to view, add, edit, or delete data in analytics data 114 and/or from accounting data 122 , sales data 128 , supply data 134 , and manufacturing data 140 . Analytics software allows a user of computer 102 to save data views (with previous actions and states) on an undo stack. Analytics software 112 also allows a user to save pending actions on the saved data views of the undo stack, to be performed or modified at a later time. Analytics data 114 is also stored in persistent storage 110 and contains analytic data from accounting data 122 on server 118 , sales data 128 on server 124 , supply data 134 on server 130 , and manufacturing data 140 on server 136 .
[0023] Computer 102 may include internal and external hardware components, as depicted and described in further detail with respect to FIG. 5 .
[0024] In FIG. 1 , network 116 is shown as the interconnecting fabric between computer 102 , and servers 118 , 124 , 130 and 136 . In practice, network 116 may be any viable data transport network. Network 116 can be, for example, a local area network (LAN), a wide area network (WAN) such as the Internet, or a combination of the two, and can include wired, wireless, or fiber optic connections. In general, network 116 can be any combination of connections and protocols that will support communications between computer 102 , servers 118 , 124 , 130 and 136 in accordance with an embodiment of the invention.
[0025] Analytics data processing environment 100 includes servers 118 , 124 , 130 and 136 . In various embodiments of the present invention, servers 118 , 124 , 130 and 136 can each respectively be a laptop computer, tablet computer, netbook computer, personal computer (PC), a desktop computer, a personal digital assistant (PDA), a smart phone, or any programmable electronic device capable of communicating with computer 102 via network 116 . In the example embodiment of FIG. 1 , servers 118 , 124 , 130 and 136 each include persistent storage. For example, server 118 includes persistent storage 120 , server 124 includes persistent storage 126 , server 130 includes persistent storage 132 , and server 136 includes persistent storage 138 .
[0026] Persistent storage 120 , 126 , 132 , and 138 may, for example, be hard disk drives. Alternatively, or in addition to a magnetic hard disk drive, persistent storage 120 , 126 , 132 , and 138 may include solid state hard drives, semiconductor storage devices, read-only memory (ROM), erasable programmable read-only memory (EPROM), flash memory, or any other computer-readable storage medium that are capable of storing program instructions or digital information. Persistent storage 120 , 126 , 132 , and 138 also contain operating system software, as well as software that enables server 118 , 124 , 130 , and 136 to communicate with computer 102 , as well as other computing devices of analytics data processing environment 100 over a data connection on network 116 .
[0027] Persistent storage 120 includes accounting data 122 that is used by analytics software 112 and other computing devices (not shown) of analytics data processing environment 100 . Persistent storage 126 includes sales data 128 that is used by analytics software 112 and other computing devices (not shown) of analytics data processing environment 100 . Persistent storage 132 includes supply data 134 that is used by analytics software 112 and other computing devices (not shown) of analytics data processing environment 100 . Persistent storage 138 includes manufacturing data 140 that is used by analytics software 112 and other computing devices (not shown) of analytics data processing environment 100 .
[0028] FIG. 2A is a functional block diagram depicting an undo stack in a business analytics software data view, on a computer within the analytics data processing environment of FIG. 1 , after a user initializes an application, in an embodiment in accordance with the present invention. In an example embodiment, a user of analytics software 112 opens a saved business analytics software data file that results in the initial data view being added to undo stack 202 . The resulting undo stack 202 displays the initial application state 208 as the new current state 210 with undo action 204 and redo action 206 as depicted in FIG. 2A . Initial application state 208 represents the initial state of the application, before any actions have been performed, and current state 210 includes an arrow indicating that initial application state 208 is the current state of the analytics software data view. Undo action 204 allows a user of analytics software 112 to undo a previous action, or revert/adjust to a previous state, in the selected data view. Redo action 206 allows a user of analytics software 112 to re-apply an action or retrieve a state that had an undo action performed on it. In one example embodiment, the undo stack is displayed as a horizontal slide bar on user interface 104 , as depicted in FIG. 2A , where the user actions or operations slide into the undo stack from the right. As more operations are performed by the user, the previous operations on the stack slide to the left as the current action in the current view is added. In other example embodiments, the undo stack may be displayed as a vertical slide bar on the left or right side of user interface 104 .
[0029] FIG. 2B is a functional block diagram depicting the undo stack in the business analytics software data view, after a user performs a swap operation, in an embodiment in accordance with the present invention. In an example embodiment, a user of analytics software 112 performs a swap operation in a business analytics software data view that results in the swap operation being added to undo stack 202 . The resulting undo stack 202 displays initial application state 208 , previous action 212 (which represents the swap operation), and state 214 (which represents, or is associated with, the data view after the swap operation) as the current state 210 , as depicted in FIG. 2B . Previous action 212 and state 214 slide in from the right side of undo stack 202 , resulting in initial application state 208 moving to the left. Previous action 212 , in addition to representing (or “containing”) the swap operation, may also contain other previous operations of initial application state 208 . An example of this, using FIG. 2B , would be a user clicking on state 208 and saving the stored state of the initial application to use at a later time or send to a colleague. The previous action may include a drop-down menu context or a pop-up window, displaying the previous operations or states of the data view. In one example embodiment, the user of analytics software 112 may be asked to verify adding the current view to undo stack 202 prior to performing the operation (for example, the swap operation). In another example embodiment, previous action 212 may also be used to queue up pending actions to the saved data views, to be applied at a later time. Drop-down contexts and pop-up windows relating to undo stack 202 are described in further detail with respect to FIG. 3D and 3E .
[0030] FIG. 2C is a functional block diagram depicting the undo stack in the business analytics software data view, after a user performs a sort operation, in an embodiment in accordance with the present invention. In an example embodiment, a user of analytics software 112 performs a sort operation in a business analytics software data view that results in the sort operation being added to undo stack 202 . The resulting undo stack 202 displays initial application in state 208 with previous action 212 , state 214 , previous action 216 (which represents the sort operation), and state 218 (which represents the data view after the sort operation) in current state 210 , as depicted in FIG. 2C . Previous action 216 and state 218 slide in from the right side of undo stack 202 , resulting in initial application in state 208 , previous action 212 , and state 214 moving to the left. Previous action 216 , in addition to representing (or “containing”) the sort operation, may also contain other previous operations of state 214 . In another example embodiment, the user of analytics software 112 may configure analytics software 112 , using user interface 104 , prior to performing actions, to add only certain views, operations, and states to undo stack 202 . In another example embodiment, analytics software 112 may be able to flag a moment in time using undo stack 202 to indicate when and where analytics data 114 indicates an upward or downward trend.
[0031] FIG. 2D is a functional block diagram depicting the undo stack in the business analytics software data view, after a user performs a filter operation, in an embodiment in accordance with the present invention. In an example embodiment, a user of analytics software 112 performs a filter operation in a business analytics software data view that results in the filter operation being added to undo stack 202 . The resulting undo stack 202 displays initial application in state 208 with previous action 212 , state 214 , previous action 216 , state 218 , previous action 220 (which represents the filter operation), and state 222 (which represents the data view after the filter operation) in current state 210 , as depicted in FIG. 2D . Previous action 220 and state 222 slide in from the right side of undo stack 202 , resulting in initial application in state 208 , previous action 212 , state 214 , previous action 216 , and state 218 moving to the left. Previous action 220 , in addition to representing (or “containing”) the filter operation, may also contain other previous actions of state 218 . In another example embodiment, the undo stack created by analytics software 112 may be saved to continue working at a later time by a user of computer 102 . In other example embodiments, analytics software 112 may be able to freeze (e.g., protect data to prevent changes from occurring), in saved data views of undo stack 202 .
[0032] FIG. 2E is a functional block diagram depicting the undo stack in the business analytics software data view, after a user performs a keep operation, in an embodiment in accordance with the present invention. In an example embodiment, a user of analytics software 112 performs a keep operation in a business analytics software data view that results in the keep operation being added to undo stack 202 . The resulting undo stack 202 displays initial application in state 208 with previous action 212 , state 214 , previous action 216 , state 218 , previous action 220 , and state 222 , previous action 224 (which represents the keep operation), and state 226 (which represents the data view after the keep operation) in current state 210 as depicted in FIG. 2E . Previous action 224 and state 226 slide in from the right side of undo stack 202 , resulting in initial application in state 208 , previous action 212 , state 214 , previous action 216 , state 218 , previous action 220 , state 222 , and previous action 224 moving to the left. Previous action 224 , in addition to representing (or “containing”) the keep operation, is used to contain the previous actions and/or states of state 222 . In another example embodiment, the undo stack created by analytics software 112 may be saved and exported to other computing devices (not shown) of analytics data processing environment 100 . In other example embodiments, analytics software 112 may use undo stack 202 to create macros to manipulate, perform calculations, or projections on analytics data 114 and/or accounting data 122 , and/or sales data 128 , and/or supply data 134 , and/or manufacturing data 140 .
[0033] FIG. 3A is an example business analytics software data view with an undo stack, on a computer within the analytics data processing environment of FIG. 1 , in an embodiment in accordance with the present invention. In an example embodiment, a user opens a data file using analytics software 12 , to view, update, and/or delete business analytics data (e.g., analytics data 114 ) from one or more repositories (e.g., accounting data 122 on server 118 , sales data 128 on server 124 , supply data 134 on server 130 , and manufacturing data 140 on server 136 ). Analytics software 112 opens the data file and populates user interface 104 with the saved data as shown in application view 320 and depicted in FIG. 3A . Application view 320 contains undo stack 302 with state 308 as the current state 310 . State 308 represents the initial state of the application, before any actions have been performed, and current state 310 includes an arrow indicating that initial application state 308 is the current state of the analytics software data view. Application view 320 includes a cross table with data column “2004” 322 , data column “Q1-2004” 324 , data column “Jan-2004” 326 , data column “Feb-2004” 328 , and data column “Mar-2004” 330 . Undo stack 302 contains undo action 304 and redo action 306 to undo or redo previous actions. A cross table is a two-way table, also referred to as a pivot table or a multi-dimensional table, consisting of columns and rows where data is rendered based on results of queries on one or more databases (e.g., accounting data 122 , sales data 128 , supply data 134 , and manufacturing data 140 ). Its greatest strength is its ability to structure, summarize and display large amounts of data. In other example embodiments, undo action 304 and redo action 306 may both be greyed out, or not be selectable, by a user until an action or operation is performed and stored in undo stack 302 .
[0034] FIG. 3B is an example business analytics software data view with an undo stack, on a computer within the analytics data processing environment of FIG. 1 , after a user selects an action, or entry, to perform a “sort ascending” operation, in an embodiment in accordance with the present invention. In an example embodiment, a user performs a “sort ascending” operation on application view 320 to arrange the data contained in data column “2004” 322 , data column “Q1-2004” 324 , data column “Jan-2004” 326 , data column “Feb-2004” 328 , and data column “Mar-2004” 330 from lowest to highest. In other example embodiments, a user may sort the data contained in application view alphabetically, or by date. In general, analytics software 112 and application view 320 may perform any programmable computing operation on computer 102 or a computing device of analytics data processing environment 100 .
[0035] The resulting undo stack 302 displays the initial application state 308 , previous action 312 (which represents the “sort ascending” operation), and state 314 (which represents the data view after the “sort ascending” operation) as the current state 310 , as depicted in FIG. 3B . Previous action 312 and state 314 slide in from the right side of undo stack 302 , resulting in the initial application state 308 moving to the left. Previous action 312 , in addition to representing (or “containing”) the “sort ascending” operation, may also contain other previous operations of initial application state 308 . Undo action 304 would allow the user to adjust application view 320 back to the original data view in state 308 . Redo action 306 would be greyed our, or not selectable by the user in current data view 324 . Application view 320 in current state 310 now shows the data contained in data column “2004” 322 , data column “Q1-2004” 324 , data column “Jan-2004” 326 , data column “Feb-2004” 328 , and data column “Mar-2004” 330 arranged from lowest to highest. In one example embodiment, a user of computer 102 may use voice commands to perform operations using analytics software 112 .
[0036] FIG. 3C is an example business analytics software data view with an undo stack, on a computer within the analytics data processing environment of FIG. 1 , displaying the current view after a user selects an action to perform a “hide column” operation in an embodiment in accordance with the present invention. In an example embodiment, a user performs a “hide column” operation on application view 320 to hide column “Q1-2004” 324 from view on application view 320 . The resulting undo stack 302 displays the initial application state 308 , previous action 312 , state 314 , previous action 316 (which represents the “hide column” operation), state 318 (which represents the data view after the “hide column” operation) in current state 310 , undo action 304 , and redo action 306 as depicted in FIG. 3C . Previous action 316 and state 318 slide in from the right side of undo stack 202 , resulting in initial application in state 308 , previous action 312 , and state 314 moving to the left. Previous action 316 , in addition to representing (or “containing”) the “hide column” operation, may also contain other previous operations of state 314 . Application view 320 in current state 310 now shows the data contained in data column “2004” 322 , data column “Jan-2004” 326 , data column “Feb-2004” 328 , and data column “Mar-2004” 330 arranged from lowest to highest, and data column “Q1-2004” 324 no longer visible. Undo action 304 would allow the user to revert application view 320 back to the previous state 314 when the user performed the “hide column” operation. Redo action 306 would be greyed out, or not selectable by the user in current state 310 unless undo action 304 was performed. In other example embodiments, analytics software 112 may automatically save, or write to persistent storage 110 , all updates to undo stack 302 , where the updates include all actions performed on the data view, and data states.
[0037] FIG. 3D is an example business analytics software data view with an undo stack, on a computer within the analytics data processing environment of FIG. 1 , displaying the action taken on a previous view in the undo stack, in an embodiment in accordance with the present invention. In an example embodiment, a user clicks on, or hovers over, previous action 312 to view the previous action that was performed by the user on application view 320 for state 308 . Undo stack 302 displays the initial application state 308 , previous action 312 , state 314 , previous action 316 , state 318 in current state 310 , undo action 304 , and redo action 306 as depicted in FIG. 3D . Analytics software 112 provides the user with drop-down menu 332 , also referred to as a pop-up window menu (or a “drop-down”), displaying the previous operation (e.g., “sort ascending”) that was performed on state 308 . Drop-down 332 is labeled “Action” and contains the previous action “sort ascending” that was performed on state 308 . Drop-down 332 is an example UI drop-down. In general, any programmed graphical user interface menu may be used to display the information in drop-down 332 .
[0038] FIG. 3E is an example business analytics software data view with an undo stack, on a computer within the analytics data processing environment of FIG. 1 , displaying the contents and last action of a previous view in the undo stack with available actions, in an embodiment in accordance with the present invention. In an example embodiment, a user clicks on, or hovers over, state 314 to display a summary of the previous data view and the previous action that was performed by the user on application view 320 . Undo stack 302 displays the initial application state 308 , previous action 312 , state 314 , previous action 316 , state 318 in current state 310 , undo action 304 , and redo action 306 as depicted in FIG. 3E . Analytics software 112 provides the user with a drop-down menu 334 , also referred to as a pop-up window menu (or a “drop-down”), labeled “Data Content” that displays a summary of the previous data view (e.g., the original data from state 314 ) and the last action that was performed.
[0039] Drop-down 334 also contains clickable push buttons labeled “Return here” 338 , “Apply to storyline” 340 , and “Save” 342 . The “Return here” 338 push button allows the user to return application view 320 to the previous state of state 314 . Upon selecting “Return here” 338 by the user, analytics software 112 reverts application view 320 back to state 314 and results in state 314 being the current state 310 . The “Apply to storyline” 340 push button enables a user of analytics software to add the selected data view to a presentation, or import the selected data view to another spreadsheet, or add the selected data view to an infographic. An infographic, also referred to as an information graphic, is a graphic visual representation of information, data or knowledge intended to present information quickly and clearly. The “Save” 342 push button enables the user of analytics software 112 to save the selected data view to an undo stack file for sharing with other computing devices in analytics data processing environment 100 , and/or for later editing, updating, or viewing. In general, analytics software 112 may detect and respond to any programmable UI element in application data view 320 and undo stack 302 .
[0040] FIG. 4 is a flowchart, generally designated 400 , depicting operational steps of an analytics software, performing operations using an undo stack for various analytic views on a client device within the analytics data processing environment of FIG. 1 , in an embodiment in accordance with the present invention. A user of analytics software 112 , on computer 102 , opens an initial data view for analytics data 114 and/or analytics data on server 118 , 124 , 130 , and/or 136 (e.g., accounting data 122 , sales data 128 , supply data 134 , and manufacturing data 140 ), as depicted in step 402 . In one example embodiment, analytics data may open with a saved undo stack. A user may click on a file, with the use of user interface 104 , and the operating system of computer 102 , based on the file extension, launches or begins execution of analytics software 112 and populates the saved undo stack in the data view once analytics data 114 is loaded.
[0041] In step 404 , a user performs an action on a view using user interface 104 and analytics software 112 . Examples of actions that may be performed include, but are not limited to, an expand operation, a swap operation, a sort operation, a filter operation, a keep operation, a select operation, a store operation, a flag operation, a branch operation, an access operation, restructuring the data view by moving content from the rows to the columns and vice versa, changing filters that apply to the data cells of the view, hiding values, filtering values, adding data, expanding or collapsing data values, drill down or drill up on values, spread data values, applying various formats to data values, and showing totals as trailing or leading. In one example embodiment, the user performs an expand operation of a range of data stored in analytics data 114 . Analytics software 112 populates user interface 104 with the specified data from analytics data 114 and/or accounting data 122 , and/or sales data 128 , and/or supply data 134 , and/or manufacturing data 140 .
[0042] Analytics software 112 updates the view on user interface 104 and adds, or slides in, the expand operation to the undo stack and places the expand operation in the current view as illustrated in FIG. 2A and depicted in step 406 . If there are previous operations on the undo stack, analytics software 112 inserts a previous action between the two operations as depicted by previous action 212 in FIG. 2B . In other example embodiments, a user may schedule actions to be performed by analytics software 112 by creating an undo stack with operations and desired states to be carried out by analytics software 112 at a specified time.
[0043] In decision step 408 , analytics software 112 checks if the user has performed another action on the current view. If a new action has been performed for the current view (“Yes” branch, decision 408 ), analytics software 112 populates user interface 104 with the new data and repeats steps 404 and 406 for any actions or operations the user makes on the current view. In other example embodiments, analytics software 112 may display multiple views on user interface 104 , or across multiple display monitors attached to computer 102 .
[0044] If there are no more actions on the current view (“No” branch, decision 408 ), analytics software 112 checks if the user has switched to another view as depicted in decision step 410 . If the user has switched to a new view (“Yes” branch, decision 410 ), analytics software 112 repeats steps 402 through 408 . In other example embodiments, analytics software 112 may use, or load, undo stacks of previous actions (i.e., from saved histories or saved undo stacks), when switching views. A user may be presented with the option, using user interface 104 , to select saved undo stacks, or previous actions within the saved undo stacks, to use when initializing the data view. In another example embodiment, analytics software 112 may allow a user to select several undo stacks, and turn the previous actions and saved states of the undo stacks into a movie showing all the previous saved actions and states of the undo stacks in a step-by-step animation.
[0045] If the user has not switched to a new view (“No” branch, decision 410 ), analytics software 112 waits until the user selects a previous view as depicted in step 412 . In one example embodiment, a user invokes, or performs, a branch operation on a previous view as depicted in step 414 and/or a user invokes, or performs, a copy operation on a previous view as depicted in step 416 , and/or a user invokes, or performs, a “save as” operation on a previous view as depicted in step 418 . If the user invokes, or performs, a copy operation, analytics software 112 creates a new window with the selected view and the undo stack attached as depicted in step 420 . In other example embodiments, analytics software 112 may open the new data view in a new tabbed document interface (TDI), also referred to as a tab, within the existing window. In interface design, a tabbed document interface refers to a graphical control element that allows multiple documents or panels to be contained within a single window, using tabs as a navigational widget for switching between sets of documents or views. In step 422 , analytics software brings the new view and undo stack of the new instance for the user. The new data view is displayed, along with the undo stack, for the user to view and/or perform operations on.
[0046] If a user invokes, or performs, a copy operation on a previous view as depicted in step 416 , analytics software 112 copies the data and the undo stack in the selected view, then makes the selected view available for reuse. Using FIG. 2D as an example, the user selects state 214 , and selects copy. Analytics software 112 then copies the data and the undo stack in selected state 214 together with previous action 212 and makes selected view 214 available for reuse as depicted in step 424 . Analytics software 112 then brings the view and undo stack back to the current view 210 as depicted in step 426 . In one example embodiment, the previous actions, when selected, may provide the user with a drop-down menu displaying the previous operations and states of the data view. In another example embodiment, the previous actions, when selected, may provide the user with a pop-up window menu displaying the previous operations and states of the data view.
[0047] If a user invokes, or performs, a “save as” operation on a previous view as depicted in step 418 , analytics software 112 provides a user with a drop-down, or pop-up window context asking the user to input a file name for the undo stack. In one example embodiment, analytics software 112 automatically generates a filename and displays the filename for the user to modify if needed. Analytics software 112 then saves the selected view and undo stack and applies any pending actions the user may not have applied to the view as depicted in step 428 . The user and system remain in the current view throughout the performed “save as” operation by analytics software 112 as depicted in step 430 .
[0048] FIG. 5 depicts a block diagram, generally designated 500 , of components of the computer executing the analytics software, in an embodiment in accordance with the present invention. It should be appreciated that FIG. 5 provides only an illustration of one implementation and does not imply any limitations with regard to the environments in which different embodiments may be implemented. Many modifications to the depicted environment may be made.
[0049] Computer 102 includes communications fabric 502 , which provides communications between computer processor(s) 504 , memory 506 , persistent storage 508 , communications unit 510 , and input/output (I/O) interface(s) 512 . Communications fabric 502 can be implemented with any architecture designed for passing data and/or control information between processors (such as microprocessors, communications and network processors, etc.), system memory, peripheral devices, and any other hardware components within a system. For example, communications fabric 502 can be implemented with one or more buses.
[0050] Memory 506 and persistent storage 508 are computer readable storage media. In this embodiment, memory 506 includes random access memory (RAM) 514 and cache memory 516 . In general, memory 506 can include any suitable volatile or non-volatile computer readable storage media.
[0051] Analytics software 112 and analytics data 114 are stored in persistent storage 508 for execution and/or access by one or more of the respective computer processors 504 via one or more memories of memory 506 . In this embodiment, persistent storage 508 includes a magnetic hard disk drive. Alternatively, or in addition to a magnetic hard disk drive, persistent storage 508 can include a solid state hard drive, a semiconductor storage device, read-only memory (ROM), erasable programmable read-only memory (EPROM), flash memory, or any other computer readable storage media that is capable of storing program instructions or digital information.
[0052] The media used by persistent storage 508 may also be removable. For example, a removable hard drive may be used for persistent storage 508 . Other examples include optical and magnetic disks, thumb drives, and smart cards that are inserted into a drive for transfer onto another computer readable storage medium that is also part of persistent storage 508 .
[0053] Communications unit 510 , in these examples, provides for communications with other data processing systems or devices, including resources of network 116 and server 118 , 124 , 130 , and 136 . In these examples, communications unit 510 includes one or more network interface cards. Communications unit 510 may provide communications through the use of either or both physical and wireless communications links. Analytics software 112 and analytics data 114 may be downloaded to persistent storage 508 through communications unit 510 .
[0054] I/O interface(s) 512 allows for input and output of data with other devices that may be connected to computer 102 . For example, I/O interface 512 may provide a connection to external devices 518 such as a keyboard, keypad, a touch screen, and/or some other suitable input device. External devices 518 can also include portable computer readable storage media such as, for example, thumb drives, portable optical or magnetic disks, and memory cards. Software and data used to practice embodiments of the present invention, e.g., analytics software 112 and analytics data 114 , can be stored on such portable computer readable storage media and can be loaded onto persistent storage 508 via I/O interface(s) 512 . I/O interface(s) 512 also connect to a display 520 .
[0055] Display 520 provides a mechanism to display data to a user and may be, for example, a computer monitor.
[0056] The programs described herein are identified based upon the application for which they are implemented in a specific embodiment of the invention. However, it should be appreciated that any particular program nomenclature herein is used merely for convenience, and thus the invention should not be limited to use solely in any specific application identified and/or implied by such nomenclature.
[0057] The present invention may be a system, a method, and/or a computer program product. The computer program product may include a computer readable storage medium (or media) having computer readable program instructions thereon for causing a processor to carry out aspects of the present invention.
[0058] The computer readable storage medium can be a tangible device that can retain and store instructions for use by an instruction execution device. The computer readable storage medium may be, for example, but is not limited to, an electronic storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination of the foregoing. A non-exhaustive list of more specific examples of the computer readable storage medium includes the following: a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), a static random access memory (SRAM), a portable compact disc read-only memory (CD-ROM), a digital versatile disk (DVD), a memory stick, a floppy disk, a mechanically encoded device such as punch-cards or raised structures in a groove having instructions recorded thereon, and any suitable combination of the foregoing. A computer readable storage medium, as used herein, is not to be construed as being transitory signals per se, such as radio waves or other freely propagating electromagnetic waves, electromagnetic waves propagating through a waveguide or other transmission media (e.g., light pulses passing through a fiber-optic cable), or electrical signals transmitted through a wire.
[0059] Computer readable program instructions described herein can be downloaded to respective computing/processing devices from a computer readable storage medium or to an external computer or external storage device via a network, for example, the Internet, a local area network, a wide area network and/or a wireless network. The network may comprise copper transmission cables, optical transmission fibers, wireless transmission, routers, firewalls, switches, gateway computers and/or edge servers. A network adapter card or network interface in each computing/processing device receives computer readable program instructions from the network and forwards the computer readable program instructions for storage in a computer readable storage medium within the respective computing/processing device.
[0060] Computer readable program instructions for carrying out operations of the present invention may be assembler instructions, instruction-set-architecture (ISA) instructions, machine instructions, machine dependent instructions, microcode, firmware instructions, state-setting data, or either source code or object code written in any combination of one or more programming languages, including an object oriented programming language such as Smalltalk, C++ or the like, and conventional procedural programming languages, such as the “C” programming language or similar programming languages. The computer readable program instructions 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). In some embodiments, electronic circuitry including, for example, programmable logic circuitry, field-programmable gate arrays (FPGA), or programmable logic arrays (PLA) may execute the computer readable program instructions by utilizing state information of the computer readable program instructions to personalize the electronic circuitry, in order to perform aspects of the present invention.
[0061] Aspects of the present invention are described herein with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer readable program instructions.
[0062] These computer readable program instructions may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks. These computer readable program instructions may also be stored in a computer readable storage medium that can direct a computer, a programmable data processing apparatus, and/or other devices to function in a particular manner, such that the computer readable storage medium having instructions stored therein comprises an article of manufacture including instructions which implement aspects of the function/act specified in the flowchart and/or block diagram block or blocks.
[0063] The computer readable program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other device to cause a series of operational steps to be performed on the computer, other programmable apparatus or other device to produce a computer implemented process, such that the instructions which execute on the computer, other programmable apparatus, or other device implement the functions/acts specified in the flowchart and/or block diagram block or blocks.
[0064] The flowchart and block diagrams in the Figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of the present invention. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of instructions, which comprises one or more executable instructions for implementing the specified logical function(s). In some alternative implementations, the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware-based systems that perform the specified functions or acts or carry out combinations of special purpose hardware and computer instructions.
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A computer system for using an undo stack to explore past actions and apply new actions to previous states in a data view is provided. The computer system includes program instructions to detect a change in an application data view. The application then displays an undo stack and stores the data change in the application data view to the undo stack. Upon detecting a selection of the undo stack entry for undo, the application returns the application data view to the state represented by the undo stack entry. The computer system further includes program instructions to provide a user interface allowing a user to perform operations on undo stack entries. Responsive to the user utilizing the user interface and making selections, the application then adjusts the application data view state based on the performed actions.
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The invention relates to the preparation of polypropylene composites using natural reinforcements from eggshells obtained as agroindustrial wastes, and it includes the process to obtain such composites, the natural eggshell reinforcement, and the process to obtain such reinforcement. This invention makes it possible to obtain polypropylene composites using natural reinforcements that have improved mechanical and thermal behavior when compared to the polypropylene composites using traditional mineral reinforcements. The composites of the invention can be used in all the technical fields that require such composites, such as the automotive, electronics, packaging and textile fields, among other fields in which they may be applicable according to the properties of the composite.
FIELD OF THE INVENTION
At present, the manufacture of composites made with thermoplastic and semicrystalline polymers such as polypropylene satisfies the demand for new materials and their incorporation into the requirements of new technologies.
Composites are polymer based materials that incorporate an additional component, a reinforcement in the polymer matrix, in such a way as to improve the properties of the composites. Most commonly, calcium carbonate or talc are used as reinforcements.
Polypropylene, the main raw material of the composites of this invention, has good resistance and ductility at a temperature of 20-25° C. and at moderate rates of deformation. However, it is brittle at temperatures below 0° C. and at high stress rates, thereby causing a rapid transition from ductile to fragile.
Due to this deficient behavior under extreme conditions, there is commercial and scientific interest in overcoming this disadvantage by modifying some properties, such as optimizing stiffness, impact resistance, homogeneous microstructure and degree of crystallinity by manufacturing new composites based on polypropylene at low production cost.
The applications of these composites are very extensive and are undergoing constant development. Depending on the degree of optimization of the composite properties it will be possible to include new fields of use and thus replace traditional materials. At present, polypropylene composites with reinforcements find use mainly in the automotive, electronic, packaging and textile industry, among others.
BACKGROUND OF THE INVENTION
The purpose of adding mineral reinforcements to polymers in order to obtain different composites has been mainly to fulfill a functional requirement such as increasing stiffness or reducing manufacturing costs.
The reinforcements used in polypropylene composites have usually been talc and calcium carbonate of mineral origin, and to a smaller extent mica and fibers. Usually, the addition of mineral reinforcements has an effect on the fragility of the polymer composite and decreases the impact energy. Therefore, the addition of rigid particles to polypropylene leads to a loss of flexibility in the polymer.
Alternatives for the development of polypropylene composites having better stiffness, impact resistance and crystallinity can be obtained by chemically modifying the polymer (which implies changing the molecular structure by the incorporation of functional groups or molecules in the polymerization process or by an insertion reaction additional to polymerization) as well as by the type of reinforcement used.
Polypropylene composites may be obtained by the use of resistant reinforcements such as fibers and/or by the incorporation of reinforcements of submicrometer particle size to reduce the plastic resistance of the composite.
In the manufacture process of a polypropylene composite, the molecular weight range or the melt flow index of polypropylene must be considered, as well as the homogeneous distribution of the reinforcement in the polymer matrix, in such a way that the maximum compatibility is achieved between the hydrophilic reinforcement and the hydrophobic matrix. Maximum interfacial adhesion must also be achieved between the reinforcement and the polymer matrix to optimize the mechanical and thermal properties of the composite. Usually this compatibility between the reinforcement and the polymer matrix can be improved by using polypropylenes that have different melt flow indices as well as by using reinforcements that have submicrometer particle size with a narrow particle size distribution.
The most commonly used reinforcements in polypropylene composites are calcium carbonate or talc, both having mineral origin, and it is possible to obtain polypropylene composites by mixing in an extrusion molding process. Polypropylene composites with these mineral reinforcements have better mechanical behavior than polypropylene alone. When a mineral material or chemical compound such as calcium carbonate or talc is incorporated, the cost decreases because of the lower use of polypropylene in the composite. With this invention, however, the production cost of polypropylene composites has been optimized, since a waste material, eggshells, is used as reinforcement.
Egg processing plants around the world use billions of eggs every year, depositing thousands of tons of eggshells in dump sites. In Chile 2,500 million eggs are produced per year, of which about 10% are meant for industrial use. This implies that annual industrial eggshell waste is in the order of 1,500 tons.
No information has been found in the state of the art on polypropylene composites with eggshell reinforcement, nor on the use of eggshells to obtain a natural reinforcement as shown in this invention.
The manufacture of polypropylene composites using eggshell reinforcement developed in this invention has the following advantages when compared to polypropylene composites using traditional and commercial natural reinforcements like calcium carbonate or talc:
The composites of this invention combine the properties of the polymer matrix and the advantages of using an agroindustrial waste such as eggshells to obtain a natural type of reinforcement that has availability, recyclability, efficient use of energy, environmental benefits, and low cost. The composite of the invention has a higher Young's modulus, which means greater stiffness, than the polypropylene composite using a calcium carbonate reinforcement with the smallest commercially available average particle size (d(50)=0.50 μm). The composites of this invention have lower density, greater crystallinity and better mechanical behavior to traction and impact than polypropylene composites using calcium carbonate. The natural reinforcement makes it possible to replace up to 75% by weight of total talc with the natural reinforcement in polypropylene composites, yet retaining the high stiffness of composites using submicrometer talc with an average particle size d(50)=0.50 μm. Thus, less talc is used as reinforcement in the polypropylene composite and the density of the composite decreases by up to 10% at the same time. There is high compatibility and good adhesion between the natural reinforcement and polypropylene using polypropylenes that have different melt flow indices. Lower rate of decrease of the energy absorbed on impact as the proportion of reinforcement in the polypropylene composite increases, compared with traditional reinforcements.
In addition, the natural reinforcement used to obtain polypropylene composites according to this invention has the following advantages with respect to traditional commercial mineral reinforcements such as calcium carbonate and talc:
A chemical composition whose main component, calcium carbonate, corresponds to one of the traditional mineral reinforcements most widely used in polypropylene composites. A calcite crystallographic structure like that of mineral calcium carbonate. Its average particle size is in the submicrometer range and it has a narrow particle size distribution, appropriate for use as reinforcement in a polypropylene matrix. The morphology of its particles is laminar and therefore it allows better orientation in the polypropylene matrix. Lower density than the traditional mineral reinforcements such as calcium carbonate and talc used as reinforcements in polypropylene. Lower cost than the traditional mineral reinforcements used in polypropylene composites. No technological use that may give it an added value: it is just an agroindustrial waste without further usefulness.
SUMMARY OF THE INVENTION
In this invention a procedure has been developed to obtain novel polypropylene composites with a reinforcement having natural origin like eggshells, thus obtaining composites that are competitive with respect to those composites using traditional mineral reinforcements.
These polypropylene composites with natural reinforcement have improved mechanical, thermal and structural behaviors when compared to those of polypropylene composites with traditionally used mineral reinforcements. This refers mainly to improved stiffness and impact resistance, as well as to the degree of crystallinity and the distribution and adhesion of the reinforcement particles in the polymer matrix, which are advantages with respect to polypropylene composites using mineral reinforcements such as calcium carbonate or talc. Moreover, the polypropylene composites with natural reinforcement developed in this invention give added value to a waste material of the poultry industry, namely eggshells, an abundant and recyclable biological waste.
Specifically, the invention relates to polypropylene composites with a natural reinforcement, the natural reinforcement obtained from eggshells, the procedure to (1) prepare the natural reinforcement from the agroindustrial waste in the form of eggshells, and (2) the procedure to prepare the semicrystalline polypropylene homopolymer composite with the natural reinforcement.
The natural reinforcement is produced from eggshells by crushing and grinding the eggshells together with the membrane that is attached to the calcareous wall. The grinding of the eggshells produces a material smaller than ASTM 400 mesh. This ground material is used as reinforcement to obtain polypropylene composites having different melt flow indices.
The process of manufacturing the composite using the natural reinforcement includes dosing and mixing the composite components—polypropylene, an antioxidant and the dry natural reinforcement—in a stream of an inert gas like nitrogen, argon or helium, among others; pressing the material obtained from the mixing step; and finally granulating the pressed material.
DETAILED DESCRIPTION OF THE INVENTION
The procedure to obtain polypropylene composites using natural reinforcements according to the invention comprises the following steps:
a) Sequential dosing of a polypropylene homopolymer, an antioxidant and the dry natural reinforcement in a discontinuous mixer. b) Mixing at 70-75 rpm the mixture obtained in step (a) at 190-195° C. during 10-15 minutes in a stream of an inert gas such as gaseous nitrogen. c) Pressing the mass obtained from the mixing step at 40-50 bar and 30-40° C. d) Triturating the pressed material.
Step (a), dosing the composite components, includes adding between 10% and 60% by weight of natural reinforcement to the polypropylene homopolymers, and involves adding an antioxidant such as, for example, Irganox 1010® and Irgafos 168® supplied by Petroquim S.A., in a 2:1 ratio, corresponding to 0.2-0.3% by weight of the total mass of composite. This antioxidant prevents the degradation of polypropylene during the mixing process.
Step (b) is carried out in a discontinuous mixer. Mixing the composite components, polypropylene, antioxidant and natural reinforcement, has the purpose of distributing homogeneously the natural reinforcement in the half-molten polypropylene matrix. Once all the composite components have been added, mixing is continued during 10-15 minutes in a stream of inert gas like nitrogen, for example, whose function is to displace the oxidizing air environment in the chamber and prevent the degradation of polypropylene.
The mass obtained in step (b) is pressed at 40-60 bar and 30-40° C. to obtain pressed plates 1-2 mm thick that finally go to step (d), which involves granulation of the resulting plates.
Step (d), granulation of the plates, is carried out by manual or mechanical cutting into rectangular pieces approximately 1-3 mm long and wide.
The granular material corresponds to the composite of the invention, having a composition according to the selected dosing of the natural reinforcement obtained from eggshells, which may be in the range of 10-60% by weight.
From this granulated composite test specimens sized according to ASTM standards were obtained in order to determine their mechanical tensile properties (ASTM standard D 638), Izod impact testing (ASTM standard D 256) and density (ASTM standard 792), as well as to perform the corresponding thermal tests for these composites.
The procedure described in this invention to obtain polypropylene composites using natural reinforcement from eggshells involves having this natural reinforcement available under conditions suitable for dosing and mixing it with polypropylene. In order to achieve this objective, this invention also comprises the procedure to manufacture the natural reinforcement using the eggshells obtained from agroindustrial wastes.
Procedure to Obtain the Natural Reinforcement from Eggshells
The procedure to obtain the natural reinforcement from eggshells comprises the following steps:
a) crushing and sifting the agroindustrial material below ASTM 100 mesh; b) drying at 100-110° C. during 8-9 hours; and c) mechanical grinding and sifting the product obtained in step (b) to get particles below ASTM 400 mesh.
The crushing step (a) of the eggshells consists in obtaining the material having a homogeneous particle size by means of a manual or mechanical procedure to obtain particles below ASTM 100 mesh.
The manual crushing procedure may be carried out, for example, using a porcelain mortar to break up the material down to the required size below ASTM 100 mesh.
The mechanical crushing procedure may be carried out using any appropriate equipment for that function, for example, a mechanical device with flat metallic blades or cutters, and one skilled in the art may be able to use any equipment that will allow getting the material below ASTM 100 mesh in a shorter time and processing a larger amount of material as may be required.
The eggshells crushed to a particle size below ASTM 100 mesh is dried in an oven that allows the temperature to be kept between 100 and 110° C. during 8 to 9 hours (step b). This procedure to optimize the grinding process is a necessary requirement to optimize the grinding process in the following step in order to obtain the natural reinforcement.
The grinding of the dry natural reinforcement (step c) below ASTM 100 mesh is carried out by means of any appropriate device, such as a concentric metal ring mill or a metal ball mill. The time required for grinding depends on the capacity of the device used for grinding. For example, in a metal ring mill with a maximum volume capacity of 0.5 liters, 150-190 grams of dry natural reinforcement below ASTM 100 mesh can be ground in about 10-12 minutes.
The material resulting from this grinding operation is sifted through an ASTM 400 mesh sieve, and the submicrometer natural reinforcement below ASTM 400 mesh is obtained with a yield between 90 and 95% by weight of the processed agroindustrial material.
EXAMPLES
The examples include the manufacturing process of polypropylene homopolymer composites using the natural reinforcement developed in this invention, according to the procedure proposed and developed herein.
Example 1
Preparation of the Submicrometer Natural Reinforcement
The process to obtain the submicrometer natural reinforcement from eggshells comprises the following steps:
a) Crushing in a mechanical device with flat metal blades. b) Sifting the crushed eggshells through ASTM 100 mesh. c) Drying the eggshells sifted below ASTM 100 mesh at 100° C. during 8 hours. d) Grinding the dry eggshells obtained in step (c) in a concentric metal ring mill during 10 minutes to obtain a mass equal to 200 grams of material. e) Sifting the ground eggshells through ASTM 400 mesh.
As a final product of the process described above, the natural eggshell reinforcement below ASTM 400 mesh is obtained. For 200 grams of ground mass, 90% passed through ASTM 400 mesh.
Table 1 shows the composition of the natural reinforcement and its crystallographic analysis by x-ray diffraction.
TABLE 1
Chemical and crystallographic analysis of the natural reinforcement
Composition
Content
Calcium carbonate
95% by weight
Organic matter, sulfated polysaccharides,
5% of dry weight
collagen and other proteins
Moisture
1-2%
X-ray diffraction crystallographic analysis:
99% calcite
The granulometric analysis of the natural submicrometer reinforcement or natural reinforcement is summarized in Table 2.
Table 2 shows the average particle size, or d(50), the particle size in a 10% proportion, or d(10), and the particle size in a 90% proportion, or d(90), together with the value of the surface area determined according to a BET nitrogen adsorption analysis.
TABLE 2
Characteristics of the natural reinforcement
Natural
Particle size (μm)
Surface area
reinforcement
d(10)
d(50)
D(90)
BET (m 2 /g)
1.7
8.4
27.5
18
Example 2
Procedure to Obtain Polypropylene Composites with Natural Reinforcement
The polypropylene composite with natural reinforcement from eggshells consists of the following raw materials:
1. Polypropylene. 2. Natural reinforcement from submicrometer eggshells. 3. Antioxidant.
The used commercial polypropylene homopolymers (PH) were supplied by Petroquim S.A. and correspond to three different melt flow indices: 4 (PH 013), 13 (PH 1310) and 26 (PH 2610), having the properties shown in Table 3.
TABLE 3 Characteristics of polypropylenes used in this invention. Crystallization Melting Molecular temperature temperature MFI* weight T c (T f ) Crystallinity (g/10 ×10 3 Type (° C.) (° C.) (%) min) (g/mol) PH 108.6 166.8 31.0 4 340 013 PH 113.4 164.7 42.9 13 250 1310 PH 118.3 166.9 45.1 26 170 2610 *MFIF = Melt flow index
Antioxidant:
The antioxidants Irganox 1010 and Irgafos 168, supplied by Petroquim S.A., were used in a 2:1 ratio, respectively.
This example describes the steps to obtain a polypropylene composite with 40% by weight of natural reinforcement and for a total mass of 40 grams, equivalent to the capacity of the used discontinuous mixer, comprising:
a) dosing and mixing the composite components—polypropylene PH 1310 (24 grams), antioxidant (0.048 grams) and dry natural reinforcement (16 grams)—in a discontinuous mixer at 190° C. and 75 rpm during 10 minutes under a stream of an inert gas like nitrogen; b) pressing at 40 bar and 30° C. the mass obtained from the mixing step in the discontinuous mixer to obtain 1-2 mm thick pressed sheets; and c) triturating the pressed material or polypropylene composite with 40% by weight of natural reinforcement, to obtain rectangular pieces approximately 1-3 mm long and wide.
The results are summarized in Table 5.
The procedure described was used for the preparation of composites made of polypropylene PH 013 and/or PH 2610 with 20 and 40% by weight of natural reinforcement as summarized in Table 5.
Example 3
At the same time, polypropylene composites with traditional mineral reinforcements (calcium carbonate or talc) were prepared according to the procedure described for the polypropylene composite with natural eggshell reinforcement. Commercial calcium carbonate and talc with three different average particle sizes and BET surface areas as summarized in Table 4 were used as traditional reinforcements.
Commercial Calcium Carbonates:
CC1 industrial (Truco)
CC2 Calfort 3 and
CC3 Microcarb 95T, both supplied by Reverté.
Commercial Talc:
TA1 industrial (Rocco)
TA2 HiTalc HTP2 and
TA3 HiTalc ultra5c, both supplied by Imifabi S.P.A.
TABLE 4
Characteristics of the traditional mineral reinforcements
Characteristics of the traditional mineral reinforcements
BET Surface
Particle size (μm)
area
Reinforcement
Nomenclature
d(10)
d(50)
d(90)
(m 2 /g)
Calcium
CC 1
2.7
17.1
42.6
2.2
carbonate
CC 2
0.4
2.0
10.2
3.2
CC 3
0.3
0.7
1.7
9.1
Talc
TA 1
3.0
10.7
29.5
4.6
TA 2
0.7
2.4
6.5
6.3
TA 3
0.4
0.5
2.8
11.9
This example describes the steps to obtain a polypropylene composite with 40% by weight of calcium carbonate CC1 mineral reinforcement and for a total mass of 40 grams, equivalent to the capacity of the used discontinuous mixer, comprising:
a) dosing and mixing the composite components—polypropylene PH 1310 (24 grams), antioxidant (0.048 grams) and dry CC1 reinforcement (16 grams)—in a discontinuous mixer at 190° C. and 75 rpm during 10 minutes under a stream of an inert gas like nitrogen, b) pressing at 40 bar and 30° C. the mass obtained from the mixing step in the discontinuous mixer to obtain 1-2 mm thick pressed sheets, and c) triturating the pressed material or polypropylene composite with 40% by weight of CC1 reinforcement, to obtain rectangular pieces approximately 1-3 mm long and wide.
The same procedure was used for the preparation of polypropylene composites PH 013 and PH 2610 with traditional mineral reinforcements CC2, CC3, TA1, TA2 and TA3 with 20%, 40% and 60% by weight of reinforcement as summarized in Table 5. The composites shown in Tables 5 and 6 are composed of polypropylene, antioxidant and reinforcement, wherein the percentage of polypropylene includes the antioxidant.
Example 4
Additionally, polypropylene composites with a mixture of reinforcements, i.e. mineral reinforcements such as talc and the natural reinforcement according to the procedure described for the polypropylene composite with natural eggshell reinforcement, were prepared. The traditional used reinforcement was commercial talc with three different average particle sizes and BET surface areas, as summarized in Table 4.
This example describes the steps to obtain a polypropylene composite with 40% by weight of total reinforcement, of which 10% by weight corresponds to the mineral reinforcement talc and 30% by weight to the natural reinforcement for a total mass of 40 grams, equivalent to the capacity of the used discontinuous mixer, comprising:
a) dosing and mixing the composite components—polypropylene PH 1310 (24 grams), antioxidant (0.048 grams), dry TA3 reinforcement (4 grams), and dry natural reinforcement (12 grams)—in the discontinuous mixer at 190° C. and 75 rpm during 10 minutes under a stream of an inert gas like nitrogen, b) pressing at 40 bar and 30° C. the mass obtained from the mixing step in the discontinuous mixer to obtain 1-2 mm thick pressed sheets, and c) granulating the pressed material or polypropylene composite with 40% by weight of total reinforcement (a mixture of 10% talc TA3 and 30% natural reinforcement), to obtain rectangular pieces approximately 1-3 mm long and wide.
The same procedure was used for the preparation of polypropylene composites PH 013 and PH 2610 with a mixture of mineral reinforcements TA1 or TA2 or TA3 and natural reinforcement in a proportion of 40% by weight of total reinforcement as summarized in Table 6. The composites shown in Table 6 comprise polypropylene, antioxidant and reinforcements, wherein the percentage of polypropylene includes the antioxidant.
The tests carried out to verify the mechanical and thermal properties of the polypropylene composites with natural reinforcement, as well as of the polypropylene composites with traditional mineral reinforcements and the polypropylene composites with mixtures of mineral reinforcement and natural reinforcement, were the following:
Tensile tests according to ASTM standard D 638, to determine Young's modulus in megapascals (MPa). Izod impact tests at −20° C. according to ASTM standard D 256, to determine the energy absorbed on impact in (J/m). Density tests according to ASTM standard 679 in g/cm 3 . Thermal tests by differential scanning calorimetry that allows the degree of crystallinity to be obtained as a percentage (%).
The results obtained from the above mentioned tests with the polypropylene composites with natural eggshell reinforcements, traditional mineral reinforcements and mixtures of mineral reinforcement and natural reinforcement, corresponding to 31 samples, are summarized in Table 5.
TABLE 5
Results of mechanical, thermal and density tests for polypropylene
composites with reinforcements.
Polymer
Young's
Polymer
MFI
Reinforcement
Polymer
Reinforcement
modulus
Density
Impact
Crystallinity
Sample
Type
(g/10 min)
Type
% peso
% weight
(MPa)
(g/cm3)
(J/m)
(%)
1
PH1310
13
100
1183
0.9120
38.3
43
2a
PH1310
13
CC1
80
20
1431
35.2
3a
PH1310
13
CC2
80
20
1405
4a
PH1310
13
CC3
80
20
1607
5a
PH1310
13
NR
80
20
1650
29.3
6a
PH1310
13
TA1
80
20
1674
25.6
7a
PH1310
13
TA2
80
20
1760
8a
PH1310
13
TA3
80
20
2304
2b
PH1310
13
CC1
60
40
1591
1.2435
19.6
51
3b
PH1310
13
CC2
60
40
1801
52
4b
PH1310
13
CC3
60
40
1866
46
5b
PH1310
13
NR
60
40
2017
1.2202
20.3
48
6b
PH1310
13
TA1
60
40
2135
10.3
46
7b
PH1310
13
TA2
60
40
2270
1.2213
14.2
52
8b
PH1310
13
TA3
60
40
2909
18.3
59
9
PH2610
26
100
1250
0.9116
37.2
10a
PH2610
26
CC1
80
20
1494
34.2
11a
PH2610
26
CC2
80
20
1497
12a
PH2610
26
CC3
80
20
1555
13a
PH2610
26
NR
80
20
1572
24.7
14a
PH2610
26
TA1
80
20
1825
30.9
15a
PH2610
26
TA2
80
20
1879
16a
PH2610
26
TA3
80
20
2288
10b
PH2610
26
CC1
60
40
1598
1.2399
20.5
11b
PH2610
26
CC2
60
40
1835
12b
PH2610
26
CC3
60
40
1918
13b
PH2610
26
NR
60
40
2323
1.2167
22.3
14b
PH2610
26
TA1
60
40
2323
18.3
15b
PH2610
26
TA2
60
40
2652
1.2387
16b
PH2610
26
TA3
60
40
2782
17
PH0610
4
100
1060
0.9322
38.0
39
18
PH0610
4
CC1
60
40
1602
36.3
45
19
PH0610
4
CC2
60
40
1734
20
PH0610
4
NR
60
40
1755
25.4
44
21
PH0610
4
TA1
60
40
2000
30.9
48
22
PH0610
4
TA2
60
40
2124
23
PH0610
4
CC1
40
60
1467
1.5354
16.5
43
24
PH0610
4
NR
40
60
2035
1.4869
12.5
42
25
PH0610
4
TA1
40
60
2239
1.5307
4.2
MFI = Melt flow index
NR = Natural reinforcement
TABLE 6
Results of mechanical tests for polypropylene composites with
reinforcements.
Polymer
Young's
Polymer
MFI
Reinforcement
Polymer
Reinforcement
modulus
Sample
Type
(g/10 min)
Type
% weight
% weight
MPa
8b
PH1310
13
TA3
60
40
2909
26
PH1310
13
TA3
60
20
NR
20
2660
27
PH1310
13
TA3
60
10
NR
30
2470
16b
PH2610
26
TA3
60
40
2782
28
PH2610
26
TA3
60
20
NR
20
2633
29
PH2610
26
TA3
60
10
RN
30
2531
30
PH0610
4
TA2
60
40
2124
31
PH0610
4
TA2
60
20
NR
20
2123
MFI = Melt flow index
RN = Natural reinforcement
According to the results shown in Tables 5 and 6, the tests carried out with the polypropylene composites with natural reinforcement, traditional mineral reinforcements and/or mixtures of mineral reinforcement and natural reinforcement have proved the competitiveness of the composite using the natural reinforcement developed in this invention with respect to the polypropylene composites using traditional mineral reinforcements such as calcium carbonate or talc.
The characteristics deduced from the results in Tables 5 and 6 for the polypropylene composites with natural reinforcement show that:
The polypropylene composites using natural reinforcement and/or using traditional mineral reinforcements have an increased Young's modulus, i.e. stiffness, with respect to polypropylene, according to the tensile tests carried out with the composites having the formulations indicated in Table 5.
In this respect it has been established that: The polypropylene composites using natural reinforcement of average particle size d(50)=8.4 μm showed greater stiffness than all the polypropylene composites using calcium carbonate as reinforcement, including the calcium carbonate with the smallest particle size, i.e. d(50)=0.5 μm. This was valid for composites with 20% and 40% by weight of reinforcement and also for all the used polypropylenes having different melt flow indices. The stiffness of the polypropylene composites with natural reinforcement of particle size d(50)=8.4 μm is lower than that of all the polypropylene composites with talc of average particle size d(50)=11.0, 2.4 and 0.5 μm for composites having 20% and 40% by weight of reinforcement and for all the used polypropylenes having different melt flow indices used. The greater stiffness of the polypropylene composites using talc, and in particular the polypropylene composite using talc TA3 with the smallest average particle size available commercially, d(50)=0.5 μm, is maintained when 50% to 75% of the talc is replaced by the natural reinforcement. That is, the hybrid composite of polypropylene formed using the reinforcement mixture of talc TA3 and natural reinforcement retains the stiffness of the polypropylene composite using only talc. This is observable for the compositions having 20% and 40% by weight of total reinforcement and for all the used polypropylenes having different melt flow index.
From the impact tests it was found that the impact energy absorbed by the polypropylene composites using reinforcement is lower than that of polypropylene, and it decreases as the proportion of reinforcement in the composite increases. In the case of composites using natural reinforcement, the rate of decrease of the absorbed energy is smaller as the weight proportion of the natural reinforcement increases when compared to the increases in the same weight proportion of the calcium carbonate and/or talc mineral reinforcements. This was valid for all the used polypropylenes having different melt flow indices. The density of the polypropylene composites using natural reinforcement is lower than the density of the polypropylene composites using calcium carbonate and/or talc mineral reinforcement. This lower density of the polypropylene composite using natural reinforcement is observable to a larger extent when the proportion by weight of natural reinforcement in the polypropylene composite increases from 40% to 60% by weight. From the thermal analysis it was found that the polypropylene composites with natural reinforcement have higher crystallinity than polypropylene. This is reflected in the thermal behavior of the composites, which means that changes in the degree of crystallinity are greater in the polypropylene composite using natural reinforcement than in the polypropylene composites using traditional calcium carbonate and/or talc reinforcements. This was used for the preparation of composites of polypropylene PH1310 and PH0610 having 40 and 60% by weight of reinforcement.
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This invention reveals polypropylene composites to be used in the automotive, electronics, packaging and textile industries, which comprises a polypropylene homopolymer in a proportion ranging from 10 to 60% by weight, a natural reinforcement based on eggshells, and an antioxidant. This invention also reveals a natural reinforcement produced from eggshells obtained as an agroindustrial waste, the process to obtain said composite, and the process to obtain such reinforcement. By means of this invention, polypropylene composites using the natural reinforcement are obtained that have improved mechanical and thermal behavior when compared to polypropylene composites using traditional mineral reinforcements.
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BACKGROUND OF THE INVENTION
Milbemycin, or B-41 is a substance which is isolated from the fermentation broth of a milbemycin producing strain of Streptomyces. The microorganism, the fermentation conditions and the isolation procedures are more fully described in U.S. Pat. No. 3,950,360 and U.S. Pat. No. 3,984,564. The milbemycin compounds described in said patents do not have any substitution at the 13-position.
SUMMARY OF THE INVENTION
The milbemycin antibiotics are converted to 13-hydroxy milbemycins by allylic bromination which affords the 13-bromo compounds, followed by acylation to produce the 13-acyl derivatives and hydrolysis of the 13-acyl to the 13-hydroxy group. Thus, it is an object of the instant invention to describe 13-hydroxy milbemycin compounds. It is a further object to describe the processes employed to produce such compounds. A still further object of this invention is to describe the antiparasitic uses of such 13-hydroxy milbemycins. Further objects will be apparent upon reading the following description.
DESCRIPTION OF THE INVENTION
Milbemycin and the instant 13-hydroxy derivatives thereof are described by the following structural formulae: ##STR1##
In the above formulae, when R 4 is hydrogen, milbemycin A 3 , A 4 , B 2 , B 3 , C 1 , C 2 (for formula I) and A 1 (for formula II) are described. Two other milbemycin compounds, A 2 and B 1 have not yet had their structures elucidated but such compounds are believed to have structures similar to the other milbemycins. In formula I the milbemycin compounds A 3 , A 4 , B 2 , B 3 , C 1 and C 2 are defined as follows:
______________________________________R.sub.1 R.sub.2 R.sub.3______________________________________A.sub.3 H CH.sub.3 CH.sub.3A.sub.4 H CH.sub.3 C.sub.2 H.sub.5B.sub.2 CH.sub.3 CH.sub.3 CH.sub.3B.sub.3 CH.sub.3 CH.sub.3 C.sub.2 H.sub.5C.sub.1 H ##STR2## CH.sub.3C.sub.2 H ##STR3## C.sub.2 H.sub.5______________________________________
In the foregoing formulae, the compounds of the instant invention are defined when R 4 is hydroxy. This position has been numbered as position 13 and such compounds are prepared from the corresponding 13-unsubstituted compounds (R 4 ═H) by the process outlined in the following reaction scheme. (Only partial structures are shown, the remainder of the molecules being as defined in formulae I and II). ##STR4##
In The foregoing process NBS represents an allylic bromination reagent which preferably is N-bromosuccinimide; and A 2 represents an acyl group, preferably a loweralkanoyl group.
A 13-unsubstituted milbemycin is brominated using allylic bromination techniques. Preferably the process uses N-bromosuccinimide and the reaction is promoted with the use of ultraviolet light. The reaction is carried out in an inert solvent; one resistant to bromination under the conditions employed. Fully halogenated solvents, such as carbon tetrachloride are preferable. The temperature is maintained at from 0° C to about room temperature, preferably from 10° to 20° C for a period of from 10 minutes to 5 hours. Generally, the reaction is complete in from 1 to 2 hours. The product is isolated using techniques known to those skilled in this art.
The bromo compound is treated with the alkali metal acylate, preferably the alkali metal salt of a lower alkanoic acid of from 2 to 4 carbon atoms. Sodium acetate is the preferred reagent and acetic acid is the preferred solvent. The reaction is carried out at from 0° to 50° C and is generally complete in from 10 hours to 3 days. Generally, the reaction is complete in from 18 to 36 hours at about room temperature. The 13-acyloxy intermediate is isolated using known techniques.
The 13-acyloxy compound is then hydrolized to the 13-hydroxy compound. The reaction is preferably base catalyzed using an alkali metal hydroxide, preferably sodium hydroxide. The reaction is generally carried out in an aqueous medium or a mixture of water and a lower alkanol. Temperatures of from 0° C to room temperature are acceptable, however, temperatures of from 0° to 10° C are preferred. The reaction is generally complete in about 5 to 24 hours and the product is isolated using known techniques.
The following examples of the best mode contemplated of this invention are provided in order that the invention might be more fully understood. The examples are not to be construed as limitative of the instant invention.
EXAMPLE 1
13-Bromo milbemycin B 2
A solution of 542 mg. of milbemycin B 2 and 178 mg. of N-bromo succinimide in 10 ml. of carbon tetrachloride is stirred under irradiation with ultraviolet light for 1 hour at room temperature. The mixture is cooled to 0° C, the succinimide is filtered off and the solvent is removed by evaporation under reduced pressure. Chromatography of a solution of the residue in a mixture of chloroform and tetrahydrofuran (95:5) over a column of silica yields 13-bromo milbemycin B z .
EXAMPLE 2
13-Acetoxy milbemycin B 2
A solution of 621 mg. of 13-bromo milbemycin B 2 and 82 mg. of anydrous sodium acetate in 10 ml. of acetic acid is stirred for 24 hours at 20°-30° C. The acetic acid is evaporated under reduced pressure and the product is separated from the sodium bromide by extraction with ether and evaporation. Chromatography of the product extracted into the ether in a mixture of chloroform and tetrahydrofuran (95:5) over a column of silica yields 13-acetoxy milbemycin B 2 .
EXAMPLE 3
13-Hydroxy milbemycin B 2
A solution of 600 mg. of 13-acetoxy milbemycin B 2 and 44 mg. of sodium hydroxide in a mixture of 8 ml. of methanol and 2 ml. of water is stirred for 10 hours at 0°-10° C. The solvent is evaporated under reduced pressure and the residue is dissolved in chloroform. Chromatography of the chloroform solution over a column of silica yields 13-hydroxy milbemycin B 2 .
Other milbemycin compounds such as A 1 , A 2 , A 3 , A 4 , B 1 , B 3 , C 1 , C 2 may be similarly converted into the 13-hydroxy derivative.
The novel compounds of this invention have significant parasiticidal activity as anthelmintics, insecticides and acaricides, in human and animal health and in agriculture.
The disease or group of diseases described generally as helminthiasis is due to infection of an animal host with parasitic worms known as helminths. Helminthiasis is a prevalent and serious economic problem in domesticated animals such as swine, sheep, horses, cattle, goats, dogs cats and poultry. Amoung the helminths, the group of worms described as nematodes causes widespread and often times serious infection in various species of animals. The most common genera of nematodes infecting the animals referred to above are Haemonchus, Trichostrongylus, Ostergagia, Nematodirus, Cooperia, Ascaris, Bunostomum, Oesophagostomum, Chabertia, Trichuris, Stongylus, Trichonema, Dictyocaulus, Capillaria, Heterakis, Toxocara, Ascaridia, Oxyuris, Ancylostoma, Uncinaria, Toxascaris and Parascaris. Certain of these, such as Nematodirus, Cooperia, and Oesophagostomum attack primarily the intestinal tract while others, such as Haemonchus and Ostertagia, are more prevalent in the stomach while still other such as Dictylocaulus are found in the lungs. Still other parasites may be located in other tissues and organs of the body such as the heart and blood vessels, subcutaneous and lymphatic tissue and the like. The parastic infections known as helminthiases lead to anemia, malnutrition, weakness, weight loss, severe damage to the walls of the intestinal tract and other tissues and organs and, if left untreated, may result in death of the infected host. The milbemycin derivatives of this invention have unexpectedly high activity against these parasites, and in addition are also active against Dirofilaria in dogs; Nematospiroides, Syphacia, Aspiculuris in rodents; arthropod ectoparasites of animals and birds such as ticks, mites, lice, fleas; blowfly, in sheep; Lucilia sp., biting insects and such migrating dipterous larvae as Hypoderma sp. in cattle; Gastrophilus in horses; and Cuterebra sp. in rodents.
The instant compounds are also useful against parasites which infect humans. The most common genera of parasites of the gastro-intestinal tract of man are Ancylostoma, Necator, Ascaris, Strongyloides, Trichinella, Capillaria, Trichuris, and Enterobius. Other medically important genera of parasites which are found in the blood or other tissues and organs outside the gastro-intestinal tract are the filiarial worms such as Wuchereria, Brugia, Onchocerca and Loa, Dracunculus and extra intestinal states of the intestinal worms Strongyloides and Trichinella. The compounds are also of value against arthropods parasitizing man, biting insects and other dipterous pests causing annoyance to man.
The compounds are also active against household pests such as the cockroach, Blatella sp., clothes moth, Tineola sp., carpet beetle, Attagenus sp. and the housefly Musca domestica.
The compounds are also useful against insect pests of stored grains such as Tribolium sp., Tenebrio sp., and of agricultural plants such as spider mites, (Tetranychus sp.), aphids, (Acyrthiosiphon sp.); against migratory orthopterans such as locusts and immature stages of insects living on plant tissue. The compounds are useful as a nematocide for the control of soil nematodes and plant parasites such as Meloidogyne spp. which may be of importance in agriculture.
These compounds may be administered orally in a unit dosage form such as a capsule, bolus or tablet, or as a liquid drench where used as an anthelmintic in mammals. The drench is normally a solution, suspension or dispersion of the active ingredient usually in water together with a suspending agent such as bentonite and a wetting agent or like excipient. Generally, the drenches also contain an antifoaming agent. Drench formulations generally contains from about 0.001 to 0.5% by weight of the active compound. Preferred drench formulations may contain from 0.01 to 0.1% by weight. The capsules and boluses comprise the active ingredient admixed with a carrier vehicle such as starch, talc, magnesium stearate, or di-calcium phosphate.
Where it is desired to administer the milbemycin compounds in a dry, solid unit dosage form, capsules, boluses or tablets containing the desired amount of active compound usually are employed. These dosage forms are prepared by intimately and uniformly mixing the active ingredient with suitable fnely divided diluents, fillers, disintegrating agents and/or binders such as starch, lactose, talc, magnesium stearate, vegetable gums and the like. Such units dosage formulations may be varied widely with respect to their total weight and content of the antiparasitic agent depending upon factors such as the type of host animal to be treated, the severity and type of infection and the weight of the host.
When the active compound is to be administered via an animal feedstuff, it is intimately dispersed in the feed or used as a top dressing or in the form of pellets which may then be added to the finished feed or optionally fed separately. Alternatively, the antiparasitic compounds of our invention may be administered to animals parenterally, for example, by intraruminal, intramuscular, intratracheal, or subcutaneous injection in which event the active ingredient is dissolved or dispersed in a liquid carrier vehicle. For parenteral administration, the active material is suitably admixed with an acceptable vehicle, preferably of the vegetable oil variety such as peanut oil, cotton seed oil and the like. Other parenteral vehicles such as organic preparation using solketal, glycerol, formal and aqueous parenteral formulations are also used. The active milbemycin derivatives are dissolved or suspended in the parenteral formulation for administration; such formulations generally contain from 0.005 to 5% by weight of the active compound.
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Derivatives of the antibiotic substance milbemycin, also identified as B-41 are prepared. Milbemycin is brominated, acetylated and hydrolized in order to prepare the 13-hydroxy derivative thereof. The novel derivatives have antiparasitic activity.
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[0001] This is a continuation of U.S. patent application Ser. No. 10/872,021, field Jun. 18, 2004, which claims foreign priority under 35 U.S.C. §119 to Japanese Patent Application No. 2003-191197, filed Jul. 3, 2003, the disclosure of which is herein incorporated by reference in their entirety.
BACKGROUND OF THE INVENTION
[0002] This invention relates generally to a piston engaged inside a cylindrical container, which serves as a movable bottom of the container and functions for enhancing fluidtightness inside the container.
[0003] As a piston for enhancing airtightness inside a cylinder, Japanese Patent Laid-open No. 1996-280804 discloses a piston for a syringe, for example. However, a cylinder produced by injection molding, for example, often has a tapered inner wall for production process convenience, and in that case, the conventional piston could not maintain fulidtightness because an internal diameter of the cylinder changes whereas the diameter of the piston does not significantly change. Further, the conventional piston is normally designed for short term use, and the seal between the piston and the inner wall tends to be degraded with time.
SUMMARY OF THE INVENTION
[0004] In view of the above, the present invention has been achieved. In an aspect, an object of the present invention is to provide a piston capable of securing fluidtightness, and a fluid container using the same. Another object of the present invention is to provide a piston usable for a tapered cylindrical container. Still another object of the present invention is to provide a piston capable of maintaining high fluidtightness for a long period of time. Yet another object of the present invention is to provide a piston having a simple structure which achieves at least one of the above objects.
[0005] The present invention is not intended to be limited by the above objects, and various objects other than the above can be accomplished as readily understood by one of ordinary skill in the art. The embodiments described below use reference numbers used in the drawings solely for easy understanding, and the reference numbers are not intended to limit the scope of the invention.
[0006] In an embodiment, the present invention provides a piston (e.g., 42 , 42 ′) adapted to be engaged inside a cylindrical container (e.g., 40 , 40 ′), constituted by an elastic member comprising: (i) a sliding member (e.g., 46 ) having an upper fluidtight portion (e.g., 421 ) and a lower fluidtight portion (e.g., 422 ), both of which fluidtightly and slidably contact an inner wall (e.g., 30 , 30 ′) of the cylindrical container; and (ii) a support member (e.g., 45 , 45 ′) having an upper concentric flexion (e.g., 423 a ) and a lower concentric flexion (e.g., 423 b ) to urge the sliding member against the inner wall of the cylindrical container.
[0007] The above embodiment includes, but is not limited to, the following embodiments.
[0008] The lower concentric flexion (e.g., 423 b ) may be disposed nearly half way between the upper fluidtight portion (e.g., 421 ) and the lower fluidtight portion (e.g., 422 ). The upper concentric flexion (e.g., 423 a ) may be disposed above the upper fluidtight portion. Each of the upper and lower concentric flexions may be disposed on a plane perpendicular to an axis (e.g., 47 ) of the piston. The support member may further have at least another concentric flexion (e.g., 423 c, 423 ′ c, 423 d ). The other concentric flexion may be arranged on a plane perpendicular to an axis (e.g., 47 ) of the piston between a plane on which the upper concentric flexion (e.g., 423 a ) is disposed and a plane on which the lower concentric flexion (e.g., 423 b ) is disposed. The upper and lower fluidtight portions (e.g., 421 , 422 ) each may be constituted by at least one annular convex portion (e.g., 421 a, 421 b, 422 a, 422 b ) (each fluidtight portion may include two or three annular convex portions).
[0009] In another aspect, the present invention provides a fluid container (e.g., 40 ) comprising: (a) a fluid-storing portion (e.g., 41 , 41 ′) for storing a fluid therein; (b) any one of the piston (e.g., 42 , 42 ′) of the foregoing engaged inside the fluid-storing portion, said piston serving as a bottom of the fluid-storing portion; (c) a nozzle head (e.g., 20 ) for discharging the fluid disposed on an upper side of the fluid-storing portion; and (d) a fluid discharge pump (e.g., 10 ) for discharging the fluid stored inside the fluid-storing portion from the nozzle head when the nozzle head is pressed.
[0010] The above embodiment includes, but is not limited to, the following embodiments.
[0011] The fluid-storing portion (e.g., 40 ) may be cylindrical and has an inner wall (e.g., 30 ) tapered toward the nozzle head (e.g., 20 ). The gradient of the tapered wall may be in the range of about 0° to about 10°, preferably more than about 0° but less than about 7°, more preferably about 1° to about 5°. Within the above ranges, the inner wall can have uneven surfaces.
[0012] The piston may have at least another concentric flexion (e.g., 423 d ), said other concentric flexion being arranged inward of the upper concentric flexion (e.g., 423 a ) and the lower concentric flexion (e.g., 423 b ) with respect to an axis (e.g., 47 ) of the piston and between the upper concentric flexion (e.g., 423 a ) and the lower concentric flexion (e.g., 423 b ) with respect to respective planes perpendicular to the axis of the piston. The lower concentric flexion (e.g., 423 b ) may be arranged nearly half way between the upper and lower fluidtight portions (e.g., 421 , 422 ). The upper concentric flexion (e.g., 423 a ) may be arranged above the upper fluidtight portion (e.g., 421 ).
[0013] In another embodiment, the present invention provides a piston (e.g., 42 , 42 ′) adapted to be engaged inside a cylindrical container (e.g., 40 , 40 ′), constituted by an elastic member comprising: (i) a sliding member (e.g., 46 ) having an upper fluidtight portion (e.g., 421 ) and a lower fluidtight portion (e.g., 422 ), both of which fluidtightly and slidably contact an inner wall (e.g., 30 , 30 ′) of the cylindrical container; and (ii) a support member (e.g., 45 , 45 ′) having an upper flexion (e.g., 423 a ) and a lower flexion (e.g., 423 b ) to urge the sliding member against the inner wall of the cylindrical container, each of the upper and lower flexions being disposed on a plane perpendicular to an axis (e.g., 47 ) of the piston.
[0014] The above embodiment includes, but is not limited to, the following embodiments.
[0015] A cross section of the cylindrical container, the upper flexion, and the lower flexion may have homologous shapes on a plane perpendicular to the axis. The homologous shapes mean that the shapes are nearly the same but different in size. The cylindrical container may have a cross section perpendicular to the axis which is not only a circle but also an oval or any other shape having no sharp inflection point in cross section.
[0016] In the above, a distance between the upper flexion (e.g., 423 a ) and the axis (e.g., 47 ) may be greater than a distance between the lower flexion (e.g., 423 b ) and the axis (e.g., 47 ). The lower flexion (e.g., 423 b ) may be disposed nearly half way between the upper fluidtight portion (e.g., 421 ) and the lower fluidtight portion (e.g., 422 ). The upper flexion (e.g., 423 a ) may be disposed above the upper fluidtight portion (e.g., 421 ). The support member further may have at least another homologous flexion (e.g., 423 c, 423 ′ c, 423 d ) inward of the upper and lower flexions (e.g., 423 a, 423 b ). The other flexion (e.g., 423 d ) may be arranged between the upper flexion (e.g., 423 a ) and the lower flexion (e.g., 423 b ) with respect to respective planes perpendicular to the axis (e.g., 47 ). The upper and lower fluidtight portions (e.g., 421 , 422 ) each may be constituted by at least one annular convex portion (e.g., 421 a, 421 b, 422 a, 422 b ).
[0017] In still another embodiment, the present invention provides a fluid container (e.g., 40 , 40 ′) comprising: (a) a fluid-storing portion (e.g., 41 , 41 ′) for storing a fluid therein; (b) any one of the piston (e.g., 42 , 42 ′) of the foregoing engaged inside the fluid-storing portion, said piston serving as a bottom of the fluid-storing portion; (c) a nozzle head (e.g., 20 ) for discharging the fluid disposed on an upper side of the fluid-storing portion; and (d) a fluid discharge pump (e.g., 10 ) for discharging the fluid stored inside the fluid-storing portion from the nozzle head when the nozzle head is pressed.
[0018] The above embodiment includes, but is not limited to, the following embodiments.
[0019] The fluid-storing portion may be cylindrical and has an inner wall (e.g., 30 ) tapered toward the nozzle head. The gradient of the tapered wall may be in the range described above.
[0020] The piston may have at least another flexion (e.g., 423 d ), said other flexion (e.g., 423 d ) being arranged inward of the upper and lower flexions (e.g., 423 a, 423 b ) with respect to an axis (e.g., 47 ) of the piston and between the upper and lower flexions (e.g., 423 a, 423 b ) with respect to respective planes perpendicular to the axis (e.g., 47 ) of the piston. The lower flexion (e.g., 423 b ) may be arranged nearly half way between the upper and lower fluidtight portions (e.g., 421 , 422 ). The upper flexion (e.g., 423 a ) may be arranged above the upper fluidtight portion (e.g., 421 ).
[0021] The sliding member and the supporting member may preferably be configured to provide at least 4% elastic deformation evenly in a radial direction (including about 5%-about 10%), although an elastic deformation may range from about 3% to about 30% in an embodiment. The flexions and the material enable the above, so that the piston can fit in a cylindrical container having a different inner diameter, a different shape, an uneven inner wall, an slanted inner wall, etc., without degrading fluidtightness between the piston and the inner wall of the cylindrical container from the bottom position to the top position of the piston in the cylindrical container. The sliding member may basically have an outer periphery corresponding to the inner cross section of the cylindrical container, which has a larger diameter than the maximum diameter of the cylindrical container in accordance with the degree of elastic deformation of the piston and the shape of the inner wall of the cylindrical container.
[0022] The piston may be constituted by any suitable material such as a resin, rubber, composite, etc. Preferably, the piston may be constituted by a resin such as polypropylene or polyethylene, a resin containing a rubber material such as silicon rubber, a mixture of the foregoing, and the like. Hardness of the material can be adjusted by adjusting a ratio of a hard resin to a soft resin. Further, in the present invention, all of the elements can be made of a resin, rubber, composite, or mixture thereof, and the hardness and elasticity of each can be adjusted depending on the function required for the element. For example, a bending or flexing portion (e.g., a valve body) can be made of a more flexible material than the other portions (e.g., a valve seat).
[0023] In the present invention, the flexion may be an elbow having an acute angle or a point of turning in a cross section along the axis. Each flexion may be on a plane perpendicular to the axis. The flexions may be comprised of at least one upper flexion and one lower flexion; e.g., from the outer periphery to the center, (I) an upper flexion and an lower flexion, (II) a first upper flexion, a lower flexion, and a second upper flexion, (III) a first lower flexion, an upper flexion, and a second lower flexion, etc. In a preferable embodiment, the plane perpendicular to the axis on which the second lower flexion is arranged is closer to the upper fluidtight portion than is the plane on which the first lower flexion is arranged, so that the piston can smoothly travel upward without degrading fluidtightness as the fluid inside is used. For the same reason, as described above, in a preferable embodiment, the plane on which the first lower flexion is arranged is nearly half way between the upper fluidtight portion and the lower fluidtight portion.
[0024] In all of the foregoing embodiments, any element used in an embodiment can interchangeably be used in another embodiment, and any combination of elements can be applied in these embodiments, unless it is not feasible.
[0025] For purposes of summarizing the invention and the advantages achieved over the related art, certain objects and advantages of the invention have been described above. Of course, it is to be understood that not necessarily all such objects or advantages may be achieved in accordance with any particular embodiment of the invention. Thus, for example, those skilled in the art will recognize that the invention may be embodied or carried out in a manner that achieves or optimizes one advantage or group of advantages as taught herein without necessarily achieving other objects or advantages as may be taught or suggested herein.
[0026] Further aspects, features and advantages of this invention will become apparent from the detailed description of the preferred embodiments which follow.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] These and other features of this invention will now be described with reference to the drawings of preferred embodiments which are intended to illustrate and not to limit the invention.
[0028] FIG. 1 is a longitudinal view of a fluid container according to Embodiment 1 of the present invention, where a piston is at the bottom of the container.
[0029] FIG. 2 is a longitudinal view of the fluid container according to Embodiment 1 of the present invention, wherein the piston is at the top of the container.
[0030] FIG. 3 is an enlarged longitudinal view of the fluid discharge pump 10 the nozzle head 20 in the closed position, wherein an inflow portion 211 is not communicated with an opening portion 222 .
[0031] FIG. 4 is a longitudinal view of the fluid discharge pump 10 the nozzle head 20 in the open position, wherein the inflow portion 211 is communicated with the opening portion 222 .
[0032] FIGS. 5 ( a )-( c ) are a side view, cross sectional view, and bottom view, respectively, showing an inflow valve seat member 111 in an embodiment comprising an inflow valve mechanism 11 in the fluid discharge pump 10 .
[0033] FIGS. 6 ( a )-( c ) are a side view, cross sectional view, and bottom view, respectively, showing an inflow valve member 112 in an embodiment comprising the inflow valve mechanism 11 in the fluid discharge pump 10 .
[0034] FIGS. 7 ( a )-( c ) are a top view, cross sectional view, and bottom view, respectively, showing an outflow valve seat member 121 in an embodiment comprising the outflow valve mechanism 12 in the fluid discharge pump 10 .
[0035] FIGS. 8 ( a )-( c ) are a top view, side view, and bottom view, respectively, showing an outflow valve member 122 in an embodiment comprising the outflow valve mechanism 12 in the fluid discharge pump 10 .
[0036] FIG. 9 is an explanatory view showing dismantling the nozzle head 20 in a closed position in an embodiment.
[0037] FIG. 10 is an explanatory view showing dismantling the nozzle head 20 in an open position in an embodiment.
[0038] FIG. 11 is a front view of the nozzle head 20 in the closed position.
[0039] FIG. 12 is a front view of the nozzle head 20 in the open position.
[0040] FIG. 13 is an enlarged longitudinal view showing the fluid discharge pump 10 and the nozzle head 20 in the open position, where the nozzle head is pressed.
[0041] FIG. 14 is an enlarged longitudinal view showing the fluid discharge pump 10 and the nozzle head 20 in the open position, wherein the nozzle head is released.
[0042] FIGS. 15 ( a )-( c ) are a top view, side view, and cross sectional view of A-A line, respectively, showing a piston member 42 in an embodiment comprising the fluid-storing portion 40 .
[0043] FIGS. 16 ( a )-( c ) are a top view, side view, and cross sectional view of A-A line, respectively, showing the piston member 42 in an alternative embodiment.
[0044] FIG. 17 is a longitudinal view showing a fluid container according to Embodiment 2 of the present invention, where a piston is at the bottom of the container.
[0045] FIG. 18 is a longitudinal view showing the fluid container according to Embodiment 2 of the present invention, wherein the piston is at the top of the container.
[0046] Explanation of symbols used is as follows: 10 : Fluid discharge pump; 11 : Inflow valve mechanism; 12 : Outflow valve mechanism; 16 : Bellows member; 16 a: Inflow opening; 16 b: Outflow opening; 17 : Packing; 20 : Nozzle head; 21 : Tubular member; 22 : Guiding member; 40 : Fluid-storing portion; 41 : Cylinder member; 42 : Piston member; 43 : Inner lid; 43 a: Air vent; 43 b: Upper side of the bottom; 44 : Outer lid; 44 a: Hole; 111 : Inflow valve seat member; 111 a: Opening portion; 111 b: Joined portion; 112 : Inflow valve member; 112 a: Valve body; 112 b: Supporting portion; 112 c: Coupling portion; 121 : Outflow valve seat member; 121 a: Opening portion; 121 b: Joined portion; 121 c: Inflow portion; 122 : Outflow valve member; 122 a: Valve body; 122 b: Base portion; 211 : Inflow portion; 212 : Outflow portion; 213 : Convex portion; 214 : Engaging portion; 215 : Knob portion; 221 : Pushing portion; 222 : Opening portion; 223 : Guiding portion; 223 a: First regulating portion; 223 b: Second regulating portion; 224 : Groove portion; 421 : Fluidtight portion; 421 a: Convex portion; 421 b: Convex portion; 422 : Fluidtight portion; 422 a: Convex portion; 422 b: Convex portion; 423 : 423 : Flexion.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0047] As explained above, the present invention can be accomplished in various ways including, but not limited to, the foregoing embodiments. The present invention will be explained in detail with reference to the drawings, but the present invention should not be limited thereto.
[0048] Preferred embodiments of the present invention are described by reference to drawings. FIGS. 1 to 2 are longitudinal cross-sections of the fluid container according to an embodiment of the present invention.
[0049] This fluid container may be used as a container for beauty products for storing gels such as hair gels and cleansing gels, creams such as nourishing creams and cold creams or liquids such as skin lotions used in the cosmetic field. Additionally, this fluid container also can be used as a container for medicines, solvents or foods, etc. In this specification, high-viscosity liquids, semifluids, gels that sol solidifies to a jelly, and creams and regular liquids are all referred to as fluids. Preferably, the fluid is a flowable or dischargable substance including a liquid phase, a liquid and solid mixed phase, a solid and gas mixed phase, a liquid, solid, and gas mixed phase when being stored in the container. Preferably, fluidtightness is liquidtightness.
[0050] The fluid container according to an embodiment of the present invention comprises a fluid pump 10 , a nozzle head 20 switchable between an open position enabling a fluid to pass through between inside and outside the fluid container and a closed position shutting off passage of the fluid, and a fluid-storing portion storing the fluid therein.
[0051] Additionally, in this specification, upward and downward directions in FIGS. 1 and 2 are defined as upward and downward directions in the fluid container. In other words, in the fluid container according to the embodiment of the present invention, the side of the nozzle head 20 shown in FIG. 1 is defined as the upward direction; the side of a piston member 42 is defined as the downward direction.
[0052] The fluid-storing portion 40 has a tubelike cylinder member 41 , a piston member traveling inside the cylinder member 41 up and down, an inner lid 43 in which multiple air vents 43 a are formed, and an outer lid 44 . The cylinder member 41 in the fluid-storing portion 40 and the fluid discharge pump 10 are connected fluidtightly via packing 17 . Additionally, if an inflow valve mechanism 11 connected with the cylinder member of the fluid discharge pump 10 is adequately elastic, the packing 17 can be omitted.
[0053] The outer lid 44 is attached to the lower portion of the cylinder member 41 in a position in which the outer lid 44 holding the inner lid 43 between the outer lid 44 and the lower portion of the cylinder member 41 . In the inner lid 43 , the upper side of the bottom 43 b for positioning the tail end of the piston member 42 inside the fluid-storing container is formed. By changing a height of this upper side of the bottom 43 b, a storable fluid amount inside the fluid-storing container can be changed.
[0054] Additionally, a hole 44 a is formed in the central portion of the outer lid 44 . Because of this hole, the air can pass through between outside of the fluid container and the air vents 43 a formed in the inner lid 43 .
[0055] The piston member 42 may require a configuration allowing the piston member 42 to travel smoothly inside the cylinder member while achieving high liquidtightness. A configuration of the piston member 42 for serving this purpose is described in detail later.
[0056] In this fluid container, by reciprocating the piston member 42 up and down by pressing the nozzle head 20 switched over to the open position, a fluid stored inside the fluid-storing portion 40 is discharged from the nozzle head 20 by the action of the fluid discharge pump 10 described in detail later. As a fluid amount inside the fluid-storing portion 40 decreases, the piston member 42 travels toward the nozzle head 20 inside the cylinder member 41 as shown in FIG. 2 .
[0057] FIG. 3 is a longitudinal cross section showing the fluid discharge pump 10 and the nozzle head 20 in the closed position; FIG. 4 is a longitudinal cross section showing he fluid discharge pump 10 and the nozzle head 20 in the open position.
[0058] The fluid discharge pump 10 may comprise a resinous bellows member 16 having an inflow opening 16 a and an outflow opening 16 b, a resinous inflow valve mechanism 11 fixed in the inflow opening 16 b of the bellows member 16 , and the resinous outflow valve mechanism 12 fixed in the outflow opening 16 b of the bellows member. The inflow valve mechanism 11 here may be used for letting a fluid stored inside the fluid-storing portion 40 flow into the fluid discharge pump 10 as the bellows member 16 stretches; the outflow valve mechanism 12 may be used for letting the fluid having flowed into the fluid discharge pump flow out to the nozzle head as the bellows member 16 folds up.
[0059] FIG. 5 ( a ) is a front view of an inflow valve seat member 111 comprising the inflow valve mechanism 11 in the fluid discharge pump 10 ; FIG. 5 ( b ) is a lateral cross section of the same; FIG. 5 ( c ) is a backside view of the same. FIG. 6 ( a ) is a front view of the inflow valve member 112 comprising the inflow valve mechanism 11 in the fluid discharge pump 10 ; FIG. 6 ( b ) is a cross section of the same; FIG. 6 ( c ) is a backside view of the same.
[0060] As shown in FIGS. 5 ( a )-( c ), the inflow valve seat member 111 may comprise an opening portion 111 a for letting a fluid inside the fluid-storing portion 40 flow in, and a joined portion 111 b to be joined with the inflow valve member 112 described later.
[0061] As shown in FIGS. 6 ( a )-( c ), the inflow valve member 112 may comprise a valve body 112 a having a shape corresponding to a shape of the opening portion 111 a of the inflow valve seat member 111 , a supporting portion 112 b fixed in the joined portion 111 b of the inflow valve seat member 111 , and four coupling portions 112 c for coupling the valve body 112 a and the supporting portion 112 b. The respective four coupling portions 112 c may have one pair of flexions 112 d, hence adequate flexibility is provided.
[0062] FIG. 7 ( a ) is a plane view showing an outflow valve seat member 121 comprising an outflow valve mechanism 12 in the fluid discharge pump 10 ; FIG. 7 ( b ) is a lateral view of the same; FIG. 7 ( c ) is a backside view of the same. FIG. 8 ( a ) is a plane view showing an outflow valve member 122 comprising then outflow valve mechanism 12 in the fluid discharge pump 10 ; FIG. 8 ( b ) is a lateral view of the same; FIG. 8 ( c ) is a backside view of the same.
[0063] As shown in FIGS. 7 ( a )-( c ), the outflow valve seat member 121 may comprise an opening portion 121 a, a joined portion 121 b joined with the outflow valve member 122 described later, and an inflow portion 121 c for letting a fluid inside the fluid discharge pump 10 flow in.
[0064] As shown in FIGS. 8 ( a )-( c ), the outflow valve member 122 may comprise a nearly dish-shaped flexible valve portion 121 a contacting an inner surface of the opening portion 121 a of the outflow valve seat member 121 , and a base portion 122 b joined with the joined portion 121 b of the outflow valve seat member 12 . In the base portion 122 b, a passage groove 122 c for letting the fluid flow in is formed.
[0065] FIG. 9 is an explanatory cutaway view showing a portion of the nozzle head 20 in the closed position; FIG. 10 is an explanatory cutaway view showing a portion of the nozzle head 20 in the open position.
[0066] The nozzle head 20 may comprise a tubular member 21 and a guiding member 22 . The tubular member 21 may have an inflow portion 211 for letting the fluid flow in from the outflow valve mechanism 12 in the fluid discharge pump described later, an outflow portion 212 for letting the fluid having flowed in from the inflow portion 211 flow out, a convex portion 213 guided by the guiding member 22 , and an engaging portion 214 .
[0067] The guiding member 22 may have a pushing portion 221 , an opening portion 222 communicated with the inflow portion 211 of the tubular member 21 in an open position, a guiding portion 223 guiding a switchover between an open position and a closed position of the tubular member 21 described later, and a groove portion 224 having a shape corresponding to the engaging portion 214 of the tubular member 21 .
[0068] The engaging portion 214 of the tubular member 21 may be fitted in the groove portion 224 in the guiding member 22 . By this, the tubular member 21 can be supported rotatably on its shaft center against the guiding member.
[0069] With the above-mentioned configuration provided, it is possible to switch the nozzle head 20 between the open position and the closed position: In the open position, the inflow portion 211 of the tubular member 21 and the opening portion 222 of the guiding member 22 are communicated, and fluid passage between the inflow portion 211 of the tubular member 21 and the outflow valve mechanism described later is enabled; in the closed position, fluid passage between the inflow portion 211 and the outflow valve mechanism 12 is shut off. Consequently, when the nozzle head 20 is switched over to the closed position, it becomes possible to fully prevent leaking out of the fluid from the fluid container.
[0070] FIG. 11 is a front view of the nozzle head 20 in the closed position; FIG. 12 is a front view of the nozzle head 20 in the open position.
[0071] Switching over of the nozzle head 20 between the open position and the closed position may be achieved by rotating the tubular member 21 on its shaft center against the guiding member 22 . At this time, the convex portion 21 of the tubular member 21 may be guided by the guiding portion 223 of the guiding member 22 .
[0072] Additionally, the guiding member 22 may have a first regulating portion 223 a and a second regulating portion 223 b. The first regulating portion 223 a stops a rotation of the tubular member by contacting the convex portion 213 of the tubular member 21 in the open position; the second regulating portion stops a rotation of the tubular member by contacting the convex position 213 of the tubular member 21 in the closed position. By these first regulating portion 223 a and second regulating portion 223 b, a switchover between the open position and the closed position can be achieved easily.
[0073] Fluid discharge actions in the above-mentioned fluid container are described below.
[0074] FIGS. 13 and 14 are longitudinal cross sections showing the fluid discharge pump 10 and the nozzle head 20 in the open position. Of these, FIG. 13 shows a position in which, with the pushing portion 221 in the nozzle head 20 being pressed, the bellows member 16 is deforming to a folded-up position in which it holds a relatively small amount of fluid from a stretched position in which it holds a relatively large amount of fluid inside it; FIG. 14 shows a position in which, with a pressure applied to the pushing portion 221 in the nozzle head 20 removed, the bellows member 16 is deforming back to the stretched position again.
[0075] As shown in FIG. 13 , when the pushing portion 221 in the nozzle head 20 is pressed, a capacity of the bellows member 16 may reduce and inside the fluid discharge pump 10 may be pressurized. By this, the valve body 112 a of the inflow valve member 112 can be disposed in a position in which it contacts the opening portion 111 a of the inflow valve seat member 111 and the opening portion 11 a is closed; simultaneously, the valve body 122 a of the outflow valve member 122 can be disposed in a position in which it separates from the opening portion 121 a of the outflow valve seat member 121 and the opening portion 121 a is open. Consequently, the fluid inside the fluid discharge pump 10 flows out to the outflow portion 212 of the nozzle head 20 in the open portion.
[0076] As shown in FIG. 14 , when a pressure applied to the pushing portion 221 in the nozzle head 20 is removed, a capacity of the bellows member 16 may expand by the resilience of the bellows member 16 and inside the fluid discharge pump may be depressurized. By this, the valve body 112 a of the inflow valve member 112 may be disposed in a position in which it separates from the opening portion 111 a of the inflow valve seat member; simultaneously, the valve body 122 a of the outflow valve member 122 may be disposed in a position in which it contacts the opening portion 121 a of the outflow valve seat member 121 . Consequently, the fluid stored inside the fluid-storing portion 40 can flow into the fluid discharge pump 10 .
[0077] A configuration of the fluid-storing portion 40 is described below.
[0078] The cylinder member 41 used for this fluid-storing portion 40 may be made of an injection molded resin. Consequently, as shown in FIGS. 1 and 2 , for production process convenience, etc., a tip of the cylinder member 41 may have a tapered shape.
[0079] FIG. 15 ( a ) is a plane view showing the piston member 42 comprising the fluid-storing portion 40 ; FIG. 15 ( b ) is a front view of the same; FIG. 15 ( c ) is a cross section showing an A-A section in FIG. 15 ( a ).
[0080] On the upper side of this piston member 42 , a fluidtight portion 421 contacting an inner circumference of the cylinder member 41 may be formed; on the underside of the piston member 42 , a fluidtight portion 422 contacting an inner circumference of the cylinder member 41 may be formed. In other words, on an outer peripheral surface of the piston member 42 , a pair of fluidtight portions 421 , 422 respectively contacting an inner circumference of the cylinder member 41 may be disposed apart from each other at a certain distance.
[0081] A contacting portion in the fluidtight portion 421 , which contacts an inner circumference of the cylinder member 41 , may comprise a pair of convex portions 421 a, 421 b disposed adjacently. A contacting portion in the fluidtight portion 422 , which contacts an inner circumference of the cylinder member 41 , may comprise a pair of convex portions 422 a, 422 b disposed adjacently.
[0082] In this piston member 42 , by the action of a pair of fluidtight portions 421 , 422 , which are disposed apart from each other at a certain distance, the shaft center of the piston member 42 and the shaft center of the cylinder member 41 always can be brought in line regardless of a direction of stress applied to the piston member 42 . Consequently, it becomes possible for the piston member 42 to smoothly travel inside the cylinder member 41 .
[0083] Additionally, in the piston member 42 , concentric flexions 423 a, 423 b, 423 c with the fluidtight portions 421 , 422 , which serve as contacting portions contacting the inner circumference of the cylinder member 41 , may be formed in a plane perpendicular to a traveling direction of the piston member inside the cylinder member 41 . The piston member 42 , therefore, may have momentum from the central portion to an outer perimeter in a plane perpendicular to a traveling direction of the piston member inside the cylinder member 41 and may be configured to be capable of expanding and contracting according to a shape of the inner circumference of the cylinder member 41 . Consequently, in the case of the cylinder member 41 having a tapered shape toward a nozzle direction or the cylinder member 41 having a low accuracy, i.e., having an uneven internal surface, it becomes possible to secure adequate liquidtightness for the cylinder member 41 and the piston member 42 , not by altering an inside diameter of the cylinder 41 .
[0084] Furthermore, because more flexions are formed above the central portion of the piston member 42 than below the central portion, as shown in FIG. 2 , it becomes possible to get relatively a small amount of the fluid remaining inside the fluid-storing portion 40 when the piston member 42 travels to the most elevated position inside the cylinder member 41 .
[0085] FIGS. 16 ( a )-( c ) are explanatory views each showing the piston member 42 ′ in an alternative embodiment. While three flexions 423 a, 423 b, 423 c are formed in the piston member 42 in the fluid container according to Embodiment 1, five flexions 423 a, 423 b, 423 ′ c, 423 d, 423 e also can be formed in this embodiment as shown in FIGS. 16 ( a )-( c ). Additionally, the number of flexions formed can be other than five, or it can be a single one.
[0086] FIGS. 17 and 18 are longitudinal cross sections showing the fluid container according to a further alternative embodiment (Embodiment 2). While a cylinder member 41 in the fluid container according to the embodiments previously described has a tapered inner surface 30 , even when the cylinder member having a non-tapered inner surface 30 ′ as shown as a cylinder member 41 ′ of a container 40 ′ in FIGS. 17 and 18 is used, the piston member 42 shown in FIGS. 15 ( a )-( c ) and 16 ( a )-( c ) also can be used.
[0087] According to an embodiment of the present invention, when the piston comprises an elastic member in which a concentric flexion with an outer perimeter is formed in a plane perpendicular to a traveling direction of the piston inside the cylinder and has momentum from the central portion in an outer peripheral direction, it becomes possible to secure airtightness even when a cylinder diameter changes.
[0088] According to another embodiment of the present invention, when in the fluid container possessing a fluid discharge pump for discharging a fluid stored inside a fluid-storing portion from a nozzle head disposed on the upper side of the fluid-storing portion by pressing the nozzle head, the fluid-storing portion possesses a cylinder member, and a piston engaged inside the cylinder member, which comprises an elastic member in which a concentric flexion with an outer perimeter is formed in a plane perpendicular to a traveling direction of the piston inside the cylinder member, and has momentum from the central portion in an outer peripheral direction, it becomes possible to secure airtightness even when a cylinder diameter changes.
[0089] According to still another embodiment of the present invention, when the cylinder member has a tapered shape toward the nozzle head, throughput of the cylinder member is improved; simultaneously it becomes possible to secure airtightness even when a cylinder diameter changes.
[0090] According to yet another embodiment of the present invention, when within a contacting surface of the piston, which contacts the cylinder, more flexions are formed in a tapered direction of the cylinder member, it becomes possible to get relatively a small amount of the fluid remaining inside the fluid-storing portion 40 when the piston member 42 travels to the most elevated position inside the cylinder member 41 .
[0091] It will be understood by those of skill in the art that numerous and various modifications can be made without departing from the spirit of the present invention. Therefore, it should be clearly understood that the forms of the present invention are illustrative only and are not intended to limit the scope of the present invention.
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A piston configured to be engaged inside a cylindrical container includes: a sliding member having an upper fluidtight portion and a lower fluidtight portion; and a support member connected to the sliding member and having concentric flexions for urging the sliding member against the inner wall of the cylindrical container. The upper and lower fluidtight portions are each constituted by at least one annular convex bump portion having a thickness which is the greatest at a point where the annular convex bump portion is in contact with the inner wall of the cylinder.
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REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority of Korean Patent Application No. 2002-58857, filed Sep. 27, 2002, the entire disclosure of which is incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to semiconductor packages and methods for making the same. More particularly, the present invention relates to discrete packaging for semiconductor devices having an insulated ceramic heat sink and methods for making the same.
BACKGROUND OF THE INVENTION
[0003] [0003]FIG. 1 illustrates a cross-sectional view of a conventional discrete package 100 for semiconductor devices (also referred to as a semiconductor package, discrete package, or package). Referring to FIG. 1, the discrete package 100 has a structure in which a ceramic layer 120 , a lead frame pad 130 , and a semiconductor chip 140 are sequentially formed on a heat sink 110 . The heat sink 110 , the ceramic layer 120 , the lead frame pad 130 , and the semiconductor chip 140 are encapsulated by any molding material 150 , such as an epoxy molding compound (EMC). To discharge heat to the outside of the package, the bottom of the heat sink 110 is usually not encapsulated and is therefore exposed to the outside of the package.
[0004] A soldering process is often performed on the heat sink 110 , the ceramic layer 120 , the lead frame pad 130 , and the semiconductor chip 140 using a solder formed of PbSnSb. The soldering process attaches the ceramic layer 120 on the heat sink 110 , the lead frame pad 130 on the ceramic layer 120 , and the semiconductor chip 140 on the lead frame 130 . However, as well known in the art, ceramics are materials that can be difficult to be solder to other materials. Thus, in order to attach the ceramic layer 120 to the heat sink 110 and to the lead frame pad 130 , upper and lower surfaces 120 a and 120 b of the ceramic layer 120 are often coated with any conductive layer pattern. The conductive layer pattern may be formed of a conductive material like gold (Ag). Costs for fabricating a ceramic layer 120 coated with a conductive layer pattern are more expensive (by about three times) than a ceramic layer 120 that is not coated with a conductive layer pattern. Moreover, the soldering process must be carried out three times to successively attach the heat sink 110 , the ceramic layer 120 , the lead frame pad 130 , and the semiconductor chip 140 . This lengthy procedure can increase the costs for manufacturing the discrete package 100 .
[0005] [0005]FIG. 2 is a cross-sectional view of another conventional discrete package 200 . As shown in FIG. 2, the discrete package 200 contains a direct bonding copper (DBC) substrate 210 that is used for thermal insulation and discharge. The DBC substrate 210 has a structure in which a lower copper layer 212 and an upper copper layer 216 are bonded to the lower and upper surfaces, respectively, of a ceramic layer 214 . A semiconductor chip 220 is attached to an upper surface of the upper copper layer 216 using a soldering process. Leads (not shown) are formed on the upper copper layer 216 of the DBC substrate 210 . The DBC substrate 210 and the semiconductor chip 220 are encapsulated by any molding material 230 so that the lower surface of the lower copper layer 212 and portions of the leads connected to the upper copper layer 216 are not encapsulated and are exposed to the outside of the molding material 230 .
[0006] By using the DBC substrate 210 , the discrete package 200 improves its insulating characteristics and thermal transfer efficiency. To make the discrete package 200 , however, a two-step soldering process is performed between the DBC substrate 210 and the leads, as well as between the DBC substrate 210 and the semiconductor chip 220 . This two-step soldering process requires high manufacturing costs. Also, costs for manufacturing the DBC substrate 210 are more expensive (about eight times) than the costs for manufacturing a bare ceramic layer.
[0007] [0007]FIG. 3 is a cross-sectional view of still another conventional discrete package 300 . As shown in FIG. 3, the discrete package 300 contains a lead frame pad 310 (which also acts as a heat sink) and a semiconductor chip 320 attached on an upper surface 310 a of the lead frame pad 310 by a soldering process. The lead frame pad 310 and the semiconductor chip 320 are entirely encapsulated by a molding material 330 . Since the lower surface 310 b of the lead frame pad 310 is encapsulated by the molding material 330 , the discrete package 300 can be insulated from the outside.
[0008] Manufacturing the discrete package 300 only requires a one-step soldering process between the lead frame pad 310 and the semiconductor chip 320 , thereby reducing manufacturing costs. As well, using the molding material 330 enables the discrete package 300 to be insulated from the outside. Despite these advantages, however, the discrete package 300 is inconvenient to use because the thermal transfer efficiency of EMC (the material often used in the molding material 330 ) is more than ten times lower than those of ceramic materials.
SUMMARY OF THE INVENTION
[0009] The present invention provides a discrete package having a high insulating and thermal transfer efficiency, yet which can be manufactured at a low cost.
[0010] According to one aspect of the present invention there is provided a discrete package containing: a lead frame pad with a first surface and a second surface, wherein the second surface is opposite the first surface; leads connected to a side of the lead frame pad; a semiconductor chip attached to the first surface of the lead frame pad; a ceramic layer which is positioned to directly contact the second surface of the lead frame pad; and a molding material which entirely encapsulates the lead frame pad, the semiconductor chip, and a portion of the ceramic layer, except the leads and the second surface of the ceramic layer.
[0011] According to another aspect of the present invention there is provided a discrete package containing: a lead frame pad which has a first surface and a second surface, the second surface being opposite the first surface; leads which are connected to a side of the lead frame pad; a semiconductor chip which is attached to the first surface of the lead frame pad; a ceramic layer which is attached with the second surface of the lead frame pad via an epoxy; and a molding material which entirely encapsulates the lead frame pad, the semiconductor chip, and a portion of the ceramic layer, except the leads and the second surface of the ceramic layer.
[0012] In both aspects of the invention, the leads can be formed to have steps with respect to the lead frame pad. As well, the discrete package can further include wires which electrically connect the leads to the semiconductor chip. Also, the lead frame pad can be formed to a thickness of 0.5 mm. Further, the discrete package can further include an adhesive between the lead frame pad and the semiconductor chip.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The above and other aspects and advantages of the present invention will become more apparent by describing in detail the preferred aspects thereof with reference to the attached drawings in which:
[0014] [0014]FIG. 1 is a cross-sectional view of a conventional discrete package;
[0015] [0015]FIG. 2 is a cross-sectional view of another conventional discrete package;
[0016] [0016]FIG. 3 is a cross-sectional view of still another conventional discrete package;
[0017] [0017]FIG. 4 is a plan view of an upper surface of a discrete package according to the present invention;
[0018] [0018]FIG. 5 is a plan view of a lower surface of a discrete package according to one aspect of the present invention;
[0019] [0019]FIG. 6 is a cross-sectional view of a discrete package according to one aspect of the present invention, taken along the line A-A′ of FIGS. 4 and 5;
[0020] [0020]FIG. 7 is cross-sectional view of a discrete package according to another aspect of the present invention, taken along the line A-A′ of FIGS. 4 and 5;
[0021] [0021]FIGS. 8 through 10 are views explaining a method of fabricating a discrete package according to an aspect of the present invention; and
[0022] [0022]FIG. 11 is a cross-sectional view explaining a method of fabricating a discrete package according to another aspect of the present invention.
[0023] FIGS. 1 - 11 illustrate specific aspects of the invention and are a part of the specification. Together with the following description, the Figures demonstrate and explain the principles of the invention. In the drawings, the thickness of layers and regions are exaggerated for clarity. It will also be understood that when a layer is referred to as being “on” another layer or substrate, it can be directly on the other layer or substrate, or intervening layers may also be present. The same reference numerals in different drawings represent the same element, and thus their descriptions will not be repeated.
DETAILED DESCRIPTION OF THE INVENTION
[0024] The present invention will now be described more fully with reference to the accompanying drawings, in which preferred aspects of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as being limited to the aspects set forth herein. Rather, these aspects are provided so that this disclosure will be thorough and complete and will fully convey the concept of the invention to those skilled in the art.
[0025] [0025]FIGS. 4 and 5 are plan views of upper and lower surfaces, respectively, of a discrete package according to one aspect of the present invention. As shown in FIG. 4, an upper surface of a molding material 450 in the discrete package is exposed. Leads 430 are formed on a side of the discrete package. There is no limit to the number of the leads 430 and the number may be determined according to the type of a semiconductor chip contained in the discrete package. In the aspect of the invention illustrated in FIGS. 4 and 5, the number of leads 430 is set to three for convenience. An upper surface of the discrete package contains a step 455 . As depicted in FIG. 5, a portion of the molding material 450 and a lower surface 410 b of a ceramic layer 410 are exposed at a lower surface of the discrete package.
[0026] [0026]FIG. 6 is a cross-sectional view of a discrete package 600 according to an aspect according to the present invention, taken along the line A-A′ of FIGS. 4 and 5. As illustrated in FIG. 6, the discrete package 600 contains a ceramic layer 410 (which operates as an insulating heat sink) having upper and lower surfaces 410 a and 410 b . The discrete package also contains a lead frame pad 420 formed on the ceramic layer 410 and a semiconductor chip 440 formed on the lead frame pad 420 . The lead frame pad 420 has upper and lower surfaces 420 a and 420 b . Leads 430 are connected to a side of the lead frame pad 420 via a bent portion 435 a . A portion of the ceramic layer 410 , the lead frame pad 420 , and the semiconductor chip 440 are entirely encapsulated by a molding material 450 . Only the lower surface 410 b of the ceramic layer 410 and a portion of the lead 430 are not encapsulated and therefore exposed to the outside the molding material 450 . The discrete package also contains a groove 460 that is formed to pass through a portion of the molding material 450 . When a screw is inserted into the groove 460 , the discrete package 600 can be engaged with an outer heat sink (not shown).
[0027] An adhesive, such as a solder, may be positioned on the upper surface 420 a of the lead frame pad 420 to adhere the semiconductor chip 440 to the lead frame pad 420 . However, the lower surface 420 b of the lead frame pad 420 is directly bonded to the upper surface 410 a of the ceramic layer 410 without an adhesive. In other words, the lead frame pad 420 is bonded to the ceramic layer 410 by using the molding material 450 . When manufacturing the discrete package 600 , a soldering process is not performed between the ceramic layer 410 and the lead frame pad 420 . Thus, there is no need to form a conductive layer pattern on the upper surface 410 a of the ceramic layer 410 for the soldering process. Since the discrete package 600 uses the bare ceramic layer 410 (which can be fabricated at a cost of about three times less than a ceramic layer coated with a conductive layer pattern) as an insulating heat sink, the present invention is able to reduce the manufacturing costs. The ceramic layer 410 is also cheaper than using a DBC substrate, which is itself more expensive than the ceramic layer coated with the conductive layer pattern. Also, the thermal transfer efficiency of the discrete package 600 is higher than that of the discrete package 300 which is insulated using a portion of a molding material. In general, a semiconductor package containing EMC with a filler of 80 wt % (which is used as a molding material) has a thermal transfer efficiency of 2.09 W/m° C. at a temperature of about 25° C. A semiconductor package contains a ceramic layer (made of Al 2 O 3 with 96 degree of purity) has a thermal transfer efficiency of 27 W/m° C. at a temperature of about 25° C.
[0028] [0028]FIG. 7 is a cross-sectional view of a discrete package 700 according to another aspect of the present invention and is taken along the line A-A′ of FIGS. 4 and 5. In this aspect of the invention, elements that are the same as in FIG. 6 are indicated with the same reference numerals and their descriptions will not be repeated.
[0029] As shown in FIG. 7, the discrete package 700 is different from the discrete package 600 in that an epoxy 470 is used to bond the lower surface 420 b of a lead frame pad 420 with the upper surface 410 a of a ceramic layer 410 (which functions as an insulating heat sink). The epoxy 470 is formed to a thickness of about 20 μm and has a thermal transfer efficiency of 4 W/m° C. at a temperature of about 25° C. The discrete package 700 compensates for the disadvantages of the conventional discrete packages and yet has the same advantages as the discrete package 600 .
[0030] Our experiments revealed that the conventional discrete package of FIG. 1 has a thermal resistance of 2.10° C./W while the discrete package 700 of FIG. 7 has a thermal resistance of 0.66° C./W. In other words, the thermal resistance of a discrete package according to the present invention is much lower than that of a comparable conventional package. In these experiments, the respective discrete packages shown in FIGS. 1 and 7 contained a lead frame pad having a thickness of 1.3 mm; an adhesive having a thickness of 20 μm, through which a semiconductor chip was bonded with the lead frame pad; a silicon semiconductor chip having a cross-sectional area of 5.8×4.9 mm 2 and a thickness of 0.3 mm; and an EMC encapsulant having a thickness of 0.4 mm. The discrete package of FIG. 7 contained a ceramic layer having a cross-sectional area of 8.8×72 mm 2 and a thickness of 0.5 mm, and an epoxy having a thickness of 20 μm through which the lead frame pad was bonded with the ceramic layer.
[0031] [0031]FIGS. 8 through 10 illustrate a method of fabricating a discrete package according to one aspect of the present invention. In particular, FIG. 9 is a cross-sectional view of a discrete package according to the present invention and is taken along the line B-B′ of FIG. 8.
[0032] As shown in FIGS. 8 and 9, a semiconductor chip 440 is attached to a chip bonding region of a lead frame pad 420 . A side of the lead frame pad 420 is attached to leads 430 . Although not shown in the drawings, the semiconductor chip 440 may be attached to the lead frame pad 420 using an adhesive, such as a solder. Next, as shown in FIG. 10, wire bonding is performed to electrically connect the semiconductor chip 440 to the leads 430 using wires 480 . Thereafter, as shown in FIG. 6, the structure of FIG. 10 and a ceramic layer 410 are placed in molding equipment and a molding process as known in the art is performed using EMC as the molding material. Then, a general trimming process as known in the art is performed on the resulting structure to obtain a discrete package according to one aspect of the present invention.
[0033] [0033]FIG. 11 is a cross-sectional view illustrating a method of fabricating a discrete package according to another aspect of the present invention. First, a method similar to that explained above (with reference to FIGS. 8 through 10) is carried out. Next, as shown in FIG. 11, a bare ceramic layer 410 is attached to a surface of a lead frame pad 420 using epoxy 470 . The other surface of the lead frame pad 420 is then attached to a semiconductor chip 440 . Thereafter, as shown in FIG. 7, general molding and trimming processes are performed on the resulting structure as known in the art to obtain a discrete package.
[0034] While this invention has been particularly shown and described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.
[0035] As described above, a discrete package according to the present invention uses a ceramic layer as an insulating heat sink, thereby increasing the thermal transfer efficiency of the discrete package. When manufacturing the discrete package, a soldering process is not performed to bond a lead frame pad with the ceramic layer. Therefore, the ceramic layer does not need to be coated with a conductive layer pattern. Consequently, the discrete package according to the present invention contains a bare ceramic layer that is cheaper than a ceramic layer coated with a conductive layer pattern, thereby reducing manufacturing costs.
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Discrete semiconductor packages are described. The discrete package contains: a lead frame pad which has a first surface and a second surface, wherein the second surface which is the opposite surface of the first surface; leads connected to a side of the lead frame pad; a semiconductor chip attached to the first surface of the lead frame pad; a ceramic layer that directly contacts the second surface of the lead frame pad; and a molding material that entirely encapsulates the lead frame pad, the semiconductor chip, and a portion of the ceramic layer, except for a portion of the leads and the second surface of the ceramic layer. Methods for making such discrete packages are also described.
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TECHNICAL FIELD
This disclosure relates to an apparatus for circulating balls. More specifically, this disclosure relates to an apparatus for circulating balls to clean a pipe line.
BACKGROUND ART
The statements in this section merely provide background information regarding an apparatus for circulating balls and may not constitute the related art.
Rust, foreign substances, and the like are accumulated in a pipe line in which a fluid such as water flows as time passes, and thus when the rust, foreign substances, and the like are left, the inside of the pipe line is gradually narrowed to cause a problem that an apparatus or a system is not normally operated.
In order to solve such a problem, recently, techniques of injecting a large number of cleaning balls into a pipe line to be circulated inside the pipe line so as to remove scale accumulated in the pipe line have been applied.
For example, the pipe line may comprise a plurality of tubes arranged in a heat exchanger of a powder plant. The heat exchanger of the powder plant is configured to have plural tubes and is an apparatus which cools water for power generation using sea water or fresh water, and an equipment for cleaning the tubes is referred to as a cleaning equipment.
For cleaning the tubes, elastic cleaning balls are injected into a water box of a condenser in which cooling water flows. Then the cleaning balls are evenly dispersed in the water box and flow into each tube, so as to clean the inside of the tubes.
The cleaning balls thus passing through the tubes are separated from the cooling water by a strainer at an outlet, pass through a ball recirculation pump (hereinafter, simply referred to as a “pump”) and a ball collector again, and then are re-injected into an inlet of the water box through a ball injection nozzle so that continuous tube cleaning is possible.
When an appropriate number of balls are circulated, the condenser tube is kept clean and the thermal conductivity of the tube is maintained in good condition and thus the performance of the condenser or the heat exchanger can be ensured.
Therefore, it is necessary to check whether or not an appropriate number of balls are circulated through the cleaning equipment.
The related art adopts, as a measure of the degree of the cleaning state, a method of checking the collection rate of cleaning balls, that is, how many balls are collected with respect to the number of balls injected into a circulation path. For example, when 1000 cleaning balls are injected into a circulation path, circulated, and then collected, if the number of balls collected is 950, it is determined that better cleaning is carried out compared to a case where 900 balls are collected.
However, in the related art, only the number of balls circulated in the circulation path is considered and thus a problem arise in that whether the balls perform an efficient and effective role of cleaning tubes cannot be actually assessed.
This is because some of the balls are not circulated due to swirl or trapping or loss of the balls caused by the structure of the circulation path and the internal shape of the circulation path, and due to these balls, it is meaningless to consider only the number of circulating balls for evaluating the degree of cleaning.
The related art has a problem in that in the above-described example, if 50 to 100 balls are not normally circulated or lost, it is assumed that 900 to 950 balls are normally circulated and if 900 balls sufficiently perform a role of cleaning the tubes while being circulated in the circulation path, there is no reason for evaluating that cleaning is poor compared to a case where 950 balls are circulated.
On the other hand, the cleaning equipment adopts a counter as means for checking whether or not an appropriate number of balls are circulated through the cleaning equipment. The counter is a device for counting the number of cleaning balls circulating inside the circulation path.
A conventional counter (Korean Patent Publication No. 10-2005-0008214) has a structure in which a transparent passage pipe is arranged in the middle of a circulation path and a sensor is arranged on the outside of the passage pipe and emits infrared rays to detect balls flowing inside the passage pipe and count the number of the balls.
However, in the conventional structure, since balls are aggregated and pass together through the passage pipe, many balls may be counted as one by being detected at the same time and thus there is a problem of erroneous counting of the number of the cleaning balls.
SUMMARY OF INVENTION
Technical Problem
An object of an embodiment of the present invention is to provide a ball circulating apparatus for cleaning a pipe line which adopts a new method for checking the degree of pipe cleaning so as to solve the problems in the related art.
Another object of the embodiment of the present invention is to provide a counter capable of more precisely counting the number of cleaning balls by preventing plural balls from being aggregated and passing together through a passage pipe.
Solution to Problem
According to an embodiment of the present invention, an apparatus for circulating balls may include a circulation path for circulating a fluid and balls. The circulation path may include a cooling water tube of a heat exchanger.
The apparatus may include a pump arranged on the circulation path for pumping the fluid.
Further, the apparatus may include a counter for counting time and the balls in relation to the circulation of the balls.
As one embodiment, the counter may count the number of balls passing therethrough for a predetermined period of time. The predetermined period of time may be a period of time for one circulation of the balls (hereinafter referred to as a “ball circulation period”) during which the balls make one circulation through the circulation path.
The counter may calculate a rate (hereinafter referred to as a “ball period circulation rate”) which is obtained by dividing the number of balls counted during the ball circulation period by the number of balls input into the circulation path.
As an exemplary embodiment, the counter may count the time during which a predetermined number of balls make a predetermined number of circulations through the circulation path.
The counter may count the balls up to the number which is the same as the number of the balls input into the circulation path and count time which is taken for the counted number of balls to make a predetermined number of circulations.
The predetermined number of balls may be the number of balls which is actually circulated in the circulation path.
The predetermined number of balls may be smaller than the number of balls input into the circulation path.
The counter may be configured to count time which is taken for a predetermined number of balls to pass through the counter.
The counter may count time which is taken for the number of balls input into the circulation path to pass through the counter.
The predetermined number may be the number of balls which is actually circulated in the circulation path.
The predetermined number may be smaller than the number of balls input into the circulation path.
The ball may be made of an elastic material.
The diameter of the ball may be larger than the inner diameter of the cooling water tube.
The counter may include a first passage pipe in which the balls and the fluid flow.
Further, the counter may include a second passage pipe arranged in the first passage pipe.
Further, the apparatus for circulating balls may include a screen arranged in the first passage pipe and having an inclined surface for guiding the balls flowing in the first passage pipe to the second passage pipe.
Further, the apparatus may include a sensor for counting the number of balls flowing in the second passage pipe.
The first passage pipe and the second passage pipe may have cylindrical shapes, respectively.
The first passage pipe may be configured to allow the fluid and the balls to flow in the same direction.
The second passage pipe may be configured to allow the fluid and the balls to flow in the same direction.
The first passage pipe may have connection portions on both sides. Through the connection portions, the pipe can be connected with the circulation path.
The diameter of the second passage pipe may be larger than the diameters of the balls.
The screen may comprise a plurality of holes having such sizes that the balls are unable to pass therethrough.
The total cross-sectional area of the flow path formed by the plurality of holes may be larger than the cross-sectional area of the flow path formed by the second passage pipe.
The screen may have a funnel shape.
The sensor may have a light emitting portion. Further, the sensor may have a light receiving portion.
At least a part of the first passage pipe may be transparent so that the light from the light emitting portion can be emitted to the light receiving portion. Further, the second passage pipe may be transparent at a portion corresponding to the transparent portion of the first passage pipe.
Effects of Invention
As described above, an embodiment of the present invention provides a new method for more effectively determining a degree of pipe cleaning by considering time and the number of balls when cleaning a pile line using cleaning balls.
An embodiment of the present invention is advantageous in that the number of cleaning balls circulating in the circulation path can be exactly counted.
Further, it is advantageous that a ball counter may be formed in a simpler structure and thus the durability of the counter can be improved and the manufacturing cost can be lowered.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 illustrates an apparatus for circulating balls according to an embodiment of the present invention.
FIG. 2 is a conceptual view illustrating a ball counter according to an embodiment (first embodiment) of the present invention.
FIG. 3 is a perspective view illustrating a counter according to another embodiment (second embodiment) of the present invention in which a second passage pipe and a screen is combined.
FIG. 4 is a cross-sectional view illustrating a state in which the counter according to the second embodiment of the present invention is connected with a circulation path.
FIG. 5 is a cross-sectional view illustrating a state in which balls flow into the second passage pipe of the counter according to the second embodiment of the present invention connected with the circulation path.
FIG. 6 is a schematic view illustrating the configuration of a conventional counter.
FIGS. 7( a )-7( b ) are schematic views illustrating the configuration of an improved conventional counter.
FIG. 8 is a view illustrating an apparatus for recirculating balls according to still another embodiment of the present invention.
DESCRIPTION OF EMBODIMENTS
An apparatus for circulating balls according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. The present invention may be embodied in various forms and thus only a few embodiments will be described in detail in the specification with the drawings. However, it should be understood that the description of the embodiments is not intended to limit the present invention. In the description of the drawings, the same reference numbers are used the same components or parts. In the accompanying drawings, some parts are illustrated in an enlarged scale or a smaller scale to show in detail or schematically.
In addition, the terms of “first” and “second” may be used for description of various elements. However, these elements are not limited to these terms. The terms are used only for the purpose of distinguishing one element from the other. For example, within the range not departing from the scope of the present invention, a first element may be referred to as a second element and the second element may be referred to as the first element in the same manner.
FIG. 1 is a view schematically illustrating the configuration of an apparatus for circulating balls ( 1 ) according to an embodiment of the present invention and a partially enlarged view thereof. In the drawing, the apparatus is combined with a heat exchanger ( 2 ) of a power plant to be used as a cleaning apparatus for the heat exchanger.
The apparatus for circulating balls ( 1 ) according to the embodiment of the present invention may include a circulation path ( 3 ), a pump ( 4 ), a counter ( 5 ), and a strainer ( 8 ). The circulation path ( 3 ) includes a cooling water tube ( 11 ) of the heat exchanger ( 2 ) and a fluid and balls ( 7 ) are circulated therein. The strainer ( 8 ) may be arranged on the circulation path ( 3 ). The pump ( 4 ) may be arranged on the circulation path ( 3 ) and pumps the fluid to be circulated. The counter ( 5 ) is arranged on the circulation path ( 3 ) and counts the number of balls ( 7 ) circulating in the circulation path ( 3 ).
The ball ( 7 ) may be formed with an elastic material. For example, the ball is made of silicone, sponge or rubber.
The circulation path ( 3 ) may include an inlet pipe ( 10 ), an outlet pipe ( 12 ), the cooling water tube ( 11 ), and a circulation pipe ( 13 ). The strainer ( 8 ) is arranged on the outlet pipe ( 12 ) and plays a role of separating the balls ( 7 ) and the fluid in the outlet pipe ( 12 ) and moving the balls and fluid to the circulation pipe ( 13 ).
The heat exchanger ( 2 ) may include a main body ( 9 ) and the cooling water tube ( 11 ). The inlet pipe ( 10 ) is connected to the main body ( 9 ) on the upstream side and the outlet pipe ( 12 ) is connected to the main body on the downstream side. Inside the main body ( 9 ) of the heat exchanger ( 2 ), plural cooling water tubes ( 11 ) to be connected with the inlet pipe ( 10 ) and the outlet pipe ( 12 ) may be arranged.
For example, cooling water may be sea water or fresh water. The cooling water is introduced into the main body ( 9 ) through the inlet pipe ( 10 ), then passes through the plural cooling water tubes ( 11 ) in the main body ( 9 ), and is discharged to the outside through the outlet pipe ( 12 ).
The fluid may be circulating water which is not introduced or discharged to the heat exchanger ( 2 ) as a part of the cooling water and continuously circulated through the circulation path ( 3 ).
The fluid as a part of the cooling water flows out from the outlet pipe ( 12 ) through the strainer ( 8 ) connected to the middle of the outlet pipe ( 12 ), passes through the circulation pipe ( 13 ), and then is introduced into the cooling water tube ( 11 ) through the inlet pipe ( 10 ). That is, the fluid circulates along the circulation path ( 3 ). The fluid may circulate in the circulation path ( 3 ) with the balls ( 7 ).
The counter ( 5 ) counts time and the number of balls ( 7 ) circulating in the circulation path ( 3 ) to show whether or not the inside of the cooling water tube ( 11 ) is sufficiently cleaned. The method of determining the degree of cleaning using the counter ( 5 ) and the structure of the counter ( 5 ) will be described later.
The method of cleaning the cooling water tube ( 11 ) will be described. A large number of balls ( 7 ) are injected into the circulation path ( 3 ) through an injection portion (not shown). The fluid is circulated in the circulation path ( 3 ) by the pump ( 4 ) and the large number of balls ( 7 ) are circulated with the fluid. The balls ( 7 ) and the fluid flow along the circulation pipe ( 13 ) and flow into the inlet pipe ( 10 ). The cooling water introduced from the outside, the balls ( 7 ) and the fluid introduced through the circulation path ( 3 ) are joined in the inlet pipe ( 10 ). The cooling water, the balls ( 7 ) and the fluid joined in the inlet pipe ( 10 ) are introduced into the main body ( 9 ) of the heat exchanger. In the main body ( 9 ) of the heat exchanger, a large number of cooling water tubes ( 11 ) are arranged. The diameter of the ball passing through the cooling water tube ( 11 ) is larger than the inner diameter of the cooling water tube ( 11 ). Depending on embodiments, the diameter of the ball ( 7 ) may be larger than the inner diameter of the cooling water tube ( 11 ) by 1 mm to 2 mm. The ball ( 7 ) may be formed with an elastic material. Thus, the ball ( 7 ) becomes elastic as passing though the tube ( 11 ). That is, when the ball ( 7 ) passes through the tube ( 11 ), the ball is tightly fitted to the inner surface of the tube ( 11 ) and scrapes out scale accumulated inside the tube in a state of being in tight contact with the inner surface of the tube ( 11 ) (refer to the partially enlarged view of FIG. 1 ). Such a structure has an effect of easily removing scale that is accumulated and solidified inside the tube ( 11 ).
The balls ( 7 ) passing through the tube ( 11 ) moves to the outlet pipe ( 12 ) again with the cooling water and fluid. The cooling water is discharged to the outside by the outlet pipe ( 12 ) and the fluid and the balls ( 7 ) are moved to the circulation pipe ( 13 ) through the strainer ( 8 ) arranged in the middle of the outlet pipe ( 12 ) to be recirculated in the circulation path ( 3 ).
The method of determining the degree of tube cleaning using the counter ( 5 ) will be described.
The apparatus for circulating balls ( 1 ) according to the embodiment of the present invention provides a new method for determining whether or not the cooling water tube ( 11 ) is sufficiently cleansed.
First, the related art for determining the degree of cleaning of the tube ( 11 ) will be described. In the related art, a method of determining the degree of cleaning based on the collection rate of the cleaning balls ( 7 ), that is, the number of balls collected with respect to the number f balls injected into the circulation path ( 3 ) is adopted. For example, if 1000 cleaning balls ( 7 ) are injected into the circulation path ( 3 ), circulated, and then only 950 balls are collected, it is evaluated that better cleaning is carried out compared to a case where 900 balls are collected. In this manner, the degree of cleaning is assessed.
That is, in the related art, the degree of cleaning is determined based on the number of collected balls ( 7 ).
A conventional method of the related art is based on a factual result that the number of collected balls becomes smaller than the number of the balls ( 7 ) input into the circulation path ( 3 ) due to the causes such as swirl or trapping or loss of the balls caused by the structure and the inner shape of the circulation path ( 3 ). The conventional method is based on a premise that better pipe cleaning is carried out in a case where a large number of balls ( 7 ) are circulated in the circulation path ( 3 ) than a case where a small number of balls ( 7 ) are circulated.
However, the amount of balls not circulated and lost due to the cases is generally constant. Thus, counting the number of balls ( 7 ) excluding the lost ones is not a good method for evaluating the degree of cleaning.
That is, in the above example, when about 50 to 100 balls ( 7 ) are not normally circulated or lost, and so 900 to 950 balls ( 7 ) are circulated, if 900 circulating balls sufficiently perform a function for cleaning the tube ( 11 ), then there is no reason for evaluating that the cleaning with the 900 balls is poor compared to a case where 950 balls are circulated. In this regard, the conventional method is problematic.
The conventional method is meaningful only in a case where the number of balls ( 7 ) collected is remarkably decreased compared to the number of balls ( 7 ) input.
Particularly, as the difference between the number of balls injected and the number of balls collected is small, it is not appropriate to use a comparison only with the numbers of balls ( 7 ) or a collection rate for precisely evaluating the degree of cleaning. Thus, the related art does not provide an appropriate method for evaluating the cleaning performance.
The apparatus for circulating balls ( 1 ) according to the embodiment of the present invention provides a measure using not only the number of balls but also the concept of time for evaluating the degree of cleaning.
The counter ( 5 ) of the apparatus for circulating balls ( 1 ) according to the embodiment of the present invention can count time and the number of balls ( 7 ) for determining the degree of cleaning in relation to the circulation of the balls ( 7 ). The counter ( 5 ) does not count only the number of balls ( 7 ). The counter ( 5 ) includes a control part (not shown). The counter ( 5 ) can count the time for the number of balls passing therethrough by the control part.
The counter ( 5 ) can count the number of balls passing the counter ( 5 ) for a predetermined period of time. For example, the counter ( 5 ) can count the number of balls ( 7 ) passing through the counter for one hour. In this case, as the counted result value (number of balls) is higher, it can be evaluated that the degree of cleaning is high.
The related art has a problem in that it is inconvenient to count the number of balls ( 7 ) since the circulating balls needs to be collected for the counting.
However, according to the embodiment of the present invention, the number of balls ( 7 ) circulating in the circulation path ( 3 ) can be directly counted by the counter ( 5 ) and thus it is easy to evaluate the degree of cleaning.
The predetermined period of time may be a ball circulation period. The ball circulation period may be defined as the period of time which is taken for the balls to make one circulation in the circulation path ( 3 ).
For example, the ball circulation period can be obtained by a method of measuring the time for one ball ( 7 ) in the circulation path ( 3 ) to take for making one circulation. In a case of injecting a large number of balls ( 7 ) into the circulation path ( 3 ), the time can be measured by changing the color of some ( 7 ) of the injected balls ( 7 ) or attaching a sensor to some of the balls. When the large number of balls ( 7 ) are circulated in the circulation path, the time for aligning the balls ( 7 ) in the ball collector (not shown), that is, the time for the balls ( 7 ) staying in the ball collector is added the time for one ball ( 7 ) making one circulation in the circulation path to obtain the circulation period for the total balls ( 7 ). Further, when the velocity of the fluid is the same as the circulation speed of the ball ( 7 ), ball circulation period can be measured in such a manner that the velocity of the fluid circulating in the circulation path ( 3 ) is measured and then the length of the circulation path ( 3 ) is divided by the velocity of the fluid.
The degree of tube cleaning can be evaluated by calculating a ball period circulating rate. The ball period circulation rate is a value obtained by dividing the number of balls ( 7 ) counted during the ball circulation period by the number of balls ( 7 ) injected into the circulation path ( 3 ). The number of balls ( 7 ) passing through the counter ( 5 ) is counted during the ball circulation period and the number is divided by the number of balls ( 7 ) injected into the circulation path ( 3 ) to calculate the ball period circulation rate. As the ball period circulation rate is high, the degree of cleaning is high.
According to another embodiment of the present invention, the counter ( 5 ) may count the time for a predetermined number of balls ( 7 ) making a predetermined number of circulations in the circulation path ( 3 ).
Here, the predetermined number of circulations is a preset number. For example, the counter ( 5 ) may be configured to count the time for all the circulating balls ( 7 ) making n number of circulations in the circulation path ( 3 ) (n is a positive integer).
Here, the predetermined number of balls may be the number of balls ( 7 ) input into the circulation path ( 3 ). Here, the number of the input balls ( 7 ) may be the number of balls ( 7 ) injected into the circulation path ( 3 ). That is, the counter can count the time which is taken for the total number of input balls ( 7 ) to make the predetermined number of circulations. For example, when 1000 balls ( 7 ) are input, the time for the ball counted as 1000 th making one circulation can be counted.
That is, in the above example, as a result of injecting 1000 balls ( 7 ) and circulating, in a first case in which 950 balls ( 7 ) are circulated, the counter ( 5 ) counts the number from a first ball ( 7 ) and counts a 950 th ball ( 7 ) as 950, and then, counts as a 951 th ball the first ball ( 7 ) which returns to the counter ( 5 ) after having made one circulation in the circulation path ( 3 ). In this manner, a 50 th returned ball ( 7 ) is counted as a 1000 th ball. In a second case in which 1000 balls ( 7 ) are injected and only 900 balls are circulated, the counter ( 5 ) counts the number from a first ball ( 7 ) and counts a 900 th ball as 900 and then counts the first ball ( 7 ) which returned to the counter ( 5 ) as a 901 th ball. In this manner, a 100 th returned ball ( 7 ) is counted as a 1000 th ball.
In both cases, even when 1000 balls, which is the number of input balls, are counted, the number of balls actually not circulated (50 in the first case and 100 in the second case) is counted and thus there is a difference between one circulation periods of the two cases. Therefore, in a case where a predetermined number is the number of balls ( 7 ) injected into the circulation path ( 3 ), it is meaningful.
Comparing the both cases, the counting time in the second is longer than the time in the first case. That is, the time for the balls ( 7 ) making one circulation in circulation path ( 3 ) is shorter in the first case than in the second case. Therefore, it can be evaluated that the first is better.
In addition, the predetermined number may be the number of balls ( 7 ) actually circulating in the circulation path ( 3 ). When there are balls not circulating in the circulation path due to swirl or trapping or loss of the balls caused by the structure of the circulation path and the internal shape of the circulation path, the time for the number of balls ( 7 ) actually circulating in the circulation path making a set number of circulations can be counted.
Further, the predetermined number may be smaller than the number of balls ( 7 ) injected into the circulation path ( 3 ). For example, the time for 100 balls making one circulation in the circulation path can be counted.
According to another embodiment of the present invention, the counter ( 5 ) may count the time for a predetermined number of balls ( 7 ) passing through the counter. For example, the counter can count the time for ( 5 ) a preset 1000 balls passing through the counter. In this case, as the counted result value (time) is small, the degree of cleaning is evaluated as high.
The structure of the counter ( 5 ) will be described.
FIG. 2 is a conceptual view illustrating the ball counter ( 5 ) according to an embodiment (first embodiment) of the present invention. A drawing of the control portion is omitted. As shown in the drawing, the counter ( 5 ) may include a first passage pipe ( 21 ) into which the large number of balls ( 7 ) and a fluid flow, a second passage pipe ( 22 ) arranged in the first passage pipe ( 21 ), a screen ( 23 ) arranged in the first passage pipe ( 21 ), and a sensor ( 24 ) for counting the number of balls ( 7 ) flowing in the second passage pipe ( 22 ). The arrow indicated by a dotted line in FIG. 2 represents a flowing direction of the fluid and the arrow indicated by a solid line in FIG. 2 represents a flowing direction of the ball ( 7 ).
The first passage pipe ( 21 ) may have a hollow cylindrical shape. In addition, the first passage pipe may be transparent so that the light emitted from the sensor ( 24 ), which will be described later, can pass through. The both ends of the first passage pipe ( 21 ) can be provided with connection portions so that the counter can be connected with the circulation path ( 3 ) in which the fluid flows.
The second passage pipe ( 22 ) may have a hollow cylindrical shape. In addition, a portion of the second passage pipe located correspondingly to the transparent portion of the first passage pipe ( 21 ) may be transparent so that the light emitted from the sensor ( 24 ), which will be described later, can pass through. The diameter of the second passage pipe ( 22 ) is larger than the diameter of the ball ( 7 ). Thus, the ball ( 7 ) can smoothly pass through the second passage pipe with the fluid. That is, the ball ( 7 ) can move with the fluid without a decrease in velocity when passing through the second passage pipe ( 22 ). The diameter of the second passage pipe ( 22 ) has a size in which two balls ( 7 ) are unable to pass at the same time. The length of the second passage pipe ( 22 ) may be longer than the length of the first passage pipe ( 21 ).
In the screen ( 23 ), a plurality of holes ( 25 ) may be formed. Here, the size of the hole is sufficiently small such that the ball ( 7 ) is unable to pass. The total cross-sectional area of the flow path of the plurality of holes ( 25 ) may be larger than the flow path cross-sectional area of the second passage pipe ( 22 ). Therefore, the amount of fluid flowing in the first passage pipe ( 21 ) is larger in the screen ( 23 ) than in the second passage pipe ( 22 ). As a result, the flowing of the fluid in the first passage pipe ( 21 ) is smooth. The holes ( 25 ) may be formed in various shapes such as a rectangular shape or a cylindrical shape. Any shaped holes can be used as the holes ( 25 ) in this embodiment, only if the holes are configured to allow for the fluid to pass through but not for the balls.
One side of the screen ( 23 ) is connected to the first passage pipe ( 21 ) and the other side thereof is connected to the second passage pipe ( 22 ). Depending on embodiments, the screen ( 23 ) may be integrally formed with the second passage pipe ( 22 ). Further, the first passage pipe ( 21 ) may be integrally formed with the screen ( 23 ). The diameter of the portion of the screen connected to the first passage pipe ( 21 ) is larger than the diameter of the portion of the screen connected to the second passage pipe ( 22 ). The screen ( 23 ) may have a funnel shape. The screen ( 23 ) has an inclined surface. That is, the screen has a surface inclined in the length direction of the first passage pipe ( 21 ) or the second passage pipe ( 22 ). However, the contour from the portion connected to the first passage pipe ( 21 ) to the portion connected to the second passage pipe ( 22 ) may not be necessarily linear. The inclined surface perform a role of guiding the balls ( 7 ) flowing in the first passage pipe ( 21 ) to the center of the second passage pipe ( 22 ). That is, the fluid flows through the spaces ( 25 ) formed on the inclined surface and the balls and the fluid flow through the second passage pipe ( 22 ) connected to the center of the screen ( 23 ).
After the balls ( 7 ) pass through the second passage pipe ( 22 ), the balls keep circulating along the circulation path ( 3 ).
The sensor ( 24 ) includes a light emitting portion ( 24 a ) and a light receiving portion ( 24 b ). In addition, the sensor may be arranged in the first passage pipe ( 21 ) or on the outside of the first passage pipe. When the sensor is arranged in the first passage pipe ( 21 ), it is preferable to have waterproofing means. The light emitting portion ( 24 a ) and the light receiving portion ( 24 b ) are arranged on the sides of the second passage pipe ( 22 ) so as to face each other with the second passage pipe ( 22 ) interposed therebetween.
The light emitting portion ( 24 a ) can emit light. The light receiving portion ( 24 b ) can detect the light emitted from the light emitting portion ( 24 a ). As for the light, infrared rays may be used depending on embodiments. The light emitted from the light emitting portion ( 24 a ) may pass through the transparent portion of the first passage pipe ( 21 ) or the second passage pipe ( 22 ) to be incident into the light receiving portion ( 24 b ).
Depending on embodiments, in a case where the ball ( 7 ) is made of a material that light cannot pass through, the light receiving portion ( 24 b ) can detect light only when the balls ( 7 ) do not pass though the second passage pipe ( 22 ). When the light receiving portion ( 24 b ) detects light, a detection signal is sent to the control portion. The control portion counts the number of balls ( 7 ) passing though the second passage pipe ( 22 ) by the detection signal transmitted by the sensor ( 24 ). The control portion that counts the number of balls ( 7 ) and the wiring connecting the control portion and the sensor ( 24 ) are known techniques and the description will be omitted.
FIG. 3 is a perspective view illustrating the counter ( 5 ) according to another embodiment (second embodiment) of the present invention in which the second passage pipe ( 22 ) and the screen ( 23 ) is combined. The sensor ( 24 ) is not shown. In FIG. 3 , the material of the second passage pipe ( 22 ) is transparent. As shown in the drawing, the screen ( 23 ) includes a flange portion ( 31 ), a strainer portion ( 32 ), and a second passage pipe connecting portion ( 33 ). The first flange portion ( 31 ) comprises a plurality of bolt holes ( 34 ) to connect the first flange portion ( 31 ) to the first passage pipe ( 21 ) and the circulation path ( 3 ). The strainer portion ( 32 ) comprises a plurality of spokes or bars ( 35 ) extended from the second passage pipe connecting portion ( 33 ) to the first flange portion ( 31 ). The holes ( 25 ) are formed between the bars ( 35 ). The second passage pipe connecting portion ( 33 ) has a cylindrical shape and has a plurality of bolts ( 36 ) screwed on the circumferential surface so as to be combined with the second passage pipe ( 22 ). Depending on embodiments, the second passage pipe ( 22 ) may be integrally formed with the screen ( 23 ). In addition, depending on embodiments, the second passage pipe ( 22 ) and the screen ( 23 ) may be integrally formed with the first passage pipe ( 21 ).
FIG. 4 is a cross-sectional view illustrating a state in which the counter ( 5 ) according to the second embodiment of the present invention is connected with the circulation path ( 3 ). The sensor ( 24 ) is not shown in the drawing. As shown in the drawing, the combined body of the second passage pipe ( 22 ) and the screen ( 23 ) is connected to the first passage pipe ( 21 ) and the both ends of the first passage pipe ( 21 ) are connected to the circulation path ( 3 ). The both ends of the circulation path ( 3 ) are bent in L shape and the both ends of the first passage pipe ( 21 ) are also bent in L shape. When FIG. 4 is viewed, the first passage pipe ( 21 ), the flange portion ( 31 ) of the screen ( 23 ), and the pipe are sequentially connected in the connection portion ( 37 ) on the right side and screwed by bolts ( 38 ). However, in another embodiment, instead of being the both ends of the first passage pipe ( 21 ) in L shape, a pair of connection portions for connection with the circulation path ( 3 ) may be separately attached.
FIG. 5 is a cross-sectional view illustrating a state in which the balls ( 7 ) flow into the second passage pipe ( 22 ) of the counter ( 5 ) according to the second embodiment of the present invention connected with the circulation path ( 3 ). The sensor ( 24 ) is not shown in the drawing. The plural rows of balls ( 7 ) flowing disorderedly are guided to the center through the inclined surface of the screen ( 23 ) and pass through the second passage pipe ( 22 ).
FIG. 6 is a schematic view illustrating the configuration of a conventional counter ( 40 ). As shown in the drawing, the conventional counter ( 40 ) includes a housing ( 41 ), detecting means ( 42 ), and cleaning balls ( 7 ). The operation principle is that the detecting means ( 42 ) positioned on the outside of the housing ( 41 ) emits infrared rays to the large number of cleaning balls ( 7 ) passing through the housing ( 41 ) to count the number of cleaning balls ( 7 ).
In the conventional counter ( 40 ) (refer to FIG. 6 ), since the plural balls can be aggregated and pass through the housing ( 41 ), the detecting means ( 42 ) may detect a plurality of balls ( 7 ) at the same time and thus erroneous counting of the number of balls ( 7 ) occurs. However, the counter ( 5 ) according to the embodiment of the present invention has effect of exactly counting the number of balls since the balls ( 7 ) pass through the second passage pipe ( 22 ) one by one.
FIG. 7 is a schematic view illustrating the configuration of an improved conventional counter ( 50 , Korean Patent Publication No. 10-2006-0028915). FIG. 7( a ) is a perspective view and FIG. 7( b ) is a cross-sectional view showing an operation example. As shown in the drawing, the improved conventional counter ( 50 ) includes a housing ( 51 ), arrangement means ( 56 ) for arranging plural cleaning balls ( 7 ) flowing into the housing ( 51 ), rate control means ( 61 ) composed of flow rate control plates ( 60 a , 60 b ) in which a hole ( 57 ) through which the cleaning balls ( 7 ) can pass one by one and a large number of bypass holes ( 58 ) are formed, and detecting means ( 59 a , 59 b ) for detecting the large number of cleaning balls ( 7 ) passing arranged by the arrangement means.
The arrangement means ( 56 ) is composed of plural arrangement plates ( 54 , 55 ) which are separated from each other in the housing ( 51 ) and have plural holes ( 53 ) through which the cleaning balls ( 7 ) can pass, and the holes ( 53 ) formed in the two adjacent arrangement plates ( 54 , 55 ) are alternately arranged.
The detecting means ( 59 a , 59 b ) includes a counter tube ( 52 ) formed such that the large number of cleaning balls ( 7 ) passing through the arrangement means ( 56 ) pass through the tube, first and second cut portions formed in the counter tube ( 52 ) in the travelling direction of the cleaning ball ( 7 ) with a predetermined positional difference, first and second detection plates ( 64 , 65 ) in which one end is fixed to the outer surface of the counter tube ( 52 ) and the other end is positioned in the first or second cut portion and in contact with the cleaning balls ( 7 ) passing through the counter tube ( 52 ) to be elastically deformed, and first and second sensor ( 62 , 63 ) for generating a signal to detect the deformation of the first and second detection plates ( 64 , 65 ).
In the improved conventional counter ( 50 ) (refer to FIG. 7 ), the diameter of the counter tube ( 52 ) is small and thus a foregoing ball ( 7 ) is pushed by the following ball ( 7 ). Thus, the balls ( 7 ) are in tight contact with one another and pass through the counter tube ( 52 ) and thus there is a disadvantage that the balls ( 7 ) have to be counted only by a contact sensor. However, the diameter of the second passage pipe ( 22 ) is sufficiently larger than the diameter of the ball ( 7 ) in the counter ( 5 ) according to the embodiment of the present invention, and thus there is an advantage that a non-contact sensor can be used.
In the counter ( 5 ) according to the embodiment of the present invention, the balls ( 7 ) are guided to the center of the screen ( 23 ) along the inclined surface and pass thought the second passage pipe ( 22 ) one by one. The balls ( 7 ) are not pushed by water pressure to pass through the second passage pipe ( 22 ). One ball ( 7 ) enters the second passage pipe ( 22 ) and then another ball ( 7 ) enters the second passage pipe ( 22 ). The balls are moved by the flowing of the fluid and the following ball ( 7 ) does not push the foregoing ball ( 7 ). Thus, there is a low possibility of the balls ( 7 ) being aggregated while passing the passage pipe. Therefore, as in the improved conventional counter ( 50 ) (refer to FIG. 7 ), there is no need to arrange separate arrangement means ( 56 ) and plural detecting means ( 59 a , 59 b ), which will be described later. As a result, the structure of the product is simple and thus the durability of the product is good and the manufacturing cost can be reduced.
Further, in the improved conventional counter ( 50 ) (refer to FIG. 7 ), the rate control means ( 61 ) and the arrangement means ( 56 ) are connected to each other in a direction perpendicular to the length direction of the counter tube ( 52 ) and the flowing direction of the fluid and thus the flowing of the fluid and the balls ( 7 ) is poor. However, in the counter ( 5 ) according to the embodiment of the present invention, the screen ( 23 ) having the inclined surface in which a large number of spaces ( 25 ) are formed is formed or arranged and thus the flowing of the fluid and the balls ( 7 ) is smooth.
The first and second detection plates ( 64 , 65 ) in the improved conventional counter ( 50 ) (refer to FIG. 7 ) transmits the detection signal to the first and second sensors ( 62 , 63 ) by being elastically deformed while being in direct contact with the balls ( 7 ) passing through the counter tube ( 52 ). Accordingly, since the detection plates ( 64 , 65 ) are in direct contact with the large number of balls ( 7 ), there is a problem of the detecting means ( 59 a , 59 b ) being easily broken and the material of the ball ( 7 ) is typically a material that is easily worn out such as silicone or sponge and thus there is a problem of the ball ( 7 ) being easily worn out. However, in the counter ( 5 ) according to the embodiment of the present invention, the sensor ( 24 ) is not in direct contact with the ball ( 7 ) and thus there is an advantage that the ball ( 7 ) is worn out or the sensor ( 24 ) is not broken by the contact.
The counter ( 5 ) according to the embodiment of the present invention has an advantage of more exactly counting the number of balls ( 7 ). In addition, since the counter includes the control portion, not only the number of balls but also time can be counted.
FIG. 8 is a view illustrating an apparatus for circulating balls ( 160 ) according to still another embodiment of the present invention.
As shown in the drawing, the apparatus for circulating balls ( 160 ) includes an air compressor ( 161 ) for generating compressed air of high pressure, an injector ( 162 ) for accommodating a fluid (w) and discharging the fluid (w) to a heat exchanger of a powder plant by supplying of the high pressured compressed air discharged from the air compressor ( 161 ), a ball collector ( 163 ) for accommodating a large number of cleaning balls ( 107 ) and discharging the cleaning balls ( 107 ) to the heat exchanger of the power plant with the high pressure fluid discharged from the injector ( 162 ), and a ball strainer ( 165 ) for returning the balls ( 107 ) discharged from the ball collector ( 163 ) and passing through a heat exchanger ( 164 ) to the ball collector ( 163 ).
A first solenoid valve ( 167 ) is arranged in a pipe ( 166 ) which connects the air compressor ( 161 ) and the injector ( 162 ), a first check valve ( 171 ) is arranged in a pipe ( 170 ) which connects the ball collector ( 163 ) and an inlet pipe ( 169 ) in a heat exchanger system, and a second check valve ( 172 ) is arranged in a pipe ( 174 ) which connects the ball strainer ( 165 ) and the ball collector ( 163 ). In addition, in the injector ( 162 ), a drain pipe ( 175 ) is arranged so as to discharge the high pressure compressed air in the injector ( 162 ) to the outside, and a second solenoid valve ( 168 ) is arranged in the middle of the drain pipe ( 175 ).
A control portion ( 173 ) controls the opening/closing period of the first and second solenoid valves ( 167 , 168 ) so that the apparatus for circulating balls ( 160 ) is operated smoothly.
Hereinafter, the operation of the apparatus for circulating balls ( 160 ) will be described. In an initial state in which both the first and second solenoid valves ( 167 , 168 ) are closed, the large number of cleaning balls ( 107 ) are gathered in the ball collector ( 163 ), and the injector ( 162 ) is filled with the fluid (w), when the air compressor ( 161 ) is operated by the control portion ( 173 ) and the first solenoid valve ( 167 ) is opened, high pressure air flows into the injector ( 162 ) from the compressor ( 161 ) to pressurize the fluid (w). The applied pressure is transmitted into the ball collector ( 163 ) and the large number of cleaning balls ( 107 ) in the ball collector ( 163 ) are injected into the inlet of the heat exchanger ( 164 ) though the first check valve ( 171 ) and the pipe ( 170 ). When a preset period of time in which the cleaning balls ( 107 ) are injected into the heat exchanger ( 164 ) from the ball collector ( 163 ) has passed, the control portion ( 173 ) converts the state of the first solenoid valve ( 167 ) into the closed state. The large number of cleaning balls ( 107 ) injected into the heat exchanger ( 164 ) remove scale fixed on the wall surface while being in tight contact with the wall surface of the pipe of the heat exchanger ( 164 ). The fluid passing through the heat exchanger ( 164 ) passes through the outlet pipe and then is discharged to the outside though the ball strainer ( 165 ), and the cleaning balls ( 107 ) pass through the ball strainer ( 165 ) and the pipe ( 174 ) and are recirculated through the second check valve ( 172 ) and the first check valve ( 171 ). When the cleaning is completed, the control portion ( 173 ) closes the second check valve ( 172 ) and the cleaning balls ( 107 ) stand by in a stationary state at the inlet of the second check valve ( 172 ) through the pipe ( 174 ). When the preset period of time in which all the cleaning balls ( 107 ) can pass through the heat exchanger ( 164 ) has passed, the control portion ( 173 ) opens the second solenoid valve ( 168 ) to discharge the high pressure air in the injector ( 162 ) to the outside through the drain pipe ( 175 ). At the same time, the cleaning balls ( 107 ) are returned into the ball collector ( 163 ) through the second check valve ( 172 ) and the injector ( 162 ) is refilled with the fluid through the ball collector ( 163 ). When the preset period of time in which the ball collector ( 163 ) can collect all the cleaning balls ( 107 ) has passed, the control portion ( 173 ) closes the second solenoid valve ( 168 ) and thus the state of the apparatus for circulating balls ( 160 ) is returned to the initial state.
In the apparatus for circulating balls ( 160 ), the counter ( 105 ) may be arranged in the middle of the pipe ( 174 ) connecting the outlet of the ball strainer ( 165 ) and the inlet of the second check valve ( 172 ) depending on embodiments.
While the present invention has been described with reference to some embodiments in the detailed description of the present invention, it will be understood by those skilled in the art that various corrections and changes may be made therein without departing from the scope of the invention.
REFERENCE NUMERALS
1 : Apparatus for recycling balls according to embodiment
2 : Heat exchanger
3 : Circulation path
4 : Pump
5 : Counter
7 : Ball
8 : Strainer
11 : Cooling water tube
21 : First passage pipe
22 : Second passage pipe
23 : Screen
24 : Sensor
40 : Conventional counter
50 : Improved conventional counter
160 : Apparatus for recycling balls according to another embodiment
CROSS-REFERENCE TO RELATED APPLICATION
This application claims a priority under 35 U.S.C §119 (a) on Patent Application No. 10-2012-0104771, filled in Korean on Sep. 20, 2012, and Patent Application No. 10-2012-0104772, filled in Korean on Sep. 20, 2012, the entire contents of which are incorporated herein by reference.
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The present invention relates to an apparatus for circulating balls. An embodiment of the present invention includes: a circulation path for circulating balls and fluid, the circulation path comprising a cooling water tube of a heat exchange unit; a pump arranged in the circulation path for pumping the balls and fluid; and a counter for counting the time and the number of the balls in relation to the circulation of the balls.
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1. CROSS-REFERENCE TO RELATED APPLICATION
This application claims priority to U.S. Provisional Patent Application No. 61/919,730, filed, Dec. 21, 2013, and is a continuation-in-part of U.S. patent application Ser. No. 13/475,979, filed May 19, 2012.
BACKGROUND OF THE INVENTION
2. Field of the Invention
The invention relates to general purpose arithmetic logic units (ALUs), and in particular to an ALU utilizing a residue number system in performing arithmetic operations.
3. Related Art
The binary number system is the most widely used number system for implementing digital logic, arithmetic logic units (ALU) and central processing units (CPU). Binary based computers can be used to solve and process mathematical problems, where such calculations are performed in the binary number system. Moreover, an enhanced binary arithmetic unit, called a floating point unit, enhances the binary computers ability to solve mathematical problems of interest, and has become the standard for most arithmetic processing in science and industry.
However, certain problems exist which are not easily processed using binary computers and floating point units. One such class of problems involves manipulating and processing very large numbers. One example is plotting the Mandelbrot fractal at very high magnification. In order to plot the Mandelbrot fractal at high magnifications, a very long data word is required. Ideally, the Mandelbrot fractal plotting problem necessitates a computer with an extendable word size.
The main issue is that any real computer must be finite in size, and consequently the computer word size must be fixed at some limit. However, closer analysis reveals other contributing problems. One such problem is the propagation of ì carryî bits during certain operations, such as addition and multiplication. Carry propagation often limits the speed at which an ALU can operate, since the wider the data word, the greater the path for which carry bits are propagated. Computer engineers have helped to reduce the effect of carry by developing carry look-ahead circuitry, thereby minimizing, but not eliminating, the effects of carry.
However, even the solution of implementing look-ahead carry circuits introduces its own limitations. One limitation is that look-ahead carry circuits are generally dedicated to the ALU for which they are embedded, and are generally optimized for a given data width. This works fine as long as the CPU word size is adequate for the problems of interest. However, once a problem is presented which requires a larger data width, the CPU is no longer capable of using its native data and instruction formats for direct processing of the larger data width.
In this case, computer software is often used to perform calculations on larger data widths by breaking up the data into smaller data widths. The smaller data widths are then processed by the CPUis native instruction set. In the prior art, software libraries have been written specifically for this purpose. Such libraries are often referred to as arbitrary precisioni math libraries. Specific examples include the arbitrary precision library from the GNU organization, and the high precision arithmetic library by Ivano Primi.
However, software approaches to processing very large data widths have significant performance problems, especially as the processed data width increases. The problem is that software processing techniques tend to treat the smaller data widths as digits, and digit by digit processing leads to a polynomial increase in execution time as the number of digits increases. In one example, an arbitrary precision software routine may take four times as much time to execute when the data width is doubled. When using arbitrary precision software solutions, the amount of processing time often becomes impractical.
One possible solution is to build a computer which is not based on binary arithmetic, and which does not require carry propagation logic. One candidate number system is the residue number system (RNS). Residue number addition, subtraction and multiplication do not require carry, and therefore do not require carry logic. Therefore, it is possible that RNS addition, subtraction and multiplication be very fast, despite the word size of the ALU. These facts have provided some interest for RNS based digital systems in the prior art; unfortunately, prior art RNS based systems are only partially realized, and have failed to match the general applicability of binary based systems in essentially every instance. This fact is evident from the lack of practical RNS based systems in the current state of the art.
The reasons for the failure of RNS based systems to displace binary systems are many. Fundamental logic operations, such as comparison and sign extension, are more complex in RNS systems than traditional binary systems, and require more logic circuitry and execution time. For many experts, it is often assumed the difficulty of RNS comparison, RNS to binary conversion, and RNS sign and digit extension make RNS based processors and ALUs impractical for general purpose processing.
In addition to the problems noted above, the lack of a practical RNS integer divide further restricts the applicability of RNS based systems of the prior art. Also, the lack of general purpose fractional number processing has (severely) restricted the usefulness of RNS based digital systems of the prior art. In summary, prior art RNS systems cannot process numbers in a general purpose manner, and this has relegated such systems to little more than research subjects.
From the discussion that follows, it will become apparent that the present invention addresses the deficiencies associated with the prior art while providing numerous additional advantages and benefits not contemplated or possible with prior art constructions.
BRIEF DESCRIPTION OF THE DRAWINGS
The components in the figures are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention. In the figures, like reference numerals designate corresponding parts throughout the different views.
FIG. 1 is a block diagram illustrating the first stage of a two stage apparatus for fractional binary to fractional residue conversion.
FIG. 2 is a block diagram illustrating the second stage of a two stage apparatus for fractional binary to fractional residue conversion.
FIG. 3 is a block diagram illustrating the first state of a two stage apparatus for example demonstration of a fractional binary to fractional residue converter.
FIG. 4 is a block diagram illustrating the second state of a two stage apparatus for example demonstration of a fractional binary to fractional residue converter.
FIG. 5 is a waveform timing diagram of an example demonstration of a fractional binary to fractional residue converter.
FIG. 6A is a block diagram illustrating a fast residue multiply and normalization apparatus for use as a fractional residue multiplier apparatus.
FIG. 6B is a block diagram illustrating a fast residue multiply and normalization apparatus for use as a fractional residue multiplier apparatus.
FIG. 7 is a block diagram illustrating a modular arithmetic addition processing unit.
FIG. 8 is a block diagram illustrating a modular arithmetic subtract processing unit.
FIG. 9 is a block diagram illustrating a modular arithmetic add and accumulate unit.
FIG. 10 is a block diagram illustrating a modular arithmetic add unit with extended digit range.
FIG. 11 is a block diagram illustrating a modular arithmetic multiplier unit.
FIG. 12 is a block diagram illustrating a modular arithmetic inverse modulus multiplier unit.
FIG. 13 is a block diagram illustrating a residue to mixed radix converter unit.
FIG. 14 is a block diagram illustrating a mixed radix digit, power term multiplier unit with power term source.
FIG. 15 is an example fractional residue multiplication computation illustrating intermediate residue values and states.
FIG. 16 is a flow control diagram illustrating the control steps of a fractional residue multiplier apparatus.
FIG. 17 is a table pictorial illustrating the organization of a power term source.
FIG. 18 is an example fractional residue multiplication computation illustrating intermediate residue values and states.
FIG. 19 is an example fractional residue multiplication computation illustrating intermediate residue values and states.
FIG. 20 is a block diagram of a fractional residue value separator unit.
FIG. 21 is a block diagram of a fractional residue multiplier apparatus.
FIG. 22 is a block diagram of a fractional portion only multiplier unit.
FIG. 23 is a table pictorial illustrating the organization of a power term source.
FIG. 24 is an example fractional residue multiplication computation illustrating intermediate residue values and states.
SUMMARY OF THE INVENTION
Various converter and multiplier apparatus and methods utilizing residue numbers are disclosed herein. For instance, in one exemplary embodiment, a residue number normalization unit may comprise a plurality of digit processing units that perform one or more modular arithmetic operations on one or more operands to generate an output within a predefined modulus value, a common data bus that transmits data to and from each of the plurality of digit processing units, and a digit power multiplier that receives a mixed radix digit and an associated digit power value, and transmit a resulting weighted digit power product. The multiplier is coupled to the digit power accumulator, and the modular arithmetic operations do not result in a carry value.
The residue number normalization unit also includes a digit power accumulator coupled to a result selector that receives and accumulate weighted digit power products, and a controller that transmits one or more commands to instruct one or more of the plurality of digit processing units to: convert one or more residue numbers having at least a fractional representation to a plurality of digits in mixed radix format; receive one or more mixed radix digits, each digit associated with a mixed radix power, and multiplying the digit value by the associated mixed radix power, thereby forming a weighted digit power product; and sum a selected portion of the plurality of weighted digit power products The result selector, responsive to one or more controller commands, transmits a result from among one or more candidate normalization values.
In another exemplary embodiment, a residue converter configured to convert a fractional binary value to a fractional residue value is provided, with such residue converter comprising an input register that receives a plurality of binary input digits, the plurality of binary input digits configured as a parallel binary input receiving a binary fractional value, a modulus shift register that stores a plurality of modulus values and to output each of the plurality of modulus values in sequence, and a first plurality of digit processing units that performs one or more arithmetic operations on a plurality of binary input digits and on a sequence of modulus values, and to generate a plurality of digit values and modulus values.
Each digit processing unit comprises a modulus operand register that receives a modulus value from a prior processing stage, and configured to send a modulus value to a succeeding processing stage, an additive operand register that receives a digit value from a prior processing stage, a digit accumulator that stores a binary digit value, a multiplier that multiplies the contents of said digit accumulator with the contents of said modulus operand register generating an accumulator modulus product, and an adder that adds said accumulator modulus product with the contents of said additive operand register, and configured to send a least significant portion of the adder result to said digit accumulator, and a most significant portion of the result to a successive processing stage.
A second plurality of digit processing units that receive digit values and modulus values from said first plurality of digit processing units, and to perform one or more modular arithmetic operations on a plurality of residue digits, each digit processing unit are also included. Each of the second plurality of digit processing units comprise a residue digit register that stores a residue digit, a modular multiplier that receives a modulus value from an input modulus bus and a value from said residue digit register, and is sends a residue product result, and a modular adder that receives said residue product result, and configured to receive a digit value from an input digit value bus. After a plurality of processing cycles, a fractional residue number equivalent to a binary fractional input is stored in the plurality of said residue digit registers;
It is noted that at least one said prior processing stage is said modulus shift register, and at least one said digit processing unit configured to send a digit value and a digit weight to a second plurality of digit processing units. Also, the first plurality of digit processing units process numbers in binary format while the second plurality of digit processing units process digits in residue number format.
Various methods are disclosed herein as well. For example, a method for multiplying a first fractional residue operand to a second fractional residue operand is provided, with such method comprising separating a first fractional residue operand into a first fractional only portion and a first whole integer only portion, separating a second fractional residue operand into a second fractional only portion and a second whole integer only portion; multiplying the first fractional only portion with the second fractional only portion forming an intermediate fractional only product term, multiplying the first fractional only portion with the second whole integer only portion to form a first intermediate fraction and whole product term, and multiplying the second fractional only portion with the first whole integer only portion to form a second intermediate fraction and whole product term.
The method also includes multiplying the first whole integer only portion with the second whole integer only portion forming a whole integer only product, scaling the whole integer only product by a fractional range value forming a scaled whole integer only product, truncating a first fractional only portion forming a truncated first fractional only portion, truncating a second fractional only portion forming a truncated second fractional only portion, multiplying the truncated first fractional only portion with the truncated second fractional only portion forming a truncated partial product, subtracting the truncated partial product from aforementioned intermediate fractional only product term forming an intermediate fractional product term evenly divisible by a fractional range, and multiplying the intermediate fractional product term that is evenly divisible by a fractional range with a multiplicative inverse of a fractional range forming a recovered fractional only portion. A final result is generated by summing a recovered fractional only portion, a first intermediate fraction and whole product term, a second intermediate fraction and whole product term, and a scaled whole integer only product.
Other systems, methods, features and advantages of the invention will be or will become apparent to one with skill in the art upon examination of the following figures and detailed description. It is intended that all such additional systems, methods, features and advantages be included within this description, be within the scope of the invention, and be protected by the accompanying claims.
DETAILED DESCRIPTION
1. Improved Fractional Binary to Fractional Residue Converter Apparatus
In order to take advantage of high speed operation of the RNS ALU, high speed conversion of integer and fractional data, from binary to residue format, is required. FIG. 1 and FIG. 2 disclose a streamlined version of the conversion apparatus described in U.S. Patent Publication No. 2013/0311532, which is incorporated herein by reference. The streamlined apparatus requires less clock cycles for the conversion process, therefore, it is generally faster.
FIG. 1 and FIG. 2 illustrate a J+K digit converter apparatus of the present invention by means of example. FIG. 1 discloses a first plurality of J binary digit stages, and FIG. 2 discloses a second plurality of K number of RNS digit stages. The converter is an enhanced version of the forward fractional converter of U.S. patent application Ser. No. 13/475,979.
The apparatus accepts a fractional only binary value into the B_IN port shown at top of FIG. 1 . The B_IN port accepts binary data using a series of binary digit latches, B 0 _ IN 100 through B J−1 _ IN 103 . The digit latches may have the same maximum bit width Q as the residue digits of FIG. 2 in one embodiment. These latches are for input holding only, and may be replaced by a bus in some embodiments.
In the first clock cycle, the binary value (B 0 ) through (B J−1 ) input at B_IN is latched into conversion data registers A 0 150 through A J−1 153 . Also, modulus registers M 0 120 through M 3 123 are initialized with the value of one using hardware not shown for sake of clarity. This initialization ensures the values of digit registers A 0 through A J−1 are not destroyed, but are preserved in the next following clock cycle.
As taught in U.S. patent Publication No. 2013/0311532, a plurality of modulus values is associated to an RNS fractional range. As shown in FIG. 1 and by means of example, F number of modulus values are associated with the fractional range, such as modulus M F−1 111 . All F number of modulus values are stored, or pre-stored, into a memory or shift register, shown by modulus shift register 110 . Upon each clock of the conversion, the modulus values stored in modulus shift register 110 are sequentially shifted into modulus data register M 0 , where M 0 feeds M 1 , and so on and so forth through M J−1 as shown. At each clock cycle, each modulus value serves as an operand to a specific digit multiplier of a digit processing block, such as multiplier 130 thru 133 , thereby multiplying the current state of the digit A 0 150 thru A J−1 153 by a different modulus value.
During each clock cycle, a carry value may be generated by each digit multiplier, illustrated by data path 170 for example. In one preferred embodiment, the carry value data width equals the data width of the binary input digit, so designated as Q in FIG. 1 . Each carry value propagates towards the left and is latched by the next digit processing unit in FIG. 1 . In FIG. 1 , the high order bits of the last digit multiplier, shown by example as multiplier 133 , is output by digit output bus 161 to the second plurality of RNS digit processing stages as shown in FIG. 2 . Likewise, the modulus value shifted into the last modulus register stage 123 is output by bus 160 to the second plurality of RNS digit processing stages of the converter shown in FIG. 2 .
During operation, at some number of clock cycles, modulus values stored in modulus shift register 110 begin appearing at modulus output bus 160 ; likewise, carry values begin appearing at digit out bus 161 . In FIG. 2 , a second plurality of digits stages is shown by means of example. The modulus out bus 160 of FIG. 1 connects and drives modulus crossbar 160 of FIG. 2 . Likewise, the digit output bus 161 of FIG. 1 connects to and drives digit crossbar bus 161 of FIG. 2 .
In FIG. 2 , at each clock cycle, residue digit processing units 220 , 221 , 222 , 223 multiply, in a modular fashion, the value of the modulus output value 160 by the current value of digit registers 260 , 261 , 262 , 263 respectively. Each multiplier result is summed, in a modular fashion, to the value on the digit out bus 161 and stored back into the digit register 260 , 261 , 262 , 263 respectively. The adders 250 , 251 , 252 , 253 and multipliers 240 , 241 , 242 , 243 perform modular arithmetic, and support a multiply, add and accumulate operation for a specific and unique pair-wise prime digit modulus respectively. In one preferred embodiment, digit function blocks, such as digit function blocks 220 , 221 , 222 , 223 , act in unison and perform a similar operation, but with a different modulus value. When the last modulus and carry value exit the apparatus of FIG. 1 via modulus out data path 160 and digit out data path 161 , they are processed by the plurality of RNS digit function blocks of FIG. 2 , and the final result is stored in digit accumulator registers 260 , 261 , 262 , 263 . A final converted result, in residue fractional format, may be transferred out of the converter using digit buses 270 , 271 , 272 , 273 .
The residue multiply and add operation performs the same arithmetic calculations as the later stages of the fractional converter of FIG. 20D of U.S. patent application Ser. No. 13/475,979. In that disclosure and referring to FIG. 20D , the high order (leftmost) digit function blocks are replaced by a series of residue stages as shown in the present disclosure of FIG. 2 . It is noted the first stages of both converters remain much the same. According to the new enhancements, once stage 1 conversion has completed processing, the second stage as shown in FIG. 2 will typically terminate one or two clocks later. On completion, the second plurality if RNS digit processing units contains the scaled fractional value in residue format. This is in contrast to the invention of FIG. 20D of U.S. patent application Ser. No. 13/475,979 where the second plurality of digit processing units is in binary format, and therefore requires additional clock cycles to further complete conversion into a residue fractional format.
FIG. 1 also discloses apparatus for detecting a round-up of the converted result. Rounding is an important feature, and is typically a mandatory feature in order to provide a converted result with the most accuracy. In FIG. 1 , after the basic conversion described above is complete, the values of binary register digits A 0 150 through A J−1 153 are valid. The value contained in the binary registers is a remainder of the conversion, and may be compared with a round-up threshold value 155 using comparator 156 . In one embodiment, if the value equals or exceeds the threshold, the converted value contained in registers D 0 273 thru D K−1 is rounded up by incrementing the converted value by one unit. For example, if rounding is performed, each digit register 260 , 261 , 262 , 263 of FIG. 2 is incremented by one in a modular fashion. In some embodiments, only the most significant binary bit of the most significant binary digit, i.e., A3 153 , is used to determine if a round-up is required. If a round-up is required, such indication may be transmitted by carry out bus 162 to a controller, not shown, responsible for performing the increment operation. It should be clear to those skilled in the art of digital design that alternate types of rounding and/or alternate threshold values may be used.
When considering the conversion of a fractional binary value which contains both a fractional part and a whole (integer) part, the integer part may be separated from its fractional part before conversion begins in one embodiment. This is beneficial, since fractional conversion differs from integer conversion, and performing both conversion processes in separate and in parallel saves time. In one embodiment of the present invention, integer and fractional conversion are performed in parallel. After conversion, the integer and fractional values are added together when in residue format. Conversion of integer and fractional values in parallel generally improves throughput of real-world conversions. This teaching is disclosed in U.S. Patent Publication No. 2013/0311532 and is not dealt with in any more detail herein.
In FIG. 3 , FIG. 4 , and FIG. 5 , an example fractional conversion is illustrated to clarify the apparatus of FIG. 1 and FIG. 2 . In this example, FIG. 3 is derived from FIG. 1 and shows four distinct binary digit processing stages or units, and FIG. 4 is derived from FIG. 2 and shows four distinct RNS digit processing stages or units. Reference designators from FIG. 1 and FIG. 2 have been preserved in FIG. 3 and FIG. 4 for clarity. In addition, a timing diagram illustrating the various data flows of the example conversion apparatus of FIG. 3 and FIG. 4 is disclosed in FIG. 5 . At the bottom of FIG. 5 , the reader will note the actual numerical values used in the conversion apparatus example. These example values coincide with the example values provided in U.S. Patent Publication No. 2013/0311532 for clarity of disclosure and comparison of the methods.
It should be noted that in any specific embodiment of the present invention, the number of digit processing stages of the first plurality of binary digit processing units need not equal the number of digit processing stages of the second plurality of RNS digit processing units. Moreover, the number of associated fractional modulus contained in modulus shift register 110 of FIG. 1 need not match either the number of binary digit processing units or the number of RNS digit processing units. However, in the following example disclosure, all of these numbers equal four by means of example only.
In the waveform diagram of FIG. 5 , the flow of data is illustrated through the apparatus of FIG. 3 . When viewing the waveform diagram, each major storage register is denoted under the first column, i.e., the column labeled “register”. For example, the modulus registers M 0 120 thru M 3 123 are listed as the first four registers in the waveform diagram of FIG. 5 in the rows 511 , 512 , 513 , 514 . Also shown in the waveform diagram of FIG. 5 is ten columns denoting each clock cycle of the conversion process, labeled cycle 0 thru cycle 8 . When considering a particular storage element, the value stored in that element may change in each successive cycle. Therefore, traversing the waveform diagram from left to right indicates the register values for each storage element on a cycle by cycle basis.
When viewing the contents of a plurality of registers at any given instant, for example, digit registers A 0 150 thru A 3 153 of FIG. 3 , one may inspect the values in one column of the waveform diagram of row 515 , 517 , 519 , 521 respectively. For example, at cycle 0 , the register values contained in A 0 , A 1 , A 2 and A 3 are all seen to be hex digit value five (0×5) in FIG. 5 . This corresponds to the loading of the fractional binary value 0×5555 at the start of conversion per the example values provided. Moreover, the modulus registers M 0 , M 1 , M 2 and M 3 are seen to be initialized to the value of one at cycle 0 which corresponds to the initialization of all modulus registers with the value of one prior to conversion processing.
In FIG. 5 , in row 515 , and moving to the cycle 1 column, the result of the first clock of the conversion process is shown, which illustrates that digit register A 0 has transitioned from the hex value of 0×5 to the hex value 0×A. Also shown in the clock 1 column, rows 517 , 519 , 521 show the digit registers A 1 , A 2 and A 3 remain unchanged. In addition to the transitions of modulus registers and digit registers, rows 516 , 518 , 520 illustrate the storage or transmission of carry values from previous digit processing stages of FIG. 3 for each clock cycle. In particular, the value output by digit out bus 161 of FIG. 3 is generated from the last carry output labeled “Digit out” of FIG. 5 , row 521 , which is connected to the digit crossbar 161 of FIG. 4 . Likewise, the value of modulus register M 3 123 of FIG. 3 is shown in FIG. 5 , row 514 , and this value therefore drives the Modulus out bus 160 , which is connected to the Modulus crossbar 160 of FIG. 4 .
Also shown in FIG. 5 , rows 522 , 523 , 524 , 525 are the states of the four RNS digit registers D 0 , D 1 , D 2 and D 3 respectively. The RNS registers are initialized to zero as shown in the cycle 0 column of the waveform diagram of FIG. 5 . At clock cycle 4 , the digit out bus 161 will output a value of zero, and the modulus out bus 160 will output the value of two. Therefore, in the next clock cycle, all four RNS digit processing units of FIG. 4 will process the two values on each of the crossbar buses. Because all RNS digit registers are zero, the multiplication result will be zero in each digit processing unit, and the following addition of zero will result in each RNS digit register receiving the value of zero. This result is shown in the next cycle, the cycle 5 column of FIG. 5 , rows 522 , 523 , 524 , 525 .
During cycle 5 of the waveform diagram, the next digit out bus value will be one and the next modulus out bus value will be three. Therefore, in the next cycle, cycle 6 , each RNS digit register will multiply its zero value by three (3), and add a value of one. This results in a value of one stored in each RNS digit processing unit D 0 thru D 3 of FIG. 4 . In cycle 6 , the digit out bus will receive the value of four, and the modulus out bus will receive the value of five (5). Therefore in cycle 7 column, the value of one stored in each RNS digit processing unit will be multiplied by five and this result will be added to four and stored back into each RNS digit register D 0 thru D 3 . Taken together, the RNS value contained in registers D 0 thru D 3 is the value nine (9) which is represented by the RNS value (1,0,4,2) using the example modulus of (2,3,5,7), since each RNS digit processing unit is modulo its pair-wise prime modulus.
In cycle 7 , the next digit out bus value is shown to be six (6), and the next modulus out bus value is shown to be seven (7). Again, multiplying nine by seven results in a value of 63, and adding the value of 6 results in an RNS register value of 69. This result is shown in cycle 8 of FIG. 5 and is represented as the RNS value (1,0,4,6) shown enclosed in the dotted ellipse 500 . In cycle 8 , the modulus register value is one, and therefore, the conversion process is over with the exception of a possible round-up correction.
In cycle 8 , the remainder value of the conversion is contained in binary digit registers A 0 thru A 3 , and this value is 0×FFBA. Since this value is greater than half the range of a normalized unit, i.e. 0×8000, then the final RNS value stored in registers D 0 thru D 3 is incremented by one using a modulo add. The modulo increment may be performed by sending a value of one to the Modulus crossbar (which it is be default), and by sending the TRUE output of the comparator 157 of FIG. 3 , interpreted as the value one, to the digit crossbar via selector unit 280 of FIG. 4 . In other words, selector 280 of FIG. 4 is enabled such that it selects the output of comparator 156 of FIG. 3 , and gates a value of one to the digit crossbar if the comparator output indicates a round up should be performed. If so, the RNS value contained in digit registers D 0 thru D 3 is incremented. This is shown in cycle 9 as the RNS value (0,1,0,0) and this value is shown enclosed in the dotted lines 510 of FIG. 5 .
As shown in the example values section of FIG. 5 , the resulting RNS fractional value is exactly the fractional value of one third, since 70/210 is exactly interpreted as the correctly converted value of the approximated one third value represented in a binary fractional format ( 0×5555/0×10000). This ends the example section of the improved converter of the present invention.
2. Fractional RNS Multiplier Apparatus
There is a need for faster fractional residue multipliers. As disclosed in U.S. Patent Publication No. 2013/0311532, several embodiments for fractional RNS multipliers was disclosed. In one embodiment, the fractional multiplier provided for a single clock per RNS digit plus some additional clocks to convert the mixed radix intermediate result back to residue format for continued processing.
In this application, several new methods and apparatus providing fractional value RNS multiplication are disclosed. Specifically, a new method and apparatus is provided which is built upon the apparatus disclosed in U.S. Patent Publication No. 2013/0311532 but further reduces, or eliminates, the clocks required for final conversion of mixed radix back to residue format. This reduces the total number of steps or clocks, and provides for faster operation. Second, a still faster method and apparatus for fractional RNS multiplication is provided that further reduces the required clocks or steps by performing steps in parallel. This second method provides a tradeoff by requiring increased hardware in return of reduced processing latency. Reduced processing latency is required in many applications, in which the result of the multiplication is needed immediately for further processing.
Both new methods and associated apparatus increase the speed at which a single fractional multiplication can be performed in residue format. Both methods therefore reduce the latency of a single multiplication in residue format. We will introduce the first improved method next.
In U.S. Patent Publication No. 2013/0311532, FIGS. 15A, 15B and 15C provide flowcharts for several novel RNS fractional value multipliers. In that application, a suitable fractional RNS format is devised, and several unique apparatus are disclosed which perform a multiply of two fractional RNS values. In FIG. 15C of that application, an advanced multiplier is disclosed which performs multiplication of signed fractional values. Likewise, the present invention discloses a method which performs the operations disclosed in the flowchart 15C, but in a more efficient manner in terms of clock cycles. With respect to the new methods disclosed herein, and referring to FIG. 15C of U.S. Patent Publication No. 2013/0311532, the steps of conversion of mixed radix back to residue format 1530 a and 1530 b is performed in parallel with the process of converting the original product from residue to mixed radix 1525 a and 1525 b.
This is possible, since each mixed radix digit represents a weighted value. The value represented by each mixed radix digit may be converted to a residue value. One may therefore convert each mixed radix digit to a residue value, and add this value to a residue summation of all other converted digits. The final residue summation will be the truncated mixed radix value in residue format, provided the mixed radix digits associated with the fractional digits are discarded, i.e., not added to the residue summation. Therefore, using a new and unique apparatus of the present invention, during the conversion cycle of a mixed radix digit, its value may be converted and summed in residue format in the same or next clock cycle.
The unique new RNS fractional multiplier of the present invention can process the operation in P clocks for a P digit fractional format. This P digit format includes all extended digits required to contain the extended, or non-normalized, fractional value.
One unique and preferred embodiment for a scalar residue multiplier is shown in FIG. 6A . It is noted that a scalar multiplier is specifically not a pipelined multiplier unit. A fully pipelined variation of the new multiplier is also a claimed invention, but its design details are not disclosed in this application; however, such a variation should be evident to those skilled in the art of digital design. The new RNS multiplication starts with a non-normalized product, denoted as block 600 in FIG. 6A . This is similar to FIG. 15 c of U.S. Patent Publication No. 2013/0311532, whereas the multiplication starts with an RNS integer multiply of two fractional value operands (i.e., treating both fractional value operands as integers and multiplying both operands using an RNS integer multiply). The resulting product is loaded into register 600 , in RNS format, upon start of the fractional multiply. In this disclosure, such a product value is commonly called an intermediate product (IP), and may also be referred to or described as a non-normalized product. Additionally, other non-normalized intermediate products, such as a fractional product sum, may be a suitable starting value at register 600 .
Valid sign flags or sign extended operands are not needed for either or both operands at start; instead, the new multiplier will produce a result that is signed and flagged as sign valid. In other words, the new multiplier produces a fully sign extended, normalized result regardless of whether the operands themselves have been sign extended. This is accomplished using two values computed in parallel, i.e., the original intermediate product value and the complement of the original intermediate product value. This complement operation is performed on the non-normalized product 600 by complement unit 602 . The complement is therefore loaded for processing into the residue to mixed radix converter 620 . The original (non-normalized) value 600 is loaded directly into its own residue to mixed radix converter 610 .
One may view the residue multiplier of FIG. 6A as computing two answers. Of the two possible results, the result having the smallest magnitude is always the correctly processed value. If the smallest result is derived from the complemented intermediate product 602 , the final result is known to be negative, and therefore the correctly processed result must be complemented again as a final step using complement unit 650 .
The residue to mixed radix conversion was described in detail in U.S. Patent Publication No. 2013/0311532, to which novel advancements to its digit unit design are disclosed herein. In particular, the present disclosure highlights a solution for digit ALU logic which does not require excessively large look up tables (LUT). In this embodiment, LUT size does not dramatically increase as digit width is increased. A residue to mixed radix converter which may utilize the described residue digit processing units will follow next, however, it should be clear that many other solutions to digit logic exist including LUT based solutions. These other solutions do not minimize the novel method of the fractional multipliers of the new inventions described herein.
A. Residue Digit Logic Enhancements
To better explain the residue based fractional multipliers of the present invention, we will first review the required residue digit logic, otherwise known herein as the residue digit processing unit. Residue digit logic is the logic used to employ the basic modulo digit operations required within a residue ALU, such as the residue ALU disclosed in U.S. Patent Publication No. 2013/0311532. The residue digit logic apparatus and their associated operations are also used in the design of residue ALU sub-units, such as multipliers, adders, and converters.
In a residue ALU, most digit operations are modular arithmetic. In at least one embodiment, each digit has its own modulus p pre-assigned. When adding two arbitrary numbers, digits of the same modulus are added and a MOD function modulo p is applied to the result. (The mod function is commonly denoted as % in C programming language.) If only legal values of a residue digit are added between two arbitrary values, then a basic ì single rangeî residue digit adder will suffice. In this context, a legal digit value includes zero and any positive value up to, but not including, the pre-assigned modulus p. The single range modulo adder is composed of a conventional binary adder, a comparator and a subtract unit to implement the modular add function. This type of circuit is conventional to those skilled in the art, and is shown in FIG. 7 .
In FIG. 7 , residue digit values, A and B, are summed using a binary add unit 700 . The result of the binary add is then transferred to one input of a binary subtract unit 710 , and also the result is transferred to one input of a binary comparator 730 . The circuit is so configured that if the result of binary addition 700 is less than the digit modulus p, the modulus p designated as M in FIG. 7 , the result is sent directly as a result through bus selector 720 since the output of comparator 730 is TRUE, or 1. If the output of comparator 730 is FALSE, or 0, then the result of the add unit 700 is greater than or equal to the modulus M, so the bus selector selects the output of the subtract unit 710 , which decreases the binary sum by the amount of the modulus M. The correct modular sum result appears on output R of bus selector 720 in either case. The digit function is general, since it may take on any value of modulus, M=p.
The operation of single range modulo subtract unit is very similar to that of modulo addition, and is also conventionally known to those skilled in the art. In the most basic case, simplification results from the fact that a single range subtraction is bounded to less than twice the digit range. In this case, a single subtract unit, a single add unit and a single comparator can be used. In FIG. 8 , a novel yet minor improvement uses borrow signal 830 from a binary subtract unit 800 to replace the comparator of FIG. 7 . If the result of the subtract unit 800 is positive, borrow signal 830 is false, and bus selector 820 passes the subtract unit 800 result directly to result R. Otherwise, if the borrow signal is asserted, the binary subtract unit 800 result is negative, and so the value of the modulus M is summed to the result using add unit 810 . Bus selector 820 passes the output of add unit 810 since the borrow signal 830 is true. Again, in either case, the correct modular digit subtract result appears as a result.
The same logic reduction used to implement the modular digit subtract unit of FIG. 8 can be adapted to a single range modulo digit add unit of FIG. 7 by introducing a borrow signal that steers the correct value to the output. This is shown in FIG. 9 where a single range modular digit add unit 900 is depicted. In particular, the modular digit add unit 900 of FIG. 9 also supports a registered result 930 whose output 940 is fed back to one of the operand inputs of the modular add unit 900 . This modification to the modular add unit 900 is termed a modular digit add and accumulate unit.
Residue digit functions such as add and subtract are more complex if the range of the digit operands exceed the legal digit range. This can occur if the digit processing unit must accept an operand from another digit modulus, for example. In this case, the relative value of digit modulus with respect to each other is an important design parameter for the residue ALU. For example, if no modulus is more than twice as large as any other modulus, then digit subtract circuits may be designed to handle this extended digit range of input operands. On the other hand, if the plurality of modulus p of an ALU varies widely, say by a factor of 4 or 5 times, then more complex circuits are needed. FIG. 10 shows a digit adder circuit which supports a larger range. The operation of the extended range add or subtract unit is not discussed in detail and should be obvious to those skilled in the art.
Residue digit multiplication is another important requirement of the residue ALU. Residue digit multiplication is again modular, and since the product of a normal binary multiplier produces a range far in excess of the modulus M=p, a means for applying a MOD p function (% p) across this range is required. In many cases, a LUT memory is used. If a LUT memory is used in a brute force fashion, very large memories are required if the digit modulus is large, since up to M*M table entries may be needed. Therefore, there is a need to reduce the size of LUT memory for implementing modular digit functions such as digit multiplication.
FIG. 11 shows a novel implementation of a residue digit multiplier which significantly reduces the amount of LUT memory needed. The multiplier unit uses a conventional binary multiplier 1100 to multiply two n-bit operands A and B. The n-bit operand width should be wide enough to accept the range of the modulus values required, which may include digit values from other digit modulus outside the legal range of the digit modulus M=p. The product output of multiplier 1100 is 2*n bits wide. The low order n bits of the product output 1102 are routed to LUT 1112 , and the high order n bits of the product result 1104 are routed to LUT 1110 .
In the embodiment of FIG. 11 , low order LUT 1112 is programmed using the following formula: data[LUT_ADR]=LUT_ADR % M. High order LUT 1110 is programmed using: data[LUT_ADR]=(LUT_ADR*2 n ) % M.
The effect of the LUT 1112 and LUT 1110 is to provide two unsigned integers whose sum MOD M is the correct modular multiplication result R. Each LUT output is bounded by modulus M, so the sum of each output may not exceed the modulus M by two times; therefore, the basic modular digit adder of FIG. 7 may be used to provide the correct result. Similar to FIG. 7 is the solution in FIG. 11 , which shows a binary adder 1120 , comparator 1130 , subtract unit 1140 and bus selector 1150 configured to provide the modular addition of the results of each LUT 1110 and 1112 . The result R appears at the output of bus selector 1150 .
Another important modular digit operation is inverse multiplication, also referred to as MODDIV in U.S. Patent Publication No. 2013/0311532. As disclosed in that application, this operation may be implemented in a brute force manner using a LUT memory. However, this application also discloses a unique and novel method for implementing a smaller LUT which encodes a multiplicative inverse of a given modulus p 0 with respect to another digit modulus p 1 . A LUT table therefore includes N−1 number of multiplicative inverses for the given p, which provides a means to process a multiplicative inverse digit operation with respect to any other given digit modulus for an ALU having N distinct pair-wise prime digit modulus. For inverse modular digit multiplication of the present invention, the primary requirement is that for every digit modulus, a multiplicative inverse exists for each of the other supported digit modulus. A digit modulus does not require an inverse for itself, since this digit is undefined after digit division by its own modulus.
In FIG. 12 , the modular digit multiplier of FIG. 11 is shown with the addition of LUT 1200 . The LUT 1200 contains the multiplicative inverse of the given digit modulus p with respect each other digit modulus of the ALU or ALU unit. The input 1205 to the look-up table (LUT) 1200 is labeled ì Div_modî, which is an index to the specific multiplicative inverse (of p) associated with, and with respect to, the indexed modulus. The output of LUT 1200 , i.e., the multiplicative inverse ofp with respect to the selected modulus, “Div_mod”, is then multiplied by a digit value input via bus 1210 using multiplier 1100 . The remainder the modular multiply apparatus remains identical to the modular digit multiplier of FIG. 11 .
For example, a residue ALU having 32 pair-wise prime digit modulus may support a 32 entry LUT 1200 to store 31 multiplicative inverses, each inverse associated with each of the other 31 modulus. Therefore, inverse modular multiplication can be used for dividing a residue value by any of the ALU digit modulus, by first ensuring the overall residue value is evenly divisible by the selected modulus, then by multiplying each digit of the ALU by its multiplicative inverse of the selected modulus specified by the “Div_mod” index input 1205 . In one preferred embodiment, each LUT 1205 for each inverse digit multiplier will be organized such that the Div_mod input 1205 is common to all inverse digit multiplier processing units.
In FIG. 6A , residue to mixed radix conversion unit 610 uses successive digit modulus divide operations to reduce the residue value into a series of mixed radix digits. This conversion process is well known, and is described in Tanaka as well as U.S. Patent Publication No. 2013/0311532. Before dividing a residue value by a particular modulus, the digit value at the particular modulus is subtracted from the entire residue value (the entire residue value is all residue digits interpreted as a single residue value). The subtracted digit is also a mixed radix digit that is output using data path 612 and data path 622 in FIG. 6A . Once a residue value is divided by a modulus value, the particular modulus is defined as skipped, or ignored. (In fact, the specific digit modulus is undefined until a base extension is performed.) In conversion of non-zero residue value to mixed radix, one or more digit modulus divides is performed on the residue value until it is reduced to zero. Before dividing a residue value by a specific digit modulus, the digit at that specific modulus becomes a mixed radix digit. All mixed radix digits generated complete an equivalent mixed radix number. The mixed radix number format is unique to a given sequence of digit modulus divides. Digit divides are performed using a subtract, then a multiply of the residue value by the inverse of the modulus divisor.
The residue to mixed radix conversion units 610 , 620 of FIG. 6A may support P number of digits, by means of example and as shown in further detail using FIG. 13 . The residue to mixed radix converter apparatus of FIG. 13 is similar to that disclosed in U.S. Patent Publication No. 2013/0311532. Control logic and circuitry is not shown for simplicity. A plurality of residue digit latches 1300 store an initial starting residue value having P number of residue digits. This starting value is loaded into the converter through a plurality of bus selectors, such as bus selectors 1355 , 1356 & 1357 as shown in FIG. 13 . The bus selectors send the initial residue value through P number of digit subtract units, such as digit subtract unit 1330 , 1331 , 1332 & 1333 . These digit subtract units may have circuitry similar to FIG. 8 in some embodiments, where each subtract unit contains a unique modulus value M. In some embodiments, an initial subtract operation by the value of the first digit processed is performed during the load operation. For example, in the apparatus of FIG. 13 , the first digit sends its value onto the digit subtract crossbar 1370 through tri-state buffer 1320 upon loading the initial start value. Each digit subtraction unit therefore applies the same digit value as a subtrahend operand via common crossbar 1070 .
The result of subtracting the digit value from the load value is then sent to the inverse multiplier unit for each digit processing unit 1310 . The inverse multiplier unit, taken as a whole, is shown as a plurality of digit function blocks, such as function blocks 1340 , 1341 , 1342 , & 1343 depicted in FIG. 13 . A typical inverse multiplier function block 1341 has a circuit similar to that of FIG. 12 in some embodiments. The inverse multiplier also supports a zero/skip output, which goes true if the digit is zero, or if the digit is marked skipped. The plurality of zero/skip outputs may be logically combined using AND gate 1381 in a basic embodiment. The output of AND gate 1380 provides a ì doneî output 1381 which is routed back to the controller not shown. In many embodiments, the first inverse multiply function block 1340 is not included, since the first digit need not be divided by itself, and is undefined after subtraction at initial load.
In the initial load cycle, the inverse multiplier of each digit processing unit, such as digit processing unit 1310 , multiplies the input digit by 1, thereby loading the initial residue value subtracted by the first digit into the converter inverse multiplier 1315 which typically supports a registered store for each product result. After the initial load cycle, on each successive clock, the counter 1375 indexes each digit LUT 1200 of FIG. 12 , each digit LUT 1200 producing a multiplicative inverse for the selected modulus. On each clock, the inverse multiplier 1315 divides the residue value by the selected modulus. The resulting product value is generally stored and made available to the subtract units for the next conversion cycle using a digit feedback path, such as feedback path 1351 and selector 1355 . After a value has been divided by a selected modulus, the associated digit of the specified divisor modulus is no longer valid, and is marked as skipped. A control unit, not shown, selects each digit and associated modulus in succession for subtraction and then subsequent division, in coordination with the modulus counter 1375 which indexes the divisor modulus. When the remaining residue value, which exists in the non-skipped digits, goes to zero, the conversion terminates. The conversion may also terminate when all digits are processed, i.e., skipped.
The residue digit subtracted may be output via digit crossbar 1370 in some embodiments. Therefore, digit crossbar 1370 outputs a mixed radix digit on each cycle of conversion. This crossbar output is shown on converter unit 610 and 620 as output bus 612 and 622 respectively in FIG. 6A . The zero flag is also shown coming from each converter unit 610 and 620 of FIG. 3 . The zero flag is made available to control logic to determine end of conversion. If a value during mixed radix conversion terminates before its complement, that values data path is used as the final output of bus selector 655 of FIG. 6A . Otherwise, a comparator state embedded in control unit 615 , representing the comparison of the initial non-normalized value 600 and its complement 602 , is used to determine which value is less in absolute magnitude. FIG. 6A illustrates a control block 615 providing a detection of both sign and round-up of the final result through the use of a successive digit comparison mechanism not shown. All digit comparison is performed least significant digit first due to the nature of mixed radix conversion.
The residue multiplier of FIG. 6A illustrates the function of the mixed radix conversion unit 610 . The output of residue to mixed radix conversion unit 610 is connected to a special power term multiplier unit 630 . The power term multiplier 630 takes a mixed radix digit output from the converter 610 , and multiplies the digit by its associated power, and then sums the resulting product to a running product summation contained in multiplier unit 630 . These calculations are performed in residue format. The source of the ì baseî power terms is provided by a power terms source units 605 , 625 . The power term units 605 , 625 may be the same in some embodiments. In one embodiment, the power term source 605 may consist of values pre-stored in a LUT or FIFO, or the power terms source 605 may be generated in real time by a residue arithmetic circuit, or other source which can provide the associated mixed radix digit power value in residue format.
The P digit power term multiplier 630 of FIG. 6A is shown in more detail in FIG. 14 . FIG. 14 also includes a power terms source 605 , which sources a power term value to the power term multiplier 630 of FIG. 6A on each multiply cycle. In FIG. 14 , a power term constant, such as power term constant 1440 , is stored in a plurality of residue digit storage registers, such as storage registers 1406 , 1407 , 1408 , 1409 , is routed to one input of a residue multiplier consisting of a plurality of modular digit multipliers, such as digit multipliers 1410 , 1411 , 1412 , 1413 . The other input to the multiplier is sourced from the mixed radix digit value input via input 1140 which feeds the mixed radix digit crossbar 1145 . This input is the connected to the mixed radix digit output 1370 of FIG. 13 . Therefore, on each clock cycle, an associated power term constant is multiplied by its respective mixed radix digit, thereby creating a weighted value output from the digit multipliers.
The power term constants 605 may be pre-stored using a LUT memory, or a FIFO shift memory, for example; alternatively, an arithmetic circuit may sequentially generate the required power term constants using a smaller table of stored modulus values. Generating modulus values using an arithmetic circuit has the added flexibility of producing power term constants with arbitrarily skipped modulus. This approach allows the multiply unit of FIG. 6A to normalize products with skipped digits, or to multiply operands with arbitrary or dynamically selected digit modulus.
The product of the mixed radix digit and its respective power term constant is then summed by a residue adder and accumulator register 1430 , shown as a plurality of digit add and accumulate units 1420 , 1421 , 1422 , 1423 in FIG. 14 . The digit add unit 1430 includes an accumulator function which state may be cleared prior to mixed radix conversion; FIG. 9 shows a more detailed diagram of a modular digit add and accumulator unit, such as add and accumulate unit 1420 of FIG. 14 . At startup, the digit adder 1420 may clear its accumulator register 930 as shown in FIG. 9 , and will therefore sum the first weighted value generated by the digit multiply units with zero. This effectively loads the first weighted digit product term into the accumulator for the next add cycle. In the next and following cycles, each weighted product term generated will be summed to the running total contained in the accumulator 1430 . This process continues for all digits in parallel until the conversion is complete.
Any suitable modular add and accumulate circuitry may be used, including LUTs. The modular add circuitry of FIG. 9 uses conventional binary adder 905 and binary subtract 910 and a bus selector 920 which steers the correct value based on the state of the borrow out signal 912 of the subtract unit 910 as explained previously.
After the mixed radix conversion is complete, and the last mixed radix digit is multiplied by its power term (weight) and summed within the residue add and accumulate unit 1430 , a resulting sum of products value is contained in the digit accumulator registers 1420 , 1421 , 1422 , 1423 . For the proper operation of the fractional multiplier of FIG. 6A , the sum of products representing the converted final result does not include any direct contribution from mixed radix digits associated with the fractional range. for example, fractional digits are the first F number of digits converted to mixed radix in one embodiment. These digits are not directly processed by the digit multiplier 630 , and thus, their weighted value has no direct contribution to the summation (re-converted result). However, it should be noted that the fractional digits are included in the mixed radix conversion process. In fact, it is important that during conversion of the intermediate product 600 and the complement of the intermediate product 602 , that the digit modulus associated with the fractional residue digits are converted first. This provides the needed division by the fractional rage, which is associated to the product of all fractional digit modulus.
In FIG. 6A , a suitable controller, not shown, contains the code and control flow to ensure that the first F digits converted by the mixed radix converter 610 are not processed by the digit multiplier 630 . Therefore, in some embodiments, power term constants (weights) for each of the digits associated to the fractional range, such as constant 1440 of FIG. 14 , are not stored in the power terms source unit 605 . Further concepts relating to the matter of skipping, and/or truncating mixed radix digits associated with the fractional range are disclosed in more detail in U.S. Patent Publication No. 2013/0311532.
The power term multiplier 630 outputs the summation result to the round-up unit 635 in FIG. 6A . The round-up unit 635 may exist as a separate unit as shown, or may be combined into the power term multiplier unit 630 . (For example, during the initial clearing cycle, the accumulator may be set to one if rounding is required.) For this example, a separate round-up unit is shown separately in FIG. 6A . The round up unit 635 consists of a plurality of modular digit adders, with one adder input tied to a selector which may select either one or zero. The other adder input is the summation value input from the power term multiplier 630 . Typically, if rounding up is required, a single unit value is added to the final summation output of the residue add and accumulate unit 630 , otherwise, a value of zero is added and the result is output.
Therefore, while the first F (fractional) digits do not directly affect the product summation, it may affect whether a round-up correction is made. During mixed radix conversion by Residue to Mixed Radix unit 610 , mixed radix digits are sent to the sign and round up detect unit 615 as shown in FIG. 6A . This unit is capable of comparing, digit by digit, whether the mixed radix value represented by the first F digits is greater than or equal to a pre-determined round-up threshold amount, i.e., such as 50% of the fractional range magnitude. If the final converted value requires rounding, a signal is sent from the round up detect unit 615 to the round up unit 635 to perform a round up on the summation value. If not, the round-up unit 635 outputs the input value unaltered. The value is then routed to bus selector unit 655 of FIG. 6A . Bus selector 655 will route the value to the final answer output 660 if the starting value 600 is positive, and hence smaller in magnitude than its complement value processed by mixed radix converter 620 . The final fractional multiplier result 660 is therefore a normalized positive fractional final product value.
As seen in FIG. 6A , the mixed radix converter 620 accepts the complement of the starting value 600 using complement unit 602 . In one embodiment, the mixed radix converter 610 executes in tandem with the mixed radix converter 620 . Both converters generate a mixed radix digit of the same significance (digit position) on each clock cycle. Since the values processed are complements, one value is larger than the other in magnitude. The sign and round up detect circuit 615 may detect which value converted is the smaller value in magnitude. If the smaller value is the complemented value 602 , this means the starting intermediate product was negative, and the value processed by converter 620 is therefore used. As before, converter 620 sends mixed radix digits to a power term multiplier unit 640 , which multiplies the mixed radix digit value by its power term constant, or weight. The power term constants are stored in a power terms source 625 . Each non-fractional digit processed adds another product sum to a running summation contained in the mixed radix digit, power term multiplier unit 640 as discussed previously.
After reconversion of the value back to residue format by the power term multiplier and accumulator 640 , the output may be rounded up by round up unit 645 . Unlike before, the value is then complemented by complement unit 650 , since the value processed is positive, and therefore must be re-converted to a negative quantity for a final result. During this time, regardless of the data path chosen, the sign flags, not shown, may be updated to reflect the proper sign, and the sign valid flags set true. Sign flags and sign valid flags are discussed in U.S. Patent Publication No. 2013/0311532.
The sign and round-up detect unit 615 determines if the original value or its complement is smaller in magnitude; it performs this comparison least significant digit first during conversion to mixed radix format. The sign and round-up detect unit 615 compares each mixed radix digit, digit by digit, during the synchronized conversion process. If a value under conversion terminates before another, that value is deemed smaller in magnitude. Also, if both converters terminate in the same cycle, the sign detect unit 615 can determine, based on the value of digits compared, which value is smaller in magnitude. Once detected, the sign detect unit 615 sends a signal to the select input of the bus selector 655 . In this embodiment, the fractional multiplier of FIG. 6A routes the correct answer to the output 660 , and furthermore, generates a valid sign flag for the resultant value.
In one embodiment, the residue to mixed radix conversion units 610 , 620 processes digit modulus from smallest to largest. This allows that every digit function unit only process digits within their specific legal range. For example, during subtraction of the digit value of the first modulus, its range is smaller than all other digit modulus; during subsequent processing of each successive digit, the same holds true. Therefore, the digit subtract unit of each digit processing unit of the residue to mixed radix converter, such as digit processing unit 1310 of FIG. 13 , need only support a single range modular subtract unit 1333 , using circuitry similar to that shown in FIG. 8 .
To illustrate one of the many variations of the fractional multiply method of the present invention, FIG. 6B is presented. In FIG. 6B , the identical apparatus as FIG. 6A is shown with several minor modifications. In FIG. 6A , two identical power terms sources 605 , 625 are illustrated. In FIG. 6B , the power terms source 625 b associated with the processing of the complement of the intermediate product 602 is modified to store a plurality of negative power terms, or pre-complemented power terms. The power terms source 605 b of FIG. 6B contains the original positive power terms, while the power terms source 625 b contains the complement of the original power terms, which is also referred to as negative power terms source 625 b . Lastly, the round-up unit 645 b is actually a decrement operation, since adding a negative one is subtracting by one.
Therefore, during the processing of the complement of the intermediate product 602 , the mixed radix digit, power term multiplier 640 multiplies a positive mixed radix digit with a negative power term value. This arrangement provides an apparatus where the mixed radix digit, power term multiplier 640 sums only negative weighted digit values. Therefore, the final resulting product sum of the power term multiplier 640 is already complemented, and there is no need for an extra complement step, such as complement step 650 of FIG. 6A . This arrangement saves a complement unit and a single clock cycle for the processing of negative fractional products. It also helps to make the fractional multiplier of FIG. 6B symmetrical in terms of timing regardless of the sign of the final fractional product result.
The following section presents a detailed operation of the fractional residue multiplier of the present invention by means of example. In this example, the same fractional problem presented in U.S. Patent Publication No. 2013/0311532, FIG. 15G, is presented for means of clear comparison, and this FIG. 15G is re-labeled FIG. 15 in the present disclosure. In the present example, the sample fractional value calculation is summarized within the dotted rectangle 1551 of FIG. 15. Of particular significance is the disclosure of the fractional format used in the present example, which may be deduced by examination of FIG. 15. In particular, the fractional format uses 18 distinct prime modulus, starting with the modulus M=2, and including every prime modulus up to modulus M=61.
The specific fractional range 1801 of the fractional representation of the present example is disclosed in FIG. 18 , and is based on the first seven primes, starting with M 0 =2 and ending with M 6 =17 inclusive. A whole number range, or integer range 1802 , is formed using the next four primes, M 7 =19 thru M 10 =31, and an extended range 1803 is formed using the remainder of the modulus M 11 =37 thru M 17 =61. A thorough description of the fractional format used in the present invention can be found in U.S. Patent Publication No. 2013/0311532.
In FIG. 16 , a control unit flow diagram is provided to illustrate the processing steps taken by the fractional multiplier of the present invention. The control flow will emphasize the apparatus of FIG. 6A over that of FIG. 6B for means of clarity. As mentioned earlier, the present invention does not disclose details of the control circuitry required to operate and sequence the apparatus of FIG. 6A , however, such control circuitry is well known to those skilled in the art. However, the flow diagram of FIG. 16 is also used to help describe the operation of the fractional multiplier of the present fractional multiply example which follows.
FIG. 17 is provided to clarify the contents and formation of power terms contained within the power terms sources 605 , 625 of FIG. 6A . Additionally, the pictorial table of FIG. 17 helps clarify various associations of the structure and operation of the power terms source with respect to the operation of the fractional multiplier of the present invention and example. In the present example, the power terms sources 605 , 625 are assumed to implemented using a memory LUT.
FIG. 18 and FIG. 19 are provided to illustrate the intermediate residue values of the example fractional multiply calculation in a digit by digit fashion. Associated with the residue intermediate values in FIG. 18 and FIG. 19 are the specific control steps of the flow control sequence of FIG. 16 . The example provided will focus on the multiplication of two positive fractional values in RNS fractional format. Multiplication of negative values use the opposite data path of FIG. 6A , and is similar to the flow described for positive results with the exception of two complement units 602 , 650 .
Starting with the flow diagram of FIG. 16 and the multiplier apparatus of FIG. 6A , the intermediate product (IP) is loaded into the mixed radix converter 610 in control step 1601 . This step is also shown in FIG. 18 , row 1808 which shows the actual starting intermediate product residue value. It should be noted that the intermediate product is the integer product of the two fractional operands A and B which is shown in FIG. 15 .
This initial integer multiply operation is typically considered part of the fractional multiply method, but has been left out of the control flow diagram of FIG. 16 . In this case, FIG. 16 may be more concisely described as a normalization flow control sequence, which is a more general procedure, and may be used to process an intermediate product sum value, for example.
In this example, operand A is the value 8.0625 as is shown in row 1556 of FIG. 15 , and operand B is the value 3.25 as shown in row 1557 of FIG. 15 . The integer product of these operands is shown in row 1558 of FIG. 15 , and is also repeated in FIG. 18 , row 1808 . Note that the digit modulus are shown in opposite order in FIG. 18 versus FIG. 15 . In control step 1602 of FIG. 16 , additional initialization takes place; the modulus index, [i], is cleared, and the accumulator section of each mixed radix digit, power term multiplier 630 , 640 of FIG. 6A is cleared. Also, the rounding comparator initial state flag “cFlag” is assigned as ‘equal’ initially. Note that in the example given, certain conventions are made. In particular, the modulus associated with the fractional residue digits, M 0 thru M 6 , and hence the fractional range, R F , are the first modulus to be divided out by the residue to mixed radix converters 610 , 620 . Therefore, the modulus associated with the fractional digits are numbered with the index [i] starting with zero.
In the next control step 1603 of FIG. 16 , a determination is made to whether either mixed radix converter contains a zero value. If not, the flow control proceeds to step 1604 which conveys the fact that the indexed modulus digit is stored, or at least transmitted to the mixed radix digit, power term multiplier 630 of FIG. 6A . This digit is in effect the generated mixed radix digit, d[i], output via bus 612 , 622 of FIG. 6A . In the next control step 1606 , the generated digit d[i] is subtracted from the entire RNS word contained in the residue to mixed radix converter 610 , 622 of FIG. 6A . Also, the entire residue value is also divided by the indexed modulus M[i]; this is performed using a multiply by the multiplicative inverse of the indexed modulus in one embodiment, as discussed earlier using the apparatus of FIG. 13 having a plurality of digit processing units similar to FIG. 12 . Next, in control step 1606 of FIG. 16 , a comparison or check is made to determine if the index is within the fractional digit range, and if so, flow control proceeds to control step 1609 , where the generated digit d[i] is compared against a rounding constant in mixed radix format. If the comparison is not equal, the state of the cFlag is updated to reflect the result of the digit comparison.
Proceeding forward to control step 1611 , the index [i] is incremented to anticipate the access and processing of the next modulus and digit position of the residue number under decomposition within the residue to mixed radix converter 610 , 620 of FIG. 6A . These aforementioned steps produce a new residue value in the residue to mixed radix converter, and this resulting value is shown in FIG. 18 , row 1809 by means of our example. Note that in FIG. 18 , row 1809 , the M 0 modulus digit position is shown with an asterisk, since the first modulus M 0 and its associated digit is now undefined, hence it is skipped as is shown in control step 1612 of FIG. 16 .
The process above is quite fast, and may be accomplished in one or two clock cycles in many embodiments. The above process is repeated for each and every modulus associated with the fractional range unless the residue value terminates in a zero value before that time. If so, unless the converted value is originally zero, or greater than the rounding constant, the final result will be an underflow. This type of result may generate an exception, or error, and is not shown in the control sequence of FIG. 16 for sake of clarity. In our example problem, the afore-mentioned process forms a loop, which is repeated for each additional fractional modulus M 1 thru M 6 of our example. In our example, this is illustrated in FIG. 18 , rows 1810 thru 1815 .
When all residue digits associated with the fractional range have been converted, and assuming the remaining non-skipped residue digits under decomposition are not all equal to zero, control is passed to control step 1603 , 1604 , 1605 of FIG. 16 , and then on to control step 1607 . This sequence of steps begins the conversion of residue digits not associated to the fractional range 1801 of FIG. 18 . In control step 1607 , the generated mixed radix digit d[i] is not associated with the fractional range, and is therefore sent to the mixed radix digit, power term multiplier 630 , 640 of FIG. 6A via data paths 612 , 622 respectively. In the next control step 1608 , the generated mixed radix digit d[i] is multiplied by its respective power term, or digit weight. For the very first non-fractional digit, this weight is equal to the value one, as shown in FIG. 1700 , row 1711 . The product of the digit and the value one is of course the value of the digit itself, and this product is summed to the value contained in the add and accumulate unit 1430 of FIG. 14 , which was cleared in control step 1602 of FIG. 16 . In FIG. 16 , control is again passed to control step 1611 and control step 1612 to increment the modulus index, and to skip the digit just processed. This process flow forms a loop which results in a residue value stored in the accumulator section 1430 of the mixed radix digit, power term multiplier of FIG. 14 . Note that the proper power term is always indexed within the power term source 1440 in this process. This index may be the same index [i] in some embodiments.
The above process forms a control loop which processes the first non-fractional residue digit d[7] in our example, and the relevant values generated during this process are shown in FIG. 18 , rows 1816 thru 1819 . The control loop for non-fractional digits repeats until one of the residue values contained in either mixed radix converter unit 610 , 620 goes to zero. In our example, there are four additional digits generated that are processed using the same control loop procedure, except with different power term values as shown in FIG. 19 , rows 1903 thru 1918 . At the end of the last non-fractional digit processing loop, the accumulator of the mixed radix digit, power term multiplier 630 contains the value 13376953 as shown FIG. 19 , row 1919 . Because our example uses positive values, the intermediate product associated with the product of our two initial operands A and B terminates before its complement, hence the comparison of the two decomposing IP values causes the control apparatus 615 of FIG. 6A to choose the upper data paths of the multiplier apparatus of FIG. 6A .
Furthermore, during the comparison of the fractionally associated mixed radix digits to the rounding constant c[i] of column 1806 of FIG. 18 , the last generated fractional digit d[6] is greater than the rounding constant digit c[6], so the cFlag of control step 1609 of FIG. 16 is set to “greater than” (>) in FIG. 18 , row 1815 , and this specifies that a round up is required; this fact is determined in control step 1613 of FIG. 16 . It should be noted that the cFlag of the comparison step 1609 may be generated not by a direct compare of two digits d[i] and c[i], but may be set by an early termination of one intermediate residue product over the other. In other words, if a residue value under decomposition by a residue to mixed radix converter 610 , 620 of FIG. 6A terminates before the other, i.e., its residue value goes to zero one or more digit positions earlier, then that value is deemed less in magnitude than the other. This slight complication is not specifically noted in the control flow of FIG. 16 , yet this condition may be a common occurrence.
In FIG. 19 , row 1918 , the accumulator of the mixed radix digit, power term multiplier 630 is sent to the round-up unit 635 in FIG. 6A . Because the cFlag is set “greater than” as noted above, the recomposed residue value from the accumulator section is incremented by one, thereby constituting a round up operation. In FIG. 19 , row 1919 , the final value is interpreted to be exactly the same result as that obtained in FIG. 15 using the method of mixed radix digit truncation of U.S. Patent Publication No. 2013/0311532, and re-printed as FIG. 15 .
In summary, the example demonstrates the improved fractional multiply method of the present invention, which essentially starts the residue re-composition process in parallel to the residue decomposition process, and this saves additional clock cycles in many embodiments.
B. Multiplier Method and Apparatus 2
The second claimed fractional residue multiplier achieves lower latency at the cost of additional parallel processing. The new method follows a different algorithm for fractional residue multiply then the previous disclosure. We will explain the basic algorithm first; next, we will show how the algorithm is applied to residue fractions and processed by the disclosed apparatus.
If we consider the multiplication of two fractional numbers, we can write the operation as:
w r .f r =w 1 .f 1 *w 2 .f 2 (eq. 1)
In equation 1, each fractional number is represented by a whole part, w, and a fractional part, f. We can also write a fractional value as the sum of its whole part and its fractional part:
w.f=w. 0+0 .f
Therefore, we can re-write equation 1 as:
w 1 .f r =( w 1 +f 1 )*( w 2 +f 2 )= w 1 w 2 +w 1 f 2 +w 2 f 1 +f 1 f 2 (eq. 2)
From equation 2, we have an integer operation, w 1 *w 2 , which in residue executes in two clocks including scaling by the fractional range. Two terms, w 1 f 2 & w 2 f 1 , which is a fraction multiplied by an integer, executes in a single clock cycle in residue format. The last term, f 1 f 2 , is the most problematic, as it represents a fraction times a fraction. One feature of the new multiplier is how this last term is processed in parallel to the process of separating the whole and fractional parts of each operand, w 1 .f 1 & w 2 .f 2 .
One motivation of the new method is to trade a fractional operation for several integer operations, which are faster in residue format. In terms of processing equation 2 in residue format, it is clear the separation of the whole and fractional portions of a fractional value is an important operation. In one embodiment, mixed radix conversion is used to perform such separation. Furthermore, base extension is an issue that must be dealt with.
FIG. 20 discloses a novel apparatus for separating a fractional residue number into its constituent fractional and whole parts. The fractional residue format for the example apparatus of FIG. 20 was introduced in U.S. Patent Publication No. 2013/0311532 and is not repeated here. In FIG. 20 , a mixed radix converter unit 2010 , which in one embodiment is similar to the apparatus of FIG. 13 , generates a mixed radix digit on each cycle. A power term multiplier and accumulator unit 2020 , which in one embodiment is similar to the apparatus of FIG. 14 , receives the mixed radix digit and multiplies by its associated power term 2015 , resulting in a weighted digit value. The power term multiplier and accumulator unit 2020 also includes an accumulator, which provides a means to provide a running accumulation of weighted digit values.
The mixed radix converter 2010 starts with the fractional residue digits first; after converting all fractional digits, a fractional range is converted. During the fractional range conversion, the weighted value of each digit output 2012 is summed by the power term multiply and accumulate unit 2020 . Immediately after all fractional digits are converted by the mixed radix converter 2010 , the power terms accumulator 2020 value is latched into the fractional portion latch 2025 . Next, the power term accumulator is cleared and the mixed radix conversion continues, only now the power terms accumulator is summing weighted digits associated with the whole, or integer, range. When mixed radix conversion terminates, the residue value contained in the power term multiply and accumulator 2020 is latched into the integer portion latch 2030 .
As shown in FIG. 20 , the apparatus for separating a fractional residue number into its fractional and whole parts includes a power terms constants source 2015 . FIG. 23 provides more detail of the power terms constants 2015 source by means of example. As shown, the power terms constants 2015 source of FIG. 23 illustrates an example structure which differs from the power terms source of FIG. 17 in that power terms for both the fractional range, and the whole integer range are provided. In FIG. 17 , only power terms for the whole range is supported, since the multiplier of the previous apparatus does not accumulate weighted digits of the fractional range by design. In the current fractional residue multiplier apparatus of FIG. 21 , power term constants are provided for both the fractional range, and the whole integer range of a residue fraction. The power term constants may be implemented as a memory look up table (LUT), or may be constructed using arithmetic circuits, not disclosed herein, which may dynamically calculate the required power terms constants depending on the fixed point position of a variable point position residue fraction. Variable point position residue fractions, also known as sliding point residue fractions, is disclosed in U.S. Patent Publication No. 2013/0311532 and is not repeated here.
In one embodiment, the total number of clocks required for the fractional residue value separation operation is the same as the total number of fractional and whole digits of a single operand. This is advantageous, since the number of clocks required to process the intermediate product of two residue fractional operands, i.e. in terms of converted mixed radix digits, may be double. Once the terms of equation 2 can be produced, it takes several additional clocks to scale and sum the integer and fractional portions, so in some cases, the algorithm of the present multiplier may multiply in less clock latency than the previous multiplier of the present invention. If a residue format supports both a large fractional and whole range, this new multiplier can reduce clock latency significantly. In fact, in terms of multipliers operating in a digit by digit fashion, this new apparatus may be one of the fastest procedures and methods known to date.
In order to reduce latency, the last fractional term f 1 f 2 of equation (2) must be processed quickly. One issue with this is that fully extended fractional values from the separators 2110 , 2120 of FIG. 21 are not ready until F number of clocks, where F is the number of fractionally associated residue digits. If the apparatus is to reduce clock cycles, this leaves only another W number of clocks to complete processing of the fractional value to gain any advantage. This is difficult, since the fractional result (f 1 *f 2 ) must be fully base extended before addition of the terms of equation (2) can be finalized.
One innovative method to speed up the processing of the fractional term (f 1 *f 2 ) of equation (2) relies on the fact that it is possible to truncate the fractional digits from the operands at start, and begin early processing of the fractional product. This innovation is disclosed next.
FIG. 21 illustrates an overall block diagram of the new fractional multiplier invention. The fractional portion multiplier 2130 receives two truncated fractional values via input bus 2106 and 2108 respectively. The truncated input contains only the fractional digits, and leaves all other digits undefined, or skipped. The reason is that simple truncation of the fractional digits of an operand does not produce a fully extended fractional residue value.
FIG. 22 illustrates a block diagram of one embodiment of the internal components of the fractional portion multiplier 2130 of FIG. 21 . In FIG. 22 , a multiply of the fractional digits of operand F 1 and F 2 is performed by integer multiplier 2205 . The result of multiplier 2205 results in a partially extended product which is steered by selector 2208 and then accumulated into a fully extended residue value using a residue to mixed radix converter 2210 feeding a power term multiply and accumulator unit 2220 . In one embodiment, the conversion process occurs one digit at a time, and when complete, the fully extended value, representing a truncated fractional product, is stored in a truncated fraction sum latch 2225 . In some other embodiments, the fully extended result by-passes latch 2225 and is routed directly to subtract unit 2240 .
At about the same time the base extension process above completes, the fully extended fractional values, Ext F 1 2237 and Ext F 2 2238 , are available from the fractional value separators 2110 and 2120 of FIG. 21 . As a result, information is available to allow the undefined digits originally produced by the multiplier 2205 to essentially ì catch-upî, or to be recovered, to where they would have been had they not been undefined. Mathematically speaking, the undefined digits are defined as caught up, or extended, if they assume the residue digit values which represent the fully extended product, (f 1 *f 2 ), divided by the fractional range R F . The definition of the fractional range R F is the product of all fractionally associated modulus, and is further defined in U.S. Patent Publication No. 2013/0311532.
To catch-up, or extend, the undefined (whole and redundant) digits, a fully extended product (f 1 *f 2 ) of the fractional values is obtained using multiplier 2235 in FIG. 22 . The source of the fully extended fractional values, Ext F 1 2237 and Ext F 2 2238 , is via fractional value separators 2110 and 2120 of FIG. 21 . These values are available F clock cycles from start. The fully extended value representing the product of the truncated fraction digits is subtracted from the fully extended product f 1 *f 2 using residue subtract unit 2240 shown in FIG. 22 . The result of subtraction unit 2240 is always a value that is evenly divisible by the fractional range R F , since all fractional residue digits are zero. The resulting value is multiplied by the multiplicative inverse of the fractional range (R F ) −1 2245 using multiplier 2250 , which occurs in a single step or clock. The resulting product of multiplier 2250 is defined for whole and redundant residue digits only (since the fractional range digits are undefined due to MODDIV by the fractional range R F ). The resulting whole and redundant digits represent the value of the normalized fractional portion product result (f 1 *f 2 ), but are partially base extended.
To form a completely extended normalized fractional product result, (f 1 *f 2 ), the resulting residue product value is routed to an available base extension unit. In one embodiment, the resulting digits are routed using bus 2252 to the same mixed radix unit converter 2210 using a bus selector 2208 . A new accumulator sum is started by clearing the power term accumulator 2220 . An associated set of power term constants are defined for this stage of conversion as shown in FIG. 23 . (For example, the power term constants 2215 restart at a power of one, and progress as a running product of digit modulus values, i.e., progressively scaled by the value of each modulus processed.) The non-skipped digits are converted to mixed radix, multiplied by their associated power, and are immediately summed to a running, but fully extended, residue value within the power term multiply and accumulator 2220 . The final sum represents the fully extended value of the partially extended product f 1 *f 2 result of multiplier 2250 .
When fully reconverted, the final fractional product (f 1 *f 2 ) is transferred from the power term accumulator 2220 to the final fractional result latch 2230 . In some embodiments, to save clock cycles, the final fractional result latch 2230 is replaced by a bus which transfers the result to the next stage of processing as indicated in FIG. 21 via bus 2132 .
Returning to FIG. 21 , a block diagram of one embodiment of the new multiplier is shown. Two fractional operands, represented as blocks 2102 , 2104 , are shown. One completely extended operand 2102 is input into fractional value separator 2110 while the other completely extended operand 2104 is input into fractional value separator 2120 at start. Also at start, fractional digits of the first and second operand are routed by bus 2106 and 2108 respectively, to one and another input of a fractional portion multiplier 2130 . At F number of clocks, value separators 2110 , 2120 output a fully extended fractional value to fractional portion multiplier 2130 . At F+W number of clocks, both value separators 2110 , 2120 output a fully extended integer value.
At this point, a plurality of integer multipliers 2140 , 2142 , 2144 , 2154 provide the first three of the four terms of the right side of equation 2. Multipliers 2140 , 2142 provide the product of an integer times a fraction. Adder 2150 performs a sum of these two terms. Multiplier 2144 provides a product of two integers, and further scales the product by the fractional range constant 2152 using multiplier 2154 . At approximately this point, the final term of equation 2 appears as a result of fractional portion multiplier 2130 , which is summed to the scaled whole term using adder 2156 . A final adder 2160 makes the final summation to complete the processing of the right hand side of equation 2. The final fractional multiply result exits adder 2160 in FIG. 21 .
Other embodiments may exist which basically accomplish the same functions as FIG. 21 . For example, a single multiplier and accumulator circuit may be used in lieu of multipliers 2140 , 2142 , 2144 & 2154 and adders 2150 , 2156 & 2160 . Other variations include modifications and enhancements to the residue fractional value separator of FIG. 23 . It should be clearly understood by those skilled in the art that variations to the multiplier apparatus illustrated by the block diagram of FIG. 15 are possible.
In the fractional multiplier apparatus of FIG. 21 , details for implementing a suitable rounding function is not shown for clarity. However, as shown in the fractional multiplier apparatus of FIG. 6 , a method for measuring the mixed radix digits associated with the fractional digits (of the IP) may be compared with a suitable rounding constant, and such a similar method may be implemented within the apparatus of FIG. 21 . In particular, and referring to FIG. 22 , during the mixed radix conversion (decomposition) of the fractional only product result of multiplier 2205 via the residue to mixed radix converter 2210 , the generation of a sequence of mixed radix digits output 2212 may also be transmitted to a comparator and control unit not shown. A comparator and control unit, similar to control unit 615 of FIG. 6 , may determine whether a round up is to be performed based upon a least significant first digit comparison to a rounding constant, similar to the rounding constant 1806 of FIG. 18 . In a similar method to steps 1808 thru 1815 of FIG. 18 , a comparison of mixed radix digits, or remainder value 1804 , is performed against a rounding constant 1806 . If the result of comparison determines the remainder value, associated to the value represented by the series of mixed radix digits 1804 , then the final residue result of the residue fractional multiplier of FIG. 21 may be incremented by one unit. It should be obvious to those skilled in arithmetic circuit design that other forms and modes of rounding is possible.
FIG. 24 is included to demonstrate an example calculation using the new residue fractional multiplier of the present invention. In this example, the same numeric operands and the same residue fractional format is used as provided in the example of FIG. 15 and FIGS. 18 & 19 for means of clear comparison. In row 2407 of FIG. 24 , the residue digits for operand A is shown, while in row 2408 the residue digits for operand B is shown. After performing a separation of the fraction portion from the whole, or integer portion, the fractional only portion for operand A is shown in row 2409 while the fractional only part of operand B is shown in row 2411 . Because the residue value separator apparatus of FIG. 20 produce completely extended operands, the residue values in rows 2409 , 2410 , 2411 , 2412 of FIG. 24 also show completely extended values.
In FIG. 24 , row 2413 shows the multiplication, or modulo product, of the fractional digits only of operand A 2407 and operand B 2408 . The remaining non-fractionally associated digits of row 2413 are shown with a dash, indicating that they are not used in this process. The fractional associated digits needed to form the product of operand A and operand B are therefore immediately available to the apparatus by a simple truncation of the fractionally associated operands A and B at start. The fractional portion multiplier of FIG. 24 then performs a base extension of the remaining digits using the residue to mixed radix converter 2210 and the power term multiply and accumulate unit 2220 . The result of this base extension may be stored in the truncated fractional sum register 2225 and this result is shown as row 2414 in our example calculation. By this time, a fully extended fraction portion has been separated from each operand A and B, and their product is calculated using the residue (integer) multiplier 2235 of FIG. 22 .
The difference of the fully extended truncated fraction product in register 2225 and the fully extended fraction only portions 2235 is performed using a subtract unit 2240 . This difference is shown in row 2416 of FIG. 24 . Note that this difference is evenly divisible by the fractional range, R F , whose value is also shown in row 2417 . Because of this, the remaining non-fractional digits of the fractional only product of row 2413 can be “caught up”, or calculated in one step, by multiplying the difference of row 2416 to the multiplicative inverse of the fractional range (with respect to the modulus of the number system). The result of this product, performed by multiplier 2250 of FIG. 22 , is shown in row 2419 of FIG. 24 . Note that the multiplicative inverse has no defined digits in the fractional range, so that the product will also not have valid, or defined, fractionally associated digits.
The product of row 2419 may be base extended by using the apparatus of FIG. 22 using the feedback path 2252 and another base extension cycle. The final base extended product is then stored in the final fractional result register 2230 . In this way, a fully normalized and extended fractional result, f 1 *f 2 , is calculated. This final value is shown in row 2420 of FIG. 24 . In rows 2421 and 2422 are the fractional times integer terms of equation 2, and in row 2423 is the product of the whole terms of equation 2 scaled (multiplied) by the fractional range R F . The final summation of these terms is accomplished using adder 2156 and adder 2160 . This result is shown in the row 2424 of FIG. 24 . This is the same final result of the previous multiplier examples, without the addition of one unit to account for a rounding operation.
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Methods and systems for residue number system based ALUs, processors, and other hardware provide the full range of arithmetic operations while taking advantage of the benefits of the residue numbers in certain operations.
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RELATED APPLICATIONS
This application claims the benefit of provisional patent application Ser. No. 61/596,930, filed Feb. 9, 2012, the disclosure of which is hereby incorporated herein by reference in its entirety.
FIELD OF THE DISCLOSURE
The present invention relates to microelectromechanical system (MEMS) switches, and in particular to pilot switch circuitry that reduces or eliminates arcing between MEMS switch contacts when the MEMS switch is opened or closed.
BACKGROUND
As electronics evolve, there is an increased need for miniature switches that are provided on semiconductor substrates along with other semiconductor components to form various types of circuits. These miniature switches often act as relays, generally range in size from a micrometer to a millimeter, and are generally referred to as microelectromechanical system (MEMS) switches.
In some applications, MEMS switches are configured as switches and replace field effect transistors (FETs). Such MEMS switches reduce insertion losses due to added resistance, and reduce parasitic capacitance and inductance inherent in providing FET switches in a signal path. MEMS switches are currently being deployed in many radio frequency (RF) applications, such as antenna switches, load switches, transmit/receive switches, tuning switches, and the like. For instance, transmit/receive systems requiring complex RF switching capabilities may utilize a MEMS switch.
With the incorporation of WLAN (wireless local area network) circuitry into smartphones, hot switching is no longer the exception but the rule. Hot switching occurs when a switch is switched (changes state from ON to OFF, or vice versa) while some voltage exists across the switch. Specifically, many modern “smartphones” have at least two antennas: a cellular antenna and a WLAN antenna. Thus, most cycles required of a MEMS contact switch (or other switch) attached to the cellular antenna will have hot switching power due to power received from the WLAN antenna. This hot switching may be fatal to contact switches. Conversely, hot switching occurs in switches connected to the WLAN antenna due to power received from the cellular antenna.
Thus, these two antennas are presently separate but co-located in the handset such that power from one network may be coupled to the adjacent network. The attenuation between these two adjacent radios can conservatively be 5 dB. It must be assumed by component manufacturers that these two radios are in continuous operation for the lifetime of the phone, from 5 to 10 years. The peak power from a WLAN radio is known to be +28.5 dBm. The power incident to all devices directly connected to the cellular radio antenna is therefore +23.5 dBm (after subtracting the 5 dB isolation). This level of power has been shown in characterization to limit the useful lifetime of MEMS contact switches to less than 1e6 cycles. However, the required lifetime number of cycles of such a switch used in an antenna switch exceeds 1e9 cycles and is calculated to be as many as 130 B cycles.
Furthermore, MEMS contact switches are known to have a low tolerance for ESD (electro static discharge) stresses with HBM (human body model) durability not exceeding 150 V in most cases compared to a specification requirement of 250 V. No MEMS contact switch has ever been exposed to the 8 k contact discharge test common to handset ESD reliability requirements. But it is possible that a MEMS contact switch would fail this test even with the typical decoupling capacitor and shunt inductor in place.
Turning to FIGS. 1A and 1B , a MEMS device 10 having a main MEMS switch 12 is illustrated according to the prior art. The main MEMS switch 12 is formed on an appropriate substrate 14 . The main MEMS switch 12 includes a cantilever 16 , which is formed from a conductive material, such as gold. The cantilever 16 has a first end and a second end. The first end is coupled to the substrate 14 by an anchor 18 . The first end of the cantilever 16 is also electrically coupled to a first conductive pad 20 at or near the point where the cantilever 16 is anchored to the substrate 14 . Notably, the first conductive pad 20 may play a role in anchoring the first end of the cantilever 16 to the substrate 14 as depicted. The first conductive pad 20 may form a portion of or be connected to a first terminal (not shown) of the main MEMS switch 12 .
The second end of the cantilever 16 forms or is provided with a cantilever contact 22 , which is suspended over a terminal contact 24 formed or provided by a second conductive pad 26 . The second conductive pad 26 may form a portion of or be connected to a second terminal (not shown) of the main MEMS switch 12 . Thus, when the main MEMS switch 12 is actuated, the cantilever 16 moves the cantilever contact 22 into electrical contact with the terminal contact 24 of the second conductive pad 26 to electrically connect the first conductive pad 20 to the second conductive pad 26 . The main MEMS switch 12 may be encapsulated by one or more encapsulating layers 30 , which form a substantially hermetically sealed cavity around the cantilever 16 . The cavity is generally filled with an inert gas and sealed in a near vacuum state. Once the encapsulation layers 30 are in place, an overmold 32 may be provided over the encapsulation layers 30 .
To actuate the main MEMS switch 12 , and in particular to cause the cantilever 16 to move the cantilever contact 22 into contact with the terminal contact 24 of the second conductive pad 26 , an actuator plate 28 is formed over a portion of the substrate 14 , preferably under the middle portion of the cantilever 16 . To actuate the main MEMS switch 12 , an electrostatic voltage is applied to the actuator plate 28 . The presence of the electrostatic voltage creates an electromagnetic field that effectively moves the cantilever 16 against a restoring force toward the actuator plate 28 from an “open” position illustrated in FIG. 1A to a “closed” position illustrated in FIG. 1B . Likewise, removing the electrostatic voltage from the actuator plate 28 releases the cantilever 16 for return to the open position illustrated in FIG. 1A . As illustrated, the open position occurs when the cantilever contact 22 is out of contact with the terminal contact 24 , and the closed position occurs when the cantilever contact 22 comes into contact with the terminal contact 24 . Other embodiments may differ.
In light of the electromechanical structure of the main MEMS switch 12 , the main MEMS switch 12 cannot provide switching action as fast as typical solid state switches, such as n-type metal-oxide-semiconductor (NMOS) FET switches. The switching time of the main MEMS switch 12 typically depends upon the electromagnetic field applied to the cantilever 16 , the mass of the cantilever 16 , and the restoring force of the cantilever 16 . However, an FET switch may generate higher insertion loss than is generated by the main MEMS switch 12 . Moreover, at high power levels in an RF circuit (not shown), parasitic capacitance at the semiconductor junctions of the FET switch may alter RF signals.
During switching events, a difference in potential between the cantilever contact 22 and the terminal contact 24 may cause an electrical arc resulting from an electrical current flowing through normally non-conductive media, such as air. Undesired or unintended electrical arcing may have detrimental effects on the cantilever contact 22 and the terminal contact 24 of the main MEMS switch 12 . For instance, as the main MEMS switch 12 is being either actuated to the closed position of FIG. 1B or released to the open position of FIG. 1A , arcing from a difference in potential between the cantilever contact 22 and the terminal contact 24 may cause significant aging, unintended wear and tear, degradation, sticking, or destruction of the cantilever contact 22 , the terminal contact 24 , or both. Unintended power dissipation through arcing should be limited for optimum contact lifetime of the cantilever contact 22 and the terminal contact 24 .
Therefore, it is evident there is a need to reduce the amount of power incident to switches connected to a cellular antenna and particularly to MEMS contact switches which are connected to a cellular antenna in order that their lifetimes can be extended to cover the lifetime cycle requirements for this application and make available their extremely low loss and high linearity.
Decreasing the amount of power incident to these switches minimizes arcing, and thus decreases switch contact aging, degradation, sticking, and destruction. In order to utilize the low loss and high linearity possible with MEMS, some means to attenuate the power must be introduced.
Furthermore, there is a need to provide some improved tolerance in these same MEMS contact switches to ESD stresses which can occur as a result of their installation at the antenna of a mobile handset.
SUMMARY
The present disclosure relates to the addition of a pilot switch shunt branch to a common port (such as a “hot node” or an “RF injection node” of a MEMS contact or other switch) to attenuate power entering the switch through the common port during switching events. If the pilot switch is made in solid state, it can switch quickly and additionally offer ESD protection for the switch network it precedes.
In one embodiment, the pilot switch includes a solid state switch in series with a MEMS switch.
In one embodiment, two MEMS switches are transitioned substantially simultaneously during a period when the pilot switch shunts the hot node to ground.
In one embodiment, two MEMS switches are transitioned sequentially during a period when the pilot switch shunts the hot node to ground.
Those skilled in the art will appreciate the scope of the present disclosure and realize additional aspects thereof after reading the following detailed description of the preferred embodiments in association with the accompanying drawing figures.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying figures incorporated in and forming a part of this specification illustrate several aspects of the disclosure, and together with the description serve to explain the principles of the disclosure.
FIGS. 1A and 1B illustrate a microelectromechanical system (MEMS) switch in an open and closed position, respectively, according to the prior art.
FIGS. 2A , 2 B, and 2 C illustrate a solid state pilot switch linking a hot node to a ground.
FIG. 3 illustrates a solid state pilot switch in series with a MEMS pilot switch, linking a hot node to a ground.
FIG. 4 illustrates a bypass resistor R 1 in parallel with one of the MEMS.
FIG. 5 illustrates a two die configuration.
FIG. 6 illustrates simultaneous switching for two MEMS.
FIG. 7 illustrates sequential switching for two MEMS.
FIG. 8 illustrates exemplary calculations for a maximum resistance of the pilot switch.
FIGS. 9A and 9B illustrate power flows effects due to a pilot switch.
DETAILED DESCRIPTION
The embodiments set forth below represent the necessary information to enable those skilled in the art to practice the embodiments and illustrate the best mode of practicing the embodiments. Upon reading the following description in light of the accompanying drawing figures, those skilled in the art will understand the concepts of the disclosure and will recognize applications of these concepts not particularly addressed herein. It should be understood that these concepts and applications fall within the scope of the disclosure and the accompanying claims.
FIGS. 1A and 1B illustrate a microelectromechanical system (MEMS) switch in an open and closed position, respectively, according to the prior art. See Background section for additional discussion.
FIG. 2A illustrates a solid state pilot switch linking a hot node to a ground. Control circuitry 38 controls: transmitters 34 , MEMS switches 42 , receivers 33 , and pilot switch circuit 48 A. Control circuitry 38 may be logically organized into the following portions (not shown): transmitter control circuitry, MEMS switches control circuitry, receiver control circuitry, and pilot switch control circuitry. In the embodiment of FIG. 2A , a pilot switch circuit 48 A includes a solid state pilot switch SW 1 that links (connects) the hot node N 1 to a ground GND. The solid state pilot switch SW 1 is controlled by at least one control input node NSW 1 . Other embodiments of the pilot switch circuitry 48 A are discussed later.
Hot node N 1 is often called an “injection node,” and may be linked to antenna ANT 1 , or to a cable input (not shown). Hot node N 1 may or may not have voltage at any given time. Antenna ANT 1 is subject to receiving transmissions or interference INT (shown as a lightning bolt icon) from second antenna ANT 2 . Second antenna ANT 2 may belong to another device or may belong to the same device. In one embodiment, ANT 1 is a cellular antenna and ANT 2 is a WLAN (wide local area network) antenna, and both antennas are located in a single handheld communication device (this is a common configuration that causes many interference problems).
FIG. 2B illustrates exemplary MEMS switches 42 in more detail. Specifically, in FIG. 2B MEMS switches 42 include a SPNT (Single Pole, N Throw) switch set on a single die. In this case, there are 14 MEMS switches, so N=14, and this is a SP14T (single pole, 14 throw) switch set. The N 1 node can be “thrown” to any of 14 nodes labeled M 1 through M 14 . In one embodiment, a first set of MEMS switches 44 is linked to various cellular transmission circuits (see transmitters 34 in FIG. 2A ), and a second set of MEMS switches 46 is linked to various cellular receiving circuits (see receivers 36 in FIG. 2A ).
The proper use of the pilot switch SW 1 in pilot switch circuitry 48 A would be to close (change from a high impedance to a low impedance state) the pilot switch SW 1 before a state change (open->close or close->open) of any of the connected MEMS switches (M 1 -M 14 ). The pilot switch SW 1 is controlled by node NSW 1 .
FIG. 2C illustrates control circuitry 38 controlling MEMS switch M 12 through node NM 12 , and controlling pilot switch SW 1 through control node NSW 1 .
FIG. 3 illustrates a solid state pilot switch in series with a MEMS pilot switch, linking a hot node to a ground. FIG. 3 is identical to FIG. 2B , except that pilot switch circuit 48 B includes a MEMS pilot switch M 15 in series with solid state pilot switch SW 1 . The timing of these pilot switches will be discussed below in relation to other figures. The order of MEMS pilot switch M 15 in series with solid state pilot switch SW 1 may be reversed (not shown), so that the MEMS pilot switch M 15 may be on the ground side of the solid state pilot switch. Further, a resistor (not shown) may be inserted into this series.
The addition of a MEMS pilot switch in series with the solid state pilot switch eliminates the negative impact of the OFF capacitance and limits the impact of the non-linearity of the solid state device. On the minus side, the total transition time required now includes 1.5 MEMS cycles plus 1 solid state switch cycle. Also, the MEMS pilot switch may be less protected from power incident on the common port.
FIG. 4 illustrates a bypass resistor R 1 in parallel with one of the MEMS. FIG. 4 is identical to FIG. 3 , except that a bypass resistor R 1 has been placed in parallel with MEMS switch M 8 . A bypass resistor R 1 may be used in combination with pilot switch circuitry such as 48 B, or may be used by itself (not shown) without pilot switch circuitry.
FIG. 5 illustrates a two die configuration. In FIG. 5 , a first die D 1 includes a SP14T (Single Pole, 14 Throw) switch set 42 with 14 MEMS switches and a contact pad N 1 A. This is a common commercial die.
Die D 2 includes pilot switch circuitry 48 C (or 48 B, not shown), and control circuitry CC for controlling the solid state pilot switch S 21 (and optionally the MEMS pilot switch, not shown). Die D 2 includes contact pads N 1 B and N 1 C.
Antenna ANT 1 is linked to contact pad N 1 D.
In the two die configuration of FIG. 5 , contact pads N 1 A and N 1 B are bonded together using bond wire B 1 , contact pads N 1 B and N 1 C are contacted together internally inside of die D 2 , and contact pads N 1 C and N 1 D are bonded together using bond with bond wire B 2 .
After the bond wires are attached, contact pads N 1 A, N 1 B, N 1 C, and N 1 D all form a single hot node N 1 (not shown).
In this embodiment, a single die D 2 is conveniently inserted between the commercial SP14T die D 1 and the antenna ANT 1 . This single die D 2 contains both the pilot switch 48 C and the associated control circuitry CC. Thus, this embodiment is very efficient to implement in production.
FIG. 6 illustrates simultaneous switching for two MEMS. The MEMS switch state transitions can be coincident or occur in any beneficial order. In FIG. 6 , the MEMS switch transitions occur simultaneously. The order of MEMS switch transitions may be adjusted as required by an application, and all such variations are considered to be within the scope of the present disclosure.
Of course any number of switches attached to the hot node may transition in any particular order (or simultaneously) during the single pilot switch cycle (Off/On/Off). And of course it is also possible to use more than one pilot switch Off/On/Off cycle if needed or if it is advantageous to switch multiple MEMS switches.
In FIG. 6 , a switching sequence illustrates simultaneous switching for two MEMS (M 1 and M 2 ) while pilot switch SW 1 grounds hot node N 1 .
Graph G 1 illustrates pilot switch SW 1 turning on at time T 1 , thus grounding hot node N 1 . Switch M 1 transitions from On to Off at time T 2 , and switch M 2 transitions from Off to On simultaneously at time T 2 (while the hot node N 1 is grounded). Later, at time T 3 , the pilot switch SW 1 turns off, and isolates hot node N 1 from ground GND.
For example, before time T 1 , switch M 1 may be connected to a transmission circuit (not shown), and may be conducting a transmission signal to an antenna (not shown) through hot node N 1 . After time T 3 , switch M 2 may be connected to a receiving circuit (not shown), and may be conducting a received signal from an antenna (not shown) through hot node N 1 to the receiving circuit (not shown). In other words, this switching sequence may represent a change from transmitting to receiving by a cellular telephone.
Alternatively, this switching sequence may represent: a change from receiving to transmitting by a cellular telephone; or a change from transmitting in a first band (through M 1 ) to transmitting in a second band (through M 2 ); or a change from receiving in a first band (through M 2 ) to receiving in a second band (through M 2 ). In all of these cases, grounding hot node N 1 during the transitions of MEMS switches increases the lifespan of the MEMS switches.
Circuit CKT 1 shows the MEMS switches before transitioning, and circuit CKT 2 shows the MEMS switches after transitioning.
If the pilot switch 4 A is replaced by a pilot switch that includes a solid state pilot switch and a MEMS pilot switch (as shown in pilot switch 48 B in FIG. 4 ), then switching the pilot switch requires that both the solid state pilot switch and the MEMS switch are switched.
In one embodiment, switching pilot switch 48 B (not shown) ON includes first switching the MEMS pilot switch ON, then switching the solid state pilot switch ON (this grounds hot node N 1 ). While the hot node is grounded, other MEMS switches are transitioned, either simultaneously or sequentially. Switching the pilot switch 48 B OFF includes first switching the solid state pilot switch OFF, then switching the MEMS pilot switch OFF (this isolates hot node N 1 from ground).
Alternatively (not shown), the pilot switch may be turned ON, MEMS switch M 1 transitioned, the pilot switch turned OFF, then the pilot switch may be turned ON, MEMS switch M 2 transitioned, and the pilot switch turned off. This alternative is not very efficient from a timing point of view. It is more efficient to transition M 1 and M 2 simultaneously as shown in FIG. 6 , or sequentially (but during a single cycle of the pilot switch) as shown in FIG. 7 below.
FIG. 7 illustrates sequential switching for two MEMS. FIG. 7 is identical to FIG. 6 , except that MEMS switch M 2 transitions from OFF to ON at time T 5 , and time T 5 is different from time T 2 (but during a single cycle of the pilot switch). Thus, switch M 2 transitions sequentially with respect to switch M 1 (and not simultaneously as shown in FIG. 6 ).
Sequential switching of the MEMS switches has some advantages in comparison to simultaneous switching. Sequential switching reduces the maximum switching power requirements, because only one switch must be transitioned at a time.
If the pilot switch 4 A is replaced by a pilot switch that includes a solid state pilot switch and a MEMS pilot switch (as shown in pilot switch 48 B in FIG. 4 ), then switching the pilot switch requires that both the solid state pilot switch and the MEMS switch are switched. One possible switching sequence for pilot switch 48 B was discussed above in relation to FIG. 6 .
FIG. 8 illustrates exemplary calculations for a maximum resistance of a pilot switch in a 50 ohm system, for a power reduction of 13.5 dBm.
Assuming that a cellular antenna receives 23.5 dBm peak power from a nearby WLAN antenna, and allowing a design maximum of 10 dBm to reach the SP14T MEMS switches through the hot node, means that the pilot switch must attenuate the WLAN signal by 13.5 dBm (23.5−13.5=10).
Graph G 3 plots Gain versus Resistance Rshunt for a simulated circuit similar to FIG. 2 . The gain reaches −13.5 (an attenuation of 13.5) at dB1, corresponding to a resistance R 1 of 6.7 ohms. Thus, as a design parameter, the pilot switch should have a resistance of 6.7 ohms or less when ON (when grounding the hot node).
FIGS. 9A and 9B illustrate power flow effects due to a pilot switch.
In FIG. 9A , pilot switch 48 D is open, antenna ANT 1 receives 23.5 dBm from a nearby WAN antenna (not shown), transmission circuit CKT 3 is transmitting at 35 dBm through MEMS switch M 5 .
In FIG. 9B , pilot switch 48 F is closed (providing an attenuation of 13.5 dBm for a 6.7 ohms resistance to ground), antenna ANT 1 receives 23.5 dBm from a nearby WAN antenna (not shown), and 10 dBm of power reaches MEMS switch M 5 .
Those skilled in the art will recognize improvements and modifications to the preferred embodiments of the present disclosure. All such improvements and modifications are considered within the scope of the concepts disclosed herein and the claims that follow. In the claims, the term “solid state switch” refers to any semiconductor device capable of acting as a switch, including, but not limited to: field effect transistors (FET), complementary metal oxide semiconductors (CMOS), and so forth.
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Pilot switch circuitry grounds a hot node (an injection node) of a microelectromechanical system (MEMS) switch to reduce or eliminate arcing between a cantilever contact and a terminal contact when the MEMS switch is opened or closed. The pilot switch circuitry grounds the hot node prior to, during, and after the cantilever contact and terminal contact of the MEMS come into contact with one another (when the MEMS switch is closed). Additionally, the pilot switch circuitry grounds the hot node prior to, during, and after the cantilever contact and terminal contact of the MEMS disengage from one another (when the MEMS switch is opened).
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The United States of America may have certain rights to this invention under Management and Operating contract No. DE-ACO5-060R23177 from the Department of Energy.
FIELD OF THE INVENTION
1) This invention relates to cardiac imaging and more particularly to a cardiac imaging system using dual gamma imaging heads co-registered with one another to provide two dynamic simultaneous views of the heart region.
BACKGROUND OF THE INVENTION
2) Cardiac imaging and functional analysis is the largest single nuclear medical imaging application and represents the area of greatest unmet need in the current technology. Physicians require information on the anatomy and function of the heart in order to diagnose, prescribe treatment, and monitor results of intervention.
3) First-Pass Radionuclide Angiography (RNA) provides the clinician with patient information for improved patient management that is either difficult and/or costly to obtain using other technologies. First-Pass RNA procedures have substantial underutilized potential to be used as early diagnostics for coronary artery disease and myocardial infarctions. The speed and ease of administration of the First-Pass RNA diagnostic procedures allow for new use environments such as the Emergency Room environment or in outpatient cardiology clinics, First-Pass RNA can provide unique dynamic information about cardiac function, such as regional ventricular wall motion, ventricular ejection fraction, pulmonary transit-time, contractility, and shunt quantitation.
4) Currently single gamma (non-PET) nuclear medicine cardiac imaging (both tomographic SPECT procedure and planar imaging procedures) is performed with standard nuclear medicine cameras. These procedures are either performed with standard gamma cameras or with newly introduced dedicated fast rate gamma cameras (from Digirad, GVI). Both types suffer from rather poor sensitivity to detect heart abnormalities located in the further part of the heart, away from the chest wall, hence far from the closest possible approach of the camera surface. There are two contributing factors to this limited sensitivity performance related to the basic physics principles of single gamma imaging: (1) spatial resolution that decreases with distance between the heart sector and the detector head as a result of the collimator, and (2) the dominating effect of gamma ray absorption and scattering in the heart tissue and other body organs on its way towards the detector as a consequence of tissue absorption. A single compact dedicated cardiac detector allows placement of the detector directly against the chest wall and thus improves spatial resolution by minimizing the distance to heart. But this will not help with the absorption issue.
5) In the SPECT case, during the tomographic acquisition of series of images from different detector head positions around the patient torso, each sector of the heart has better visibility from some directions of closest approach to that sector (with the exception of the inner sector of the heart equally distant from all directions). In addition, computer algorithm-based modeling of the absorption and spatial resolution effects and subsequent correction of the collected data is improving the quality of reconstructed 3D data. However, the situation is diametrically different during planar imaging, and especially during the dynamic first-pass procedure, when imaging is performed from only one pre-selected imaging direction (one view) and only limited post-acquisition corrections are possible.
6) In addition to first-pass imaging, a practical and most useful imaging cardiac system should be also able to perform other imaging procedures. Some imaging procedures that will benefit from the proposed improvement in the imager include: (1) 1st pass studies, (2) planar, EKG-gated (and non-gated) bloodpool (MUGA) studies, which encompasses extensive phase analysis of the wall motion during heart cycle to appreciate potential damage to the heart muscle, (3) planar EKG-gated (and non-gated) perfusion studies, (4) planar hot spot imaging, and (5) limited positron detection via planar acquisition.
7) Planar gated (MUGA) studies are used to evaluate ventricular wall motion, and elucidate an ejection fraction based on the systolic and diastolic filling (of blood) within the ventricle. Planar perfusion studies are used to evaluate blood flow to the myocardium (left ventricle) and are quantified by established algorithms. Hot spot imaging involves detection only in areas of unique radiotracer uptake, which are higher than background. Although not widely accepted yet, positron imaging of the heart capitalizes on the ability to image metabolism and blood flow within the heart. One of the implementations of the proposed system will have the capability to perform positron imaging studies using the same detector heads but with removed collimators and operating in a coincidence mode. However, this additional function is not at the core of the present invention, which is focusing solely on improvement of single gamma imaging capability.
8) Tc-99m is the most popular label used in nuclear medicine and is in the energy range (140 keV). The major problem associated with the single-view planar (such as firstpass) cardiac imaging procedure is that the characteristic gamma radiation from Tc-99m undergoes substantial absorption when traversing tissues such as heart muscle tissue. As a result for Tc-99m, the gamma ray flux, and the associated imaging signal in the gamma camera, coming from the region of the heart away from the detector is much more attenuated than the gamma rays originating in the front part of the heart. This signal sensitivity asymmetry, can produce an effect equivalent to a less pronounced cardiovascular flow at the back side of heart, and, therefore, provides less diagnostic power as to the quality of the cardiovascular flow in that region. On a statistical basis, this asymmetry effect results in a less pronounced separation between the healthy individuals and people who have cardiovascular disease.
9) Alternative imaging labels with higher-energy gamma emissions undergoing lower absorption in the heart tissue, such as I-131 and In-113m, have been used in the past with success, but are not used in today's clinical environment, are not being manufactured in volume, and produce higher patient doses. Subject of our invention is a partial but substantial remedy to the theoretically expected and clinically observed limitation in the detection of Tc-99m gamma emission from the patient's heart which is adversely impacting the diagnostic quality of all single gamma imaging modalities but especially of the dynamic imaging of a kind performed during the firstpass procedure.
10) The dual-head cardiac imaging system proposed herein will have the following novel features to improve cardiac imaging and functional analysis:
(1) two identical compact light-weight gamma imaging detector heads, mounted on a gantry, will be precisely mechanically co-registered to each other at 180 degrees (placed opposite to each other), placed on both sides of the patient torso and fixed relative to each other, with the patient's heart encompassed by the resulting active field of view, (2) Two high precision specially designed and produced parallel hole collimators (made out of lead, tungsten, lead alloy, tungsten alloy, or mixtures of lead or tungsten powder with filling materials such as epoxy) will be precisely mechanically aligned, and the alignment will be checked using special QA procedure with line or point Co-57 radioactive sources before each patient scan, (3) Two individually produced time series of dynamic cardiac images in both detector heads will be obtained using the same start time and time clock, and will be processed as one set of time correlated images by special imaging algorithms involving multiplication of pre-processed co-registered images from both imagers for each time frame.
SUMMARY OF THE INVENTION
6) The invention is a cardiac imaging system that employs dual gamma imaging heads co-registered with one another to provide two dynamic simultaneous views of the heart sector of a patient torso. The imaging system includes a first gamma imaging head in a first orientation with respect to the heart sector and a second gamma imaging head in a second orientation with respect to the heart sector. Each gamma imaging head is in close proximity to the patient torso and in alignment with the heart sector. An adjustment arrangement is provided for adjusting the distance between the separate imaging heads and the angle of one head with respect to the other. By adjusting the angle between the imaging heads to 180 degrees and operating in a range of 140-159 keV at a rate of up to 500 kHz, the imaging heads can be co-registered. The imaging system will produce simultaneous dynamic recording of two stereotactic views of the heart thereby providing depth information to disentangle contributions from overlapping sections of the heart. The pixel values of the two co-registered images obtained in the same time bin are multiplied on a pixel-by-pixel basis, resulting in a single product image per each time bin (pixel-by-pixel) series of dynamic images obtained from the two opposed gamma imaging heads. The use of co-registered imaging heads maximizes the uniformity of detection sensitivity of blood flow in and around the heart over the whole heart volume and minimizes radiation absorption effects. A normalization/image fusion technique is implemented pixel-by-corresponding pixel to increase signal for any cardiac region viewed in two images obtained from the two opposed detector heads for the same time bin.
OBJECTS AND ADVANTAGES
7) Several advantages are achieved with the cardiac imaging system of the present invention, including:
(1) Improved diagnostic power over conventional nuclear medicine cardiac systems. (2) A combined image having improved spatial resolution and contrast over prior art methods. (3) A combined image that greatly improves detection of the signal from the left coronary system thereby providing an image of all three coronaries. (4) Increased imaging sensitivity over convention imaging systems permits detection of heart abnormalities in the further part of the heart. (5) A significant decrease in undesirable background outside the small features of interest such as coronary arteries, hot spots or plaques. (6) An improvement in combined image normalization by using a combined flood image obtained from the flood images of the two gamma imagers and implemented by using a novel image combination algorithm. (7) Improved 1st pass studies of the target region as a result of the high rate capability of the imaging system. (8) Enhanced phase analysis of the wall motion during heart cycle to appreciate potential damage to the heart muscle, including planar, EKG-gated (and non-gated) bloodpool (MUGA) studies. (9) Improved planar EKG-gated (and non-gated) perfusion studies. (10) Enhanced planar hot spot imaging. (11) Better positron detection via planar acquisition. (12) Elimination of the gamma absorption effect inherent in prior art single gamma imaging systems. (13) Elimination of the feature overlap inherent in prior art single gamma imaging systems. (14) The ability to observe two simultaneous dynamic views of the heart region by using a system employing two sets of co-registered detector heads used in a stereotactic way. (15) An improved method of producing two stereotactic views with one set of co-registered detector heads by timely two-step injection of the bolus with each view dynamic image associated with one injection and a specialized background-subtracting algorithm applied to the second view position. (16) A significant reduction in the large dead zones between the individual PSPMTs in the array of photomultiplier tubes by implementation of optimized optical coupling involving a spreader window and reflective strips installed in the dead zones.
8) These and other objects and advantages of the present invention will be better understood by reading the following description along with reference to the drawings.
DESCRIPTION OF THE DRAWINGS
9) FIG. 1 is a conceptual view of a cardiac imaging system according to the present invention using dual gamma imaging heads co-registered with one another to provide two dynamic simultaneous views of the heart region.
10) FIG. 2 is a conceptual view of gamma camera head construction based on an array of 16 flat PSPMTs.
11) FIG. 3 is a conceptual view of a mechanically co-registered opposed dual-head single gamma imager placed at 30 deg RAO (Right Anterior Oblique) position relative to the patient's heart.
12) FIG. 4 is a conceptual view of a second embodiment having two pairs of compact co-registered gamma imagers providing a stereotactic view of the heart and region around the heart.
13) FIG. 5 depicts the normalized energy spectra (detector 1 —left, and detector 2 —right) obtained during a capillary alignment run of the cardiac imager system of the present invention.
14) FIG. 6 depicts the phantom images from the (from left to right in the figure) detector 1 , detector 2 , and the combined (after mechanical and software alignment).
15) FIG. 7 depicts a Y-strip X-coordinate projections from detector 1 (at left), detector 2 (center), and the combined image (at right).
16) FIG. 8 depicts the processed images from the front detector 1 (image at left), back detector 2 (image in the middle), and combined (at right) for the first experimental setup.
17) FIG. 9 shows the contrast values for the longitudinal profile plots corresponding to the three images of FIG. 8 .
18) FIG. 10 depicts the raw image and longitudinal profile obtained in the first detector (detector 21 in FIG. 1 ) for the second experimental setup.
19) FIG. 11 depicts the raw image and longitudinal profile obtained in the second detector (detector 22 in FIG. 1 ) for the second experimental setup.
20) FIG. 12 depicts the combined image and longitudinal profile obtained from both detectors for the second experimental setup.
21) FIG. 13 is a combined image and longitudinal profile after normalization of the combined image by the combined flood image.
22) FIG. 14 depicts the three images as shown in FIGS. 10-12 but after software smoothing has been applied.
23) FIG. 15 depicts smoothed resulting images from the front detector for the third experimental setup.
24) FIG. 16 depicts smoothed resulting images from the back detector for the third experimental setup.
25) FIG. 17 depicts the combined image for the third experimental setup.
INDEX TO REFERENCE NUMERALS IN DRAWINGS
20
co-registered opposed dual-head single gamma imager
21
gamma imaging head
22
gamma imaging head
24
parallel-hole collimator
26
patient torso
28
heart segment or heart sector
30
flat PSPMT
32
optical spreader window
34
scintillation array
36
window
38
reflective strip
40
heart
41
gamma imaging system, second embodiment
42
gamma imaging head
44
gamma imaging head
d
depth in cm of the heart sector below the surface of the heart
t
acquisition time in seconds
T
heart thickness in cm in the relevant projection plane and direction
μ
linear attenuation coefficient of heart tissue in cm −1
DETAILED DESCRIPTION OF THE INVENTION
26) The proposed invention is a system implementing two identical and opposed co-registered detector heads placed on both sides of patient's chest to provide absorption-corrected imaging for a first-pass cardiac imaging procedure. The geometry used for co-registered dual-sided imaging according to this invention is shown in FIG. 1 . The co-registered dual-sided imager 20 includes two identical gamma cameras 21 and 22 with identical and co-linear parallel-hole collimators 24 placed on opposite sides of a patient torso 26 . If the total radioactivity in the heart segment 28 is A, then following simultaneous acquisition of the two planar images, the number of gamma rays detected by each camera from that heart segment 28 is approximated by the following relationship:
N 1 =ε 1 tA exp[−μd] N 2 =ε 2 tA exp[−μ( T−d )] (1)
where ε 1 and ε 2 are the practical detection efficiencies of cameras 1 and 2 respectively (including absorption in other than heart tissue, such as lungs, bones, etc), t is the acquisition time in seconds, μ is the linear attenuation coefficient of heart tissue in cm −1 , d is the depth in cm of the heart sector below the surface of the heart and camera 1 surface, and T is the heart thickness in the relevant projection plane and direction, in cm.
27) Each camera 20 and 22 provides a different assessment of the heart sector dynamic activity, both of which are lowered by the attenuation effect. However, if the pixel values of the two co-registered images obtained in the same time bin are multiplied on a pixel-by-pixel basis, resulting in a single product image per each time bin, then the product image gives the following for the signal value from the heart segment of interest:
N 1 N 2 =ε 1 ε 2 t 2 A 2 exp[−μT] (2)
28) Equation (2) shows that the effect of heart segment depth d is removed from the formula, with the remaining absorption effect expressed by the heart thickness T at that heart slice level, i.e., the detection sensitivity is much more uniform across the whole heart volume and higher than for any of the two individual views when used separately, or even when summed. The optimal image multiplication formula should involve more precise modeling of the heart and the surrounding varied tissues, and this will be defined during the future planned research, but even this overly simplified mathematical description shows the main feature and power of the co-registered imaging.
29) Referring to FIG. 1 , geometrical parameters of the approximate formula used in the text. The heart sector with radiation activity A is at depth d below the heart surface measured in the direction of camera 20 . Heart thickness at the particular cross-section level is T. The gamma rays reaching the two detectors from the selected heart sector are approximately contained within the projective tube, due to the use of parallel-hole collimators.
30) The core of the present disclosure is the use of two co-registered (pixel-by-pixel) series of dynamic images obtained from two opposed (set at 180 degree relative to each other) gamma imaging heads, to maximize uniformity of detection sensitivity of blood flow in and around the heart over the whole heart volume, with minimization of radiation absorption effects.
31) A normalization/image fusion technique is implemented pixel-by-corresponding pixel to increase signal for any cardiac region viewed in two views/images obtained from two opposed detector head positions for the same time bin. Typically 10 msec time bins will are used for fast dynamic cardiac imaging, but other time bins are possible, up to about 1 sec. The two detector head positions are geometrically aligned to better than 1 mm to achieve the required precise and unique one-to-one detector pixel correspondence.
32) An example of a camera head construction according to the present invention is shown in FIG. 2 . The detector head sensor components include an array of 16 (4×4) Burle 85001-501 flat PSPMTs (Position Sensitive PhotoMultiplier Tubes) 30 coupled through optical spreader window 32 to a scintillation array 34 encapsulated behind a window 36 . Reflective strips 38 are placed in the dead regions between the PSPMTs to improve scintillation light collection from the approximately 2 cm wide dead regions between the PSPMTs. The shielding and the collimator are not shown in this figure.
33) The preferred embodiment of the compact dual opposed head cardiac imager system 20 shown in FIG. 2 is based on an array of 16 Burle 85001-501 flat PSPMTs 30 arranged in a 4×4 array and coupled to a 0.6-1.2 cm thick Saint Gobain Crystals and Detectors NaI(T1) scintillator pixel array 34 having 5 mm-10 mm pixel size. This configuration is optimized for 140 keV energy photons from Tc-99m. Other PSPMT types such as Burle 85011-501, and Hamamatsu H8500 and H9500 can also be used in the gamma detector heads.
34) FIG. 3 shows an example of a dual-head imaging system 20 placed on both sides of a patient torso 26 . In FIG. 3 , the mechanically co-registered opposed dual-head single gamma imager 20 is placed at 30 deg RAO relative to the patient's heart 40 . The second detector head 22 is placed behind the torso of a sitting or laying down patient. Detector head shielding, collimators, and patient chair or bed are not shown in this figure. The distance between the detector heads 21 and 22 can be adjusted to accommodate different situations (chair or bed) with different sized patients.
35) The support detector 22 head placed behind the back is more sensitive to the gamma rays emitted from blood flowing in the back part of the heart 40 , which is much less visible to the front detector 21 . The combined pixel-by-pixel image from both detectors 21 and 22 presents much more uniform sensitivity to the dynamics of blood flow throughout the heart 40 , and more specifically, at the back side of the heart.
36) Each detector head images a heart by detecting emitted gamma rays. The gamma rays are emitted from a radioactive bolus such as Tc-99m, which is the most popular label used in nuclear medicine and is Man energy range (140 keV) that can be measured by the dual-headed imager system. Each imager head will operate in the gamma energy range of 140-159 keV with rate capability approaching 500 kHz. The high rate capability is the result of the design of the instrument including the capability of operating in parallel digital data flow mode for transferring digitized information from the digital imaging camera detector. This high rate performance will be especially well adapted to the so-called “first-pass” heart imaging procedure. Prior art gamma cameras in medical practice have intrinsic rate capability limited to less than about 100 kHz due in part to their slow front-end electronics and data acquisition systems.
37) As shown in FIG. 4 , a second embodiment of the absorption-correcting first-pass cardiac system 41 of the present invention includes two pairs of co-registered gamma detector heads 42 and 44 . The use of two pairs of compact co-registered gamma imagers provides a stereotactic view of the heart and region around the heart 40 . The angles and positions of the detectors 42 and 44 relative to the patient's body and the relative angles between the two pairs are flexible and adjustable within the mechanical limitations dictated by the size of the detector heads and the associated mounting gear. The simultaneous dynamic recording of two stereotactic views of the heart will provide depths information to disentangle contributions from overlapping sections of the heart. Based on these complementary views, the specialized adjunct software will de-convolve these contributions based on a dynamic model of the propagation of the injection bolus in the heart chambers and in the coronary system. This will result in the most powerful first-pass cardiac imaging system to date, free of the two key limitations of the previous single gamma imaging implementations, namely the gamma absorption effect, and the feature overlap in one view of the heart.
38) A possible third embodiment is to use the original one set of two co-registered cameras but to split the injection procedure into two injections separated by a short time of the order of about 60 seconds, with heart viewed from two different stereotactic directions. In this tightly executed timed procedure, after about 30 sec of data collection for the first view of the heart, the detector heads will be swiftly repositioned to the second view position and the new injection will be executed with a second imaging run of about 30 sec. The second injection will be adding the activity from a radioactive bolus to the activity present in the patient's body from the previous injection, but with proper modeling of the dynamic phenomena in the heart region and subsequent removal of background levels, more information about dynamics of the blood flow will be obtained than if limited to the one obtained from the first injection only. This approach enables the use of a more economical system in the highly enhanced first pass cardiac procedure. This rarely used imaging modality will be more practical to put into use as a result of the highly improved first-pass imaging procedure provided by the present invention. This allows exploitation of the full diagnostic potential for First-Pass RNA by providing crucial information about the dynamic function of the patient's heart and coronary system in a very short period of time, such as a few minutes. This powerful and unique benefit from First-Pass RNA has critical importance in emergency situations for triage and detection of potential myocardial infarctions and can be an economical, safe and reliable diagnostic for coronary artery disease, valve disease, and cardiac function used in the cardiology clinic or hospital outpatient setting.
39) The successful implementation of the proposed high performance mobile dual-head imager concept with resolution of 6-10 mm FWHM (Full Width at Half Maximum) adequate for heart imaging can provide a very useful diagnostic heart imaging tool to cardiac professionals in the ER/ICU environment.
Experimental Results:
40) The experimental system used to demonstrate the cardiac planar imager was composed of two prototype compact gamma imagers with a 20×15 cm active field of view each. Two identical high-resolution parallel-hole lead collimators were used on both camera heads. The clinical cardiac imaging situation was approximated by a torso phantom and a heart phantom. The cameras were mounted on the mammography gantry and placed at a 24 cm distance to provide space for the torso phantom.
41) An alignment procedure was performed in order to improve the resolution and significantly decrease the background radiation outside the small features of interest. To align the cameras mechanically and in software before the torso phantom studies, a special square capillary phantom is used with four capillaries filled with Tc99m activity and aligned to form a 10 cm square.
42) The four-capillary phantom was mounted on a plastic support plate in the center plane between the detectors. The capillary phantom was filled with low level activity to demonstrate also the background rejection feature of the dual-head system. The individual normalized energy spectra obtained during the capillary run are depicted in FIG. 5 and show high level of outside background (natural radioactivity, cosmic radiation, etc), in addition to the 141 keV photopeaks from Tc99m present in the capillaries.
43) With reference to FIG. 5 , the normalized energy spectra (Detector 1 —left, and Detector 2 —right) obtained during the capillary alignment run show high level of background, in addition to the (shaded) 141 keV photopeak regions used in image formation for the two imagers, respectively. A rather broad energy region of 128-193 keV was used in these studies to allow for even more background in the images.
44) FIG. 6 : The phantom images from the detector 1 , detector 2 , and the combined (after mechanical and software alignment) are shown in FIG. 6 . Images obtained from the two detectors (left-detector 1 , middle-detector 2 ) and the combined image at right. The horizontal lines in the left image demark a Y-strip used in all images to produce X-projective profiles, as explained below. Two features are immediately obvious from the comparison of the images above. First, the ratio of image background (present outside the capillaries) to capillary signal is lower in the combined image. Second, the capillaries are seen narrower in the combined image, which indicated higher spatial resolution than in the individual images.
45) To better demonstrate quantitatively the above effects, 10-channel wide Y-strips were selected in the three of FIG. 6 and their content projected to X-coordinate. The results are shown in FIG. 7 . Y-strip X-coordinate projections are shown from detector 1 (at left), detector 2 (center), and the combined image (at right). These profiles confirm substantial reduction (almost ten-fold) in background level relative to the capillary signal, and improvement in spatial FWHM resolution from about 3.5 pixels (11.2 mm) to about 2.75 pixels (8.8mm) (each image and histogram pixel is 3.2 mm wide). Benefiting from the above spatial resolution improvement using combined images, smaller heart features such as vulnerable plaques can be potentially detected, or higher resolution collimators could be implemented to increase the cardiac imaging system's dynamic sensitivity (higher image counts per each time bin).
46) For experimental phantom cardiac studies, two slightly different experimental setups were used to demonstrate the increase in detection sensitivity of the new proposed dual-imager approach to detect cardiac features such as left coronary artery placed at the back side of the heart, away from the chest wall, with the cardiac imager system configured as shown in FIG. 1 .
47) FIG. 1 shows heart sector at the back region of the heart and away from detector 21 placed in the 30 deg. Right Anterior Oblique heart view position at the patient's chest wall. While the right coronary arteries are close to detector 21 , left coronary arteries are away from this detector and gamma rays emitted from that far region are substantially absorbed in the heart muscle before reaching detector 21 (the absorption factor is over a factor of 2 in 6 cm of muscle tissue). It is the additional back detector 22 that is well positioned to detect the signal from the left arteries.
First Experimental Setup:
48) To simulate detection of the coronary (or other hot spot type) blood flow or uptake activity at the back side of the heart (away from the chest wall and the front detector 1 ) Data Spectrum Corporation's Cardiac Insert™ phantom, available from Data Spectrum Corp., Hillsborough, N.C., was used with cold torso phantom. The SPECT torso phantom is ˜21.5 cm in diameter and 16.5 cm high and was filled with about 6000 cc of radioactively cold water to simulate the absorption and scatter effects of the human torso (minus the bone structures) during the first pass type procedure. A small cylindrically shaped container having a 5.5 cc volume was attached to the cardiac phantom side close to detector 2 . Both the attachment and the inner approximately 100 cc ventricular volume were filled with radioactive Tc99m solution of the same activity level of about 1 μCi/cc. The outer “myocardium” 1 cm thick chamber of the cardiac phantom surrounding the inner ventricular chamber was filled with radioactively cold water. Cylindrical torso container was filled with radioactively cold water to simulate scatter and absorption in the human torso.
Results from the First Setup:
49) With reference to FIG. 8 , it is obvious visually that while the front detector is not seeing well the “coronary” activity behind the “ventricle” region, the back detector, close to the outside attachment, provides a strong evidence of additional activity there, while the combined image provides the strongest and cleanest signal.
50) Referring to FIG. 9 , the contrast values for the longitudinal profile plots in the three images depicted in FIG. 8 are ˜9%, ˜39%, and ˜63% respectively for the front imager (left plot-detector 1 ), back imager (middle plot-detector 2 ) and overlay plot at right. (Contrast id is defined as: CONTRAST=100%*(N R −N B )/N B ), where N R is the signal value at the region of interest and N B is the signal value outside the region of interest—i.e. background.) Note that the relative background level is lowered for the combined image and structure looks “sharper” due to better spatial resolution of the combined system as compared to its two components.
Second Experimental Setup:
51) Progressing towards a more realistic situation with distributed coronary artery activity at the back of the heart, a balloon with 5.5 cc of blood-level radiation activity (the same as in the ventricle) was taped to the left side of the phantom in place of the small container as used in the previous study. A balloon filled with 5.5 cc of the blood-level activity was attached to the left side of the cardiac insert.
Results from the Second Setup:
52) Examples of the results obtained in the first-pass type simulation study with the attached flattened balloon at the outside wall of the cardiac insert phantom are shown in FIGS. 10-12 . FIG. 10 depicts the raw image and longitudinal profile obtained in the first detector (gamma imaging head 21 in FIG. 1 ). There is low evidence of additional structures in the raw image of FIG. 10 . FIG. 11 depicts the raw image and longitudinal profile obtained in the second detector 2 (gamma imaging head 22 in FIG. 1 ) Evidence of an additional signal is indicated in FIG. 11 . FIG. 12 depicts the combined image and longitudinal profile obtained from both detectors. In comparison to the expected higher signal in the second detector (higher hump at the center-right), the combined additional signal is even higher, the profile slopes are sharper, and the background is highly reduced outside the image of the left ventricle.
53) FIG. 13 depicts the combined image and longitudinal profile after normalization of the combined image by the combined flood image. The combined flood image was obtained from multiplication of the co-registered individual flood images. After normalization, the profile shows less statistical fluctuation and provides stronger evidence of the local increase in acquired signal in the region of the balloon.
54) FIG. 14 depicts the same three images after software smoothing, with the image on the left from detector 21 (See FIG. 1 ), the center image from detector 22 , and the right image being the combined image. The significance of FIG. 14 is that detector 1 is practically not showing the signal increase due to the balloon, while there is an indication of such an increase in detector 2 .
55) In summary, the above experimental studies, performed in approximate physical conditions with substitute detectors and phantoms, provided the experimental confirmation of the theoretical concepts described herein for the present invention.
Third Experimental Setup:
56) The same experimental system was used as described in the previous experiments. The purpose of this additional study was to better simulate the realistic conditions during the first-pass cardiac imaging procedure.
57) To simulate better the realistic clinical conditions, an accurately anatomic heart cardiac phantom, available from Radiology Support Services, Long Beach, Calif., was used with a cylindrical container simulating patient's torso. The heart phantom is based on vacuum-formed shells. It was designed using high resolution CT data from a normal patient. It has the left and right ventricular chambers connected at the atrium region to make a single compartment, which can be filled and flushed independently. The volume of the heart chambers is 284 ml, while the volume of the myocardial wall is 238 ml.
58) The SPECT cylindrical torso phantom is approximately 21.5 cm in diameter and 16.5 cm high and was filled with about 6000 cc of radioactively cold water to simulate the absorption and scatter effects of the human torso (minus the bone structures) during the first pass type imaging procedure.
59) Only the left ventricle of the phantom (approximately 100 cc) was filled with Tc99m activity at a 0.3 μCi/cc level, while the rest of the phantom and the torso were filled with “cold” water. Three 2.7 mm inner diameter, 4 inches long tubes made of pieces of intravenous tube and about 0.6 cc in volume each were used to simulate the coronary arteries. They were filled each with approximately 2 μCi of activity at a ratio of approximately 10:1 to the left ventricle activity (3 μCi/cc). This choice or activities was intended to simulate the dynamic situation at the moment of the radioactive bolus being ejected with the blood flow from the left ventricular chamber to the aorta and the coronary arteries. One tube was attached outside the right ventricle region facing the right gamma camera placed at the front of the heart phantom, while two tubes were attached on the left ventricle side and close to the back detector placed behind the “patient”.
60) The right detector is placed at about 30 deg. RAO (Right Anterior Oblique) position relative to the heart. The back detector is closer to the left ventricle and the two coronary arteries placed there.
61) Imaging was performed for about 25 minutes at this very low activity level. The low activity level was selected for convenience of safe working with low level activities and to satisfy low detector rate capability of this breast imaging demo system not designed for high rate operation required for cardiac imaging.
62) Smoothed resulting images, using NIH Image software, are depicted in FIGS. 15-17 . The smoothed images from the front detector, as shown in FIG. 15 , show some evidence of the right coronary in center (indicated by arrow) and no left coronaries visible. The smoothed images from the back detector, as shown in FIG. 16 , show clear evidence of left coronaries and slight indication of the right coronary in the center. The combined image, shown in FIG. 16 , shows all three coronaries as highlighted by the arrows in the figure.
63) In realistic conditions with a beating heart and coronary arteries moving with the heart muscle, detection of the signals from individual coronary arteries will be highly enhanced by using the cardiac imaging system of the present invention having dual gamma imaging heads co-registered with one another.
65) The above experimental results demonstrate again and reconfirm that addition of a second back gamma camera, co-registered with the first gamma camera, greatly improves detection of the signal from the left coronary system, therefore improving diagnostic power beyond that available from conventional nuclear medicine cardiac systems.
66) Although the description above contains many specific descriptions, materials, and dimensions, these should not be construed as limiting the scope of the invention but as merely providing illustrations of some of the presently preferred embodiments of this invention. Thus the scope of the invention should be determined by the appended claims and their legal equivalents, rather than by the examples given.
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A cardiac imaging system employing dual gamma imaging heads co-registered with one another to provide two dynamic simultaneous views of the heart sector of a patient torso. A first gamma imaging head is positioned in a first orientation with respect to the heart sector and a second gamma imaging head is positioned in a second orientation with respect to the heart sector. An adjustment arrangement is capable of adjusting the distance between the separate imaging heads and the angle between the heads. With the angle between the imaging heads set to 180 degrees and operating in a range of 140-159 keV and at a rate of up to 500 k Hz, the imaging heads are co-registered to produce simultaneous dynamic recording of two stereotactic views of the heart. The use of co-registered imaging heads maximizes the uniformity of detection sensitivity of blood flow in and around the heart over the whole heart volume and minimizes radiation absorption effects. A normalization/image fusion technique is implemented pixel-by-corresponding pixel to increase signal for any cardiac region viewed in two images obtained from the two opposed detector heads for the same time bin. The imaging system is capable of producing enhanced first pass studies, bloodpool studies including planar, gated and non-gated EKG studies, planar EKG perfusion studies, and planar hot spot imaging.
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FIELD OF THE INVENTION
[0001] The present invention relates to a beverage container. More particularly this invention concerns such a container for a pressurized beverage, for instance soda, sparkling wine, or beer and having a fitting for filling or emptying the beverage and for venting it in case of a dangerous overpressure.
BACKGROUND OF THE INVENTION
[0002] A container having a safety vent or a predetermined burst point is known from U.S. Pat. No. 6,241,116. This metal container has a hollow body accommodating the filling or the beverage and composed of an essentially cylindrical jacket and two outwardly curved end walls. At least one of the end walls has a bulge that preferably protrudes as a so-called cup-shaped bottom from the curved end wall, wherein a container connecting pipe is provided in the cup-shaped wall. At least one of the end walls is provided with a notch embodied on its outside as an intended release point that fulfills the function of an overpressure protection or an overload protection.
[0003] The overpressure protection that is known in various variants from DE 40 41 636 is intended to prevent internal pressure in the container from rising up to a very high value and burst the container in the event of incorrect treatment of the container as well as with incorrect operation or loss of function of pressure-reducing organs. Instead, at a defined pressure below the maximum bursting pressure of the container, the produced overpressure is dissipated in a safe manner by the automatic opening of the safety vent or safety release point in the container wall.
[0004] A container described in US 2011/0280502 has an internal bladder formed at its top or head end with a sleeve-like connector that can be connected to a valve or safety fitting for filling the liquid and having respective closeable passages for compressed gas and for the beverage. The containers or bladders, in particular made from PET, are used in beverage-dispensing apparatuses for CO 2 compressed gas-operated dispensing of beverages cooled to drinking temperature. The beverage can be removed or the container/the bladder can be filled via a tap head that can be placed on the fitting that has a beverage valve and a gas valve, mounted on the container or the bladder at the top, and is attached via an adapter ring connecting the connector of the container or of the bladder with a detent groove of the fitting from outside, or to a connection piece that can be mounted thereon. The beverage is then forced to the beverage outlet via a riser tube projecting from above down into container.
[0005] A beverage-dispensing device with a fitting mounted on the top of the liquid container is furthermore known from US 2010/0120897. To attach the fitting, the mouth of the container is formed with a flange is surrounded around by a connecting piece, for example, a metallic clamp ring or a screw-on plastic ring. The riser tube or fitting tube is there embodied as a moveable component of the seal that can be adjusted longitudinally and can be set in a number of different positions.
OBJECTS OF THE INVENTION
[0006] It is therefore an object of the present invention to provide an improved container for a pressurized beverage.
[0007] Another object is the provision of such an improved container for a pressurized beverage that overcomes the above-given disadvantages, in particular in which a safety vent with better functionality can be provided in a simpler manner.
SUMMARY OF THE INVENTION
[0008] These objects are attained with a fitting used with a container holding a pressurized beverage and adapted for connection to a filling or dispensing device. The fitting according to the invention has an annular and outwardly projecting collar formed unitarily with the fitting and forming a passage opening into the container and a flexible burst membrane in the fitting and blocking the passage.
[0009] A safety vent is thus provided that is not subject to any limitations during production, in that it is made in one piece with the fitting present anyway for filling with a beverage in a brewery or for tapping by the consumer. In contrast, the predetermined release points provided by notches in the container with a bladder of PET or plastic optionally inserted therein must be produced either by machining, such as by milling or by laser processing, or by embossing a closed or partially interrupted notch that is usually circular. However, according to the invention the burst membrane, which can be composed of different frangible or flexible materials such as ceramic or metal or a film of plastic, needs only to be inserted into the collar and to be attached covering the wall hole, e.g., by adhesion. It is easy to provide the manufacturer with an assortment of membranes set to rupture or burst at different pressures, depending on what is being packaged.
[0010] According to a preferred embodiment of the invention, a perforation element has a cylindrical forming head fitted into the collar from outside or fitted thereon. This head has a point facing toward the burst membrane and for manual unloading of the safety vent has a tab extending angularly of the center axis of the fitting from the forming head and, when lifted away from the fitting, moves the point into the burst membrane. The thus bidirectional safety vent of the fitting, e.g. a basket fitting, a flat fitting or a triangular fitting, according to the invention provides an additional function, namely, in addition to the overpressure protection or overload protection, a targeted pressure relief to be triggered manually from outside, such as in particular to ensure a completely depressurized container for the disposal thereof. By pulling the tab, the otherwise stationary point moves in the direction toward the container or the burst membrane thereof and pierces or destroys it. By means of the forming head plunging into the collar, which forming head can be held in or on the collar by clamping, welding or adhesion, the burst membrane can also be inserted loosely into the collar, optionally with interposition of a seal ring.
[0011] For easier actuation and introduction of the targeted manual pressure relief, a release lug that projects outward is molded on the tab. The tab hugging the wall of the fitting over its limited length can thus be easily gripped and pulled away by the release lug simultaneously used for pressure relief.
[0012] According to a further proposal of the invention, the tab is formed with a film hinge extending across its width in the region between the release lug and the molded head. The original condition of the safety vent can be thus be monitored, so that it forms a tamper indicator. If it has already been activated manually for pressure relief, this is immediately discernible due to the film hinge that is then broken.
BRIEF DESCRIPTION OF THE DRAWING
[0013] The above and other objects, features, and advantages will become more readily apparent from the following description, reference being made to the accompanying drawing in which:
[0014] FIG. 1 is an axial section through an upper region of a container according to the invention;
[0015] FIG. 2 is a large-scale exploded perspective view of a detail of the closure of the container;
[0016] FIG. 3 is a large-scale perspective view in axial section through the closure; and
[0017] FIG. 4 is a perspective view from above of the closure.
DETAILED DESCRIPTION
[0018] As seen in the drawing a container 1 for holding or pressurized dispensing of beverages such as beer, soft drinks and sparkling wine has an outer sheet-steel jacket 2 (only shown partially) and a bladder 3 of thermoplastic film, in particular PET, therein. The bladder 3 holds a body of the liquid beverage being stored and dispensed by the container 1 as well as a volume of compressed gas, typically carbon dioxide, above it.
[0019] A fitting 5 generally centered on an axis A of the container 1 is secured to the mouth of the container 1 via an internally threaded adapter ring 4 and has a riser tube 6 projecting axially down into the bladder 3 and through which the liquid can rise from the body B. A connector for filling with a beverage in a brewery, for example, or a tap head for tapping by the consumer can be attached to the axial upper end of the fitting 5 as is known per se. The riser tube 6 forms a passage for the liquid to rise from body B to the fitting 5 and another passage 9 opens into the volume V of compressed CO 2 and can be supplied with more compressed gas if necessary by a dispensing apparatus connected to the fitting 5 .
[0020] As can be seen in FIGS. 2 through 4 , the fitting 5 is provided with a safety vent 7 . It comprises an annular radially outwardly projecting cylindrical collar 8 molded in one piece with the fitting 5 and forming a radially extending or open passage or hole 10 opening radially inwardly into the gas flow passage 9 of the fitting ( FIG. 3 ). A flexible, semielastic, or otherwise frangible burst membrane 12 is fitted into the collar 8 with the interposition of a seal ring 11 so that it closes or blocks the hole 10 and is stretched and bursts if an internal overpressure occurs. It is typically constructed to burst at a maximum pressure of 25 bar, lower with a thin-walled container.
[0021] The burst membrane 12 that may for example be adhesively attached is held in the collar 8 by a perforation element 13 that has a cylindrically tubular head 14 press fitted into the collar 8 and fixed there by an unillustrated ring clamp, for example. The head 14 is formed with a point 15 directed radially toward but spaced radially outward from the burst membrane 12 ( FIG. 3 ), and serving to ensure activation or opening of the safety vent 7 in that the bursting element 12 engages outward against it in the case of overpressure and is then torn or punctured at the latest when it strikes the point 15 .
[0022] The perforation element 13 is furthermore provided with a circularly arcuate tab 16 that in the installed situation shown in FIG. 4 hugs the outer surface of the fitting 5 along its full length. The safety vent 7 is given an additional function by the perforation element 13 , namely a targeted manual pressure relief by lifting or pulling away the tab 16 from the fitting 5 so that the point 15 is moved in the direction of the burst membrane 12 , penetrating and destroying it. For easy handling when pulling off or pulling away the tab 16 it is provided with a release lug 17 .
[0023] The tab 16 is formed between the release lug 17 and the molded head 14 with film hinge 18 running across its entire width 16 , i.e. from the top downward. This film hinge 18 provides a visual indication of the original condition of the safety vent 7 , in that it is immediately discernible by simple inspection whether the film hinge 18 has already been broken and thus a manual pressure relief has already been carried out.
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A fitting used with a container holding a pressurized beverage and adapted for connection to a filling or dispensing device has an annular and outwardly projecting collar formed unitarily with the fitting and forming a passage opening into the container and a flexible burst membrane in the fitting and blocking the passage.
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RELATED APPLICATION
[0001] The present application claims priority to U.S. Provisional Application 61/766,080, filed Feb. 18, 2013, the entire contents of which are hereby incorporated.
BACKGROUND
[0002] The present invention relates to an air and lubricant monitoring system for mining equipment, such as shovels.
SUMMARY
[0003] Finely-tuned air and lubricant systems provide optimal productivity and operation of mining equipment, such as a shovel. Accordingly, embodiments of the present invention monitor air pressure using either a pressure transducer or pressure switch. If the air pressure in the system drops below original equipment manufacturer (“OEM”) specs for more than a predetermined period of time (e.g., approximately two seconds) during operation, a controller included in the shovel can initiate a delayed shutdown, which stops the shovel in approximately 30 seconds. Appropriate setting of the air pressure at the compressors and the behavior of the air system in combination with the shovel's brakes and lubricant systems help determine key performance indicators (“KPIs”) for the shovel that can be used to manage the operation of the shovel.
[0004] In particular, specific trend behaviors of the air pressure system, brakes release indicators, brakes solenoids, brakes pressures, and lubricant systems can be recorded and analyzed. Oscillations or sizable drops in the air pressure are generally primary indicators of any anomaly in the air system or related components. The outliers are filtered while the machine is either in a shutdown sequence or in an idle mode that is determined by the machine's state digital signal codes. Essentially, the minimum setting is the first check point taken into consideration to begin with and prior to any digging into brakes and lubricant analytics.
[0005] Although observing and analyzing the air pressure system and the related subsystems in approximately real-time provides benefits, automatic predictive failure analysis provides additional advantages. In particular, condition-based equipment models (“CBEMs”) can be used to predict and notify operators of any potential problems or failures. The condition based models look for specific changes in the functionality of the shovel and the related systems that might indicate the potential of a future problem or failure.
[0006] For example, brake set and release times are some of the characteristics the predictive model programs can analyze. For example, correlating anomalies in the air pressure with the delayed brakes release mechanisms on the hoist and crowd motions can help determine if the brakes air supply regulator needs to be adjusted. Historical data analysis indicates that it could take approximately 0.7 seconds to 1.2 seconds from the time an operator initiates a brake release function until the motion is halted. During this time, brakes supply regulator is presumed to be set around 100 PSIs. Although it would be nearly impossible for an analyst to actively monitor the brake system set and release times for slight changes, indicating a potential failure, the predictive models are analyzing this data continuously.
[0007] Similarly, the lubricant system, including the upper and lower open grease systems, are tied to the air system. Leaks in the lubricant system air supply, as well as, insufficient lubricant pressures and functionality can be analyzed and determined. As the time-series data is collected, statistical assessment with the historically-derived control parameters, help detect any deviation each time a dip or spike behavior is logged. For example, improper grease levels have been determined to be secondary indicators of improper functioning of the air and lubricant systems.
[0008] Monitoring the above mentioned KPIs and processing them in approximately real-time can detect out-of-normal settings and indiscernible changes. Advanced and early prognostics supported by proven diagnostics (e.g., based on access to a large amount of data different mechanical settings) further intensify the analytics. All of this functionality helps rule out the obvious, and not so obvious, in a prompt fashion, which reduces unwanted downtime resulting in loss of production.
[0009] Accordingly, one model (an air pressure model) is used to detect dips and spikes in pressure. An alert is generated based on both the amount of deviation from expected pressure level and the frequency of deviations in a timer period. Another model (a lubricant system pressure model) detects a dip in air pressure when lubricant action has activated. An alert is generated if the dip is excessive. Yet another model (a lubricant system cycle time model) determines if dips in air pressure occurring when lubricant action is activated remain for an excessive period of time. A further model (a lubricant system reaction time model) determines an amount of time it takes to reach appropriate pressure levels when lubricant action is activated. An alert is generated if the amount of time is excessive.
[0010] In one embodiment, the invention provides a mining machine including fluid system. The mining machine including a fluid pressure sensor operable to sense a pressure level of a fluid in the fluid system of the mining machine and a controller. The controller operable to analyze the pressure level to detect pressure level deviations; determine at least one selected from the group of when a frequency of the pressure level deviations exceeds a predetermined frequency, and when the fluid pressure level fails to reach a threshold within a predetermined reaction time period; and output an alert in response to the determination.
[0011] In another embodiment the invention provides a method of monitoring a fluid system of a mining machine. The method including sensing a pressure level of a fluid in the fluid system of the mining machine to generate pressure level data; analyzing the pressure level data to detect pressure level deviations; determining at least one selected from the group of when a frequency of the pressure level deviations exceeds a predetermined frequency, and when the fluid pressure level fails to reach a threshold within a predetermined reaction time period; and outputting an alert in response to the determination.
[0012] Other aspects of the invention will become apparent by consideration of the detailed description and accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 illustrates a mining shovel according to an embodiment of the invention.
[0014] FIG. 2 illustrates a control system of the mining shovel of FIG. 1 .
[0015] FIG. 3 illustrates an air system of the mining shovel of FIG. 1 .
[0016] FIG. 4 illustrates a lubricant system of the mining shovel of FIG. 1 .
[0017] FIG. 5 illustrates an air pressure monitoring process or method according to an embodiment of the invention.
[0018] FIG. 6 illustrates a lubricant pressure monitoring process or method according to an embodiment of the invention.
DETAILED DESCRIPTION
[0019] Before any 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 construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein are for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein are meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless specified or limited otherwise, the terms “mounted,” “connected,” “supported,” and “coupled” and variations thereof are used broadly and encompass both direct and indirect mountings, connections, supports, and couplings.
[0020] In addition, it should be understood that embodiments of the invention may include hardware, software, and electronic components or modules that, for purposes of discussion, may be illustrated and described as if the majority of the components were implemented solely in hardware. However, one of ordinary skill in the art, and based on a reading of this detailed description, would recognize that, in at least one embodiment, the electronic based aspects of the invention may be implemented in software (e.g., stored on non-transitory computer-readable medium). As such, it should be noted that a plurality of hardware and software based devices, as well as a plurality of different structural components may be utilized to implement the invention. Furthermore, and as described in subsequent paragraphs, the specific mechanical configurations illustrated in the drawings are intended to exemplify embodiments of the invention and that other alternative mechanical configurations are possible.
[0021] FIG. 1 illustrates a mining shovel 100 , such as an electric mining shovel. The embodiment shown in FIG. 1 illustrates the mining machine as a rope shovel, however, in other embodiments the mining shovel 100 is a different type of mining machine, such as for example, a hybrid mining shovel, a dragline excavator, etc. The mining shovel 100 includes tracks 105 for propelling the rope shovel 100 forward and backward, and for turning the rope shovel 100 (i.e., by varying the speed and/or direction of the left and right tracks relative to each other). The tracks 105 support a base 110 including a cab 115 . The base 110 is able to swing or swivel about a swing axis 125 , for instance, to move from a digging location to a dumping location. Movement of the tracks 105 is not necessary for the swing motion. The rope shovel further includes a dipper shaft 130 supporting a pivotable dipper handle 135 (handle 135 ) and dipper 140 . The dipper 140 includes a door 145 for dumping contents from within the dipper 140 into a dump location, such as a hopper or dump-truck.
[0022] The rope shovel 100 also includes taut suspension cables 150 coupled between the base 110 and dipper shaft 130 for supporting the dipper shaft 130 ; a hoist cable 155 attached to a winch (not shown) within the base 110 for winding the cable 155 to raise and lower the dipper 140 ; and a dipper door cable 160 attached to another winch (not shown) for opening the door 145 of the dipper 140 . In some instances, the rope shovel 100 is a Joy Global Surface Mining® 4100 series shovel produced by Joy Global Inc., although the electric mining shovel 100 can be another type or model of mining equipment.
[0023] When the tracks 105 of the mining shovel 100 are static, the dipper 140 is operable to move based on three control actions, hoist, crowd, and swing. The hoist control raises and lowers the dipper 140 by winding and unwinding hoist cable 155 . The crowd control extends and retracts the position of the handle 135 and dipper 140 . In one embodiment, the handle 135 and dipper 140 are crowded by using a rack and pinion system. In another embodiment, the handle 135 and dipper 140 are crowded using a hydraulic drive system. The swing control swivels the handle 135 relative to the swing axis 125 . Before dumping its contents, the dipper 140 is maneuvered to the appropriate hoist, crowd, and swing positions to 1) ensure the contents do not miss the dump location; 2) the door 145 does not hit the dump location when released; and 3) the dipper 140 is not too high such that the released contents would damage the dump location.
[0024] As shown in FIG. 2 , the mining shovel 100 includes a control system 200 . The control system 200 includes a controller 205 , operator controls 210 , mining shovel controls 215 , sensors 220 , a user-interface 225 , and other input/outputs 230 . The controller 205 includes a processor 235 and memory 240 . The memory 240 stores instructions executable by the processor 235 and various inputs/outputs for, e.g., allowing communication between the controller 205 and the operator or between the controller 205 and sensors 220 . The memory 240 includes, for example, a program storage area and a data storage area. The program storage area and the data storage area can include combinations of different types of memory, such as read-only memory (“ROM”), random access memory (“RAM”) (e.g.,, dynamic RAM [“DRAM”], synchronous DRAM [“SDRAM”], etc.), electrically erasable programmable read-only memory (“EEPROM”), flash memory, a hard disk, an SD cark, or other suitable magnetic, optical, physical, or electronic memory devices. The processor 235 is connected to the memory 240 and executes software instructions that are capable of being stored in the memory 240 . Software included in the implementation of the mining shovel 100 can be stored in the memory 240 of the controller 205 . The software includes, for example, firmware, one or more applications, program data, filters, rules, one or more program modules, and other executable instructions. The controller 205 is configured to retrieve from memory 240 and execute (with the processor 235 ), among other things, instructions related to the control processes and methods described herein. In some instances, the processor 235 includes one or more of a microprocessor, digital signal processor (DSP), field programmable gate array (FPGA), application specific integrated circuit (ASIC), or the like. In some embodiments, the controller 205 also includes one or more input/output interfaces for interfacing with the operator controls 210 , the mining shovel controls 215 , the sensors 220 , the user-interface 225 , and the other input/outputs 230 .
[0025] The controller 205 receives input from the operator controls 210 . The operator controls 210 include a propel control 242 , a crowd control 245 , a swing control 250 , a hoist control 255 , and a door control 260 . The propel control 242 , crowd control 245 , swing control 250 , hoist control 255 , and door control 260 include, for instance, operator controlled input devices such as joysticks, levers, foot pedals, and other actuators. The operator controls 210 receive operator input via the input devices and output digital motion commands to the controller 205 . The motion commands include, for example, left track forward, left track reverse, right track forward, right track reverse, hoist up, hoist down, crowd extend, crowd retract, swing clockwise, swing counterclockwise, and dipper door release.
[0026] Upon receiving a motion command, the controller 205 generally controls mining shovel controls 215 as commanded by the operator. The mining shovel controls 215 include one or more propel motors 262 , one or more crowd motors 265 , one or more swing motors 270 , and one or more hoist motors 275 . The mining shovel controls 215 further include one or more propel brakes 263 , one or more crowd brakes 266 , one or more swing brakes 271 , and one or more hoist brakes 276 , which are used to decelerate the respective movements of the mining shovel 100 . In some embodiments, the brakes are electrically controlled brakes (e.g., solenoid brakes). In embodiments where the brakes are solenoid brakes, a spring engages the brake when the solenoid is powered off, and the brake is disengaged, or released, when the solenoid is powered on. In other embodiments, the brakes are air brakes (e.g., compressed air brakes). In embodiments where the brakes are air brakes, compressed air is used to apply pressure to a brake pad. In other embodiments, the brakes include one or more solenoid brakes and one or more air brakes. For instance, if the operator indicates via swing control 250 to rotate the handle 135 counterclockwise, the controller 205 will generally control the swing motor 270 to rotate the handle 135 counterclockwise. Once the operator indicates via swing control 250 to decelerate the handle 135 , the controller 205 will generally control the swing brake 271 to decelerate the handle 135 . However, in some embodiments, the controller 205 is configured to limit the operator motion commands and generate motion commands independent of the operator input.
[0027] The controller 205 is also in communication with the sensors 220 to monitor the location and status of the dipper 140 . For example, the controller 205 is in communication with one or more propel sensors 278 , one or more crowd sensors 280 , one or more swing sensors 285 , and one or more hoist sensors 290 . The propel sensors 278 indicate to the controller 205 data (e.g., position, speed, directions, etc.) concerning the tracks 105 . The crowd sensors 280 indicate to the controller 205 the level of extension or retraction of the dipper 140 . The swing sensors 285 indicate to the controller 205 the swing angle of the handle 135 . The hoist sensors 290 indicate to the controller 205 the height of the dipper 140 based on the hoist cable 155 position. In other embodiments there are door latch sensors which, among other things, indicate whether the dipper door 145 is open or closed and measure the weight of a load contained in the dipper 140 .
[0028] The mining shovel 100 further includes one or more fluid systems used to control, or maintain, machine health or functionality. For example, an air system 300 ( FIG. 3 ) supplies compressed air to various areas or components of the mining shovel 100 . Another example of a fluid system is a lubricant system 400 ( FIG. 4 ), which supplies lubricant to various areas or components of the mining shovel 100 . In some embodiments, the fluid systems pressurize fluid and supply the pressurized fluid to various components of the mining shovel 100 . In other embodiments, the fluid system may include an air, oil, or water based cooling or hydraulic control system.
[0029] As shown in FIG. 3 , the controller 205 is further in communication with an air system 300 (e.g., as one of the other input/outputs 230 ). The air system 300 supplies filtered, dried, and lubricated compressed air, as required, to all the air operated components of the mining shovel 100 (e.g., operator cab seat, air horns, air stair, lubricant pump air motors, lubricant system air sprayers, air brakes, air driven cable reel, a filtration system, etc.).
[0030] The air system 300 includes a compressor 305 , an air dryer 310 , an air receiver 315 , one or more air valves 320 , a lubricator 325 , an air manifold 330 , one or more air regulators 335 , and a swivel 340 . The variety of elements of the air system 300 are connected via a plurality of air lines. For example, in operation, the compressed air flows through the air system 300 to the various components via the air lines. The air lines and the direction of the flow therethrough are represented by the arrows connecting the plurality of elements of the air system 300 in FIG. 3 . It should be understood that, in some embodiments, the air system 300 includes more or less elements.
[0031] The compressor 305 is an air compressor used to supply air to the air system 300 . In some embodiments, the compressor 305 is a single compressor system. In other embodiments, the compressor 305 is a dual compressor system. The air dryer 310 removes moisture from the air supplied by the compressor 305 to prevent contamination within the air system 300 . The air receiver 315 is a pressure vessel, or tank, used to store the air supplied by the compressor 305 .
[0032] The one or more air valves 320 can include a variety of air valves, such as diaphragm valves, flow control valves, isolator valves, pilot valves, shutoff valves, or solenoid valves. Diaphragm valves contain a diaphragm, or membrane, that opens/closes the valve. Flow control valves are used to regulate the flow or pressure of air within the air system 300 . Isolator valves are used to separate various components from the rest of the air system 300 , in the case of failure or when maintenance is required on a component. Pilot valves allow high pressure or high flow systems to be controlled at a lower pressure or low flow. The shutoff valve is a valve that controls the on/off supply to the air system 300 . In some embodiments, the mining shovel 100 includes more or less valves.
[0033] The lubricator 325 is used to add lubricant to the air, which is necessary for the moving parts of the various air valves and cylinders in the air system 300 . The air manifold 330 branches the air from the air receiver 315 to various components of the mining shovel 100 . The air regulators 335 are used to lower the air pressure from the air receiver 315 before the air is sent downstream to the various components. The swivel 340 is a mechanical joint that allows the upper portion of the mining shovel 100 to rotate about the lower portion of the mining shovel 100 without damaging various air hoses as well as electrical cabling running between the lower portion and the upper portion.
[0034] In operation, the compressor 305 compresses and pressurizes air into the air receiver 315 . As the air is supplied to the air receiver 315 , the air dryer 310 removes moisture from the air. The dry air is then supplied through the one or more valves 320 . In some embodiments, there are other valves 320 placed in various positions of the air system 300 . The dry air is then supplied through the lubricator 325 , which adds lubricant to the air. The air is then branched out to the various components by the air manifold 330 . If a component requires a lower air pressure, the air is sent through an air regulator 335 before reaching the component. If a component is located in the upper portion of the mining shovel 100 , the air is passed through the swivel 340 . If a component is located in the lower portion of the mining shovel 100 , the air is not passed through the swivel 340 . It should be understood that, in some embodiments, the various components of the air system 300 can be arranged in various configurations, and thus perform functionality in a different order that as noted above. For example, FIG. 3 illustrates air being transported to a component, a component through a regulator 335 , a component through a regulator 335 and the swivel 340 , and a component through the swivel 340 .
[0035] The air system 300 further includes one or more air sensors 350 placed at various positions within the air system 300 . In some embodiments, the air sensors 350 are transducers, which measure pressure levels and convert the pressure levels to electrical signals. For example, an air sensor 350 measures the air pressure of the air system 300 . Although shown in FIG. 3 as being located between the air receiver 315 and air valves 320 , in some embodiments, there are multiple air sensors 350 placed throughout the air system 300 .
[0036] In some embodiments, the air sensors 350 are electrically connected to the controller 205 (e.g., as one of the other input/outputs 230 ). The controller 205 receives the electrical signal from the air sensors 350 . In some embodiments, the controller 205 detects dips and spikes in the sensed air pressure of the air system 300 (e.g., using one or more condition-based equipment models (“CBEMs”) noted above). The controller 205 determines if there is an issue, or a fault, with the sensed air pressure. If the controller 205 determines that there is an issue with the sensed air pressure, such as a current failure, or a possible future failure, the controller 205 indicates the issue to the operator via the user-interface 225 .
[0037] In some embodiments, the controller 205 is further connected to a server 360 via a network (e.g., a local area network, a wide area network, a wireless network, the Internet, etc. or combinations thereof). The controller 205 outputs the sensed air pressure to the server 360 . The server 360 detects dips and spikes in the sensed air pressure (e.g., using one or more CBEM) to determine if there is an issue. If there is an issue, the server 360 indicates the issue to the operator. In some embodiments the issue is indicated to the operator via the user-interface 225 . In other embodiments, the server 360 indicates an issue to the operator via remote messaging (e.g., electronic mail). In other embodiments, the server 360 indicates an issue to a remote user-interface. In some embodiments, the issue is indicated to the operator via a variety of methods discussed above.
[0038] As an example, in some embodiments, the main air pressure of the air system 300 is detected via the air sensor 350 . In such an embodiment, the controller 205 detects dips and spikes in the main air pressure of the air system 300 . The controller 205 determines if there is an issue by calculating the deviation of the sensed air pressure from a first predetermined air pressure threshold (e.g., the OEM specs, approximately 110 psi for AC shovels, approximately 100 psi for DC shovels, etc.) along with the frequency of deviations in a predetermined air pressure time period. For example, the main air pressure is sensed every two seconds, if the sensed air pressure is below the first predetermined air pressure threshold over two consecutive readings an issue is detected. As another example, the main air pressure is sensed every two seconds, if the sensed air pressure falls below the first predetermined air pressure threshold a predetermined amount of times in a predetermined time period, an issue is detected. If the controller 205 determines that there is an issue with the main air pressure, the controller 205 outputs an indication, or an alert.
[0039] In some embodiments, the controller 205 determines if there is an issue, or fault, based on a plurality of factors. The factors include, but are not limited to: air system pressure, air system cycle time, and air system reaction time. The controller 205 may determine there is an issue if the sensed air pressure of the air system 300 goes above or below the first predetermined air pressure threshold. The controller 205 may further determine there is an issue if the air pressure of the air system 300 goes above or below a second predetermined air pressure threshold for a predetermined air pressure time period. The controller 205 may further determine there is an issue if, at the beginning of a lubricant cycle, the air pressure does not reach a third predetermined air pressure threshold within a predetermined air pressure reaction time period.
[0040] As shown in FIG. 4 , the controller 205 is further in communication with a lubricant system 400 . In some embodiments, the controller 205 is electrically connected to the lubricant system 400 via the other input/output 230 . The lubricant system 400 supplies lubricating grease (e.g., lubricant, etc.) to various components of the mining shovel 100 (e.g., boom point sheave, fleeting sheave, shipper shaft bushings, saddle block bushings, center gudgeon bushings and washers, swing shaft bearings, hoist drum sidestand bearings, boom foot pins, front and rear idler bushings, lower roller bushings, final drive shaft bearings and washers, handle rack and pinion, saddle block wear plates, boom wear plates, roller circle, ring gear, etc.). The lubricant flows through the lubricant system 400 to the various components of the mining shovel 100 via a plurality of grease, or lubricant lines. The lubricant lines and the direction of the flow therethrough are represented by the arrows connecting the plurality of elements of the lubricant system 400 in FIG. 4 .
[0041] The lubricant system 400 includes one or more grease tanks 405 , one or more lubricant pumps 410 , one or more lubricant valves 415 , and the swivel 340 . In the embodiment shown in FIG. 4 , the lubricant system 400 provides lubricant to an upper grease system 430 and a lower grease system 435 . The upper grease system 430 includes the components of the mining shovel 100 that are located in the upper portion of the mining shovel 100 . The lower grease system 435 includes components of the mining shovel 100 that are located in the lower portion of the mining shovel 100 . In some embodiments, the lubricant system 400 includes more or less components.
[0042] The grease tank 405 is a vessel, or tank, for storing the lubricant of the lubricant system 400 . The lubricant pump 410 is a pump for moving the lubricant from the grease tank 405 through the lubricant system 400 . The one or more lubricant valves 415 include a variety of lubricant valves, such as, flow control valves, solenoid valves, vent valves, and zone control valves. The flow control valves are used to regulate the flow or pressure of the lubricant. The solenoid valves are valves that are controlled by electrical signals. The vent valves are solenoid valves that allow pressure in the lubrication zones to exhaust back to the grease tank 405 . The zone control valves are solenoid valves that allow lubricant to flow to specific areas of the mining shovel 100 . In some embodiments, the mining shovel includes four zones: the four zones including the upper grease zone, the lower grease zone, the upper open gear zone, and the lower open gear zone.
[0043] In some embodiments, each zone is lubricated according to a lubrication cycle. The lubrication cycle for each zone is set to run automatically as the timer for each cycle reaches its set point and additional prerequisites are met based on logic of the control system 200 . The time between each cycle can be set according to a predetermined cycle time (e.g., one minute, three minutes, five minutes, ten minutes, fifteen minutes, thirty minutes, etc.). In some embodiments, the predetermined cycle time varies from zone to zone.
[0044] In operation, when a lubricant cycle begins, lubricant is pumped from the grease tank 405 by the lubricant pump 410 . Various lubricant valves 415 are opened, for example but not limited to, by an electrical signal from the controller 200 . In some embodiments, the lubricant valve 415 is one of the zone control valves, which open in order to allow lubricant to flow to the corresponding zone. In such an embodiment, the other zone control valves are normally closed and remain closed. The lubricant pump 410 then pumps the lubricant to the corresponding zone for the predetermined cycle time. The lubricant is then provided to the various components of the mining shovel 100 in the corresponding zone of upper grease system 430 or the lower grease system 435 . In some embodiments, compressed air from the air system 300 is pushed through the opened lubricant valve 415 prior to lubricant being pumped through the corresponding opened lubricant valve 415 . In some embodiments, after lubricant is provided to the various components, the lubricant is purged from the lubricant system 400 via compressed air from the air system 300 . Excess lubricant from the various components flows through a vent valve back to the grease tank 405 . A similar lubricant cycle for the remaining zones is then performed.
[0045] The lubricant system 400 further includes lubricant sensors 450 placed at various positions within the lubricant system 400 . In some embodiments, the lubricant sensors 450 are transducers that measure pressure levels and convert the pressure levels to electrical signals. In some embodiments, the lubricant sensors 450 are ultrasonic transducers, which are used to measure distances. In some embodiments, lubricant sensor 450 measures a lubricant pressure of the lubricant system 400 . Although shown in FIG. 4 as being located between the lubricant pump 410 and lubricant valves 415 , in some embodiments, there are multiple air sensors 450 placed throughout the lubricant system 400 .
[0046] In some embodiments, the lubricant sensors 450 are electrically connected to the controller 205 (e.g., as one of the other input/outputs 230 ). The controller 205 receives the electrical signal from the lubricant sensors 450 . In some embodiments, the controller 205 detects dips and spikes in the sensed lubricant pressure of the lubricant system 400 .
[0047] The controller 205 determines if there is an issue with the sensed lubricant pressure by monitoring the lubricant pressure, the lubricant system cycle time, and the lubricant system reaction time (e.g., using one or more CBEMs). The lubricant pressure is monitored for excessive dips or spikes, which may indicate an issue. The lubricant system cycle time is the period of time of a dip. If the time period of the dip is excessive, there may be an issue. The lubricant system reaction time is the amount of time for the lubricant system 400 to reach appropriate pressure levels. If the time is excessive there may be an issue. If the controller 205 determines that there is an issue with the sensed lubricant pressure, such as a current failure, or a possible future failure, the controller 205 indicates to the operator via the user-interface 225 .
[0048] As noted above, in some embodiments, the controller 205 is further connected to the server 360 . The controller 205 can output the sensed lubricant pressure to the server 360 . The server 360 detects (e.g., using one or more CBEMs) dips and spikes in the sensed lubricant pressure to determine if there is an issue. If there is an issue, the server 360 indicates the issue to the operator. In some embodiments the issue is indicated to the operator via the user-interface 225 . In other embodiments, the server 360 indicates an issue to the operator via remote messaging (e.g., electronic mail). In other embodiments, the server 360 indicates an issue to a remote user-interface. In some embodiments, the issue is indicated to the operator via a variety of methods discussed above.
[0049] As an example, in some embodiments, the lubricant pressure of the lubricant system 400 is detected via one or more lubricant sensors 450 . In some embodiments, the lubricant pressure is not detected until after a predetermined time period (e.g., one minute, two minutes, three minutes, etc.) has surpassed after the start of a lubrication cycle. This allows for the lubricant pressure in the system to reach an upper limit set point (i.e., the OEM specs, approximately 1800 psi to 2400 psi for AC shovels).
[0050] Once the predetermined time period has surpassed, the controller 205 monitors the sensed lubricant pressure of the lubricant system 400 . The controller 205 determines if there is an issue, or fault, based on a plurality of factors. The factors include, but are not limited to: lubricant system pressure, lubricant system cycle time, and lubricant system reaction time. The controller 205 may determine there is an issue if the sensed lubricant pressure of the lubricant system 400 goes above or below a first predetermined lubricant pressure threshold (i.e., lubricant system pressure). The controller 205 may further determine there is an issue if the lubricant pressure of the lubricant system 400 goes above or below a second predetermined lubricant pressure threshold for a predetermined lubricant cycle time period (i.e., lubricant pressure cycle time). The controller 205 may further determine there is an issue if, at the beginning of a lubricant cycle, the lubricant pressure does not reach the upper limit set point, discussed above, within a predetermined reaction time period (i.e., lubricant system reaction time).
[0051] In some embodiments, the controller 200 monitors the various issues at various states of the lubricant cycle. For example, upon starting the cycle, the controller 200 monitors at least the lubricant system reaction time. If the reaction time is unacceptable (i.e., it is determined that there is an issue) the mining shovel 100 shuts down, or the mining shovel 100 finishes the lubricant cycle and then shuts down.
[0052] If the reaction time is acceptable (i.e., it is determined there is not an issue), the controller 200 then monitors at least the lubricant system pressure and lubricant pressure cycle time. If three is an issue, the mining shovel 100 shuts down, or the mining shovel 100 finishes the lubricant cycle and then shuts down. If there is not an issue, the mining shovel 100 continues operation.
[0053] FIG. 5 illustrates an embodiment of an air pressure monitoring process or method 500 . One or more air sensors 350 monitor the air pressure of the air system 300 (step 505 ). The air sensors 350 output the sensed data to the controller 205 (step 510 ). The controller 205 detects dips and spikes in the sensed air pressure (step 515 ). The controller 205 determines if there is an issue with the air pressure (step 520 ). If there is an issue, the controller 205 indicates the issue to the operator. After indicating the issue to the operator, or if there is not an issue, the controller 205 continues to monitor the air pressure of the air system 300 (at step 505 ).
[0054] FIG. 6 illustrates an embodiment of a lubricant pressure monitoring process or method 600 . One or more lubricant sensors 450 monitor the lubricant pressure of the lubricant system 400 (step 605 ). The lubricant sensors 450 output the sensed data to the controller 205 (step 610 ). The controller 205 monitors the lubricant pressure, the lubricant system cycle time, and the lubricant system reaction time (step 615 ). The controller 205 determines if there is an issue with the air pressure (step 620 ). If there is an issue, the controller 205 indicates the issue to the operator. After indicating the issue to the operator, or if there is not an issue, the controller 205 continues to monitor the lubricant pressure of the lubricant system 400 (at step 605 ).
[0055] Thus, the invention provides, among other things, an air and lubricant monitoring system for a mining machine, such as a mining shovel. In particular, embodiments of the invention use CBEMs to predict and notify an operator of potential problems or failures. The condition-based models look for specific changes in the functionality of the shovel and the related systems that might indicate the potential of a future problem or failure. It should be understood that the CBEMs can be executed by the controller 205 included in the shovel 100 or can be executed by the server 360 in communication with the controller 205 over one or more wired or wireless connections. Accordingly, the monitoring and predictive functionality can be provided through the controller 205 , the server 360 , or a combination thereof.
[0056] In some embodiments, upon detection of an issue or fault, the controller 205 outputs an indication, or alert, which shuts down the mining shovel 100 . In some embodiments, if a lubricant cycle is currently happening, the controller 205 waits until a lubricant cycle has completed before shutting down the mining shovel 100 . In some embodiments, if a lubricant cycle has not started and the controller 205 detects an issue, the lubricant cycle will not begin.
[0057] Thus, the invention provides, among other things, a system and method of monitoring an air and lubricant system. Various features and advantages of the invention are set forth in the following claims.
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A method of monitoring a fluid system of a mining machine. The method including sensing a pressure level of a fluid in the fluid system of the mining machine to generate pressure level data; analyzing the pressure level data to detect pressure level deviations; determining at least one selected from the group of when a frequency of the pressure level deviations exceeds a predetermined frequency, and when the fluid pressure level fails to reach a threshold within a predetermined reaction time period; and outputting an alert in response to the determination.
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BACKGROUND
The present invention is directed to methods for making berry juice and more particularly, to methods of making juice from açaí berries.
Açaí berries are harvested from a palm tree (Euterpe oleracea Mart) that grows naturally near the Amazon river and its tributaries. The fruit of açaí berries is composed of a nut comprising about 80% of the berry volume, a layer of sclerid cells on the outer periphery of the nut, a matrix layer of lipids, fibers and other compounds outside the nut and a highly pigmented skin that is rich in anthocyanins. The berries are approximately 12 mm in diameter.
The berries degrade quickly once they are picked due to dehydration, bruising damage, microbiological activity, enzymatic activity and bio-chemical activities related to the high ambient temperatures of their environment which range from about 85° F. to about 102° F.). Degradation reduces the anthocyanin content in the skin of the berries.
The berries are traditionally hot soaked in nearby homes followed by a manual extraction of the outer two layers from the nut over a woven screen. This makes a thick pulp which is consumed locally within one day. Additionally, commercial açaí pulp is prepared using the two processes described below.
In a traditional batch process, Açaí is picked in the jungle and put into baskets called rasas. Rasas are carried at ambient temperature to a canoe or boat. The rasas are loaded into a larger boat and transported to an açaí market or directly to a processing plant. Total transport time at ambient temperature is between 2 and 48 hours.
At the processing plant, the açaí berries are soaked in water, normally at ambient temperature. The water may contain sodium hypochloride at a concentration of 100 ppm for up to 30 minutes. The berries are then soaked in hot water between 30 and 45 degrees Celsius for up to 4 hours. These warm berries are removed from the soak tank and processed in a rotating machine with water that rubs off the skin layer, the lipid layer and grains of lignin that are found between the lipid layer and the nut. This process makes a thick pulp that oxidizes rapidly, ferments quickly and contains a mixture of fat and water soluble fractions. The resulting pulp is measured to have a soluble solids level of less than 4 degrees brix. The pulp is sold fresh or pasteurized and/or frozen.
In a continuous process used today, açaí berries are picked in the jungle and put into rasas. The rasas are carried at ambient temperature to a canoe or boat. The rasas are then loaded into a larger boat and transported to an açaí market or directly to a processing plant. Total transport time at ambient temperature is between 2 and 48 hours.
At the processing plant, the açaí berries are soaked in hot water, normally at 40 to 60 degrees Celsius for 3 to 15 minutes. These warm berries are removed from the soak tank and processed in a rotating machine with water that rubs off the skin layer, the lipid layer and grains of lignin that are found between the lipid layer and the nut. This process also makes a thick pulp that oxidizes rapidly, ferments quickly and separates into fat and water soluble fractions quickly. The pH of this product is approximately 5.8 unless citric acid is added in the process to reduce the pH. The pulp is measured to have a soluble solids level of 3 to 4 degrees brix. The pulp is sold fresh or pasteurized and/or frozen.
There are numerous problems with pulp extracted by the existing processes. The pulp product contains “açaí sand” which is made of sclerid cells of lignin comprising up to 25% of the pulp by volume. These cells are extremely hard and abrasive. The abrasive nature of the cells damages processing equipment and prevents further processing through some homogenizers. The organoleptic impact of these cells has caused unpleasant mouth feel in many beverages blended with pulp containing açaí sand.
Additionally, the pulp product contains up to 50% lipids on a dry-weight basis. These lipids are mainly Omega-6 and Omega-9 fatty acids that are unstable. Rancidity in finished products is normal within 30 days of thawing and rancidity can occur within frozen drums of pulp. Despite extensive processing research, those skilled in the art have been unable remove the açaí sand or the lipids contained in the pulp product once the product has been processed without a significant negative impact on the flavor of the juice.
Additionally, the anthocyanin concentration found in the pulp is diluted by the presence of the water, lipids and the açaí sand. Moreover, the frozen pulp is difficult to thaw prior to use without lipid separation, rancidification or fermentation. Finally, it is very difficult to concentrate the pulp prior to packaging and shipping.
Therefore, a need exists for an improved juice from açaí berries and an improved method of making juice from açaí berries.
SUMMARY
Accordingly, the present invention is directed to a method for making juice from açaí berries that remedies the defects of the prior art. In an embodiment, the method comprises the steps of: chilling the berries to below about 10° C.; extracting a skin from the berries in an extractor with water to obtain a mixture; acidifying the mixture; finishing the mixture; heating the mixture to from about 40° C. to about 60° C.; de-aerating the mixture; passing the mixture through at least one of the group consisting of a high shear mixer, a colloid mill and a hammer mill to yield juice; and pasteurizing the juice.
Prior to chilling, and within about 6 hours of the time the berries are picked, the berries can be loaded into an insulated tanker of water having a temperature of from about 1 to about 5° C. for up to about 48 hours. The water in the tanker can have chlorine dioxide at a concentration of from about 1 to about 35 ppm.
The berries may be chilled by immersing the berries in water having a temperature of from about 1 to about 10° C. for from about 3 to about 10 minutes. Additionally, the mixture can be acidified using lime juice. The finished juice may be packaged. The finished juice may be frozen prior to packaging or following packaging.
The present invention is also directed to a juice made according to the method described herein. The present invention is also directed to a juice made from açaí berries comprising a soluble solids content exceeding three degrees brix. The juice may comprise a lipid content less than about 1% on a dry weight basis. Additionally, the juice may comprise a pH of less than about 5.0, and more preferably, less than about 4.4. Additionally, the juice may be substantially free of açaí sand.
BRIEF DESCRIPTION OF THE DRAWING
A better understanding of the present invention will be had with reference to the accompanying drawing in which:
FIG. 1 is a schematic diagram of a process for making juice from açaí berries according to an embodiment of the present invention.
DETAILED DESCRIPTION
In the method of the present invention, açaí berries are picked and put into baskets that are carried at ambient temperature to a canoe or boat, step 10. At the boat, within about 6 hours of the time the berries were picked, the berries are loaded into an insulated tanker of cold water and moved to a processing plant, step 12. Water temperature in the insulated tanker ranges from about 1 to about 5° C. Preferably, the tankers are transported to the processing plant within about 48 hours of the time that the berries are placed in the water.
Optionally, the water may be treated with chlorine dioxide at a concentration of from about 1 to about 35 ppm, enough citric acid to reduce the water pH below about 4.4, and/or a calcium salt, such as calcium chloride, at a concentration of up to about 1%.
At the plant, the cold berries are removed from the tanker, rinsed and cleaned using a spray wash, step 14. The cleaned berries are then chilled to a temperature below about 10° C. by immersing the berries in water having a temperature of from about 1° C. to about 8° C. for from about 3 to about 10 minutes, step 16.
Once chilled, the berries are subjected to an extraction process in an extractor with small amounts of water that rubs off the skin layer only, thereby resulting in production of a mixture, step 18. The extractor has a drum with a central shaft passing through it. The shaft carries several bars oriented at right angles to the shaft. As the shaft rotates, the bars agitate the berries inside the drum so that the berries rub against each other, the bars and the walls of the drum. This rubbing action roughens the skin of the fruit in preparation for skin removal. The quantity of water used in the extraction process of the present invention is significantly less than the amount required in the traditional extraction processes.
Following the extraction process, the mixture is acidified to a pH that is less 5.0, and preferably less than 4.4, step 20. Numerous known acidulants may be used. Preferably, the acidulant is lime juice. Optionally, the acidified mixture is centrifuged or screened to remove any açaí sand produced by inefficiencies in the extraction equipment.
The mixture is then subjected to finishing, step 22. To accomplish finishing, the berries are placed in a first finisher. The first finisher has a screen with apertures ranging in size from about 3 to about 5 mm in diameter. The first finisher also contains a plurality of bars and brushes to move the berries against the screen. The skin is extracted from the berry when the bars and brushes in the first finisher force the berries to be moved against the screen. The action of sliding the berries over the apertures in the screen removes the skin from the central portion of the berry. Contaminants larger than the aperture size of the screen are moved out of the first finisher and discarded
Once the skin is extracted from the fruit, the skin is separated from fiber and sand present from the extraction process in a second finisher. The second finisher has a second screen and a plurality of bars and brushes to slide the skin over the second screen. The second screen has a plurality of apertures having a diameter of from about 0.25 to about 1 mm. The skin fragments are broken down so that they pass through the second screen to separate out the fiber and sand. As the skin is slid against the apertures in the second screen, the skin is further broken down into small pieces, that are either dissolved into the juice present or passed through the second screen. Contaminants larger than the aperture size of the second screen are moved out of the second finisher and discarded. As will be recognized by one skilled in the art, the first and second finishers can be a single device.
After finishing, the mixture is warmed to a temperature of from about 40° C. to about 60° C., step 24. The mixture is then optionally centrifuged to remove trace amounts of lipids that are caused by inefficiencies in the extraction equipment, step 26.
The mixture is then de-aerated to reduce the dissolved oxygen level in the product and remove any free lipids from the liquid stream, step 28. De-aeration may be done by pumping the mixture into a vacuum chamber. The mixture is cascaded through an open space within the vacuum chamber in a manner that reduces the liquid particle size so that most oxygen entrained in the mixture can be removed by the vacuum. The mixture falls to the bottom of the chamber and is pumped out of the vacuum chamber. Vapors extracted from the mixture are condensed outside the vacuum chamber so that any volatile lipids may be eliminated.
The mixture is passed through a high shear mixer, colloid mill, homogenizer, hammer mill or disk grinder to break down the particles of skin and emulsify any remaining lipids, thereby resulting in production of juice, step 30. Preferably, the mixture is passed through a colloid mill. The colloid mill uses high shear to break down skin fragments into fruit juice. The mixture containing small skin fragments enters the colloid mill and is subjected to shear for a controlled amount of time based on the flow rate, motor speed and the space between a rotor and a stator of the mill. The shear induced in the mill breaks down particles to transform the particles into soluble solids incorporated in the liquid.
The juice is then subjected to pasteurization using a high temperature for a short period of time, step 32. Preferably, the juice is heated to from about 88 to about 95 degrees Celsius for from about 85 to about 120 seconds.
The pasteurized juice is then chilled, step 34. The chilled juice is then packaged, step 36. Optionally, the juice is filtered, such as through an 80 mesh screen prior to packaging. Optionally, the juice is frozen either prior to or following packaging.
Juice prepared according to the method of the present invention contains a higher concentration of anthocyanins than the pulp because the anthocyanins are only found in the skin layer of the fruit. Juice produced according to embodiments of the present invention has an anthocyanin concentration as measured as Oxygen Radical Absorption Capacity (ORAC) ranging from about 100,000 to about 300,000 micromoles of Trolox equivalents/liter). Preferentially, extracting the skin layer avoids dilution issues by the lipid/fiber layer and açaí sand. Also, extracting only the skin layer requires less water input which in turn leads to less dilution of the final product.
Juice produced according to the present invention has a lower extracted pH than pulp and is easily acidified to become a high acid material. Extracted juice can have a pH of about 5.0. After the addition of an acidulant, the juice preferably has a pH of less than about 4.4. The higher acidity of the acidified juice has minimal impact on the organoleptic evaluation of the product. The juice contains very low concentrations of fats, with a lipid content that is preferably less than about 1% on a dry weight basis. Moreover, the lipids are easily separated from the juice or stabilized by emulsifying the lipids into the juice. Preferably, açaí juice according to an embodiment of the present invention has a soluble solids content exceeding about three degrees brix, and more preferably exceeding about five degrees brix.
The inventive juice contains extremely low amounts of açaí sand, which is often undetectable in the final product. Due to the low viscosity of the juice, preferably between about 5 and about 20 centipoise, any remaining sand particles can be easily separated from the juice.
Additionally, the low viscosity of the juice product makes it an excellent candidate for concentration. Concentration stabilizes the anthocyanins and reduces shipping and storage costs of the finished product while making it easier to thaw in preparation for blending. Known methods such as membrane concentration and conventional evaporation can be used to concentrate the finished juice. Additionally, the juice is microbiologically stable and thaws easily from a frozen state, providing ample time for handling and blending without fermentation, rancidification or lipid separation problems.
Although the present invention has been described in considerable detail with reference to certain preferred versions thereof, other versions are possible. Therefore, the spirit and scope of the appended claims should not be limited to the description of the preferred versions described herein.
All features disclosed in the specification, including the claims, abstracts and drawings, and all the steps in any method or process disclosed, may be combined in any combination except combination where at least some of such features and/or steps are mutually exclusive. Each feature disclosed in the specification, including the claims, abstract, and drawings, can be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.
Any element in a claim that does not explicitly state “means” for performing a specified function or “step” for performing a specified function, should not be interpreted as a “means” or “step” clause as specified in 35 U.S.C. §112.
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A method for making juice from açaí berries having the steps of: chilling the berries to below about 10° C.; extracting a skin from the berries in an extractor with water to obtain a mixture; acidifying the mixture; finishing the mixture; heating the mixture to from about 40° C. to about 60° C.; de-aerating the mixture; passing the mixture through at least one of the group consisting of a high shear mixer, a colloid mill and a hammer mill to yield juice; and pasteurizing the juice.
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RELATED APPLICATIONS
[0001] The present application is related to provisional patent application Ser. No. 60/572,488 entitled “Turret Tool Holder for a Press” filed on May 20, 2004, priority from which is hereby claimed.
FIELD OF THE INVENTION
[0002] The present invention relates to a press used for the insertion of fasteners. More particularly it relates to an apparatus for changing the anvil tooling of an automated press for installing fasteners into panels such as sheet metal.
BACKGROUND OF THE INVENTION
[0003] Hydraulic punch presses as shown in FIG. 1 are often used as fastener insertion machines. These presses include a C-type frame 8 and have upper and lower tools 3 and 6 held in vertical alignment which come together on opposite sides of a flat panel workpiece 5 to install a fastener into the workpiece under pressure. The upper tool is carried by a press ram 2 which extends and retracts vertically while the lower tool 6 remains stationary, being affixed to an anvil 9 mounted on the lower jaw of the frame 8 opposite the workpiece 5 . The fasteners are typically delivered to the insertion site by escapement means 1 which holds each fastener against the end of the upper tool prior to insertion.
[0004] Individual tooling is specifically designed to install a particular type of fastener and since there are fasteners of different types and dimensions, separate tooling is required for installing each type. This therefore requires tooling changes when there is a change of fastener to be installed. It can become particularly problematic when one workpiece requires different types of fasteners. This requires either the tooling to be changed many times for each workpiece or for workpieces to be batched in lots and then re-run with a tooling change between each run. In either case, there are great inefficiencies and the increased opportunity for operator and/or workpiece handling errors.
[0005] In order to solve this problem, tool-changing devices have been created for fastener-installing punch presses such as disclosed in U.S. Pat. No. 6,106,446 issued to Kelly et al. and U.S. Pat. No. 6,135,933 issued to Kelly et al. These patents describe a tool-changing device in which a plurality of anvil tools may be interchanged by moving individual tools into and out of a tool clamp on the anvil. This requires rather complicated robotic handling of the individual tools which are delivered to the anvil site from a movable belt or other device that holds the individual tools in separate pockets below the anvil. When a tool is changed, the robotic device lifts the next tool out of a transfer pocket and into a clamp on the anvil to hold it in place. This system is very complex and expensive. More simplified anvil-mounted turret-type tool holders for punch presses are known, however they have no position-sensing means and cannot be used with monitoring controller software.
[0006] There is therefore a need in the art for a control system monitored tool-changing mechanism for a punch press which contains only a few components and which is rugged and reliable. Furthermore, there is a need for a rugged and reliable tool-changing system which is economical to manufacture and which provides position sensing means to ensure proper operation of the press.
SUMMARY OF THE INVENTION
[0007] In order to meet the above-stated need in the art, the present tool-changing system has been devised. The present device utilizes a rotary turret on which different tools are rigidly fixed. The turret includes a circular table base which is rotatably mounted on the top of the anvil which in turn is attached to the top of the bottom jaw of a C-frame punch press. As the turret is turned, a different tool is moved into the work zone in vertical alignment with the upper tool. The turret table can either be manually or motor driven in either direction between indexed operative positions.
[0008] Novel means have been created for sensing the position of the turret and indexing the turret to its next operating position. This indexing system utilizes only two simple sensors which are placed beneath the turret table. The sensors are held in a modular insert which is located within the anvil housing. Each sensor “reads” a different circular track on the underside of the turret table. Magnetic induction sensors are used in combination with grooves on the bottom of the turret table providing an extremely rugged and reliable position-sensing system. The present invention accommodates four tools per turret table, and with the possibility of interchangeable index tables, the invention permits any number of tool choices desired. The indexing system is preferably used in combination with quality assurance operating software which controls the operation of the press according to the selection of the proper tool, the delivery of the appropriate fasteners to the insertion site, and the number of fasteners to be inserted.
[0009] More specifically, the applicant has invented a rotary tool holder for a press comprising a press having an anvil including an assembly with means for rotatably mounting a substantially vertical axle. A rotary turret table is affixed to the axle and mounted above the anvil housing assembly. A plurality of vertically-extending tools are rigidly affixed to a top side of the turret table and the turret table is rotatable to a plurality of working positions defined by the points of rotation of the turret table where each of the plurality of tools is positioned directly beneath an upper tool of the press. The anvil assembly includes an index pin engageable with recesses in the bottom surface of the table when the table is in each working position. It also includes magnetic induction sensors responsive to position locating means on a bottom side of the table for indicating a working position of the table. The position locating means are arcuate grooves located along two concentric circular tracks in the bottom side surface of the table and integral with the table. Each of the tools are color-coded by colored panels located on the top side of the turret table adjacent each of the tools. The anvil assembly includes a housing secured to a lower jaw of a C-frame punch press. The system further includes a controller electrically connected to the sensors which pneumatically actuates the index pin into engagement with the recesses in the table when the sensors signal the controller that the table is in one of the working positions.
[0010] Greater detail of the invention will be shown in the following drawings which will describe the invention in detail. It should be understood however that there may be modifications and adaptations that will be apparent to those of ordinary skill in the art which fall within the spirit and scope of the invention.
DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is an overall view of a prior art punch press.
[0012] FIG. 2 is a close-up isometric view of the turret table mounting shown with four tools extending vertically from the top of the table.
[0013] FIG. 3 is a close-up of the anvil with the turret table removed which shows bearing means for receiving an axle which extends below the turret table. The two position-indicating sensors are also shown.
[0014] FIG. 4 shows an exploded isometric view of the turret table sensor insert and anvil housing which comprise the main components of the invention.
[0015] FIG. 5 shows a view of the underside of the turret table and the various grooves along two sensor tracks which provide table position signals.
[0016] FIG. 6 is a table which shows the decoding logic employed by the invention.
[0017] FIG. 7 is a timing chart which shows the output of the sensor signals labeled as A and B.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0018] Referring now to FIG. 2 , the turret table 10 which carries four different tools a, b, c, and d is mounted on top of anvil housing assembly 12 . The housing is in turn secured to the top of the lower jaw 14 of a C-frame type punch press. As the turret table is rotated, the tools (in this Figure tool a) move to an outermost point which is directly below and in vertical alignment with the upper tool 16 . The turret table may be either motor-driven or manually rotated in either direction. The press also includes fastener delivery means and an automated fastener holder 15 . The table rotates upon an axis defined by axle 18 which extends below the table and is secured by the anvil housing assembly. Signal wire 13 from the sensors passes from the back of the anvil housing and is connected to appropriate controller software which regulates operation of the machine. The table is preferably composed of a ferro-magnetic material such as steel.
[0019] Referring now to FIG. 3 , the anvil housing assembly 12 carries within it an insert 20 which holds magnetic induction type sensors 21 and 22 and also supports the axle of the turret table in bore 25 . The sensors which read the encoding structures on the bottom of the table are covered by the table and therefore protected from the industrial environment above. In this figure, the table locking mechanism which includes an index pin 24 is also shown. In the locked position, the index pin extends upward into one of four circular wells on the bottom of the turret table as shown in FIG. 5 . In the preferred embodiment, the index pin is biased by spring means upwardly into the locking position. Controller software signals a pneumatic actuator (not shown) that moves the pin downward and releases the table when the table is ready to be moved to the next indexed position. Cover plate 26 extends across the top of the anvil housing to cover the components not covered by the turret table.
[0020] A more detailed assembly drawing of the various structures previously discussed is shown in FIG. 4 . It can be seen from this illustration that the present invention provides a tool change system with an uncomplicated design that has very few parts. Only two sensors are used for the index positioning system which is therefore extremely rugged especially since the sensed features are merely grooves on the bottom of the turret table. The major components of the invention are mounted to a modular insert 20 that is secured within the anvil housing. Axle 18 is fitted to the turret table 10 and extends downward through washer and bearing assembly 45 being received in bore 25 of the anvil insert 20 . The sensors are also secured to the anvil insert and the entire assembly is fastened to the anvil housing 12 being protected by cover plate 26 . This design permits easy access to all components of the invention and allows simplified repair and ease of maintenance. Colored panels 43 adjacent each of the tools may be employed to color-code each tool position. The table color-coding may correspond to color-coding of the fastener supply to ensure that the correct fastener gets delivered only to the proper tool. The appropriate color may also be displayed or referenced on an operator display screen interface which is generated by the controller software.
[0021] Referring now to FIG. 5 , details of the bottom of the turret table are depicted. Arcuate grooves on the bottom of the table provide features to which the sensors respond. The grooves are located along two concentric circular tracks of different diameter. As shown in this drawing, groove 33 lies along a portion of an inner track and groove 34 lies along a portion of an outer track. Four circular wells 31 are located directly beneath each tool position and these recesses cooperate with the index pin 24 on the anvil assembly to properly locate the turret table in each of its four working positions.
[0022] The arcuate groove pattern on the bottom of the turret table provides the timing of the output signals from the sensors. One of the novel features of the invention is the turret table position-sensing decoding system which is achieved by the two magnetic induction sensors that “read” these grooves which are cut into the bottom of the turret table along two concentric circular tracks of different radii. The sensors detect the proximity of the table, i.e. the absence or presence of a groove adjacent the sensor. Hence, the signal from each sensor changes as a transition occurs from the grooved to the non-grooved areas of the table as they pass closely above it. This change of state is read as either an “on” or an “off” condition in the logic program illustrated in FIG. 6 . In order to determine the four absolute positions of the table at each tool position or station 90 degrees apart, the stations are assigned the combined signal states from the sensors at points when sensors A and B are either both “off” or both “on”. As described in FIG. 6 , the decoding logic also relies on recording the state just previous to reaching these points. FIG. 7 is a timing chart which shows the change of state table positions provided by the two sensors labeled A and B when grooves are placed and decoded according to the invention. The bars in the chart correspond to the location of the grooves adjacent each sensor as the turret table is rotated.
[0023] The present invention operates as follows. The invention is preferably used on a punch press which includes a touch screen interface that displays menus and accepts selections from the operator. By way of example, the operating system preferably used with the invention will have four stations of the turret table which are numbered and colored as for example number 1—Green, 2—Blue, 3—Yellow, and 4—Red. At each station separated by 90 rotational degrees of the turret table, a different anvil is located appropriate to a particular type of fastener to be installed.
[0024] After a “set-up” function is selected, the touch screen initiates a “tooling selection” that prompts the operator to select the desired tool feed sequence to be run at, for example, Station 1—Green. The tooling sequence can be automatic feed of nuts, studs, stand-offs, or double stroke nuts, or the tooling sequence can just be manual feed by the operator. The next screen displayed is titled “Size and Material” and prompts the operator to select the size fastener being installed at Station 1—Green and the material of the workpiece. This information is used to suggest a starting installation force for this station. The next screen displayed is titled “Job Set-Up” which prompts the operator to enter the quantity of fasteners being installed at each station, the installation force and dwell time for each of the four stations.
[0025] When all four stations are programmed, the next screen displayed is entitled “Locate Table” that prompts the operator to rotate the table to Station 1—Green if it is not already in that position. The press controller monitors the state of the two sensors under the table to determine the rotational location as explained above. When the table has arrived at the target station, the press controller releases the spring-loaded index pin which then extends upward into the index recess on the underside of the table into the anvil hole opposite the station. The index pin locks the table in the precise location for installation and prevents the table from rotating. When the controller senses that the table is at the correct station, the controller software proceeds to display the next screen, a “Safety Set-Up” screen, which prompts the operator to operate the foot pedal so the press controller can learn the safe position of the ramp to perform an install. Next, a “Run Mode” screen is displayed which includes running information for the selected station including station status, the fastener installation count for the station, the fastener's installation count for the workpiece, and other information. Installation of the fastener then proceeds until the run at the selected station is completed.
[0026] It should be understood that there may be other modifications and changes to the present invention that will be obvious to those of skill in the art from the foregoing description, however, the present invention should be limited only by the following claims and their legal equivalents.
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A tool-changing system for a press utilizes a rotary turret on which different tools are rigidly fixed. The turret includes a circular table base which is rotatably mounted on top of the press anvil. As the turret is turned, a different tool is moved into the work zone in vertical alignment with the upper tool on the press ram. The turret table can either be manually or motor driven in either direction between indexed operative positions. The indexing system which senses the position of the turret and indexes the turret to its next operating position uses only two simple sensors which are located beneath the turret table. Each sensor reads a different circular track on the underside of the turret table.
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FIELD OF THE INVENTION
[0001] The present invention relates generally to internal combustion engines, and more specifically to a two stroke barrel engine.
BACKGROUND
[0002] A barrel engine is a type of reciprocating engine that replaces the common crankshaft with a circular plate (the swashplate). Pistons press down on a circular plate in a circular sequence, forcing it to nutate around its center. The plate, also known as a wobble plate, is typically geared to produce rotary motion.
[0003] Barrel engines are differentiated from other engines in that the cylinders are arranged in parallel around the edge of the plate, and possibly on either side of it as well, and are aligned with the output shaft rather than at 90 degrees as in crankshaft engines. This design results in a very compact, cylindrical engine, ideally suited for use in aircraft engines.
DESCRIPTION OF THE DRAWINGS
[0004] One or more embodiments are illustrated by way of example, and not by limitation, in the figures of the accompanying drawings, and wherein:
[0005] FIG. 1 illustrates a barrel engine according to an embodiment; and
[0006] FIG. 2 is a diagram of a wobbleplate bearing illustrating an alternative anti-rotating arrangement.
DETAILED DESCRIPTION
[0007] FIG. 1 illustrates a longitudinal view and an end view of a barrel engine 100 according to one embodiment. The engine 100 features a two stroke barrel arrangement that includes a frame, i.e., cylinder block 25 , that houses an even number of cylinders encircling a power shaft 13 , wherein the centerlines of all the cylinders are parallel to each other. The cylinders operate in pairs, wherein each pair of cylinders comprises the two cylinders on opposite sides of power shaft 13 . Engine 100 further includes a wobbleplate drive system that includes two non-rotating wobbleplates 9 , each mounted on opposite ends of cylinder block 25 .
[0008] Each cylinder comprises a power cylinder comprising power sleeve 3 and a stepped charging cylinder comprising stepped sleeve 4 . Disposed within each power cylinder are opposing piston 1 and 2 . At a top stroke, a piston position encloses minimum cylinder volume; at a bottom stroke a piston position encloses maximum cylinder volume. Piston 1 is a power piston whose reciprocating motion drives power shaft 13 . Piston 2 , however, includes both a power piston and a stepped charging piston portion.
[0009] The cylinders operate in pairs opposite each other, wherein the stepped charging piston portion of piston 2 compresses inlet air to charge the two stroke power cylinder of the opposing paired cylinder.
[0010] At opposite ends of the power cylinder and at the bottom of the stroke, one of the power pistons 1 actuates an inlet port 8 b and the stepped power piston 2 actuates an exhaust port. The ports are configured such that exhaust port 8 a opens slightly before the inlet 8 a port. On the opposite side of wobbleplate 9 , stepped piston 2 opens an inlet port 6 from the carburetor at the bottom of it's stroke. At the top of it's stroke there is an always open outlet port 5 leading into a transfer passage 7 that connects with inlet port 8 b of the power piston it pressurizes.
[0011] The stepped piston 2 pressurizes the inlet air to charge the power cylinder of its paired cylinder. When the power piston's inlet port 8 b has opened for inlet, at the bottom of the stroke, the stepped piston 2 opposite is at the top of it's stroke, having compressed the fuel/air mixture.
[0012] The stepped charging piston 2 of one cylinder pressurizes the power cylinder of its paired cylinder. Accordingly, each stepped piston 2 moves in the opposite direction from its paired power piston 1 . The stepped piston can be large enough to produce more piston displacement than the power piston's displacement producing excess air for supercharging.
[0013] Intake port 5 is an input to the power cylinder by transfer passage 7 , and the stepped charging cylinder comprises intake port 6 from a carburetor. Transfer passage 7 connects the charging cylinder to a port 8 b of the power cylinder. The cylinder block further includes four split radial shaft main bearings 18 , a cooling water jacket 21 , a starter ring gear 22 , an accessory drive gear 23 , an end housing 24 , a split bore 26 in cylinder block 25 to assemble power shaft 13 into it's main bearings, spark plug bore 27 , and a shaft thrust bearing 17 .
[0014] The pistons disposed within each power cylinder include a power piston 1 and a combination power piston and stepped charging piston 2 . Connecting rods 14 connect each piston 1 , 2 to wobbleplates 9 via carden type two-pin universal joints at both ends of the connecting rod 14 . Because all of the pins handle the same load, the diameter of the pins is determined by the diameter of the piston wrist pins. Unlike a crankshaft connecting rod that experiences a violent lateral oscillation due to rotation of the crank, the connecting rods 14 do not need to be of the strong I-beam shape of crankshaft connecting rods. Accordingly, in one embodiment, connecting rods 14 are comprised of lightweight tubes having thick ends, the ends flattened and bored, wherein the hole for the pin goes through the thicker part of the flattened rod end. No welding or riveting is required.
[0015] As disclosed herein, wobbleplate 9 eliminates the need of piston rollers of previous wobbleplate designs and is designed according to a fatigue life determined by factors including the material used, stress in the shaft, and the number of its cycles experienced in its lifetime. Stress is based upon the value of the bending moment, caused by the spread of the main bearings 10 that straddle the wobbleplate 9 and the offset of the connecting rods 14 from the shaft center and the number of cycles experienced. The greater the bearing spread, the higher the bending moment value.
[0016] Wobbleplates 9 are restricted from rotating and receive force from each piston 1 , 2 equally spaced around the periphery of wobbleplate 9 by a connecting rod 14 having swiveled ends that cause wobbleplate 9 to wobble, thereby transferring the piston's reciprocating motion into rotary motion of power shaft 13 .
[0017] Each wobbleplate 9 is mounted via wobbleplate mounting bearing 10 to a slug 11 with a skewed bore, and is configured to transfer reciprocating motion from pistons 1 , 2 into rotary motion of power shaft 13 passing through slug 11 . Pin 12 secures slug 11 to power shaft 13 . Connecting rod 14 includes hinged ends mounted to hinged double pin carden joints. The hinged connection 15 of wobbleplate 9 to the connecting rod 14 allows angular motion of connecting rod 14 at the wobbleplate 9 . Hinged carden joint 16 includes a piston wrist pin.
[0018] Wobbleplates 9 are non-rotating. In the embodiment illustrated in FIG. 1 , anti-rotator rod 19 is fixed to, and extends radially from, the periphery of each wobbleplate 9 . Non-limiting, wobbleplate 9 is prevented from rotating by a pair of fixed planar members 20 straddling the anti-rotator rod 19 , the straddling members lying in planes parallel to the centerline of power shaft 13 and anchored to frame 25 of engine 100 . As wobbleplate 9 rocks, anti-rotator rod 19 slides always parallel to the centerline of power shaft 13 preventing wobbleplate 9 from rotating.
[0019] FIG. 2 illustrates another embodiment of an anti-rotator device wherein rotation of each wobbleplate 9 is prevented by a rotatable yoke 29 having at least one of its ends pivoted 90 degrees around a rotation restraint pin 31 mounted to the outside of wobbleplate 9 , and at least one other end of yoke 29 connected to frame 25 via attachment pin 30 . Rotation restraint pin 31 is configured to swivel into yoke 29 , allowing yoke 29 to rotate, while preventing the rotation of wobbleplate 9 .
[0020] Rotation restraint pin 31 , mounted to the periphery of wobbleplate 9 , oscillates, rotating twice the angle of wobbleplate 9 twice every revolution of shaft 13 as pin 31 slides back and fourth with the wobble. Furthermore, rotation restraint pin 31 carries the load of wobbleplate 9 from connecting rods 14 . Accordingly rotation restraint pin 31 is preferably lubricated by the surrounding load-carrying bushings.
[0021] In one embodiment, shaft 13 is hollow and contains oil under pressure. A groove disposed all the way around the inside bearing 10 allows oil to flow from skewed slug 11 through wobbleplate 9 to rotation restraint pin 31 or anti-rotator rod 19 .
[0022] In an alternate embodiment, a non-wobbling oil disc 28 is mounted on power shaft 13 between the wobbleplate 9 and the cylinder block. Unlike oil being dispersed from wobbleplate 9 , non-wobbling oil-disk 28 has an advantage of directing oil with greater accuracy without squirting oil in a trajectory determined by the wobble.
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A two-stroke barrel engine includes a power output shaft configured to rotate, an even number of cylinders encircling the power output shaft, wherein each cylinder includes opposing first and second power pistons configured to reciprocate within their respective power cylinder, and a pair of non-rotating wobbleplates opposed and hingedly connected to the power pistons. The wobbleplates are configured to transfer the reciprocating motion of the power pistons to rotary motion of the power output shaft via a nutating motion of the non-rotating wobbleplate.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is based on, claims the benefit of, and incorporates herein by reference in their entirety, PCT International Application PCT/US2009/065750 filed on Nov. 24, 2009, which claims benefit of U.S. Provisional Patent Application Ser. No. 61/117,705, filed on Nov. 25, 2008, entitled “System and Method for Analyzing the Carpal Tunnel Using Ultrasound.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH
This invention was made with government support under grant number AR049823, awarded by the National Institutes of Health. The government has certain rights in the invention.
FIELD OF THE INVENTION
The present invention relates to systems and methods ultrasonic imaging and, more particularly, to systems and methods for analyzing the health of structures within a subject's carpal tunnel using ultrasonic imaging methods.
BACKGROUND OF THE INVENTION
Carpal tunnel syndrome (CTS), which is a pressure induced neuropathy of the median nerve at the wrist, is a common clinical problem. The carpal tunnel is a sheath of tough connective tissue that protects and encloses a variety of structures, including the flexor tendons and the median nerve. Also within the carpal tunnel is the subsynovial connective tissue (SSCT), a specially adapted paratendon that mediates movement between the flexor tendons and the median nerve. The mechanical significance of the SSCT relates to its effect on the kinematics within the carpal tunnel and, as a framework for blood and lymph vessels, the SSCT plays a fundamental role in the nutrition of the structures embedded in it.
Studies have shown that SSCT motion characteristics and thickness differ between subjects with CTS and unaffected subjects. It is believed that an increased volume of the SSCT, especially if combined with altered transmission of tendon forces through the SSCT in the carpal tunnel, affects carpal tunnel pressure and therefore increases the likelihood of CTS.
Diagnostic ultrasonography has previously been used in confirming the diagnosis of CTS and in excluding other pathologies. Specifically, ultrasonography has been used to diagnose CTS, based on static images of nerve morphology. Static ultrasound imaging for CTS diagnosis can detect thickening and echogenicity alteration of the flexor tendons and flexor retinaculum, restricted median nerve sliding in the carpal tunnel, synovial proliferation, and flattening of the median nerve. However, static ultrasound imaging cannot assess dynamic features within the carpal tunnel, for example, tendon mechanics and pathomechanics. Thus, dynamic observations of the SSCT have traditionally required surgical exposure of the carpal tunnel and are not useful for the assessment of early changes in the SSCT in individuals affected by, or at risk for, CTS.
There are a number of modes in which ultrasound can be used to produce images of objects. For example in static, “B-scan,” ultrasound imaging, the transducer transmits a series of ultrasonic pulses as it is scanned across the object along a single axis of motion. The resulting echo signals are recorded and their amplitude is used to modulate the brightness of pixels on a display. The location of the transducer and the time delay of the received echo signals locates the pixels to be illuminated. With this static method, enough data are acquired from which a two-dimensional image of the refractors can be reconstructed. Rather than physically moving the transducer over the subject to perform a scan it is more common to employ an array of transducer elements and electronically move an ultrasonic beam over a region in the subject.
Another example is Doppler ultrasound imaging. Doppler systems employ an ultrasonic beam to measure the velocity of moving reflectors, such as flowing blood cells. Blood velocity is detected by measuring the Doppler shifts in frequency imparted to ultrasound by reflection from moving red blood cells. Accuracy in detecting the Doppler shift at a particular point in the bloodstream depends on defining a small sample volume at the required location and then processing the echoes to extract the Doppler shifted frequencies.
A Doppler system is incorporated in a real time scanning imaging system. The system provides electronic steering and focusing of a single acoustic beam and enables small volumes to be illuminated anywhere in the field of view of the instrument, whose locations can be visually identified on a two-dimensional B-scan image. A Fourier transform processor faithfully computes the Doppler spectrum backscattered from the sampled volumes, and by averaging the spectral components the mean frequency shift can be obtained. Typically the calculated blood velocity is used to color code pixels in the B-scan image.
Doppler imaging has been attempted to be used for assessing tendon velocity and excursion for hand and wrist motions. However, tissue Doppler imaging is a one-dimensional method that can only quantify the axial component of motion in an angle dependent manner. Doppler measurements lose its validity when the angle between the ultrasonic beam and the tissue exceeds a certain range. As a result, static ultrasonography and tissue Doppler imaging cannot adequately assess the condition of the SSCT and a subject's risk of developing CTS.
It would therefore be desirable to develop a system and method for non-invasively analyzing the carpal tunnel, and the SSCT in particular, that could be used to generate risk factors indicative of a subject's risk of developing carpel tunnel syndrome or SSCT damage.
SUMMARY OF THE INVENTION
The present invention overcomes the aforementioned drawbacks by providing a system and method for analyzing the health of a subject's carpal tunnel without invasive analysis. Specifically, the present invention provides a system and method for performing ultrasound analysis of a subject's carpal tunnel by arranging a subject within an examination apparatus, acquiring a plurality of time series of ultrasound images of the subject's carpal tunnel as the subject performs a series of tasks controlled by the examination apparatus and performing speckle tracking on the time series of ultrasound images. The speckle tracking is then analyzed to determine a plurality of functional parameters of the subject and statistical analysis is performed to compare the functional parameters of the subject to a priori functional parameters from normal subjects and subjects having carpal tunnel syndrome. Thereby, risk factors indicative of the subject's risk of developing carpal tunnel syndrome or subsynovial connective tissue damage are generated.
In accordance with one aspect of the invention, a system is provided for generating a report indicating a subject's risk for developing a disorder of a carpal tunnel. The system includes an examination apparatus configured to control motion of the subject through a predetermined set of motions, an ultrasound transducer arranged proximate to the subject's carpel tunnel to acquire a time series of medical imaging data of a region of interest including at least a portion of the subject's carpel tunnel, and a processor configured to receive the time series of medial imaging data. The processor includes instructions configured to cause the processor to carry out the steps of generating a time series of images from the time series of medial imaging data and receiving an indication of anatomical features within the time series of medical images. The processor also carries out the steps of analyzing the time series of medical images to determine indicia of acoustic signals arising from coherent reflection of ultrasound waves generated by the transducer from predetermined features within the region of interest and track the determined indicia across the time series of medical images. Also, the processor carries out the steps of determining a pattern of motion of the determined indicia across the time series of medical images, generating a series of functional parameters characterizing pattern of motion of the determined indicia across the time series of medical images, and, using the series of functional parameters, generating a report indicating the subject's risk of developing at least one of carpel tunnel syndrome (CTS) and subsynovial connective tissue (SSCT) damage.
Various other features of the present invention will be made apparent from the following detailed description and the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of an ultrasonic imaging system configured to employs the present invention;
FIG. 2 is a block diagram of a transmitter that forms part of the system of FIG. 1 ;
FIG. 3 is a block diagram of a receiver that forms part of the system of FIG. 1 ;
FIG. 4 is a flowchart setting forth the steps of a method for generating risk factors indicative of a subject's risk of developing CTS or SSCT damage using an ultrasonic imaging system in accordance with the present invention;
FIG. 5 is a perspective view of an examination apparatus for use with the ultrasonic imaging system of FIG. 1 in accordance with the present invention; and
FIG. 6 is an exemplary image showing the tracking of features within the carpal tunnel using methods in accordance with the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1 , an ultrasonic imaging system includes a transducer array 11 comprised of a plurality of separately driven elements 12 which each produce a burst of ultrasonic energy when energized by a pulse produced by a transmitter 13 . The ultrasonic energy reflected back to the transducer array 11 from the subject under study is converted to an electrical signal by each transducer element 12 and applied separately to a receiver 14 through a set of switches 15 . The transmitter 13 , receiver 14 and the switches 15 are operated under the control of a digital controller 16 responsive to the commands input by the human operator. A complete scan is performed by acquiring a series of echoes in which the switches 15 are set to their transmit position, the transmitter 13 is gated on momentarily to energize each transducer element 12 , the switches 15 are then set to their receive position, and the subsequent echo signals produced by each transducer element 12 are applied to the receiver 14 . The separate echo signals from each transducer element 12 are combined in the receiver 14 to produce a single echo signal which is employed to produce a line in an image on a display system 17 .
The display system 17 receives the series of data points produced by the receiver 14 and converts the data to a form producing the desired image. For example, if an A-scan is desired, the magnitude of the series of data points is merely graphed as a function of time. If a B-scan is desired, each data point in the series is used to control the brightness of a pixel in the image, and a scan comprised of a series of measurements at successive locations along the length of the transducer 11 (linear array mode) or steering angles (PASS mode) is performed to provide the data necessary for display.
Referring particularly to FIG. 2 , the transmitter 13 includes a set of channel pulse code memories which are indicated collectively at 50 . Each pulse code memory 50 stores a bit pattern 51 that determines the frequency of the ultrasonic pulse 52 that is to be produced. This bit pattern is read out of each pulse code memory 50 by a master clock and applied to a driver 53 which amplifies the signal to a power level suitable for driving the transducer 11 . In the example shown in FIG. 2 , the bit pattern is a sequence of four “1” bits alternated with four “0” bits to produce a 5 MHz ultrasonic pulse 52 . The transducer elements 11 to which these ultrasonic pulses 52 are applied respond by producing ultrasonic energy.
As indicated above, to steer the transmitted beam of the ultrasonic energy in the desired manner, the pulses 52 for each of the N channels must be produced and delayed by the proper amount. These delays are provided by a transmit control 54 which receives control signals from the digital controller 16 of FIG. 1 . When the control signal is received, the transmit control 54 gates a clock signal through to the first transmit channel 50 . At each successive delay time interval thereafter, the clock signal is gated through to the next channel pulse code memory 50 until all the channels to be energized are producing their ultrasonic pulses 52 . Each transmit channel 50 is reset after its entire bit pattern 51 has been transmitted and the transmitter 13 then waits for the next control signal from the digital controller 16 .
Referring particularly to FIG. 3 , the receiver 14 is includes three primary sections including a time-gain control section 100 , a beam forming section 101 , and a mid processor 102 . The time-gain control section 100 includes an amplifier 105 for each of the N receiver channels and a time-gain control circuit 106 . The input of each amplifier 105 is connected to a respective one of the transducer elements 12 to receive and amplify the echo signal which it receives. The amount of amplification provided by the amplifiers 105 is controlled through a control line 107 that is driven by the time-gain control circuit 106 . As is well known in the art, as the range of the echo signal increases, its amplitude is diminished. As a result, unless the echo signal emanating from more distant reflectors is amplified more than the echo signal from nearby reflectors, the brightness of the image diminishes rapidly as a function of range (R). This amplification is controlled by the operator who manually sets TGC linear potentiometers 108 to values which provide a relatively uniform brightness over the entire range of the scan. The time interval over which the echo signal is acquired determines the range from which it emanates, and this time interval is divided into segments by the TGC control circuit 106 . The settings of the potentiometers are employed to set the gain of the amplifiers 105 during each of the respective time intervals so that the echo signal is amplified in ever increasing amounts over the acquisition time interval.
The beam forming section 101 of the receiver 14 includes N separate receiver channels 110 . Each receiver channel 110 receives the analog echo signal from one of the TGC amplifiers 105 at an input 111 , and it produces a stream of digitized output values on an I bus 112 and a Q bus 113 . Each of these I and Q values represents a sample of the echo signal envelope at a specific range (R). These samples have been delayed in the manner described above such that when they are summed at summing points 114 and 115 with the I and Q samples from each of the other receiver channels 110 , they indicate the magnitude and phase of the echo signal reflected from a point P located at range R on the ultrasonic beam.
Referring still to FIG. 3 , the mid processor section 102 receives the beam samples from the summing points 114 and 115 . The I and Q values of each beam sample is a digital number which represents the in-phase and quadrature components of the magnitude of the reflected sound from a point P. The mid processor 102 can perform a variety of calculations on these beam samples, where choice is determined by the type of image to be reconstructed. For example, if a conventional magnitude image is to be produced, a detection process indicated at 120 is implemented in which a digital magnitude M is calculated from each beam sample and output at 121 .
M =√{square root over ( I 2 +Q 2 )}
The detection process 120 may also implement correction methods, for example, such as that disclosed in U.S. Pat. No. 4,835,689. Such correction methods examine the received beam samples and calculate corrective values that can be used in subsequent measurements by the transmitter 13 and receiver 14 to improve beam focusing and steering. Such corrections are desirable, for example, to account for the non-homogeneity of the media through which the sound from each transducer element travels during a scan.
The mid processor may also include a Doppler processor 122 . Such Doppler processors often employ the phase information (φ) contained in each beam sample to determine the velocity of reflecting objects along the direction of the beam (i.e. direction from the transducer 11 ), where φ=tan −1 (I/Q).
The mid processor may also include a correlation flow processor 123 , such as that described in U.S. Pat. No. 4,587,973, issued May 13, 1986 and entitled “Ultrasonic Method Can Means For Measuring Blood Flow And The Like Using Autocorrelation”. Such methods measure the motion of reflectors by following the shift in their position between successive ultrasonic pulse measurements.
As appreciated by one of ordinary skill, the above-described system can be used to perform a number of imaging studies. In accordance with the present invention, the system may be designated to analyze the tissues of the carpal tunnel and generate risk factors indicative of a subject's risk of developing CTS or SSCT damage.
Referring to FIGS. 4 and 5 , a general method for ultrasound analysis of CTS risk factors starts and, at process block 500 , a subject 600 is prepared for scanning. Specifically, the forearm of the subject is fasted to an examination apparatus, indicated generally at 602 , and the transducer head of an ultrasound probe 604 is placed just proximal to the subject's wrist flexion crease and its position is maintained by an ultrasound holding mechanism 606 that is included in the examination apparatus 600 . The examination apparatus 600 further includes objects, for example, a gripping devices 608 , which may, as illustrated, be a series of acrylic tubes having varying diameters, that a subject manipulates to perform a task, for example, flexing and extending the wrist to grip and release the varying tubes. The examination apparatus 602 is designed to permit desired motion of the subject but restrict undesired motion. It is contemplated that the subject may be trained to perform these tasks repeatedly and consistently, such as using a metronome marking a beat, for example, 0.80 Hz, for flexion and extension.
Referring still to FIG. 4 , at process block 502 , a time series of ultrasound images is acquired at a specified acquisition rate as the subject performs a task. For example, an ultrasound image may be acquired seventy times each second, providing a 70 Hz image acquisition rate. The tasks generally involve manipulating an object so as to cause flexion and extension of the structures within the carpal tunnel. To improve results and account for any abnormal subject motion, it is contemplated that the subject may repeat the task at least three times while a time series of ultrasound images is acquired. It is further contemplated that imaging is performed using an ultrasound scanner equipped with a 15L8 linear array transducer set to a depth of 20 mm with a 14 MHz image acquisition frequency. At process block 506 , the examination apparatus, and the subject's position within the apparatus, are changed so the subject may perform additional tasks. For example, if the subject is flexing and extending their wrist around an acrylic tube, the acrylic tube may be removed from the examination apparatus and replaced with an acrylic tube having a different diameter. This step may further include repositioning the subject within the examination apparatus to allow ultrasound imaging to be performed on the other forearm. At process block 502 , the subject performs the new task while a time series of ultrasound images is acquired. The steps in process block 502 and 506 are repeated until, at decision block 504 , it is decided that an appropriate number of tasks and ultrasound scans have been performed.
At process block 508 , the acquired ultrasound data is preprocessed. Processing includes image compression, truncating the time series of ultrasound images so that only relevant time frames remain, and altering the frame rate of the time series as it is recorded to a computer system. For example, the image acquisition frame rate may be at 70 Hz. However, when operating the ultrasound machine in ‘cine’ function, where the frames for the previous few seconds are stored in cine memory, regularly, the play speed is slowed down to 37 percent of its original speed. This is because, if the cine images were saved without reduction of the play speed, some of the frames will be truncated during the image saving process. To minimize the flame reduction, the play speed is, thus, slowed down to 37 percent of its original speed.
Referring to FIGS. 4 and 6 , speckle tracking is performed on the processed time series of ultrasound images at process block 510 . Speckle tracking is an angle-independent, two-dimensional dynamic ultrasonic imaging technique that analyzes the motion of a tissue by tracking speckles, which are acoustic signals that arise from the coherent reflection of ultrasound waves off small features, for example, very small cells, in a subject. Speckles are tracked from frame to frame in a time series of ultrasound images with an optimized pattern-matching algorithm, allowing the analysis of dynamic features, for example, the motion of fluid and tissues, by reconstructing the deformation and motion of the speckles.
Anatomical features within the carpel tunnel are tracked by placing tracking markers 700 on speckles within portions of the image containing structures of interest, for example, the flexor digitorum superficialis (FDS) and the SSCT. It is contemplated that three markers may be placed on the FDS tendon tissue speckles, perpendicular to the direction of tendon motion, with a distance between the two furthest markers of one millimeter. The SSCT, a highly echogenic layer at the border of the tendon, is normally thinner than 1 mm and may be tracked by placing markers at the following locations: one at the border between the tendon and the highly echogenic layer; one within the highly echogenic layer; and one at the outer border of the highly echogenic layer. These markers define what is considered a representative segment of the SSCT. Following placement of the markers, speckle tracking software implements a desired optimized pattern-matching algorithm to track the areas bounded by the applied markers. For example, the paths 702 show the motion of the tracking markers 700 through the course of a time series of ultrasound images.
At process block 512 , the results of speckle tracking are analyzed and a series of functional parameters characterizing the motion of the tracked structures are generated. Speckle tracking should show a clear difference in the direction of motion of structures within the carpal tunnel between periods of flexion and periods of extension. Therefore, tracking points that most strongly display this difference are selected and analyzed to generate a series of functional parameters characterizing the motion of the tracked structures. For example, velocity and strain time series, may be calculated for the FDS and SSCT. From these time series, the maximum velocities and excursions of the FDS and SSCT may be calculated. Additional functional parameters, such as the maximum velocity ratio, which is the ratio of the SSCT maximum velocity relative to the FDS maximum velocity, and the shear index may be generated. The shear index, which represent SSCT displacement relative to FDS displacement, may be calculated by the following equation:
Shear index=[(Excursion FDS −Excursion SSCT )/(Excursion FDS )]*100 percent
Still referring to FIG. 4 , following the generation of the functional parameters statistical analysis is performed at process block 514 . The statistical analysis compares the functional parameters acquired from a subject to a priori functional parameters obtained from normal subjects and subjects having CTS. At process block 516 , the results of the statistical analysis are used to generate risk factors indicative of a subject's risk of developing CTS or SSCT damage. The motion patterns of the SSCT relative to the flexor tendon are known to be different in CTS patient compared to normal subject. This suggests shear condition of the SSCT may be different between CTS patients and normal subjects. By analyzing the difference in the relative motion of SSCT, subjects with a predisposition for CTS, for example, subjects having a normal median nerve but a structurally abnormal SSCT can be identified.
The present invention has been described in terms of one or more preferred embodiments, and it should be appreciated that many equivalents, alternatives, variations, and modifications, aside from those expressly stated, are possible and within the scope of the invention.
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A system and method is provided for using dynamic ultrasonic imaging to analyze a subject's carpal tunnel and generate risk factors indicative of the health of the subject's subsynovial connective tissue and the subject's risk of developing carpal tunnel syndrome. The system and method uses speckle imaging techniques to track dynamic structures within the carpal tunnel and statistical analysis techniques to compare the properties of these dynamic structures of the subject to those of normal subjects and subjects having carpal tunnel syndrome.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a door operator, more particularly to a door operator for a fireproof door.
2. Brief Description of Prior Art
Generally, the door operator used in a fireproof door is classified into two types depending on its operational mode: one is a failsafe mode and the other is a non-failsafe mode. In the case of the failsafe mode, a brake is immediately released by a brake device so as to shut the fireproof door in the absence of electrical power regardless of the reason of power failure. If fire breaks out in the presence of electrical power, the power is cut off by, for example, smoke detectors, temperature sensors or other fire detecting devices, or is cut off mechanically by a fusible link device which is molten at a high temperature in the fire in such a manner that the brake is released, and the door curtain shuts the fireproof door by its own weight. In this mode, the flame or escape of dense smoke can be blocked instantly when the fire occurs, if the cause of power failure is a fire indeed. Therefore, the main feature of the failsafe mode is more active for fire prevention. However, if the cause of the power failure is not a fire, a manually operating means has to be used for driving the door operator to open the door so as to maintain regular access for personnel.
On the other hand, in non-failsafe mode, the brake device is still maintained in a brake-actuated state without closing the fireproof door immediately in the absence of electrical power, regardless of the reason of power failure. Only if the occurrence of a fire is definitely confirmed by, for example, smoke detectors, temperature sensors or other fire detecting devices, a current transiently supplied from a reserved power source such as a capacitor, a battery or the like is supplied to the brake device for releasing the brake for a short period of time, or a fusible link is molten at a high temperature for mechanically actuating the brake device so as to release the brake, in such a manner that the door curtain falls down and shuts the fireproof door by its own weight. In this mode, the main advantage is that no inconvenience is encountered for personnel regular access is the main advantage, if the fire is not the cause of power failure. However, if the power failure is caused by a fire, and if the fire point is remote from the fire detecting devices or the fusible link, it is impossible to close the fireproof door immediately. Therefore, this mode is less safe for fire prevention.
Some documents associated with a failsafe mode door operator of a fireproof door have been proposed, such as U.S. Pat. Nos. 5,673,514 and 5,893,234 in which two electromagnets are used to maintain the brake-actuating state in the presence of electrical power, or to release the brake immediately so as to close the fireproof door in a power failure condition. The structure thereof is very complicated and has a large volume. On the other hand, a lot of documents concerning non-failsafe mode door operator of fireproof door such as U.S. Pat. Nos. 5,203,392 and 5,386,891 are disclosed, in which manual operation has to be conducted by switching operation mode, or a chain disk is rotated by pulling an endless chain and meanwhile the brake is released so as to rotate the rotary shaft. Thus, there is still room for further improvements on the implementation and the structure of a door operator.
SUMMARY OF THE INVENTION
The main object of the present invention is to provide a novel door operator of a fireproof door capable of obviating the disadvantages such as complexity in structure, large volume and inconvenience in operation present in prior art.
In order to achieve the aforementioned and the other objects, the door operator of the fireproof door according to the present invention comprises: a force applying end, which is activated to drive a rotary shaft; and a loading end for supporting the weight of the door curtain, the rotary shaft comprising an internal shaft and an external shaft. The force applying end and the loading end are applied on the internal shaft and the external shaft respectively, and the internal shaft and the external shaft are normally coupled by a clutch mechanism. A torsion spring brake mechanism is used to normally brake or release the rotary shaft by reducing or enlarging the inner diameter of the torsion spring. When an external force is exerted on the force applying end in a manner that the torsion spring is de-twisted or its inner diameter is enlarged, the rotary shaft is released and rotated. In the case that no external force is exerted thereto, the loading from the weight of the door curtain is normally transferred to the torsion spring so that the torsion spring is twisted or its inner diameter is reduced, whereby braking the rotary shaft. In this way, the clutch mechanism is controlled to interrupt the coupling of the internal shaft and the external shaft such that the door curtain falls and shuts the fireproof door in the event of a fire alarm. Thus, flame or smoke can be blocked immediately.
According to the present invention, each end of the torsion spring is provided with a protrusion loop having a twisting side and a de-twisting side. The external force exerted from the force applying end is applied on the de-twisting side so that the torsion spring is de-twisted or its inner diameter is enlarged and the rotary shaft is released and rotated by the external force. Alternatively, the loading on the loading end from the weight of the door curtain is applied on the twisting side so that the torsion spring is twisted or its inner diameter is reduced to brake the rotation of the rotary shaft caused by the weight of the door curtain. With aid of the torsion spring brake mechanism, not only is the external force allowed to roll up or down the door curtain, but also the rotation of the rotary shaft caused by the weight of the door curtain is braked.
According to the present invention, the rotary shaft of the door operator is simplified and compact in structure by arranging the internal shaft in the external shaft.
According to the present invention, the door operator of the fireproof door can be adapted to a failsafe door operator by introducing an electromagnetic clutch or into a non-failsafe door operator by introducing a mechanical clutch. Most of the components used in both cases are the same. Not only lower manufacturing cost, fewer components and simplicity in production can be achieved, but also smaller inventory and simplicity in assembly can be realized.
According to the present invention, the door operator of the fireproof door further has a circuit by which the electromagnetic clutch can be excited in the presence of a normal power supply. The circuit may further include a delay circuit formed by a plurality of capacitors, which are charged in the presence of the normal power supply. In the event of a power interruption caused by a fire, the electromagnetic clutch can be excited for a short time excitation so as to delay shutting of the fireproof door for the personnel evacuation.
BRIEF DESCRIPTION OF ACCOMPANYING DRAWINGS
FIG. 1 is a sectional view showing the door operator of a failsafe type fireproof door according to the present invention.
FIG. 1 a is a partially enlarged view of the encircled portion in FIG. 1 in which the clutch mechanism is shown to be in a separated state.
FIG. 1 b is a partially enlarged view of the encircled portion in FIG. 1 in which the clutch mechanism is shown to be in an engaged state.
FIG. 1 c is a sectional schematic view taken along the line 1 c - 1 c of FIG. 1 .
FIG. 1 d is a perspective sectional view showing the door operator of FIG. 1 .
FIG. 1 e is an exploded perspective view showing the torsion spring brake mechanism of the present invention.
FIG. 1 f is an exploded perspective enlarged view in another direction showing the torsion spring brake mechanism in FIG. 1 e of the present invention.
FIG. 1 g is a schematic view showing a circuit used in the door operator of a failsafe type fireproof door according to the present invention.
FIG. 1 h is a schematic drawing showing the state of use of the present invention.
FIG. 1 i is a sectional view taken along the line 1 i - 1 i in FIG. 1 d.
FIG. 2 is a sectional view showing an embodiment of a non-failsafe type door operator of fireproof door of the present invention.
FIG. 2 a is a schematic sectional view taken along the line 2 a - 2 a in FIG. 2 .
FIG. 2 b is a dynamic schematic view of the clutch mechanism in FIG. 2 in which the clutch mechanism is shown to be in separated state.
FIG. 2 c is a sectional perspective view showing the door operator in FIG. 2 .
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The technical contents of the present invention will become more apparent from the detailed description of the preferred embodiments in conjunction with the accompanying drawings. It is noted that the preferred embodiments which are purely illustrative do not intend to restrict the implementation range of the present invention.
Firstly referring to FIGS. 1 , 1 a to 1 i , an embodiment of a failsafe type door operator of a fireproof door of the present invention is described. The door operator 1 of the present invention is used to release a reel A of a door curtain D so as to close the fireproof door in the event of power failure. The door curtain is composed of a plurality of slats. The door operator 1 essentially comprises a housing 10 defining an accommodation space. A central shaft 12 is rotatably arranged in the housing 10 . A torsion spring brake mechanism 20 is arranged to encircle around the circumference at the left end of the central shaft 12 for braking or releasing the central axis 12 by twisting or de-twisting one or more torsion springs 201 of the torsion spring brake mechanism 20 . The details of the torsion spring brake mechanism 20 will be described later. A drive mechanism 30 is disposed on the central shaft 12 in such a manner that the torsion springs 201 is de-twisted to the effect that the inner diameter thereof is enlarged when an external force is exerted on the drive mechanism 30 whereby releasing and rotating the central shaft 12 . A first external shaft 14 is rotatably mounted on the central shaft 12 . A clutch mechanism 50 is disposed on the central shaft 12 at the right end of the first external shaft 14 for connecting and disconnecting the central shaft 12 and the first external shaft 14 in a control manner. A second external shaft 16 adjacent to the left end of the first external shaft 14 is rotatably mounted on the central shaft 12 and firmly provided with an output pulley 161 which is coupled with the reel A of the door curtain D (as shown in FIG. 1 h ). A reduction mechanism 40 includes gear trains 401 , 401 ′. As shown in FIG. 1 i , a first external shaft 14 is coupled to a second external shaft 16 through gear 401 , gear 401 a , gear 401 b and gear 401 ′ in sequence so as to reduce the speed of the first external shaft 14 , and transfer the reduced speed to the second external shaft 16 . When no external force is exerted on the drive mechanism 30 , the loading from the weight of the door curtain is normally transmitted to the torsion spring 201 through the output pulley 161 , the second external shaft 16 , the reduction mechanism 40 , the first external shaft 14 , the clutch mechanism 50 and the central shaft 12 so that the torsion springs 201 are twisted to the effect that the inner diameter thereof is reduced, whereby braking and holding the central shaft 12 . In the event of the fire alarm and power failure, the clutch disconnects the first external shaft 14 from the central shaft 12 such that the door curtain falls down by its own weight and shuts the fireproof door.
According to the present invention, a centrifugal brake mechanism 60 , which is well known, is arranged to encircle the outer circumference of the first external shaft 14 for limiting the rotation speed of the first external shaft 14 by a friction on the brake drum caused by a centrifugal force. The centrifugal force is generated when the first external shaft 14 rotates. The housing 10 is partitioned into a plurality of spaces by a plurality of partitioning plates 101 , 101 ′. The brake drum 601 is fixed on one of the partitioning plates 101 . One end of the first external shaft 14 is rotatably and is centrally aligned with the brake drum 601 , while the other end is provided with a driven disc 141 .
The clutch mechanism 50 is located on the opposite side of the driven disc 141 which comprises an electromagnet 501 fixed on the other one of the partitioning plates 101 ′ of the housing 10 . A drive member 503 has an end face adjacent to the electromagnet 501 and is fixed on the central shaft 12 . A follower 505 which is provided with a brake shoe 533 and interposed between the drive member 503 and the driven disc 141 is biased by an elastic plate 507 and is coupled with the driven disc 141 . When the electromagnet 501 is not excited, the follower 505 is biased toward the driven disc 141 , as shown in FIG. 1 a . At the same time, the coupling of the central shaft 12 and the first external shaft 14 is disconnected. On the other hand, when the electromagnet 501 is excited, the follower 505 is pushed toward the drive member 503 by the electromagnet 501 against the elastic plate 507 , as shown in FIG. 1 b . In the same time, the central shaft 12 and the first external shaft 14 are coupled. Moreover, a circuit is provided to excite the electromagnet 501 in the presence of the normal power supply, so that the central shaft 12 and the first external shaft 14 are normally coupled.
Furthermore, the housing 10 is provided with a second housing 10 ′ for supporting one end of the second external shaft 16 , and the torsion spring brake mechanism 20 is received in the second housing 10 ′. The torsion spring brake mechanism 20 is provided with a hub 18 which rotatably supports one end of the central shaft 12 . One end of the hub 18 is fixed on the second housing 10 ′. As shown in FIGS. 1 e and 1 f , the torsion spring brake mechanism 20 has one or more torsion springs 201 . Two ends of each torsion spring 201 are free ends. Each torsion spring 201 constricts the circumference of the other end of the hub 18 . Each free end of each torsion spring 201 is formed with a protrusion loop 201 a . An inner ring portion 203 and an outer ring portion 205 are concentric and rotatable with respect to each other. The inner ring portion 203 is fitted and fixed on the central shaft 12 . A pair of blocking plates 2031 are erected on one top face of the inner ring portion 203 in the longitudinal direction and arranged opposite to each other in the radial direction. A pair of push-plates 2051 are erected on one top face of the outer ring portion 205 at the same side with the blocking plates 2031 and arranged opposite to each other in the radial direction in such a matter that the blocking plates 2031 and the push-plates 2051 are disposed alternately around the torsion springs 201 . The blocking plates 2031 and the push-plates 2051 are concentric and arranged at the same radius. The protrusion loop 201 a is received in a gap between one blocking plate 2031 and one push-plate 2051 which are adjacent to each other. Each protrusion loop 201 a has a twisting side a and a de-twisting side b. The “twisting side” refers to as the side on which a force is exerted, causing the torsion to be twisted. The “de-twisting side” refers to as the side on which a force is exerted, causing the torsion to be de-twisted. The blocking plates 2031 are respectively arranged between two twisting sides a and would be blocked by the twisting sides a. Rotation of the outer ring portion 205 causes the push-plates 2051 to be abutted on the de-twisting sides b and hence causes the torsion springs 201 to be de-twisted as shown in FIG. 1 c so that the rotation of the outer ring portion 205 is kept going. In addition, the drive mechanism 30 includes a chain wheel 301 and a chain wound on the outer circumference of the chain wheel 301 . The chain wheel 301 is fixed on the outer ring portion 205 .
The central shaft 12 can be indirectly rotated by pulling the chain.
Referring to FIGS. 1 and 1 g , the coil R 1 of the electromagnet 501 of the clutch mechanism 50 is excited in the presence of the normal power supply such that the central shaft 12 and the first external shaft 14 are coupled with each other normally. At this moment, if the chain is pulled, then the push-plates 2051 are rotated and abutted on the de-twisting sides b of the protrusion loops 201 a of the torsion springs 201 so that the torsion springs 201 are subject to a de-twisting torque and hence de-twisted. The inner diameter of the torsion springs 201 is enlarged and the hub 18 is released from the torsion springs 201 . Then, the torsion springs 201 are rotated along the circumference of the hub 18 , so the blocking plates 2031 on the other side of the protrusion loops 201 a are also rotated together. The drive force applied on the central shaft 12 is transferred through the first external shaft 14 and the second external shaft 16 to the reel of the door curtain so as to roll up or down the door curtain. On the other hand, if the drive mechanism 30 is not operated, the loading of the weight of the door curtain on the output pulley 161 is transferred to the central shaft 12 through the first external shaft 14 and the second external shaft 16 . In such a case, the blocking plates 2031 of the inner outer portion 203 are abutted on the twisting sides a of the protrusion loops 201 a of the torsion springs 201 so that a twisting torque is applied to the torsion springs 201 and the torsion springs 201 are further twisted. As the torsion springs 201 are further twisted, the torsion springs 201 constrict on the hub 18 more firmly and hence become unmovable and unrotatable about the hub 18 . As a result, the blocking plates 2031 are blocked by the unmovable and unrotatable torsion springs 201 , and hence the central shaft 12 is braked and held.
In the event of power failure, the clutch mechanism 50 immediately interrupts the coupling of the central shaft 12 and the first external shaft 14 such that the door curtain falls down by its own weight. Even when fire breaks out in the presence of the power supply, the power supply can be interrupted by conventional fire detecting devices, for example, smoke detectors, temperature sensors or other fire detecting devices. Furthermore, a delay circuit C 1 formed by a plurality of capacitors may be included in the circuit. The capacitors which are charged in the presence of the power supply supply a current to the coil R 1 of the electromagnet 501 for a short time in the event of the power failure the electromagnet 501 is excited transiently, for example for about 10 seconds, so as to delay the shutting of the fireproof door for immediate personnel evacuation.
Furthermore, FIGS. 2 to 2 c illustrate an embodiment of a non-failsafe door operator of a fireproof door of the present invention. This embodiment different from the preceding one in that a mechanical type of clutch mechanism 50 ′ is included to couple the central shaft 12 and the first external shaft 14 or disconnect them from each other. According to this invention, the other end of the central shaft 12 is rotatably support on the other partitioning plate 101 ′ at the outer side of the partitioning plate 101 ′. The clutch mechanism 50 ′ has a bushing 52 disposed on the right side of the driven disc 141 . The bushing 52 is arranged in such a manner that the bushing 52 can slide axially therein and rotate together with the central shaft 12 , but cannot rotate with respect to the central shaft 12 . A circumferential sliding groove 521 is formed along the outer circumference of the bushing 52 . A disk spring 54 is interposed between the bushing 52 and the partitioning plate 101 ′. One end of the bushing 52 is biased by the disk spring 54 such that the other end thereof is normally abutted against the driven disk 141 . A first teeth portion 141 a is formed on the end face of the driven disk 141 which is to be engaged with a second teeth portion 523 formed on the end face of the other end of the bushing 52 , as shown in FIGS. 2 and 2 a.
According to the present invention, a rocking lever 56 is provided. The middle portion of the rock lever 56 is pivoted on the housing 10 . The inner end of the rocking lever 56 is provided with a protruding pin 561 extending into the sliding groove 521 . The outside end of the rocking lever 56 extends outside of the housing 10 . A guide member 57 is fixed on the housing 10 corresponding to the outer end of the rocking lever 56 . A slider 58 inserted in the guide member 57 is slidably guided in the guide member 57 . The slider 58 is biased by an elastic element 59 and connected with a conventional fire detecting device 70 . The slider 58 is arranged in place so that the outer end of the rocking lever 56 can be operated by one end of the slider 58 . The slider 58 is held by the fire detecting device 70 so that the slider 58 is not abutted to the rocking lever 504 . The fire detecting device 70 may be a smoke detector, temperature sensor or other fire detecting device, preferably a fusible link which is molten and broken at a temperature exceeding its melting point so that the slider 58 is released and hits the outer end of the rocking lever 56 and swings the inner end of the rocking lever 56 . Due to the projecting pin 561 extending into the sliding groove 521 , the bushing 52 is axially moved by the projecting pin 561 against so as to resist the disk spring 54 such that the bushing 52 is separated from the driven disc 141 . As a result, the coupling of the central shaft 12 and the first external shaft 14 is disconnected.
According to the present invention, the door operator can be modified into a failsafe door operator or a non-failsafe door operator easily. The most of components for the door operator can be applied to either the failsafe one or the non-failsafe one. Therefore, not only low manufacturing cost, fewer components and simplicity in production can be achieved, but also smaller inventory and easy replacement can be realized.
While the preferred embodiments have been described as above, it is noted that the preferred embodiments are not intended to restrict the scope of implementation of the present invention. Modifications and variations can be made without departing from the spirit and scope of the claims of the present invention.
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A door operator of the fireproof door comprises a force applying end for releasing the reel of a door curtain, and a loading end for sustaining the weight of the door curtain. The rotary shaft comprises an internal (central) shaft and a plurality of external shaft coupled to each other via a clutch mechanism. The force applying end and the loading end act on the internal shaft and the external shaft respectively. A torsion spring brake mechanism is provided to resist the potential energy of the loading end by varying the inner diameter of the torsion spring so as to constantly restrain the rotary shaft from rotating, or to release the rotary shaft when the brake mechanism is subjected to an external force from the force applying end.
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BACKGROUND OF THE INVENTION
This invention relates to a novel lubricant additive acting as a viscosity index improver (VII) and imparting enhanced fuel economy when employed in a lubricating oil composition.
The addition of oligomeric waxes or oils of polytetrafluoroethylene (PTFE) to lubricating oils is designed to reduce wear and friction on mechanized components of internal combustion engines. Less frequent replacement of worn or damaged engine components and greater gasoline efficiency are direct consequences. PTFE oils or waxes are not, however, soluble in any known lubricating oil.
Thus, it is an object of the present invention to provide a method of enhancing fuel economy in internal combustion engines by chemically incorporating oligomeric perfluoroaliphatic grafts onto ethylene-propylene copolymers or ethylene-propylene terpolymers. By incorporating these perfluoroaliphatic appendages, the ethylene-propylene copolymers or ethylene-propylene terpolymers are soluble in lubricating oils.
DISCLOSURE STATEMENT
U.S. 3,933,656 discloses a method of friction reduction between metal surfaces using a dispersion of polytetrafluoroethylene in lubricating oil.
U.S. 4,224,173 discloses a method of using polytetrafluoroethylene dispersions in lubricating oils to reduce friction and enhance fuel economy in internal combustion engines.
U.S. 4,284,518 discloses a method of using a colloidal dispersion of polytetrafluoroethylene as a wear resistant additive and fuel economizer during physical operation.
The disclosures in the foregoing patents which relate to VI improvers and fuel economizers for lubricating oils, namely U.S. Pat. Nos. 3,933,656, 4,224,173, and 4,284,518 are incorporated herein by reference.
SUMMARY OF THE INVENTION
The novel reaction product of the invention comprises a chemical modification of an ethylene-propylene copolymer or terpolymer. The terpolymer is typically a C 2 to C 10 alphaolefin and optionally a non-conjugated diene or triene. The novel lubricant of this invention comprises an oil of lubricating viscosity and an effective amount of the novel reaction product. The lubricating oil will be characterized as behaving as a viscosity index improver with enhanced fuel economy properties.
The invention comprises a chemical modification of an ethylene-propylene copolymer or terpolymer by chemically incorporating 2-isocyanoethylacrylate (I) onto the polymeric substrate and then
CH.sub.2 ═CH.sub.2 --CO--OCH.sub.2 CH.sub.2 --NCO (I)
(2-isocyanoethylacrylate)
further derivatizing using a perfluoroaliphatic alcohol.
Perfluoroaliphatic alcohols (II) that can be used in the derivation process are those materials that contain the perfluoroaliphatic unit and are represented by the following formula:
CF.sub.3 --(CF.sub.2)a--(CH.sub.2)b--OH (II)
(Perfluoroaliphatic alcohol)
in which the difluoro repeat unit, e.g., a, has a range of 1 to 20, and the hydrocarbon repeat unit, e.g., b, has a range of 2 to 10.
DETAILED DESCRIPTION OF THE INVENTION
The present method of enhancing fuel economy in internal combustion engines is by chemically incorporating oligomeric perfluoroaliphatic grafts onto ethylene-propylene copolymers or ethylene-propylene terpolymers.
This method offers distinct advantages over other methods that utilize perfluorooligomers in lubricating oils. Firstly, ethylene-propylene copolymers and terpolymers containing chemically grafted perfluorooligomers are completely soluble in a wide variety of solvents, including lubricating oils. This permits anti-friction properties to be imparted to the lubricating oils in a wide variety of temperatures and engine operating conditions. Secondly, the grafting methodology has application to polymers other then those with ethylene-propylene backbones.
The polymer or copolymer substrate employed as the novel additive of the invention may be prepared from ethylene or propylene or it may be prepared from ethylene and a higher olefin, which are typically C 3 to C 10 alpha-olefins.
More complex polymer substrates, often designated as interpolymers, may be prepared using a third component. The third component generally used to prepare an interpolymer substrate is a polyene monomer selected from non-conjugated dienes and trienes. This non-conjugated diene component typically has from 5 to 14 carbon atoms in the chain.
The diene monomer can include acyclic, cyclic, or bicyclic compounds. Representative dienes include 1,4-hexadiene. 1,4-cyclohexadiene, dicyclopentadiene, 5-ethylidene-2-norbornene, 5-methylene-2-norborene, 1,5-heptadiene and 1,6 octadiene. A mixture of more than one diene can be used in the preparation of the interpolymer. A preferred non-conjugated diene for preparing a terpolymer or interpolymer substrate is 1,4-hexadiene.
The triene component will have at least two nonconjugated double bonds, and up to about 30 carbon atoms in the chain. Typical trienes useful in preparing the interpolymer of the invention are 1-isopropylidene-3a,4,7,7a-tetrahydroindene, 1-isopropylidenedicyclopentadiene, dehydroisodicyclopentadiene, and 2-(2-methylene-4-methyl-3-pentenyl)-[2.2.1]bicyclo-5-heptene.
The polymerization reaction to form the polymer substrate is generally carried out in the presence of a catalyst in a solvent medium. The polymerization solvent may be any suitable inert organic solvent that is liquid under reactions conditions for solution polymerization of monoolefins which is generally conducted in the presence of a Ziegler-Natta type catalyst. Examples of satisfactory hydrocarbon solvents include straight chain paraffins having from 5-8 carbon atoms, with hexane being preferred. Aromatic hydrocarbon, preferably aromatic hydrocarbon having a single benzene nucleus, such as benzene, toluene and the like or saturated cyclic hydrocarbons having boiling point ranges approximating those of the straight chain paraffinic hydrocarbons and aromatic hydrocarbons described above, are particularly suitable. The solvent selected may be a mixture of one or more of the foregoing hydrocarbons. It is desirable that the solvent be free of substances that will interfere with the Ziegler-Natta polymerization process.
In a typical preparation of the polymer substrate, hexane is first introduced into a reactor and the temperature in the reactor is raised moderately to about 30° C. Dry propylene is fed to the reactor until the pressure reaches about 40-45 inches of mercury. The pressure is then increased to about 60 inches of mercury and dry ethylene and 5-ethylidene-2-norbornene are fed to the reactor. The monomer feeds are stopped and a mixture of aluminum sesquichloride and vanadium oxytrichloride are added to initiate the polymerization reaction. Completion of the polymerization reaction is indicated by a pressure drop in the reactor.
Ethylene-propylene copolymers or ethylene-propylene and higher alpha monoolefin terpolymers may consist of from about 15 to 80 mole percent ethylene and from about 20 to 85 mole percent propylene or higher monoolefin with the preferred mole ratios being from about 50 to 80 mole percent ethylene and from about 20 to 50 mole percent of a C 3 to C 10 alpha monoolefin with the most preferred proportions being from 55 to 80 mole percent ethylene and 20 to 75 mole percent propylene, and having a number average molecular weight of about 5,000 to 500,000.
Terpolymer variations of the foregoing polymers may contain from about 0.1 to 10 mole percent of a non-conjugated diene or triene.
The polymer substrate, that is the ethylene-propylene copolymer or terpolymer is an oil-soluble, substantially linear, rubbery material having a number average molecular weight of about 5,000 to 500,000 with a preferred number average molecular weight of about 25,000 to 250,000 and a most preferred range of about 50,000 to 150,000.
The terms polymer and copolymer are used generically to encompass ethylene-propylene copolymers, terpolymers or interpolymers. These materials may contain minor amounts of other olefinic monomers so long as their basic characteristics are not materially changed.
The 2-isocyanoethylacrylate may be grafted onto the polymer backbone in a number of ways. It may be grafted onto the backbone by a thermal process known as the "ene" process or by grafting in solution using a free radical initiator. The free-radical induced grafting of substituted acryamides in non-polar solvents containing 5-9 carbon atoms or monoaromatic solvents, benzene being the preferred method. It is carried out in an inert atmosphere at an elevated temperature in the range of about 100° C. to 250° C., preferably 120° C. to 190° C., and more preferably at 150° C. to 180° C., e.g. above 160° C., in a hydrocarbon solvent, preferably a mineral lubricating oil solution, containing, e.g., 1 to 50 weight percent polymer, preferably 20 to 40 weight percent.
The free radical initiators which may be used are peroxides, hydroperoxides, and azo compounds and preferably those which have a boiling point greater than 100° C. and decompose thermally within the grafting temperature range to provide free radicals. Representative of these free radical initiators are dicumylperoxide and 2,5-dimethyl-hex-3-yne-2,5-bis tertiary-butyl peroxide. The initiator is used in an amount of between 0.005% and about 2% by weight based on the weight of the reaction mixture solution. The grafting is preferably carried out in an inert atmosphere, for instance nitrogen. The resulting polymer is characterized as having pendant 2-isocyanoethylacrylate functions within its structure.
The polymer intermediate possessing a pendant 2-isocyanoethylacrylate function is reacted with perfluoroaliphatic alcohols represented by the following formula:
CF.sub.3 --(CF.sub.2)a--(CH2)b--OH (III)
in which the perfluoro repeat unit, e.g., a, varies from 1 to 20 and the hydrocarbon repeat unit, e.g., b, varies from 2 to 10.
The perfluoroaliphatic alcohol may be a perfluoroaliphatic-1,1,2,2-tetra-H-ethyl alcohol having a molecular weight range of about 440 to about 525, and preferably an average molecular weight of about 475.
Examples of perfluoroaliphatic alcohols are those materials where the average perfluoroalkyl chain length is 7.3, or 8.2, or 9.0 while the hydrocarbon repeat unit may vary from 2 to 10, 2 being the preferred number. Perfluoroaliphatic alcohols with average perfluoroalkyl chain lengths of 7.3, 8.2, and 9.0 consist of mixtures of perfluoroalkyl chains, the weight percentages of which are described in Table I. They are available commerically under the tradenames of Zonyl BA-L, ZONYL BA, and ZONYL BA-N, respectively, and are available from E. I. DuPont deNemours and Co of Wilmington, Delaware.
In Table I, below, the weight percentages are provided of perfluoroalkyl chains present in perfluoroaliphatic alcohols.
TABLE I______________________________________Fluoroalkane ZONYL BA-L ZONYL BA ZONYLBA-NChain (wt %) (wt %) (wt %)______________________________________C4F9 4 max 4 max 0C6F13 50 3 35 3 6 maxC8F17 29 2 30 3 50 3C10F21 11 2 17 2 29 2C12F25 4 1 8 1 11 2C14F29 2 max 6 max 4 maxand higher______________________________________
The reaction between the polymer substrate containing pendant 2-isocyanoethylacrylate and the prescribed perfluoroaliphatic alcohol is conducted by heating a solution of the polymer intermediate under inert conditions and then adding the perfluoroaliphatic alcohol with stirring to effect the reaction. It is convenient to employ an oil solution of the polymer substrate heated to 140° to 175° C. while maintaining the solution under a nitrogen blanket. One of the perfluoroaliphatic alcohols with an average perfluoroalkyl repeat unit of 7.3, 8.2, or 9.0 is added to this solution and the reaction is effected under these conditions.
The following examples illustrate the preparation of the novel reaction product additive of this invention.
EXAMPLE I
Preparation of OCP-g-2-isocyanoethylacrylate
Two hundred grams of polymeric substrate consisting of about 60 mole percent ethylene and 40 mole percent propylene and having a number average molecular weight of 80,000 was dissolved in 1440 grams of solvent neutral oil at 160° C. using a mechanical stirrer while the mixture was maintained under a blanket of nitrogen. After the rubber was dissolved, the mixture was heated an additional hour at 160° C. Eleven grams of 2-isocyanoethylacrylate are dissolved in 10 grams of solvent neutral oil and added to the above mixture along with 2.5 grams of dicumyl peroxide also dissolved in 10 grams of oil. The mixture reacted for 2.5 hours at 160° C. then filtered through a 200 mesh screen.
EXAMPLE II
Reaction of OCP-g-2-isocyanoethylacrylate with perfluoroaliphatic alcohol
Twenty six grams of the aforementioned graft copolymer was dissolved in 174 grams of solvent neutral oil at 160° C. using mechanical stirring under a nitrogen blanket. Perfluoroaliphatic alcohol (3.4 grams) with a perfluoroaliphatic repeat unit of 9.0 was added neat to the mixture and the reaction heated for an additional hour under the aforementioned conditions. The mixture was then cooled to 120° C. and filtered through a 200 mesh filter.
EXAMPLE III
Reaction of OCP-g-2-isocyanoethylacrylate with perfluoroaliphatic alcohol
2.8g of perfluoroaliphatic alcohol with a perfluoroaliphatic repeat unit of 8.2 may be substituted in the aforementioned procedure.
EXAMPLE IV
Reaction of OCP-g-2-isocyanoethylacrylate with perfluoroaliphatic alcohol
2.2g of perfluoroaliphatic alcohol with a perfluoroaliphatic repeat unit of 7.3 may be substituted in the aforementioned procedure.
The novel graft and derivatized polymer of the invention is useful as an additive for lubricating oils that is designed to enhance the fuel economy in internal combustion engines. It can be employed in a variety of oils of lubricating viscosity including natural and synthetic base oils and mixtures thereof. The novel additives can be employed in crankcase lubricating oils for spark-ignited and compression-ignited internal combustion engines. The compositions can also be used in gas engines, or turbines, automatic transmission fluids, gear lubricants, metal-working lubricants, hydraulic fluids, and other lubricating oil and grease compositions. Their use in motor fuel compositions is also contemplated.
The base oil may be a natural oil including liquid petroleum oils and solvent-treated or acid-treated mineral lubricating oils of the paraffinic, naphthenic and mixed paraffinic-naphthenic types.
In general, the lubricating oil composition of the invention will contain the novel reaction product in a concentration ranging from about 0.1 to 30 weight percent. A preferred concentration range for the additive is from about 1 to 15 weight percent based on the total weight of the oil composition.
Oil concentrates of the additive may contain from about 1 to 50 weight percent of the additive reaction product in a carrier or diluent oil of lubricating oil viscosity.
The novel product of this reaction may be employed in lubricating oil compositions together with conventional lubricant additives. Such additives may include dispersants, detergents, anti-oxidants, pour point depressants and the like.
The novel product of this invention was tested for its effectiveness as a fuel economy agent in a fully formulated lubricating oil composition in a 12.5 wt% concentrate. Table II provides a description of the two components used to prepare this concentrate.
TABLE II______________________________________Component Parts by Weight______________________________________Solvent Neutral Oil A 100Product 12.50______________________________________
Oil A has a sp. gr. 60/60° F. of 0.858-0.868; Vis. @ 100° F. of 123-133 cPs; Pour-Point is 0° F.
Energy conserving properties of the novel additive were evaluated using the ASTM Sequence VI Gasoline Fuel Efficient Oil Test. This test evaluates the energy conserving propertities of oil formulations and provides an Equivalent Fuel Economy Index (EFEI) for the energy conserving propertities of the formulation. The higher the EFEI the greater the energy conserving propertities of the formulation. Oil formulations containing the experimental polymer were prepared without friction modifiers; a typical formulation is provided in Table III.
TABLE III______________________________________Material Wt Percent______________________________________Experimental Base Blend 85.0Texaco SNO-100 5.0Texaco - 7200 A 9.0Experimental Friction 1.0(12 wt % concentrate)______________________________________
The Experimental Base Blend consisted of Base oil and a DI package. The components of the DI package are provided below in Table IV.
TABLE IV______________________________________DI PACKAGE USED IN EXPERIMENTAL BASE BLENDComponent Parts by Weight______________________________________4,4'dinonyldiphenylamine .39Overbased magnesium sulfonate 1.50Silicone anifoamant 150 PPM______________________________________
Two other perfluoaoaliphatic monomers were chemically grafted to the OCP rubber and evaluated by the Sequence VI Test. Each material contained approximately the same perfluoroaliphatic repeat unit but did not contain a urethane bond. This was performed to underscore the importance of incorporating pendant perfluoroaliphatic groups using a urethane linkage. Sequence VI Testing was also performed using mixtures of perfluoroaliphatic alcohols mixtures containing perfluoroaliphatic alcohols and OCP rubber. This was performed to demonstrate that independent of the chemical moiety used to graft the perfluoroaliphatic alcohol, only chemical grafting can ensure enhanced fuel economy. Moreover, the mixture containing the perfluoroaliphatic alcohol dramatically demonstrated the inefficiency of perfluorooligomeric dispersions. In Table V, below, the results are summarized of Sequence VI Testing using experimental friction modifiers.
TABLE IV______________________________________ Equivalent Fuel Economy IndexPolymer Additive (%)______________________________________Unmodified ethylene-propylene copolymer 2.90Perfluoroaliphatic urethane graft 4.22Perfluoroaliphatic alkene graft 2.89Perfluoroaliphatic alcohol mixture 0.90______________________________________
The results from the Sequence VI Test show that enhanced fuel economy is obtained by a unique combination of perfluoroaliphatic groups grafted to ethylene-propylene copolymers using a urethane bond.
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A polymeric lubricating oil additive containing pendant perfluoroaliphatic urethane units that behaves as a VI Improver and a fuel economy enhancer when added to lubricating oil compositions. The polymeric substrate may be a copolymer of 15-85 mole % ethylene and propylene or a terpolymer of 15-85 mole % ethylene, propylene, and 20-80 mole % of a non-conjugated diene or triene (C 3 -C 10 ) alpha olefin. The copolymer or terpolymer substrate has a molecular weight range of about 5,000 to about 500,000. A graft copolymer or terpolymer containing pendant isocyanate groups is prepared by reacting the ethylene propylene co- or terpolymer with an acrylating agent. Post-reacting the copolymer or terpolymer containing the pendant isocyanate group with a perfluoroaliphatic alcohol generates the additive.
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FIELD OF THE INVENTION
[0001] The invention relates to methods for acute treatment of trauma victims, including the prevention of, or minimizing severity of, late complications in trauma patients.
BACKGROUND OF THE INVENTION
[0002] Haemostasis is a complex physiological process which ultimately results in the arrest of bleeding. This is dependent on the proper function of three main components: blood vessels (especially the endothelial lining), coagulation factors, and platelets. Once a haemostatic plug is formed, the timely activation of the fibrinolytic system is equally important to prevent further unnecessary haemostatic activation. Any malfunction of this system (due to a reduced number, or molecular dysfunction, of the haemostatic components or increased activation of the fibrinolytic components) may lead to clinical bleeding such as, e.g., haemorrhagic diathesis of varying severity.
[0003] In most physiological situations, haemostasis is triggered by the interaction of circulating activated coagulation factor VII (FVIIa) with tissue factor (TF) subsequent to exposure of TF at the site of an injury. Endogenous FVIIa becomes proteolytically active only after forming a complex with TF. Normally, TF is expressed in the deep layers of the vessel wall and is exposed following injury. This ensures a highly localized activation of coagulation and prevents disseminated coagulation. TF also seems to exist in a non-active form, so-called encrypted TF. The regulation of encrypted versus active TF is still unknown.
[0004] TF has in recent years been demonstrated in the circulating blood in a variety of situations such as trauma, sepsis, abdominal surgery. These studies used immunochemically-based methods for the determination of TF (ELISA). Such methods determine both active and inactive TF as well as TF in complex with any other proteins, (such as FVIIa, TFPI, etc.) and thus do not indicate whether the TF found is active or not. The respective subjects were undergoing surgery for idiopathic thoracic scoliosis, an extensive surgical trauma associated with significant tissue injury. Another study failed to demonstrate any TF in the circulation following major orthopaedic surgery (total hip replacement and knee replacement) known to be associated with a high frequency of postoperative deep venous thrombosis (DVT).
[0005] Activated recombinant human factor VII (rFVIIa) is indicated for the treatment of bleeding episodes in haemophilia A or B subjects with inhibitors to Factor VIII or Factor IX. When given in high (pharmacological) doses, rFVIIa can bind independently of TF to activated platelets and initiate local thrombin generation which is important for the formation of the initial haemostatic plug.
[0006] Uncontrolled bleeding is the major cause of death (39%) in civilian trauma victims. Sixty-five percent (65%) of deaths occur after admission to the hospital and exsanguination is responsible for between 15-40% of hospital deaths in trauma subjects. In subjects with complex liver injuries, the mortality exceeds 40%. There is a correlation between transfusion with blood products and mortality. Many critically ill trauma subjects have profound coagulopathy which correlates to the severity of injury.
[0007] The uncontrolled life threatening bleeding and acquired coagulopathy secondary to transfusion, hypothermia and other related causes faced by these subjects may further lead to so-called late complications including pulmonary embolism, Disseminated Intravascular Coagulation (DIC), Acute Myocardial infarction, Cerebral Thrombosis, Multiple organ Failure (MOF), systemic inflammatory response syndrome (SIRS), and Acute Respiratory Distress Syndrome (ARDS), which complications contribute significantly to later deaths of trauma victims.
[0008] Thus, there is a need in the art for improved methods and compositions for acute treatment of trauma, as well as for prevention and attenuation of late complications that result from trauma itself and from conventional modalities that are used to treat trauma victims.
SUMMARY OF THE INVENTION
[0009] The invention provides the use of Factor VIIa or a Factor VIIa equivalent for the manufacture of a medicament for treatment of trauma. Typical patients for whom the medicament is used are those suffering from coagulopathic bleedings, including, without limitation, patients who have experienced blunt or penetrating trauma.
[0010] The invention also provides methods for treating trauma, which are carried out by administering to a patient an effective amount for said preventing or attenuating of Factor VIIa or a Factor VIIa equivalent. Typical patients have experienced blunt trauma or penetrating trauma.
[0011] In some embodiments, the initial administering step is carried out within 5 hours of the occurrence of the traumatic injury. In some embodiments, the effective amount comprises at least about 150 μg/kg of Factor VIIa or a corresponding amount of a Factor VIIa equivalent. In some embodiments, a first amount of at least about 200 ug/kg Factor VIIa or a corresponding amount of a Factor VIIa equivalent is administered at the start of treatment, and a second amount of about 100 μg/kg of Factor VIIa or a corresponding amount of a Factor VIIa equivalent is administered to the patient one or more hours after the start of treatment. In some embodiments, a third amount of about 100 μg/kg of Factor VIIa or a corresponding Factor VIIa equivalent is administered at a later time, such as, e.g., at three hours after the start of treatment.
[0012] In some embodiments, the method further comprises administering to the patient a second coagulation agent in an amount that augments the treatment by said Factor VIIa or Factor VIIa equivalent. Preferably, the second coagulation agent is a coagulation factor (including, without limitation, Factor VIII, Factor IX, Factor V, Factor XI, Factor XIII, and any combination thereof) or an antifibrinolytic agent (including, without limitation, PAI-1, aprotinin, ε-aminocaproic acid, tranexamic acid, or any combination thereof).
[0013] The invention also provides methods for treating trauma in a majority of trauma patients, which are carried out by: (i) administering to a group of trauma patients an amount effective for treatment of Factor VIIa or a Factor VIIa equivalent; and (ii) observing a reduction in of trauma among the group of patients who received Factor VIIa or a Factor VIIa equivalent relative to the frequency of occurrence of said late complications that would have been expected in the same group of patients who had not received said Factor VIIa or Factor VIIa equivalent.
LIST OF FIGURES
[0014] FIG. 1 shows the distribution of RBC requirements within the 48-hour observation period following first dose of trial product.
[0015] FIG. 2 shows the percentage of patients alive at 48 hours receiving >12 units of RBC within 48 hours of first dose, which equals >20 units of RBC inclusive of the 8 pre-dose units
[0016] FIG. 3 shows survival curves for blunt and penetrating trauma populations.
DETAILED DESCRIPTION OF THE INVENTION
[0017] The present invention provides methods and compositions that can be used advantageously to treat trauma patients. The methods are carried out by administering to a trauma patient Factor VIIa or a Factor VIIa equivalent, in a manner that is effective for treatment. A manner effective for treatment may comprise administering a predetermined amount of Factor VIIa or a Factor VIIa equivalent, and/or utilizing a particular dosage regimen, formulation, mode of administration, combination with other treatments, and the like. The efficacy of the methods of the invention in treating trauma may be assessed using one or more conventionally used parameters of the immediate consequences of injury and/or late complications (see below). Immediate consequences include, e.g., blood loss and symptoms of shock; while late complications, include, without limitation, Pulmonary embolism (PE), Acute Respiratory Distress Syndrome (ARDS), Disseminated Intravascular Coagulation (DIC), Acute Myocardial Infarction (AMI), Cerebral Thrombosis (CT), Systemic Inflammatory Response Syndrome (SIRS), infections, Multiple Organ Failure (MOF), and Acute Lung Injury (ALI), including death caused by one or more of these syndromes.
[0000] Patient Selection:
[0018] Patients who may benefit by use of the methods of the present invention include, without limitation, patients who have suffered from blunt trauma and/or penetrating trauma. Blunt trauma includes blunt injuries, such as, e.g., those caused by traffic accidents or falls, which could result in one or more of liver injuries, multiple fractures, brain contusions, as well as lacerations of the spleen, lungs, or diaphragm. Blunt trauma is generally accompanied by more extensive tissue damage as compared to penetrating trauma and, consequently, more small vessel bleeding. Penetrating trauma includes penetrating injuries, such as, e.g., those caused by gun shot wounds or stab wounds, which could result in penetration of the inferior vena cava, liver damage, lung injury, injury to prostate, urinary bladder, thorax and liver lacerations, and wounds to the pelvis or chest.
[0019] Trauma may cause injury to, and subsequent bleeding from, both larger and smaller vessels. Excessive or massive bleeding in most trauma cases presents a combination of bleeding from vessels needing surgical treatment (“surgical bleeding”) and diffuse uncontrolled bleeding from small vessels (“coagulopathic bleeding”). Furthermore, trauma subjects who receive massive transfusions often suffer from coagulopathy and continue to bleed profusely despite intervention with surgical procedures, packing, and embolization of larger vessels.
[0020] Bleeding refers to extravasation of blood from any component of the circulatory system and encompasses any bleeding (including, without limitation, excessive, uncontrolled bleeding, i.e., haemorrhaging) in connection with trauma. In one series of embodiments, the excessive bleeding is caused by blunt injury; in another it is caused by penetrating injury. In one series of embodiment, the injury(ies) is/are to the liver, spleen, lungs, diaphragm, head, including the brain. In another series of embodiments, the injury(ies) is/are to the inferior vena cava, liver damage, lung injury, injury to prostate, urinary bladder, thorax and liver lacerations, pelvis or chest, or head, including the brain.
[0021] Coagulopathy in trauma is multifactorial, encompassing coagulation abnormalities resembling DIC, caused by systemic activation of coagulation and fibrinolysis; excessive fibrinolysis, which can be evident on the first day in some trauma subjects; and dilutional coagulopathy, which is caused by excessive fluid administration. Some fluids such as hydroxyethyl starch (HES) preparations may directly compromise coagulation. Massive transfusion syndrome results in depletion of coagulation factors and impairment of platelet function. Hypothermia causes a slower enzyme activity of the coagulation cascade and dysfunctional platelets. Metabolic abnormalities, such as acidosis, also compromise coagulation especially when associated with hypothermia.
[0022] Non-limiting examples of patients in need of treatment according to the invention include those who exhibit one or more of the following:
Coagulation abnormalities resembling DIC, caused by systemic activation of coagulation and fibrinolysis Excessive fibrinolysis Dilutional coagulopathy caused by excessive fluid treatment, including, without limitation, a limited number of platelets and/or an impaired platelet function compared to the platelet count and platelet activity of normal pooled blood Receipt of hydroxyethyl starch (HES) preparations Hypothermia, a including having body temperature below about 37° C., such as, e.g., below about 36° C., below about 35° C., or below about 34° C. At least one indication of metabolic abnormalities, including, without limitation, acidosis having a blood pH below about 7.5, such as, e.g., below about 7.4, below about 7.3, below about 7.2, or below about 7.1.
[0029] The methods of the present invention can be applied advantageously to any patient who has suffered blunt and/or penetrating trauma that, if left untreated, would result in a significant loss of blood, such as, e.g., over 10% of the patient's total blood volume (loss of over 40% of blood volume is immediately life-threatening.) A normal blood volume represents about 7% of an adult's ideal body weight and about 8-9% of a child's ideal body weight.
[0030] In one series of embodiments, patients treated according to the invention are those who have received less than about 10 units of whole blood (WB), packed red blood cells (pRBC), or fresh frozen plasma (FFP) between the time of their traumatic injury and the time of administration of Factor VIIa or Factor VIIa equivalent. A unit of WB typically contains about 450 ml blood and 63 ml of conventional anticoagulant/preservative (having a haematocrit of 36-44%). A unit of pRBC typically contains 200-250 ml of red blood cells, plasma, and conventional anticoagulant/preservative (having a haematocrit of 70-80%). In other embodiments, patients treated according to the invention have received less than about 8 units of WB, pRBC, or FFP, such as, e.g., less than about 5 units, or less than about 2 units, or have not received any blood products and/or volume replacement products prior to administration of Factor VIIa or Factor VIIa equivalent.
[0031] In one series of embodiments, patients treated according to the invention do not suffer from a bleeding disorder, whether congenital or acquired, such as, e.g., Haemophilia A, B. or C.
[0032] In different embodiments of the invention, patients may be excluded from treatment if they have received transfusion of 10 units or more of PRBC, such as, e.g., more than 15, 20, 25, or 30 units, or if they have been diagnosed with a congenital bleeding disorder.
[0000] Factor VIIa and Factor VIIa Equivalents:
[0033] In practicing the present invention, any Factor VIIa or Factor VIIa equivalent may be used that is effective in treating trauma. In some embodiments, the Factor VIIa is human Factor VIIa, as disclosed, e.g., in U.S. Pat. No. 4,784,950 (wild-type Factor VII). The term “Factor VII” is intended to encompass Factor VII polypeptides in their uncleaved (zymogen) form, as well as those that have been proteolytically processed to yield their respective bioactive forms, which may be designated Factor VIIa. Typically, Factor VII is cleaved between residues 152 and 153 to yield Factor VIIa.
[0034] Factor VIIa equivalents include, without limitation, Factor VII polypeptides that have either been chemically modified relative to human Factor VIIa and/or contain one or more amino acid sequence alterations relative to human Factor VIIa. Such equivalents may exhibit different properties relative to human Factor VIIa, including stability, phospholipid binding, altered specific activity, and the like.
[0035] In one series of embodiments, a Factor VIIa equivalent includes polypeptides that exhibit at least about 10%, preferably at least about 30%, more preferably at least about 50%, and most preferably at least about 70%, of the specific biological activity of human Factor VIIa. For purposes of the invention, Factor VIIa biological activity may be quantified by measuring the ability of a preparation to promote blood clotting using Factor VII-deficient plasma and thromboplastin, as described, e.g., in U.S. Pat. No. 5,997,864. In this assay, biological activity is expressed as the reduction in clotting time relative to a control sample and is converted to “Factor VII units” by comparison with a pooled human serum standard containing 1 unit/ml Factor VII activity. Alternatively, Factor VIIa biological activity may be quantified by (i) measuring the ability of Factor VIIa or a Factor VIIa equivalent to produce of Factor Xa in a system comprising TF embedded in a lipid membrane and Factor X. (Persson et al., J. Biol. Chem. 272:19919-19924, 1997); (ii) measuring Factor X hydrolysis in an aqueous system (see, Example 5 below); (iii) measuring the physical binding of Factor VIIa or a Factor VIIa equivalent to TF using an instrument based on surface plasmon resonance (Persson, FEBS Letts. 413:359-363, 1997) and (iv) measuring hydrolysis of a synthetic substrate by Factor VIIa and/or a Factor VIIa equivalent.
[0036] Examples of factor VII equivalents include, without limitation, wild-type Factor VII, L305V-FVII, L305V/M306D/D309S-FVII, L305I-FVII, L305T-FVII, F374P-FVII, V158T/M298Q-FVII, V158D/E296V/M298Q-FVII, K337A-FVII, M298Q-FVII, V158D/M298Q-FVII, L305V/K337A-FVII, V158D/E296V/M298Q/L305V-FVII, V158D/E296V/M298Q/K337A-FVII, V158D/E296V/M298Q/L305V/K337A-FVII, K157A-FVII, E296V-FVII, E296V/M298Q-FVII, V158D/E296V-FVII, V158D/M298K-FVII, and S336G-FVII, L305V/K337A-FVII, L305V/V158D-FVII, L305V/E296V-FVII, L305V/M298Q-FVII, L305V/V158T-FVII, L305V/K337A/V158T-FVII, L305V/K337A/M298Q-FVII, L305V/K337A/E296V-FVII, L305V/K337A/V158D-FVII, L305V/V158D/M298Q-FVII, L305V/V158D/E296V-FVII, L305V/V158T/M298Q-FVII, L305V/V158T/E296V-FVII, L305V/E296V/M298Q-FVII, L305V/V158D/E296V/M298Q-FVII, L305V/V158T/E296V/M298Q-FVII, L305V/V158T/K337A/M298Q-FVII, L305V/V158T/E296V/K337A-FVII, L305V/V158D/K337A/M298Q-FVII, L305V/V158D/E296V/K337A-FVII, L305V/V158D/E296V/M298Q/K337A-FVII, L305V/V158T/E296V/M298Q/K337A-FVII, S314E/K316H-FVII, S314E/K316Q-FVII, S314E/L305V-FVII, S314E/K337A-FVII, S314E/V158D-FVII, S314E/E296V-FVII, S314E/M298Q-FVII, S314E/V158T-FVII, K316H/L305V-FVII, K316H/K337A-FVII, K316H/V158D-FVII, K316H/E296V-FVII, K316H/M298Q-FVII, K316H/V158T-FVII, K316Q/L305V-FVII, K316Q/K337A-FVII, K316Q/V158D-FVII, K316Q/E296V-FVII, K316Q/M298Q-FVII, K316Q/V158T-FVII, S314E/L305V/K337A-FVII, S314E/L305V/V158D-FVII, S314E/L305V/E296V-FVII, S314E/L305V/M298Q-FVII, S314E/L305V/V158T-FVII, S314E/L305V/K337A/V158T-FVII, S314E/L305V/K337A/M298Q-FVII, S314E/L305V/K337A/E296V-FVII, S314E/L305V/K337A/V158D-FVII, S314E/L305V/V158D/M 298Q-FVII, S314E/L305V/V158D/E296V-FVII, S314E/L305V/V158T/M298Q-FVII, S314E/L305V/V158T/E296V-FVII, S314E/L305V/E296V/M298Q-FVII, S314E/L305V/V158D/E296V/M298Q-FVII, S314E/L305V/V158T/E296V/M298Q-FVII, S314E/L305V/V158T/K337A/M298Q-FVII, S314E/L305V/V158T/E296V/K337A-FVII, S314E/L305V/V158D/K337A/M298Q-FVII, S314E/L305V/V158D/E296V/K337A -FVII, S314E/L305V/V158D/E296V/M298Q/K337A-FVII, S314E/L305V/V158T/E296V/M298Q/K337A-FVII, K316H/L305V/K337A-FVII, K316H/L305V/V158D-FVII, K316H/L305V/E296V-FVII, K316H/L305V/M298Q-FVII, K316H/L305V/V158T-FVII, K316H/L305V/K337A/V158T-FVII, K316H/L305V/K337A/M298Q-FVII, K316H/L305V/K337A/E296V-FVII, K316H/L305V/K337A/V158D-FVII, K316H/L305V/V158D/M298Q-FVII, K316H/L305V/V158D/E296V-FVII, K316H/L305V/V158T/M298Q-FVII, K316H/L305V/V158T/E296V-FVII, K316H/L305V/E296V/M298Q-FVII, K316H/L305V/V158D/E296V/M298Q-FVII, K316H/L305V/V158T/E296V/M298Q-FVII, K316H/L305V/V158T/K337A/M298Q-FVII, K316H/L305V/V158T/E296V/K337A-FVII, K316H/L305V/V158D/K337A/M298Q-FVII, K316H/L305V/V158D/E296V/K337A -FVII, K316H/L305V/V158D/E296V/M298Q/K337A-FVII, K316H/L305V/V158T/E296V/M298Q/K337A-FVII, K316Q/L305V/K337A-FVII, K316Q/L305V/V158D-FVII, K316Q/L305V/E296V-FVII, K316Q/L305V/M298Q-FVII, K316Q/L305V/V158T-FVII, K316Q/L305V/K337A/V158T-FVII, K316Q/L305V/K337A/M298Q-FVII, K316Q/L305V/K337A/E296V-FVII, K316Q/L305V/K337A/V158D-FVII, K316Q/L305V/V158D/M298Q-FVII, K316Q/L305V/V158D/E296V-FVII, K316Q/L305V/V158T/M298Q-FVII, K316Q/L305V/V158T/E296V-FVII, K316Q/L305V/E296V/M298Q-FVII, K316Q/L305V/V158D/E296V/M298Q-FVII, K316Q/L305V/V158T/E296V/M298Q-FVII, K316Q/L305V/V158T/K337A/M298Q-FVII, K316Q/L305V/V158T/E296V/K337A-FVII, K316Q/L305V/V158D/K337A/M298Q-FVII, K316Q/L305V/V158D/E296V/K337A-FVII, K316Q/L305V/V158D/E296V/M298Q/K337A-FVII, and K316Q/L305V/V158T/E296V/M298Q/K337A-FVII.
[0000] In some embodiments, the factor VII equivalent is V158D/E296V/M298Q-FVII.
[0000] Preparations and Formulations:
[0037] The present invention encompasses therapeutic administration of Factor VIIa or Factor VIIa equivalents, which is achieved using formulations that comprise Factor VIIa preparations. As used herein, a “Factor VII preparation” refers to a plurality of Factor VIIa polypeptides or Factor VIIa equivalent polypeptides, including variants and chemically modified forms, that have been separated from the cell in which they were synthesized, whether a cell of origin or a recombinant cell that has been programmed to synthesize Factor VIIa or a Factor VIIa equivalent.
[0038] Separation of polypeptides from their cell of origin may be achieved by any method known in the art, including, without limitation, removal of cell culture medium containing the desired product from an adherent cell culture; centrifugation or filtration to remove non-adherent cells; and the like.
[0039] Optionally, Factor VII polypeptides may be further purified. Purification may be achieved using any method known in the art, including, without limitation, affinity chromatography, such as, e.g., on an anti-Factor VII antibody column (see, e.g., Wakabayashi et al., J. Biol. Chem. 261:11097, 1986; and Thim et al., Biochem. 27:7785, 1988); hydrophobic interaction chromatography; ion-exchange chromatography; size exclusion chromatography; electrophoretic procedures (e.g., preparative isoelectric focusing (IEF), differential solubility (e.g., ammonium sulfate precipitation), or extraction and the like. See, generally, Scopes, Protein Purification, Springer-Verlag, New York, 1982; and Protein Purification, J.-C. Janson and Lars Ryden, editors, VCH Publishers, New York, 1989. Following purification, the preparation preferably contains less than about 10% by weight, more preferably less than about 5% and most preferably less than about 1%, of non-Factor VII proteins derived from the host cell.
[0040] Factor VII and Factor VII-related polypeptides may be activated by proteolytic cleavage, using Factor XIIa or other proteases having trypsin-like specificity, such as, e.g., Factor IXa, kallikrein, Factor Xa, and thrombin. See, e.g., Osterud et al., Biochem. 11:2853 (1972); Thomas, U.S. Pat. No. 4,456,591; and Hedner et al., J. Clin. Invest. 71:1836 (1983). Alternatively, Factor VII may be activated by passing it through an ion-exchange chromatography column, such as Mono Q® (Pharmacia) or the like. The resulting activated Factor VII may then be formulated and administered as described below.
[0041] Pharmaceutical compositions or formulations for use in the present invention comprise a Factor VIIa preparation in combination with, preferably dissolved in, a pharmaceutically acceptable carrier, preferably an aqueous carrier or diluent. A variety of aqueous carriers may be used, such as water, buffered water, 0.4% saline, 0.3% glycine and the like. The preparations of the invention can also be formulated into liposome preparations for delivery or targeting to the sites of injury. Liposome preparations are generally described in, e.g., U.S. Pat. Nos. 4,837,028, 4,501,728, and 4,975,282. The compositions may be sterilised by conventional, well-known sterilisation techniques. The resulting aqueous solutions may be packaged for use or filtered under aseptic conditions and lyophilised, the lyophilised preparation being combined with a sterile aqueous solution prior to administration.
[0042] The compositions may contain pharmaceutically acceptable auxiliary substances or adjuvants, including, without limitation, pH adjusting and buffering agents and/or tonicity adjusting agents, such as, for example, sodium acetate, sodium lactate, sodium chloride, potassium chloride, calcium chloride, etc.
[0000] Treatment Regimen:
[0043] In practicing the present invention, Factor VIIa or the Factor VIIa equivalent may be administered to a patient as a single dose comprising a single-dose-effective amount for treating trauma, or in a staged series of doses which together comprise an effective amount for treating trauma. An effective amount of Factor VIIa or the Factor VIIa equivalent (see below) refers to the amount of Factor VIIa or equivalent which, when administered in a single dose or in the aggregate of multiple doses, or as part of any other type of defined treatment regimen, produces a measurable improvement in at least one clinical parameter associated with trauma (see below). When Factor VIIa equivalents are administered, an effective amount may be determined by comparing the coagulant activity of the Factor VIIa equivalent with that of Factor VIIa and adjusting the amount to be administered proportionately to the predetermined effective dose of Factor VIIa.
[0044] Administration of Factor VIIa or a Factor VIIa equivalent according to the present invention is preferably initiated within about 6 hours after occurrence of the traumatic injury, such as, e.g., within about 4 hours, within about 2 hours, or within about 1 hour.
[0045] Administration of a single dose refers to administration of an entire dose of Factor VIIa or the Factor VIIa equivalent as a bolus over a period of less than about 5 minutes. In some embodiments, the administration occurs over a period of less than about 2.5 minutes, and, in some, over less than about 1 min. Typically, a single-dose effective amount comprises at least about 40 ug/kg human Factor VIIa or a corresponding amount of a Factor VIIa equivalent, such as, at least about 50 ug/kg, 75 ug/kg, or 90 ug/kg, or at least 150 ug/kg Factor VIIa.
[0046] In some embodiments, following administration of a single dose of Factor VIIa or a Factor VIIa equivalent according to the invention, the patient receives no further Factor VIIa or Factor VIIa equivalent for an interval of at least about 15 minutes. In some embodiments the post-administration interval is at least about 30 minutes, such as at least about 45 minutes, at least about 1 hour, at least about 1.5 hours, or at least about 2 hours.
[0047] In other embodiments, the patient receives Factor VIIa or Factor VIIa equivalent according to the following regimen: (i) The patient receives a first amount of Factor VIIa or Factor VIIa equivalent comprising at least about 40 ug/kg; (ii) after a period of at least about 30 minutes, a second amount of Factor VIIa or Factor VIIa equivalent is administered, the amount comprising at least about 40 ug/kg; and (iii) after a period of at least about 30 minutes from administration of the second dose, a third amount of Factor VIIa or Factor VIIa equivalent is administered, the amount comprising at least about 40 ug/kg. After a period of at least about 30 minutes following the administration of the third amount, the patient may then receive a further (fourth) amount of Factor VIIa or Factor VIIa equivalent comprising at least about 40 ug/kg.
[0048] In other embodiments, the first amount of Factor VIIa or Factor VIIa equivalent comprises at least about 100 ug/kg, such as at least about 150 ug/kg or at least about 200 ug/kg; in other embodiments, the second amount of Factor VIIa or Factor VIIa equivalent comprises at least about 75 ug/kg, such as at least about 90 ug/kg; in other embodiments, the third (and optionally fourth) amount of Factor VIIa or Factor VIIa equivalent comprises at least about 75 ug/kg, such as at least about 90 ug/kg.
[0049] In one embodiment, the first dose comprises about 200 ug/kg, the second dose about 100 ug/kg, and the third (and optionally fourth) dose about 100 ug/kg.
[0050] In other embodiments, the patient receives the second amount of Factor VIIa or Factor VIIa equivalent after a period of at least about 45 minutes from the first administration, such as at least about 1 hour, at least about 1.5 hours, at least about 2 hours, at least about 2.5 hours, or at least about 3 hours.
[0051] In other embodiments, the patient receives the third (and optionally fourth) amount of Factor VIIa or Factor VIIa equivalent after a period of at least about 45 minutes from the previous administration, such as at least about 1 hour, at least about 1.5 hours, at least about 2 hours, at least about 2.5 hours, or at least about 3 hours.
[0052] In one embodiment, the patient receives a first dose comprising about 200 ug/kg; after a period of about 1 hour, the patient receives a second dose comprising about 100 ug/kg, and after a period of about 3 hours from the first dose, the patient receives a third dose comprising about 100 ug/kg.
[0053] The following table illustrates different non-limiting embodiments of the invention:
Time post- Time to 2 nd Dose Time to 3 rd Dose Additional injury 1 st Dose 2 nd dose (optional) 3 rd dose (optional) Doses 0-≦1 h >40 mcg/kg 0-1 h >40 mcg/kg 0-1 h >40 mcg/kg As needed 1-2 h 1-2 h ≧3 h ≧3 h 100 mcg/kg 0-1 h 50-100 mcg/kg 0-1 h 50-100 mcg/kg 1-2 h 1-2 h ≧3 h ≧3 h ≧150 mcg/kg 0-1 h 50-100 mcg/kg 0-1 h 50-100 mcg/kg 1-2 h 1-2 h ≧3 h ≧3 h >1-≦3 h >40 mcg/kg 0-1 h >40 mcg/kg 0-1 h >40 mcg/kg As needed 1-2 h 1-2 h ≧3 h ≧3 h 100 mcg/kg 0-1 h 50-100 mcg/kg 0-1 h 50-100 mcg/kg 1-2 h 1-2 h ≧3 h ≧3 h ≧150 mcg/kg 0-1 h 50-100 mcg/kg 0-1 h 50-100 mcg/kg 1-2 h 1-2 h ≧3 h ≧3 h >3-<6 h >50 mcg/kg 0-1 h >50 mcg/kg 0-1 h >50 mcg/kg As needed 1-2 h 1-2 h ≧3 h ≧3 h 100 mcg/kg 0-1 h 50-100 mcg/kg 0-1 h 50-100 mcg/kg 1-2 h 1-2 h ≧3 h ≧3 h ≧150 mcg/kg 0-1 h 50-100 mcg/kg 0-1 h 50-100 mcg/kg 1-2 h 1-2 h ≧3 h ≧3 h >6-<12 h >50 mcg/kg 0-1 h >50 mcg/kg 0-1 h >50 mcg/kg As needed 1-2 h 1-2 h ≧3 h ≧3 h 100 mcg/kg 0-1 h 50-100 mcg/kg 0-1 h 50-100 mcg/kg 1-2 h 1-2 h ≧3 h ≧3 h ≧150 mcg/kg 0-1 h 50-100 mcg/kg 0-1 h 50-100 mcg/kg 1-2 h 1-2 h ≧3 h ≧3 h >12 h >50 mcg/kg 0-1 h >50 mcg/kg 0-1 h >50 mcg/kg As needed 1-2 h 1-2 h ≧3 h ≧3 h 100 mcg/kg 0-1 h 50-100 mcg/kg 0-1 h 50-100 mcg/kg 1-2 h 1-2 h ≧3 h ≧3 h ≧150 mcg/kg 0-1 h 50-100 mcg/kg 0-1 h 50-100 mcg/kg 1-2 h 1-2 h ≧3 h ≧3 h
[0054] It will be understood that the effective amount of Factor VIIa or Factor VIIa equivalent, as well as the overall dosage regimen, may vary according to the patient's haemostatic status, which, in turn, may be reflected in one or more clinical parameters, including, e.g., relative levels of circulating coagulation factors; amount of blood lost; rate of bleeding; haematocrit, and the like. It will be further understood that the effective amount may be determined by those of ordinary skill in the art by routine experimentation, by constructing a matrix of values and testing different points in the matrix.
[0055] For example, in one series of embodiments, the invention encompasses (i) administering a first dose of Factor VIIa or a Factor VIIa equivalent; (ii) assessing the patient's coagulation status after a predetermined time; and (iii) based on the assessment, administering a further dose of Factor VIIa or Factor VIIa equivalent if necessary. Steps (ii) and (iii) may be repeated until satisfactory haemostasis is achieved.
[0056] According to the invention, Factor VIIa or a Factor VIIa equivalent may be administered by any effective route, including, without limitation, intravenous, intramuscular, subcutaneous, mucosal, and pulmonary routes of administration. Preferably, administration is by an intravenous route.
[0000] Combination Treatments:
[0057] The present invention encompasses combined administration of an additional agent in concert with Factor VIIa or a Factor VIIa equivalent. In some embodiments, the additional agent comprises a coagulant, including, without limitation, a coagulation factor such as, e.g., Factor VIII, Factor IX, Factor V, Factor XI, or Factor XIII; or an inhibitor of the fibrinolytic system, such as, e.g., PAI-1, aprotinin, ε-aminocaproic acid or tranexamic acid.
[0058] It will be understood that, in embodiments comprising administration of combinations of Factor VIIa with other agents, the dosage of Factor VIIa or Factor VIIa equivalent may on its own comprise an effective amount and additional agent(s) may further augment the therapeutic benefit to the patient. Alternatively, the combination of Factor VIIa or equivalent and the second agent may together comprise an effective amount for treating trauma. It will also be understood that effective amounts may be defined in the context of particular treatment regimens, including, e.g., timing and number of administrations, modes of administrations, formulations, etc.
[0000] Treatment Outcomes:
[0059] The present invention provides methods and compositions for treating trauma. Treatment encompasses any measurable improvement or amelioration of any parameter that is indicative of the degree of trauma. Non-limiting examples of such parameters include:
Coagulation status, as reflected, e.g. in abnormalities resembling DIC; excessive fibrinolysis; dilutional coagulopathy, including, without limitation, a limited number of platelets and/or an impaired platelet function compared to the platelet count and platelet activity of normal pooled blood Hypothermia, a including having body temperature below about 37° C., such as, e.g., below about 36° C., below about 35° C., or below about 34° C. Indicators of metabolic abnormalities, including, without limitation, acidosis having a blood pH below about 7.5, such as, e.g., below about 7.4, below about 7.3, below about 7.2, or below about 7.1. Blood loss
[0064] Efficacy of the methods of the present invention in treating trauma may also be measured by assessing a statistical decrease in late complications, including, without limitation, Pulmonary embolism (PE), Acute Respiratory Distress Syndrome (ARDS), Disseminated Intravascular Coagulation (DIC), Acute Myocardial Infarction (AMI), Cerebral Thrombosis (CT), Systemic Inflammatory Response Syndrome (SIRS), infections, Multiple Organ Failure (MOF), and Acute Lung Injury (ALI), including death caused by one or more of these syndromes.
[0065] In practicing the present invention, late complications may be assessed using conventional methods, such as, e.g., the Scores described in Tables 1 to 5 herein. Assessments may be performed at least about 20 days from the start of treatment according to the invention, such as, e.g., at least about 30 days, at least about 35 days, or at least about 40 days from the start of treatment.
[0066] Organ damage or organ failure encompass, without limitation, damage to the structure and/or damage to the functioning of the organ in kidney, lung, adrenal, liver, bowel, cardiovascular system, and/or haemostatic system. Examples of organ damage include, but are not limited to, morphological/structural damage and/or damage to the functioning of the organ such as, for example accumulation of proteins (for example surfactant) or fluids due to pulmonary clearance impairment or damage to the pulmonary change mechanisms or alveolo-capillary membrane damage. The terms “organ injury”, “organ damage” and “organ failure” may be used interchangeably. Normally, organ damage results in organ failure. By organ failure is meant a decrease in organ function compared to the mean, normal functioning of a corresponding organ in a normal, healthy person. The organ failure may be a minor decrease in function (e.g., 80-90% of normal) or it may be a major decrease in function (e.g., 10-20% of normal); the decrease may also be a complete failure of organ function. Organ failure includes, without limitation, decreased biological functioning (e.g., urine output), e.g., due to tissue necrosis, loss of glomeruli (kidney), fibrin deposition, haemorrhage, oedema, or inflammation. Organ damage includes, without limitation, tissue necrosis, loss of glomeruli (kidney), fibrin deposition, haemorrhage, oedema, or inflammation.
[0067] Lung damage encompasses, but is not limited to, morphological/structural damage and/or damage to the functioning of the lung such as, for example accumulation of proteins (for example surfactant) or fluids due to pulmonary clearance impairment or damage to the pulmonary change mechanisms or alveolo-capillary membrane damage. The terms “lung injury”, “lung damage” and “lung failure” may be used interchangeably.
[0068] Methods for testing organ function and efficiency, and suitable biochemical or clinical parameters for such testing, are well known to the skilled clinician.
[0069] Such markers, or biochemical parameters of organ function are, for example:
[0070] Respiration: PaO2/FiO2 ratio
[0071] Coagulation: Platelets
[0072] Liver: Bilirubin
[0073] Cardiovascular: Blood pressure and need for vasopressor treatment
[0074] Renal: Creatinine and urine output
[0075] Other clinical assessments comprise ventilator free days, organ failure free days, vasopressor treatment free days, SOFA score and Lung Injury Score evaluation as well as vital signs.
[0076] Methods for testing for coagulophathy or inflammation are also well known to the skilled clinician. Such markers of coagulatory or inflammatory state are, for example, PTT, Fibrinogen depletion, elevation in TAT complexes, ATIII activity, IL-6, IL-8, or TNFR-1.
[0077] Chronic organ damage encompasses, but is not limited to, the long-term damage that may result from ARDS. This residual impairment, in particular of pulmonary mechanics, may include, without restriction, mild restriction, obstruction, impairment of the diffusing capacity for carbon monoxide, or gas-exchange abnormalities with exercise, fibrosing alveolitis with persistent hypoxemia, increased alveolar dead space, and a further decrease in alveolar or pulmonary compliance. Pulmonary hypertension, owing to obliteration of the pulmonary-capillary bed, may be severe and lead to right ventricular failure.
[0078] In the present context, prevention includes, without limitation, the attenuation, elimination, minimization, alleviation or amelioration of one or more symptoms or conditions associated with late complications associated with trauma, including, but not limited to, the prevention of further damage to and/or failure of organs already subject to some degree of organ failure and/or damage, as well as the prevention of damage and/or failure of further organs not yet subject to organ failure and/or damage. Examples of such symptoms or conditions include, but are not limited to, morphological/structural damage and/or damage to the functioning of organs such as, but not limited to, lung, kidney, adrenal, liver, bowel, cardiovascular system, and/or haemostatic system. Examples of such symptoms or conditions include, but are not limited to, morphological/structural damage and/or damage to the functioning of the organs such as, for example, accumulation of proteins (for example surfactant) or fluids due to pulmonary clearance impairment or damage to the pulmonary exchange mechanisms or damage to the alveolo-capillary membrane, decreased urine output (kidney), tissue necrosis, loss of glomeruli (kidney), fibrin deposition, haemorrhage, oedema, or inflammation.
[0079] Attenuation of organ failure or damage encompasses any improvement in organ function as measured by at least one of the well known markers of function of said organs (see Tables 1 to 4) compared to the corresponding value(s) found in trauma patients not being treated in accordance with the present invention.
[0080] Prevention also includes preventing the development of Acute Lung Injury (ALI) into ARDS. ALI is defined by the following criteria (Bernard et al., Am. J. Respir. Crit. Care Med 149: 818-24, 1994): acute onset; bilateral infiltrates on chest radiography; pulmonary-artery wedge pressure of ≦18 mm Hg or the absence of clinical evidence of left atrial hypertension; and PaO 2 :FiO 2 of ≦300. ARDS is defined by the following criteria (Bernard et al., Am. J. Respir. Crit. Care Med 149: 818-24, 1994): acute onset; bilateral infiltrates on chest radiography; pulmonary-artery wedge pressure of ≦18 mm Hg or the absence of clinical evidence of left atrial hypertension, and PaO 2 :FiO 2 of ≦200. (PaO 2 denotes partial pressure of arterial oxygen, and FiO 2 fraction of inspired oxygen).
[0000] Measurement of Late Complications:
[0081] Following are non-limiting examples of methods for assessing the incidence and severity of late complications of trauma.
[0082] 1. The Glasgow Coma Score is determined as follows
Glasgow Coma Scale Eye Opening Motor Response (E) Verbal Response (V) (M) 4 = Spontaneous 5 = Normal conversation 6 = Normal 3 = To voice 4 = Disoriented 5 = Localizes to pain 2 = To pain conversation 4 = Withdraws to 1 = None 3 = Words, but not pain coherent 3 = Decorticate 2 = No words . . . only posture sounds 2 = Decerebrate 1 = None 1 = None Total = E + V + M Normal = 15 Vegetative = 0
[0083] 2. The Multiple Organ Failure (MOF) score is determined as follows:
Multiple Organ Failure Score Multiple Organ Failure An MOF score of 4 or more Grade 1 Grade 2 Grade 3 Grade 0 Dysfunction Dysfunction Dysfunction Pulmonary a Normal ARDS score >5 ADRS score >9 ARDS score >13 Renal Normal Creatinine >1.8 mg/dL Creatinine >2.5 mg/dL Creatinine >5 mg/dL Hepatic b Normal Bilirubin >2 mg/dL Bilirubin >4 mg/dL Bilirubin >8 mg/dL Cardiac c Normal Minimal inotropes Moderate inotropes High inotropes a ARDS score = A + B + C + D + E, PCWP ≦18 cm H 2 0, or clinical setting where high PCWP is not anticipated. b Biliary obstruction and resolving haematoma excluded. c Cardiac index <3.0 L/min/m2 requiring inotropic support. Minimal dose, dopamine or dobutamine <5 μg/kg/min; moderate dose, dopamine or dobutamine 5-15 μg/kg/min; high dose, greater than moderate doses of above agents. Healthy = 0 Severe = 15
[0084] 3. The ARDS Score is determined as follows:
ARDS Score A. Pulmonary findings by plain chest radiography 0 = Normal 1 = Diffuse, mild interstitial marking/opacities 3 = Diffuse, moderate airspace consolidation 4 = Diffuse, severe airspace consolidation B. Hypoxemia - Pao 2 /Fio 2 (mmHg) 0 = Normal 1 = 175-250 2 = 125-174 3 = 80-124 4 = <80 C. Minute ventilation (L/min) 0 = <11 1 = <11-13 2 = <14-16 3 = <17-20 4 = >20 D. Positive and expiratory pressure (cm H 2 0) 0 = <6 1 = 6-9 2 = 30-39 3 = 14-17 4 = >17 E. Static compliance (mL/cmH 2 0) 0 = >50 1 = 40-50 2 = 30-39 3 = 20-29 4 = <20 Normal = 0 Severe = 20
[0085] 4. The SIRS Score is determined as follows:
Systemic Inflammatory Response Syndrome Score A SIRS score (1 to 4) calculated for each subject. One point for each component present: fever or hypothermia tachypnea tachycardia leukocytosis SIRS is present when two or more of the following criteria are met: temperature greater than 38° C. or less than 36° C. heart rate greater than 90 beats per minute respiratory rate greater than 20 breaths per minute or PaCO 2 less than 32 white blood cell count greater than 12,000/mm 3 or less than 4,000/,mm 3 or presence of 10% bands Normal = 0 Severe = 4
[0086] 5. DIC is measured as follows:
DIC Term: Definition: Disseminated Clinical history of: an intense clotting stimulus and Intravascular shock (infection, trauma, tissue damage, surgery) Coagulation followed by bleeding. Blood tests: fibrinogen ≦150 mg/dL platelet count <150,000//mm 3 or drop of 100,000/mm 3 from last valve D-dimer >500 μg/L
[0087] In one series of embodiments, the practice of the present invention results in one or more of the following clinical outcomes:
A decrease in blood loss, including a complete cessation of blood loss An improvement in one or more parameters of shock, including, e.g., hypothermia and blood pH.
[0090] In one series of embodiments, the practice of the present invention results in one or more of the following clinical outcomes:
A Glasgow Coma Score of greater than about 9 when measured 20 days after start of treatment; A Glasgow Coma Score of greater than about 11 when measured 30 days after start of treatment; A Glasgow Coma Score of greater than about 13 when measured 40 days after start of treatment; An MOF Score of less than about 4 when measured 20 days after start of treatment; An MOF Score of less than about 3 when measured 30 days after start of treatment; An MOF Score of less than about 2 when measured 40 days after start of treatment; An ARDS Score of less than about 8 when measured 20 days after start of treatment; An ARDS Score of less than about 6 when measured 30 days after start of treatment; An ARDS Score of less than about 4 when measured 40 days after start of treatment; An SIRS Score of less than about 3 when measured 20 days after start of treatment; An SIRS Score of less than about 2 when measured 30 days after start of treatment; An SIRS Score of less than about 1 when measured 40 days after start of treatment:
[0103] a Any combination of any of the above Glasgow Coma Scores, MOF Scores, ARDS Scores, and/or SIR Scores.
[0000] Other Indices of Treatment:
[0104] The efficacy of the methods of the present invention may also be assessed using other clinical parameters, including, without limitation, reduction in any one or more of the following parameters relative to a similar patient who has not been administered Factor VIIa or a Factor VIIa equivalent according to the invention: a reduction in units of blood, plasma, red blood cells, packed red blood cells, or volume replacement products that need to be administered; a decrease in the number of days of hospitalization after suffering a trauma, including a decrease in the number of days that a patient may spend in an intensive care unit (ICU) and a decrease in the number of days in which certain interventions (such as, e.g., a ventilator) are required. Non-limiting examples of outcomes include: (i) a reduction in the units of blood, plasma, red blood cells, packed red blood cells, or volume replacement products that need to be administered by at least about 2 units, 4 units, or 6 units; (ii) a decrease in ICU days by 1 day, 2 days, or 4 days; (iii) a reduction on the number of days on a ventilator by 1 day, 2 days, or 4 days; (iv) a reduction in the total days of hospitalization by 2 days, 4 days, or 8 days.
[0105] The following examples are intended as non-limiting illustrations of the present invention.
EXAMPLE 1
Factor VIIa Administration to Trauma Victims
[0106] The following study was performed in order to assess efficacy and safety of recombinant activated coagulation factor VII (rFVIIa, NovoSeven®) as adjunctive therapy for bleeding control in severe trauma
[0107] Methods A multicenter, randomized, double-blind trial compared rFVIIa with placebo. Study product was administered as 3 i.v. injections (200, 100 and 100 μg/kg) at time 0, 1 and 3 h after transfusion of 8 units of red blood cells (RBC). Patients were monitored for 48 hours after dosing with 30-day follow-up. Standard local hospital treatment was given throughout. Blunt and penetrating groups were separately analysed.
[0000] Results
[0108] In total, 143 blunt and 134 penetrating patients were analyzed. In patients with blunt trauma (Injury Severity Score mean±SD: 33±13), there was a trend to decreased RBC transfusion within 48h of dosing (primary endpoint) in the rFVIIa group vs placebo when adjusting for patients who died within 48 h (p=0.07). Excluding deceased patients, the reduction in RBC was significant (p=0.02). In particular, fewer patients in the rFVIIa group received massive transfusion (>20 RBC units). Fewer patients with predefined critical complications were observed with rFVIIa in blunt trauma (Table). For patients with penetrating trauma, transfusion results were similar but not statistically significant. The number of thromboembolic events was similar between treatment groups.
[0000] Conclusions
[0109] rFVIIa showed a good safety profile in this high-risk trauma population. RBC requirements were significantly reduced with rFVIIa in blunt trauma. Trends to reduced complications warrant further investigation.
TABLE Patients with critical events within 30 days (blunt group) Placebo rFVIIa (N = 74) (N = 69) Multiple Organ Failure 7 (9%) 3 (4%) Acute Respiratory Distress 12 (16%) 3 (4%) Syndrome Death 22 (30%) 17 (25%) ICU-free time Mean 10.5 d Mean 12.6 d Ventilator-free time Mean 13.7 d Mean 15.4 d
Results from blunt trauma indicate that patients treated with NovoSeven® have fewer complications and spend less time in intensive care units than patients receiving conventional treatment and also that overall mortality was lower in the group treated with NovoSeven®.
EXAMPLE 2
Efficacy of Factor VIIa Given in Conjunction with Standard Therapy in the Treatment of Trauma
[0000] Trial Design:
[0110] A multi-centre, randomised, double-blind, parallel group, placebo-controlled trial was conducted in subjects with severe blunt and/or penetrating trauma injuries. Subjects were recruited for screening upon admittance to the trauma centre. In conjunction with the trial product, they received standard treatments for injuries and bleeding and any other procedures deemed necessary by the physician in charge of coordinating the trauma team. The trial is comprised of two treatments arms. Eligible subjects, upon receiving 6 units of PRBC within a 4-hour period, will be equally allocated to one of the following arms:
Standard therapy in conjunction with three single doses (volume equal to 200 μg/kg+100 μg/kg+100 μg/kg) of placebo administered over a 3 hour period Standard therapy in conjunction with three single doses (200 μg/kg+100 μg/kg+100 μg/kg) of rFVIIa administered over a 3 hour period
[0113] The first dose of rFVIIa or placebo (trial product) were administered once the subject had received 8 units of PRBC and followed 1 hour later by the second dose and an additional 2 hours later by the third and final dose of trial product. The trial drug were given to subjects who in the opinion of the attending surgeon required more transfusion than 8 units of PRBC. A 48-hour observation period, starting upon administration of the first dose, as well as a 30-day follow-up assessment, were conducted. The trial product was administered intravenously as a slow bolus injection. Specific procedures such as physical examination, laboratory assessment and adverse event evaluation were conducted throughout the trial. The subjects were monitored throughout the study for several endpoints including number of PRBC units required, adverse events, survival, and changes in coagulation related parameters.
[0114] In order to evaluate the mortality due to haemorrhage, a sequential analysis of every set of 20 subjects treated was performed starting when mortality data from first 100 subjects were available. Safety was monitored and evaluated continuously taking into account all SAEs as they were reported during the trial.
[0000] Trial Products:
[0115] Activated recombinant human FVII (rFVIIa) and placebo will be supplied as freeze-dried powder in single use vial of 2.4 mg to be reconstituted with sterile water for Ph.Eur. injection.
[0000] Trial Population:
[0116] Approximately 280 subjects (140 per treatment arm), 16 years or older, with severe blunt and/or penetrating trauma injuries were enrolled.
[0000] Inclusion Criteria
[0117] Subjects entering the trial met the following inclusion criteria:
1. Injury(ies) due to a blunt and or penetrating trauma. 2. Receipt of 6 units of PRBC within a 4 hour period following admittance to the trauma centre 3. Receipt of 8 units of PRBC upon administration of trial drug. 4. Known age of ≧16 or legally of age according to local law and ≦65.
Exclusion Criteria:
[0122] Subjects meeting the following criteria were excluded from the study:
1. Prehospital cardiac arrest. 2. Cardiac arrest in the ER or OR. 3. Gunshot wound to the head. 4. Glasgow Coma Scale<8. 5 . Base deficit of >15 mEq/l or severe acidosis (pH<7.0.). 6. Transfusion of 8 units or more of PRBC prior to arrival in trauma centre. 7. Known congenital bleeding disorder. 8. Currently participating or has participated in another investigational drug trial within the last 30 days. 9. Known pregnancy or positive pregnancy test at enrolment. 10. Previous participation in this trial. 11. Known treatment with vitamin K antagonist, low-dose heparin before trial drug is given. 12. Injury sustained ≧12 hours prior to randomisation. 13. Estimated weight >130kg.
Assessments:
[0136] Treatment efficacy is based on the evaluation of the following variables for the period from SOT to 48 hours:
Timing and number of deaths due to bleeding and all other causes. Timing and number of transfusion units of the following blood products administered:
PRBC (timing) FFP Platelets Cryoprecipitate
Number of times subject is taken to surgery due to bleeding. Time interval between first dose of study drug and reaching normal range of coagulation PT, normal temperature, and acid base status. Pharmacokinetic evaluations and population pharmacokinetic evaluation Overall survival at Day 30 Timing and number of complications including MOF, ARDS, and infections occurring from SOT to Day 30. Number of days of hospitalisation including days in the Intensive Care Unit (ICU), bed confinement and/or on a ventilator in the period from SOT to Day 30.
Prior to Onset of Treatment (Treatment Period 0)
Blood Sampling was Performed for:
[0149] FVII:C (cf. below)
[0150] Coagulation related parameters and haematology (cf. below)
[0151] PT (cf. below)
[0152] Blood chemistry (cf.below)
[0000] After First Trial Product Administration and the Following 24 Hours.
[0000] The Following was Recorded and/or Investigated:
[0153] Mortality and time of death
[0154] Vital signs at 30 min, 1, 2, 4, 6, 8, 12, 18 and 24 hours (cf. below). Glasgow Coma
[0155] Score only at 24 hours.
[0156] Number of transfusion product units required. (cf. below).
[0157] I.V. fluid including the composition, e.g., colloid, crystalloids (cf. below).
[0158] Number of times subject is taken to surgery and reason for surgery (cf.below).
[0159] Adverse events).
[0160] ARDS, infection, MOF.
[0000] Blood Sampling was Performed for:
[0161] Coagulation related parameters at 1, 4, 8, 12, and 24 hours (cf below).
[0162] Haematology at 1, 4, 8, 12 and 24 hours (cf. below).
[0163] FVII:C 2 to 4 samples, one in each of the following time intervals: 0-1 hour, 1-3 hours, 3-8 hours, and 8-12 hours (cf. below).
[0164] Frequent sampling: FVII:C at 30 mins, 1, 2, 3, 4, 6, 8, and 12 hours (cf. below).
[0165] PT at 1, 4, 8, 12, and 24 hours.(cf. below) Frequent sampling: 30 min and 1, 2, 3, 4, 6, 8, 12, 18, and 24 hours. (cf. below) Blood chemistry at 24 hours (cf. below).
[0000] From 24 to 48 Hours
[0166] Mortality and time of death.
[0167] Vital signs every 6 hours.
[0168] Number of transfusion product units required.
[0169] I.V. fluid volume including composition, e.g., colloid, crystalloid Physical examination changes from baseline.
[0170] Number of times subject is taken into surgery and reason for surgery.
[0171] ECG at 48 hours ARDS, infections, MOF Adverse events
[0000] Blood Sampling will be Performed at 36 and 48 Hours for the Following:
[0172] Coagulation related parameters
[0173] Haematology
[0174] PT
[0175] Blood chemistry—only at 48 hours
[0000] Follow-Up Visit—Day 30
[0176] Mortality and date and time of death
[0177] Days of hospitalisation including number of days in Intensive Care Unit and of bed confinement.
[0178] Days on Ventilator
[0179] Serious Adverse Events
[0180] ARDS, infection, MOF
[0000] Analyses
[0000] Coagulation-Related Parameters and Haematology
[0181] Blood was drawn at the following time points: immediately prior to first treatment and at 1, 4, 8, 12, 24, 36, 48 hours after first treatment for the analysis of:
[0182] Coagulation-Related Parameters
[0183] APTT, Fibrinogen, D-dimers, Anti thrombin-III, F1+2, TAT
[0184] Haematology
[0185] Platelets, Haematocrit, Haemoglobin and White Blood Cells
[0186] Blood Chemistry
[0187] Blood was drawn at the following time points: prior to the first treatment and at 24, 48 hours after the first treatment for the analysis of:
[0188] S-Bilirubin, S-albumin, S-creatinine, S-potassium, S-sodium, S-alanine aminotransferase.
[0189] FVII:C (Pharmacokinetics)
[0190] Fifty subjects was frequently sampled for FVII:C, and blood was be drawn at the following time points: immediately prior to first treatment and at 30 minutes, 1, 2, 3, 4, 6, 8, and 12 hours for the analysis of FVII:C.
[0191] All other subjects had blood drawn 2-4 times, one sample in 2 to 4 of the following time intervals: 0-1 hour (immediately after first dose and before next dose is given), 1-3 hours (immediately after second dose and before next dose is given), 3-8 hours (immediately after third dose), and 8-12 hours. The samples can be taken any time in the time interval. Exact time of sampling was recorded.
[0000] Prothrombin Time
[0192] For the 50 subjects having frequent FVII:C sampling, blood was be drawn at the following time points: immediately prior to first treatment and at 30 minutes, 1, 2, 3, 4, 6, 8, 12, 18, 24, 36 and 48 hours for the analysis of Prothrombin time (PT).
[0193] All other subjects had blood drawn at the following time points: immediately prior to first treatment and at 1, 4, 8, 12, 24, 36, and 48 hours.
[0000] Vital Signs
[0194] Vital signs was recorded prior to treatment and at 30 min, 1, 2, 4, 6, 8, 12, 16, 18 and then every 6 hours until 48 hours from first dose upon administration of the first dose of the study drug (otherwise as the condition of the subject demanded).
[0000] The following was recorded:
[0195] Body temperature (C [rectal, oral or ear])
[0196] Blood pressure (mm Hg) (systolic/diastolic) will in addition be recorded at scene of accident during pre-hospital phase.
[0197] Pulse (beats/min) will in addition be recorded at scene of accident during pre-hospital phase.
[0198] pH
[0199] Respiration rate (only when off ventilator) will in addition be recorded at scene of accident during pre-hospital phase.
[0200] Respiratory PaO2/FiO2, PaCO2
[0201] Positive end expiratory pressure (cm H20)
[0202] Glasgow coma score (cf. the present specification) was recorded at scene of accident during pre-hospital phase at trauma centre: before treatment, 24 and 48 hours from first dose of study drug. If the patient was on ventilator, the GCS was not be recorded.
EXAMPLE 3
In Vitro Evaluation of the Impact of Colloid Haemodilution, Acidosis, and Hypothermia on the Effect of Recombinant Factor VIIa
[0203] The following experiments were performed to assess the effect on clot formation of Factor VIIa under physiological conditions that are clinically relevant in trauma, ie., low pH (acidosis), low temperature (hypothermia), and colloid haemodilution.
[0000] 1. Methods
[0204] Blood Collection: WB was obtained using a 21-gauge needle from six healthy volunteers. Samples were drawn into tubes containing citrate, mixing one part of citrate with nine parts of blood. The first tube of collected blood from each participant was discarded. After the blood samples had rested for 30 minutes at room temperature, they were manipulated to mimic one specific clinical situation, as outlined below.
[0205] To stimulate acidosis, WB (2 mL) was made acidic (pH 7) by the addition of 140 μL of N-2-hydroxyethylpiperazine-N′-2-ethanesulfonic acid (HEPES) 1 M buffer, adjusted to pH 7. To simulate hypothermia, the temperature of the blood samples was lowered to 32° C. To simulate haemodilution, all solutions were mixed with citrate (10% v/v) to ensure adequate anticoagulation of the haemodiluted WB. WB was then diluted by 20%, 40%, and 60% (V/V) with one of three different colloid solutions: Human serum albumin 5%, MW=68 000; Hetastarch 6% (Hespan®, duPont Merck, Wilmington, Del., USA), MW=450 000; or Hydroxyethyl starch (HES) 130/0.4 (Voluven®, Fresenius Kabi, Bad Homburg, Germany), MW=130 000.
[0206] Thromboelastography Whole Blood Coagulation Analysis: Coagulation was initiated by adding tissue factor 1:50 000 (Innovin®, Dade Behring, Deerfield, Ill., USA) to WB and recalcifying with 15 mM calcium chloride (free CaCl 2 ˜2-3 mM). The final concentration of tissue factor in WB corresponded to 0.12 pM. Experiments were performed in the absence or presence of 25 nM rFVIIa (25 nM 90 μg/kg). The haemostatic process was recorded by use of a TEG coagulation analyzer (5000 series TEG analyzer, Haemoscope Corporation).
[0207] The clot formation rate (CFR) was recorded as the TEG α-angle (Figure); a greater CFR value is indicative of a more robust clot formation.
[0208] Statistical Analysis: Pharmacodynamic parameters were summarized as means and standard deviations (SD). The student's t-test was performed on averaged data, with two-sided a set at 0.05.
[0000] 2. Results
[0209] Acidosis: Lowering the pH to 7.0 significantly decreased the CFR. Addition of rFVIIa resulted in a significant increase in the CFR.
[0210] Hypothermia: Lowering the WB temperature to 32° C. resulted in a trend toward a modest decrease of the CFR. Addition of 25 nM rFVIIa significantly increased the CFR.
[0000] Haemodilution:
[0000]
Albumin: Haemodilution with albumin was not associated with impairment of clot formation (Table). For the 20% and 40% dilutions, but not the 60% dilution, addition of rFVIIa significantly increased the CFR.
Hetastarch: Haemodilution with hetastarch was associated with impaired clot formation at 40% and 60% only (Table). For the 20%, but not the 40% and 60% dilutions, addition of rFVIIa significantly increased the CFR. At 60% dilution, the CFR following addition of rFVIIa remained significantly reduced compared to the CFR in normal WB.
HES: All dilutions of WB with HES were associated with reduced CFRs relative to normal WB (Table). The addition of rFVIIa improved the CFR only at the 20% dilution level. At 40% and 60% dilution, the CFR following addition of rFVIIa remained significantly reduced compared with the CFR in normal WB. Of note, increasing the rFVIIa concentration to 200 nM (corresponding to the plasma concentration following administration of 720 μg/kg) significantly improved the CFR at 40% dilution (48±3) but failed to improve the CFR at 60% dilution, which remained significantly reduced compared with the CFR in normal WB.
3. Conclusions
[0214] The in vitro clot-promoting effects of rFVIIa were not adversely affected by acidosis, hypothermia, or haemodilution below 40%. However, more severe degrees of colloid haemodilution with 6% hetastarch and HES130/0.4 impaired the effect of rFVIIa on clot formation, as measured in vitro by TEG.
CFR rFVIIa No addition (25 nM) Normal WB 52 ± 8 Acidosis (pH 7.0) 44 ± 7 58 ± 6 Hypothermia (32° C.) 51 ± 9 59 ± 9 Haemodilution albumin 20% 54 ± 8 65 ± 4 Haemodilution albumin 40% 55 ± 8 63 ± 4 Haemodilution albumin 60% 49 ± 7 49 ± 7 Haemodilution hetastarch 20% 51 ±± 5 58 ± 6 Haemodilution hetastarch 40% 46 ± 4 49 ± 8 Haemodilution hetastarch 60% 35 ± 5 36 ± 19 Haemodilution HES 130/0.4 20% 35 ± 4 49 ± 6 Haemodilution HES 130/0.4 40% 39 ± 6 38 ± 7 Haemodilution HES 130/0.4 60% 32 ± 6 31 ± 4
EXAMPLE 4
Efficacy of Factor VIIa Given in Conjunction with Standard Therapy in the Treatment of Trauma
[0215] The following study was performed in order to assess efficacy and safety of recombinant activated coagulation factor VII (rFVIIa, NovoSeven®) as adjunctive therapy for bleeding control in severe trauma
[0000] 1. Methods
[0216] Severely bleeding patients with severe blunt and/or penetrating trauma injury were randomized to rFVIIa (200+100+100 μg/kg) or placebo in addition to standard treatment. The first dose followed the 8th RBC (red blood cell) unit, with additional doses 1 and 3 hours later.
[0217] Patients were monitored closely during the 48-hour period following the first dose of trial product. This included recording transfusion and infusion requirements, adverse events and surgical procedures. Blood was drawn at frequent intervals to evaluate changes in coagulation and blood biochemistry parameters. Mortality, time on ventilator, hospitalization data, and serious adverse events including pre-defined critical complications (MOF and acute respiratory distress syndrome (ARDS)) as reported by the trial sites were recorded until day 30.
[0218] Endpoints
[0219] To assess the haemostatic effect, the primary endpoint was the number of RBC units (allogeneic RBC, autologous RBC and whole blood) transfused during the 48-hour period following first dose of trial product. Outcome of therapy was further assessed through requirement for other transfusion products, mortality, days on the ventilator, and hospitalization data. Safety outcomes comprised frequency and timing of adverse events, and changes in coagulation-related laboratory variables (activated partial thromboplastin time (aPTT), platelets, fibrinogen, D-dimer, antithrombin III, prothrombin fragments 1+2, and thrombin-antithrombin complex). Because mortality is not a sensitive variable in a trauma population, we studied a composite endpoint that comprised death, MOF, and ARDS. Safety reporting on MOF and ARDS was based on pre-specified definitions provided in the study protocol.
[0220] Statistical Analysis
[0221] We calculated sample size according to the transfusion data of a retrospective study in a severe blunt trauma patient population.14 In patients with an initial GCS≧8, a 0-48 h RBC transfusion requirement of 12.4 (SD: 6.2) units was found. We estimated that 70 patients in each treatment group would be required to detect a 60% reduction in 0-48 h RBC requirement from 4.4 units to 1.8 units in addition to the 8 pre-dose units, with 80% power and a 5% Type 1 error. As the trial involved two trauma populations and two treatment groups, a total sample size of 280 patients was planned for. Blunt and penetrating trauma populations were analyzed separately. Results pertain to all consented and randomized patients who received trial drug. The type 1 error was set to 5%. All analyses were defined a priori, unless otherwise stated.
[0222] The total number of RBC units transfused within 48 hours from start of trial product treatment (the primary endpoint) was compared between treatment groups by use of one-sided Wilcoxon-Mann-Whitney rank test. A one-sided test was selected as it was not expected that administration of rFVIIa would increase transfusion requirements. Separate analyses were performed where patients who died within 48 hours were either excluded or assigned to the worst outcome. Priority was given to the analysis where patients who died within 48 hours were excluded because 1) in a large proportion of these patients, care was futile 2) 48-hour transfusion requirements could not be objectively assessed for patients who were alive for only a few hours. The Hodges-Lehman estimate was used to estimate the difference in RBC transfusions. Total RBC were calculated as the sum of autologous RBC, allogeneic RBC and whole blood, with each component normalized to standard units of RBC (equal to a volume of 295 mL with a haematocrit of 63%, as this was the average across all sites).
[0223] The Fisher's exact test was used for comparing the number of patients requiring massive transfusion (defined post hoc as >20 units of RBC inclusive of the 8 pre-dose units) and number of patients experiencing MOF, ARDS, and/or death within 30 days. The relative risk reduction of massive reduction and its 95% confidence interval (CI) were calculated. Effects on 48-hour mortality were analyzed using chi-square testing.
[0000] 2. Results
[0224] Among 301 patients randomized, 143 blunt trauma patients and 134 penetrating trauma patients were eligible for analysis. Treatment groups were well matched in terms of baseline characteristics within each of the trauma populations (Table 1). Patients were predominantly young males and were characterized by being coagulopathic, acidotic and hypothermic. Causes of penetrating trauma were primarily gunshots (68%) and stab wounds (30%), whereas 75% of blunt trauma was due to traffic-related injury.
[0225] Bleeding Control
[0226] The primary endpoint, RBC requirements during the 48-hour observation period following the initial dose of trial product, is shown for patients alive at 48 hours in FIG. 1 . In patients with blunt trauma, rFVIIa significantly reduced 48-hour RBC requirements by 2.6 units compared with placebo (p=0.02). The need for massive transfusion was reduced from 20/61 (33%) patients in the placebo group to 8/56 (14%) in the rFVIIa group, which represents a relative risk reduction of 56% (95% CI: [9%; 79%]; p=0.03) ( FIG. 2 ). In patients with penetrating trauma, no significant effect of rFVIIa was observed with respect to 48-hour RBC requirements with an RBC reduction of 1.0 unit (p=0.10). The need for massive transfusion in penetrating trauma was reduced from 10/54 (19%) patients in the placebo group to 4/58 (7%) in the rFVIIa group, which represents a relative risk reduction of 63% (95% CI: [-12%; 88%]; p=0.08) ( FIG. 2 ). When assigning worst outcome to deceased patients, statistical significance was not reached in either trauma population (Table 2).
[0227] No significant differences between treatment groups were observed in either trauma population with respect to administration of fresh frozen plasma, platelets, cryoprecipitate, crystalloids or colloids (data not shown).
[0228] Clinical Outcome and Safety
[0229] Results for adverse events, mortality, ventilator-free days and ICU-free days are summarized in Table 3. Positive trends in favour of rFVIIa were observed for these endpoints, especially those concerning critical complications (ARDS, MOF and/or death). Survival curves are depicted in FIG. 3 .
[0230] Adverse events occurred at similar frequency and severity between treatment groups. Overall, the adverse event profile was similar between rFVIIa-treated and placebo-treated patients, and there were no apparent treatment-dependent patterns in the types of adverse events reported. As can be expected in this severely injured patient population, the three most frequently reported serious adverse events were ARDS, MOF, and sepsis.
[0231] A total of 12 thromboembolic adverse events were reported by the investigators during the trial period; 6 in rFVIIa-dosed patients and 6 in placebo-dosed patients. In patients with blunt trauma, two incidences of pulmonary embolism and a subclavian vein thrombosis (after central line) were recorded in the placebo group, whereas one jugular vein thrombosis (after central line) and one arterial limb thrombosis were recorded in rFVIIa-treated patients. In patients with penetrating trauma, one cerebral infarction and one DVT was noted in each treatment group. In addition, a mesenteric vein thrombosis was recorded in the placebo group and an intestinal infarction (at the site of operation) and an event of phlebothrombosis was noted in the rFVIIa group. All 12 thromboembolic events were reported as serious adverse events.
[0000] 3. Conclusions
[0232] rFVIIa assisted in the control of bleeding in severe blunt trauma and resulted in a significant reduction in RBC transfusion. Similar trends were observed in penetrating trauma. The safety of rFVIIa was established in this trauma population within the investigated dose range
TABLE 1 Baseline Characteristics Blunt trauma Penetrating trauma Placebo rFVIIa Placebo rFVIIa Variable (N = 74) (N = 69) (N = 64) (N = 70) Male sex 52 (70%) 48 (70%) 60 (94%) 66 (94%) Age (years) 35 ± 13 33 ± 13 32 ± 10 29 ± 10 ISS 32 ± 13 34 ± 12 26 ± 11 26 ± 15 Number of ISS body regions injured* 1 4 (5%) 6 (9%) 25 (39%) 21 (30%) 2-3 36 (49%) 29 (42%) 36 (56%) 43 (61%) >3 32 (43%) 33 (48%) 3 (5%) 6 (9%) Glasgow Coma Score ≦8 8 (11%) 8 (12%) 5 (8%) 3 (4%) 9-12 18 (24%) 11 (16%) 8 (13%) 6 (9%) 13-15 48 (65%) 47 (68%) 51 (80%) 60 (86%) Time from injury to hospitalization 0-1 hours 27 (36%) 21 (30%) 40 (63%) 41 (59%) 1-2 hours 23 (31%) 23 (33%) 10 (16%) 8 (11%) 2-4 hours 10 (14%) 11 (16%) 3 (5%) 3 (4%) >4 hours 7 (9%) 3 (4%) 1 (2%) 5 (7%) Unknown 7 (9%) 11 (16%) 10 (16%) 13 (19%) Time from hospitalization to trial product dosing 0-2 hours 15 (20%) 19 (28%) 8 (13%) 11 (16%) 2-4 hours 24 (32%) 18 (26%) 23 (36%) 25 (36%) 4-6 hours 17 (23%) 12 (17%) 16 (25%) 15 (21%) >6 hours 17 (23%) 18 (26%) 17 (27%) 19 (27%) Unknown 1 (1%) 2 (3%) 0 (0%) 0 (0%) Vital signs Systolic arterial blood 111 ± 27 102 ± 24 114 ± 25 111 ± 24 pressure (mmHg) Body temperature 35.3 ± 1.6 35.2 ± 1.6 35.2 ± 1.2 35.3 ± 1.3 (° C.) Biological variables Hemoglobin (g/dL) 9.1 ± 2.8 9.3 ± 2.5 8.8 ± 3.0 8.5 ± 2.8 pH 7.26 ± 0.11 7.24 ± 0.13 7.28 ± 0.11 7.27 ± 0.09 aPTT (seconds) 51 ± 28 49 ± 24 54 ± 26 49 ± 27 PT (seconds) 19 ± 6 20 ± 8 22 ± 6 18 ± 5 Data intervals refer to means ± SD. Other data refer to number (and percentage) of patients. *Body regions as defined for the Injury Severity Scale. No significant differences between rFVIIa and placebo groups were observed. aPTT: activated partial thromboplastin time; PT: prothrombin time
[0233]
TABLE 2
Total RBC transfusions (units) during 48 hours after first dose
of trial drug
Placebo
rFVIIa
Estimated
Median
Median
RBC
n
(range)
n
(range)
reduction*
p
Blunt
N = 74
N = 69
All patients
72
7.2 (0-35)
64
7.8 (0-48)
2.00 ♯
0.07 ♯
Alive at 48 h
59
7.5 (0-35)
52
7.0 (0-29)
2.60
0.02
Penetrating
N = 64
N = 70
All patients
61
4.8 (0-41)
69
4.0 (0-37)
0.20 ♯
0.24 ♯
Alive at 48 h
52
4.2 (0-41)
57
3.9 (0-30)
1.00
0.10
*Hodges-Lehman point estimate of the shift in transfusion amount from placebo to active group.
♯ Patients who died within 48 hours were assigned the highest rank.
[0234]
TABLE 3
Adverse events and clinical outcomes
Blunt trauma
Penetrating trauma
Placebo
rFVIIa
Placebo
rFVIIa
(N = 74)
(N = 69)
(N = 64)
(N = 70)
Serious adverse events
Patients with events
49 (66%)
44 (64%)
36 (56%)
36 (51%)
Number of events
109
91
76
59
Thromboembolic adverse events
Patients with events
3 (4%)
2 (3%)
3 (5%)
4 (60%)
Number of events
3
2
3
4
48-hour mortality
13 (18%)
13 (19%)
p = 0.84
10 (16%)
12 (17%)
p = 0.85
Patients wth critical
complications within 30
days ♯
ARDS
12 (16%)
3 (4%)
p = 0.03
5 (8%)
4 (6%)
p = 0.74
MOF
9 (12%)
5 (7%)
p = 0.41
7 (11%)
2 (3%)
p = 0.09
Death
22 (30%)
17 (25%)
p = 0.58
18 (29%)
17 (25%)
p = 0.69
Patients with ARDS,
31 (42%)
20 (29%)
p = 0.16
22 (34%)
20 (29%)
p = 0.57
MOF, and/or death
Ventilator-free days
14 (0-30)
17 (0-30)
p = 0.53
21 (0-30)
26 (0-30)
p = 0.18
(median and range)
ICU-free days
8 (0-29)
13 (0-30)
p = 0.22
19 (0-30)
23 (0-30)
p = 0.28
(median and range)
MOF: Multiple organ failure;
ARDS: Acute respiratory distress syndrome;
ICU: Intensive care unit
[0235] All patents, patent applications, and literature references referred to herein are hereby incorporated by reference in their entirety.
[0236] Many variations of the present invention will suggest themselves to those skilled in the art in light of the above detailed description. Such obvious variations are within the full intended scope of the appended claims.
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The invention relates to the use of Factor VIIa or a Factor VIIa equivalent for the manufacture of a medicament for treatment of trauma.
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TECHNICAL FIELD
[0001] The present invention relates generally to a metal halide lamp. More specifically, this invention relates to a metal halide lamp for use in irradiating light of ultraviolet rays to cause a photochemical reaction which is suitable for use with, for example, a drying process of inks and paints and a curing process of resins and the like.
BACKGROUND ART
[0002] In recent years, metal halide lamps for irradiating light of ultraviolet rays are utilized in a wide variety of fields such as a printing process, a painting process and a resin sealing process. As metal halide lamps for use in these processes, there have hitherto been developed lamps capable of producing light of higher illumination level in order to efficiently carry out the treatments such as printing, painting and sealing in a short period of time. A high-pressure mercury lamp is a main current of a light source but there has been known a metal halide lamp of which luminous efficiency in the ultraviolet region is higher than that of the high-pressure mercury lamp. A metal halide lamp includes an arc tube into which metals are sealed as halides to produce light of a spectrum peculiar to metals.
[0003] The inventors of the present application are aware of the following patent literatures concerning such metal halide lamps for use in irradiating light of ultraviolet rays. Relevant parts in the respective patent literatures will be cited and mentioned.
CITATION LIST
Patent Literature
[0000]
Patent Literature 1: Japanese unexamined patent publication No. 50-044675 (Date of laid-open: Apr. 22, 1975) “Metal vapor discharge lamp” (Applicant: IWASAKI ELECTRIC CO., LTD.)
Patent Literature 2: Japanese unexamined patent publication No. 52-16886 (Date of laid-open: Feb. 8, 1977) “Metal vapor discharge lamp” (Japanese examined patent publication No. 58-018743, Japanese Patent No. 1,262,477) (Applicant: IWASAKI ELECTRIC CO., LTD.)
Patent Literature 3: Japanese unexamined patent publication No. 02-072551 (Date of laid-open: Mar. 12, 1990) “Metal vapor discharge lamp” (Applicant: TOSHIBA LIGHTING AND TECHNOLOGY CORPORATION)
Patent Literature 4: Japanese unexamined patent publication No. 10-069883 (Date of laid-open: Mar. 10, 1998) “Metal vapor discharge lamp” (Applicant: IWASAKI ELECTRIC CO., LTD.)
Patent Literature 5: Japanese unexamined patent publication No. 2002-008588 (Date of laid-open: Jan. 11, 2002) “Metal vapor discharge lamp” (Japanese patent No. 4,411,749) (Applicant: JAPAN STORAGE BATTERY CO., LTD.)
The patent literature 1 discloses a metal vapor discharge lamp including an arc tube into which a halogen of a quantity of 0.1×10 −6 to 1.0×10 −6 gram atom in a per cubic centimeter of internal volume of the arc tube and an iron of a quantity of ½ to 3 times the quantity of the halogen in atomic ratio are sealed (claim for patent).
[0010] The patent literature 2 discloses a metal vapor discharge lamp including an arc tube into which a halogen, an iron and a tin are sealed together with mercury of a quantity large enough to maintain an arc discharge and a rare gas of a proper quantity. A quantity of halogen sealed into the arc tube is selected to be 1.0×10 −5 to 1.0×10 −8 gram atom in a per cubic centimeter of internal volume of the arc tube, a total quantity of an iron and a tin relative to the quantity of the halogen is selected to be ½ to 3 in atomic ratio, a quantity of tin relative to the iron is selected to be 1/20 to 3 in atomic ratio and light energy is concentrated on the ultraviolet region of the wavelength ranging of from 280 to 420 [nm] (claim of Japanese examined patent publication).
[0011] The patent literature 3 discloses a metal vapor discharge lamp including an arc tube into which an iron, a tin and a halogen are sealed in addition to mercury and a rare gas. In this metal vapor discharge lamp, silver is added in addition to the above-described iron and tin. When the quantities of the iron, the tin, the silver and the halogen sealed into the arc tube are respectively expressed as [Fe], [Sn], [Ag] and [J] by an atom gram number, these quantities are selected so as to satisfy ([Fe]+[Sn])/[J]<0.5 and (2[Fe]+2[Sn]+[Ag])/[J]>1 (claim for patent).
[0012] The patent literature 4 discloses a metal vapor discharge lamp including an arc tube into which mercury, a rare gas, a halogen and, at least, more than one kind of metals of groups of an iron, cobalt and a nickel are sealed as luminescent materials. In this metal vapor discharge lamp, the quantities of the metals sealed into the arc tube except the mercury are selected so as to satisfy A×D×V+B (A represents a reciprocal number of a valence of the metal sealed into the arc tube, D represents a density of halogen sealed into the arc tube, this density being selected so as fall within the range of 1×10 −5 to 1×10 4 mol/cm 3 , V represents an interval volume in cm 3 of the arc tube and B represents a constant ranging of from 0.7×10 −4 to 3.6×10 −4 mol) (claim for patent).
[0013] The patent literature 5 discloses a metal vapor discharge lamp including an arc tube into which an iron is sealed as a main luminescent metal element and iodine is sealed as halogen. This metal vapor discharge lamp aims to increase emission intensity of light with a wavelength ranging from 450 to 500 nm without lowering starting performance (Abstract, paragraph [0008]). An argon gas is sealed into the arc tube as a starting rare gas and a partial pressure thereof is selected in a range of 5 to 10 [torr] (Abstract, paragraph [0020]). At least mercury is sealed into the arc tube thereof as a buffer gas, an iron is sealed into the arc tube thereof as a luminescent metal, iodine and bromine are sealed into the arc tube thereof as a halogen and a rare gas is sealed into the arc tube thereof as a starting gas. When (I) represents the sealed atom number of iodine per internal volume of the arc tube and (Br) represents the sealed atom number of bromine per internal volume of the arc tube, the quantity (Br)+(I) falls within the range of 2×10 −7 to 14×10 −7 (mol/cc) and the atomic ratio expressed by (Br):(I) falls within the range of 0:90 to 30:70 (claim 1 ).
[0014] Having compared these citations with the present invention simply, we may have the following compared results.
[0015] The patent literature 1 discloses only the metal vapor discharge lamp into which a halogen of a predetermined quantity and an iron of a quantity of ½ to 3 times the quantity of the halogen in atomic ratio are sealed.
[0016] The patent literature 2 discloses only the metal vapor discharge lamp into which a halogen of the predetermined quantity and the total quantity of iron and tin of ½ to 3 times the quantity of the halogen are sealed in atomic ratio.
[0017] The patent literature 3 discloses the iron, the tin, the silver and the halogen sealed into the lamp. Further, this patent literature has specified the quantities of the iron, the tin, the silver and the halogen.
[0018] The patent literature 4 discloses only the discharge lamp in which the required quantities of metals sealed into the lamp except mercury are specified in relation to the quantity of halogen.
[0019] The patent literature 5 aimed to increase the intensity of illumination of light with a wavelength ranging from 450 to 500 [nm], having observed starting performance. A pressure of an argon gas available as a starting rare gas is lowered in the range of 5 to 10 [torr] to thereby cancel deteriorated starting performance out. This patent literature is characterized by a wavelength of light and a pressure of a rare gas which are different from those of the inventive examples which will be described below. Further, having observed a quantity of an iron sealed into the lamp, it is to be noted that a quantity of (Fe) is selected in the range of 6×10 −7 [mol/cc], a quantity of (Sn) is selected in the range of 2×10 −7 [mol/cc] and a quantity of (I)+(Br) is selected in the range of 8×10 −7 [mol/cc] in the inventive example 1. Based on these numerical values, it is clear that (Fe) and (Sn) exist as iron halides and tin halides. Also, while the tin is merely replaced with a lead in the second inventive example, the tin or the iron is merely replaced with the iron in the third inventive example so that a relationship between the quantity of the metal and the quantity of the halogen is not changed at all. Accordingly, this patent literature is different from the present invention in which the quantity of the metal iron is increased independently of the quantity of the iron halides.
SUMMARY OF INVENTION
Technical Problem
[0020] The present invention is intended to provide a metal halide lamp for irradiating light of ultraviolet rays to cause a photochemical reaction for use in a drying process of inks and paints and a curing process of resins and the like. While a spectrum of light with a wavelength of 100 to 400 [nm] is generally referred to as light of ultraviolet rays, the present invention is intended to provide a metal halide lamp which can produce intense light of ultraviolet rays with a spectrum of, particularly, a wavelength ranging from 350 to 380 [nm] (the above light of ultraviolet rays will hereinafter be referred to as “light of ultraviolet rays near a wavelength 365 [nm]” which is a central wavelength).
[0021] The applicant of the present invention has paid attention to an iron (Fe) available as an luminescent material in the research and development of metal vapor discharge lamps and has proposed a metal vapor discharge lamp into which a halogen of a predetermined quantity and an iron of a quantity of ½ to 3 times the quantity of the halogen are sealed in atomic ratio in the patent literature 1. Further, in the patent literature 2, the applicant of the present invention has proposed a metal vapor discharge lamp into which an iron and a tin are sealed into the lamp in such a manner that a total quantity of the iron and the tin are selected to be ½ to 3 times the predetermined quantity of the halogen in atomic ratio and that the quantity of the tin is selected to be 1/20 to 3 times the quantity of the iron in atomic ratio.
[0022] A metal halide lamp containing irons shows a tendency such that iron and tungsten (W) of electrodes may react to each other to damage and deteriorate the electrodes under high temperature circumstances in which an arc discharge occurs.
Solution to Problem
[0023] In view of the above-described problems, an object of the present invention is to provide a novel ultraviolet ray irradiation metal halide lamp which can produce more intense light of ultraviolet rays with a wavelength near 365 [nm].
[0024] A metal halide lamp of the present invention is a metal halide lamp for producing mainly light of ultraviolet rays, said metal halide lamp comprising a lamp into which a rare gas and at least mercury and an iron are sealed to produce light with a high spectrum in ultraviolet rays, particularly, light with a wavelength of 350 to 380 [nm], in which said iron is supplied by iron iodide (FeI 2 ) and iron bromide (FeBr 2 ) as iron halide (FeX 2 ) and metal iron (Fe), when a quantity of the sealed iron is expressed such that A represents a quantity of metal iron (Fe) sealed into the lamp, B represents a quantity of iron iodide (FeI 2 ) sealed into the lamp and that C represents a quantity of iron bromide (FeBr 2 ) sealed into the lamp, respectively, the quantity A of said metal iron (Fe) falls within the range of 0.5(B+C)≦A≦10.0(B+C) [mol/cm 3 ], the quantity (B+C) of said iron halide (FeX 2 ) falls within the range of 1.0×10 −7 ≦(B+C)≦4.5×10 −7 [mol/cm 3 ], and a ratio {C/(B+C)} of said iron bromide (FeBr 2 ) in said ion halide (FeX 2 ) falls within the range of {C/(B+C)}=5 to 70 [%].
[0025] Further, with respect to the above a metal halide lamp, said metal halide lamp may be characterized in that said quantity A of said metal iron (Fe) falls within the range of 0.5(B+C)≦A≦3.0(B+C) [mol/cm 3 ], said quantity (B+C) of said iron halide (FeX 2 ) falls within the range of 2.0×10 −7 ≦(B+C) 3.5×10 −7 [mol/cm 3 ], and said ratio {C/(B+C)} of said iron bromide (FeBr 2 ) in said iron halide (FeX 2 ) falls within the range of {C/(B+C)}=5 to 60 [%].
[0026] Further, with respect to the above a metal halide lamp, said metal halide lamp may further comprise an argon (Ar) gas of 2.0 [kPa] sealed therein as said rare gas.
[0027] Further in a method of manufacturing a metal halide lamp of the present invention, a rare gas and at least mercury and an iron being sealed into the lamp to produce light of ultraviolet rays with a high spectrum, particularly, light with a wavelength of 350 to 380 [nm], the sealed iron being offered by iron iodide (FeI 2 ) and iron bromide (FeBr 2 ) as metal halide (FeX 2 ) and metal iron (Fe), in the process to determine the composition of the luminescent material, a quantity A of the metal iron (Fe) being determined such that 0.5(B+C)≦A≦10.0(B+C) [mol/cm 3 ] is satisfied, a quantity (B+C) of the iron halide (FeX 2 ) being determined such that 1.0×10 −7 ≦(B+C)≦4.5×10 −7 [mol/cm 3 ] is satisfied and a ratio {C/(B+C)} of the iron bromide (FeBr 2 ) in the iron halide (FeX 2 ) being determined such that {C/(B+C)}=5 to 70% is satisfied, when a quantity of the sealed iron is expressed such that A represents a quantity of metal iron (Fe) sealed into the lamp, B represents a quantity of iron iodide (FeI 2 ) sealed into the lamp and C represents a quantity of iron bromide (FeBr 2 ) sealed into the lamp, respectively, said method of manufacturing a metal halide lamp comprising the steps of: manufacturing a quartz tube into a predetermined shape and connecting quartz pipes serving as electrode fixing portions to respective ends of the quartz tube of a central portion which serves as a light-emitting portion in an envelope manufacturing process; fixing electrodes to said quartz tube in a sealing process and a fusion-welding process; evacuating the inside of said quartz tube in an exhausting process and sealing the halide, the metal iron, mercury, the rare gas (argon gas, etc.) determined in the process to determine the composition of said luminescent material into said quartz tube and sealing an exhausting portion; and fixing bases to respective ends of said quartz tube in a finishing process.
Advantageous Effects of Invention
[0028] According to the present invention, it is possible to provide a novel ultraviolet-irradiation metal halide lamp which can produce more intense light of ultraviolet rays with a wavelength near 365 [nm]. Moreover, if this lamp is used, then it is possible to efficiently irradiate a liquid crystal material substance with light required by a photochemical reaction. Thus, it is possible to manufacture a highly efficient liquid crystal panel as compared with a prior-art liquid crystal panel.
BRIEF DESCRIPTION OF DRAWINGS
[0029] FIG. 1 is a schematic cross-sectional view of a metal halide lamp according to an embodiment of the present invention.
[0030] FIG. 2 is a graph showing measured results obtained when lumen maintenance factors of respective lamps were measured in the experiments to calculate a preferable quantity A of a metal iron (Fe) available as a luminescent material at the first stage.
[0031] FIG. 3 is a graph showing measured results obtained when the intensities of illumination of respective lamps were measured in the experiments to calculate a preferable quantity (B+C) of an iron halide (FeX 2 ) available as a luminescent material at the second stage.
[0032] FIG. 4 is a graph showing measured results obtained when lumen maintenance factors of respective lamps were measured in the experiments to calculate a preferable ratio {C/(B+C)} between an iron iodide (B) and an iron bromide (C) composing a preferable iron halide (FeX 2 ) available as a luminescent material at the third stage.
[0033] FIG. 5 is a flowchart to which reference will be made in explaining a method of manufacturing the lamp shown in FIG. 1 .
DESCRIPTION OF EMBODIMENTS
[0034] Embodiments of the present invention will hereinafter be described in detail with reference to the accompanying drawings. In the drawings, identical elements are denoted by identical reference numerals, respectively, and need not be described repeatedly. It should be noted that the embodiments of the present invention are used to explain the present invention by way of example and that these embodiments may not limit the scope of the present invention.
[Metal Halide Lamp]
[0035] A target metal halide lamp has physical sizes of its shape and the like which are identical to those of the lamp disclosed in the patent literature 4. FIG. 1 is a schematic cross-sectional view of this metal halide lamp 10 . This metal halide lamp includes a quartz arc tube 1 that has a pair of electrodes 2 , 2 provided within the arc tube. Each electrode includes an electrode tip end portion 2 a . This electrode tip end portion comprises an electrode stem made of a tungsten (W) or a thoriated tungsten containing a thorium of a quantity of approximately 2 [%] or an oxide-doped tungsten with a doped rare earth oxide and a tungsten wire wound around the electrode stem several times in a coil fashion. The respective electrodes 2 , 2 are connected to external lead wires through molybdenum foils 3 , 3 , respectively. The arc tube 1 is of a straight tube type and the inner diameter of the lamp tube is 20 mm, a distance between the electrodes (length of produced light) is 250 mm and an argon (Ar) gas of a pressure of 2.0 [kPa] (equivalent to approximately 15 [torr]) is sealed into the arc tube as a rare gas. Luminescent materials which are sealed into the arc tube will be described below.
[Compositions of Luminescent Materials]
[0036] Compositions of luminescent materials sealed into the lamp shown in FIG. 1 will be explained. A metal iron (Fe) and an iron halide (FeX 2 ) are used as luminescent materials. The iron halide, FeX 2 is made by a mixture of an iron iodide (FeI 2 ) and an iron bromide (FeBr 2 ).
[0037] In order to facilitate the explanation concerning the luminescent materials, respective elements will be marked below by symbols in which reference letter A represents a quantity of a metal iron (Fe) sealed into the lamp tube, B represents a quantity of an iron iodide (FeI 2 ) sealed into the lamp tube and C represents a quantity of an iron bromide (FeBr 2 ) sealed into the lamp tube. Accordingly, we may have the expression of an iron of luminescent material=metal iron (Fe)+iron halide (FeX 2 )=metal iron (Fe)+iron iodide (FeI 2 )+iron bromide (FeBr 2 )=A+B+C.
(First Stage: Studies on a Quantity of a Metal Iron Fe)
[0038] At the first stage, we have made experiments to obtain the preferable quantity A of the metal iron (Fe). To be concrete, under the condition that the iron of the luminescent material=metal iron (Fe)+Iron halide (FeX 2 )=A+(B+C) is satisfied, we have manufactured and evaluated a plurality of lamps while the quantity (B+C) of the iron halide was kept constant but the quantity A of the metal iron was being changed in the range of zero to 15 times the quantity (B+C) of the iron halide. A small quantity of a tin iodide (SnI 2 ) was used as an arc stabilizer. The iron halide may radically react with the tungsten (W) electrode under high temperature circumstances. In a like manner, the metal iron also may radically react with the tungsten (W) electrode. Accordingly, the preferable quantity A of the metal iron was evaluated by calculating time degradation characteristics of illuminance of the lamp.
[0000] TABLE 1 Time degradation characteristics of illuminance of lamp A/ C/ A B C B + C (B + C) (B + C) Sample Fe FeI 2 FeBr 2 FeX 2 Fe/ FeBr 2 / SnI 2 Nos. [mol/cm 3 ] [mol/cm 3 ] [mol/cm 3 ] [mol/cm 3 ] FeX 2 FeX 2 [mol/cm 3 ] 11 zero 2.0E−07 1.1E−07 3.1E−07 zero 0.365 0.20E−07 12 0.65E−07 0.2 13 1.5E−07 0.5 14 9.1E−07 3.0 15 31E−07 10.0 16 46E−07 15.0
Lamps used in experiments: metal halide lamp shown in FIG. 1
[0039] The table 1 shows data obtained from the respective lamps when the quantity (B+C) of the iron halide (FeX 2 ) sealed into the lamp was made constant while the quantities A of the metal iron (Fe) in the material sealed into the lamp were changed. The lamp used in the experiments is the lamp shown in FIG. 1 . It should be noted that the sample Nos. on the table 1 are denoted by a 10 number in order to avoid overlapping of samples used in other experiments.
[0040] There were prepared six kinds of sample Nos. 11 to 16 in which the quantity (B+C) of the iron halide (FeX 2 ) sealed into the lamp was made constant while the quantities A of the metal iron (Fe) sealed into the lamp were being changed in the range of zero to 46×10 −7 [mol/cm 3 ].
[0041] In order to calculate time degradation characteristics of illuminance of the lamp, illuminance of every sample was measured at a wavelength of 365 [nm] after elapse of time of zero, 500, 1000, 1500 and 2000 hours. The illuminance of those samples was calculated and obtained as relative values under the condition that illuminance obtained from each sample immediately after each sample was manufactured (without elapse of time) was set to 100 [%] (this illuminance will hereinafter be referred to as an “initial illuminance”). These relative values were set to lumen maintenance factor [%] obtained after each elapse of time. FIG. 2 is a graph showing the thus obtained lumen maintenance factors.
[0042] It is said that a metal halide lamp has a nominal lifetime of approximately 1,500 hours. The sample Nos. 14, 13 and 15 had lumen maintenance factor higher than 80 [%] of the initial illuminance after elapse of time of 1,500 hours. Illuminance of the sample Nos. 16, 12 and 11 was lowered to less than 80 [%] of the initial illuminance.
[0043] The sample No. 11 has the quantity A of the metal iron (Fe)=zero. The sample No. 12 has the smallest quantity A of the metal iron (Fe). The sample No. 16 has the largest quantity A of the metal iron (Fe).
[0044] In the first place, having compared the sample No. 11 (A=zero) and other samples (A≠zero) with each other, it became clear that samples which contain the quantity A of the metal iron in addition to the quantity (B+C) of the iron halide had higher lumen maintenance factor. Next, it became clear that lumen maintenance factor could be improved in the sample Nos. 12 to 14 in which the quantities A of the metal iron were increased, lumen maintenance factor of the sample No. 14 could reach the peak value and that lumen maintenance factor was lowered in the sample Nos. 14 to 16 in which the quantity A of the metal iron was further increased. This may be considered such that the peak value of the lumen maintenance factor lies between the sample Nos. 13 and 15 , i.e. the peak value of the lumen maintenance factor exists near the sample No. 14.
[0045] The reason that the lumen maintenance factor of the sample No. 11 is degraded comparatively rapidly may be considered in such a manner that, while the iron exists within the lamp tube as the iron halide (FeI 2 ), the iron halide radically reacts with the tungsten (W) of the electrode under high temperature circumstances to produce chemical compounds with the result that irons which contribute to the emission of light are lost with elapse of time. This is also true in the lamp of the sample No. 12. The reason for this may be considered such that, since the metal iron (Fe) of a very small quantity gradually reacts with the tungsten (W) of the electrode under high temperature circumstances, irons which may contribute to the emission of light are exhausted finally in a comparatively short period of time.
[0046] The quantity A of the metal iron (Fe) in the sample No. 16 corresponds to 15 times of the quantity (B+C) of the iron halide FeX 2 . It may be considered that, since the metal iron of the excessively large quantity and the tungsten (W) of the electrode react with each other under high temperature circumstances, the electrode itself is damaged with elapse of time so that arc discharge is hindered to deteriorate illuminance of the sample of the lamp.
[0047] A study of the results shown in FIG. 2 reveals that the preferable lamps are those which can maintain illuminance higher than 80 [%] of the initial illuminance after elapse of time of 1,500 hours from a standpoint of maintaining the intensity of illumination of the lamp. A study of the table 1 reveals that the ratio of the quantity A of the metal iron (Fe) sealed into the lamp relative to the quantity (B+C) of the iron halide FeX 2 sealed into the lamp should preferably fall within the range of A/(B+C)=0.5 to 10.0 which correspond to the sample Nos. 13, 14 and 15. The quantity A should preferably be selected so as to fall within the range of 0.5(B+C)≦A≦10.0(B+C) [mol/cm 3 ].
[0048] Further, the ratio of the quantity of the metal iron sealed into the lamp relative to the quantity of the iron halide sealed into the lamp should more preferably lie within the range of A/(B+C)=0.5 to 3.0 which correspond to the sample Nos. 13 and 14 that can maintain illuminance higher than 80 [%] of the initial illuminance even after elapse of time of 2,000 hours. The quantity A (quantity of metal iron) should be selected so to fall within the range of 0.5(B+C)≦A≦3.0(B+C) [mol/cm 3 ].
(Second Stage: Studies on Quantity of Iron Halide FeX 2 )
[0049] The preferable range of A (quantity of metal iron) became clear in the first stage. At the second stage, we have made experiments to calculate preferable quantities (B+C) of the iron halide (FeX 2 ) available as a preferable luminescent material within the range of the quantity A of the iron in the first stage.
[0050] Concretely, we have made the experiments with respect to the lamps in which the quantity A of the metal iron was kept constant but the quantity (B+C) of the iron halide was varied under the condition that an equality of irons in the luminescent material=metal iron (Fe)+iron halide (FeX 2 )=A+(B+C) is satisfied. At the same time, we have made the experiments on comparative examples of lamps in which case an iron halide is composed of only the iron iodide (FeI 2 ) (B only) and the iron halide is composed of a mixture (B+C) of the iron iodide (FeI 2 ) and the iron bromide (FeBr 2 ). A thallium iodide (TII) of a small quantity was used as an arc stabilizer.
[0051] The metal iron and the iron of the iron halide are sealed into the lamps as the luminescent material in order to improve illuminance of the lamp. Accordingly, an optimum quantity (B+C) of iron halide was evaluated based on measured results of illuminance of lamps.
[0000] TABLE 2 Illuminance characteristics concerning iron halide A/ C/ A B C B + C (B + C) (B + C) 365 nm Sample Fe FeI 2 FeBr 2 FeX 2 Fe/ FeBr 2 / TlI Illuminance Nos. [mol/cm 3 ] [mol/cm 3 ] [mol/cm 3 ] [mol/cm 3 ] FeX 2 FeX 2 [mol/cm 3 ] [%] 21 13E−07 0.78E−07 zero 0.78E−07 16.6 zero 0.183E−07 100 22 1.2E−07 1.2E−07 11.1 109 23 1.6E−07 1.6E−07 8.3 115 24 2.3E−07 2.3E−07 5.5 113 25 0.39E−07 0.22E−07 0.62E−07 21.1 0.365 107 26 0.78E−07 0.45E−07 1.2E−07 10.6 0.365 118 27 1.2E−07 0.67E−07 1.8E−07 7.02 0.365 127 28 1.6E−07 0.9E−07 2.5E−07 5.3 0.365 129 29 2.0E−07 1.1E−07 3.1E−07 4.2 0.365 126 30 2.4E−07 1.3E−07 3.6E−07 3.6 0.355 124 31 3.5E−07 2.1E−07 5.7E−07 2.3 0.377 88
Lamp used in experiments: Metal halide lamp shown in FIG. 1
[0052] The lamp used in the experiments is the lamp shown in FIG. 1 . In the sample Nos. 21 to 31 shown on the table 2, the quantity A of the metal iron (Fe) in the luminescent material is kept constant so as to satisfy an equality of A=13×10 −7 [mol/cm 3 ]. The value thus selected as the quantity A is nearly a mean value of the sample Nos. 13, 14 and 15 which may fall within the preferable range. Sample Nos. on the table 2 are denoted by a 20 number and a 30 number in order to avoid overlapping of samples of lamps in other experiments.
[0053] The sample Nos. 21 to 24 may utilize only the iron iodide as the iron halide (FeX 2 ) (iron iodide B only) but they did not use the iron bromide (FeBr 2 ). The sample Nos. 25 to 31 use a mixture (B+C) of iron iodide and iron bromide as the iron halide.
[0054] In the sample Nos. 21 to 24 which use only the iron iodide B, the quantity of the iron bromide B is gradually varied so as to increase in the range of 0.78×10 −7 to 2.3×10 −7 [mol/cm 3 ]. Similarly, in the sample Nos. 25 to 31 which use the mixture (B+C) of the iron iodide and the iron bromide, the quantity (B+C) is gradually varied to so as to increase in the range of 0.62×10 −7 to 5.7×10 −7 [mol/cm 3 ].
[0055] Illuminance of the lamps was measured by an illuminometer suitable for use in measuring light with a wavelength of 365 [nm]. Measured data are shown on the table in such a manner that illuminance of the sample No. 21 is set to 100 [%] and that other measured data are shown thereon as relative values.
[0056] FIG. 3 is a graph showing measured results of illuminance of those samples of lamps. Having compared the samples of (B only) and the samples of (B+C) with each other, it became clear that all data show that illuminance of the samples of (B+C) was higher than illuminance of the samples of (B only) when the quantities of the iron halides are the same.
[0057] With respect to illuminance of the samples in which the iron halide is composed of only the iron iodide (B only), a study of this graph reveals that illuminance of the sample Nos. 21 to 23 in which the quantities of the iron iodide are increased could be improved. However, illuminance of sample Nos. 23 to 24 in which the quantities of the iron iodide were increased more was lowered conversely. With respect to illuminance of samples of (B+C), illuminance of sample Nos. 25 to 28 in which the quantity of the iron halide was increased could be improved. However, illuminance of sample Nos. 28 to 31 in which the quantity of the iron halide was increased more was gradually lowered conversely. As described above, with respect to both of the samples of (B only) and the samples of (B+C), there is a tendency that illuminance of the samples could be improved by the increase of the quantity of the iron halide, they reached their peak values by the constant quantity of the iron halide and that they are lowered by more increasing the quantity of the iron halide.
[0058] The iron is the luminescent material within the lamp. Accordingly, it might be considered that illuminance of the sample Nos. 21 to 23 and the sample Nos. 25 to 28 could be improved with the increase of the iron halide (FeX 2 ). On the other hand, illuminance of the sample Nos. 23 to 24 and the sample Nos. 28 to 31 was gradually lowered as the quantity of the iron halide is increased. The cause that illuminance of the samples was gradually lowered as the quantity of the iron halide was increased might be considered such that the peak value of illuminance was deviated from the wavelength of 365 [nm] and moved to other wavelengths.
[0059] A maximum value of relative illuminance of the lamp of (B only) lies near B=1.8×10 −7 [mol/cm 3 ] and it is nearly 115 [%]. Accordingly, in order to obtain the benefits provided by the lamp of (B+C) in comparison with the lamp (B only), relative illuminance of the lamp of (B+C) should preferably be selected so as to become higher than 115 [%]. A study of FIG. 3 reveals that illuminance of the lamp of (B+C) should preferably be selected so as to fall within the range of 1.0×10 −7 ≦(B+C)≦4.5×10 −7 [mol/cm 3 ]. On the table 2, data surrounded by the open rectangles along the (B+C) column of the sample Nos. 26 to 30 may correspond to the above-mentioned data. Further, relative illuminance of the lamp should more preferably be selected so as to fall within the range of 2.0×10 −7 ≦(B+C)≦3.5×10 −7 [mol/cm 3 ] in which relative illuminance is higher than 125 [%].
(Third Stage: Studies on Ratio of Iron Bromide (FeBr 2 ) in Iron Halide (FeX 2 ))
[0060] The preferable range of the quantity A of the metal iron became clear at the first stage and the preferable range of the quantity (B+C) of the iron halide became clear at the second stage.
[0061] At the third stage, we have made the experiments to calculate a preferable ratio between the iron iodide (B) and the iron bromide (C) composing the iron halide (B+C) within the range of the quantity A ascertained at the first stage and within the range of the quantity (B+C) of the iron halide ascertained at the second stage. Concretely, we have made the experiments on respective lamps in which, under the condition that an equality of iron of material sealed into the lamp=metal iron (Fe)+iron halide (FeX 2 )=A+(B+C) was satisfied, the quantity A and the quantity (B+C) were kept substantially constant within the ranges ascertained at the first and second stages and the ratio {C/(B+C)} of C relative to the quantity (B+C) was changed.
[0062] Irons of the metal iron (Fe) and the iron halide (FeX 2 ) are sealed into the lamp in order to improve illuminance of the lamp. On the other hand, the metal iron and the iron halide react with the tungsten (W) electrode. Accordingly, the preferable ratio {C/(B+C)} of the quantity of the iron bromide relative to the quantity of the iron halide was evaluated based on both standpoints of illuminance of the lamp and lumen maintenance factor.
[0000] TABLE 3 Illuminance characteristics and time degradation characteristics of lamps A/ C/ A B C B + C (B + C) (B + C) Sample Fe FeI 2 FeBr 2 FeX 2 FeBr 2 / SnI 2 Illuminance Nos. [mol/cm 3 ] [mol/cm 3 ] [mol/cm 3 ] [mol/cm 3 ] Fe/Fx 2 FeX 2 [%] [mol/cm 3 ] [%] 41 9.1E−07 3.1E−07 zero 3.1E−07 3.0E−07 zero 0.52E−07 100 42 2.9E−07 0.11E−07 3.0E−07 3.7 102 43 2.9E−07 0.17E−07 3.1E−07 5.5 116 44 2.3E−07 0.67E−07 3.0E−07 22.3 117 45 2.0E−07 1.1E−07 3.1E−07 36.5 119 46 1.4E−07 1.1E−07 3.1E−07 55.2 118 47 1.0E−07 2.1E−07 3.2E−07 2.9E−07 67.7 119 48 7.8E−07 2.2E−07 3.0E−07 3.0E−07 74.2 118
Lamp used in experiments: metal halide lamp shown in FIG. 1
[0063] The lamp used in the experiments is the lamp shown in FIG. 1 . Based on the table 1 at the first stage and (the studies on the metal iron Fe) shown in FIG. 2 , it became clear that the quantity A should preferably be selected so as to fall within the range of 0.5(B+C)≦A≦10.0(B+C) [mol/cm 3 ]. Further, based on the table 2 at the second stage and (the quantity of the iron halide FeX 2 ) shown in FIG. 3 , it became clear that the quantity (B+C) should preferably be selected so as to fall within the range of 1.0×10 −7 ≦(B+C)≦4.5×10 −7 [mol/cm 3 ]. At this third stage, the quantity A of the metal iron is made substantially constant such as 9.1×10 −7 [mol/cm 3 ] within the range calculated at the first stage. The quantity (B+C) of the iron halide also is made substantially constant such as 3.0×10 −7 to 3.2×10 −7 [mol/cm 3 ] within the range calculated at the second stage. On the table 3, data encircled by open rectangles in the column of A and the column of (B+C) correspond to the above quantity of the metal iron and the above quantity of the iron halide.
[0064] Under this condition, the ratio {C/(B+C)} of the quantity of the iron bromide relative to the quantity of the iron halide is gradually changed in the range of zero to 74.2 [%]. A tin iodide (SnI 2 ) of a small quantity is utilized as an arc stabilizer. It should be noted that sample Nos. on the table 3 are denoted by a 40 numbers in order to avoid overlapping of the samples in other experiments.
[0065] Illuminance data were measured by the illuminometer suitable for use in measuring light of a wavelength 365 [nm]. With respect to illuminance data, illuminance of the sample No. 41 which does not contain the iron iodide C is selected to be 100 [%] and illuminance data of the respective lamps are indicated by relative values.
[0066] When samples are evaluated, initial illuminance should have a significant difference relative to a sample No. 41, i.e. illuminance should preferably be increased more than 10 [%]. Excepting sample No. 42, samples Nos. 43 to 48 might satisfy this condition. Based on these samples, it became clear that the ratio of the quantity of the iron bromide relative to the quantity of the iron halide should preferably be selected so as to fall within the range of substantially {C/(B+C)}≧5 [%].
[0067] Next, in order to obtain time degradation characteristics of illuminance, illuminance of any sample was measured after elapse of time of zero, 500, 1000, 1500 and 2000 hours and relative values were calculated under the condition that the initial illuminance of each sample was set to 100 [%], whereafter these calculated relative values were obtained as lumen maintenance factor [%] per elapse of each time. FIG. 4 is a graph showing these lumen maintenance factors.
[0068] A study of the results shown in FIG. 4 reveals that preferable lamps are those which can maintain more than 80 [%] of the initial illuminance after elapse of time of 1,500 hours from a standpoint of maintaining illuminance of the lamp. From FIG. 4 , it became clear that the sample Nos. 44, 45, 43, 46 and 47 could satisfy the conditions of these lamps. Based on the table 3, it became clear that the quantities {C/(B+C)} of these sample Nos. 43 to 47 should preferably be selected so as to fall within the range of {C/(B+C)}=5 to 70 [%]. These samples should satisfy the conditions by which illuminance of the above-mentioned sample No. 41 could be improved more than 10 [%].
[0069] Further, referring to FIG. 4 , it is to be understood that the sample Nos. 44, 45, 43 and 46 which can maintain more than 80 [%] of the initial illuminance after elapse of time of 2,000 hours should be more preferable. From the table 3, it became clear that the ratio of the iron iodide relative to the iron halide should be more preferably selected so as to fall within the range of {C/(B+C)}=5 to 60 [%] of the sample Nos. 43 to 46.
[0070] The sample Nos. 41 and 42 in which the ratio of {C/(B+C)} is zero or very small had no significant difference for the initial illuminance as described above and lumen maintenance factors thereof also were low. Based on these results, it became clear that when the ratio of {C/(B+C)}=zero, that is, when the iron halide is made of only the iron iodide (B only), as compared with the case of (B+C), lumen maintenance factors thereof were low at the third stage in addition to the fact that the initial illuminance thereof was low as was clear from the second stage. The samples in which the ratios of {C/(B+C)} are very small have the same tendency.
[0071] The sample Nos. 43 to 45 in which the ratio of {C/(B+C)} was increased gradually could improve initial illuminance such as initial illuminance of 116, 117, 119 [%] progressively as shown on the table 3 so that lumen maintenance factors thereof could be improved as shown in FIG. 4 . However, sample Nos. 45 to 48 in which the ratio of {C/(B+C)} had further been increased reached the peak values thereof and lumen maintenance factors thereof also were lowered. That is, it became clear that, when the iron halide is composed of the mixture of the iron iodide and the iron bromide, the optimum peak value of the ratio {C/(B+C)} of the iron bromide relative to the quantity of the iron halide lies near the range of {C/(B+C)}=35 to 55 [%] which might cover the sample Nos. 45 and 46.
[0072] It became clear that, when the iron halide is composed of only the iron iodide (B only), resultant lamps should be inferior to those lamps composed of the mixture (B+C) of the iron halide of the iron iodide and the iron bromide from both of initial illuminance and lumen maintenance factor. Further, it became clear that good results of both of illuminance and lumen maintenance factor could be obtained by increasing the quantity of the iron bromide up to a certain quantity. However, since the iron bromide (FeBr 2 ) is relatively high in reactivity as compared with the iron iodide (FeI 2 ), if the iron bromide has an excessively large ratio in the iron halide, then such iron bromide can easily react with the tungsten (W) electrodes, thereby to lower lumen maintenance factor.
[Manufacturing Method of Metal Halide Lamp]
[0073] A method of manufacturing this metal halide lamp will be described with reference to FIG. 5 .
[0074] In a process for manufacturing an envelope of a lamp at a step S 1 , a quartz tube (depicted by reference numeral 1 in FIG. 1 ) is manufactured as a quartz tube of a desired shape. Quartz tubes that may serve as electrode fixing portions are connected to respective ends of the quartz tube 1 at its central portion which serves as a light-emitting portion of a lamp. A thin pipe (exhaust pipe) that serves both as a conduit to introduce a sealed material into the quartz tube and which serves also as an exhausting conduit within the quartz tube is connected in advance to the quartz tube at its central portion in the direction perpendicular to the quartz tube by fusion-welding (not shown).
[0075] In a temporary exhausting process at a step S 2 , the electrodes are sealed into the envelope and the envelope was evacuated, whereafter an inert gas such as an argon gas of a very small pressure was sealed into the envelope.
[0076] In a sealing process and a fusion-welding process at a step S 3 , the electrodes 2 , 2 are fixed to the quartz tube.
[0077] In an exhausting process at a step S 4 , after the arc tube 1 was evacuated, halides and metal irons having predetermined compositions which will be described next and other elements such as mercury and a rare gas (argon gas, etc.) are sealed into the quartz tube and the exhaust pipe is sealed by a tipoff. Here, a high-purity iron reagent is used as the metal iron.
[0078] With respect to the iron and the iron halide sealed into the arc tube at this stage, the quantity A of the metal iron is determined so as to fall within the range of 0.5(B+C)≦A≦10.0(B+C) [mol/cm 3 ] at the above-mentioned first stage, the quantity (B+C) of the iron halide is determined so as to fall within the range of 1.0×10 −7 ≦(B+C)≦4.5×10 −7 [mol/cm 3 ] at the second stage and the preferable ratio {C/(B+C)} of the quantity C of the iron bromide (FeBr 2 ) relative to the quantity B of the iron iodide comprising the iron halide is determined so as to fall within the range of {C/(B+C)}=5 to 70% at the third stage.
[0079] In a finishing process at a step S 5 , bases are fixed to the respective ends of the quartz tube 1 .
Advantageous Effects of Invention
[0080] (1) Through the experiments at the first stage, the preferable quantity A of the metal iron (Fe) could be determined as a sealed material with respect to irons which are luminescent materials. This quantity should preferably be selected so as to fall within the range of 0.5(B+C)≦A≦10.0(B+C) [mol/cm 3 ]. More preferably, this quantity should be selected so as to fall within the range of 0.5(B+C)≦A≦3.0(B+C) [mol/cm 3 ]
[0081] (2) Through the experiments at the second stage, illuminance of the lamp could be improved by adding the iron halide FeX 2 to the metal iron Fe to thereby increase the quantity of the iron as the luminescent material. That is, it became clear that illuminance of the lamp of (B only) and illuminance of the lamp of (B+C) could be improved by increasing the quantity of the iron halide, illuminance of the lamp could reach the peak value by a certain quantity of iron halide and that illuimance of the lamp tends to be lowered by further increasing the quantity of the iron halide more.
[0082] (3) Through the experiments at the second stage, illuminance of the lamp of (B only) and illuminance of the lamp of (B+C) were compared with each other. When the quantity of the iron halide (FeX 2 ) is the same, it became clear that illuminance of the lamp of (B+C) was higher than that of lamp of (B only).
[0083] (4) Through the experiments at the second stage, under the condition of the preferable quantity A of the metal iron (Fe) obtained at the first experiment, there could be determined the preferable quantity (B+C) of the iron halide (FeX 2 ).
[0084] This preferable quantity of the metal iron should preferably be selected so as to fall within the range of 1.0×10 −7 ≦(B+C)≦4.5×10 −7 [mol/cm 3 ]. This quantity should more preferably be selected so as to fall within the range of 2.0×10 −7 ≦(B+C)≦3.5×10 −7 [mol/cm 3 ].
[0085] (5) Through the experiments at the third stage, the lamp in which the iron halide is composed of only the iron iodide (B only) and the lamp in which the iron halide is composed of the mixture of the iron iodide and the iron bromide (B+C) were compared with each other. It became clear that the lamp in which the iron halide is composed of the mixture of the iron iodide and the iron bromide (B+C) is superior in lumen maintenance factor to the lamp in which the iron halide is composed of only the iron iodide (B only).
[0086] (6) Through the experiments at the third stage, there could be determined the preferable ratio {C/(B+C)} between the quantity B of the iron iodide (FeI 2 ) and the quantity C of the iron bromide (FeBr 2 ) comprising the iron halide (FeX 2 ).
[0087] This ratio should preferably be selected so as to fall within the range of {C/(B+C)}=5 to 70 [%]. This ratio should more preferably be selected so as to fall within the range of {C/(B+C)}=5 to 60 [%].
[0088] By determining the compositions of the sealed materials on the basis of the data concerning the quantities of the luminescent materials obtained from the above-mentioned experiments and stages (1) to (6), it became possible to manufacture a metal halide lamp for irradiating light of ultraviolet rays to cause a photochemical reaction and of which initial illuminance and lumen maintenance factor are high when light of ultraviolet rays has a wavelength of 350 to 380 [nm]. Moreover, since this wavelength region is such one that is most effective for causing a photochemical reaction to form a liquid crystal orientation, it becomes possible to manufacture a liquid crystal panel which can efficiently irradiate the material of the liquid crystal with light and which can realize more sufficiently accurate high-definition images than those of the prior-art.
Modified Example and Summary
[0089] While the examples of the metal halide lamp according to the present invention have been described so far, these examples are described by way of example and may not limit the scope of the present invention. Changes easily made on the present invention by those skilled in the art, such as addition, deletion modification and improvement may fall within the scope of the present invention.
[0090] For example, in the above-mentioned embodiments, the range of the preferable quantity A of the metal iron was calculated at the first stage. At the second stage, the range of the preferable quantity (B+C) of the iron halide was calculated under the condition of the preferable quantity A obtained in the first stage. At the third stage, under the condition of the range of the quantity A and the range of the quantity (B+C) obtained in the second and third stages, the range of the ratio {C/(B+C)} of the quantity C of the iron bromide relative to the preferable quantity (B+C) of the iron halide was calculated. The scope of the present invention is not limited to the decisions of this order.
[0091] When the range of the preferable quantity (B+C) and the range of the ratio {C/(B+C)} are determined, the range of the quantity (B+C) is determined first and the ratio {C/(B+C)} is determined next from a time standpoint. However, the order in which the range of the quantity A and the range of the quantity (B+C) are determined may not be limited to the above-mentioned one and it may be changed freely. In the patent literature 1, the applicant of the present invention has proposed the metal vapor discharge lamp into which a halogen of a predetermined quantity and “iron” of a quantity ½ to 3 times the quantity of the halogen in atomic ratio are sealed. Based on this experience, the range of the quantity (B+C) can be determined while the quantity A of the iron is being made constant.
[0092] Accordingly, if the order that has been described so far in the above-mentioned embodiments is selected as the order to determine the first luminescent material, the present invention is not limited thereto and the following second and third modified examples are made possible.
[0093] 1. Second order to decide the first luminescent material
(first stage) the quantity A is made constant and the range of the quantity (B+C) is determined; (second stage) the quantity (B+C) is made constant and the range of the quantity A is determined; and (third stage) the quantity A and the quantity (B+C) are made constant and the range of the ratio {C/(B+C)} is determined.
[0097] 2. Third order to decide the first luminescent material
(first stage) the quantity A is made constant and the range of the quantity (B+C) is determined; (second stage) the quantity A and the quantity (B+C) are respectively made constant and the range of the ratio {C/(B+C)} is determined; and (third stage) the quantity (B+C) and the ratio (C/(B+C)) are respectively made constant and the range of the quantity A is determined.
[0101] The technical scope of the present invention may be determined based on the descriptions of the scope of the appended claims.
REFERENCE SIGNS LIST
[0102] 1 : arc tube, 2 : electrode, 2 a : electrode tip end portion, 3 : molybdenum foil, 10 : metal halide lamp,
[0103] A: quantity of metal iron (Fe) sealed into lamp, B: quantity of iron iodide (FeI 2 ) sealed into lamp, C: quantity of iron bromide (FeBr 2 ) sealed into lamp
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The present invention is to provide a novel ultraviolet irradiation metal halide lamp which can produce more intense light of ultraviolet region with a wavelength near 365 [nm]. This lamp is a metal halide lamp to produce mainly light of ultraviolet region. In order to produce light with a high spectrum in ultraviolet region, particularly, light of a wavelength of 350 to 380 [nm], at least mercury (Hg) and an iron are sealed into this lamp together with a rare gas. The sealed iron into the lamp is supplied by iron iodide (FeI 2 ) and iron bromide (FeBr 2 ) as iron halide (FeX 2 ) and metal iron (Fe). When a quantity of materials sealed into the lamp is expressed such that A represents a quantity of metal iron sealed into the lamp, B represents a quantity of iron iodide sealed into the lamp and C represents a quantity of iron bromide sealed into the lamp, respectively, the quantity A of the metal iron falls within the range of 0.5(B+C)≦A≦10.0(B+C) [mol/cm 3 ], the quantity (B+C) of the iron halide falls within the range of 1.0×10 −7 ≦(B+C)≦4.5×10 −7 [mol/cm 3 ] and a ratio {C/(B+C)} of the iron iodide (FeBr 2 ) in the iron halide (FeX 2 ) falls within the range of {C/(B+C)}=5 to 70%.
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This application is a continuation-in-part of U.S. patent application Ser. No. 694,820 filed Jan. 25, 1985 now abandoned.
This invention relates to a new and improved support assembly for adjustably positionally supporting a tube in spaced relation from a supporting surface, and, more particularly, to a tube support assembly adapted for adjustably mounting lighting tubes of the kind commonly employed in neon signs to position the tubes in a desired spaced relation from other elements of the signs.
BACKGROUND OF THE INVENTION
Illuminated tubular lighting of the neon tube type is well known and has been employed for many years in advertising display signs and other decorative lighting. Typically, such neon signs are constructed of a support frame on which may be mounted a back display panel and variously contoured or configured neon illuminating glass tubing. The glass tubing is generally supported in spaced relation from the support frame and back panel by a plurality of short, stand-off elements attached to and extend outwardly from the sign frame at spaced locations along its length. Generally, the tubing is secured to the support elements by a wire tie, or certain of the elements are constructed with a C-shaped clamp portion which engages and retains the tubing. Generally, the stand-off supports are attached to the sign support frame or the back panel by welding, rivots, or threaded fastening elements, such as screws or bolts, received in suitable openings in the back panel or frame.
It has also been known to provide spring members in the tube supports between the support frame and the tube itself to provide a force-dampening effect to protect against tube breakage in shipping and handling of the signs, and to provide a degree of lengthwise adjustment of the support elements to accomodate for uneveness in tubing and/or support frame dimensions and separation distances.
Since the luminous tubing of neon display signs is variously shaped, curved, and bent to provide desired lettering or other special artistic configurations in the sign, it is desirable to provide a degree of adjustability of the tube support elements to position them in the proper location and spacing on the sign frame to correctly support the tubing thereon. A number of luminous tube support constructions for mounting tubing on supporting surfaces are disclosed in the following U.S. Pat. Nos.: 1,822,980 Palmer, 2,545,416 Staaf, 2,629,814 Brown, 2,885,538 Mahon et al., 3,135,488 Leonard, 4,201,004 Witt.
BRIEF OBJECTS OF THE PRESENT INVENTION
It is an object of the present invention to provide a new and improved tube support assembly for adjustably positioning and supporting a tube in spaced relation from a supporting surface.
It is another object to provide an adjustable tube support assembly which may be readily attached to a supporting surface and to tubing to be supported, without the necessity of additional fastening elements or special adaptation of the supporting surface to receive the assembly.
It is a further object to provide a tube support assembly having improved positional adjustability from a supporting surface to receive and support a tube at various positions therefrom.
It is a more specific object to provide an improved support assembly for adjustably positionally supporting glass tubing of a neon sign from the support frame thereof, wherein the support assembly receives the tubing and the support frame of the sign in frictional snap-fit relation therewith.
It is still a further object to provide an improved support assembly for tubing which is of economical construction and composed principally of molded plastic parts which may be easily and quickly assembled in snap-fit relation with each other to provide for positional adjustability of the same in use.
It is another object to provide a support assembly for adjustably positionally supporting a glass tube of a neon sign while permitting movement of the tube in multiple directions to reduce breakage of the tube which may be caused by shock forces applied to the sign in handling, shipping or use.
BRIEF DESCRIPTION OF THE DRAWINGS
The above as well as other objects of the present invention will become more apparent, and the invention will be better understood from the following detailed description of preferred embodiments thereof, when taken together with the accompanying drawings in which:
FIG. 1 is a schematic perspective view of a tube support assembly of the present invention supportably attached to a rod-shaped element support of the frame of a neon sign, with a portion of glass tubing supported C-clamp in the assembly;
FIG. 2 is a end view of the assembly of FIG. 1;
FIG. 3 is a side view of the assembly of FIG. 1, with the clamp post of the assembly compressed into the support column;
FIG. 4 is a fragmentary side view of the base of the assembly of FIG. 1, showing the shape of the side wall of the channel of the base when removed from the frame support element of the sign;
FIG. 5 is an enlarged end view of the assembly of FIG. 1, with portions in vertical section to show the interior of the assembly; and
FIG. 6 is an enlarged end view of another embodiment of the assembly of FIGS. 1-5, with portions in vertical section to show the interior of the assembly.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Referring more particularly to the drawings, the adjustable tube support assembly 10 of the present invention generally comprises a base 12, a tubular column 14 pivotally mounted on the base, and a clamp post 16 telescopically received in the tubular column. The base, tubular column and clamp post are preferably molded of suitable high strength plastic, such as polystyrene.
As seen in the figures, the base 12 of the assembly has an overall generally rectangular shape. On the bottom side of the base, as seen, are a pair of spaced, inwardly tapering wall sections 18 defining an open-ended elongate channel 20 for grippingly engaging a typical generally rectangular rod-shaped element 22 of a supporting frame of a neon display sign (not shown). A continuous wall portion 26 on the top side of base 12 forms a generally semi-spherical socket 28 which communicates with the channel 20 to form an opening through the base from side to side.
As illustrated in FIGS. 3 and 4, the inwardly tapering wall portions 18 are resiliently deformable to receive the rod-shaped element 22 of the neon sign frame in channel 20 in snap-fit relation therewith. Correspondingly, outer edges of the wall portion 26 forming the semi-spherical socket 28 are resiliently deformable to receive a ball-shaped base portion 30 of tubular column 14 in snap-fit relation therewith.
As seen in FIG. 5, tubular column 14 has an open, upper end 32 and a passageway extending therethrough to a lower opening in the bottom of the ball-shaped portion 30 of the column. The upper portion 32a of the column passageway is of uniform diameter, while the lower portion 32b is of a reduced diameter forming with the upper diameter portion a shoulder 34 in the passageway.
Telescopically received within the upper end of column 14 for movement in the passageway along the longitudinal axis of the column (note FIGS. 2 and 3) is an elongate lower portion 36 (FIG. 5) of the clamp post 16. The upper end of the clamp post is formed as a resiliently deformable generally C-shaped clamp 38 for receiving and frictionally retaining a glass illuminating tube 40 therein. The internal lower surface of the clamp 38 has a transversally bevelled surface 38a (FIGS. 3 and 5) to accomodate and support a glass tube at angles other than normal to the longitudinal axis of the clamp post, when required.
As seen in FIG. 5, the lower portion 36 of the clamp post is of reduced diameter from that of an upper portion 42 of the post to form a radial shoulder 44. The lower portion 36 of the post terminates in an enlarged diameter end portion 46. The enlarged end 46 of the post has a conically-shaped recess 48 to facilitate its resilient deformation, for purposes to be explained.
As also seen in FIG. 5, support assembly 10 further includes a metal spring 50 which resides in the column passageway in surrounding relation to the lower portion 36 of clamp post 16. Spring 50 is retained in position in the column passageway by means of two larger diameter metal rings 52, 54 which are frictionally received over the resilient, enlarged diameter end 46 of the clamp post in engagement with the upper and lower ends of the spring. Upper ring 52 engages and is retained by the post shoulder 44, while the lower ring 54 engages and is retained by the upper edge surface of the enlarged diameter end 46 of the post and the column passageway shoulder 34. The rings 52, 54 thus retain the ends of the spring on reduced diameter portion 36 of the post as the clamp post is moved against the force of the spring up or down along the axis of the column passageway.
The spring 50, rings 52, 54, and lower portion 36 of clamp post 16 are retained against removal from the tubular column passageway by a metal wire coil insert 60 which is of slightly larger outside diameter than the internal diameter of the upper portion of the column passageway and is press-fit to be frictionally secured therein.
The parts of the tube support assembly 10 may be readily assembled and interconnected for use, as follows:
Retaining coil 60, upper ring 52, spring 50, and lower ring 54 are received, in the order listed, over the enlarged end 46 and onto the lower portion 36 of clamp post 16. The end of the clamp post containing the assembled components is then inserted into the upper end of the tubular column passageway. The retaining coil insert 60 is press-fit into the upper end of the column 12 by suitable force-applying means to secure the rings 52, 54, spring 50 and clamp post 16 in the column passageway. The lower ball-shaped portion 30 of column 14 is then snap-fit into the semi-spherical socket 28 of base 12. The resilient walls 18 forming the base channel 20 can then be snap-fit about a rod-shaped support element of the support frame of a neon sign.
Tubular column 14 containing the clamp post 16 with its C-shaped clamp 38 may be pivoted in the base socket 28 within a 360° circle of movement to be located for receipt and support of a glass tubing. The support assembly 10 may be easily attached to rod support elements of a sign frame in any position, as desired, to supportably engage glass tubing, and without the necessity of additional fastening means, holes, recesses, or openings in the frame support elements to attach the assembly thereto.
In operation, the C-clamp 38 can move in either direction along the longitudinal axis of the tubular column against the tension and compression forces of the spring to accomodate and grippingly support glass tubing. As seen, engagement of lower ring 54 with the column shoulder 34 prevents movement of the lower end of the spring downwardly in the column when the post 16 moves downwardly. Engagement of the upper ring 52 with clamp post shoulder 44 and retaining coil 60 prevents movement of the upper end of the spring upwardly in the column as the post 16 moves upwardly, thus providing a biasing force against movement of the C-clamp in either direction along the longitudinal axis of the column. Such an arrangement permits lengthwise adjustment of the support assembly to accomodate a desired position of the glass tubing, while also serving to reduce breakage of the glass tubing by dampening and absorbing the shock effect of any forces applied against the neon sign frame.
FIG. 6 shows a further embodiment of the assembly of FIG. 1. Like parts of the support assembly of FIG. 6 to those shown in FIGS. 1-5 are indicated by prime numerals. Except as indicated hereinafter, the constructions are substantially identical.
The assembly of FIG. 6 includes C-shaped clamp post 16' receivable within tubular column 14', the ball-shaped lower portion 30' of which resides within the semi-spherical socket 28' of the base 12'. Located within the tubular column passageway in surrounding relation to clamp post 16' is metal wire coil insert 60' which frictionally engages the inner wall portion of the tubular column 14' to be retained therein. The column passageway includes radially inwardly extending shoulder 34'. In the embodiment of FIG. 6, the metal retaining rings 52, 54 shown in the embodiment of FIGS. 1-5 are omitted, and coil portions 72a, 72b at each end of spring 72 surrounding clamp post 16' are of slightly reduced diameter. As seen, coil portion 72a thus is dimensioned to engage with the retaining coil insert 60' and clamp post shoulder 44', while coil portion 72b is dimensioned to engage with column passageway shoulder 34' and the enlarged end portion 46' of post 16' during portions of movement of the post to retain the spring on the clamp post. The reduced diameter end portions of the spring 72 thus function as do the metal rings 50, 54 of the assembly of FIGS. 1-5 to restrain movement of respective ends of spring 72 during inward and outward movement of the C-clamp post in the tubular column and to resist removal of the clamp post 16' from the column. During assembly, the retaining coil 60' is received on the clamp post 16', the spring 72 is forced over the enlarged end 46' of the post to surround the post, and the post containing coil and spring thereon is frictionally press fitted into the passageway of the column with the coil frictionally engaging the upper inner wall surface of the passageway to retain the clamp post in the column.
The base 12' of the assembly of FIG. 6 is constructed like the base 12 of FIGS. 1-5, except that the lower inner edge of each inwardly tapering wall section 18' of base 12' defining the channel 20' is provided with a short inwardly projecting protrusion, or rib, 76 for increased frictionally engagement and grip of lower edge portions of a rectangular rod-shaped element 22' of the supporting frame of a neon display sign.
In operation, the embodiment of the assembly shown in FIG. 6 functions in similar manner to the embodiment of FIGS. 1-5. The C-shaped clamp 38' can move in either direction along the longitudinal axis of the tubular column against the compression force of spring 72 to accommodate and grippingly support glass tubing. Engagement of the reduced diameter lower coil portion 72b of spring 72 with the column passageway shoulder 34' prevents movement of the lower end of the spring downwardly in the column when post 16' moves downwardly, while engagement of the reduced diameter upper coil portion 72a of spring 72 with retaining coil 60' prevents movement of the upper end of the spring upwardly in the column as post 16' moves upwardly. The spring thus provides a biasing force against movement of the C-clamp in either direction along the longitudinal axis of the column.
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An assembly for adjustably supporting a luminous tube of a neon sign comprising a clamp post having a C-shaped end portion for frictionally engaging and retaining an outer surface of a luminous tube therein, a tubular column telescopically receiving the clamp post into one end thereof for movement along the longitudinal axis of the column, a ball-shaped portion on the other end of the column engageable in a semi-spherical socket of a base for positional adjustment of the column and clamp post within a 360° circle of movement, and means on the base for frictionally gripping a support member to provide positional adjustable support of a luminous tube in spaced relation therefrom. The clamp post, tubular column, and base are preferably formed of molded plastic and engage in snap-fit relation. Spring means are provided in the tubular column to bias the clamp post against movement along the longitudinal axis of the column.
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